Nitric oxide (NO) production and Ca2+ homeostasis are key determinants for the control of many cell functions. NO is known to be a mediator of Ca2+ homeostasis in a highly complex and cell-specific manner and although Ca2+ homeostasis has been explored in human oral cancer cells, the exact mechanisms are not completely understood. In this study we investigated the impact of exogenous NO on [Ca2+]c homeostasis in PE/CA-PJ15 cells. DESIGN: Cells were treated with S-nitrosocysteine as NO-donor and the determinations of cytosolic Ca2+ concentrations were performed using FURA-2 AM. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) and oligomycin were used to challenge mitochondrial functionality, whereas thapsigargin (TG) and La3+ were employed to perturb intracellular calcium levels. RESULTS: NO derived from S-nitrosocysteine (CySNO) induced a dose-dependent reduction of cytosolic calcium [Ca2+]c whereas oxy-haemoglobin (oxyHb) completely counteracted this effect. Subsequently, we assessed possible relationships between NO and cellular structures responsible for Ca2+ homeostasis. We found that uncoupling of mitochondrial respiration with carbonyl-cyanide-4-(trifluoromethoxy)-phenylhydrazone (FCCP) and oligomycin strongly reduced the effect of NO on [Ca2+]c. Moreover, we found that during this mitochondrial energetic deficit, the effect of NO on [Ca2+]c was also reduced in the presence of La3+ or thapsigargin. CONCLUSIONS: NO induces a concentration-dependent [Ca2+]c reduction in PE/CA-PJ15 human oral cancer cells and potentiates mitochondrial Ca2+ buffering in the presence of TG or La3+. Further, we show that exogenous NO deregulates Ca2+ homeostasis in PE/CA-PJ15 cells with fully energized mitochondria.
Tiribuzi, R., Tartacca, F., Aisa, M., Cerulli, G. G., Palmerini, C., The impact of nitric oxide on calcium homeostasis in PE/CA-PJ15 cells., <<ARCHIVES OF ORAL BIOLOGY>>, 2014; 59 (Agosto): 1377-1383. [doi:10.1016/j.archoralbio.2014.07.022] [http://hdl.handle.net/10807/60739]
The impact of nitric oxide on calcium homeostasis in PE/CA-PJ15 cells.
Cerulli, Giuliano Giorgio;
2014
Abstract
Nitric oxide (NO) production and Ca2+ homeostasis are key determinants for the control of many cell functions. NO is known to be a mediator of Ca2+ homeostasis in a highly complex and cell-specific manner and although Ca2+ homeostasis has been explored in human oral cancer cells, the exact mechanisms are not completely understood. In this study we investigated the impact of exogenous NO on [Ca2+]c homeostasis in PE/CA-PJ15 cells. DESIGN: Cells were treated with S-nitrosocysteine as NO-donor and the determinations of cytosolic Ca2+ concentrations were performed using FURA-2 AM. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) and oligomycin were used to challenge mitochondrial functionality, whereas thapsigargin (TG) and La3+ were employed to perturb intracellular calcium levels. RESULTS: NO derived from S-nitrosocysteine (CySNO) induced a dose-dependent reduction of cytosolic calcium [Ca2+]c whereas oxy-haemoglobin (oxyHb) completely counteracted this effect. Subsequently, we assessed possible relationships between NO and cellular structures responsible for Ca2+ homeostasis. We found that uncoupling of mitochondrial respiration with carbonyl-cyanide-4-(trifluoromethoxy)-phenylhydrazone (FCCP) and oligomycin strongly reduced the effect of NO on [Ca2+]c. Moreover, we found that during this mitochondrial energetic deficit, the effect of NO on [Ca2+]c was also reduced in the presence of La3+ or thapsigargin. CONCLUSIONS: NO induces a concentration-dependent [Ca2+]c reduction in PE/CA-PJ15 human oral cancer cells and potentiates mitochondrial Ca2+ buffering in the presence of TG or La3+. Further, we show that exogenous NO deregulates Ca2+ homeostasis in PE/CA-PJ15 cells with fully energized mitochondria.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.