Effect Of Hypothermia On TLR4/NF-?Bp65 Signal Pathway In Mice With Acute Respiratory Distress Syndrome Induced By Lipopolysaccharide

Objective: To investigate the effect of hypothermia on the expression toll-like receptor 4(TLR4),nuclear factors-?Bp65(NF-?Bp65),tumor necrosis factors-?(TNF-?)in the TLR4/ NF-?Bp65 pathway in mice with acute respiratory distress syndrome(ARDS)induced by Lipopolysaccharide(LPS)inhabition.Methods: 48 male C57BL/6 mice were divided into four groups according to the random number method,the control group(A,n=12),the temperature group(B,n=12),the temperature –uncontrolled group(C,n=12),and hypothermia group(D,n=12).The ARDS model was reproduced by 5 mg/kg LPS intratracheal instillation,while on normal saline was instilled intratracheally for A group.The physical cooling was started after installation.The body temperature was lowered to 33±1? in D group and 36.5±0.5? in B group and no invention was used for C group.The mice were put to death respectively at T0,T8(the temperature reached the target temperature at 0h,8h)and arterial blood gas was determined.After cleaning the lung tissue with the right lung saline,the lung tissue was preserved in 10% of the sexual forest,and paraffin section was carried out in the later stage,and the lung tissue was observed by the light microscope,and the pathological changes were performed in the semi-quantitative grade.Enzyme-linked using enzyme-linked immunosorbent assay(ELISA)to detect serum TNF-?expression,protein Western Blot test(Western Blot)in detection of lung tissue TLR4 and NF-?Bp65 protein expression using SPSS22.0 statistical software for data analysis and processing,with P < 0.05,the difference was statistically significant.Results: after instillation LPS of ARDS,there was no significant change in group A at each time(P<0.05).Compared with group A,the oxygenation index(PaO2/FiO2)was decreased,serum TNF-?content increased obviously,the lung tissue of TLR4 and NF-kappa Bp65 protein expression were significantly increased(P < 0.05).Compared with group B and group C,the PaO2/FiO2 in group D was significantly increased in T8(290.43±1.31 vs 256.35±18.25 vs 263.45±8.65,all P<0.05).In serum,TNF-? decreased significantly in T8(268.34 + 6.31 vs.334.40 + 10.20 vs.310.43 + 11.26,P<0.05).The expression of TLR4 and NF-?Bp65 protein was significantly decreased in T8(TLR4 A value,0.51±0.15 vs 0.92±0.24 vs 0.88±0.21;NF-?Bp65 A value,0.33±0.08 vs 0.57±0.11 vs 0.56±0.10,all P<0.05);There was no difference between group B and group C.Conclusion: hypothermia can down-regulate the expression of TLR4,NF-?Bp65 protein in the TLR4/NF-?Bp65 signal pathway protect lung tissue of mice with ARDS introduced by LPS and inhibit of inflammatory response.