Inhibitors of Arg-Gly-Asp-Binding Integrins Reduce Development of Pancreatic Fibrosis in Mice

Abstract

Background & AimsPancreatic stellate cells (PSCs) regulate the development of chronic pancreatitis (CP) and are activated by the cytokine transforming growth factor β (TGFB). Integrins of the αv family promote TGFB signaling in mice, probably by interacting with the Arg-Gly-Asp (RGD) sequence of the TGFB latency-associated peptide, which frees TGFB to bind its cellular receptors. However, little is known about the role of integrins in the development of CP. We investigated the effects of small-molecule integrin inhibitors in a mouse model of CP.MethodsWe induced CP in C57BL/6 female mice by repeated cerulein administration. An active RGD peptidomimetic compound (Center for World Health and Medicine [CWHM]-12) was delivered by continuous infusion, starting 3 days before or 5 days after cerulein administration began. Pancreata were collected and parenchymal atrophy, fibrosis, and activation of PSCs were assessed by histologic, gene, and protein expression analyses. We measured CWHM-12 effects on activation of TGFB in co-culture assays in which rat PSC cells (large T immortalized cells [LTC-14]) activate expression of a TGFB-sensitive promoter in reporter cells.ResultsPancreatic tissues of mice expressed messenger RNAs encoding subunits of RGD-binding integrins. Cerulein administration increased expression of these integrins, altered pancreatic cell morphology, and induced fibrosis. The integrin inhibitor CWHM-12 decreased acinar cell atrophy and loss, and substantially reduced fibrosis, activation of PSCs, and expression of genes regulated by TGFB. CWHM-12 also reduced established fibrosis in mice and blocked activation of TGFB in cultured cells.ConclusionsBased on studies of a mouse model of CP and cultured PSCs, integrins that bind RGD sequences activate PSCs and promote the development of pancreatic fibrogenesis in mice. Small-molecule antagonists of this interaction might be developed for treatment of pancreatic fibrotic diseases.

An Inhibitor of Arginine‐Glycine‐Aspartate‐Binding Integrins Reverses Fibrosis in a Mouse Model of Nonalcoholic Steatohepatitis

“…Because the severity of NASH‐induced liver fibrosis is the main predictor of liver‐related mortality in NASH, it is critically important to identify the mechanisms responsible for fibrosis development in NASH and to develop treatments that are effective in the prevention and reversal of fibrosis. Recently, RGD‐binding integrins were found to play an important role in the development of organ fibrosis, and several studies, including a study from our laboratory, demonstrated the efficacy of a potent small‐molecule synthetic analog of the RGD peptide (CWHM‐12) in mouse‐injury models of liver, lung, muscle, and pancreatic fibrosis . Here, by assessing CWHM‐12 in a mouse model of NASH, we provide evidence supporting the role of RGD‐binding integrins in the pathogenesis of NASH‐induced liver fibrosis.…”

“…CWHM‐12 was delivered by continuous infusion at 100 mg/kg/day (in 50% dimethyl sulfoxide [DMSO], 50% H 2 O) using Alzet mini‐osmotic pumps (Durect, Cupertino, CA) implanted subcutaneously in mice starting at the end of week 6 for the duration of the final 4 weeks. This dosing regimen has been demonstrated to be efficient in reducing fibrosis in other injury models . Minipumps with vehicle (50% DMSO, 50% H 2 O) were implanted in CDAHFD and chow diet control groups.…”

“…Recently, a small molecule integrin antagonist compound, (3S)‐3‐(3‐bromo‐5‐(tert‐butyl)phenyl)‐3‐(2‐(3‐hydroxy‐5‐((5‐hydroxy‐1,4,5,6‐tetrahydropyrimidin‐2‐yl)amino)benzamido)acetamido)propanoic acid (Center for World Health and Medicine [CWHM]‐12), that simultaneously and selectively targets several of the profibrotic integrins was discovered by the CWHM at Saint Louis University. Treatment with this compound was demonstrated to alleviate liver, lung, muscle, and pancreatic fibrosis in mouse injury models . However, the role of RGD‐binding integrins in the development of NASH fibrosis and their pharmacologic inhibition to prevent or reverse NASH fibrosis have not been assessed.…”

RGD-Modified Albumin Nanoconjugates for Targeted Delivery of a Porphyrin Photosensitizer

“…26 As the main transmembrane cell adhesion and signaling receptor proteins, about half of integrin heterodimers connect the cytoskeleton with the extracellular matrix (ECM) via binding to Arginine-Glycine-Aspartic Acid (RGD) sequence. 26, 27 Integrins play pivotal roles in cancer progression, such as proliferation, invasion and metastasis, through binding to ECM components. 28 Some integrins, including αvβ3 and αvβ5, are overexpressed in neovasculature and some tumors including ovarian cancer (OvCa).…”

Chronic Pancreatitis in the 21st Century - Research Challenges and Opportunities

“…Treating mice with the αV integrin inhibitor CWHM-12 both prevented pancreatic fibrosis and reversed established pancreatic fibrosis in the repetitive injury model 31 . An inactive stereoisomer had no effect.…”