Tong Dongyi, Ma Zhongliang, Su Peng, Wang Shuai, Xu Ying, Zhang Li Min, Wu Ziyi, Liu Kun, Zhao Ping
Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, China.
Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China.
Front Cell Neurosci. 2020 Dec 15;14:590577. doi: 10.3389/fncel.2020.590577. eCollection 2020.
The mechanisms by which exposure of the late-stage progenitor cells to the anesthesia sevoflurane alters their differentiation are not known. We seek to query whether the effects of sevoflurane on late-stage progenitor cells might be regulated by apoptosis and/or autophagy.
To address the short-term impact of sevoflurane exposure on granule cell differentiation, we used 5-bromo-2-deoxyuridine (BrdU) to identify the labeled late-stage progenitor granule cells. Male or female rats were exposed to 3% sevoflurane for 4 h when the labeled granule cells were 2 weeks old. Differentiation of the BrdU-labeled granule cells was quantified 4 and 7 days after exposure by double immunofluorescence. The expression of apoptosis and autophagy in hippocampal dentate gyrus (DG) was determined by western blot and immunofluorescence. Western blot for the expression of NF-κB was used to evaluate the mechanism. Morris water maze (MWM) test was performed to detect cognitive function in the rats on postnatal 28-33 days.
Exposure to sevoflurane decreased the differentiation of the BrdU-labeled late-stage progenitor granule cells, but increased the expression of caspase-3, autophagy, and phosphorylated-P65 in the hippocampus of juvenile rats and resulted in cognitive deficiency. These damaging effects of sevoflurane could be mitigated by inhibitors of autophagy, apoptosis, and NF-κB. The increased apoptosis could be alleviated by pretreatment with the autophagy inhibitor 3-MA, and the increased autophagy and apoptosis could be reduced by pretreatment with NF-κB inhibitor BAY 11-7085.
These findings suggest that a single, prolonged sevoflurane exposure could impair the differentiation of late-stage progenitor granule cells in hippocampal DG and cause cognitive deficits possibly via apoptosis activated by autophagy through NF-κB signaling. Our results do not preclude the possibility that the affected differentiation and functional deficits may be caused by depletion of the progenitors pool.
晚期祖细胞暴露于麻醉药七氟醚后其分化改变的机制尚不清楚。我们试图探究七氟醚对晚期祖细胞的影响是否可能受细胞凋亡和/或自噬的调控。
为了研究七氟醚暴露对颗粒细胞分化的短期影响，我们使用5-溴-2'-脱氧尿苷（BrdU）来识别标记的晚期祖细胞颗粒细胞。当标记的颗粒细胞为2周龄时，将雄性或雌性大鼠暴露于3%七氟醚中4小时。暴露后4天和7天，通过双重免疫荧光对BrdU标记的颗粒细胞的分化进行定量。通过蛋白质免疫印迹法和免疫荧光法测定海马齿状回（DG）中细胞凋亡和自噬的表达。使用蛋白质免疫印迹法检测NF-κB的表达以评估其机制。在出生后28 - 33天对大鼠进行莫里斯水迷宫（MWM）试验以检测其认知功能。
暴露于七氟醚会降低BrdU标记的晚期祖细胞颗粒细胞的分化，但会增加幼鼠海马中半胱天冬酶-3、自噬和磷酸化-P65的表达，并导致认知缺陷。七氟醚的这些损伤作用可被自噬、细胞凋亡和NF-κB的抑制剂减轻。自噬抑制剂3-MA预处理可减轻细胞凋亡增加的情况，NF-κB抑制剂BAY 11-7085预处理可减少自噬和细胞凋亡增加的情况。
这些发现表明，单次长时间七氟醚暴露可能损害海马DG中晚期祖细胞颗粒细胞的分化，并可能通过自噬经NF-κB信号通路激活细胞凋亡而导致认知缺陷。我们的结果不排除受影响的分化和功能缺陷可能由祖细胞池耗竭引起的可能性。
