title: Effect of NYD-SP27 down-regulation on ATP-induced Ca2+-dependent pancreatic duct anion secretion in cystic fibrosis cells.
abstract: Our previous study demonstrated that NYD-SP27 is a novel inhibitory PLC isoform expressed endogenously in human pancreas and upregulated in CFPAC-1 cells. The present study investigated the effect of NYD-SP27 down-regulation on the ATP-stimulated and Ca(2+)-dependent pancreatic anion secretion by CFPAC-1 cell line using short-circuit current (I(SC)) recording. NYD-SP27 antisense-transfected CFPAC-1 (AT-CF) cells exhibited a significantly higher basal transmembrane potential difference and current than those of empty vector-transfected CFPAC-1 (VT-CF) cells. Cl(-) channel blocker, DPC or Glibenclamide (1mM), and inhibitor of Na(+)-K(+)-Cl(-) cotransporter, bumetanide (100 microM) significantly inhibited the basal current in AT-CF cells. The inhibitor of adenylate cyclase, MDL12330A (20 microM), and Ca(2+)-dependent Cl(-) channel (CaCC) blocker, DIDS (100 microM) also significantly reduced the basal current in AT-CF. Apical application of ATP (10 microM) stimulated a fast transient I(SC) increase in VT-CF cells, but a more sustained rise with slower decline in AT-CF cells. Pretreatment with BAPTA-AM (50 microM) reduced the ATP-induced I(SC) response in AT-CF cells by 77.9%. PMA (1 microM), a PKC activator, inhibited the ATP-stimulated current increase (the transient peak) in VT-CF cells, but had no effect on the AT-CF cells. However, PKC inhibitor, staurosporine (40 microM) could inhibit the ATP-induced I(SC) response in AT-CF cells. The present results confirm the previously proposed inhibitory role of NYD-SP27 in the PLC pathway and demonstrate that the suppression of its expression could result in an enhancement of ATP-stimulated Ca(2+) dependent pancreatic anion secretion.
authors.affiliation: Epithelial Cell Biology Research Center, Department of Physiology, Faculty of Medicine, Rm 410, Basic Medical Science Building, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Jin Xia
authors.initials: JX
authors.lastname: Zhu
authors.forename: Ning
authors.initials: N
authors.lastname: Yang
authors.forename: Hu
authors.initials: H
authors.lastname: Zhu
authors.forename: Yiu Wa
authors.initials: YW
authors.lastname: Chung
authors.forename: Hsiao Chang
authors.initials: HC
authors.lastname: Chan
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000838:Anions; D002118:Calcium / Q000502:physiology*; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D003550:Cystic Fibrosis / Q000235:genetics / Q000503:physiopathology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D010183:Pancreatic Ducts / Q000378:metabolism* / Q000503:physiopathology*; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection
chemical_list: D000838:Anions; D008565:Membrane Proteins; C476202:PHF7 protein, human; D014157:Transcription Factors; D000255:Adenosine Triphosphate; D002118:Calcium