Project description:As an endothelium destabilizer, CD82 facilitates vascular leakage by disrupting endothelial barrier and inhibiting its recovery during inflammation. AC at EC surface primes and promotes vascular leakage, mediates the effect of CD82 or TEMD on inflammation, and can be regulated specifically by i) tetraspanins or TEMDs, ii) ORP-mediated transfer of cholesterol, iii) environmental cholesterol, and iv) statin. Thus, tetraspanin-AC interaction and subcellular cholesterol compartmentalization tune the balances between antagonistic signaling axes of Cdc42 versus RhoA, to alter vascular leakage in inflammation. Equally important, we demonstrated anti-vascular leakage and anti-inflammation roles of i) AC reduction and ii) FARP1-Cdc42 elevation/activation in animal models, with promising translational and clinical prospects.
2025-06-19 | PXD065001 | Pride
Project description:Cholesterol accessibility at the ciliary membrane controls hedgehog signaling
Project description:The Aster-C protein (encoded by the Gramd1c gene) is an endoplasmic reticulum (ER) resident protein that has been reported to transport cholesterol from the plasma membrane to the ER . Although there is a clear role for the closely-related Aster-B protein in cholesterol transport and downstream esterification in the adrenal gland, the specific role for Aster-C in tissue cholesterol homeostasis is not well understood. Here, we have examined whole body cholesterol balance in mice globally lacking Aster-C under low or high dietary cholesterol conditions.transport and metabolism under divergent dietary cholesterol conditions. These results strongly suggest that Aster-C alone is not sufficient to control whole body cholesterol balance, but can modestly impact circulating cortisol and bile acid levels when dietary cholesterol is limited.
Project description:We report the chromatin accessibility of rat vascular smooth muscle cell at de-differentiated state (induced by DAPT treatment), inflammatory state (induced by cholesterol treatment) and macrophage-like state (induced by combined treatment of DAPT and cholesterol)
Project description:Regulation of endothelial nutrient transport is poorly understood. Vascular endothelial growth factor (VEGF)-B signaling in endothelial cells promotes uptake and transcytosis of fatty acids (FA) from the bloodstream to the underlying tissue, advancing pathological lipid accumulation and lipotoxicity in diabetic complications. Here we demonstrate a VEGF-B dependent obstruction of endothelial glucose transport attributed to plasma membrane lipid alterations affecting glucose transporter 1 function, which was independent of FA uptake. Specifically, VEGF-B signaling impaired recycling of low-density lipoprotein receptor to the plasma membrane, leading to reduced cholesterol uptake and membrane cholesterol loading, decreasing endothelial glucose uptake capacity. Inhibiting VEGF-B in vivo was accordingly linked to reconstitution of membrane cholesterol and induction of glucose uptake, of particular relevance for conditions inferring insulin resistance and diabetic complications. In summary, our study reveals a novel mechanism of action for VEGF-B in endothelial nutrient uptake and highlights the impact of membrane cholesterol for the regulation of endothelial glucose transport.
Project description:Regulation of endothelial nutrient transport is poorly understood. Vascular endothelial growth factor (VEGF)-B signaling in endothelial cells promotes uptake and transcytosis of fatty acids (FA) from the bloodstream to the underlying tissue, advancing pathological lipid accumulation and lipotoxicity in diabetic complications. Here we demonstrate a VEGF-B dependent obstruction of endothelial glucose transport attributed to plasma membrane lipid alterations affecting glucose transporter 1 function, which was independent of FA uptake. Specifically, VEGF-B signaling impaired recycling of low-density lipoprotein receptor to the plasma membrane, leading to reduced cholesterol uptake and membrane cholesterol loading, decreasing endothelial glucose uptake capacity. Inhibiting VEGF-B in vivo was accordingly linked to reconstitution of membrane cholesterol and induction of glucose uptake, of particular relevance for conditions inferring insulin resistance and diabetic complications. In summary, our study reveals a novel mechanism of action for VEGF-B in endothelial nutrient uptake and highlights the impact of membrane cholesterol for the regulation of endothelial glucose transport.
Project description:A small dose of the anti-HIV drug efavirenz (EFV) was previously discovered to activate CYP46A1, a cholesterol-eliminating enzyme in the brain, and mitigate some of the manifestation of Alzheimer’s disease in 5XFAD mice. Herein, we investigated the retina of these animals, which were found to have genetically determined retinal vascular lesions associated with deposits within the retinal pigment epithelium and subretinal space. We established that EFV treatment activated CYP46A1 in the retina, enhanced retinal cholesterol turnover, and diminished the lesion frequency >5-fold. In addition, the treatment mitigated fluorescein leakage from the aberrant blood vessels, deposit size, activation of retinal macrophages/microglia, and focal accumulations of amyloid b plaques, unesterified cholesterol, and Oil Red O-positive lipids. Studies of retinal transcriptomics and proteomics identified biological processes enriched with differentially expressed genes and proteins. We discuss the mechanisms of the beneficial EFV effects on the retinal phenotype of 5XFAD mice. As EFV is an FDA-approved drug, and we already tested the safety of small-dose EFV in patients with Alzheimer’s disease, our data support further clinical investigation of this drug in subjects with retinal vascular lesions or neovascular age-related macular degeneration.
Project description:We have previously reported that the dengue virus (DENV) type 3 P12/08 strain caused a lethal systemic infection, severe vascular leakage at terminal stage in IFN-α/β and γ receptors knockout mice (IFN-α/β/γRKO mice), and blockade of TNF-α signaling drastically protected mice. However, the detailed pathological mechanism remains unknown. Therefore, we performed transcriptome analysis of liver and intestinal specimens, which showed most clearly exhibited vascular leakage, chronologically collected from infected- IFN-α/β/γRKO mice with/without anti-TNF-α Ab treatment.
Project description:The goal was to investigate whether the induction of gene expression by vascular endothelial growth factor (VEGF) in endothelial cells depends on endosomal GTPases Rab5A or Rab5C.