RAT GST-8-8 IS EXPRESSED PREDOMINANTLY IN MYELOID ORIGIN CELLS INFILTRATING THE GRAVID UTERUS

Previous studies from our laboratory have shown a relatively high expr ession of rGST8-8 in uterine tissues. This GST isozyme displays relati vely high glutathione-peroxidase activity towards lipid-hydroperoxides and towards toxic 4-hydroxyalkenals generated from lipid peroxidation . Since the uterus is a unique organ, subject to oxidative stress due to infiltration by immune effector cells during gestation and because this infiltration is readily identifiable histologically, the studies reported herein were performed to localize the cell specific expressio n of rGST8-8 to determine whether immune effector cells infiltrating t he pregnant rat uterus specifically expressed rGST8-8. A 75 bp end-rad iolabeled cRNA probe was prepared from the full length mGSTA4-4 cDNA f rom the region which is highly homologous with rGST8-8. This cRNA prob e was used for in situ hybridization studies to localize rGST8-8 in sp ecific cell types of gravid rat uterus. Results of these studies indic ate that this GST isozyme is selectively expressed in myeloid origin c ells such as monocytes/macrophages, and neutrophils infiltrating the u terine endometrium and in vascular walls. Selective expression of rGST 8-8 in the myeloid origin cells, which are known to generate higher le vels of reactive oxygen species, suggests that this GST isozyme plays an important role in the protection mechanisms against lipid peroxidat ion. (C) 1997 Elsevier Science Ltd.