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MKP-1 Deficiency Exacerbates Skin Fibrosis in a Mouse Model of Scleroderma
Morena Scotece1, Mari Hämäläinen1, Tiina Leppänen1
1The Immunopharmacology Research Group, Faculty of Medicine and Health Technology, Tampere University and Tampere University Hospital, 33014 Tampere, Finland.
Abstract:
Scleroderma is a chronic fibrotic disease, where proinflammatory and profibrotic events precede collagen accumulation. MKP-1 [mitogen-activated protein kinase (MAPK) phosphatase-1] downregulates inflammatory MAPK pathways suppressing inflammation. MKP-1 also supports Th1 polarization, which could shift Th1/Th2 balance away from profibrotic Th2 profile prevalent in scleroderma. In the present study, we investigated the potential protective role of MKP-1 in scleroderma. We utilized bleomycin-induced dermal fibrosis model as a well-characterized experimental model of scleroderma. Dermal fibrosis and collagen deposition as well as the expression of inflammatory and profibrotic mediators were analyzed in the skin samples. Bleomycin-induced dermal thickness and lipodystrophy were increased in MKP-1-deficient mice. MKP-1 deficiency enhanced collagen accumulation and increased expression of collagens, 1A1 and 3A1, in the dermis. Bleomycin-treated skin from MKP-1-deficient mice also showed enhanced expression of inflammatory and profibrotic factors IL-6, TGF-β1, fibronectin-1 and YKL-40, and chemokines MCP-1, MIP-1α and MIP-2, as compared to wild-type mice. The results show, for the first time, that MKP-1 protects from bleomycin-induced dermal fibrosis, suggesting that MKP-1 favorably modifies inflammation and fibrotic processes that drive the pathogenesis of scleroderma. Compounds enhancing the expression or activity of MKP-1 could thus prevent fibrotic processes in scleroderma and possess potential as a novel immunomodulative drug.
Insights
Mitogen-activated protein kinase phosphatase-1 (MKP-1) protects against scleroderma by reducing inflammation and fibrosis. MKP-1 deficiency worsens bleomycin-induced dermal fibrosis and collagen accumulation in mice.
Area of Science:
- Immunology
- Dermatology
- Fibrosis Research
Background:
- Scleroderma is a chronic fibrotic disease characterized by inflammation and excessive collagen deposition.
- Mitogen-activated protein kinase phosphatase-1 (MKP-1) is known to suppress inflammatory pathways and influence T-helper cell polarization.
Purpose of the Study:
- To investigate the protective role of MKP-1 in a mouse model of scleroderma.
- To determine if MKP-1 deficiency exacerbates dermal fibrosis and associated inflammatory and profibrotic mediators.
Main Methods:
- Utilized a bleomycin-induced dermal fibrosis model in mice.
- Analyzed skin samples for dermal thickness, lipodystrophy, collagen deposition, and expression of inflammatory and profibrotic mediators.
- Compared outcomes between MKP-1-deficient mice and wild-type mice.
Main Results:
- MKP-1-deficient mice showed increased dermal thickness and lipodystrophy after bleomycin treatment.
- Collagen accumulation and expression of collagens 1A1 and 3A1 were enhanced in MKP-1-deficient mice.
- Expression of inflammatory factors (IL-6, TGF-β1), fibrotic factors (fibronectin-1, YKL-40), and chemokines (MCP-1, MIP-1α, MIP-2) was significantly higher in bleomycin-treated MKP-1-deficient mice.
Conclusions:
- MKP-1 demonstrates a protective effect against bleomycin-induced dermal fibrosis.
- MKP-1 favorably modulates the inflammatory and fibrotic processes central to scleroderma pathogenesis.
- Enhancing MKP-1 expression or activity presents a potential therapeutic strategy for scleroderma treatment.
