Regulation of F2RL3/PAR4 Expression and Function by Methylat

Smoking causes cardiovascular disease, which is a leading cause of death in the United States with more than 61 million Americans suffering from some form of cardiovascular disease. The total costs for medical care for people with adverse health effects caused by smoking is extraordinary in the tens of billions of dollars according to health economists at the University of California. Both tobacco-smoking and e-cigarettes generate toxins, which enter the blood stream and directly contribute to the development of cardiovascular disease. Smoke-products are believed to cause changes in the genetic material of blood cells. In fact, the development of recent technologies has allowed investigators to examine genetic changes (called methylation) in blood cells caused by smoking in thousands of people in seventeen different studies performed in the United States and Europe. This work has led to discovery of a gene called F2RL3 that is mostly frequently modified in smokers compared to non-smokers and is strongly correlated with an increased risk of cardiovascular disease and cardiovascular-related mortality. The F2RL3 gene encodes a protein called protease-activated receptor-4 (PAR4). PAR4 is expressed in several blood cells including platelets (important for thrombosis, also knowns as blood clotting) and neutrophils important for inflammation. Thrombosis and inflammation are key processes that contribute to cardiovascular disease. Despite the substantial evidence that smoking directly modulates F2RL3 methylation, there have been no studies that have examined whether this F2RL3 methylation has an effect on PAR4 expression or function. PAR4 is an important receptor for the clotting factor thrombin and is expressed on platelets. In addition, PAR4 is expressed on inflammatory cells called neutrophils and is important for neutrophil function. The focus of this proposal is to determine whether smoke products including tobacco-smoke, e-cigarette vapor with or without nicotine cause changes in F2RL3 methylation resulting in modulation of either PAR4 expression and function that may promote cardiovascular disease. The studies proposed in the high impact pilot research award will provide for the first time important new information about how F2RL3 may contribute to cardiovascular disease and thereby advance F2RL3 status as a new biomarker for adverse health effects associated with smoking as well as provide to a better understanding of the underlying mechanism that increase the risk of smoking-related diseases, which is poorly understood.