| First Author | Münzer P | Year | 2014 |
| Journal | Am J Physiol Cell Physiol | Volume | 307 |
| Issue | 10 | Pages | C920-7 |
| PubMed ID | 25231106 | Mgi Jnum | J:223590 |
| Mgi Id | MGI:5659793 | Doi | 10.1152/ajpcell.00029.2014 |
| Citation | Munzer P, et al. (2014) Sphingosine kinase 1 (Sphk1) negatively regulates platelet activation and thrombus formation. Am J Physiol Cell Physiol 307(10):C920-7 |
| abstractText | Sphingosine 1-phosphate (S1P) is a powerful regulator of platelet formation. Enzymes generating S1P include sphingosine kinase 1. The present study thus explored the role of sphingosine kinase 1 in platelet formation and function. Activation-dependent platelet integrin alphaIIbbeta3 activation and secretion of platelets lacking functional sphingosine kinase 1 (sphk1(-/-)) and of wild-type platelets (sphk1(+/+)) were determined utilizing flow cytometry and chronolume luciferin assay. Cytosolic Ca(2+) activity ([Ca(2+)]i) and aggregation were measured using fura-2 fluorescence and aggregometry, respectively. In vitro platelet adhesion and thrombus formation were evaluated using a flow chamber with shear rates of 1,700 s(-1). Activation-dependent increase of [Ca(2+)]i, degranulation (release of alpha and dense granules), integrin alphaIIbbeta3 activation, and aggregation were all significantly increased in sphk1(-/-) platelets compared with sphk1(+/+) platelets. Moreover, while platelet adhesion and thrombus formation under arterial shear rates were significantly augmented in Sphk1-deficient platelets, bleeding time and blood count were unaffected in sphk1(-/-) mice. In conclusion, sphingosine kinase 1 is a powerful negative regulator of platelet function counteracting degranulation, aggregation, and thrombus formation. |
