Fibrogenesis failure of type V collagen observed in pulmonary and cutaneous fibroblast culture reinforce the pathogenic participation of this collagen in the pathway of systemic sclerosis

Abstract

Introduction: Unusual type V collagen (COLV) accumulation was demonstrated in systemic sclerosis (SSc) by our group. In this regard, this study analyzed tridimensional reconstruction (3D), biochemical and molecular profile of COLVα1 and COLVα2 chains in pulmonary and cutaneous fibroblasts culture from patients with SSc. Materials and Methods: Pulmonary and cutaneous fibroblasts for culture were obtained from 7 patients with SSc and from six controls respectively. COLV 3D reconstruction was performed by confocal microscopy. COLVα1 and COLVα2 gene expression was performed by RT-PCR and COLV protein expression by immunoblotting. Results: COL V 3D reconstruction showed distorted and strongly thickened fibers with irregular bundles resulting in a dense network in lung and skin fibroblast cultures from SSc patients compared to the thin fibers from fibroblast controls. Collagen quantification showed significant increased COLV fiber expression in SSc cutaneous and pulmonary fibroblasts (P<0.01) compared with the respective controls. In the same way, molecular evaluation demonstrated an increased significance (P=0.05) of COLVα1 and COLVα2 mRNA expression in cutaneous and pulmonary fibroblasts from SSc patients to that of control groups. The immunoblotting analysis demonstrated the increased weight of the molecular COLV chains. Conclusion: COLV overexpression and an unusual organization of these fibers including molecular and biochemical changes, suggest an interference process of the COLV fibrillogenesis in patients with SSc, reinforcing the participation of this collagen in SSc pathogenesis and open new therapeutic perspectives for these patients.