Endocytosis of Tight Junctions Caveolin Nitrosylation Dependent Is Improved by Cocoa Via Opioid Receptor on RPE Cells in Diabetic Conditions

Autor(es)

Rosales, Mariana Aparecida B. ^[1] ; Silva, Kamila Cristina ^[1] ; Duarte, Diego A. ^[1] ; Rossato, Franco Aparecido ^[2] ; de Faria, Jose B. Lopes ^[1] ; Lopes de Faria, Jacqueline M. ^[1]

Afiliação do(s) autor(es)

^[1] State Univ Campinas UNICAMP, Sch Med Sci, Renal Pathophysiol Lab & Invest Diabet Complicat, Campinas, SP - Brazil

^[2] State Univ Campinas UNICAMP, Sch Med Sci, Dept Clin Pathol, Bioenerget Lab, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE; v. 55, n. 9, p. 6090-6100, SEP 2014.
• Citações Web of Science: 11

Resumo

PURPOSE. Retinal pigment epithelium cells, along with tight junction (TJ) proteins, constitute the outer blood retinal barrier (BRB). Contradictory findings suggest a role for the outer BRB in the pathogenesis of diabetic retinopathy (DR). The aim of this study was to investigate whether the mechanisms involved in these alterations are sensitive to nitrosative stress, and if cocoa or epicatechin (EC) protects from this damage under diabetic (DM) milieu conditions. METHODS. Cells of a human RPE line (ARPE-19) were exposed to high-glucose (HG) conditions for 24 hours in the presence or absence of cocoa powder containing 0.5% or 60.5% polyphenol (low-polyphenol cocoa {[}LPC] and high-polyphenol cocoa {[}HPC], respectively). RESULTS. Exposure to HG decreased claudin-1 and occludin TJ expressions and increased extracellular matrix accumulation (ECM), whereas levels of TNF-alpha and inducible nitric oxide synthase (iNOS) were upregulated, accompanied by increased nitric oxide levels. This nitrosative stress resulted in S-nitrosylation of caveolin-1 (CAV-1), which in turn increased CAV-1 traffic and its interactions with claudin-1 and occludin. This cascade was inhibited by treatment with HPC or EC through delta-opioid receptor (DOR) binding and stimulation, thereby decreasing TNF-alpha-induced iNOS upregulation and CAV-1 endocytosis. The TJ functions were restored, leading to prevention of paracellular permeability, restoration of resistance of the ARPE-19 monolayer, and decreased ECM accumulation. CONCLUSIONS. The detrimental effects on TJs in ARPE-19 cells exposed to DM milieu occur through a CAV-1 S-nitrosylation-dependent endocytosis mechanism. High-polyphenol cocoa or EC exerts protective effects through DOR stimulation. (AU)

• Processo FAPESP: 11/06719-1 - O chá-verde (Camellia sinensis) e o tempol (mimético da superóxido dismutase) apresentam efeito protetor na patogênese da retinopatia diabética? Estudo in vitro em células humanas do epitélio pigmentar da retina (ARPE-19)
• Beneficiário: Jacqueline Mendonça Lopes de Faria
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/57560-0 - Efeitos do chá verde (Camellia sinensis), do cacau e de um doador de óxido nítrico na nefropatia e retinopatia diabética: papel da redução do estresse oxidativo e da inflamação e do aumento do óxido nítrico
• Beneficiário: Jose Butori Lopes de Faria
• Modalidade de apoio: Auxílio à Pesquisa - Temático