Relationship between mechanism of mild hypothermia-induced reduction of neuronal apoptosis during cerebral ischemia-reperfusion and CaMKK2/AMPK signaling pathway in rats
10.3760/cma.j.cn131073-20240605-00318
- VernacularTitle:亚低温减轻大鼠脑缺血再灌注时神经元凋亡的机制与CaMKK2/AMPK信号通路的关系
- Author:
Yuting DAI
1
;
Dandan ZHANG
;
Xueting WANG
;
Gaofeng ZHANG
;
Lixin SUN
;
Mingshan WANG
Author Information
1. 康复大学青岛医院(青岛市市立医院)麻醉科，青岛 266071
- Publication Type:Journal Article
- Keywords:
Hypothermia, induced;
Reperfusion injury;
Brain;
Apoptosis;
Calcium-calmodulin-dependent protein kinase kinas;
AMP-activated protein kinases
- From:
Chinese Journal of Anesthesiology
2025;45(3):358-363
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the relationship between the mechanism of mild hypothermia-induced reduction of neuronal apoptosis during cerebral ischemia-reperfusion (I/R) and calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2)/adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in rats.Methods:Forty SPF male Sprague-Dawley rats, aged 6-8 weeks, weighing 200-250 g, were divided into 5 groups ( n=8 each) using a random number table method: sham operation group (Sham group), cerebral I/R group (IR group), hypothermia + cerebral I/R group (HIR group), hypothermia + cerebral ischemia-reperfusion + solvent group (HIR-DMSO group) and hypothermia + ischemia-reperfusion + CaMKK2 inhibitor STO-609 group (HIR-STO609 group). A global cerebral I/R injury model was established using the four-vessel occlusion method. In HIR group, HIR-DMSO group, and HIR-STO609 group, an ice blanket was used to reduce the body temperature immediately after cerebral ischemia, bringing the core body temperature down to 32.5-33.5 ℃, and rewarming was carried out 4 h later. One hour before developing the model, STO-609 solution 4 μl was injected into the lateral ventricle in HIR-STO609 group, and the equal volume of dimethyl sulfoxide solution was given instead in HIR-DMSO group. At the end of reperfusion, the modified neurological severity score (mNSS) was performed. Then the rats were sacrificed under deep anesthesia, and the hippocampal tissues were taken to observe the pathological results of the hippocampal tissues (using HE staining and Nissl staining) and to determine the apoptosis rate of neurons (by TUNEL method) and expression of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X (Bax), CaMKK2, phosphorylated AMPK (p-AMPK) and AMPK (by Western blot). Results:Compared with Sham group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly increased, the expression of Bax was up-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was down-regulated, and the ratio of p-AMPK/AMPK was decreased in IR group ( P<0.05). Compared with IR group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly decreased, the expression of Bax was down-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was up-regulated, and the ratio of p-AMPK/AMPK was increased in HIR group ( P<0.05). Compared with HIR group, the mNSS and apoptosis rate of neurons in the hippocampal tissues were significantly increased, the expression of Bax was up-regulated, the expression of Bcl-2, CaMKK2 and p-AMPK was down-regulated, the ratio of p-AMPK/AMPK was decreased ( P<0.05), and no significant change was found in the aforementioned parameters in HIR-DMSO group ( P>0.05). Conclusions:Mild hypothermia can inhibit neuronal apoptosis by up-regulating the CaMKK2/AMPK signaling pathway, thus reducing cerebral I/R injury in rats.
