SOCS regulation of the JAK/STAT signalling pathway (original) (raw)
Transgenic Research
Even though growth hormone (GH) transgenesis has demonstrated potential for improved growth of commercially important species, the hormone excess may result in undesired collateral effects. In this context, the aim of this work was to develop a new model of transgenic zebrafish (Danio rerio) characterized by a muscle-specific overexpression of the GH receptor (GHR) gene, evaluating the effect of transgenesis on growth, muscle structure and expression of growth-related genes. In on line of transgenic zebrafish overexpressing GHR in skeletal muscle, no significant difference in total weight in comparison to non-transgenics was observed. This can be explained by a significant reduction in expression of somatotrophic axis-related genes, in special insulin-like growth factor I (IGF-I). In the same sense, a significant increase in expression of the suppressors of cytokine signaling 1 and 3 (SOCS) was encountered in transgenics. Surprisingly, expression of genes coding for the main myogenic regulatory factors (MRFs) was higher in transgenic than non-transgenic zebrafish. Genes coding for muscle proteins did not follow the MRFs profile, showing a significant decrease in their expression. These results were corroborated by the histological analysis, where a hyperplasic muscle growth was observed in transgenics. In conclusion, our results demonstrated that GHR overexpression does not induce hypertrophic muscle growth in transgenic zebrafish probably because of SOCS impairment of the GHR/IGF-I pathway, culminating in IGF-I and muscle proteins decrease. Therefore, it seems that hypertrophy and hyperplasia follow two different routes for entire muscle growth, both of them triggered by GHR activation, but regulated by different mechanisms.
Journal of Biological Chemistry, 2009
3 The abbreviations used are: IL, interleukin; IL-18BP, IL-18-binding protein; IL-18R␣, IL-18 receptor ␣-chain; IL-1Ra, IL-1 receptor antagonist; ko, knockout; MEF, mouse embryonic fibroblast(s); PBMC, peripheral blood mono-nuclear cell(s); shIL-18R, shRNA to the IL-18R; shRNA, small hairpin RNA; SOCS, suppressor(s) of cytokine signaling; WT, wild type; TNF␣, tumor necrosis factor ␣; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay; PGE 2 , prostaglandin E 2 ; IFN, interferon; ICAM, intercellular cell adhesion molecule; MAPK, mitogen-activated protein kinase; LPS, lipopolysaccharide; siRNA, small interfering RNA.
Cell Death and Differentiation, 2012
Signalling through the janus kinase (JAK)/signal transducer and activator of transcription (Stat) pathway is required at different stages of mammary gland development, and this pathway is frequently hyper-activated in cancer, including tumours of the breast. Stats 3, 5 and 6 have important roles in the differentiation and survival of mammary alveolar cells, but somewhat paradoxically, both Stat3 and 5 can have oncogenic activity in the mammary gland. Constitutive activation of JAK2 could be anticipated to result in hyper-activation of Stats 1, 3, 5 and 6 with concomitant cell transformation, although the outcome is difficult to envisage, particularly since Stats 3 and 5 play opposing roles in normal mammary gland development. Here, we show that expression of a constitutively active JAK2 mutant, JAK2 V617F, leads to hyper-activation of Stat5 in mammary epithelial cells (MECs), and transgenic mice expressing JAK2 V617F specifically in the mammary gland exhibit accelerated alveologenesis during pregnancy and delayed post-lactational regression. Overexpressing JAK2 V617F in MECs in vitro results in elevated proliferation and resistance to cell death. Furthermore, constitutively active JAK2 enhances anchorage-independent cell growth in the presence of a co-operating oncogene and accelerates tumourigenesis in a xenograft model. Taken together, our results provide insights into signalling downstream of constitutively active JAK2 and could be important for understanding the molecular mechanisms of breast tumourigenesis. (MMC) These authors contributed equally to this work.
Regulation of the inflammatory response of vascular endothelial cells by EPAC1
British Journal of Pharmacology, 2012
Life-threatening diseases of the cardiovascular system, like atherosclerosis, are exacerbated by unwanted inflammation within the structures of large blood vessels. This inflammation involves increased permeability of the vascular endothelial cells (VECs) that form the lining of blood vessels, leading to exaggerated extravasation of blood components and accumulation of fluid in the extravascular space. This results in tissue dysfunction and increased secretion of chemokines that attract leukocytes and monocytes to the inflamed endothelium. Cyclic AMP is synthesized in VECs in response to endogenous Gs-coupled receptors and is known to limit cytokine action and reduce endothelial hyperpermeability induced by multiple pro-inflammatory stimuli. The mechanisms underlying this anti-inflammatory action of cyclic AMP are now being elucidated and it is becoming clear that the cyclic AMP sensor, exchange protein activated by cyclic AMP (EPAC1), appears to play a key role in suppressing unwanted inflammation. EPAC1 mediates at least three anti-inflammatory pathways in VECs by down-regulating inflammatory signalling through the induction of the suppressors of cytokine signalling 3 (SOCS-3) gene, limiting integrin-dependent vascular permeability and enhancing endothelial barrier function through the stabilization of VE-cadherin junctions. Given that manipulation of cellular cyclic AMP levels currently forms the basis of many effective pharmaceuticals and that EPAC1 is involved in multiple anti-inflammatory protective processes in VECs, does this make EPAC1 an attractive target for the development of activators capable of eliciting a coordinated programme of 'protection' against the development of endothelial dysfunction? Here we discuss whether EPAC1 represents an attractive therapeutic target for limiting endothelial dysfunction associated with cardiovascular diseases like atherosclerosis. Abbreviations 8-pCPT-2′OMe-cAMP, -(4-chlorophenylthio)-2′-O-methyladenosine-3′, 5′-cyclic monophosphate; AKAP, A-kinase anchoring protein; EPAC, exchange protein activated by cyclic AMP; MAP; microtubule-associated protein BJP British Journal of Pharmacology
Leukemia inhibitory factor: A paracrine mediator of bone metabolism
Growth Factors, 2012
Leukemia inhibitory factor (LIF) is a soluble interleukin-6 family cytokine that regulates a number of physiologic functions, including normal skeletal remodeling. LIF signals through the cytokine co-receptor glycoprotein-130 in complex with its cytokine-specific receptor [LIF receptor (LIFR)] to activate signaling cascades in cells of the skeletal system, including stromal cells, chondrocytes, osteoblasts, osteocytes, adipocytes, and synovial fibroblasts. LIF action on skeletal cells is cell-type specific, and frequently dependent on the state of cell differentiation. This review describes the expression patterns of LIF and LIFR in bone, their regulation by physiological and inflammatory agents, as well as cell-specific influences of LIF on osteoblast, osteoclast, chondrocyte, and adipocyte differentiation. The actions of LIF in normal skeletal growth and maintenance, in pathological states (e.g. autocrine tumor cell signaling and growth in bone) and inflammatory conditions (e.g. arthritis) will be discussed, as well as the signaling pathways activated by LIF and their importance in bone formation and resorption.
An Agent-Based Model of Cellular Dynamics and Circadian Variability in Human Endotoxemia
PLoS ONE, 2013
As cellular variability and circadian rhythmicity play critical roles in immune and inflammatory responses, we present in this study an agent-based model of human endotoxemia to examine the interplay between circadian controls, cellular variability and stochastic dynamics of inflammatory cytokines. The model is qualitatively validated by its ability to reproduce circadian dynamics of inflammatory mediators and critical inflammatory responses after endotoxin administration in vivo. Novel computational concepts are proposed to characterize the cellular variability and synchronization of inflammatory cytokines in a population of heterogeneous leukocytes. Our results suggest that there is a decrease in cell-to-cell variability of inflammatory cytokines while their synchronization is increased after endotoxin challenge. Model parameters that are responsible for IkB production stimulated by NFkB activation and for the production of anti-inflammatory cytokines have large impacts on system behaviors. Additionally, examining time-dependent systemic responses revealed that the system is least vulnerable to endotoxin in the early morning and most vulnerable around midnight. Although much remains to be explored, proposed computational concepts and the model we have pioneered will provide important insights for future investigations and extensions, especially for single-cell studies to discover how cellular variability contributes to clinical implications.
Cell Cycle, 2013
Epigenetic silencing of tumor suppressor genes frequently occurs and may account for their inactivation in cancer cells. We previously demonstrated that miR-29b is a tumor suppressor microRNA (miRNA) that targets de novo DNA-methyltransferases and reduces the global DNA methylation of multiple myeloma (MM) cells. Here, we provide evidence that epigenetic activity of miR-29b leads to promoter demethylation of Suppressor of cytokine signaling-1 (SOCS-1), a hypermethylated tumor suppressor gene. Enforced expression of synthetic miR-29b mimics in MM cell lines resulted in demethylation of SOCS-1 promoter, as assessed by Sequenom MassARRAY EpiTYPER analysis, and protein up-regulation. miR-29b-induced SOCS-1 demethylation was associated to reduced STAT3 phosphorylation and impaired NF-κB activity. Down-regulation of VEGF-A and IL-8 mRNAs could be detected in MM cells transfected with miR-29b mimics as well as in endothelial (HUVEC) or stromal (HS-5) cells treated with conditioned medium from miR-29b-transfected MM cells. Notably, enforced expression of miR-29b mimics increased adhesion of MM cells to HS-5 and reduced migration of both MM and HUVEC cells. These findings suggest that miR-29b is a negative regulator of either MM or endothelial cell migration. Finally, the proteasome inhibitor bortezomib, which induces the expression of miR-29b, decreased global DNA methylation by a miR-29b-dependent mechanism and
Growth hormone (GH)/STAT5 signaling during the growth period in liver of mice overexpressing GH
Journal of molecular endocrinology, 2015
Growth hormone (GH)/STAT5 signaling is desensitized in liver of adult transgenic mice overexpressing GH; however, these animals present greater body size. To assess if the STAT5 pathway is active during the growth period in the liver of these animals, and how signaling modulators participate in this process, growing transgenic mice and normal siblings were evaluated. STAT5 does not respond to an acute GH-stimulus but presents higher basal phosphorylation in liver of growing GH-overexpressing mice. GH receptor and positive modulators GR and HNF1 display greater abundance in transgenic animals, supporting STAT5 activity. Negative modulators CIS and PTP1B are increased in GH-overexpressing mice. Suppressors SOCS2 and SOCS3 exhibit higher mRNA levels in transgenic mice but lower protein content, suggesting they are being degraded. Therefore, STAT5 signaling is increased in liver of GH-transgenic mice during the growth period, with a balance between positive and negative effectors result...
PLoS ONE, 2013
Suppressor of Cytokine Signaling (SOCS)5 is thought to act as a tumour suppressor through negative regulation of JAK/ STAT and epidermal growth factor (EGF) signaling. However, the mechanism/s by which SOCS5 acts on these two distinct pathways is unclear. We show for the first time that SOCS5 can interact directly with JAK via a unique, conserved region in its N-terminus, which we have termed the JAK interaction region (JIR). Co-expression of SOCS5 was able to specifically reduce JAK1 and JAK2 (but not JAK3 or TYK2) autophosphorylation and this function required both the conserved JIR and additional sequences within the long SOCS5 N-terminal region. We further demonstrate that SOCS5 can directly inhibit JAK1 kinase activity, although its mechanism of action appears distinct from that of SOCS1 and SOCS3. In addition, we identify phosphoTyr317 in Shc-1 as a high-affinity substrate for the SOCS5-SH2 domain and suggest that SOCS5 may negatively regulate EGF and growth factor-driven Shc-1 signaling by binding to this site. These findings suggest that different domains in SOCS5 contribute to two distinct mechanisms for regulation of cytokine and growth factor signaling.
Epilepsia, 2011
Purpose: Neuroinflammation appears as a prominent feature of the mesiotemporal lobe epilepsy syndrome (MTLE) that is observed in human patients and animal models. However, the precise temporal relationship of its development during epileptogenesis remains to be determined. The aim of the present study was to investigate (1) the time course and spatial distribution of neuronal death associated with seizure development, (2) the time course of microglia and astrocyte activation, and (3) the kinetics of induction of mRNAs from neuroinflammatoryrelated proteins during the emergence of recurrent seizures. Methods: Experimental MTLE was induced by the unilateral intrahippocampal injection of kainate in C57BL/6 adult mice. Microglial and astrocytic changes in both ipsilateral and contralateral hippocampi were examined by respectively analyzing griffonia simplicifolia (GSA) lectin staining and glial fibrillary acidic protein (GFAP) immunoreactivity. Changes in mRNA levels of selected genes of cytokine and cytokine regulatory proteins (interleukin-1b, IL-1b; interleukin-1 receptor antagonist, IL-1Ra; suppressor of cytokine signaling 3, SOCS3) and enzymes of the eicosanoid pathway (group IVA cytosolic phospholipase A2, cPLA 2 -a; cycloxygenase-2, COX-2) were studied by reverse transcription-quantitative real time polymerase chain reaction. Key Findings: Our data show an immediate cell death occurring in the kainate-injected hippocampus during the initial status epilepticus (SE). A rapid increase of activated lectin-positive cells and GFAP-immunoreactivity was subsequently detected in the ipsilateral hippocampus. In the same structure, Il-1b, IL-1Ra, and COX-2 mRNA were specifically increased during SE and epileptogenesis with a different time course. Conversely, the expression of SOCS3 mRNA, a surrogate marker of interleukin signaling, was mainly increased in the contralateral hippocampus after SE. Significance: Our data show that specific neuroinflammatory pathways are activated in a time-and structuredependent manner with putative distinct roles in epileptogenesis.
Suppressor of cytokine signaling 1 blocks mitosis in human melanoma cells
Cellular and Molecular Life Sciences, 2013
Hypermethylation of SOCS genes is associated with many human cancers, suggesting a role as tumor suppressors. As adaptor molecules for ubiquitin ligases, SOCS proteins modulate turnover of numerous target proteins. Few SOCS targets identified so far have a direct role in cell cycle progression; the mechanism by which SOCS regulate the cell cycle thus remains largely unknown. Here we show that SOCS1 overexpression V. Parrillas Á L. Martínez-Muñoz Á B. L. Holgado Á G. Cascio Á P. Lucas Á J. M. Rodríguez-Frade Á M. Mellado (
SOCS3: An essential physiological inhibitor of signaling by interleukin-6 and G-CSF family cytokines
JAK-STAT, 2013
SOCS3 is an inducible negative feedback inhibitor of cytokine signaling. Conditional deletion of SOCS3 in mice using the Cre-lox system has now been applied to a range of cell types in the steady-state and under inflammatory, pathogenic, or tumorigenic stress, with the resulting phenotypes demonstrating the effects of SOCS3 in physiological and disease contexts. Together with recent structural and biochemical studies on the mechanisms of SOCS3 binding to cytokine receptors and associated kinases, we now have a better understanding of the non-redundant roles of SOCS3 in the inhibition of cytokine signaling via the receptors gp130, G-CSFR, leptinR, and IL-12Rβ. This review discusses the known functional activities of SOCS3 in fertility and development, inflammation, innate and adaptive immunity, and malignancy as determined by genetic studies in mice.
PLoS ONE, 2013
Sustained hedgehog (Hh) signaling mediated by the GLI transcription factors is implicated in many types of cancer. Identification of Hh/GLI target genes modulating the activity of other pathways involved in tumor development promise to open new ways for better understanding of tumor development and maintenance. Here we show that SOCS1 is a direct target of Hh/GLI signaling in human keratinocytes and medulloblastoma cells. SOCS1 is a potent inhibitor of interferon gamma (IFN-y)/STAT1 signaling. IFN-у/STAT1 signaling can induce cell cycle arrest, apoptosis and anti-tumor immunity. The transcription factors GLI1 and GLI2 activate the SOCS1 promoter, which contains five putative GLI binding sites, and GLI2 binding to the promoter was shown by chromatin immunoprecipitation. Consistent with a role of GLI in SOCS1 regulation, STAT1 phosphorylation is reduced in cells with active Hh/GLI signaling and IFN-у/STAT1 target gene activation is decreased. Furthermore, IFN-у signaling is restored by shRNA mediated knock down of SOCS1. Here, we identify SOCS1 as a novel Hh/GLI target gene, indicating a negative role of Hh/GLI pathway in IFN-y/STAT1 signaling.
Veterinary Research, 2014
To differentiate between the contribution of mammary epithelial cells (MEC) and infiltrating immune cells to gene expression profiles of mammary tissue during early stage mastitis, we investigated in goats the in vivo transcriptional response of MEC to an experimental intra mammary infection (IMI) with Staphylococcus aureus, using a non-invasive RNA sampling method from milk fat globules (MFG). Microarrays were used to record gene expression patterns during the first 24 hours post-infection (hpi). This approach was combined with laser capture microdissection of MEC from frozen slides of mammary tissue to analyze some relevant genes at 30 hpi. During the early stages post-inoculation, MEC play an important role in the recruitment and activation of inflammatory cells through the IL-8 signalling pathway and initiate a sharp induction of innate immune genes predominantly associated with the proinflammatory response. At 30 hpi, MEC express genes encoding different acute phase proteins, including SAA3, SERPINA1 and PTX3 and factors, such as S100A12, that contribute directly to fighting the infection. No significant change in the expression of genes encoding caseins was observed until 24 hpi, thus validating our experimental model to study early stages of infection before the occurrence of tissue damage, since the milk synthesis function is still operative. This is to our knowledge the first report showing in vivo, in goats, how MEC orchestrate the innate immune response to an IMI challenge with S. aureus. Moreover, the non-invasive sampling method of mammary representative RNA from MFG provides a valuable tool to easily follow the dynamics of gene expression in MEC to search for sensitive biomarkers in milk for early detection of mastitis and therefore, to successfully improve the treatment and thus animal welfare.
p53-Dependent Transcriptional Responses to Interleukin-3 Signaling
PLoS ONE, 2012
p53 is critical in the normal response to a variety of cellular stresses including DNA damage and loss of p53 function is a common feature of many cancers. In hematological malignancies, p53 deletion is less common than in solid malignancies but is associated with poor prognosis and resistance to chemotherapy. Compared to their wild-type (WT) counterparts, hematopoietic progenitor cells lacking p53 have a greater propensity to survive cytokine loss, in part, due to the failure to transcribe Puma, a proapoptotic Bcl-2 family member. Using expression arrays, we have further characterized the differences that distinguish p53 2/2 cells from WT myeloid cells in the presence of Interleukin-3 (IL-3) to determine if such differences contribute to the increased clonogenicity and survival responses observed in p53 2/2 cells. We show that p53 2/2 cells have a deregulated intracellular signaling environment and display a more rapid and sustained response to IL-3. This was accompanied by an increase in active ERK1/2 and a dependence on an intact MAP kinase signaling pathway. Contrastingly, we find that p53 2/2 cells are independent on AKT for their survival. Thus, loss of p53 in myeloid cells results in an altered transcriptional and kinase signaling environment that favors enhanced cytokine signaling.
Not4 enhances JAK/STAT pathway-dependent gene expression in Drosophila and in human cells
The FASEB Journal, 2012
The JAK/STAT pathway is essential for organogenesis, innate immunity, and stress responses in Drosophila melanogaster. The JAK/STAT pathway and its associated regulators have been highly conserved in evolution from flies to humans. We have used a genome-wide RNAi screen in Drosophila S2 cells to identify regulators of the JAK/STAT pathway, and here we report the characterization of Not4 as a positive regulator of the JAK/STAT pathway.
t(8;9)(p22;p24)/PCM1-JAK2 Activates SOCS2 and SOCS3 via STAT5
PLoS ONE, 2013
Fusions of the tyrosine kinase domain of JAK2 with multiple partners occur in leukemia/lymphoma where they reportedly promote JAK2-oligomerization and autonomous signalling, Affected entities are promising candidates for therapy with JAK2 signalling inhibitors. While JAK2-translocations occur in myeloid, B-cell and T-cell lymphoid neoplasms, our findings suggest their incidence among the last group is low. Here we describe the genomic, transcriptional and signalling characteristics of PCM1-JAK2 formed by t(8;9)(p22;p24) in a trio of cell lines established at indolent (MAC-1) and aggressive (MAC-2A/2B) phases of a cutaneous T-cell lymphoma (CTCL). To investigate signalling, PCM1-JAK2 was subjected to lentiviral knockdown which inhibited 7 top upregulated genes in t(8;9) cells, notably SOCS2/3. SOCS3, but not SOCS2, was also upregulated in a chronic eosinophilic leukemia bearing PCM1-JAK2, highlighting its role as a central signalling target of JAK2 translocation neoplasia. Conversely, expression of GATA3, a key T-cell developmental gene silenced in aggressive lymphoma cells, was partially restored by PCM1-JAK2 knockdown. Treatment with a selective JAK2 inhibitor (TG101348) to which MAC-1/2A/2B cells were conspicuously sensitive confirmed knockdown results and highlighted JAK2 as the active moiety. PCM1-JAK2 signalling required pSTAT5, supporting a general paradigm of STAT5 activation by JAK2 alterations in lymphoid malignancies. MAC-1/2A/2B -the first JAK2-translocation leukemia/lymphoma cell lines described -display conspicuous JAK/STAT signalling accompanied by T-cell developmental and autoimmune disease gene expression signatures, confirming their fitness as CTCL disease models. Our data support further investigation of SOCS2/3 as signalling effectors, prognostic indicators and potential therapeutic targets in cancers with JAK2 rearrangements. Citation: Ehrentraut S, Nagel S, Scherr ME, Schneider B, Quentmeier H, et al. (2013) t(8;9)(p22;p24)/PCM1-JAK2 Activates SOCS2 and SOCS3 via STAT5. PLoS ONE 8(1): e53767.
Growth Hormone (GH) and Cardiovascular System
International journal of molecular sciences, 2018
This review describes the positive effects of growth hormone (GH) on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on vessels improving oxidative stress imbalance and endothelial dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease, inducing a neovascularization process that finally increases flow in ischemic tissues. We include some preliminary data from a trial in which GH or placebo is given to elderly people suffering from critical limb ischemia, showing some of the benefits of the hormone on plasma markers of inflammation, and the safety of GH administration during short periods of time, even in diabetic patients. We also analyze how Klotho is strongly related to GH, inducing, after being released from the damaged vascular endothelium, the pit...
Nutrition Journal, 2015
Background: Antenatal vitamin D 3 (vitD 3) supplementation significantly increases maternal and neonatal 25-hydroxyvitamin D 3 (25(OH)D 3) concentration, yet the effect of an improvement in maternal-fetal vitamin D status on the neonatal immune response is unclear. Method: To assess the effect of prenatal vitD 3 supplementation on cord blood T cell function, healthy pregnant Bangladeshi women (n = 160) were randomized to receive either oral 35,000 IU/week vitD 3 or placebo from 26 to 29 weeks of gestation to delivery. In a subset of participants (n = 80), cord blood mononuclear cells (CBMC) were cultured, non-adherent lymphocytes were isolated to assess T cell cytokine responses to phytohemagglutinin (PHA) and anti-CD3/anti-CD28 (iCD3/iCD28), measured by multiplex assay. In 12 participants, lymphocyte gene expression profiles were analyzed by PCR array. Result: In supplemented group, increased concentrations of IL-10 (P < 0.000) and TNF-α (P = 0.05) with iCD3/iCD28 stimulation and IFN-γ (p = 0.05) with PHA stimulation were obtained compared to placebo group. No differences in the gene expression profile were noted between the two groups. However, PHA stimulation significantly induced the expression of genes encoding Th1 and Th2 cytokines and down-regulated a number of genes involved in T-cell development, proliferation and differentiation of B cells, signal transduction pathway, transcriptional regulation and pattern recognition receptors (PRRs) in the vitamin D group (vitD group). Conclusion: Third-trimester high-dose vitD 3 supplementation in healthy pregnant women had balanced effects on biomarkers of cord blood Th1 and Th2 responses. Trial registration: ClinicalTrials.gov (NCT01126528).
Bioinformatics and biology insights, 2017
Pathogen-host protein-protein interaction systems examine the interactions between the protein repertoires of 2 distinct organisms. Some of these pathogen proteins interact with the host protein system and may manipulate it for their own advantages. In this work, we designed an R script by concatenating 2 functions called rowDM and rowCVmed to infer pathogen-host interaction using previously reported microarray data, including host gene enrichment analysis and the crossing of interspecific domain-domain interactions. We applied this script to the -host system to describe pathogen survival mechanisms from human, mouse, and Gene Expression Omnibus series. Our outcomes exhibited similar results with previously reported microarray analyses, but we found other important proteins that could contribute to toxoplasma pathogenesis. We observed that ROP38 is the most differentially expressed protein among toxoplasma strains. Enrichment analysis and KEGG mapping indicated that the human retina...
JAK2 mutants (e.g., JAK2V617F) and their importance as drug targets in myeloproliferative neoplasms
JAK-STAT, 2013
The Janus kinase 2 (JAK2) mutant V617F and other JAK mutants are found in patients with myeloproliferative neoplasms and leukemias. Due to their involvement in neoplasia and inflammatory disorders, Janus kinases are promising targets for kinase inhibitor therapy. Several small-molecule compounds are evaluated in clinical trials for myelofibrosis, and ruxolitinib (INCB018424, Jakafi®) was the first Janus kinase inhibitor to receive clinical approval. In this review we provide an overview of JAK2V617F signaling and its inhibition by small-molecule kinase inhibitors. In addition, myeloproliferative neoplasms are discussed regarding the role of JAK2V617F and other mutant proteins of possible relevance. We further give an overview about treatment options with special emphasis on possible combination therapies.
IOP Conference Series: Earth and Environmental Science
Pathogenesis of dengue infection is still obscure. Recently, the role of microRNA has been associated with the cytokine storm which leads to plasma leakage in endothelial cells. The objective of our study was to determine whether particular microRNA is overexpressed in PBMCs infected with DENV and to assess its correlation to the expression of suppressor of cytokine signaling 3 (SOCS3) proteins to increase the production of pro-inflammatory cytokines. We report the result of a preliminary study on the expression of microRNA hsa-let-7e. The peripheral blood mononuclear cells (PBMCs) from the healthy volunteer were infected with the clinical isolate of DENV-2. RNA was extracted with miRCURYLNA TM Exiqon. Quantitative Real-Time PCR was used to measure the relative expression of hsa-let-7e micro RNA and the mRNA of SOCS3 proteins. MicroRNA hsa-let-7e expression was increased in PBMCs upon DENV-2 infection. The relative expression of hsa-let-7e is detected at 1.46 folds relative to uninfected PBMCs in 4 hours post-infection and decreased in 19 hours post infection. In contrast, the expression of mRNA of SOCS3 was inversely expressed with hsalet-7 expression. MicroRNA was overexpressed in PBMCs upon infection with DENV-2. This microRNA may bind the SOCS3 and contribute to the pathogenesis of dengue infection.
Non-Coding RNA Sequencing of Equine Endometrium During Maternal Recognition of Pregnancy
Genes
Maternal recognition of pregnancy (MRP) in the mare is not well defined. In a non-pregnant mare, prostaglandin F2α (PGF) is released on day 14 post-ovulation (PO) to cause luteal regression, resulting in loss of progesterone production. Equine MRP occurs prior to day 14 to halt PGF production. Studies have failed to identify a gene candidate for MRP, so attention has turned to small, non-coding RNAs. The objective of this study was to evaluate small RNA (<200 nucleotides) content in endometrium during MRP. Mares were used in a cross-over design with each having a pregnant and non-mated cycle. Each mare was randomly assigned to collection day 11 or 13 PO (n = 3/day) and endometrial biopsies were obtained. Total RNA was isolated and sequencing libraries were prepared using a small RNA library preparation kit and sequenced on a HiSeq 2000. EquCab3 was used as the reference genome and DESeq2 was used for statistical analysis. On day 11, 419 ncRNAs, representing miRNA, snRNA, snoRNA, ...
In vitro significance of SOCS-3 and SOCS-4 and potential mechanistic links to wound healing
Scientific reports, 2017
Wound healing and the management of chronic wounds represent a significant burden on the NHS. Members of the suppressor of cytokine signalling (SOCS) family have been implicated in the regulation of a range of cellular processes. The current study aims to explore the importance of SOCS-3 and SOCS-4 in regulating cellular traits associated with wound healing. SOCS-3 over-expression and SOCS-4 knockdown mutant lines were generated and verified using q-PCR and western blotting in human keratinocytes (HaCaT) and endothelial cells (HECV). Over-expression of SOCS-3 resulted in a significantly reduced proliferative rate in HaCaT keratinocytes and also enhanced the tubule formation capacity of HECV cells. SOCS-4 knockdown significantly reduced HaCaT migration and HECV cell tubule formation. Suppression of SOCS-4 influenced the responsiveness of HaCaT and HECV cells to EGF and TGFβ and resulted in a dysregulation of phospho-protein expression in HaCaT cells. SOCS-3 and SOCS-4 appear to play ...
PLOS ONE
Muscles of older animals are more susceptible to injury and regenerate poorly, in part due to a persistent inflammatory response. The janus kinase (Jak)/signal transducer and activator of transcription (Stat) pathway mediates inflammatory signaling and is tightly regulated by the suppressor of cytokine signaling (SOCS) proteins, especially SOCS3. SOCS3 expression is altered in the muscle of aged animals and may contribute to the persistent inflammation and impaired regeneration. To test this hypothesis, we performed myotoxic injuries on mice with a tamoxifen-inducible deletion of SOCS3 specifically within the muscle stem cell compartment. Muscle stem cell-specific SOCS3 deletion reduced muscle mass at 14 days post-injury (-14%, P < 0.01), altered the myogenic transcriptional program, and reduced myogenic fusion based on the number of centrally-located nuclei per muscle fiber. Despite the delay in myogenesis, muscles with a muscle stem cell-specific deletion of SOCS3 were still able to regenerate after a single bout or multiple bouts of myotoxic injury. A reduction in SOCS3 expression in muscle stem cells is unlikely to be responsible for the incomplete muscle repair in aged animals.
Experimental Biology and Medicine, 2011
Although leptin has been found to be implicated in obesity-related breast carcinogenesis in postmenopausal women, the molecular mechanisms involved are yet to be defined. Recently, the antiapoptotic gene survivin has been recognized as a target gene for leptin in breast cancer. The aim of this study was to investigate the effect of leptin on the expression of survivin and on the transcriptional activity of its promoter in MCF-7 breast cancer cells. We also studied the potential involvement of SOCS-3 (a negative regulator of leptin's main signaling pathway JAK2/STAT3) in the expression of leptin-mediated survivin. Our results showed a significant increase in the mRNA (dose-dependent increase of 40–70%) and protein expression levels of survivin 24 h post-leptin treatment, which was followed by a significant decrease at 48 and 72 h (of 60–70%). In accordance, a chromatin immunoprecipitation assay revealed an initial strong binding of STAT3 to the survivin promoter, which was no lon...
JAK-STAT Pathway Inhibition and their Implications in COVID-19 Therapy
Postgraduate Medicine
As the incidence of COVID-19 increases with time, more and more efforts are made to pave a way out for the therapeutic strategies to deal with the disease progression. Inflammation being a significant influencer in COVID-19 patients, it drives our focus onto the signaling cascades of the JAK/STAT pathway. JAK phosphorylation mediated by cytokine receptor activation leads to phosphorylation of STATs that translocate into the nucleus to translate for inflammatory mediators. The SARS-CoV-2 structural proteins like spike, nucleocapsid, membrane and envelope proteins along with the non-structural proteins 1-16 including proteases like 3CL pro and PL pro promote its entry and survival in hosts. The SARS-CoV-2 infection triggers inflammation via the JAK/STAT pathway leading to recruitment of pneumocytes, endothelial cells, macrophages, monocytes, lymphocytes, natural killer cells and dendritic cells progressing towards cytokine storm. This produces various inflammatory markers in the host that determine the disease severity. The JAK/STAT signaling also mediates immune responses via B cell and T cell differentiation.With an attempt to reduce excessive inflammation, JAK/STAT inhibitors like Ruxolitinib, Baricitinib, Tofacitinib have been employed that mediate its actions via suppressors of cytokine signaling, cytokine inducible SH2 containing protein, Protein inhibitor of activated STAT and protein tyrosine phosphatases. Even though they are implicated with multiple adverse effects, the regulatory authorities have supported its use, and numerous clinical trials are in progress to prove their safety and efficacy. On the contrary, the exact mechanism of JAK/STAT inhibition at molecular levels remains speculative for which further investigations are required.
Curcumin attenuates hepatic fibrosis and insulin resistance induced by bile duct ligation in rats
British Journal of Nutrition
Recent studies have strongly indicated the hepatoprotective effect of curcumin; however, the precise mechanisms are not well understood. This study aimed to determine the protective effect of curcumin on hepatic damage and hepatic insulin resistance in biliary duct ligated (BDL) fibrotic rat model. To accomplish this, male Wistar rats were divided into four groups (eight for each): sham group, BDL group, sham+Cur group and BDL+Cur group. The last two groups received curcumin at a dose of 100 mg/kg daily for 4 weeks. The mRNA/protein expression levels of Ras-related C3 botulinum toxin substrate 1 (Rac1), Rac1-GTP, dinucleotide phosphate oxidase 1 (NOX1), signal transducer and activator of transcription 3 (STAT3), suppressor of cytokine signalling 3 (SOCS3), insulin receptor substrate 1 (IRS1), extracellular signal-regulated kinase 1 (ERK1), specific protein 1 (Sp1) and hypoxia-inducible factor-1α (HIF-1α) were measured by real-time PCR and Western blotting, respectively. Fasting bloo...
PLOS ONE, 2015
Schistosomiasis is a common debilitating human parasitic disease in (sub)tropical areas, however, schistosome infections can also protect against a variety of inflammatory diseases. This has raised broad interest in the mechanisms by which Schistosoma modulate the immune system into an anti-inflammatory and regulatory state. Human dendritic cells (DCs) show many phenotypic changes upon contact with Schistosoma mansoni soluble egg antigens (SEA). We here show that oxidation of SEA glycans, but not heat-denaturation, abrogates the capacity of SEA to suppress both LPS-induced cytokine secretion and DC proliferation, indicating an important role of SEA glycans in these processes. Remarkably, interaction of SEA glycans with DCs results in a strongly increased expression of Suppressor Of Cytokine Signalling1 (SOCS1) and SH2-containing protein tyrosine Phosphatase-1 (SHP1), important negative regulators of TLR4 signalling. In addition, SEA induces the secretion of transforming growth factor β (TGF-β), and the surface expression of the costimulatory molecules Programmed Death Ligand-1 (PD-L1) and OX40 ligand (OX40L), which are known phenotypic markers for the capacity of DCs to polarize naïve T cells into Th2/Treg cell subsets. Inhibition of mannose receptor (MR)-mediated internalization of SEA into DCs by blocking with allyl α-D-mannoside or anti-MR antibodies, significantly reduced SOCS1 and SHP1 expression. In conclusion, we demonstrate that SEA glycans are essential for induction of enhanced SOCS1 and SHP1 levels in DCs via the MR. Our data provide novel mechanistic evidence for the potential of S. mansoni SEA glycans to modulate human DCs, which may contribute to the capacity of SEA to down-regulate inflammatory responses.
Blood Cancer Journal, 2011
Polycythemia vera (PV), essential thrombocythemia and primary myelofibrosis, are myeloproliferative neoplasms (MPNs) with distinct clinical features and are associated with the JAK2V617F mutation. To identify genomic anomalies involved in the pathogenesis of these disorders, we profiled 87 MPN patients using Affymetrix 250K single-nucleotide polymorphism (SNP) arrays. Aberrations affecting chr9 were the most frequently observed and included 9pLOH (n ¼ 16), trisomy 9 (n ¼ 6) and amplifications of 9p13.3-23.3 (n ¼ 1), 9q33.1-34.13 (n ¼ 1) and 9q34.13 (n ¼ 6). Patients with trisomy 9 were associated with elevated JAK2V617F mutant allele burden, suggesting that gain of chr9 represents an alternative mechanism for increasing JAK2V617F dosage. Gene expression profiling of patients with and without chr9 abnormalities (þ 9, 9pLOH), identified genes potentially involved in disease pathogenesis including JAK2, STAT5B and MAPK14. We also observed recurrent gains of 1p36.31-36.33 (n ¼ 6), 17q21.2-q21.31 (n ¼ 5) and 17q25.1-25.3 (n ¼ 5) and deletions affecting 18p11.31-11.32 (n ¼ 8). Combined SNP and gene expression analysis identified aberrations affecting components of a noncanonical PRC2 complex (EZH1, SUZ12 and JARID2) and genes comprising a 'HSC signature' (MLLT3, SMARCA2 and PBX1). We show that NFIB, which is amplified in 7/87 MPN patients and upregulated in PV CD34 þ cells, protects cells from apoptosis induced by cytokine withdrawal.
Scientific Reports, 2016
Cancer-associated fibroblasts (CAFs), the principal components of the tumor stroma, play a central role in cancer development and progression. As an important regulator of the crosstalk between breast cancer cells and CAFs, the cytokine leptin has been associated to breast carcinogenesis. The nuclear Farnesoid X Receptor-(FXR) seems to exert an oncosuppressive role in different tumors, including breast cancer. Herein, we demonstrated, for the first time, that the synthetic FXR agonist GW4064, inhibiting leptin signaling, affects the tumor-promoting activities of CAFs in breast malignancy. GW4064 inhibited growth, motility and invasiveness induced by leptin as well as by CAF-conditioned media in different breast cancer cell lines. These effects rely on the ability of activated FXR to increase the expression of the suppressor of the cytokine signaling 3 (SOCS3) leading to inhibition of leptin-activated signaling and downregulation of leptin-target genes. In vivo xenograft studies, using MCF-7 cells alone or co-injected with CAFs, showed that GW4064 administration markedly reduced tumor growth. Interestingly, GW4064-treated tumors exhibited decreased levels of leptin-regulated proteins along with a strong staining intensity for SOCS3. Thus, FXR ligands might represent an emerging potential anti-cancer therapy able to block the tumor supportive role of activated fibroblasts within the breast microenvironment. Leptin is a multifunctional adipokine with several biological activities ranging from regulating food intake and energy metabolism to modulating many other processes, such as reproduction, lactation, haematopoiesis, immunity, cell differentiation and importantly carcinogenesis 1,2. A growing body of evidence indicates a crucial role of leptin in the pathogenesis of breast cancer. Particularly, it has been extensively demonstrated that this adipokine is an important pro-inflammatory, proangiogenic, pro-invasive and mitogenic factor 1-3 , whose actions are strengthened through interaction with other different signaling molecules such as estrogens, growth factors and inflammatory cytokines 4-7. Leptin may act via endocrine, paracrine, and autocrine manner in breast cancer 8. Indeed, in addition to the adipose tissue that represents the main source of leptin, normal and malignant breast tissue also secrete this adipokine 9. Leptin and its receptor (ObR) are overexpressed in breast cancer compared with non-transformed mammary gland and benign mammary tumors and both molecules positively correlated with poor prognosis in primary breast carcinoma 10,11. Moreover, we recently demonstrated that leptin is also secreted by a subpopulation of fibroblasts, known as cancer-associated fibroblasts (CAFs), within the tumor microenvironment, and that CAFs-secreted leptin promotes proliferation, migration, and invasiveness of breast cancer cells 12 .
Suppression of Autoimmune Arthritis by Small Molecule Inhibitors of the JAK/STAT Pathway
Pharmaceuticals, 2010
A skewed ratio of pro-inflammatory to anti-inflammatory cytokines, elevated growth factor synthesis and T-and B-lymphocyte activation are 3 hallmarks of rheumatoid arthritis (RA) pathology. Interleukin-6 (IL-6), IL-7, IL-17, IL-12/IL-23 and growth factors, granulocyte macrophage-colony stimulating factor, IL-3, and erythropoietin activate the Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) pathway. Evidence showed that STAT protein phosphorylation (p-STAT) by activated JAKs is permissive for p-STAT to act as transcription factors by binding to STAT-responsive gene promoter sequences. This event is critical for perpetuating RA, in part, by up-regulating pro-inflammatory cytokine gene transcription. Activation of JAK/STAT by cytokines and growth factors can induce 'cross-talk' with other signaling pathways by which Stress-Activated Protein/Mitogen-Activated Protein Kinase (SAP/MAPK) and Phosphatidylinositide-3-Kinase (PI3K)-mediated signaling are also activated. JAK-specific small molecule inhibitors (SMIs) were developed to test whether JAK/STAT pathway blockade would regulate autoimmune-mediated inflammation. JAK-specific SMI blockade inhibited p-STAT induced by pro-inflammatory cytokines in vitro. Systemically administered JAK-specific SMI blockade also ameliorated biomarkers of inflammation in well-validated arthritis animal models. A few JAK-specific SMIs have made their way into RA clinical trials. In fact, the JAK3-specific SMI, CP-690,500 is the first JAK/STAT SMI to be assessed for clinical efficacy in a Phase III RA trial.
2021
Oral cancer is a major global health problem with high incidence and low survival rates. The oral cavity contains biofilms as dental plaques that harbour both Gram-negative and Gram-positive bacterial antigens, lipopolysaccharide (LPS) and lipoteichoic acid (LTA), respectively. LPS and LTA are known to stimulate cancer cell growth, and the bioactive phytochemical capsaicin has been reported to reverse this effect. Here, we tested the efficacy of oral cancer chemotherapy treatment with capsaicin in the presence of LPS, LTA or the combination of both antigens. LPS and LTA were administered to Cal 27 oral cancer cells prior to and/or concurrently with capsaicin, and the treatment efficacy was evaluated by measuring cell proliferation and apoptotic cell death. We found that while capsaicin inhibits oral cancer cell proliferation and metabolism (MT Glo assay) and increases cell death (Trypan blue exclusion assay and Caspase 3/7 expression), its anti-cancer effect was significantly reduce...
Therapeutic advances in cardiovascular disease, 2018
Revascularization for chronic limb-threatening ischemia (CLTI) is necessary to alleviate symptoms and wound healing. When it fails or is not possible, there are few alternatives to avoid limb amputation in these patients. Although experimental studies with stem cells and growth factors have shown promise, clinical trials have demonstrated inconsistent results because CLTI patients generally need arteriogenesis rather than angiogenesis. Moreover, in addition to the perfusion of the limb, there is the need to improve the neuropathic response for wound healing, especially in diabetic patients. Growth hormone (GH) is a pleiotropic hormone capable of boosting the aforementioned processes and adds special benefits for the redox balance. This hormone has the potential to mitigate symptoms in ischemic patients with no other options and improves the cardiovascular complications associated with the disease. Here, we discuss the pros and cons of using GH in such patients, focus on its effects ...
JAK/STAT Cytokine Signaling at the Crossroad of NK Cell Development and Maturation
Frontiers in Immunology
Natural Killer (NK) cells are cytotoxic lymphocytes of the innate immune system and play a critical role in anti-viral and anti-tumor responses. NK cells develop in the bone marrow from hematopoietic stem cells (HSCs) that differentiate through common lymphoid progenitors (CLPs) to NK lineage-restricted progenitors (NKPs). The orchestrated action of multiple cytokines is crucial for NK cell development and maturation. Many of these cytokines such as IL-2, IL-7, IL-12, IL-15, IL-21, IL-27, and interferons (IFNs) signal via the Janus Kinase / Signal Transducer and Activator of Transcription (JAK/STAT) pathway. We here review the current knowledge about these cytokines and the downstream signaling involved in the development and maturation of conventional NK cells and their close relatives, innate lymphoid cells type 1 (ILC1). We further discuss the role of suppressor of cytokine signaling (SOCS) proteins in NK cells and highlight their potential for therapeutic application.
International Journal of Molecular Sciences
An increased focus is being placed on the tumorigenesis and contexture of tumor microenvironment in hematopoietic and solid tumors. Despite recent clinical revolutions in adoptive T-cell transfer approaches and immune checkpoint blockade, tumor microenvironment is a major obstacle to tumor regression in B-cell malignancies. A transcriptional alteration of coding and non-coding RNAs, such as microRNAs (miRNAs), has been widely demonstrated in the tumor microenvironment of B-cell malignancies. MiRNAs have been associated with different clinical-biological forms of B-cell malignancies and involved in the regulation of B lymphocyte development, maturation, and function, including B-cell activation and malignant transformation. Additionally, tumor-secreted extracellular vesicles regulate recipient cell functions in the tumor microenvironment to facilitate metastasis and progression by delivering miRNA contents to neighboring cells. Herein, we focus on the interplay between miRNAs and tum...
LPS Regulates SOCS2 Transcription in a Type I Interferon Dependent Autocrine-Paracrine Loop
PLoS ONE, 2012
Recent studies suggest that SOCS2 is involved in the regulation of TLR signaling. In this study, we found that the expression of SOCS2 is regulated in human monocyte-derived DC by ligands stimulating TLR2, 3, 4, 5, 8 and 9 signaling. SOCS2 induction by LPS was dependent on the type I IFN regulated transcription factors IRF1 and IRF3 as shown by using silencing RNAs for IRFs. Blocking endogenous type I IFN signaling, by neutralizing antibodies to the receptor IFNAR2, abolished SOCS2 mRNA expression after TLR4 stimulation. Transcription factors STAT3, 5 and 6 displayed putative binding sites in the promoter regions of the human SOCS2 gene. Subsequent silencing experiments further supported that STAT3 and STAT5 are involved in LPS induced SOCS2 regulation. In mice we show that SOCS2 mRNA induction is 45% lower in bone marrow derived macrophages derived from MyD88 2/2 mice, and do not increase in BMMs from IRF3 2/2 mice after BCG infection. In conclusion, our results suggest that TLR4 signaling indirectly increases SOCS2 in late phase mainly via the production of endogenous type I IFN, and that subsequent IFN receptor signaling activates SOCS2 via STAT3 and STAT5.
Growth Hormone (GH) and Wound Healing
Wound Healing - Current Perspectives [Working Title], 2018
Wound healing is complex and numerous factors overlap perfectly with the goal of wound closure. Among them, we will focus on a large amount of experimental and clinical evidence on the action of GH in wound repair. We will analyze how the physiological rhythm of GH secretion influences this process, and also one of the most important signaling pathways that mediate the effects of GH on tissue regeneration. The role of IGF-1 and the factors that stimulate GH secretion and that have also been shown to improve healing will also be reviewed. In addition, it will be analyzed the cellular senescence process, which plays a key role in nonhealing wounds associated with chronic diseases. The benefit of GH in this last circumstance is especially important. The lesions associated with catabolic states, mainly burns, are considered a delicate situation in which it is extraordinarily difficult to act with growth factors due to the fragile situation of these patients, often children. The positive action of GH in these states will also be described. In summary, we will analyze many evidences about the beneficial effects of GH and its main secretagogues in the healing of wounds.
Gene therapy with Neurogenin3, Betacellulin and SOCS-1 Reverses Diabetes in NOD Mice
Gene therapy, 2015
Islet transplantation for Type 1 diabetes is limited by a shortage of donor islets and requirement for immunosuppression. We approached this problem by inducing in vivoislet neogenesis in NOD diabetic mice, a model of autoimmune diabetes. We demonstrate that gene therapy with helper-dependent adenovirus (HDAd) carrying neurogenin3, an islet lineage-defining transcription factor and betacellulin, an islet growth factor, leads to the induction of periportal insulin-positive cell clusters in the liver, which are rapidly destroyed. To specifically accord protection to these 'neo-islets' from cytokine-mediated destruction, we overexpressed suppressor of cytokine signaling 1 (SOCS1) gene, using a rat insulin promoter in combination with neurogenin3 and betacellulin. With this approach, about half of diabetic mice attained euglycemia sustained for over 4 months, regain glucose tolerance and appropriate glucose-stimulated insulin secretion. Histological analysis revealed periportal ...
Scientific Reports, 2019
Macrophages orchestrate immune responses by sensing and responding to pathogen-associated molecules. These responses are modulated by prior conditioning with cytokines such as interferons (IFNs). Type I and II IFN have opposing functions in many biological scenarios, yet macrophages directly stimulated with Type I or II IFN activate highly overlapping gene expression programs. We hypothesized that a sequential conditioning-stimulation approach would reveal with greater specificity the differential effects of Type I and II IFN on human macrophages. By first conditioning with IFN then stimulating with toll-like receptor ligands and cytokines, followed by genome-wide RNA-seq analysis, we identified 713 genes whose expression was unaffected by IFN alone but showed potentiated or diminished responses to a stimulus after conditioning. For example, responses to the cytokine TNF were restricted by Type II IFN conditioning but potentiated by Type I IFN conditioning. We observed that the effects of IFN were not uniformly pro-or anti-inflammatory, but highly gene-specific and stimulus-specific. By assessing expression levels of key signal transducers and characterizing chromatin accessibility by ATAC-seq, we identify the likely molecular mechanisms underlying Type I and Type IIspecific effects, distinguishing between modulation of cytoplasmic signaling networks and the nuclear epigenome that synergistically regulate macrophage immune responses.
Autophagy facilitates cytokine-induced ICAM-1 expression
Innate immunity, 2014
ICAM-1 can be induced by inflammatory cytokines such as IFN-γ and TNF-α. This study investigated whether autophagy regulates ICAM-1 given that autophagy facilitates signaling of these two cytokines. Exogenous IFN-γ induced ICAM-1 in human lung epithelial A549 cells carrying wild type p53, a transcription factor reported for ICAM-1, but not in PC14PE6/AS2 (AS2) cells carrying mutated p53. However, IFN-γ also induced ICAM-1 in A549 cells with short hairpin RNA-silenced p53. No changes in IFN-γ receptor expression were observed in AS2 cells, but IFN-γ-activated Jak2/STAT1/IFN regulatory factor 1 was markedly decreased. In AS2 cells, increased levels of reactive oxygen species induced the activation of Src homology domain-containing phosphatase 2 (SHP2), while SHP2 was essential for IFN-γ resistance. AS2 cells showed autophagy resistance, and the manipulation of the autophagy pathway altered IFN-γ resistance. Aberrant Bcl-2 expression and mammalian target of rapamycin activation contrib...
Targeting substrate-site in Jak2 kinase prevents emergence of genetic resistance
Scientific Reports, 2015
Emergence of genetic resistance against kinase inhibitors poses a great challenge for durable therapeutic response. Here, we report a novel mechanism of JAK2 kinase inhibition by fedratinib (TG101348) that prevents emergence of genetic resistance. Using in vitro drug screening, we identified 211 amino-acid substitutions conferring resistance to ruxolitinib (INCB018424) and crossresistance to the JAK2 inhibitors AZD1480, CYT-387 and lestaurtinib. In contrast, these resistant variants were fully sensitive to fedratinib. Structural modeling, coupled with mutagenesis and biochemical studies, revealed dual binding sites for fedratinib. In vitro binding assays using purified proteins showed strong affinity for the substrate-binding site (K d = 20 nM) while affinity for the ATP site was poor (K d = ~8 μM). Our studies demonstrate that mutations affecting the substratebinding pocket encode a catalytically incompetent kinase, thereby preventing emergence of resistant variants. Most importantly, our data suggest that in order to develop resistance-free kinase inhibitors, the next-generation drug design should target the substrate-binding site. Myeloproliferative neoplasms (MPNs) are a group of hematologic malignancies that include Ph + chronic myeloid leukemia (CML) and Ph − diseases that includes primary myelofibrosis (MF), polycythemia vera (PV), and essential thrombocythemia (ET). The discovery that constitutive ABL kinase activity is sufficient and necessary to cause CML laid the foundation for development of imatinib as a target-directed therapy 1,2. The clinical success of BCR-ABL inhibitors for the treatment of CML not only revolutionized the anti-kinase therapy but also enforced the idea to identify the genetic lesions in other neoplastic diseases for therapeutic targeting 2-4. In 2005, four groups reported kinase-activating mutations in JAK2 (JAK2-V617F) from BCR-ABL-negative MPN patients 5-8. This discovery generated great interest in treating MPNs by targeting JAK2 with small-molecule kinase inhibitors. JAK2 is a cytosolic tyrosine kinase activated by cytokine-mediated receptor dimerization, resulting in phosphorylation of STATs required for cell proliferation, survival and myeloid development, as well as for the initial stages of the immune response 9. Constitutive JAK2 signaling has been implicated in many other cancers-such as myeloid malignancies, breast cancers and B-cell leukemias 10 and lymphomas 11. This provides a strong rationale for JAK2 targeting, and suggests that the resultant therapies would have broad therapeutic potential. As proof of concept, JAK2-V617F was expressed in mouse hematopoietic cells, generating a tractable mouse model of PV and MF 12-14. In each of these disease models, treatment with small-molecule JAK2-kinase inhibitors induced apoptotic cell death and prolonged the survival of mice 13,15-17. Collectively, these observations paved the way for clinical development of JAK2-targeted therapeutics.
Journal of Biological Chemistry, 2010
The obligate intracellular parasite, Toxoplasma gondii, modulates host immunity in a variety of highly specific ways. Previous work revealed a polymorphic, injected parasite factor, ROP16, to be a key virulence determinant and regulator of host cell transcription. These properties were shown to be partially mediated by dysregulation of the host transcription factors STAT3 and STAT6, but the molecular mechanisms underlying this phenotype were unclear. Here, we use a Type I Toxoplasma strain deficient in ROP16 to show that ROP16 induces not only sustained activation but also an extremely rapid (within 1 min) initial activation of STAT6. Using recombinant wild-type and kinase-deficient ROP16, we demonstrate in vitro that ROP16 has intrinsic tyrosine kinase activity and is capable of directly phosphorylating the key tyrosine residue for STAT6 activation, Tyr 641. Furthermore, ROP16 co-immunoprecipitates with STAT6 from infected cells. Taken together, these data strongly suggest that STAT6 is a direct substrate for ROP16 in vivo.
Proteomimetics of Natural Regulators of JAK–STAT Pathway: Novel Therapeutic Perspectives
Frontiers in Molecular Biosciences
The JAK-STAT pathway is a crucial cellular signaling cascade, including an intricate network of Protein–protein interactions (PPIs) responsible for its regulation. It mediates the activities of several cytokines, interferons, and growth factors and transduces extracellular signals into transcriptional programs to regulate cell growth and differentiation. It is essential for the development and function of both innate and adaptive immunities, and its aberrant deregulation was highlighted in neuroinflammatory diseases and in crucial mechanisms for tumor cell recognition and tumor-induced immune escape. For its involvement in a multitude of biological processes, it can be considered a valuable target for the development of drugs even if a specific focus on possible side effects associated with its inhibition is required. Herein, we review the possibilities to target JAK–STAT by focusing on its natural inhibitors as the suppressor of cytokine signaling (SOCS) proteins. This protein fami...
PloS one, 2018
Lactoferrin (LF), a member of the transferrin family, recently has been demonstrated to have anticancer effects on various cancers including oral squamous cell carcinoma (OSCC). However, little is known about the underlying mechanisms of its effects on OSCC. Therefore, we aimed to investigate the mechanism of the suppressive effects of bovine LF (bLF) on the growth of OSCC cells. In the current study, HSC2, HSC3, HSC4 and normal human oral keratinocytes (RT7) cell lines were tested with bLF 1, 10, and 100 μg/ml. The effects and detail mechanisms of bLF on proliferation and apoptosis of cells were investigated using flow cytometry and western blotting. We found that bLF (1, 10, and 100 μg/ml) induced activation of p53, a tumor suppressor gene, is associated with the induction of cell cycle arrest in G1/S phase and apoptosis in OSCC. Moreover, bLF downregulated the phosphorylation of Akt and activated suppressor of cytokine signaling 3 (SOCS3), thereby attenuating multiple signaling p...
Janus kinase inhibitors role in bone remodeling
Journal of Cellular Physiology, 2019
Janus kinases (JAKs) play a pleiotropic role in several important physiological processes, such as cell maturation, cell proliferation, and cell death, via providing transmission signals from several molecules, such as cytokines, interferons, hormones, and growth factors, to the nucleus. Bone physiology and remodeling are markedly influenced by proinflammatory cytokines. Among them, interleukin-1 (IL-1) and IL-6 are considered potent stimulator of bone resorption. Several cytokine receptors, such as IL-6 receptors, are characterized by tyrosine kinases of the JAK family associated with their intracellular domains. There is an emerging interest in the effects of JAKs inhibition on the cells involved in bone remodeling. JAK inhibitors represent a new class of molecules involved in the therapy of numerous immunemediated inflammatory diseases. In this review, we want to focus on the role of JAKs inhibitors on bone remodeling and on RANKL-RANK-OPG signal and inflammatory cytokines which are involved in the regulation of bone cells, such as osteoblasts and osteoclasts.
Molecular oncology, 2016
Suppressor of cytokine signaling (SOCS) proteins are negative feedback regulators of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. Dysregulation of SOCS protein expression in cancers can be one of the mechanisms that maintain STAT activation, but this mechanism is still poorly understood in oral squamous cell carcinoma (OSCC). Here, we report that SOCS2 protein is significantly downregulated in OSCC patients and its levels are inversely correlated with miR-424-5p expression. We identified the SOCS2 protein, which modulates STAT5 activity, as a direct target of miR-424-5p. The miR-424-5p-induced STAT5 phosphorylation, matrix metalloproteinases (MMPs) expression, and cell migration and invasion were blocked by SOCS2 restoration, suggesting that miR-424-5p exhibits its oncogenic activity through negatively regulating SOCS2 levels. Furthermore, miR-424-5p expression could be induced by the cytokine IL-8 primarily through enhancing STAT5 transcript...
Clinical and Vaccine Immunology, 2013
The suppressor of cytokine signaling 1 (SOCS1) has emerged as a critical inhibitory molecule for controlling the cytokine response and antigen presentation by dendritic cells (DCs), thereby regulating the magnitude of both innate and adaptive immunity. The aim of this study was to investigate whether the SOCS1 antagonist pJAK2(1001-1013) peptide can weaken or block the inhibition function of SOCS1 in DCs by evaluating the phenotype and cytokine production, antigen-presenting, and specific T-cell-activating capacities of DCs electroporated with human gastric cancer cell total RNA. Furthermore, STAT1 activation of the JAK/STAT signal pathway mediated by SOCS1 was analyzed by Western blotting. The results demonstrate that the SOCS1 antagonist pJAK2(1001-1013) peptide upregulated the expression of the maturation marker (CD83) and costimulatory molecule (CD86) of RNA-electroporated human monocyte-derived mature DCs (mDCs), potentiated the capacity of mDCs to induce T-cell proliferation, ...
Pharmaceuticals
Systemic sclerosis and systemic lupus erythematosus represent two distinct autoimmune diseases belonging to the group of connective tissue disorders. Despite the great progress in the basic science, this progress has not been translated to the development of novel therapeutic approaches that can radically change the face of these diseases. The discovery of JAK kinases, which are tyrosine kinases coupled with cytokine receptors, may open a new chapter in the treatment of so far untreatable diseases. Small synthetic compounds that can block Janus kinases and interact directly with cytokine signalling may provide therapeutic potential in these diseases. In this review, we discuss the therapeutic potential of Jak kinases in light of the cytokine network that JAK kinases are able to interact with. We also provide the theoretical background for the rationale of blocking cytokines with specific JAK inhibitors.
Regulation of cGAS‐Mediated Immune Responses and Immunotherapy
Advanced Science, 2020
have confirmed the retinoic acid-inducible gene I (RIG-I)/melanoma differentiationassociated gene 5 (MDA5)-mitochondrial antiviral-signaling protein (MAVS) axis and the cGAS-stimulator of interferon genes (STING) axis as key nucleic acid recognition pathways. Nevertheless, the proper function of immunostimulatory exogenous nucleic acids in cytosolic sensing remains unclear. [3] In addition, aberrant detection of selfnucleic acids, mainly double-stranded deoxyribose nucleic acids (dsDNAs), can predict the outcome in devastating illnesses. [4] Besides, the overactivation of this critical immune pathway contributes to the outcome in autoinflammation and autoimmune disease progression. [5] cGAS-STING-mediated antiviral cellular response initiates downstream signaling pathways, which stimulate TANK binding kinase 1 [TBK1, an IKK (IκB kinase)-related kinase]. Subsequently, TBK1 plays a significant role in regulating innate immunity and activating type I interferon (IFN) regulatory factor 3 (IRF3). [6] IRF3 is essential for the transcription of immune responsive genes, comprising IFN, and immunemodulatory cytokines. [3] The products of these genes cooperatively suppress the proliferation of a broad range of viral entities, such as herpes simplex virus type 1 (HSV1), Kaposi's sarcoma-associated herpesvirus (KSHV), hepatitis C virus (HCV), and Murine gammaherpesvirus 68 (MHV68).
Frontiers in Immunology, 2017
Suppressor of cytokine signaling (SOCS) proteins are major negative feedback regulators of cytokine signaling mediated by the Janus kinase (JAK)-signal transducer and activator of transcription signaling pathway. In particular, SOCS1 and SOCS3 are strong inhibitors of JAKs and can play pivotal roles in the development and progression of cancers. The abnormal expression of SOCS1 and SOCS3 in cancer cells is associated with the dysregulation of cell growth, migration, and death induced by multiple cytokines and hormones in human carcinomas. In addition, the mechanisms involved in SOCS1-and SOCS3-regulated abnormal development and activation of immune cells in carcinogenesis, including T cells, macrophages, dendritic cells, and myeloidderived suppressor cells, are still unclear. Therefore, this study aims to further discuss the molecules and signal pathways regulating the expression and function of SOCS1 and SOCS3 in various types of cancers and elucidate the feasibility and efficiency of SOCS-based target therapeutic strategy in anticancer treatment.
IFN-λ4 Attenuates Antiviral Responses by Enhancing Negative Regulation of IFN Signaling
Journal of immunology (Baltimore, Md. : 1950), 2017
Type III IFNs are important mediators of antiviral immunity. IFN-λ4 is a unique type III IFN because it is produced only in individuals who carry a dG allele of a genetic variant rs368234815-dG/TT. Counterintuitively, those individuals who can produce IFN-λ4, an antiviral cytokine, are also less likely to clear hepatitis C virus infection. In this study, we searched for unique functional properties of IFN-λ4 that might explain its negative effect on hepatitis C virus clearance. We used fresh primary human hepatocytes (PHHs) treated with recombinant type III IFNs or infected with Sendai virus to model acute viral infection and subsequently validated our findings in HepG2 cell line models. Endogenous IFN-λ4 protein was detectable only in Sendai virus-infected PHHs from individuals with the dG allele, where it was poorly secreted but highly functional, even at concentrations < 50 pg/ml. IFN-λ4 acted faster than other type III IFNs in inducing antiviral genes, as well as negative reg...
Drosophila Jak/STAT Signaling: Regulation and Relevance in Human Cancer and Metastasis
International Journal of Molecular Sciences, 2018
Over the past three-decades, Janus kinase (Jak) and signal transducer and activator of transcription (STAT) signaling has emerged as a paradigm to understand the involvement of signal transduction in development and disease pathology. At the molecular level, cytokines and interleukins steer Jak/STAT signaling to transcriptional regulation of target genes, which are involved in cell differentiation, migration, and proliferation. Jak/STAT signaling is involved in various types of blood cell disorders and cancers in humans, and its activation is associated with carcinomas that are more invasive or likely to become metastatic. Despite immense information regarding Jak/STAT regulation, the signaling network has numerous missing links, which is slowing the progress towards developing drug therapies. In mammals, many components act in this cascade, with substantial cross-talk with other signaling pathways. In Drosophila, there are fewer pathway components, which has enabled significant dis...
Glia, 2015
Interleukin-6 (IL-6) participates in the host response to injury and infection in the central nervous system (CNS). We identified strawberry notch homolog 2 (Sbno2) as an IL-6-stimulated gene in murine astrocytes. Sbno2 is a mouse homolog of the sno gene in Drosophila but little is known about the regulation or function of the mammalian gene. Here we examined the regulation of the Sbno2 gene in astrocytes in vitro and in the murine CNS following systemic endotoxin administration. In murine and human cultured astrocytes, Sbno2 gene expression was significantly upregulated in a dose- and time-dependent fashion by hyper-IL-6 (IL-6 + soluble IL-6 receptor). The level of Sbno2 mRNA was also upregulated significantly in murine astrocytes by other glycoprotein130 cytokine-family members and the pro-inflammatory cytokines interleukin-1 beta and tumor necrosis factor alpha. These changes were reflected by corresponding alterations in the level of the SBNO2 protein. Inhibiting protein synthes...
Arthritis & Rheumatology, 2014
Objective. To examine the impact of the gp130 cytokine family on murine articular cartilage and to explore a potential regulatory role of suppressor of cytokine signaling 3 (SOCS-3) in murine chondrocytes. Methods. In wild-type (WT) mouse chondrocytes, baseline receptor expression levels and gp130 cytokineinduced JAK/STAT signaling were determined by flow cytometry, and expression of SOCS-3 was assessed by quantitative polymerase chain reaction. The role of endogenous SOCS-3 was examined in cartilage explants and chondrocytes from mice with conditional deletion of Socs3 driven by the Col2a1 promoter in vitro (Socs3 ⌬/⌬col2) and from mice during CD4؉ T cell-dependent inflammatory monarthritis. Bone erosions in the murine joints were analyzed by micro-computed tomography. Results. On chondrocytes from WT mice, gp130 and the oncostatin M (OSM) receptor were strongly expressed, whereas the transmembrane interleukin-6 (IL-6) receptor was expressed at much lower levels. Compared to other gp130 cytokines, OSM was the most potent activator of the JAK/STAT pathway and of SOCS-3 induction. Treatment of Socs3 ⌬/⌬col2 mouse cartilage explants and chondrocytes with gp130 cytokines prolonged JAK/STAT signaling, enhanced cartilage degradation, increased the expression of Adamts4, Adamts5, and RANKL, and elevated the production of IL-6, granulocyte colony-stimulating factor, CXCL1, and CCL2. Socs3 ⌬/⌬col2 mice developed exacerbated inflammation and joint damage in response to gp130 cytokine injections, and these histopathologic features were also observed in mice with inflammatory monarthritis. Conclusion. The results of this study highlight a key role for SOCS-3 in regulating chondrocyte responses during inflammatory arthritis. Within the gp130 cytokine family, OSM is a potent stimulus of chondrocyte responses, while IL-6 probably signals via trans-signaling. The gp130 cytokine-driven production of RANKL in chondrocytes may link chondrocyte activation and bone remodeling during inflammatory arthritis. Thus, these findings suggest that the inhibition of OSM might reduce the development and severity of structural joint damage during inflammatory arthritis.
Animals
Cereals are often contaminated with fumonisins, which are the toxic byproducts of mold. The aim of the study was to determine the effect of maternal exposure to fumonisins on the development and the liver function of the offspring at weaning. Two doses of fumonisins (60 and 90 mg/kg b.w.) were tested. The changes in the basal blood morphology, the biochemical parameters, the absolute and relative weights of the vital organs, and the changes in the cardiac and biceps brachii muscle histology were studied. The liver damage was assessed by evaluating the liver morphology and the common clinical liver panel. Maternal fumonisin intoxication caused a decrease in the body weight at birth and an increase in the heart, liver, kidney, lungs, ovaries, and testes weights. The cytokines and hormones, as well as the red blood cell counts and hemoglobin levels, were elevated in a dose-dependent manner following the exposure to fumonisins. Maternal exposure caused degenerative morphological and str...
Interleukin 24: Signal Transduction Pathways
Cancers
Interleukin 24 is a member of the IL-10 family with crucial roles in antitumor, wound healing responses, host defense, immune regulation, and inflammation. Interleukin 24 is produced by both immune and nonimmune cells. Its canonical pathway relies on recognition and interaction with specific Interleukin 20 receptors in the plasma membrane and subsequent cytoplasmic Janus protein tyrosine kinases (JAK)/signal transducer and activator of the transcription (STAT) activation. The identification of noncanonical JAK/STAT-independent signaling pathways downstream of IL-24 relies on the interaction of IL-24 with protein kinase R in the cytosol, respiratory chain proteins in the inner mitochondrial membrane, and chaperones such as Sigma 1 Receptor in the endoplasmic reticulum. Numerous studies have shown that enhancing or inhibiting the expression of Interleukin 24 has a therapeutic effect in animal models and clinical trials in different pathologies. Successful drug targeting will require a...
Inferring gene and protein interactions using PubMed citations and consensus Bayesian networks
PloS one, 2017
The PubMed database offers an extensive set of publication data that can be useful, yet inherently complex to use without automated computational techniques. Data repositories such as the Genomic Data Commons (GDC) and the Gene Expression Omnibus (GEO) offer experimental data storage and retrieval as well as curated gene expression profiles. Genetic interaction databases, including Reactome and Ingenuity Pathway Analysis, offer pathway and experiment data analysis using data curated from these publications and data repositories. We have created a method to generate and analyze consensus networks, inferring potential gene interactions, using large numbers of Bayesian networks generated by data mining publications in the PubMed database. Through the concept of network resolution, these consensus networks can be tailored to represent possible genetic interactions. We designed a set of experiments to confirm that our method is stable across variation in both sample and topological input...
Defective JAK-STAT Pathway Signaling Contributes to Autoimmune Diseases
Current Pharmacology Reports, 2018
Purpose of Review Here, we systematically review the published literature indicating that aberrant regulation of Janus kinase/ signal transducers and activators of transcription (JAK-STAT) signaling was associated with the autoimmune disorders, rheumatoid arthritis, systemic lupus erythematosus, psoriasis/psoriatic arthritis, multiple sclerosis, inflammatory bowel diseases, and ankylosing spondylitis. Pertinent Findings The autoimmune disorders discussed in this review are characterized by several alterations resulting in abnormal JAK-STAT signaling. These abnormalities in JAK-STAT signaling include (1) constitutive activation of both the interleukin-6(IL-6)/interleukin-6 receptor (IL-6R) canonical and IL-6 trans-signaling pathway, the latter involving soluble IL-6R; (2) the hyperactivation of JAK/STAT signaling as a response to the significantly elevated levels of pro-inflammatory Bimmunocytokines^, exemplified by IL-6, IL-15, IL-17, IL-23, interferon-γ; and (3) the reduced activity of the negative regulators of JAK-STAT signaling, including suppressor of cytokine signaling and protein inhibitor of activated STATs as well as protein tyrosine phosphatases-1,-2, which was shown to inhibit STAT-signaling. Summary The involvement of abnormal JAK-STAT signaling in autoimmune disorders has led to the development of JAK small molecule inhibitors (SMIs), such as tofacitinib, ruxolitinib, and baricitinib for the therapy of rheumatoid arthritis, psoriasis/ psoriatic arthritis, and Crohn's disease. However, the extent to which treatment of these diseases with JAK SMIs will result in blunting the Bcross-talk^between the JAK-STAT signaling pathway and the other signaling pathways known to participate in autoimmune disorders remains to be determined, involving the mitogen-activated protein kinase pathway and the phosphatidylinositide/Akt/mechanistic target of rapamycin signaling pathway.
Epigenomics
The COVID-19 outbreak has created disaster globally, and mankind is yet to come in terms with combating this global menace. Amid this turmoil, immunocompromised individuals like cancer patients exhibit dismal immune responses toward such infection. In order to treat cancer patients during such adverse situations, it is necessary to understand the phenomena that interlink these two diseased states. Modulation of host epigenetic landscape is a key hallmark of both cancer and viral infections, including COVID-19. Our review aims to shed light upon the interplay between COVID-19 and cancer, primarily through the genetic and epigenetic modulations of the gene expression profile, so as to design better therapeutic strategies in the near future.
Frontiers in Immunology, 2019
Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract disease in children <2 years of age. Increased morbidity and mortality have been reported in high-risk patients, such as premature infants, patients with cardiac disease, and severely immune compromised patients. Severe disease is associated with the virulence of the virus as well as host factors specifically including the innate immune response. The role of type I interferons (IFNs) in the response to RSV infection is important in regulating the rate of virus clearance and in directing the character of the immune response, which is normally associated with protection and less severe disease. Two RSV non-structural proteins, NS1 and NS2, as well as the envelope G glycoprotein are known to suppress type I IFN production and a robust type I IFN response to RSV does not occur in human infants or neonatal mouse models of RSV infection. Additionally, presence of type I IFNs are associated with mild symptoms in infants and administration of IFN-α prior to infection of neonatal mice with RSV reduces immunopathology. This evidence has driven RSV prophylaxis and therapeutic efforts to consider strategies for enhancing type I IFN production.