title: Neuroprotective effect of calcitriol on ischemic/reperfusion injury through the NR3A/CREB pathways in the rat hippocampus.
abstract: Calcitriol has been demonstrated to provide neuroprotection against ischemia/reperfusion (I/R) injury. However, the exact mechanism of this protection remains unknown. In the present study, the neuroprotective effect of calcitriol was investigated in rats exposed to cerebral I/R injury induced by middle cerebral artery occlusion (MCAO). In addition, the involvement of NR3A, extracellular signal‑regulated kinase 1/2 (ERK1/2), and phosphorylated cAMP/Ca2+‑response element binding protein (p‑CREB) in this protective action was determined in the hippocampal neurons. Western blot analysis was conducted to analyze the protein levels of NR3A, mitogen‑activated protein kinase kinase (MEK) and p‑CREB. The immunoreactivity of p‑CREB and NR3A were measured by quantum dot‑based immunofluorescence analysis. Results showed that MCAO rats exhibited large cortical infarct volumes. By contrast, intraperitoneal administration of calcitriol significantly reduced infarct volumes seven days following reperfusion, and these results were accompanied by elevated NR3A and p‑CREB activity in the hippocampal neurons. The inhibition of MEK by the addition of PD98059 led to attenuation of the neuroprotective effects of calcitriol and a correlated decrease in CREB activity. The results also demonstrated that calcitriol protected the brain from I/R injury through the NR3A‑MEK/ERK‑CREB pathway.
authors.affiliation: Department of Anesthesiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Fu
authors.forename: Rui
authors.initials: R
authors.lastname: Xue
authors.forename: Junfeng
authors.initials: J
authors.lastname: Gu
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiao
authors.forename: Heying
authors.initials: H
authors.lastname: Zhong
authors.forename: Xuelian
authors.initials: X
authors.lastname: Pan
authors.forename: Ran
authors.initials: R
authors.lastname: Ran
mesh_terms: D000818:Animals; D020520:Brain Infarction / Q000150:complications / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D002545:Brain Ischemia / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D002117:Calcitriol / Q000494:pharmacology / Q000627:therapeutic use*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D005419:Flavonoids / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D009929:Organ Size / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D015427:Reperfusion Injury / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D005419:Flavonoids; C464437:NR3A NMDA receptor; D018696:Neuroprotective Agents; D016194:Receptors, N-Methyl-D-Aspartate; D020929:Mitogen-Activated Protein Kinase Kinases; D002117:Calcitriol; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one
keywords: cerebral   ischemia; cAMP/Ca2+-response   element   binding protein; neuroprotection; NR3A; rat