['To investigate an interaction between the calcium and sulphide signalling pathways, particularly effects of the slow H2 S release donor morpholin-4-ium-4-methoxyphenyl-(morpholino)-phosphinodithioate (GYY4137) on the expression of inositol 1,4,5-trisphosphate receptors (IP3 R) with the possible impact on the apoptosis induction in HeLa cells.', "Gene expression, Western blot analysis, apoptosis determination by Annexin-V-FLUOS and drop in mitochondrial membrane potential by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC1) and immunofluorescence were used to determine differences in control and GYY4137-treated HeLa cells.", 'In HeLa cell line, GYY4137 (10 μm) up-regulated expression of the IP3 R1 and IP3 R2, but not IP3 R3 on both mRNA and protein levels. Concurrently, cytosolic calcium increased and reticular calcium was depleted in concentration-dependent manner, partially by the involvement of IP3 R. Depletion of calcium from reticulum was accompanied by increase in endoplasmic reticulum (ER) stress markers, such as X-box, CHOP and ATF4, thus pointing to the development of ER stress due to GYY4137 treatment. Also, GYY4137 treatment of HeLa cells increased the number of apoptotic cells.'] Does sulphide signalling potentiate apoptosis through the up-regulation of IP3 receptor types 1 and 2?