Systemic sclerosis (SSc) is an autoimmune disorder of unknown origin, characterized by excess accumulation of the extracellular matrix in the skin and other internal organs.
Aim of the work
The current study was designed to establish an animal model of SSc in order to analyze the histological and immunohistochemical changes in the skin and lungs as well as to try to find a possible pathophysiologic mechanism for this disease by studying the gene expression of some fibrogenic genes.
Materials and methods
Twenty adult male albino rats were included in this study. They were divided into two groups: the control group (10) and the bleomycin-treated group (10). Histological examination including H&E staining and Masson’s trichrome staining for skin and lung tissue samples and immunohistochemical examination for measuring α-SMA were performed. RNA was extracted from these tissue samples and semiquantitative Rt-PCR for α-SMA, transforming growth factor β (TGF-β), and TNF-α was performed.
Histological changes were observed in SSc, including collagen deposition and increased expression of α-SMA in both skin and lung tissues, with increased dermal thickness in the skin. Moreover, overexpression of α-SMA, TGF-β, and TNF-α in skin and lung tissues of the SSc group was observed.
Male rat model is a good model for SSc. α-SMA, TGF-β, and TNF-α could play a role in the pathophysiologic mechanism of SSc, as they showed overexpression in both skin and lung tissues that correlate with the histological and immunohistochemical findings of the disease.