TY - JOUR
T1 - Arhgef1 Plays a Vital Role in Platelet Function and Thrombogenesis
AU - Qasim, Hanan
AU - Karim, Zubair A.
AU - Hernandez, Keziah R.
AU - Lozano, Dante
AU - Khasawneh, Fadi T.
AU - Alshbool, Fatima Z.
N1 - Funding Information:
This research was supported, in part, by startup funds provided by the School of Pharmacy, The University of Texas at El Paso (to Alshbool). Lozano was supported in part by the National Institute of General Medical Sciences of the National Institutes of Health under award number R25GM123928. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. All experiments involving animals were performed in compliance with the institutional guidelines and were approved by The University of Texas at El Paso Institutional Animal Care and Use Committee. The authors declare that all supporting data are available within the article data. Requests for detailed analytic methods will be addressed by the corresponding author. For requests for the Arhgef1 deletion mice, these will be referred by the corresponding author to the Mary Lyon Centre at MRC Harwell (www.har.mrc.ac.uk), Oxfordshire, United Kingdom, and handled as per our Material Transfer Agreement. Thrombin, collagen, stir bars, and other disposables were from Chrono-Log Corporation, whereas U46619 was purchased from Abcam. Fluorescein isothiocyanate–conjugated anti–P-selectin, anti-Arhgef1, anti-actin, anti-RhoA, anti-pROCK, and anti-Rap1b antibodies were purchased from Cell Signaling Technology, Inc, whereas the anti-β3 and anti-G13 antibodies were from Sigma Aldrich. The JON/A antibody was from Emfret analytics.
Funding Information:
This research was supported, in part, by startup funds provided by the School of Pharmacy, The University of Texas at El Paso (to Alshbool). Lozano was supported in part by the National Institute of General Medical Sciences of the National Institutes of Health under award number R25GM123928. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Publisher Copyright:
© 2019 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.
PY - 2019/5/7
Y1 - 2019/5/7
N2 - Background: Platelets are the cellular mediators of hemostasis and thrombosis, and their function is regulated by a number of molecular mediators, such as small GTPases. These small GTPases are themselves regulated by guanine nucleotide exchange factors such as Arhgefs, several of which are found in platelets, including the highly expressed Arhgef1. However, the role of Arhgef1 in platelets has not yet been investigated. Methods and Results: We employed mice with genetic deletion of Arhgef1 (ie, Arhgef1−/−) and investigated their platelet phenotype by employing a host of in vivo and in vitro platelet assays. Our results indicate that Arhgef1−/− mice had prolonged carotid artery occlusion and tail bleeding times. Moreover, platelets from these mice exhibited defective aggregation, dense and α granule secretion, αIIbβ3 integrin activation, clot retraction and spreading, in comparison to their wild-type littermates. Finally, we also found that the mechanism by which Arhgef1 regulates platelets is mediated in part by a defect in the activation of the RhoA–Rho-associated kinase axis, but not Rap1b. Conclusions: Our data demonstrate, for the first time, that Arhgef1 plays a critical role in platelet function, in vitro and in vivo.
AB - Background: Platelets are the cellular mediators of hemostasis and thrombosis, and their function is regulated by a number of molecular mediators, such as small GTPases. These small GTPases are themselves regulated by guanine nucleotide exchange factors such as Arhgefs, several of which are found in platelets, including the highly expressed Arhgef1. However, the role of Arhgef1 in platelets has not yet been investigated. Methods and Results: We employed mice with genetic deletion of Arhgef1 (ie, Arhgef1−/−) and investigated their platelet phenotype by employing a host of in vivo and in vitro platelet assays. Our results indicate that Arhgef1−/− mice had prolonged carotid artery occlusion and tail bleeding times. Moreover, platelets from these mice exhibited defective aggregation, dense and α granule secretion, αIIbβ3 integrin activation, clot retraction and spreading, in comparison to their wild-type littermates. Finally, we also found that the mechanism by which Arhgef1 regulates platelets is mediated in part by a defect in the activation of the RhoA–Rho-associated kinase axis, but not Rap1b. Conclusions: Our data demonstrate, for the first time, that Arhgef1 plays a critical role in platelet function, in vitro and in vivo.
KW - Arhgef1
KW - cardiovascular diseases
KW - platelets
KW - small GTPases
KW - thrombosis
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U2 - 10.1161/JAHA.118.011712
DO - 10.1161/JAHA.118.011712
M3 - Article
C2 - 30994039
AN - SCOPUS:85064967656
SN - 2047-9980
VL - 8
JO - Journal of the American Heart Association
JF - Journal of the American Heart Association
IS - 9
M1 - e011712
ER -