Elafin Reverses Intestinal Fibrosis by Inhibiting Cathepsin S-Mediated Protease-Activated Receptor 2

  • Cell Mol Gastroenterol Hepatol. 2022;14(4):841-876. doi: 10.1016/j.jcmgh.2022.06.011.
Ying Xie  1 Lindsey Fontenot  2 Andrea Chupina Estrada  2 Becca Nelson  2 Jiani Wang  1 David Q Shih  3 Wendy Ho  2 S Anjani Mattai  4 Florian Rieder  5 Dane D Jensen  6 Nigel W Bunnett  7 Hon Wai Koon  8
Affiliations
  • 1. Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California; Department of Gastroenterology, The First Hospital of China Medical University, Shenyang City, Liaoning Province, China.
  • 2. Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California.
  • 3. F. Widjaja Foundation, Inflammatory Bowel & Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.
  • 4. Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California.
  • 5. Department of Gastroenterology, Hepatology, and Nutrition, Digestive Diseases and Surgery Institute, Cleveland Clinic Foundation, Cleveland, Ohio.
  • 6. Bluestone Center for Clinical Research, New York University College of Dentistry, New York, New York.
  • 7. Department of Molecular Pathobiology, Department of Neuroscience and Physiology, Neuroscience Institute, New York University, New York, New York.
  • 8. Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California. Electronic address: [email protected].
Abstract

Background & aims: More than half of Crohn's disease patients develop intestinal fibrosis-induced intestinal strictures. Elafin is a human protease inhibitor that is down-regulated in the stricturing intestine of Crohn's disease patients. We investigated the efficacy of elafin in reversing intestinal fibrosis and elucidated its mechanism of action.

Methods: We developed a new method to mimic a stricturing Crohn's disease environment and induce fibrogenesis using stricturing Crohn's disease patient-derived serum exosomes to condition fresh human intestinal tissues and primary stricturing Crohn's disease patient-derived intestinal fibroblasts. Three mouse models of intestinal fibrosis, including SAMP1/YitFc mice, Salmonella-infected mice, and trinitrobenzene sulfonic acid-treated mice, were also studied. Elafin-Eudragit FS30D formulation and elafin-overexpressing construct and lentivirus were used.

Results: Elafin reversed Collagen synthesis in human intestinal tissues and fibroblasts pretreated with Crohn's disease patient-derived serum exosomes. Proteome arrays identified Cathepsin S as a novel fibroblast-derived pro-fibrogenic protease. Elafin directly suppressed Cathepsin S activity to inhibit Protease-activated Receptor 2 activity and Zinc finger E-box-binding homeobox 1 expression, leading to reduced Collagen expression in intestinal fibroblasts. Elafin overexpression reversed ileal fibrosis in SAMP1/YitFc mice, cecal fibrosis in Salmonella-infected mice, and colonic fibrosis in trinitrobenzene sulfonic acid-treated mice. Cathepsin S, Protease-activated Receptor 2 agonist, and zinc finger E-box-binding homeobox 1 overexpression abolished the anti-fibrogenic effect of elafin in fibroblasts and all 3 mouse models of intestinal fibrosis. Oral elafin-Eudragit FS30D treatment abolished colonic fibrosis in trinitrobenzene sulfonic acid-treated mice.

Conclusions: Elafin suppresses Collagen synthesis in intestinal fibroblasts via Cathepsin S-dependent Protease-activated Receptor 2 inhibition and decreases zinc finger E-box-binding homeobox 1 expression. The reduced Collagen synthesis leads to the reversal of intestinal fibrosis. Thus, modified elafin may be a therapeutic approach for intestinal fibrosis.

Keywords
Fibrosis; Protease; Receptor.
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