Critical Care Medicine
Effect of hypothermia on polarization of microglia and TLR4/NF-κB signaling pathway during oxygen-glucose deprivation/restoration
Shan Kaiyue, Xin Miao, Dong Rui, Chen Huailong, Zhang Gaofeng, Liu Wenjie, Wang Mingshan
Published 2022-09-20
Cite as Chin J Anesthesiol, 2022, 42(9): 1098-1102. DOI: 10.3760/cma.j.cn131073.20211115.00916
Abstract
ObjectiveTo evaluate the effect of hypothermia on the polarization of microglia and TLR4/NF-κB signaling pathway during oxygen-glucose deprivation/restoration (OGD/R).
MethodsBV2 microglia were cultured in vitro and divided into 3 groups (n=18 each) using the random number table method: control group (group C), group OGD/R and OGD/R plus hypothermia group (group OGD/R+ HT). Group C was cultured normally for 24 h. In group OGD/R, the cells were exposed to 5% CO2-1% O2 at 37 ℃ for 2 h in a glucose-free medium, followed by restoration of glucose and oxygen for 24 h. In group OGD/R+ HT, the high-glucose medium was replaced with a glucose-free medium, the cells were exposed to 5% CO2-1% O2 for 2 h in a 33 ℃ cryostat, followed by restoration of glucose and oxygen for 24 h. The cell survival rate was measured by CCK-8 assay.The expression of M1 microglia markers CD32 and iNOS protein and mRNA and M2 microglia markers CD206 and Arg-1 and mRNA was detected by immunofluorescence and real-time quantitative polymerase chain reaction.The expression of TLR-4 and NF-κB in cells was detected by Western blot, and the expression of TLR4 and NF-κB mRNA in cells was detected by real-time quantitative polymerase chain reaction.The concentrations of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 10 (IL-10) in the cell supernatant were detected by enzyme-linked immunosorbent assay.
ResultsCompared with group C, the cell survival rate was significantly decreased, the expression of CD32, iNOS, CD206, Arg-1, TLR4 and NF-κB protein and mRNA was up-regulated, and the concentrations of TNF-α, IL-1β and IL-10 in supernatant were increased in OGD/R and OGD/R+ HT groups (P<0.05). Compared with group OGD/R, the cell survival rate was significantly increased, the expression of CD32, iNOS, TLR4 and NF-κB protein and mRNA was down-regulated, the expression of CD206 and Arg-1 protein and mRNA was up-regulated, the concentrations of TNF-α and IL-1β in supernatant were decreased, and the concentration of IL-10 was increased in group OGD/R+ HT (P<0.05).
ConclusionsHypothermia can significantly inhibit microglia polarization toward M1 phenotype, increase microglia polarization toward M2 phenotype and inhibit the development of inflammatory responses during OGD/R, and the mechanism may be related to inhibition of TLR4/NF-κB signaling pathway.
Key words:
Hypothermia, induced; Microglia; Reperfusion injury; Toll-Like receptor 4; NF-kappa B; Polarization
Contributor Information
Shan Kaiyue
Graduate School of Dalian Medical University, Dalian 116044, China
Xin Miao
Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao 266071, China
Dong Rui
Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao 266071, China
Medical School of Nanjing University, Nanjing 210008, China
Chen Huailong
Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao 266071, China
Zhang Gaofeng
Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao 266071, China
Liu Wenjie
Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao 266071, China
Wang Mingshan
Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao 266071, China
