Effect of Mild Hypothermia on the Expression of Toll-like Receptor 2 in Lung Tissues with Experimental Acute Lung Injury

Objective and Design Our study aimed to determine the effect of mild hypothermia (MHT) on the expression of toll-like receptor 2 (TLR2) in lung tissue with acute lung injury. The animals were randomly divided into control, model and mild hypothermia groups. Methods A total of 40 rats was used in the study. Acute lung injury was induced by lipopolysaccharide and MHT was maintained at 32.5∼33.0 °C using body surface ice-bag placement combined with animal thermostat system. The ratio of PaO2 /FiO2 was recorded. The mRNA and protein expressions of TLR2 were measured by real-time polymerase chain reaction and western blotting respectively. Moreover, enzyme linked immunosorbent assay were used for the quantification of TNF-α. Results The ratio of PaO2 /FiO2 was increased by MHT. TLR2 and TNF-α were increased in the rat lung 1 h and 8 h in the rats with acute lung injury while they were significantly decreased by MHT. Histological examination revealed that MHT alleviated the degree of inflammation. Conclusion Our study suggested that MHT might improve the lung function by inhibiting the inflammation via down-regulating the expressions of TLR2 in the acute injury lung tissues.