Involvement of phospholipase C in Yersinia enterocolitica heat stable enterotoxin (Y-STa) mediated rise in intracellular calcium level in rat intestinal epithelial cells.
In response to Yersinia enterocolitica heat stable enterotoxin (Y-STa) intracellular calcium level was increased with a prolong sustained phase in presence of calcium chloride in extracellular environment in rat intestinal epithelial cells. Chelation of extracellular calcium with EGTA (extracellular calcium chelator) and suspension of cells in calcium free buffer demonstrated a rapid but transient rise in calcium level, which suggested that Y-STa induced rise in intracellular calcium concentration was the combination of both intracellular calcium store depletion and calcium influx from extracellular environment. Moreover, in response to Y-STa phosphoinositide specific phospholipase C activity and inositol tri phosphate (IP3) level was increased and U73122, a phospholipase C inhibitor could completely inhibit Y-STa induced calcium rise. However, treatment of rat enterocytes with dantrolene IP3, a mediated calcium release inhibitor from intracellular store resulted partial inhibition of Y-STa induced rise in intracellular calcium level. Similar observation was noted with IP3 receptor antagonist 2ABP (2-amino-ethoxydiphenylborate). These results suggested that beside phospholipase C IP3 pathway, phospholipase C might have an independent role in Y-STa induced calcium influx. Rise in phospholipase Cgamma isoform activity in response to Y-STa suggested that gamma isoform of phospholipase C might have a role in Y-STa mediated rise in intracellular calcium level.
Saha
Subhrajit
S
Pathophysiology Division, National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme-XM, Beliaghata, Calcutta 700010, India.
Gupta
Dyuti Dutta
DD
Chakrabarti
Manoj K
MK
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D002478:Cells, Cultured; D003620:Dantrolene / Q000494:pharmacology; D004768:Enterotoxins / Q000494:pharmacology*; D004963:Estrenes / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors; D013997:Time Factors; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015008:Yersinia enterocolitica / Q000201:enzymology / Q000502:physiology*
D001427:Bacterial Toxins; D001896:Boron Compounds; D015220:Calcium Channels; D004768:Enterotoxins; D004963:Estrenes; D053496:Inositol 1,4,5-Trisphosphate Receptors; D011760:Pyrrolidinones; D018160:Receptors, Cytoplasmic and Nuclear; C048669:heat-stable enterotoxin (Yersinia); C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D015544:Inositol 1,4,5-Trisphosphate; C109986:2-aminoethoxydiphenyl borate; D010738:Type C Phospholipases; D003620:Dantrolene; D002118:Calcium