title: Nicotinamide attenuates the injury-induced decrease of hippocalcin in ischemic brain injury.
abstract: Nicotinamide is an important cofactor in the prevention of brain damage during focal cerebral ischemia. Hippocalcin is a calcium buffer protein that modulates intracellular calcium concentration and attenuates apoptosis. In this study, we investigated whether nicotinamide modulates hippocalcin expression during cerebral ischemia. Male Sprague-Dawley rats were treated with vehicle or nicotinamide (500 mg/kg) 2 h after the onset of middle cerebral artery occlusion (MCAO) and cerebral cortex tissues were collected 24 h after MCAO. Nicotinamide treatment decreased infarct volume in the cerebral cortex of MCAO-operated animals. Our proteomic approach revealed a decrease in hippocalcin expression in vehicle-treated animals during MCAO, which was attenuated by nicotinamide treatment. We used RT-PCR and Western blot analyses to demonstrate that nicotinamide clearly restored the injury-induced decrease in hippocalcin expression. Glutamate toxicity also decreased hippocalcin levels in cultured hippocampal cells, while nicotinamide treatment prevented the glutamate exposure-induced decrease in hippocalcin levels. These results suggest that nicotinamide modulates hippocalcin expression in cerebral ischemic injury and consequently contributes to the prevention of neuronal cell death.
authors.affiliation: Department of Anatomy, College of Veterinary Medicine and Research Institute of Life Science, Gyeongsang National University, Jinju, South Korea. pokoh@gnu.ac.kr
authors.forename: Phil-Ok
authors.initials: PO
authors.lastname: Koh
mesh_terms: D000818:Animals; D015536:Down-Regulation / Q000187:drug effects; D051597:Hippocalcin / Q000378:metabolism*; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D018696:Neuroprotective Agents / Q000627:therapeutic use; D009536:Niacinamide / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome
chemical_list: D018696:Neuroprotective Agents; D051597:Hippocalcin; D009536:Niacinamide