TY - JOUR
T1 - Caveolin-1 regulation of store-operated Ca2+ influx in human airway smooth muscle
AU - Sathish, Venkatachalem
AU - Abcejo, Amard J.
AU - Thompson, Michael A.
AU - Sieck, Gary C.
AU - Prakash, Y. S.
AU - Pabelick, Christina M.
PY - 2012/8/1
Y1 - 2012/8/1
N2 - Caveolae, plasma membrane invaginations with constitutive caveolin proteins, harbour proteins involved in intracellular calcium ([Ca2+]i ) regulation. In human airway smooth muscle (ASM), store-operated Ca2+ entry (SOCE) is a key component of [Ca2+ ]i regulation, and contributes to increased [Ca2+]i in inflammation. SOCE involves proteins Orai1 and stromal interaction molecule (STIM)1. We investigated the link between caveolae, SOCE and inflammation in ASM. [Ca2+]i was measured in human ASM cells using fura-2. Small interference RNA (siRNA) or overexpression vectors were used to alter expression of caveolin-1 (Cav-1), Orai1 or STIM1. Tumour necrosis factor (TNF)-α was used as a representative pro-inflammatory cytokine. TNF-α increased SOCE following sarcoplasmic reticulum Ca2+ depletion, and increased wholecell and caveolar Orai1 (but only intracellular STIM1). Cav-1 siRNA decreased caveolar and whole-cell Orai1 (but not STIM1) expression, and blunted SOCE, even in the presence of TNF-α. STIM1 overexpression substantially enhanced SOCE: an effect only partially reversed by Cav-1 siRNA. In contrast, Orai1 siRNA substantially blunted SOCE even in the presence of TNF-α. Cav-1 overexpression significantly increased Orai1 expression and SOCE, especially in the presence of TNF-α. These results demonstrate that caveolar expression and regulation of proteins such as Orai1 are important for [Ca2+]i regulation in human ASM cells and its modulation during inflammation. Copyright
AB - Caveolae, plasma membrane invaginations with constitutive caveolin proteins, harbour proteins involved in intracellular calcium ([Ca2+]i ) regulation. In human airway smooth muscle (ASM), store-operated Ca2+ entry (SOCE) is a key component of [Ca2+ ]i regulation, and contributes to increased [Ca2+]i in inflammation. SOCE involves proteins Orai1 and stromal interaction molecule (STIM)1. We investigated the link between caveolae, SOCE and inflammation in ASM. [Ca2+]i was measured in human ASM cells using fura-2. Small interference RNA (siRNA) or overexpression vectors were used to alter expression of caveolin-1 (Cav-1), Orai1 or STIM1. Tumour necrosis factor (TNF)-α was used as a representative pro-inflammatory cytokine. TNF-α increased SOCE following sarcoplasmic reticulum Ca2+ depletion, and increased wholecell and caveolar Orai1 (but only intracellular STIM1). Cav-1 siRNA decreased caveolar and whole-cell Orai1 (but not STIM1) expression, and blunted SOCE, even in the presence of TNF-α. STIM1 overexpression substantially enhanced SOCE: an effect only partially reversed by Cav-1 siRNA. In contrast, Orai1 siRNA substantially blunted SOCE even in the presence of TNF-α. Cav-1 overexpression significantly increased Orai1 expression and SOCE, especially in the presence of TNF-α. These results demonstrate that caveolar expression and regulation of proteins such as Orai1 are important for [Ca2+]i regulation in human ASM cells and its modulation during inflammation. Copyright
KW - Asthma
KW - Caveolae
KW - Cytokine
KW - Inflammation
KW - Orai1
KW - Stromal interaction molecule 1
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U2 - 10.1183/09031936.00090511
DO - 10.1183/09031936.00090511
M3 - Article
C2 - 22241747
AN - SCOPUS:84864756313
SN - 0903-1936
VL - 40
SP - 470
EP - 478
JO - European Respiratory Journal
JF - European Respiratory Journal
IS - 2
ER -