EXPRESSION OF HUMAN GROUP-II PHOSPHOLIPASE A(2) IN TRANSGENIC MICE

Group II phospholipase A(2) (PLA2) has been proposed to play an import ant role in inflammation and defense against bacterial infection. We i nvestigated tissues of transgenic mice expressing the human group ii P LA2 gene by immunohistochemistry using rabbit anti-human group II PLA2 antibodies, and by in situ hybridization by probing with human group II PLA2 mRNA anti-sense (test) and sense (control) riboprobes. By immu nohistochemistry, human group II PLA2 was found in various mouse tissu es and cell types including hepatocytes, proximal tubule cells of the kidney, epithelial cells of the renal pelvis, urinary bladder and uret er, granulosa cells of Graafian follicles, aortic intima and media, ca rtilage, epiphyseal bone, bronchial epithelial cells, and connective t issue cells in the dermis. By in situ hybridization, group II PLA2 mRN A was localized in hepatocytes, epidermal cells, dermal cells, connect ive tissue fibroblasts, epithelial and smooth muscle cells of the urin ary bladder, and cells of Bowman's capsule. These results show that hu man group II PLA2 is expressed in large amounts in hepatocytes and man y extrahepatic tissues of the transgenic mice. These animals provide a useful new tool for studies on the metabolism, in vivo effects, and p hysiological and pathological roles of phospholipase A(2).