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High glucose-induced PKC activation mediates TGF-beta 1 and fibronectin synthesis by peritoneal mesothelial cells.
Kidney Int. 2001 Feb; 59(2):463-70.KI

Abstract

BACKGROUND

Progressive peritoneal fibrosis, membrane hyperpermeability, and ultrafiltration failure have been observed in long-term peritoneal dialysis (PD) using glucose as an osmotic agent. High glucose activates protein kinase C (PKC), which is one important signal pathway in the activation of transforming growth factor-beta 1 (TGF-beta 1) and fibronectin (FN). To gain a better understanding of mechanisms involved in peritoneal fibrosis, we examined the effects of high glucose on human peritoneal mesothelial cell (HPMC) TGF-beta 1 and FN mRNA expression and protein synthesis and determined the involvement of PKC in the high glucose-induced HPMC activation.

METHODS

Synchronized confluent HPMC were incubated with different concentrations of glucose with and without inhibition of PKC. PKC activity and diacylglycerol (DAG) levels were measured. The expression of TGF-beta 1 and FN mRNAs by HPMC was measured by Northern blot analysis. TGF-beta 1 protein was measured by enzyme-linked immunosorbent assay (ELISA) and mink lung epithelial cell growth inhibition assay. FN protein was measured by Western blot analysis and ELISA.

RESULTS

PKC activity and DAG levels in HPMC cultured under 50 mmol/L (high) glucose increased 2.3- and 2.0-fold, respectively, that of 5.6 mmol/L (control) glucose at 24 hours and this was sustained up to 72 hours. The expression of TGF-beta 1 and FN mRNA by HPMC cultured under high glucose increased 1.6- and 1.7-fold, respectively, that of control values at 24 hours. TGF-beta bioactivity as well as protein content in heat-activated conditioned media from high glucose was significantly higher than that of control values at 24 and 48 hours. FN protein also increased in response to high glucose, as measured by Western blot analysis and ELISA. PKC activator phorbol 12-myristate 13-acetate (PMA) induced 2.2- and 1.4-fold increase in TGF-beta 1 and FN mRNA expression, respectively. Depletion of PKC and calphostin C, a PKC inhibitor, effectively prevented both PMA and high glucose-induced, but not constitutive, expression of TGF-beta 1 and FN.

CONCLUSION

The present data demonstrate that high glucose up-regulates TGF-beta 1 and FN synthesis by HPMC, and that this high glucose-induced up-regulation is largely mediated by PKC. These results suggest that activation of PKC by high glucose in conventional PD solutions may constitute an important signal for activation of HPMC, leading to progressive accumulation of extracellular matrix and eventual peritoneal fibrosis.

Authors+Show Affiliations

Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11168928

Citation

Ha, H, et al. "High Glucose-induced PKC Activation Mediates TGF-beta 1 and Fibronectin Synthesis By Peritoneal Mesothelial Cells." Kidney International, vol. 59, no. 2, 2001, pp. 463-70.
Ha H, Yu MR, Lee HB. High glucose-induced PKC activation mediates TGF-beta 1 and fibronectin synthesis by peritoneal mesothelial cells. Kidney Int. 2001;59(2):463-70.
Ha, H., Yu, M. R., & Lee, H. B. (2001). High glucose-induced PKC activation mediates TGF-beta 1 and fibronectin synthesis by peritoneal mesothelial cells. Kidney International, 59(2), 463-70.
Ha H, Yu MR, Lee HB. High Glucose-induced PKC Activation Mediates TGF-beta 1 and Fibronectin Synthesis By Peritoneal Mesothelial Cells. Kidney Int. 2001;59(2):463-70. PubMed PMID: 11168928.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - High glucose-induced PKC activation mediates TGF-beta 1 and fibronectin synthesis by peritoneal mesothelial cells. AU - Ha,H, AU - Yu,M R, AU - Lee,H B, PY - 2001/2/13/pubmed PY - 2001/4/6/medline PY - 2001/2/13/entrez SP - 463 EP - 70 JF - Kidney international JO - Kidney Int VL - 59 IS - 2 N2 - BACKGROUND: Progressive peritoneal fibrosis, membrane hyperpermeability, and ultrafiltration failure have been observed in long-term peritoneal dialysis (PD) using glucose as an osmotic agent. High glucose activates protein kinase C (PKC), which is one important signal pathway in the activation of transforming growth factor-beta 1 (TGF-beta 1) and fibronectin (FN). To gain a better understanding of mechanisms involved in peritoneal fibrosis, we examined the effects of high glucose on human peritoneal mesothelial cell (HPMC) TGF-beta 1 and FN mRNA expression and protein synthesis and determined the involvement of PKC in the high glucose-induced HPMC activation. METHODS: Synchronized confluent HPMC were incubated with different concentrations of glucose with and without inhibition of PKC. PKC activity and diacylglycerol (DAG) levels were measured. The expression of TGF-beta 1 and FN mRNAs by HPMC was measured by Northern blot analysis. TGF-beta 1 protein was measured by enzyme-linked immunosorbent assay (ELISA) and mink lung epithelial cell growth inhibition assay. FN protein was measured by Western blot analysis and ELISA. RESULTS: PKC activity and DAG levels in HPMC cultured under 50 mmol/L (high) glucose increased 2.3- and 2.0-fold, respectively, that of 5.6 mmol/L (control) glucose at 24 hours and this was sustained up to 72 hours. The expression of TGF-beta 1 and FN mRNA by HPMC cultured under high glucose increased 1.6- and 1.7-fold, respectively, that of control values at 24 hours. TGF-beta bioactivity as well as protein content in heat-activated conditioned media from high glucose was significantly higher than that of control values at 24 and 48 hours. FN protein also increased in response to high glucose, as measured by Western blot analysis and ELISA. PKC activator phorbol 12-myristate 13-acetate (PMA) induced 2.2- and 1.4-fold increase in TGF-beta 1 and FN mRNA expression, respectively. Depletion of PKC and calphostin C, a PKC inhibitor, effectively prevented both PMA and high glucose-induced, but not constitutive, expression of TGF-beta 1 and FN. CONCLUSION: The present data demonstrate that high glucose up-regulates TGF-beta 1 and FN synthesis by HPMC, and that this high glucose-induced up-regulation is largely mediated by PKC. These results suggest that activation of PKC by high glucose in conventional PD solutions may constitute an important signal for activation of HPMC, leading to progressive accumulation of extracellular matrix and eventual peritoneal fibrosis. SN - 0085-2538 UR - https://www.unboundmedicine.com/medline/citation/11168928/High_glucose_induced_PKC_activation_mediates_TGF_beta_1_and_fibronectin_synthesis_by_peritoneal_mesothelial_cells_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0085-2538(15)47496-4 DB - PRIME DP - Unbound Medicine ER -