Significance of TLR2 expression in ischemic liver tissue after liver ischemia/reperfusion in mice

Objective To explore Toll like receptor 2 (TLR2) expression after partial liver ischemia/ reperfusion (I/R) in BALB/c mice and its relationship with liver function impairment. Methods All the animals were randomly divided into ischemia/reperfusion injury (I/R) and sham operation (S) groups. Total RNA was extracted from the liver samples and the expression of TLR2 mRNA was analyzed quantitatively by real time PCR method. Membrane protein was extracted, and the expression of TLR2 protein was detected by western blot method. Portal vein serum and plasma were taken for further detection of the levels of alanine aminotransferase (ALT), tumor necrosis factor alpha (TNF α) and endotoxin . Results After 1h of partial liver ischemia and 4 h of reperfusion, the expression of TLR2 mRNA and TLR2 protein were both remarkably upregulated in tissues of ischemic liver lobes in I/R group compared with that in S group (value of TLR2mRNA: 1.06±0.91vs5.08±1.32,P0.01; value of OD: 433.91±25.53vs102.86±13.58, P0.01),as well as the levels of portal vein TNF α and ALT 〔level of TNF α:(112.52±14.41) pg/ml vs (5.96±4.43) pg/ml, P0.01;level of ALT:(848.33±271.37)U/L vs (42.39± 14.75) U/L,P0.01〕 . The levels of endotoxin in portal vein remained constantly below the normal level,and the difference between both groups was not significant (P0.05). Conclusions TLR2mRNA and TLR2 protein expression were upregulated in tissues of ischemic liver lobes after partial I/R injury in mice, and were associated with increased levels of portal vein ALT and TNF α,and impairment of liver function.