TY - JOUR
T1 - Evidence for STIM1- and Orai1-dependent store-operated calcium influx through ICRAC in vascular smooth muscle cells
T2 - Role in proliferation and migration
AU - Potier, Marie
AU - Gonzalez, José C.
AU - Motiani, Rajender K.
AU - Abdullaev, Iskandar F.
AU - Bisaillon, Jonathan M.
AU - Singer, Harold A.
AU - Trebak, Mohamed
PY - 2009/8
Y1 - 2009/8
N2 - The identity of store-operated calcium (Ca2+) entry (SOCE) channels in vascular smooth muscle cells (VSMCs) remains a highly contentious issue. Whereas previous studies have suggested that SOCE in VSMCs is mediated by the nonselective transient receptor potential canonical (TRPC) 1 protein, the identification of STIM1 and Orai1 as essential components of ICRAC, a highly Ca2+-selective SOCE current in leukocytes, has challenged that view. Here we show that cultured proliferative migratory VSMCs isolated from rat aorta (called "synthetic") display SOCE with classic features, namely inhibition by 2-aminoethoxydiphenyl borate, ML-9, and low concentrations of lanthanides. On store depletion, synthetic VSMCs and A7r5 cells display currents with characteristics of ICRAC. Protein knockdown of either STIM1 or Orai1 in synthetic VSMCs greatly reduced SOCE, whereas Orai2, Orai3, TRPC1, TRPC4, and TRPC6 knockdown had no effect. Orai1 knockdown reduced ICRAC in synthetic VSMCs and A7r5 cells. Synthetic VSMCs showed up-regulated STIM1/Orai1 proteins and SOCE compared with quiescent freshly isolated VSMC. Knockdown of STIM1 and Orai1 inhibited synthetic VSMC proliferation and migration, whereas STIM2, Orai2, and Orai3 knockdown had no effect. To our knowledge, these results are the first to show ICRAC in VSMCs and resolve a long-standing controversy by identifying CRAC as the elusive VSMC SOCE channel important for proliferation and migration.
AB - The identity of store-operated calcium (Ca2+) entry (SOCE) channels in vascular smooth muscle cells (VSMCs) remains a highly contentious issue. Whereas previous studies have suggested that SOCE in VSMCs is mediated by the nonselective transient receptor potential canonical (TRPC) 1 protein, the identification of STIM1 and Orai1 as essential components of ICRAC, a highly Ca2+-selective SOCE current in leukocytes, has challenged that view. Here we show that cultured proliferative migratory VSMCs isolated from rat aorta (called "synthetic") display SOCE with classic features, namely inhibition by 2-aminoethoxydiphenyl borate, ML-9, and low concentrations of lanthanides. On store depletion, synthetic VSMCs and A7r5 cells display currents with characteristics of ICRAC. Protein knockdown of either STIM1 or Orai1 in synthetic VSMCs greatly reduced SOCE, whereas Orai2, Orai3, TRPC1, TRPC4, and TRPC6 knockdown had no effect. Orai1 knockdown reduced ICRAC in synthetic VSMCs and A7r5 cells. Synthetic VSMCs showed up-regulated STIM1/Orai1 proteins and SOCE compared with quiescent freshly isolated VSMC. Knockdown of STIM1 and Orai1 inhibited synthetic VSMC proliferation and migration, whereas STIM2, Orai2, and Orai3 knockdown had no effect. To our knowledge, these results are the first to show ICRAC in VSMCs and resolve a long-standing controversy by identifying CRAC as the elusive VSMC SOCE channel important for proliferation and migration.
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U2 - 10.1096/fj.09-131128
DO - 10.1096/fj.09-131128
M3 - Article
C2 - 19364762
AN - SCOPUS:68849107084
SN - 0892-6638
VL - 23
SP - 2425
EP - 2437
JO - FASEB Journal
JF - FASEB Journal
IS - 8
ER -