The Effect of a Novel Serine Protease Inhibitor on Inflammation and Intestinal Permeability in a Murine Colitis Transfer Model

Hanne Van Spaendonk; Hannah Ceuleers; Annemieke Smet; Maya Berg; Jurgen Joossens; Pieter Van der Veken; Sven M Francque; Anne-Marie Lambeir; Joris G De Man; Ingrid De Meester; Koen Augustyns; Benedicte Y De Winter

doi:10.3389/fphar.2021.682065

The Effect of a Novel Serine Protease Inhibitor on Inflammation and Intestinal Permeability in a Murine Colitis Transfer Model

Front Pharmacol. 2021 Jun 24:12:682065. doi: 10.3389/fphar.2021.682065. eCollection 2021.

Authors

Hanne Van Spaendonk^{1

2}, Hannah Ceuleers^{1

2}, Annemieke Smet^{1

2}, Maya Berg², Jurgen Joossens³, Pieter Van der Veken^{2

3}, Sven M Francque^{1

2

4}, Anne-Marie Lambeir^{2

5}, Joris G De Man^{1

2}, Ingrid De Meester^{2

5}, Koen Augustyns^{2

3}, Benedicte Y De Winter^{1

2

4}

Affiliations

¹ Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Antwerp, Belgium.
² Infla-Med, Centre of Excellence, University of Antwerp, Antwerp, Belgium.
³ Laboratory of Medicinal Chemistry, University of Antwerp, Antwerp, Belgium.
⁴ Division of Gastroenterology and Hepatology, Antwerp University Hospital, Antwerp, Belgium.
⁵ Laboratory of Medical Biochemistry, University of Antwerp, Antwerp, Belgium.

Abstract

Background: A protease/antiprotease disbalance is observed in inflammatory bowel diseases (IBD). We therefore studied the effect of the novel serine protease inhibitor UAMC-00050 on intestinal inflammation and permeability in a chronic colitis T cell transfer mouse model to get further insight into the regulation of T cell-mediated immunopathology. Methods: Colitis was induced in severe combined immunodeficient (SCID) mice, by the adoptive transfer of CD4⁺CD25^-CD62L⁺ T cells. Animals were treated intraperitoneally (i.p.) 2x/day with vehicle or UAMC-00050 (5 mg/kg) from week 2 onwards. Colonic inflammation was assessed by clinical parameters, colonoscopy, macroscopy, microscopy, myeloperoxidase activity and cytokine expression levels. At week 4, 4 kDa FITC-dextran intestinal permeability was evaluated and T helper transcription factors, protease-activated receptors and junctional proteins were quantified by RT-qPCR. Results: Adoptive transfer of CD4⁺CD25^-CD62L⁺ T cells resulted in colonic inflammation and an altered intestinal permeability. The serine protease inhibitor UAMC-00050 ameliorated both the inflammatory parameters and the intestinal barrier function. Furthermore, a decrease in colonic mRNA expression of Tbet and PAR4 was observed in colitis mice after UAMC-00050 treatment. Conclusion: The beneficial effect of UAMC-00050 on inflammation was apparent via a reduction of Tbet, IFN-γ, TNF-α, IL-1β and IL-6. Based on these results, we hypothesize a pivotal effect of serine protease inhibition on the Th1 inflammatory profile potentially mediated via PAR4.

Keywords: T cell transfer colitis mouse model; T cells; intestinal barrier; protease-activated receptors; serine protease inhibitor.