Study On The Mechanisms And Therapeutic Role Of Endothelial TRPV4-Nox2 Complex On Obesity-induced Vascular Dysfunction

In recent years,cardiovascular disease has increasingly threatened human health.The China Cardiovascular Health and Disease Report shows that there are cumulatively over 300million people with cardiovascular disease in China and the mortality rate remains high.Cardiovascular disease seriously threatens human health.Obesity is an important risk factor for CVD.2018,a study involving 190,000 obese patients published on the JAMA Cardiol showed that obesity leads to earlier onset of cardiovascular disease,increased morbidity,and increased mortality compared to normal people.In 2020,a study in Nat Rev Cardiol revealed that endothelial cells act as regulators of vascular function in response to blood flow shear.Previous studies have indicated that obesity-induced increases in ROS and inflammatory factor production can lead to altered blood flow shear.Transient receptor potential vanilloid type 4（TRPV4）channels were first identified in2000.In recent years,several studies have shown that TRPV4 is an important mechanosensitive channel that can be activated by flow shear to induce calcium influx.Previous studies have shown that the production of ROS,inflammatory factors,relaxing factors,and VE-cadherin in endothelial cells are regulated by calcium signals.It is well known that these vasoactive factors are important for the regulation of vascular function.Nicotinamide adenine dinucleotide phosphate oxidase 2（Nox2）was first identified in 1964.Since then,several studies have shown that Nox2 has an important role in regulating the production of ROS.And studies have shown that Nox2 play a regulatory role in vascular function in response to Ca²⁺signals.Recently,as research has progressed,more and more studies have indicated that protein complexes play an important role in the regulation of vascular function.The findings are supported by articles published in circulation research in 2008 and 2009.At the same time,the research in our group confirms the findings too.Based on these researches,the present study raises the following questions:Does TRPV4on endothelial cells can form a complex with Nox2?Does obesity-induced vascular dysfunction is caused by the altering strength of endothelial TRPV4-Nox2 complex coupling?Is the endothelial TRPV4-Nox2 complex a promising drug target for the protection of vascular function?To answer these questions,a series of experiments were carried.The results were showed as below.1.ROS and inflammatory factor production,endothelial and vascular permeability were increased in endothelial cells in obese mice.At the same time,the vasodilatory function was impaired in obese mice.2.Endothelial TRPV4 and Nox2 were identified to be involved in the regulation of ROS and inflammatory factor production,endothelial and vascular permeability,and involved in the regulation of vasodilatory function in obese mice.At the same time,and obesity was found to enhance the coupling strength of the endothelial TRPV4-Nox2 complex.3.The endothelial TRPV4-Nox2 complex binding site was identified.At the same time,we confirmed that decreasing the physical interaction between endothelial TRPV4-Nox2complex could exert a modulatory effect on obesity-induced vascular dysfunction.4.M12,a small molecule targeting the TRPV4-Nox2 complex in endothelial cells,was found to have a protective effect on vascular function by decreasing the physical interaction between endothelial TRPV4-Nox2 complex.