[Advanced glycation end products stimulate human endothelial cells to produce monocyte chemoattractant protein-1].
OBJECTIVE
To investigate the effects of advanced glycation end products (AGE) on secretion of monocyte chemoattractant protein-1 (MCP-1) by human endothelial cells and its signal transduction pathway.


METHODS
Human umbilical vein endothelial cells (HUVECs) and HUVEC-derived cell line (ECV304) were cultured in vitro with indicated concentration of AGE modified human serum albumin (AGE-HSA) or AGE modified bovine serum albumin (AGE-BSA). The production of MCP-1 was evaluated by Western blotting and enzyme-linked immunoadsorbent assay (ELISA). The MCP-1 mRNA expression was assayed by reverse-transcription polymerase chain reaction (RT-PCR). Intracellular oxidative stress was detected by flow cytometry. The phosphorylation activity of cellular p38 mitogen-activated protein kinase (p38-MAPK) was analyzed by Western blotting using a phospho-specific antibody.


RESULTS
AGE-HSA and AGE-BSA, but not their unmodified form, upregulated the expression of MCP-1 mRNA and protein dose- and time-dependently. The MCP-1 concentration in the supernatant of HUVECs incubated with 50 micro g/ml AGE-HSA for 12 hours increased from 48.3 pg/ micro g +/- 0.6 pg/ micro g protein to 148.1 pg/ micro g +/- 12.6 pg/ micro g protein (P < 0.01). AGE modified proteins were associated with enhanced oxidative stress and p38-MAPK phosphorylation activity. Incubation of HUVECs with 50 micro g/ml AGE-HSA for 30 minutes resulted in increase of p38-MAPK phosphorylation activity by 91% +/- 14% (P < 0.01). Antioxidant or SB 203580, a specific inhibitor of p38, could block the over-expression of MCP-1.


CONCLUSIONS
AGE modified proteins stimulate endothelial cells to produce MCP-1 through activation of the p38 signal pathway. This effect may contribute to the pathogenesis of atherosclerosis seen in AGE-associated diseases.
Guo
Zhi-jian
ZJ
Department of Nephrology, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
Hou
Fan-fan
FF
Liang
Min
M
Wang
Li
L
Zhang
Xun
X
Liu
Zhi-qiang
ZQ
D000111:Acetylcysteine / Q000494:pharmacology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000096:biosynthesis* / Q000235:genetics; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D012709:Serum Albumin / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D000075462:Serum Albumin, Human; D048051:p38 Mitogen-Activated Protein Kinases
D018932:Chemokine CCL2; D017127:Glycation End Products, Advanced; D007093:Imidazoles; D011725:Pyridines; D012333:RNA, Messenger; D012709:Serum Albumin; C081628:advanced glycation end products-bovine serum albumin; C109748:advanced glycation end products-human serum albumin; D012710:Serum Albumin, Bovine; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; D000111:Acetylcysteine; D000075462:Serum Albumin, Human