Scavenging of intracellularly produced hocl with resveratrol protects insulin signaling in adipocytes

BARRERA FS, NULL; DI SCIULLO MP; CLAVELES CASAS FN; RAMIREZ DC; LOPEZ CM; GOMEZ MEJIBA SE

BIOCELL

INST HISTOL EMBRIOL-CONICET

Lugar: Henderson Nevada: Tech Science Press; Año: 2020 p. 36 - 37

0327-9545

Resveratrol is a cell-permeable trans-stilbene derivative that can scavenge intracellularly produced HOCl (J. Biol. Chem, 285:20062/71). Our diet-induced obesity B6-mouse model showed that epididymal AT expresses myeloperoxidase (MPO) in adipose tissue macrophages (ATM) that also express M1-pro-inflammatory markers (e.g., IL-6, iNOS). MPO expression was observed in ATM located in the typical crown-like structures; and also inside adipocytes. Tissue fractionation showed MPO mRNA in the ATM, but not in the stromal-vascular fraction. Treatment of these isolated adipocytes with H2O2 blocked glucose uptake. Based on these findings, we hypothesized that MPO interferes with AT insulin signaling by producing HOCl and causing oxidation of intracellular components involved in insulin-triggered signaling. To test this hypothesis, we differentiated human adipocytes and loaded them with human MPO. Treatment of MPO-loaded adipocytes with H2O2 caused intracellular production of HOCl, reduced insulintriggered GLUT-4 translocation to the membrane, and glucose uptake. Furthermore, 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-based immuno-spin trapping (Biochim Biophys Acta. 2014;1840(2):722-9) and MS-tandem showed radicalization of specific components of the insulin signaling (e.g., IRS-1/2, SOCS3, GLUT-4). These effects were prevented by resveratrol, but not by taurine or methionine because these cannot pass across the membrane. Together our findings suggest that resveratrol can protect insulin sensitivity in the obese AT by scavenging intracellularly produced HOCl. These findings are also in agreement with the role of resveratrol in protecting genomic DNA against intracellularly produced HOCl in MPO-loaded epithelial cells