Increased capacity for store regulated calcium influx in U937 cells differentiated by treatment with dibutyryl cAMP.
We have investigated the mechanisms underlying calcium signalling evoked by cross-linking of the high affinity IgG receptor (Fc gamma RI) in populations of the human monocyte-like cell line, U937, following activation of the cells by cytokine treatment, or differentiation to a more macrophage-like state by treatment with dibutyryl cAMP (Bt2cAMP). We have shown previously that a larger and more prolonged entry of external calcium occurs in Bt2cAMP-differentiated cells, although there is a smaller initial release from internal stores in these cells than in those activated by IFN-gamma treatment. In this paper we demonstrate, by use of the endomembrane Ca(2+)-ATPase inhibitor, thapsigargin, that this effect is explained (at least in part) by an enhanced capacity for store regulated entry of calcium in Bt2cAMP-differentiated cells.
Davis
W
W
Physiological Laboratory, University of Cambridge, UK.
Halliwell
E L
EL
Sage
S O
SO
Allen
J M
JM
D000906:Antibodies; D003994:Bucladesine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D004533:Egtazic Acid / Q000031:analogs & derivatives; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism; D016257:Fura-2; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000502:physiology; D007371:Interferon-gamma / Q000494:pharmacology; D007424:Intracellular Fluid / Q000737:chemistry / Q000378:metabolism; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D015388:Organelles / Q000502:physiology; D017452:Receptors, IgG / Q000502:physiology; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin; D013997:Time Factors
D000906:Antibodies; D007074:Immunoglobulin G; D017452:Receptors, IgG; D013729:Terpenes; D004533:Egtazic Acid; D003994:Bucladesine; D019284:Thapsigargin; D007371:Interferon-gamma; C058180:5,5'-dimethyl-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate; D000252:Calcium-Transporting ATPases; D002118:Calcium; D016257:Fura-2