Format

Send to

Choose Destination
See comment in PubMed Commons below
Circulation. 2008 Jan 1;117(1):52-60. Epub 2007 Dec 10.

Platelet sarcoplasmic endoplasmic reticulum Ca2+-ATPase and mu-calpain activity are altered in type 2 diabetes mellitus and restored by rosiglitazone.

Author information

1
Vascular Signaling Group, and Institut für Kardiovaskuläre Physiologie, Johann Wolfgang Goethe-Universität, Frankfurt, Germany.

Abstract

BACKGROUND:

Platelets from patients with type 2 diabetes mellitus display hyperaggregability and increased thrombogenic potential.

METHODS AND RESULTS:

In platelets from patients with type 2 diabetes mellitus, we found enhanced tyrosine nitration and inactivation of the sarcoplasmic endoplasmic reticulum Ca2+-ATPase (SERCA-2), elevated platelet [Ca2+]i, and activation of mu-calpain. The tyrosine nitration of SERCA-2 and the activation of mu-calpain in vitro in platelets from healthy volunteers could be evoked in vitro by peroxynitrite. Platelet endothelial cell adhesion molecule-1 was identified as a mu-calpain substrate; its in vitro degradation was stimulated by peroxynitrite and prevented by calpain inhibitors. Calpain activation also was linked to hyperresponsiveness to thrombin and the loss of platelet sensitivity to nitric oxide synthase inhibitors. Platelets from patients with type 2 diabetes mellitus (hemoglobin A1c >6.6%) contained little or no intact platelet endothelial cell adhesion molecule-1, whereas degradation products were detectable. The peroxisome proliferator-activated receptor-gamma agonist rosiglitazone increased SERCA-2 expression in megakaryocytes, and treating patients with type 2 diabetes mellitus with rosiglitazone for 12 weeks increased platelet SERCA-2 expression and Ca2+-ATPase activity, decreased SERCA-2 tyrosine nitration, and normalized platelet [Ca2+]i. Rosiglitazone also reduced mu-calpain activity, normalized platelet endothelial cell adhesion molecule-1 levels, and partially restored platelet sensitivity to nitric oxide synthase inhibition.

CONCLUSIONS:

These data identify megakaryocytes/platelets as additional cellular targets for peroxisome proliferator-activated receptor-gamma agonists and highlight potential benefits of rosiglitazone therapy in cardiovascular diseases.

[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center