Involvement of PKC-α in regulatory volume decrease responses and activation of volume-sensitive chloride channels in human cervical cancer HT-3 cells

Cheng Yang Chou, Meng Ru Shen, Kuei Sen Hsu, Hsueh Yin Huang, Hui Chuan Lin

研究成果: Article同行評審

31 引文 斯高帕斯(Scopus)

摘要

1. The present study was carried out to identify the specific protein kinase C (PKC) isoform involved in regulatory volume decrease (RVD) responses, and to investigate the signal transduction pathways underlying the activation of volume-sensitive chloride channels in human cervical cancer HT-3 cells. The role of Ca2+ in RVD and in the activation of chloride currents was also studied. 2. The time course of RVDs was prolonged by microinjection of PKC-α antibody but not by PKC-β or PKC-γ antibody, and also by exposure to Ca2+-free medium, in particular when combined with microinjection of EDTA. Immunofluorescence staining showed that hypotonic superfusion evoked the translocation of PKC-α to the cell membrane, whereas PKC-β or PRC-γ remained unaffected. The translocation of PKC-α was observed a few minutes after hypotonic stress, reaching peak intensity at 30 min, and returned to the cytoplasm 60 min after hypotonic exposure. Western blot analyses showed an increased PKC-α level in terms of intensity and phosphorylation in the cell membrane, while neither PKC-β nor PKC-γ was activated upon hyposmotic challenge. 3. Whole-cell patch-clamp studies demonstrated that neomycin and PKC blockers such as staurosporine and H7 inhibited volume-sensitive chloride currents. The inhibitory effect of neomycin on chloride currents can be reversed by the PKC activator phorbol 12-myristate, 13-acetate (PMA). Moreover, the PKC inhibitor and PKC-α antibody, but not PKC-β or PKC-γ antibody, significantly attenuated the chloride currents. The activation of volume-sensitive chloride currents were insensitive to the changes of intracellular Ca2+ but required the presence of extracellular Ca2+. 4. Our results suggest the involvement of PKC-α and extracellular Ca2+ in RVD responses and the activation of volume-sensitive chloride channels in HT-3 cells.

原文English
頁(從 - 到)435-448
頁數14
期刊Journal of Physiology
512
發行號2
DOIs
出版狀態Published - 1998 十月 15

All Science Journal Classification (ASJC) codes

  • Physiology

指紋 深入研究「Involvement of PKC-α in regulatory volume decrease responses and activation of volume-sensitive chloride channels in human cervical cancer HT-3 cells」主題。共同形成了獨特的指紋。

引用此