Behavior of endothelial and muscular cells submitted to shear stress: a cellular and biochemical overview

Author(s)

Anderson Moreira Gomes

• Document type: Master's Dissertation
• Press: Botucatu. 2019-04-29.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2019-02-22
• Advisor: Willian Fernando Zambuzzi

Abstract

Endothelial cells (ECs) and smooth muscle cells (AoSMCs) are the major cellular components of the endothelium. Interactions between these cell types play roles in homeostasis and vascular structure. As an interface between the blood and the vessel wall, ECs occupy a single site directly exposed to shear stress (SS), the mechanical lateral friction force produced by blood flow on the apical membrane of the endothelial cell, which can influence behavior of both ECs and AoSMCs. Generally, AoSMCs do not directly undergo shear forces, however, they are directly exposed to blood flow when vascular injury occurs, for example in some atherosclerotic lesions or by invasive techniques such as angioplasty or surgical endarterectomy. Hemodynamic forces influence the functional properties of the endothelium, but these are not deeply understood as to the biochemical mechanisms of endothelial cell and smooth muscle responses. Thus, the purpose of this dissertation was to establish an in vitro culture model that mimics the shear forces, seeking to understand cellular, biochemical and epigenetic mechanisms. Culture of human endothelial and smooth muscle cells were obtained from the company LONZA and maintained according to the manufacturer's recommendations. These cells were routinely maintained under standard conditions in CO2 incubator. To mimic blood flow, these cells were separately seeded in a peripheral ring of a petri dish (100mm diameter), modified according to previous studies, and maintained under laminar flow for 72 hours, when the cells were collected and sent to the different methodologies. Our results are presented in 2 chapters in this dissertation, with Cap. 2 dedicated to the mechanisms involved in the adaptation of endothelial cells to shear stress, and Cap. 3, dedicated to the mechanisms triggered in smooth muscle cells. Overall, our results show differential responses between endothelial and smooth muscle cells at shear stress, which are governed by epigenetic mechanisms in the control of gene expression triggered by the remodeling of the extracellular matrix, evaluated here as an important mechanism of adaptation of these cells to shear forces. (AU)

• FAPESP's process: 16/22270-8 - Behavior of endothelial and smooth muscular cells under shear-stress model: a panorama of cellular, ultrastructural and biochemistry aspects
• Grantee: Anderson Moreira Gomes
• Support Opportunities: Scholarships in Brazil - Master