Glucocorticoid protects rodent hearts from ischemia/reperfusion injury by activating lipocalin-type prostaglandin D synthase-derived PGD2 biosynthesis.
Lipocalin-type prostaglandin D synthase (L-PGDS), which was originally identified as an enzyme responsible for PGD2 biosynthesis in the brain, is highly expressed in the myocardium, including in cardiomyocytes. However, the factors that control expression of the gene encoding L-PGDS and the pathophysiologic role of L-PGDS in cardiomyocytes are poorly understood. In the present study, we demonstrate that glucocorticoids, which act as repressors of prostaglandin biosynthesis in most cell types, upregulated the expression of L-PGDS together with cytosolic calcium-dependent phospholipase A2 and COX2 via the glucocorticoid receptor (GR) in rat cardiomyocytes. Accordingly, PGD2 was the most prominently induced prostaglandin in vivo in mouse hearts and in vitro in cultured rat cardiomyocytes after exposure to GR-selective agonists. In isolated Langendorff-perfused mouse hearts, dexamethasone alleviated ischemia/reperfusion injury. This cardioprotective effect was completely abrogated by either pharmacologic inhibition of COX2 or disruption of the gene encoding L-PGDS. In in vivo ischemia/reperfusion experiments, dexamethasone reduced infarct size in wild-type mice. This cardioprotective effect of dexamethasone was markedly reduced in L-PGDS-deficient mice. In cultured rat cardiomyocytes, PGD2 protected against cell death induced by anoxia/reoxygenation via the D-type prostanoid receptor and the ERK1/2-mediated pathway. Taken together, these results suggest what we believe to be a novel interaction between glucocorticoid-GR signaling and the cardiomyocyte survival pathway mediated by the arachidonic acid cascade.
Tokudome
Satori
S
Department of Regenerative Medicine and Advanced Cardiac Therapeutics, School of Medicine, Keio University, Tokyo, Japan.
Sano
Motoaki
M
Shinmura
Ken
K
Matsuhashi
Tomohiro
T
Morizane
Shintaro
S
Moriyama
Hidenori
H
Tamaki
Kayoko
K
Hayashida
Kentaro
K
Nakanishi
Hiroki
H
Yoshikawa
Noritada
N
Shimizu
Noriaki
N
Endo
Jin
J
Katayama
Takaharu
T
Murata
Mitsushige
M
Yuasa
Shinsuke
S
Kaneda
Ruri
R
Tomita
Kengo
K
Eguchi
Naomi
N
Urade
Yoshihiro
Y
Asano
Koichiro
K
Utsunomiya
Yasunori
Y
Suzuki
Takeshi
T
Taguchi
Ryo
R
Tanaka
Hirotoshi
H
Fukuda
Keiichi
K
D000818:Animals; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D005938:Glucocorticoids / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000378:metabolism*; D054834:Lipocalins / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D015428:Myocardial Reperfusion Injury / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010100:Oxygen / Q000378:metabolism; D015230:Prostaglandin D2 / Q000096:biosynthesis*; D051381:Rats; D015398:Signal Transduction
D005938:Glucocorticoids; D054834:Lipocalins; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase; D015230:Prostaglandin D2; D010100:Oxygen