Glucocorticoid-induced lymphocytolysis is not mediated by an induced endonuclease.

摘要: Abstract The mechanism of glucocorticoid-induced internucleosomal DNA cleavage and cytolysis lymphatic cells is not known. Recent data (Compton, M.M., Cidlowski, J.A. (1987) J. Biol. Chem. 262, 8288-8292) suggested that in vivo treatment rat thymocytes with glucocorticoids induces a nucleolytic "lysis gene" product(s) responsible for lymphocytolysis. In this paper, the possibility lymphocytolysis may result from nuclease(s) was examined. Using as model system, we have shown by electrophoretic, enzymatic, amino acid sequence analysis putative nucleases identified recently Compton Cidlowski are fact H1, H1(0), core histones, their gross appearance new histone protein synthesis, but release histone-containing nucleosomes during chromatin breakdown. Evidence presented here shows induced nuclease activity an artifact assay system employed. Because our do support induction nuclease(s), examined might be activation constitutive endogenous endonuclease. We it possible to produce characteristic thymocytes, merely incubating intact nuclei untreated adrenalectomized Ca2+ Mg2+ short period time. However, glucocorticoid-sensitive human CEM-C7 lymphocytes independent calcium uptake. conclude glucocorticoid fragmentation does necessarily require expression endonuclease(s). Also, suggest which controls differs operates lymphocytes.