High glucose decreases collagenase expression and increases TIMP expression in cultured human peritoneal mesothelial cells

• Published in: Nephrology, dialysis, transplantation Vol. 23; no. 2; pp. 534 - 541
• Main Authors: Kim, Jin-Ju, Li, Jin-Ji, Kim, Kyung Sik, Kwak, Seung-Jae, Jung, Dong-Sub, Ryu, Dong-Ryeol, Yoo, Tae-Hyun, Choi, Hoon Young, Han, Seung Hyeok, Kim, Hyung Jong, Yoon, Soo Young, Han, Dae Suk, Kang, Shin-Wook
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.02.2008; Oxford Publishing Limited (England)
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Cells, Cultured; collagenases; Collagenases - biosynthesis; Collagenases - genetics; Emergency and intensive care: renal failure. Dialysis management; Epithelial Cells - metabolism; Fibrillar Collagens - metabolism; Fibrosis; Glomerulonephritis; Glucose - administration & dosage; high glucose; Humans; Intensive care medicine; Medical sciences; mesothelial cells; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; peritoneal fibrosis; Peritoneum - cytology; Peritoneum - pathology; RNA, Messenger - biosynthesis; TIMPs; Tissue Inhibitor of Metalloproteinases - biosynthesis; peritoneal fibrosis; TIMPs; collagenases; mesothelial cells; high glucose; Kidney disease; Human; Cell culture; Urinary system disease; Hemodialysis; Glucose; Extrarenal dialysis; Fibrosis; Renal failure
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfm553

Background. Peritoneal fibrosis (PF), a serious problem in long-term continuous ambulatory peritoneal dialysis (CAPD) patients, is characterized by extracellular matrix (ECM) accumulation which results from an imbalance between the synthesis and the degradation of ECM components. Previous studies have demonstrated that ECM synthesis is increased in human peritoneal mesothelial cells (HPMCs) under high glucose conditions, but the effects of high glucose on degradative pathways have not been fully explored. This study was undertaken to elucidate the effects of high glucose on these proteolytic processes in cultured HMPCs. Methods. HPMCs were isolated from human omentum and were exposed to 5.6 mM glucose (NG), 5.6 mM glucose +34.4 mM mannitol (NG + M), or 40 mM glucose (HG) with or without PKC inhibitor (PKCi). Real-time PCR and western blot were performed to determine collagenases (MMP-1, -8 and -13) and TIMPs (TIMP-1 and -2) mRNA and protein expression, respectively. The individual activities of collagenases in culture media were determined by ELISA. Results. Types I and III collagen protein expression were significantly increased in HG-conditioned media compared to NG media (P < 0.05). The MMP-1, -8 and -13/GAPDH mRNA ratios were significantly lower in HPMCs exposed to HG medium compared to NG cells by 64, 52 and 37%, respectively, and their protein expression by 76, 42 and 49%, respectively, in HG- vs NG-conditioned media. The activities of collagenases in HG-conditioned media were also significantly lower than those in NG media (P < 0.05). In contrast, HG significantly increased TIMPs mRNA ratios and protein expression in HPMCs. These changes in collagenase and TIMP expression induced by HG were abrogated upon pre-treatment with PKCi. Conclusion. In conclusion, impaired matrix degradation may contribute to ECM accumulation in PF.