[Changes of proto-oncogene expression and cytosolic free calcium in activited T-lymphocytes of aged mice].
Dot blot showed that the expression of proto-oncogene c-fos was inhibited in lymphocytes from old mice (20-24 months). In order to measure the effect of aging on signal transduction, we separated T cells by passage of spleen lymphocytes through long nylon fiber columns. Con A-induced [3H] TdR incorperation in cells from old mice was lower than that from young mice (2 months). The maximum level of [3H]TdR incorperation of old mouse T cells was only 22% of that of young mouse T cells. When T cells were stimulated with the combination of a phorber ester (PMA) and a calcium ionophore (ionomycin), [3H]TdR incorperation remained depressed in old mouse T cells. Further, cytosolic free calcium level was measured by monitoring fluoresence intensity in fura-2/AM loaded T cells. At 10 minutes after con A stimulation, the concentration of cytosolic free calcium ([Ca2+]) in old mouse T cells elevated to 273 x 10(-9)mol/L, while [Ca2+] in young mouse T cells markedly increased to 637 x 10(-9)mol/L. When T cells were stimulated with the combination of PMA and ionomycin, at 7 minutes, [Ca2+] in old mouse T cells elevated to 790 x 10(-9)mol/L, while [Ca2+] in young mouse T cells markedly increased up to 2190 x 10(-9)mol/L.
Ran
Q
Q
Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing.
Li
D
D
Zhen
Y
Y
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D015870:Gene Expression; D016762:Genes, fos; D015759:Ionomycin; D051379:Mice; D008810:Mice, Inbred C57BL; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D015759:Ionomycin; D002118:Calcium