Korean J Nephrol.  2002 Jan;21(1):20-28.

N epsilon(Carboxymethyl)Lysine-Induced Mesangial Cell Activation

• Lim HJ
• Song JS
• Ha HJ
• Lee HB

Abstract

BACKGROUND: Advanced glycation end products (AGE) are independent risk factors in the development and progression of diabetic nephropathy. Receptor for AGE(RAGE) is considered the main receptor involved in AGE-induced cell activation. Galectin-3, another AGE receptor, has recently been found upregulated in mesangial cells(MC) cultured under high glucose and in diabetic rat kidneys. N epsilon(carboxymethyl)lysine(CML) is a well characterized AGE but its role in MC activation is unknown. The present study examined the effects of CML on MC proliferation and extracellular matrix(ECM) secretion.
METHODS
Synchronized rat MC were stimulated with different concentrations of CML-bovine serum albumin(BSA), control BSA, and transforming growth factor-beta(TGF-beta) for up to 72 hours. Cell proliferation was measured by [3H]-thymidine incorporation. Fibronectin, TGF-beta, plasminogen activator inhibitor(PAI)-1 secreted into the media and RAGE and galectin-3 expression in MC were measured by Western blot analysis and ELISA.
RESULTS
1,000 micro /mL of CML-BSA decreased [3H]-thymidine incorporation by MC at 48 hours and 10 ng/mL TGF-beta at 24 and 48 hours. CML-BSA 100 and 1,000 micro /mL, control BSA 1,000 micro /mL, and TGF-beta 10 ng/mL increased fibronectin secretion at 48 hours. CML-BSA up to 1,000 micro /mL did not affect TGF-beta or PAI-1 secretion. TGF-beta 10 ng/mL, however, significantly increased PAI-1 secretion. Cultured MC expressed both RAGE and galectin-3. CML-BSA 100 micro /mL upregulated galectin-3 expression.
CONCLUSION
CML-BSA decreased MC proliferation and increased fibronectin secretion, suggesting that CML may lead to ECM accumulation and glomerulosclerosis in diabetic animals. MC express RAGE and galectin-3 constitutively and CML-induced galectin-3 upregulation may have a role in AGE-induced MC activation.

Keyword

Advanced glycosylation end products; N epsilon(carboxymethyl)lysine; Proliferation; Fibronectin; Receptor for AGE; Galectin-3; Mesangial cells

MeSH Terms

Animals
Blotting, Western
Cell Proliferation
Diabetic Nephropathies
Enzyme-Linked Immunosorbent Assay
Fibronectins
Galectin 3
Glucose
Glycosylation End Products, Advanced
Kidney
Mesangial Cells*
Plasminogen Activator Inhibitor 1
Plasminogen Activators
Rage
Rats
Risk Factors
Transforming Growth Factor beta
Up-Regulation
Advanced Glycosylation End Product-Specific Receptor
Fibronectins
Galectin 3
Glucose
Glycosylation End Products, Advanced
Plasminogen Activator Inhibitor 1
Plasminogen Activators
Transforming Growth Factor beta