17Beta-oestradiol partially attenuates the inhibition of nitric oxide synthase-3 by advanced glycation end-products in human platelets.
1. Diabetes mellitus predisposes to and female sex protects against arterial thrombosis. The aim of the present study was to determine whether advanced glycation end-products (AGE), which accumulate in diabetes, impair platelet function through effects on platelet nitric oxide (NO) generation and whether this can be prevented by 17beta-oestradiol. 2. Aggregation responses of human platelet-rich plasma to ADP were determined in the absence or presence of 200 mg/L AGE-modified albumin (AGE-albumin), 10(-5) mol/L 17beta-oestradiol and 10(-5) mol/L ICI 182 780 (the pure oestrogen receptor antagonist). 3. Intraplatelet cGMP, an index of bioactive NO, was measured by radioimmunoassay and expression of nitric oxide synthase (NOS)-3, phosphoserine-1177-NOS-3 and O-glycosylated NOS-3 was quantified by western blotting in response to these same treatments. 4. Advanced glycation end-products-albumin increased platelet aggregatory responses to ADP. This increase was largely prevented by 17beta-oestradiol. Advanced glycation end-products-albumin decreased and 17beta-oestradiol increased intraplatelet NO-attributable cGMP and 17beta-oestradiol attenuated the AGE-albumin-induced decrease in NO-attributable cGMP. Despite no effect on NOS-3 expression, AGE-albumin decreased and 17beta-oestradiol increased phosphoserine-1177-NOS-3 and 17beta-oestradiol largely prevented the decrease in phosphoserine-1177-NOS-3 induced by AGE-albumin. Alone, AGE-albumin increased O-glycosylation of NOS-3 by N-acetylglucosamine, an effect largely inhibited by 17beta-oestradiol. 5. In conclusion, AGE-albumin inhibits platelet NO biosynthesis through effects on serine phosphorylation and O-glycosylation of platelet NOS-3 and this may explain, at least in part, the increase in platelet aggregability induced by AGE-albumin. These effects of AGE-albumin are largely prevented by 17beta-oestradiol. These actions may contribute to the effects of diabetes and sex on arterial thrombosis in vivo.
Chen
Lu
L
Laboratory of Reproductive Medicine, Atherosclerosis Research Centre, Nanjing Medical University, Nanjing, China.
Liu
Yuan
Y
Cui
Bota
B
Mi
Qiongyu
Q
Huang
Yan
Y
Fan
Leming
L
Chen
Qi
Q
Tang
James
J
Ferro
Albert
A
Ji
Yong
Y
D000117:Acetylglucosamine / Q000097:blood; D000328:Adult; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D015153:Blotting, Western; D006152:Cyclic GMP / Q000097:blood; D003627:Data Interpretation, Statistical; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D000077267:Fulvestrant; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors* / Q000302:isolation & purification; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects
D004791:Enzyme Inhibitors; D004965:Estrogen Antagonists; D017127:Glycation End Products, Advanced; D010768:Phosphoserine; D000077267:Fulvestrant; D004958:Estradiol; D052250:Nitric Oxide Synthase Type III; D006152:Cyclic GMP; D000117:Acetylglucosamine