IRF7 and STAT1 gene expression profile in peripheral blood mononuclear cells of patients with systemic sclerosis

The critical role of IFN signature genes has increasingly been surveyed to determine the etiology and pathogenesis of systemic sclerosis (SSc). Interferon-regulatory factors (IRFs) and signal transducers and activators of transcription (STATs) are mainly considered as transcriptional modulators of IFN-signature genes and type I interferon and play a major role in the regulation of numerous aspects of an immune response. The current study aimed to assess the transcriptional levels of IRF7 (interferon-regulatory factor 7) and STAT1 (signal transducers and activators of transcription 1) mRNAs in PBMCs of scleroderma patients and compare them with those of healthy subjects. In this study, PBMCs were obtained from 50 scleroderma patients and 30 healthy individuals. Subsequently, total RNA was extracted from isolated PBMCs and cDNA synthesis was carried out. IRF7 and STAT1 mRNA expressions were assessed by applying quantitative real-time PCR, SYBR Green method, and specific primers for IRF7 and STAT1. Relative expression of IRF7 was significantly increased in the patient group compared with the control group. Moreover, relative expression of IRF7 in limited SSc (lSSc) and diffuse SSc (dSSc) was significantly increased compared with healthy subjects (p < 0.05). The relative expression of STAT1 transcripts in PBMCs was not statistically significantly different between the patient group and the control group. The correlation between IRF7 expression and the Rodnan score (RS) of the disease was significant. Considering the overexpression of IRF7 in SSc patients and significant correlation between the IRF7 and the Rodnan score of the disease, it is suggested that impaired expression of IRF7 is involved in the pathogenesis of SSc.