The sarcoplasmic–endoplasmic reticulum Ca2+ ATPase 2b regulates the Ca2+ transients elicited by P2Y2 activation in PC Cl3 thyroid cells

Abstract

In PC Cl3 cells, a continuous, fully differentiated rat thyroid cell line, P2Y 2 purinoceptor activation provoked a transient increase of [Ca 2C ] i , followed by a decreasing sustained phase. The a and b1 protein kinase C (PKC) inhibitor Gö 6976 decreased the rate of decrement to the basal [Ca 2C ] i level and increased the peak of Ca 2C entry of the P2Y 2 -provoked Ca 2C transients. These effects of Gö 6976 were not caused by an increased permeability of the plasma membrane, since the Mn 2C and Ba 2C uptake were not changed by Gö 6976. Similarly, the Na C /Ca 2C exchanger was not implicated, since the rate of decrement to the basal [Ca 2C ] i level was equally decreased in physiological and Na C -free buffers, in the presence of Gö 6976. On the contrary, the activity of the sarcoplasmic-endoplasmic reticulum Ca 2C ATPase (SERCA) 2b was profoundly affected by Gö 6976 since the drug was able to completely inhibit the stimulation of the SERCA 2b activity elicited by P2-purinergic agonists. Finally, the PKC activator phorbol myristate acetate had effects opposite to Gö 6976, in that it markedly increased the rate of decrement to the basal [Ca 2C ] i level after P2Y 2 stimulation and also increased the activity of SERCA 2b. These results suggest that SERCA 2b plays a role in regulating the sustained phase of Ca 2C transients caused by P2Y 2 stimulation.

PKC‐ε‐dependent cytosol‐to‐membrane translocation of pendrin in rat thyroid PC Cl3 cells

“…In the present study, we used PC Cl3 cells, which are differentiated thyroid cells sensitive to thyrotropin (TSH) stimulation for their growth (Fusco et al, 1987; Berlingieri et al, 1993) that express the typical markers of thyroid differentiation, such as Tg, thyroperoxidase (TPO), thyrotropin receptor (TSHR) and Na + /I − symporter (NIS). Therefore, this cell line has been used extensively for studying thyroid function, including the detailed study of the thyroid ion transporters (Marsigliante et al, 2002, 2003; Vilella et al, 2003; Ulianich et al, 2004, 2006; Verri et al, 2004). The physiology of PC Cl3 cells, as well as the expression of thyroid‐specific genes, is controlled by hormones such as TSH and insulin (Fusco et al, 1987; Kimura et al, 1999; Trapasso et al, 1999; Villone et al, 2000; Bjorklund et al, 2005).…”

Hypoxia-induced changes in Ca2+ mobilization and protein phosphorylation implicated in impaired wound healing

“…Injured cells release nucleotides that serve as ligands for cell-surface purinergic receptors, and injured neurons release components, including ATP and glutamate, that bind their respective receptors. The release of nucleotides can modulate Ca 2ϩ homeostasis (4,11,43,52,54).Neuronal transmitters such as glutamate bind to metabotropic G protein-coupled receptors or to ionotropic receptors, including 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid (AMPA), kainate, and N-methyl-D-aspartate (NMDA) receptors. It has been reported that epithelial cells do not respond to AMPA or kainate, but they do respond to glutamate in neuronal wound media and to NMDA.…”

“…Injured cells release nucleotides that serve as ligands for cell-surface purinergic receptors, and injured neurons release components, including ATP and glutamate, that bind their respective receptors. The release of nucleotides can modulate Ca 2ϩ homeostasis (4,11,43,52,54).…”

Inhibition of ZL55 cell proliferation by ADP via PKC‐dependent signalling pathway

“…P2YRs have been traditionally credited with growth‐promoting and we and others have shown that P2Y2 and P2Y6 receptors support cell growth in vitro (Elia et al, ; Muscella et al, ; Muscella et al, ; Wagstaff et al, ). We also observed that P2Y2 receptor plays a crucial role in different cellular responses in normal and tumorigenic thyroid cell lines (Elia et al, ; Ulianich et al, ). While P2Y expression and functions in several human tumours are well documented (Burnstock & Di Virgilio, ) no data are so far available in human MPM.…”