Advanced glycation end products depress function of endothelial progenitor cells via p38 and ERK 1/2 mitogen-activated protein kinase pathways.
OBJECTIVE
Advanced glycation end products (AGEs) and endothelial progenitor cells (EPCs) play divergent roles in the process of atherosclerosis. We investigated the effects of AGE-human serum albumin (AGE-HSA) on receptor expression for AGEs (RAGE) and EPCs apoptosis.


METHODS
The human mononuclear cells were obtained by Ficoll density gradient centrifugation and cultured in M199 medium containing rh-VEGF (30 ng/ml), rh-b-FGF(6 ng/ml) and 20% NBCS for 8 days. The adhesive EPCs were sequentially harvested after 24 h synchronization and challenged with AGE-HSA (concentration range from 0 to 300 microg/ml) for 24 h and 200 microg/ml AGE-HSA (time range from 0 to 36 h). EPCs apoptosis and migration were determined, expressions of RAGE, phosphorylated ERK1/2, JNK and p38 mitogen-activated protein kinase (MAPK) of EPCs were quantified by fluorescent quantitation RT-PCR and Western-blot, effect of AGE-HSA on NF-kappaB activtiy was determined by EMSA (electrophoretic mobility shift assay) in the presence and absence of special MAPK pathways pathway inhibitors.


RESULTS
AGE-HSA upregulated the expression of RAGE, this effect could be significantly inhibited by p38 MAPK and ERK MAPK inhibitor, but not by JNK MAPK inhibitor. AGE-HSA also promoted EPCs apoptosis and inhibited EPCs migration and increased NF-kappaB activity, these effects could be significantly attenuated by the anti-RAGE neutralizing antibody as well as by p38 and ERK MAPK inhibitors.


CONCLUSIONS
AGE-HSA could promote atherosclerosis by upregulating EPCs RAGE expressions and promoting EPCs apoptosis via p38, ERK MAPK pathways, activation of NF-kappaB might also play a role in this process.
Sun
Chengbo
C
Dept. of Cardiology, 2nd Hospital Affiliated to the Second Military Medical University, Shanghai, People's Republic of China.
Liang
Chun
C
Ren
Yusheng
Y
Zhen
Yi
Y
He
Zhiqing
Z
Wang
Hua
H
Tan
Hongbing
H
Pan
Xiaoming
X
Wu
Zonggui
Z
D003470:Culture Media; D017931:DNA Primers; D042783:Endothelial Cells / Q000187:drug effects / Q000502:physiology*; D017930:Genes, Reporter; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D016328:NF-kappa B / Q000502:physiology; D016133:Polymerase Chain Reaction; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D003470:Culture Media; D017931:DNA Primers; D017127:Glycation End Products, Advanced; D016328:NF-kappa B; D049452:Green Fluorescent Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases