Mild hypothermia attenuates post-resuscitation brain injury through a V-ATPase mechanism in a rat model of cardiac arrest.
Although therapeutic hypothermia is an effective treatment for post-resuscitation brain injury after cardiac arrest (CA), the underlying mechanism remains unclear. Vacuolar H(+)-ATPase (V-ATPase) plays a key role in cellular adaption to a hypoxic environment. This study sought to evaluate the effect of mild hypothermia on V-ATPase and its involvement in neuroprotection after CA. Male Sprague-Dawley rats were subjected to a 6-min CA, resuscitated successfully, and then assigned to either the normothermia (NT) group or the hypothermia (HT) group. Rats were further divided into 2 subgroups based on the time of euthanasia, either 3 or 24 h after CA (NT-3 h, HT-3 h; NT-24 h, HT-24 h). Mild hypothermia was induced following CA and maintained at 33°C for 2 h. Neurologic deficit scores were used to determine the status of neurological function. Brain specimens were analyzed by TUNEL assay, western blotting, and immunohistochemistry. V-ATPase activity was estimated by subtracting total ATP hydrolysis from the bafilomycin-sensitive activity. Mild hypothermia improved the neurological outcome (HT-24 h: 34.3 ± 16.4 vs NT-24 h: 50.3 ± 17.4) and significantly decreased neurocyte apoptosis 24 h after resuscitation. Mild hypothermia significantly increased V0a1 compared to NT-3 h; V0a1 expression was associated with a decrease in the cleaved caspase 3 expression. These findings suggested that mild hypothermia inhibits CA-induced apoptosis in the hippocampus, which may be associated with reduced V-ATPase impairment. These data provide new insights into the protective effects of hypothermia in vivo.
Department of Emergency, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.|Department of Emergency, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
J C
JC
Zhang
Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
W
W
Lu
Department of Emergency, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
X M
XM
Xie
Department of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
H
H
Pan
Department of Emergency, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Z Q
ZQ
Wu
Department of Emergency, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
G T
GT
Yang
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001930:Brain Injuries / Q000209:etiology / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D053148:Caspase 3 / Q000096:biosynthesis; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000235:genetics; D006323:Heart Arrest / Q000150:complications / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D051381:Rats; D012151:Resuscitation; D025262:Vacuolar Proton-Translocating ATPases / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification
D053148:Caspase 3; C512320:v-ATPase subunit a1, rat; D025262:Vacuolar Proton-Translocating ATPases