| Autor: |
Rehana Perveen, Kevin Funk, Jean Thuma, Shelli Wulf Ridge, Yanyan Cao, Jan Willem N Akkerman, Xiaozhuo Chen, Huzoor Akbar |
| Jazyk: |
angličtina |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
PLoS ONE, Vol 6, Iss 11, p e26238 (2011) |
| Druh dokumentu: |
article |
| ISSN: |
1932-6203 |
| DOI: |
10.1371/journal.pone.0026238 |
| Popis: |
BACKGROUND: We have shown that 1,2,3,4,6-penta-O-galloyl-α-D-glucopyranose (α-PGG), an orally effective hypoglycemic small molecule, binds to insulin receptors and activates insulin-mediated glucose transport. Insulin has been shown to bind to its receptors on platelets and inhibit platelet activation. In this study we tested our hypothesis that if insulin possesses anti-platelet properties then insulin mimetic small molecules should mimic antiplatelet actions of insulin. PRINCIPAL FINDINGS: Incubation of human platelets with insulin or α-PGG induced phosphorylation of insulin receptors and IRS-1 and blocked ADP or collagen induced aggregation. Pre-treatment of platelets with α-PGG inhibited thrombin-induced release of P-selectin, secretion of ATP and aggregation. Addition of ADP or thrombin to platelets significantly decreased the basal cyclic AMP levels. Pre-incubation of platelets with α-PGG blocked ADP or thrombin induced decrease in platelet cyclic AMP levels but did not alter the basal or PGE(1) induced increase in cAMP levels. Addition of α-PGG to platelets blocked agonist induced rise in platelet cytosolic calcium and phosphorylation of Akt. Administration of α-PGG (20 mg kg(-1)) to wild type mice blocked ex vivo platelet aggregation induced by ADP or collagen. CONCLUSIONS: These data suggest that α-PGG inhibits platelet activation, at least in part, by inducing phosphorylation of insulin receptors leading to inhibition of agonist induced: (a) decrease in cyclic AMP; (b) rise in cytosolic calcium; and (c) phosphorylation of Akt. These findings taken together with our earlier reports that α-PGG mimics insulin signaling suggest that inhibition of platelet activation by α-PGG mimics antiplatelet actions of insulin. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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