Measuring Ca2+ influxes of TRPC1-dependent Ca2+ channels in HL-7702 cells with Non-invasive Micro-test Technique

AIM: To explore the possibility of using the Noninvasive Micro-test Technique (NMT) to investigate the role of Transient Receptor Potential Canonical 1 (TRPC1) in regulating Ca2+ influxes in HL-7702 cells, a normal human liver cell line. METHODS: Net Ca2+ fluxes were measured with NMT a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPC1 were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction. RESULTS: Ca2+ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 mu mol/L noradrenalin and inhibited by 100 mu mol/L LaCl3 (a non-selective Ca2+ channel blocker); 5 mu mol/L nifedipine did not induce any change. Overexpression of TRPC1 caused increased Ca2+ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 mu mol/L LaCl3 did. CONCLUSION: In HL-7702 cells, there is a type of TRPC1-dependent Ca2+ channel, which could be detected via NMT and inhibited by La3+. (C) 2009 The WIG Press and Baishideng. All rights reserved.