Orai–vascular endothelial-cadherin signaling complex regulates high-glucose exposure-induced increased permeability of mouse aortic endothelial cells

Abstract

IntroductionDiabetes-associated endothelial barrier function impairment might be linked to disturbances in Ca2+ homeostasis. To study the role and molecular mechanism of Orais–vascular endothelial (VE)-cadherin signaling complex and its downstream signaling pathway in diabetic endothelial injury using mouse aortic endothelial cells (MAECs).Research design and methodsThe activity of store-operated Ca2+ entry (SOCE) was detected by calcium imaging after 7 days of high-glucose (HG) or normal-glucose (NG) exposure, the expression levels of Orais after HG treatment was detected by western blot analysis. The effect of HG exposure on the expression of phosphorylated (p)-VE-cadherin and VE-cadherin on cell membrane was observed by immunofluorescence assay. HG-induced transendothelial electrical resistance was examined in vitro after MAECs were cultured in HG medium. FD-20 permeability was tested in monolayer aortic endothelial cells through transwell permeability assay. The interactions between Orais and VE-cadherin were detected by co-immunoprecipitation and immunofluorescence technologies. Immunohistochemical experiment was used to detect the expression changes of Orais, VE-cadherin and p-VE-cadherin in aortic endothelium of mice with diabetes.Results(1) The expression levels of Orais and activity of SOCE were significantly increased in MAECs cultured in HG for 7 days. (2) In MAECs cultured in HG for 7 days, the ratio of p-VE-cadherin to VE-cadherin expressed on the cell membrane and the FD-20 permeability in monolayer endothelial cells increased, indicating that intercellular permeability increased. (3) Orais and VE-cadherin can interact and enhance the interaction ratio through HG stimulation. (4) In MAECs cultured with HG, the SOCE activator ATP enhanced the expression level of p-VE-cadherin, and the SOCE inhibitor BTP2 decreased the expression level of p-VE-cadherin. (5) Significantly increased expression of p-VE-cadherin and Orais in the aortic endothelium of mice with diabetes.ConclusionHG exposure stimulated increased expression of Orais in endothelial cells, and increased VE-cadherin phosphorylation through Orais–VE-cadherin complex and a series of downstream signaling pathways, resulting in disruption of endothelial cell junctions and initiation of atherosclerosis.

Parathyroid Hormone Promotes Human Umbilical Vein Endothelial Cell Migration and Proliferation Through Orai1-Mediated Calcium Signaling

“…When NFATC1 translocates from the cytosol to the nucleus, it can bind to gene promoter regions and induce the expression of numerous genes ( 29 ). Therefore, we next investigated the role of the calmodulin/calcineurin/NFATC1 signaling pathway on the regulation of COL1A1 expression.…”

“…In fact, many studies have indicated that SOCErelated proteins, including Orais and STIM1, affect the vascular system in a variety of pathological conditions. The Orai1 protein, which is located in the endothelial cell plasma membrane, is involved in various dysfunctions of the endothelium (12,(29)(30)(31). For example, Orai1 and STIM1 mediate histamine-induced endothelial inflammation, and Orai1 is involved in endoplasmic reticulum stress-induced endothelial dysfunction (33,34).…”

“…Endothelial dysfunction is a critical risk factor for vascular diseases and plays a key role in atherosclerosis, hypertension, diabetes and CVD ( 29 , 32 ). PTH is associated with several CVDs ( 5 , 9 , 33 ).…”

“…of Orai1-Mediated Ca 2+ Signaling in NFATC1 Translocation in PTH Effects on HUVECs NFAT acts as a Ca 2+ -sensitive transcription factor, integrating Ca 2+ signaling with other pathways involved in diverse cellular functions, such as cell survival, proliferation, migration, invasion, and angiogenesis (27). After dephosphorylation by calcineurin, NFAT proteins translocate from the cytosol to the nucleus, where they bind to promoter regions to turn on the expression of numerous genes (14,28,29). To explore the effect of PTH on NFAT signaling in endothelial cells, we conducted immunofluorescence assays.…”

Role of TRPV4 in the Diagnosis and Treatment of Helicobacter pylori Infection in Children with Duodenal Ulcers

“…Activation of TRPV4 caused an increase in the intracellular Ca 2+ concentration through influx of extracellular Ca 2+ , triggering an event which is accompanied by a downregulation of the tight junctional proteins claudin -1, -3, -4, -5, -7, and -8 and by dramatic changes in tight junction morphology, including frequent large breaks in the tight junction strands [ 26 ]. In addition, calcium/calmodulin-dependent protein kinase can enhance the phosphorylation of adhesin proteins such as VE-cadherin and resulting in disruption of epithelial cell junctions [ 27 ]. The activation of TRPV4 in the gastrointestinal tract causes experimental colitis in mice, which also causes the downregulation of claudin-7 and changes in tight junction morphology [ 22 ].…”