Decreased Fibrogenesis After Treatment with Pirfenidone in a Newly Developed Mouse Model of Intestinal Fibrosis

Abstract

BACKGROUND Fibrosis as a common problem in patients with Crohn's disease is a result of an imbalance toward excessive tissue repair. At present, there is no specific treatment option. Pirfenidone is approved for the treatment of idiopathic pulmonary fibrosis with both antifibrotic and anti-inflammatory effects. We subsequently investigated the impact of pirfenidone treatment on development of fibrosis in a new mouse model of intestinal fibrosis. METHODS Small bowel resections from donor mice were transplanted subcutaneously into the neck of recipients. Animals received either pirfenidone (100 mg/kg, three times daily, orally) or vehicle. RESULTS After administration of pirfenidone, a significantly decreased collagen layer thickness was revealed as compared to vehicle (9.7 ± 1.0 versus 13.5 ± 1.5 µm, respectively, **P < 0.001). Transforming growth factor-and matrix metalloproteinase-9 were significantly decreased after treatment with pirfenidone as confirmed by real-time PCR (0.42 ± 0.13 versus 1.00 ± 0.21 and 0.46 ± 0.24 versus 1.00 ± 0.62 mRNA expression level relative to GAPDH, respectively, *P < 0.05). Significantly decreased transforming growth factor-after administration of pirfenidone was confirmed by Western blotting. CONCLUSION In our mouse model, intestinal fibrosis can be reliably induced and is developed within 7 days. Pirfenidone partially prevented the development of fibrosis, making it a potential treatment option against Crohn's disease-associated fibrosis.

Factors Promoting Development of Fibrosis in Crohn’s Disease

“…As the available reagents to study fibrosis in rats are limited and it was desirably to study certain knockout or transgenic animal models we investigated whether the heterotopic transplant model also would work in mice (Figures 1A–C). As expected, we found a similar time course of development of fibrosis in the mouse model (44). C57BL/6 mice are used as donors for isogeneic transplantation into C57BL/6 recipients in this model.…”

“…Interestingly, a rapid revascularization occurs in the intestinal grafts in the neck fold (Figures 1D–F). In small intestinal grafts isolated up to 21 days after transplantation, the lumen was obstructed by granulation tissue and fibrotic material (Figures 1G–J and (44)). The grafts partially had lost their typical crypt structure which in some specimen occurred already at day 2 after transplantation indicating that hypoxia may have an important role for this development.…”

Mechanisms, Management, and Treatment of Fibrosis in Patients With Inflammatory Bowel Diseases

“…The factors that induce fibrosis in this model are certainly different from those of IBD, but this model might be used to study anti-fibrotic agents 43-46 . In a recently developed model, heterotopic transplantation of small bowel tissues 47, 48 leads to rapid fibrosis within 2 weeks, associated with increased intestinal expression of mediators of fibrosis such as αvβ6 integrin, IL13, and TGFB. This model is artificial, but it has been used to test anti-fibrotic agents 47, 49 .…”

“…In a recently developed model, heterotopic transplantation of small bowel tissues 47, 48 leads to rapid fibrosis within 2 weeks, associated with increased intestinal expression of mediators of fibrosis such as αvβ6 integrin, IL13, and TGFB. This model is artificial, but it has been used to test anti-fibrotic agents 47, 49 . None of these models perfectly recapitulate IBD, but they provide an opportunity to define mechanisms and pathways of fibrogenesis and screen therapeutic agents 34 (see Supplemental Table 2) .…”

Crohn’s Strictures—Moving Away from the Knife

“…Three times daily oral doses of pirfenidone commenced at time of transplantation and continued for 7 days reduced TGFβ expression and intestinal fibrosis in an intestinal transplant mouse model (88), suggesting that it may prevent fibrosis in CD. Animal models of intestinal fibrosis will provide an opportunity for preclinical testing of future drugs that target signaling pathways (23, 89), and therapies to reverse as well as prevent fibrosis will be required (35).…”