Endothelial cells that line the entire vascular system play a pivotal role in the control of various physiological processes, including metabolism. Additionally, endothelial dysfunction is associated with many pathological conditions, including obesity. Here, we assessed the role of the BBSome, a protein complex composed of eight Bardet-Biedl syndrome (BBS) proteins in endothelial cells. We studied the effects of BBSome disruption in endothelial cells on vascular function, body weight, glucose homeostasis, and the liver and retina. For this, we generated mice with selective BBSome disruption in endothelial cells through Bbs1 gene deletion. We found that endothelial cell-specific BBSome disruption causes endothelial dysfunction, as indicated by the impaired acetylcholine-induced vasorelaxation in both the aorta and mesenteric artery. This was associated with an increase in the contractile response to thromboxane A2 receptor agonist (U46619) in the mesenteric artery. Mechanistically, we demonstrated that mice lacking the Bbs1 gene in endothelial cells show elevated vascular angiotensinogen gene expression, implicating renin-angiotensin system activation in the vascular changes evoked by endothelial BBSome deficiency. Strikingly, our data indicate that endothelial BBSome deficiency increases body weight and fat mass and causes hepatosteatosis along with alterations in hepatic expression of lipid metabolism-related genes and metabolomics profile. In addition, electroretinogram and optical coherence tomography analyses revealed functional and structural abnormalities in the retina, evoked by absence of the endothelial BBSome. Our findings demonstrate that the BBSome in endothelial cells is required for the regulation of vascular function, adiposity, hepatic lipid metabolism, and retinal function.

Human serum albumin (HSA) is the most abundant protein in plasma, and the redox state of circulating HSA has been used as a biomarker of systemic oxidative stress (OS) for decades. While informative, many traditional biomarkers of OS measure short-lived or downstream products of oxidative damage that offer limited perspectives on the dynamic and integrated processes that govern systemic redox biology within human populations. By moving beyond single-analyte damage markers and towards coordinated patterns of protein modifications, HSA-Cys³⁴ adductomics offers a systems-level approach that simultaneously captures change in multiple layers of OS. Because of its high abundance in plasma and HSA’s unique and highly reactive single free thiol (Cys³⁴), HSA-Cys³⁴ serves as an ideal sentinel target for monitoring reactions with reactive oxygen species (ROS), reactive nitrogen species (RNS), and electrophilic species produced by endogenous metabolism and responses to exogenous chemical exposures. The reaction of HSA with ROS, RNS, and reactive electrophiles yields a diverse array of protein modifications, including direct oxidation products (sulfenic, sulfinic, and sulfonic acid), low molecular weight thiol-disulfide exchange, and lipid peroxidation (LPO)-derived reactive aldehydes. With a mean residence time of about a month, these accumulated adducts serve as an integrated picture of oxidative and electrophilic stress that together function as a molecular record of systemic redox physiology. Previous studies using high-resolution mass spectrometry-based adductomics have enabled global untargeted analysis of HSA-Cys³⁴ modifications, yielding an expansive inventory of novel redox signatures of environmental stressors and disease states. In this paper we review the chemistry and biology underlying OS-related modifications of HSA-Cys³⁴ and highlight the important role of HSA-Cys³⁴ adducts as integrative biomarkers of OS at the interface of molecular biology, exposure assessment, and public health research.