Vascular cell glycocalyx-mediated vascular remodeling induced by hemodynamic environmental alteration

Vascular remodeling induced by hemodynamic stimuli contributes to the pathophysiology of cardiovascular diseases. The importance of vascular cells (endothelial cells and smooth muscle cells) glycocalyx in the mechanotransduction of flow-induced shear stress at the cellular and molecular levels has been demonstrated over the past decade. However, its potential mechanotransduction role in vascular remodeling has triggered little attention. In the present study, a homemade apparatus was used to expose the rat abdominal aorta to sterile, flow or no flow, normal-pressure or high-pressure conditions for 4 days. The histomophometric, cellular, and molecular analysis of vessels were performed. The results showed that after exposing the vessels in the flow and high-pressure condition, the apoptotic rate, the cell number, and the RNA level of contractile marker gene smooth muscle 22 of smooth muscle cells were significantly increased, whereas the expression of nitric oxide synthase, α-smooth muscle actin, smoothelin, and calponion showed no significant differences compared with the flow and normal-pressure groups. Moreover, the histomophometric analysis of vascular walls suggested a remodeling induced by flow and high-pressure loading consistent with the classic hypertensive aortic phenotype, which is characterized by a thicker and more rigid vascular wall as well as increased aortic diameter. However, those phenomena were totally abolished after compromising the integrity of glycocalyx by the treatment of vessels with hyaluronidase, which provided evidence of the important mechanotransduction role of the vascular cells glycocalyx in vascular remodeling induced by hemodynamic stimuli.