Lysosomal enzymes are decreased in the kidney of diabetic rats

Autor(es)

Peres, Giovani B. ; Juliano, Maria A. ^[1] ; Simoes, Manuel J. ^[2] ; Michelacci, Yara M. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Biofis, Escola Paulista Med, BR-04044020 Sao Paulo - Brazil

^[2] Univ Fed Sao Paulo, Dept Morfol, Escola Paulista Med, BR-04044020 Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Disciplina Biol Mol, Dept Bioquim, Escola Paulista Med, BR-04044020 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE; v. 1832, n. 1, p. 85-95, JAN 2013.
• Citações Web of Science: 18

Resumo

The objective of the present study was to investigate the expression and activities of lysosomal enzymes that act upon proteins and sulfated polysaccharides in diabetic rat kidney. Cathepsins, glycosidases and sulfatases were studied on the 10th (DM-10) and on the 30th (DM-30) day of streptozotocin-induced diabetes mellitus (DM). The activity of cathepsin B, the main kidney cysteine protease, was decreased both in DM-10 and DM-30. Gel filtration chromatography of urinary proteins has shown the prevalence of low molecular weight peptides in normal and DM-10 urine, in contrast to the prevalence of high molecular weight peptides and intact proteins in DM-30. These results show that the decrease in lysosomal proteases could explain, at least in part, the increased albuminuria detected by radial immunodiffusion (RID), due to the excretion of less degraded or intact albumin. Concerning sulfated polysaccharides, the activities of beta-glucuronidase, N-acetyl-beta-D-glucosaminidase, and N-acetyl-beta-D-galactosaminidase were also decreased in DM-30, while aryl sulfatases did not vary. Increased toluidine blue metachromatic staining of the tissue suggests that the lower activities of glycosidases could lead to intracellular deposition of partially digested molecules, and this could explain the decreased urinary excretion and increased tissue buildup of these molecules. The main morphological changes observed in kidney were proximal convoluted tubules with thinner walls and thinner brush border. Immunohistochemistry revealed that most of cathepsin B was located in the brush border of proximal tubular cells, highlighting the involvement of proximal convoluted tubules in diabetic nephropathy. (C) 2012 Elsevier B.V. All rights reserved. (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: 09/11817-2 - Expressão de enzimas lisossomais e metaloproteases em modelo experimental de diabetes mellitus
• Beneficiário: Giovani Bravin Peres
• Modalidade de apoio: Bolsas no Brasil - Mestrado