Analysis of synthesis and hystoarquiteture of extracellular matrix and cell signaling proteins in fibroblasts stimulated with collagen v and in systemic sclerosis

• Grant number: 16/25658-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2017
• End date: December 10, 2018
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Walcy Paganelli Rosolia Teodoro
• Grantee: Isadora Begalli Mendes
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Fibrosis is the main feature of chronic connective tissue disease known as systemic sclerosis or scleroderma (SSc). This is characterized by proliferative vasculopathy, immune reactivity and fibrosis of the skin and some internal organs; being the excessive deposition of collagen in the extracellular matrix the most striking feature in SSc pathogenesis. Most authors justify cutaneous and pulmonary remodelling in these patients, due to the intense synthesis of collagen I (COLI) and collagen III (COLIII) during ES evolution. However, recent studies by our group have shown that in the early stages of the disease, skin and lungs exhibit distortion of their fibrillary pattern, increased collagen synthesis V (COLV), and gene expression of the COLV alpha chains, being these parameters related to disease activity. The COLV differs from other types of fibrillary collagen due to its important functions in fibrilogenesis and nucleation of heterotypic collagen I / III / V fibrils. Previous studies in the SSc experimental model, induced by immunization of healthy rabbits with COLV, showed vascular and immune changes, fibrosis in the skin and internal organs, similar to the disease in humans. It is believed that the COLV may be related to the activation of fibroblasts in SSc patients, through mechanisms of cellular signalling of proteins involved in fibrosis and that cutaneous and pulmonary involvement may be related to a post-translational alteration in the COLV synthesis and / or their chains. On the other hand, the interaction of the matrix cell also depends on several soluble factors, such as cytokines and growth factors; matricellular proteins such as Secreted Protein Acid and Rich in Cystein (SPARC); as well as cell receptors, such as integrins and Discoidin Domain Receptor (DDR) receptors. Among the cytokines and growth factors, TGF-² stands out in the physiopathology of SSc, due to its importance in the activation of fibroblasts, which culminates in the fibrotic process of several organs. Some studies suggest that fibroblasts from SSc patients are more sensitive to TGF-² than normal fibroblasts and it is also suggested that there is greater expression of their SSc receptors. All these factors interfere in the quality and quantity of ECM produced by fibroblasts under normal physiological conditions as well as in fibrotic pathological processes. Considering that COL V regulates the fibrilogenesis of collagens I and III; yet, COL V has increased synthesis in SSc and its increase is related to the activity of the disease, our proposal in this study is to evaluate the gene expression of the SPARC protein and the DDR2 receptor in fibroblasts of healthy individuals, stimulated with type V collagen and compare with the expression of these markers on fibroblasts and skin of SSc patients. Furthermore, since TGF-², integrins and ±-smooth muscle actin (±-SMA) are altered in SSc, our proposal will be to analyse the gene expression of these proteins in cutaneous fibroblasts of healthy individuals stimulated with collagen type V. (AU)