SKL-2841, a dual antagonist of MCP-1 and MIP-1 beta, prevents bleomycin-induced skin sclerosis in mice

Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrosis and excessive collagen deposition in the skin and various internal organs. In early stages of SSc, the dermis reveals infiltration of inflammatory cells associated with increased collagen synthesis. SKL-2841 was initially synthesized as a novel small molecule antagonist of MCP-1. In this study, we indicated that SKL-2841 also exerts anti-chemotactic activity for MIP-1 beta in mouse spleen cells. In the early stages of bleomycin-induced skin lesions, immunohistochemical analysis showed the expression of both MCP-1 and MIP-1 beta in dermal inflammatory cells. Moreover, intraperitoneal administration of SKL-2841 suppressed the infiltration of inflammatory mononuclear cells and polymorphonuclear cells in the acute phase and also significantly suppressed fibrillization in the chronic phase in bleomycin-induced scleroderma, compared with PBS treatment. These findings suggest that SKL-2841 has potential as a compound for the treatment of conditions associated with skin fibrosis such as SSc.