Chloride transport in NCL-SG3 sweat gland cells: channels involved.
The aim of the study was to assess whether NCL-SG3, the only immortalized sweat gland cell line available, can be used as an in vitro model to study chloride ion transport in cultured sweat gland cells. Cl(-) efflux was measured using the MQAE dye fluorescence technique after stimulating the cells with different agonists. A significant stimulation of chloride efflux was achieved with the calcium ionophore A23187 resulting in an efflux rate of 0.9 mM/s. Both ATP and UTP activated chloride efflux in these cells, with the ATP response being larger. IBMX and forskolin stimulation did not induce a rate of chloride efflux above the basal level. Immunocytochemistry showed no detectable CFTR in NCL-SG3 cells. This finding was confirmed with flow cytometry analysis. Niflumic acid (20 and 100 microM NFA) and 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid (H2DIDS) (100 ìM) decreased the rate of ATP-stimulated chloride efflux significantly (0.40 and 0.31 mM/s with NFA, 0.37 mM/s with H2DIDS). Gadolinium (20 ìM) had no effect on the chloride transport rate. In conclusion, the NCL-SG3 cells retain some of the aspects of human sweat gland epithelium, such as the ability to form cell-cell contacts. The CFTR protein is neither functional nor expressed in cultured NCL-SG3 sweat gland cells. Ca(2+)-activated chloride conductance is confirmed and the putative Ca(2+)-activated chloride channel (CaCC) is further characterized in term of its pharmacological sensitivity. The NCL-SG3 sweat gland cell line can be used to investigate the characteristics of the CaCC and to identify the channel.
Servetnyk
Z
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Department of Medical Cell Biology, Uppsala University, Box 571, SE-751 23 Uppsala, Sweden. janna.servetnyk@mcb.uu.se
Roomans
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GM
D015415:Biomarkers; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D018118:Chloride Channels / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D015640:Ion Channel Gating; D017136:Ion Transport; D046529:Microscopy, Electron, Transmission; D013545:Sweat Glands / Q000378:metabolism* / Q000648:ultrastructure
D015415:Biomarkers; D018118:Chloride Channels; D002712:Chlorides; D002118:Calcium