title: [Impact of hypothermia on Toll-like receptor 4 mRNA transcription and inflammatory balance of macrophage induced by lipopolysaccharide].
abstract: OBJECTIVE
  To investigate the impact of hypothermia on Toll-like receptor 4 (TLR4) mRNA transcription and downstream inflammatory balance of macrophage induced by lipopolysaccharide (LPS).
  
  
  METHODS
  RAW264.7 mouse macrophage cell line was collected and cultivated in incubator at 37 centigrade or 32 centigrade. The cells in stimulation group were incubated with 10 ng/mL LPS, while normal saline was used instead in control group. The cells culture supernatant was collected at 2, 8, 24 hours to determine the interleukin (IL-1β and IL-10) levels. Total RNA was collected with TRIzol, and TLR4 mRNA transcriptional level was determined by reverse transcription-polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  Under the intervention of LPS, TLR4 mRNA expression in normal temperature group and hypothermia group was increased first followed by a decreasing trend (both P<0.001), and at the same time point, TLR4 mRNA expression (2(-ΔΔCt)) in hypothermia group was lower than that in normal temperature group (2 hours: 9.19 ± 0.57 vs. 10.08 ± 1.02, t=-2.285, P=0.036; 8 hours: 13.58 ± 1.57 vs. 15.24 ± 1.63, t=-2.201, P=0.042; 24 hours: 6.85 ± 1.17 vs. 8.17 ± 1.21, t=2.353, P=0.032). After the administration of LPS, IL-1β and IL-10 levels in both normal and hypothermia group were gradually increased (all P<0.001), and at the same time point, the level of IL-1β in hypothermia group was lower than that in normal temperature group (2 hours: 87.08 ± 29.35 ng/L vs. 110.53 ± 26.58 ng/L, t=1.777, P=0.047; 8 hours: 119.19 ± 49.14 ng/L vs. 173.25 ± 37.21 ng/L, t=2.631, P=0.018; 24 hours: 208.66 ± 53.83 ng/L vs. 346.56 ± 64.30 ng/L, t=4.933, P<0.001), whereas the level of IL-10 of hypothermia group was higher than that in normal temperature group (8 hours: 170.01 ±2 4.90 ng/L vs. 140.02 ± 15.08 ng/L, t=-3.091, P=0.007; 24 hours: 423.10 ± 52.40 ng/L vs. 165.06 ± 31.97 ng/L, t=-12.611, P<0.001). The IL-1β/IL-10 ratio in normal temperature group was gradually increased (F=20.003, P<0.001), and it was decreased gradually in hypothermia group (F=1.811, P=0.185). At the same time point, IL-1β/IL-10 ratio in hypothermia group was lower than that in normal temperature group (2 hours: 0.740 ± 0.214 vs. 0.993 ± 0.256, t=2.275, P=0.037; 8 hours: 0.701 ± 0.363 vs. 1.237 ± 0.455, t=2.763, P=0.014; 24 hours: 0.493 ± 0.292 vs. 2.099 ± 0.428, t=9.299, P<0.001).
  
  
  CONCLUSIONS
  Hypothermia can reduce TLR4 mRNA transcription level of macrophage after the challenge of LPS, and it can relatively lower the level of IL-1β, but a higher level of IL-10 is maintained, thus creating a tendency of anti-inflammation.
authors: Department of Critical Care Medicine, the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, Guangxi, China. Corresponding author: Tang Zhanhong, Email: tangzhanhong139@sina.com.
authors: Shouzhen
authors: S
authors: Wang
authors: Zhanhong
authors: Z
authors: Tang
authors: Juntao
authors: J
authors: Hu
authors: Liangyan
authors: L
authors: Jiang
authors: Xiang
authors: X
authors: Yin
mesh_terms: D000818:Animals; D002460:Cell Line; D007035:Hypothermia; D007249:Inflammation / Q000473:pathology*; D016753:Interleukin-10 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D008070:Lipopolysaccharides; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology*; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D051197:Toll-Like Receptor 4 / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C556062:IL10 protein, mouse; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D012333:RNA, Messenger; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10