Focal cerebral ischemia/reperfusion injury in mice induces hematopoietic prostaglandin D synthase in microglia and macrophages.
Hematopoietic prostaglandin D synthase is a key enzyme in synthesis of prostaglandin D. Hematopoietic prostaglandin D synthase is expressed in microglia of the developing mouse brain. This study determined the serial changes and cellular localization of hematopoietic prostaglandin D synthase, and its role in cerebral ischemia/reperfusion injury using C57BL/6 mice (n=84) and bone marrow chimera mice (n=16). The latter mice were selected based on their expression of enhanced green fluorescent protein in bone marrow/blood-derived monocytes/macrophages. The middle cerebral artery was occluded for 60 min, followed by reperfusion. Hematopoietic prostaglandin D synthase expression was examined by immunohistochemistry and Western blotting. Hematopoietic prostaglandin D synthase-positive cells were mainly expressed in the peri-ischemic area at 12 h (P<0.05) and 24 h (P<0.001) after reperfusion, while they were mostly found in the transition area at 48-72 h postreperfusion (P<0.001). There was a significant increase in staining intensity as well as number of hematopoietic prostaglandin D synthase-positive cells in the ischemic core at 5-7 (P<0.001) days postreperfusion. Hematopoietic prostaglandin D synthase-positive cells also co-expressed ionized calcium-binding adapter molecule 1, a marker of microglia/macrophages, and cyclooxygenase-2, but not markers of neurons, oligodendrocytes and astrocytes. Until 72 h postreperfusion, many enhanced green fluorescent protein-positive cells were negative for hematopoietic prostaglandin D synthase, but the number of hematopoietic prostaglandin D synthase-enhanced green fluorescent protein coexpressing cells increased significantly at 5-7 days after reperfusion. Our results indicate that hematopoietic prostaglandin D synthase is mainly produced by endogenous microglia until 72 h after reperfusion, but at 7 days after reperfusion, it is also produced by migrating bone marrow/blood-derived macrophages in the ischemic brain tissue. We speculate that hematopoietic prostaglandin D synthase in the brain has different functions during early and late phases of ischemia.
Liu
M
M
Department of Neurology, Juntendo University School of Medicine 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Eguchi
N
N
Yamasaki
Y
Y
Urade
Y
Y
Hattori
N
N
Urabe
T
T
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000201:enzymology* / Q000503:physiopathology; D002545:Brain Ischemia / Q000201:enzymology* / Q000503:physiopathology; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002452:Cell Count; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D051546:Cyclooxygenase 2 / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006410:Hematopoiesis / Q000502:physiology; D019746:Intramolecular Oxidoreductases / Q000378:metabolism*; D054834:Lipocalins; D008264:Macrophages / Q000201:enzymology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins; D017628:Microglia / Q000201:enzymology*; D015230:Prostaglandin D2 / Q000096:biosynthesis; D015427:Reperfusion Injury / Q000201:enzymology* / Q000503:physiopathology; D018183:Transplantation Chimera; D015854:Up-Regulation
C491049:Aif1 protein, mouse; D002135:Calcium-Binding Proteins; D054834:Lipocalins; D008840:Microfilament Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase; D015230:Prostaglandin D2