The serum- and glucocorticoid-inducible kinase 1 (SGK1) influences platelet calcium signaling and function by regulation of Orai1 expression in megakaryocytes.
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The serum- and glucocorticoid-inducible kinase 1 (SGK1) influences platelet calcium signaling and function by regulation of Orai1 expression in megakaryocytes. / Borst, Oliver; Schmidt, Eva-Maria; Münzer, Patrick; Schönberger, Tanja; Towhid, Syeda T; Elvers, Margitta; Leibrock, Christina; Schmid, Evi; Eylenstein, Anja; Kuhl, Dietmar; May, Andreas E; Gawaz, Meinrad; Lang, Florian.
In: BLOOD, Vol. 119, No. 1, 1, 2012, p. 251-261.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - The serum- and glucocorticoid-inducible kinase 1 (SGK1) influences platelet calcium signaling and function by regulation of Orai1 expression in megakaryocytes.
AU - Borst, Oliver
AU - Schmidt, Eva-Maria
AU - Münzer, Patrick
AU - Schönberger, Tanja
AU - Towhid, Syeda T
AU - Elvers, Margitta
AU - Leibrock, Christina
AU - Schmid, Evi
AU - Eylenstein, Anja
AU - Kuhl, Dietmar
AU - May, Andreas E
AU - Gawaz, Meinrad
AU - Lang, Florian
PY - 2012
Y1 - 2012
N2 - Platelets are activated on increase of cytosolic Ca2+ activity ([Ca2+](i)), accomplished by store-operated Ca2+ entry (SOCE) involving the pore-forming ion channel subunit Orai1. Here, we show, for the first time, that the serum- and glucocorticoid-inducible kinase 1 (SGK1) is expressed in platelets and megakaryocytes. SOCE and agonist-induced [Ca2+](i) increase are significantly blunted in platelets from SGK1 knockout mice (sgk1(-/-)). Similarly, Ca2+ -dependent degranulation, integrin ?(IIb)?3 activation, phosphatidylserine exposure, aggregation, and in vitro thrombus formation were significantly impaired in sgk1(-/-) platelets, whereas tail bleeding time was not significantly enhanced. Platelet and megakaryocyte Orai1 transcript levels and membrane protein abundance were significantly reduced in sgk1(-/-) mice. In human megakaryoblastic cells (MEG-01), transfection with constitutively active (S422D)SGK1 but not with inactive (K127N)SGK1 significantly enhanced Orai1 expression and SOCE, while effects reversed by the SGK1 inhibitor GSK650394 (1?M). Transfection of MEG-01 cells with (S422D)SGK1 significantly increased phosphorylation of I?B kinase ?/? and I?B? resulting in nuclear translocation of NF-?B subunit p65. Treatment of (S422D)SGK1-transfected MEG-01 cells with the I?B kinase inhibitor BMS-345541 (10?M) abolished SGK1-induced increase of Orai1 expression and SOCE. The present observations unravel SGK1 as novel regulator of platelet function, effective at least in part by NF-?B-dependent transcriptional up-regulation of Orai1 in megakaryocytes and increasing platelet SOCE.
AB - Platelets are activated on increase of cytosolic Ca2+ activity ([Ca2+](i)), accomplished by store-operated Ca2+ entry (SOCE) involving the pore-forming ion channel subunit Orai1. Here, we show, for the first time, that the serum- and glucocorticoid-inducible kinase 1 (SGK1) is expressed in platelets and megakaryocytes. SOCE and agonist-induced [Ca2+](i) increase are significantly blunted in platelets from SGK1 knockout mice (sgk1(-/-)). Similarly, Ca2+ -dependent degranulation, integrin ?(IIb)?3 activation, phosphatidylserine exposure, aggregation, and in vitro thrombus formation were significantly impaired in sgk1(-/-) platelets, whereas tail bleeding time was not significantly enhanced. Platelet and megakaryocyte Orai1 transcript levels and membrane protein abundance were significantly reduced in sgk1(-/-) mice. In human megakaryoblastic cells (MEG-01), transfection with constitutively active (S422D)SGK1 but not with inactive (K127N)SGK1 significantly enhanced Orai1 expression and SOCE, while effects reversed by the SGK1 inhibitor GSK650394 (1?M). Transfection of MEG-01 cells with (S422D)SGK1 significantly increased phosphorylation of I?B kinase ?/? and I?B? resulting in nuclear translocation of NF-?B subunit p65. Treatment of (S422D)SGK1-transfected MEG-01 cells with the I?B kinase inhibitor BMS-345541 (10?M) abolished SGK1-induced increase of Orai1 expression and SOCE. The present observations unravel SGK1 as novel regulator of platelet function, effective at least in part by NF-?B-dependent transcriptional up-regulation of Orai1 in megakaryocytes and increasing platelet SOCE.
KW - Animals
KW - Humans
KW - Male
KW - Female
KW - Cells, Cultured
KW - Mice
KW - Mice, Knockout
KW - Reverse Transcriptase Polymerase Chain Reaction
KW - Flow Cytometry
KW - Fluorescent Antibody Technique
KW - Phosphorylation
KW - Blotting, Western
KW - Immunoenzyme Techniques
KW - Calcium/metabolism
KW - RNA, Messenger/genetics
KW - Bleeding Time
KW - Blood Platelets/metabolism
KW - Calcium Channels/genetics/metabolism
KW - Calcium Signaling
KW - Immediate-Early Proteins/physiology
KW - Leukemia, Megakaryoblastic, Acute/metabolism/pathology
KW - Megakaryocytes/cytology/metabolism
KW - NF-kappa B/genetics/metabolism
KW - Platelet Aggregation
KW - Protein-Serine-Threonine Kinases/physiology
KW - Thrombosis/etiology/metabolism/pathology
KW - Animals
KW - Humans
KW - Male
KW - Female
KW - Cells, Cultured
KW - Mice
KW - Mice, Knockout
KW - Reverse Transcriptase Polymerase Chain Reaction
KW - Flow Cytometry
KW - Fluorescent Antibody Technique
KW - Phosphorylation
KW - Blotting, Western
KW - Immunoenzyme Techniques
KW - Calcium/metabolism
KW - RNA, Messenger/genetics
KW - Bleeding Time
KW - Blood Platelets/metabolism
KW - Calcium Channels/genetics/metabolism
KW - Calcium Signaling
KW - Immediate-Early Proteins/physiology
KW - Leukemia, Megakaryoblastic, Acute/metabolism/pathology
KW - Megakaryocytes/cytology/metabolism
KW - NF-kappa B/genetics/metabolism
KW - Platelet Aggregation
KW - Protein-Serine-Threonine Kinases/physiology
KW - Thrombosis/etiology/metabolism/pathology
M3 - SCORING: Journal article
VL - 119
SP - 251
EP - 261
JO - BLOOD
JF - BLOOD
SN - 0006-4971
IS - 1
M1 - 1
ER -