Advanced glycation endproducts increase EPC apoptosis and decrease nitric oxide release via MAPK pathways.
OBJECTIVE
Previous studies have shown that advanced glycation endproducts (AGE) can induce endothelial progenitor cells (EPC) apoptosis, which contributes to the pathogenesis of diabetes mellitus. Nitric oxide (NO) signaling is closely associated with apoptosis. We therefore investigated the effects of AGE on human EPC apoptosis, NO release and related signal transduction pathways.


METHODS
EPC isolated from healthy human subjects were cultured with various concentrations of AGE (0, 2, 20 and 200mg/L) for 0, 24, 48 and 72 h in the presence or absence of various MAPK (ERK/P38/JNK) inhibitors, respectively. EPC apoptosis (detected by flow cytometric analyses) and NO concentration in culture supernatant were determined. The mRNA levels of eNOS, COX-2, Bcl-2 and Bax were assessed by RT-PCR and the protein expressions of NF-kappaB and Caspase-3 assessed by Western blot.


RESULTS
Increased EPC apoptosis and reduced NO release were induced by 200mg/L AGE, accompanied by a downregulation of eNOS and Bcl-2 expressions as well as an elevation in COX-2, Bax, NF-kappaB and Caspase-3 expressions in a time-dependent manner (all P<0.05). These changes were significantly attenuated by pretreatment with various MAPK (ERK/P38/JNK) inhibitors (P<0.05).


CONCLUSIONS
AGE can promote EPC apoptosis and decrease NO release via MAPK pathways.
Shen
C
C
Department of Cardiology, Zhongda Hospital, Southeast University; Nanjing, China.
Li
Q
Q
Zhang
Y C
YC
Ma
G
G
Feng
Y
Y
Zhu
Q
Q
Dai
Q
Q
Chen
Z
Z
Yao
Y
Y
Chen
L
L
Jiang
Y
Y
Liu
N
N
D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D017127:Glycation End Products, Advanced / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
D017127:Glycation End Products, Advanced; D012333:RNA, Messenger; D009569:Nitric Oxide; D020928:Mitogen-Activated Protein Kinases