Elucidating the molecular mechanisms of smoking-induced endothelial dysfunction associated with ALDH2*2 - Project Summary Smoking remains a leading cause of cardiovascular disease (CVD), responsible for millions of deaths worldwide. Despite its widespread impact, the precise mechanisms linking smoking to CVD risk, particularly in relation to genetic factors, remain incompletely understood. One such genetic variation, ALDH2*2, affects approximately 540 million individuals globally and may interact with tobacco smoke to exacerbate CVD risk. However, the addictive nature of smoking, compounded by social and cultural influences, complicates efforts to reduce smoking prevalence in this population. Consequently, understanding the role of ALDH2*2 in smoking-induced CVD is crucial for advancing precision medicine for individuals affected by this genetic variation. Our previous research, which utilized induced pluripotent stem cell (iPSC)-derived endothelial cells (iPSC-ECs) from individuals carrying the ALDH2*2 variant, revealed significant endothelial dysfunction. These cells demonstrated elevated oxidative stress and inflammation, along with reduced nitric oxide production and tube formation capacity (Guo et al., Science Translational Medicine, 2023). Our recent findings further suggest that the endothelial dysfunction associated with the ALDH2*2 variant is exacerbated by exposure to cigarette smoke in both human iPSC and transgenic mouse models. Despite these findings, the specific mechanisms by which tobacco consumption exacerbates CVD risk in individuals with the ALDH2*2 variant remain unclear, impeding the development of tailored approaches for ALDH2*2 smokers. The overarching goal of our proposal is to utilize a multidisciplinary approach that integrates stem cell biology, molecular biology, toxicology, vascular physiology, and endothelial mechanobiology to elucidate the molecular mechanisms underlying ALDH2*2- and smoking- induced endothelial dysfunction. We will pursue two specific aims. In Aim 1, we will examine the ROS-FOXO1- KLF5→IL-18/IL-1β signaling axis in modulating endothelial dysfunction in both human iPSC and mouse models carrying the ALDH2*2 variant. Additionally, we will screen small molecules targeting the ROS-FOXO1-KLF5 axis in cigarette smoke-exposed ALDH2*2 iPSC-ECs to evaluate their effects on endothelial function. In Aim 2, we will examine NUP210’s interaction with the LINC complex in mediating the shear stress response in ALDH2*2- and smoking-induced endothelial dysfunction. We will utilize RNA-seq, ATAC-seq, ChIP-seq, and single-cell RNA-seq to gain mechanistic insights into how NUP210 interacts with LINC complex and regulates the H3K27me3 modification of extracellular matrix genes in response to mechanical forces. Our proposal is supported by robust preliminary data, and the successful completion of this research will identify two novel molecular mechanisms—KLF5-mediated inflammation and NUP210-mediated shear stress response—through which smoking exacerbates CVD risk in the ALDH2*2 carriers. Additionally, the study will provide insights into potential prognostic biomarkers and therapeutic targets to mitigate CVD in smokers with the ALDH2*2 allele.
