Expression and localization of cyclooxygenase isoforms and cytosolic phospholipase A2 in anti-Thy-1 glomerulonephritis.
Glomerular expression of the major rate-limiting enzymes for prostanoid synthesis, cyclooxygenase isoforms (COX-1 and COX-2) and cytosolic phospholipase A2 (cPLA2), was investigated in anti-Thy-1 nephritis in rats. Ribonuclease protection assay demonstrated minimal COX-1 mRNA expression in glomeruli of control rat kidneys and a gradual increase of expression from day 1 to day 10 after administration of monoclonal anti-rat Thy-1 antibody. On the other hand, COX-2 mRNA expression, also minimal in the normal glomeruli, was enhanced in a biphasic pattern with two peaks at 1 h and day 10. Expression of cPLA2 mRNA, which was undetectable in normal glomeruli, was induced on day 1 and increased gradually in a pattern similar to that of COX-1 mRNA expression. Immunofluorescence microscopy, using antibodies against COX isoforms, showed that both COX-1 and COX-2 were negligible or faintly detectable in the glomeruli of control rat kidneys. In contrast, the immunofluorescence for COX-1 was intensified on days 4 and 10 along the glomerular capillary walls probably in glomerular epithelial and/or endothelial cells, whereas COX-2 staining was exclusively enhanced in the glomerular epithelial cells at 1 h and day 10 during the course of anti-Thy-1 nephritis. These findings indicate that prostanoids generated through induction of COX-1, COX-2, and cPLA2 are implicated in the mediation of the mesangial cell injury model. In particular, the upregulation of COX-2 expression in glomerular epithelial cells in the selective mesangial cell injury model suggests an intercellular interaction between mesangial cells, and glomerular epithelial cells.
Hirose
S
S
Department of Pathology, Institute of Nephrology, Niigata, Japan.
Yamamoto
T
T
Feng
L
L
Yaoita
E
E
Kawasaki
K
K
Goto
S
S
Fujinaka
H
H
Wilson
C B
CB
Arakawa
M
M
Kihara
I
I
D000818:Animals; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D003600:Cytosol / Q000201:enzymology; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression / Q000235:genetics; D005921:Glomerulonephritis / Q000201:enzymology* / Q000276:immunology; D007518:Isoantibodies / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology; D007527:Isoenzymes / Q000032:analysis* / Q000235:genetics; D007678:Kidney Glomerulus / Q000737:chemistry / Q000187:drug effects / Q000473:pathology; D008565:Membrane Proteins; D008856:Microscopy, Fluorescence; D010741:Phospholipases A / Q000032:analysis* / Q000235:genetics; D054467:Phospholipases A2; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011921:Rats, Inbred WKY
D007518:Isoantibodies; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; C035678:anti-Thy antibody; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496513:Ptgs1 protein, rat; D010741:Phospholipases A; D054467:Phospholipases A2