Potential effects of matrix metalloproteinase (MMP)-2 on the sarcoplasmic reticulum calcium ATPase (SERCA) in Hypertension-induced vascular dysfunction

• Grant number: 20/02619-1
• Support type: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): August 01, 2020
• Effective date (End): July 31, 2023
• Field of knowledge: Biological Sciences - Pharmacology - Cardiorenal Pharmacology
• Principal researcher: Michele Mazzaron de Castro
• Grantee: Marcela Maria Blascke de Mello
• Home Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Matrix metalloproteinase (MMP)-2 degrades intracellular proteins that regulate the contraction of Vascular Smooth Muscle Cells (VSMCs), like calponin-1, and it is more active in rats two kidneys-one clip (2K-1C), being responsible for cell proliferation and arterial remodeling. The sarcoplasmic reticulum Ca2+-ATPase (SERCA) controls the concentration of calcium in the cytosol of VSMCs, whose increase can activate the Nuclear Factor of Activated T cells (NFAT), resulting in cell proliferation and vasoconstriction. In hypertension, SERCA generally shows reduced activity. It was seen that during cardiac ischemia and reperfusion, the increased activity of MMP-2 contributes to SERCA proteolysis. The objective is to investigate whether MMP-2 is responsible for SERCA proteolysis in aortas, contributing to vascular morphofunctional changes in hypertension. It will be verified in aortas of Sprague-Dawley rats and knockout NFAT mice (KO), submitted to 2K-1C or fictitious (Sham) surgery. 2K-1C rats will be treated with doxycycline and/or ONO-4817. To verify whether the possible proteolysis of SERCA by MMP-2 in hypertension can result in: 1) accumulation of calcium and vasoconstriction, aortas will be submitted to gel and in situ zymography, immunofluorescence (IF) for MMP-2, SERCA and calcium, western blot (WB) for MMP-2 and SERCA, co-immunoprecipitation for MMP-2 and SERCA and vascular reactivity; 2) accumulation of calcium and increased VSMCs proliferation with hypertrophic remodeling, aortas of KO NFAT mice will be subjected to morphofunctional analyzes by histological staining and pressurized myography, immunohistochemistry for cell proliferation and WB for NFAT and D1 cyclin. (AU)