Expressão de HLA-G e HLA-G5 em pacientes com síndrome de Parry-Romberg

Abstract

The Parry-Romberg Syndrome (PRS) or Progressive hemifacial atrophy (HFA) is a rare disorder (1:250,000 to 1:700,000), of unknown etiology, characterized by unilateral atrophy of the face, affecting the skin, soft tissues, muscles and bone, in slow, progressive and self-limited form. The pathogenesis of SPR is heterogeneous, seems to be associated with linear scleroderma, but it is not totally understood. Viral infections, trauma, neurological activity and autoimmunity have been proposed to explain the etiology of SPR. Based on the inflammatory mechanism and proposed autoimmune as a cause for SPR and HLA-G gene being involved in some inflammatory and autoimmune diseases, the aim of this study is to verify if the expression levels of the isoforms HLA-G and HLA-G5 differs between patients with SPR and controls. Mesenchymal stem cells derived from adipose tissue (ASCs) were isolated from fat obtained by liposuction from patients (n = 9) prior to use for fat grafting autologous therapeutic purposes, and from controls (n = 9), in this case for aesthetic purposes. Total RNA was isolated from ASCs and quantitative PCR Real time was used to analyse the expression of the isoforms HLA-G (membrane) and HLA-G5 (soluble) of the HLA-G gene. Statistical analysis was performed using the nonparametric test of Mann-Whitney. It was observed that the ASCs from patients with PRS had lower relative expression of HLA-G - membrane isoform (p = 0.000), but not HLA-G5 - soluble isoform (p = 0.387). HLA-G is an immunomodulatory molecule associated with inflammatory and autoimmune diseases, so this study shows for the first time, that low levels of HLA-G expression in patients with SPR may be related to suppression of the immune response, leading to a autoimune. Additional studies verifying the reproducibility of this result are needed to better understand the importance of HLA-G and the molecular mechanisms involved in the etiology of SPR, to improve early diagnosis strategies and open therapeutic perspectives aimed the increasing immunosuppressive activity by stimulating the increase HLA-G expression in these patients.