Role of Janus Kinase 3 in Mucosal Differentiation and Predisposition to Colitis (original) (raw)
Related papers
Mucosal Epithelial Jak Kinases in Health and Diseases
Mediators of Inflammation, 2021
Janus kinases (Jaks) are a family of nonreceptor tyrosine kinase that include four different members, viz., Jak1, Jak2, Jak3, and Tyk2. Jaks play critical roles in immune cells functions; however, recent studies suggest they also play essential roles in nonimmune cell physiology. This review highlights the significance of epithelial Jaks in understanding the molecular basis of some of the diseases through regulation of epithelial-mesenchymal transition, cell survival, cell growth, development, and differentiation. Growth factors and cytokines produced by the cells of hematopoietic origin use Jak kinases for signal transduction in both immune and nonimmune cells. Among Jaks, Jak3 is widely expressed in both immune cells and in intestinal epithelial cells (IECs) of both humans and mice. Mutations that abrogate Jak3 functions cause an autosomal severe combined immunodeficiency disease (SCID) while activating Jak3 mutations lead to the development of hematologic and epithelial cancers. ...
V617F‐independent upregulation of JAK2 gene expression in patients with inflammatory bowel disease
Journal of Cellular Biochemistry, 2019
Background: Inflammatory bowel disease (IBD) is one of the most important immune-mediated disorders of the gastrointestinal tract. Besides, IBD is associated with numerous extraintestinal complications such as venous thromboembolism (VTE), an important risk factor for vascular complications, which results in the increased morbidity and mortality. The JAK2 (Janus kinase 2) V617F mutation is a well-known point mutation which is involved in the pathogenesis of IBD, and VTE. Therefore, the aims of this study were to evaluate expression of JAK2 and association of V617F mutation in JAK2 of Iranian patients with IBD. Methods: Two hundred and forty-six patients with IBD (209 UC and 37 CD) and 206 healthy controls were enrolled in this study. The genomic DNA and total RNA were extracted from peripheral blood mononuclear cells (PBMCs). Then, the JAK2 V617F mutation detection was performed using the restriction fragment length polymorphism (RFLP) method. In addition, the JAK2 mRNA expression was evaluated using a quantitative polymerase chain reaction (q-PCR) using the SYBR Green assay. Results: There was no association of V61F mutation in patients with IBD with or without thrombosis compared with healthy control. However, the relative mRNA expression of JAK2 was significantly upregulated in patients with IBD in
Mucosal immunology, 2017
c-Jun N-terminal kinases (JNKs) contribute to immune signaling but their functional role during intestinal mucosal inflammation has remained ill defined. Using genetic mouse models, we characterized the role of JNK1 and JNK2 during homeostasis and acute colitis. Epithelial apoptosis, regeneration, differentiation, and barrier function were analyzed in intestinal epithelium-specific (ΔIEC) or complete JNK1 and bone marrow chimeric or complete JNK2 deficient mice as well as double-knockout animals (JNK1(ΔIEC)JNK2(-/-)) during homeostasis and acute dextran sulfate sodium (DSS)-induced colitis. Results were confirmed using human HT-29 cells and wild-type or JNK2-deficient mouse intestinal organoid cultures. We show that nonhematopoietic JNK2 but not JNK1 expression confers protection from DSS-induced intestinal inflammation reducing epithelial barrier dysfunction and enterocyte apoptosis. JNK2 additionally enhanced Atonal homolog 1 expression, goblet cell and enteroendocrine cell differ...
Journal of Crohn's and Colitis, 2017
shorter in EP4 cKO mice relative to control mice. Apoptosis and cell proliferation were markedly increased within the crypts in EP4 cKO mice. In terms of differentiation, secretary lineages including goblet cells, tuft cells, and entero-endocrine cells were significantly decreased in EP4 cKO mice. Furthermore, ectopic Paneth cells were observed in EP4 cKO colons, whereas they were not observed in controls. Moreover, colonic epithelial cells expressing Muc2 and Cdx2 were markedly decreased in EP4 cKO mice. Notably, instead of decreased number of cells expressing Muc2 and Cdx2, colonic epithelial cells expressing Notch1IC, Hes1 and Sox9 were significantly increased and distribution of these cells was extended from the bottom to the more upper regions of the crypts in EP4 cKO mice, suggesting that Notch signaling was more broadly activated in EP4 cKO mice. Additionally, in a DSS-colitis model, colitis was more severely exacerbated in EP4 cKO mice. Conclusions: Intestinal EP4 receptor is required for homeostasis of the colon in mice, which appears to be mediated by Notch signaling pathway.
JAK1 inhibition and inflammatory bowel disease
Rheumatology
Primary non-response and secondary loss of response remain a significant issue with the currently available treatment options for a significant proportion of patients with inflammatory bowel disease (IBD). There are multiple unmet needs in the IBD treatment algorithm and new treatment options are required. As our understanding of the pathogenesis of IBD evolves, new therapeutic targets are being identified. The JAK-STAT pathway has been extensively studied. Tofacitinib, a JAK1 inhibitor, is now licensed for use in the induction and maintenance of ulcerative colitis and there are a large number of molecules currently under investigation. These new small molecule drugs (SMDs) will challenge current treatment pathways at a time when clinical therapeutic outcomes are rapidly evolving and becoming more ambitious. This is a review of the current JAK1 inhibitors in IBD including the current evidence from clinical trials. CME: This supplement is CME Accredited. To receive a CME certificate ...
World Journal of Gastroenterology, 2020
In 2018, the pan-Janus kinase (JAK) inhibitor tofacitinib was launched for the treatment of ulcerative colitis (UC). Although tofacitinib has proven efficacious in patients with active UC, it failed in patients with Crohn's disease (CD). This finding strongly hints at a different contribution of JAK signaling in both entities. Here, we review the current knowledge on the interplay between the JAK/signal transducer and activator of transcription (STAT) pathway and inflammatory bowel diseases (IBD). In particular, we provide a detailed overview of the differences and similarities of JAK/STAT-signaling in UC and CD, highlight the impact of the JAK/STAT pathway in experimental colitis models and summarize the published evidence on JAK/STAT-signaling in immune cells of IBD as well as the genetic association between the JAK/STAT pathway and IBD. Finally, we describe novel treatment strategies targeting JAK/STAT inhibition in UC and CD and comment on the limitations and challenges of the new drug class.
Journal of inflammation (London, England), 2017
An unmet need remains for safe and effective treatments to induce and maintain remission in inflammatory bowel disease (IBD) patients. The Janus kinase (JAK) inhibitor, tofacitinib, has demonstrated robust efficacy in ulcerative colitis patients although, like other systemic immunosuppressants, there may be safety concerns associated with its use. This preclinical study evaluated whether modulating intestinal inflammation via local JAK inhibition can provide efficacy without systemic immunosuppression. The influence of tofacitinib, dosed orally or intracecally, on oxazolone-induced colitis, oxazolone or interferon-γ (IFNγ)-induced elevation of colonic phosphorylated signal transducer and activator of transcription1 (pSTAT1) levels, and basal splenic natural killer (NK) cell counts was investigated in mice. Tofacitinib, dosed orally or intracecally, inhibited, with similar efficacy, oxazolone-induced colitis, represented by improvements in the disease activity index and its sub-score...
Journal of Inflammation Research, 2013
The c-Jun N-terminal kinases (JNKs) are involved in signal transduction of inflammatory bowel diseases. The aim of this study was to examine the function of JNKs by using a low-dose dextran sulfate sodium (DSS) model in JNK1 knockout mice (Mapk8-/-), JNK2 knockout mice (Mapk9-/-), and wild-type controls (WT1, WT2). Methods: The animals were evaluated daily using a disease activity index. After 30 days, the intestine was evaluated histologically with a crypt damage score. CD4+ and CD8+ cells were quantified using immunofluorescence. Analysis of tumor necrosis factor-α (TNFα), interleukin-6 (IL-6), and transforming growth factor β1 (TGFB1) expression was carried out using LightCycler ® real-time polymerase chain reaction. Results: Cyclic administration of low-dose DSS (1%) was not able to induce features of chronic colitis in Mapk8-/-WT2 mice. By contrast, DSS administration significantly increased the disease activity index in WT1 and Mapk9-/-mice. In Mapk9-/-mice, the crypt damage score and the number of CD4+ and CD8+ cells as features of chronic colitis/inflammation were also significantly elevated. Expression of TNFα, IL-6, and TGFB1 was not altered by the JNK knockout. Conclusion: Administering DSS at a defined low concentration that is unable to induce colitis in WT animals leads to clinically and histologically detectable chronic colitis in Mapk9-/mice. The reason for this disease-inducing effect resulting from the loss of JNK2 remains to be elucidated. Expression of TNFα, IL-6, and TGFB1 does not appear to be involved; proapoptotic JNK2 may prolong the activity of proinflammatory immune cells, leading to perpetuation of the inflammation.
Protein kinases are potential targets to treat inflammatory bowel disease
World journal of gastrointestinal pharmacology and therapeutics, 2014
Protein kinases play a crucial role in the pathogenesis of inflammatory bowel disease (IBD), the two main forms of which are ulcerative colitis and Crohn's disease. In this article, we will review the mechanisms of involvement of protein kinases in the pathogenesis of and intervention against IBD, in terms of their effects on genetics, microbiota, mucous layer and tight junction, and the potential of protein kinases as therapeutic targets against IBD.