Impact of high glucose and AGEs on cultured kidney-derived cells. Effects on cell viability, lysosomal enzymes and effectors of cell signaling pathways

Autor(es)

Peres, Giovani B. ; Schor, Nestor ; Michelacci, Yara M.

• Tipo de documento: Artigo Científico
• Fonte: Biochimie; v. 135, p. 137-148, APR 2017.
• Citações Web of Science: 4

Resumo

We have previously reported decreased expression and activities of lysosomal cathepsins B and L in diabetic kidney. Relevant morphological changes were observed in proximal tubules, suggesting that these cells are implicated in the early stages of the disease. The aim of the present study was to investigate the mechanisms that lead to these changes. The effects of high glucose (HG) and advanced glycation end products (AGEs) on cell viability, lysosomal enzymes and other effectors of cell signaling of cultured kidney cells were studied. HG increased viable mesangial cells (ihMC) in 48 h, while epithelial tubular cells were not affected (LLC-PK1 and MDCK). In contrast, the number of viable cells was markedly decreased, for all cell lines, by AGE-BSA. Concerning lysosomal enzymes, the main cysteine-protease expressed by these cells was cathepsin B, and its concentration was much higher in epithelial than in mesangial cells. Exposure to HG had no effect on the cathepsin B activity, but AGE-BSA caused a marked decrease in LLC-PK1, and increased the enzyme activities in the other cell lines. The levels of nitric oxide (NO) was increased by AGE-BSA in all cell lines, suggesting oxidative stress, and Western blotting has shown that, among the investigated proteins, cathepsin B, mTOR and transcription factor EB (TFEB) were the most significantly affected by exposure to AGE-BSA. As mTOR induces anabolism and inhibits autophagy, and TFEB is a master transcription factor for lysosomal enzymes, it is possible that this pathway plays a role in the inhibition of lysosomal enzymes in proximal tubule cells. Published by Elsevier B.V. (AU)

• Processo FAPESP: 10/16022-5 - Enzimas lisossomais, metaloproteinases e proteoglicanos em Diabetes mellitus
• Beneficiário: Yara Maria Corrêa da Silva Michelacci
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/03964-6 - Glicosaminoglicanos e proteoglicanos: relação estrutura e função
• Beneficiário: Helena Bonciani Nader
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/07109-8 - Expressão e atividade de enzimas lisossomais em células renais em cultura expostas a condições que mimetizam o estado diabético
• Beneficiário: Yara Maria Corrêa da Silva Michelacci
• Modalidade de apoio: Auxílio à Pesquisa - Regular