Inhibition of discoidin domain receptors by imatinib prevented pancreatic fibrosis demonstrated in experimental chronic pancreatitis model (original) (raw)
Related papers
2020
Discoidin domain receptors (DDR1 and DDR2) are the collagen receptors of the family tyrosine kinases, which play signi cant role in the diseases like in ammation, brosis and cancer. Chronic pancreatitis (CP) is a bro-in ammatory disease in which recurrent pancreatic in ammation leads to pancreatic brosis. Methods: In the present study for the rst time, we have investigated the role of DDR1 and DDR2 in cerulein-induced CP. Pancreatic DDR1 and DDR2 expression was examined by immunoblotting and immunostaining analysis. Subsequently, the protective effects of selective DDR1 and DDR2 inhibitor, imatinib (IMT) was investigated in CP mice as a therapeutic intervention. Results: Activated pancreatic stellate cells (PSCs) and CP mice showed signi cant upregulation of DDR1 and DDR2 expression. Pharmacological intervention with IMT effectively downregulated DDR1 and DDR2 expression. Further, we found that pancreatic injury, in ammation, extracellular matrix (ECM) deposition and PSCs activation were signi cantly inhibited by IMT. Further, we found a signi cant inhibition of TGF-β1/Smad signaling pathway by IMT and showed its protective effects against CP and associated brosis. Conclusions: Taken together, these results suggest that inhibition of DDR1 and DDR2 controls pancreatic in ammation and brosis, which could represent an attractive and promising therapeutic strategy for the treatment of CP.
Molecular Cancer Therapeutics, 2017
The extracellular matrix (ECM), a principal component of pancreatic ductal adenocarcinoma (PDA), is rich in fibrillar collagens that facilitate tumor cell survival and chemoresistance. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that specifically binds fibrillar collagens and has been implicated in promoting cell proliferation, migration, adhesion, ECM remodeling, and response to growth factors. We found that collagen-induced activation of DDR1 stimulated protumorigenic signaling through protein tyrosine kinase 2 (PYK2) and pseudopodium-enriched atypical kinase 1 (PEAK1) in pancreatic cancer cells. Pharmacologic inhibition of DDR1 with an ATP-competitive orally available small-molecule kinase inhibitor (7rh) abrogated collagen-induced DDR1 signaling in pancreatic tumor cells and consequently reduced colony formation and migration. Furthermore, the inhibition of DDR1 with 7rh showed striking efficacy in combination with chemotherapy in orthotopic xenografts and a...
Disordered Pancreatic Inflammatory Responses and Inhibition of Fibrosis in CD39-Null Mice
Gastroenterology, 2008
Background & Aims-Extracellular nucleotides are released from injured cells and bind to purinergic-type 2 receptors (P2-R) that modulate inflammatory responses. Ectonucleotidases, such as CD39/NTPDase1, hydrolyze extracellular nucleotides to integrate purinergic signaling responses. As the role of extracellular nucleotides and CD39 in mediating inflammation and fibrosis are poorly understood, we studied the impact of CD39 gene deletion in a model of pancreatic disease.
Digestive Diseases and Sciences, 2019
Background and Aims-Chronic pancreatitis is associated with recurrent inflammation, pain, fibrosis, and loss of exocrine and endocrine pancreatic function and risk of cancer. We hypothesized that activation of the CCK receptor contributes to pancreatitis and blockade of this pathway would improve chronic pancreatitis. Methods-Two murine models were used to determine whether CCK receptor blockade with proglumide could prevent and reverse histologic and biochemical features of chronic pancreatitis: the 6-week repetitive chronic cerulein injection model and the modified 75% choline-deficient ethionine (CDE) diet. In the CDE-fed model, half the mice received water supplemented with proglumide, for 18 weeks. After chronic pancreatitis was established in the cerulein model, half the mice were treated with proglumide and half with water. Histology was scored in a blinded fashion for inflammation, fibrosis and acinar ductal metaplasia (ADM) and serum lipase levels were measured. RNA was extracted and examined for differentially expressed fibrosis genes. Results-Proglumide therapy decreased pancreatic weight in the CDE diet study and the cerulein-induced chronic pancreatitis model. Fibrosis, inflammation, and ADM scores were significantly reduced in both models. Lipase values improved with proglumide but not in controls in both models. Proglumide decreased pancreas mRNA expression of amylase, collagen-4, and TGFβR2 gene expression by 44, 38, and 25%, respectively, compared to control mice. Conclusion-New strategies are needed to decreased inflammation and reduce fibrosis in chronic pancreatitis. CCK receptor antagonist therapy may improve chronic pancreatitis by ✉
PLoS ONE, 2013
Pancreatic fibrosis, a prominent histopathological feature of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma, is essentially a dynamic process that leads to irreversible scarring of parenchymal tissues of the pancreas. Though the exact mechanisms of its initiation and development are poorly understood, recent studies suggested that the activation of pancreatic stellate cells (PSCs) plays a critical role in eliciting such active course of fibrogenesis. Anthraquinone compounds possess anti-inflammatory bioactivities whereas its natural derivative rhein has been shown to effectively reduce tissue edema and free-radical production in rat models of inflammatory conditions. Apart from its anti-inflammatory properties, rhein actually exerts strong anti-fibrotic effects in our current in-vivo and in-vitro experiments. In the mouse model of cerulein-induced CP, prolonged administration of rhein at 50 mg/kg/day significantly decreased immunoreactivities of the principal fibrotic activators alpha-smooth muscle actin (α-SMA) and transforming growth factor-beta (TGF-β) on pancreatic sections implicating the activation of PSCs, which is the central tread to fibrogenesis, was attenuated. Consequently, the overwhelmed deposition of extracellular matrix proteins fibronectin 1 (FN1) and type I collagen (COL I-α1) in exocrine parenchyma was found accordingly reduced. In addition, the expression levels of sonic hedgehog (SHH), which plays important roles in molecular modulation of various fibrotic processes, and its immediate effector GLI1 in pancreatic tissues were positively correlated to the degree of cerulein-induced fibrosis. Such up-regulation of SHH signaling was restrained in rhein-treated CP mice. In cultured PSCs, we demonstrated that the expression levels of TGF-β-stimulated fibrogenic markers including α-SMA, FN1 and COL I-α1 as well as SHH were all notably suppressed by the application of rhein at 10 μM. The present study firstly reported that rhein attenuates PSC activation and suppresses SHH/GLI1 signaling in pancreatic fibrosis. With strong anti-fibrotic effects provided, rhein can be a potential remedy for fibrotic and/or PSC-related pathologies in the pancreas. .hk PLOS ONE | www.plosone.org 1 December 2013 | Volume 8 | Issue 12 | e82201 experimental groups were subjected to standard H&E staining. Abnormal architecture, glandular atrophy and inflammatory cell infiltrates were evaluated from the H&E sections. Magnification 200 ×. (B) By means of Western blotting analyses, the expression levels of α-SMA and FN1 in pancreatic homogenates were examined. (C) Integrated densities of the immunobands of α-SMA and FN1 were measured, normalized to the loading reference β-ACTIN and calculated as fold changes over the Control group. Readings were taken from 4 individual blots. (D) Synthesis of collagen I-α1 mRNA and protein was determined by means of qPCR and Sirius Red staining respectively. Collagen proteins were stained with Sirius Red whereas non-collagenous proteins were stained with Fast Green. Color was eluted from the tissue sections and measured at 540 nm and 640 nm. * p< 0.05 when comparing to the Control group whereas Φp< 0.05 when comparing to the Cerulein group. (E) In paraffin-embedded pancreatic tissues, the activated PSCs were stained green (FITC) with α-SMA-antibody whereas nuclei were stained blue with DAPI. Magnification 200 ×. (F) Images enlarged from (E) using the SPOT Advanced program for a more detailed view of the activated PSCs. (G) mRNA expression levels of Acta2 and Tgf-β in pancreatic tissues were determined by means of qPCR using SYBR Green reagent, normalized to the internal reference Gapdh and expressed as fold changes over the Control group. * p< 0.05 when comparing to the Control group whereas Φ p< 0.05 when comparing to the Cerulein group.
Bone Morphogenetic Protein Signaling Protects against Cerulein-Induced Pancreatic Fibrosis
PLoS ONE, 2014
Bone morphogenetic proteins (BMPs) have an anti-fibrogenic function in the kidney, lung, and liver. However, their role in chronic pancreatitis (CP) is unknown. The aim of this study was to define the anti-fibrogenic role of BMP signaling in the pancreas in vivo under CP induction. Mice with a deletion of BMP type II receptor (BMPR2 +/2) were used in this study in comparison with wild-type mice. CP was induced by repetitive cerulein injection intraperitoneally for 4 weeks, and the severity of CP was evaluated. Pancreatic stellate cells (PSCs) were isolated from the mice and treated with BMP2 and TGF-b in vitro, and extracellular matrix protein (ECM) production was measured. Smad and mitogen-activated protein kinase (MAPK) signaling was also evaluated. BMPR2 +/2 mice revealed a greater pancreatic fibrosis, PSC activation and leukocyte infiltration after CP induction compared to wild-type mice (P,0.05). Under CP induction, phospho (p)Smad1/5/8 was elevated in wildtype mice and this effect was abolished in BMPR2 +/2 mice; pSmad2 and pp38 MAPK were further enhanced in BMPR2 +/2 mice compared to wild-type mice (P,0.05). In vitro, BMP2 inhibited TGF-b-induced ECM protein fibronectin production in wildtype PSCs; this effect was abolished in BMPR2 +/2 PSCs (P,0.05). In BMPR2 +/2 PSCs, pSmad1/5/8 level was barely detectable upon BMP2 stimulation, while pSmad2 level was further enhanced by TGF-b stimulation, compared to wild-type PSCs (P, 0.05). BMPR2/Smad1/5/8 signaling plays a protective role against cerulein-induced pancreatic fibrosis by inhibiting Smad2 and p38 MAPK signaling pathways.
American Journal of Physiology-Gastrointestinal and Liver Physiology, 2001
The pancreas morphology of transgenic mice that overexpress transforming growth factor-β1 (TGF-β1) in the pancreas resembles partially morphological features of chronic pancreatitis, such as progressive accumulation of extracellular matrix (ECM). Using this transgenic mouse model, we characterized the composition of pancreatic fibrosis and involved fibrogenic mediators. On day 14 after birth, fibrotic tissue was mainly composed of collagen type I and III. At this time, mRNA levels of TGF-β1 were increased. On day 70, the ECM composition was expanded by increased deposition of fibronectin, whereas connective tissue growth factor, fibroblast growth factor (FGF)-1, and FGF-2 mRNA expression levels were elevated in addition to TGF-β1. In parallel, the number of pancreatic stellate cells (PSC) increased over time. In vitro, TGF-β1 stimulated collagen type I expression but not fibronectin expression in PSC, in contrast to FGF-2, which stimulated both. This confirms that TGF-β1 mediates pa...
BET inhibitors block pancreatic stellate cell collagen I production and attenuate fibrosis in vivo
JCI insight, 2017
The fibrotic reaction, which can account for over 70%-80% of the tumor mass, is a characteristic feature of human pancreatic ductal adenocarcinoma (PDAC) tumors. It is associated with activation and proliferation of pancreatic stellate cells (PSCs), which are key regulators of collagen I production and fibrosis in vivo. In this report, we show that members of the bromodomain and extraterminal (BET) family of proteins are expressed in primary PSCs isolated from human PDAC tumors, with BRD4 positively regulating, and BRD2 and BRD3 negatively regulating, collagen I expression in primary cancer-associated PSCs. We show that the inhibitory effect of pan-BET inhibitors on collagen I expression in primary cancer-associated PSCs is through blocking of BRD4 function. Importantly, we show that FOSL1 is repressed by BRD4 in primary cancer-associated PSCs and negatively regulates collagen I expression. While BET inhibitors do not affect viability or induce PSC apoptosis or senescence, BET inhib...