HMGB1 Induced Oxidative Stress and Inflammation in Endothelial Cells Exposed to Impinging Flow

Abstract

Plain Language SummaryOxidative stress and inflammatory are two important factors that are involved in the formation and development of intracranial aneurysm (IA). Wall shear stress (WSS) produced by impinging flow can induce oxidative stress and inflammatory. However, the specific mechanisms remain unclear. Accumulating evidence has shown that high mobility group box-1 (HMGB1) is associated with oxidative stress-related chronic diseases and inflammatory. We used a modified T-chamber to simulate the in vitro situation of human umbilical vein ECs (HUVECs) subjected to impinging flow at the arterial bifurcation in order to analyze the effect of WSS on HUVECs. The levels of oxidative stress were determined by measuring ROS levels using flow cytometry. The inflammatory was examined using Western blot to measure IL-1β, IL-6, and IL-8 expression levels. Our results demonstrate that WSS can induce oxidative stress and inflammatory in HUVECs. Moreover, we used Western blot to find high expression of HMGB1 in response to impinging flow. We also found by immunofluorescence that HMGB1 undergoes nuclear to cytoplasmic translocation upon exposure to impinging flow. Subsequently, we knocked down HMGB1 using lentiviral transfection of HUVECs and found that the levels of inflammatory and oxidative stress in HUVECs were significantly reduced. This allows us to conclude that HMGB1 is indeed involved in mediating the inflammatory and oxidative stress in HUVECs exposed to WSS. Those findings provide a theoretical basis and a research direction for targeting IA disease through the regulation of oxidative stress and inflammatory response.