Mdia1 is Crucial for Advanced Glycation End Product-Induced Endothelial Hyperpermeability

Abstract

Background/Aims: Disruption of endothelial barrier integrity in response to advanced glycation end products (AEGs) stimulation contributes to vasculopathy associated with diabetes mellitus. Mammalian diaphanous-related formin (mDia1) has been reported to bind to the cytoplasmic domain of the receptor for advanced glycation end products (RAGE), which induces a series of cellular processes. This study directly evaluated the participation of mDia1 in AGE-induced hyperpermeability and revealed the precise intracellular signal transductions of this pathological process. Methods: Human umbilical vein endothelial cells (HUVECs) were used in the in vitro studies. Trans-endothelial electric resistance and permeability coefficient for dextran (Pd) were measured to analyze cell permeability. Western blotting, immunofluorescence staining and flow cytometry assay were performed to investigate the underlying mechanism. Dextran flux across the mesentery in mice was monitored to investigate in vivo microvascular permeability. Results: we found that AGEs evoked Nox4 membrane translocation, reactive oxygen species production, phosphorylation of Src and VE-cadherin, dissociation of adherens junctions and eventual endothelial hyperpermeability through RAGE-mDia1 binding. Cells overexpressing mDia1 by recombinant adenovirus infection showed stronger cellular responses induced by AGEs. Down-regulation of mDia1 by infection with an adenovirus encoding siRNA or blockade of RAGE-mDia1 binding by transfection with RAGE mutant plasmids into HUVECs abolished these AGE-induced effects. Furthermore, knockdown of mDia1 using an adenovirus or genetical knockout of RAGE in C57 mice rescued AGE-evoked microvascular hyperpermeability. Conclusion: Our study revealed that mDia1 plays a critical role in AGE-induced microvascular hyperpermeability through binding to RAGE.

Soluble RAGE attenuates AngII-induced endothelial hyperpermeability by disrupting HMGB1-mediated crosstalk between AT1R and RAGE

“…Additionally, regarding RAGE signaling in endothelial hyperpermeability, mammalian diaphanous 1 (mDia1), a member of the diaphanous-related formin family, was recently identified as a new signaling molecule in AGE-induced endothelial hyperpermeability. Mechanistically, mDia1 transduces signaling via binding to the cytoplasmic domain of RAGE (ctRAGE) 24,25 .…”

“…It has been reported that RAGE-mediated signal transduction requires interaction of the RAGE cytoplasmic domain with the FH1 domain of the formin mDia1 (refs. 25,48 ). Furthermore, according to our data, RAGE not only requires mDia1 to transmit the signal downstream (Fig.…”

Advanced glycation end-products regulate extracellular matrix-adipocyte metabolic crosstalk in diabetes

“…AGE represent a putative mechanism underlying ECM-adipocyte interactions, possibly via signaling through Rho GTPases, a downstream signaling pathway activated by AGE 17 . Rho GTPases regulate insulin-stimulated glucose uptake in muscle and adipose tissue 18 , and AGE activate Rho signaling in endothelial and microglial cells 19–23 , but no published data link AGE and Rho signaling in adipose tissue dysfunction.…”

Non-Enzymatic Methylglyoxal Formation From glucose Metabolites and Generation of Superoxide Anion Radical During Methylglyoxal-Dependent Cross-Links Reaction

“…Glycation of biopolymers by reactive carbonyl compounds (Maillard reaction) leads to the formation of the advanced glycation end products -the biomarkers of pathophysiological processes associated with diabetes and various other metabolically grounded diseases [5,7,10]. Using different regulatory pathways, these products can provoke NADPH oxidase and mitochondria to form a superoxide radical [3,24,37].…”