Expression of glutathione transferase isoenzymes in the human H295R adrenal cell line and the effect of forskolin.
In previous studies in our laboratory (L. Mankowitz, L. Staffas, M. Bakke, and J. Lund, Biochem J, 1995, 305, 111-118; L. Staffas, L. Mankowitz, M. Söderström, A. Blanck, I. Porsch-Hällström, C. Sundberg, B. Mannervik, B. Olin, J. Rydström, and J.W. DePierre, Biochem J, 1992, 286, 65-72) isoenzymes of GST, primarily of the mu class, have been shown to be downregulated by adrenocorticotropic hormone (ACTH) in rat and mouse adrenal cells. In the present investigation the human adrenal H295R cell line (W.E. Rainey, I.M. Bird, and J.I. Mason, Mol Cell Endocrinol, 1994, 100, 45-50) was examined in a similar manner. Analysis by reverse-phase HPLC revealed that these cells express four isoenzymes of GST, i.e., A1, A2, P1, and M4, as well as another unidentified protein that was retained by our affinity column (elution time of 32 min) and, thus, presumably binds glutathione. Among these forms, A1 was present at the highest level. Upon addition of forskolin (an activator of adenylate cyclase which has been shown previously to mimic the effect of ACTH on adrenal cells) to the culture medium, the level of A1 decreased approximately 70% by forskolin, whereas the levels of the other isoenzymes were slightly increased, and that of the unknown form doubled. Thus, the influence of ACTH on expression of GST isoenzymes in this human adrenal cell line differs from that in rat and mouse adrenal cells.
Stark
Tuula
T
Wallenberg Laboratory, Unit for Biochemical Toxicology, Department of Biochemistry and Biophysics, Stockholm University, S-10691 Stockholm, Sweden. tuula@dbb.su.se
Mankowitz
Louise
L
DePierre
Joseph W
JW
D000311:Adrenal Glands / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D002460:Cell Line; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D005576:Colforsin / Q000494:pharmacology*; D003600:Cytosol / Q000201:enzymology; D005982:Glutathione Transferase / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*
D007527:Isoenzymes; D005576:Colforsin; D005982:Glutathione Transferase