Expression of cerebral Kuppel-like factor 2 in focal cerebral ischemia-reperfusion injury in rats and intervention effect of nuclear factor kappa B inhibitor / 中国脑血管病杂志

ABSTRACT

Objective To investigate the expression of Kuppel-like factor 2( KLF2 )after focal cerebral ischemia-reperfusion( I/R)injury in rats and the intervention effect of nuclear factor kappa B ( NF-κB)inhibitor. Methods Sixty healthy male SD rats were randomly divided into a sham operation group,an I/R group,and a NF-κB inhibitor group( n=20 in each group). A focal cerebral I/R model was induced by the intraluminal suture method,and NF-κB inhibitor( pyrrolidinedithio carbamate,PDTC)was given to intervene. The observation time points were 6,12,24,and 48 hours after I/R. Reverse transcription-polymerase chain reaction(PCR)and Western blot were used to measure KLF2 mRNA and protein expression in ischemic brain tissue. Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of serum tumor necrosis factorα( TNF-α),and they were compared among groups. Results Compared with the sham operation group,the expression levels of KLF2 mRNA and protein in I/R group in the ischemic brain tissue at each time point were averagely decreased( the relative expression levels of KLF2 mRNA0. 46 ± 0. 03 vs. 0. 82 ± 0. 04,0. 30 ± 0. 04 vs. 0. 78 ± 0. 05,0. 18 ± 0. 04 vs. 0. 76 ± 0. 02,0. 26 ± 0. 02 vs. 0. 81 ± 0. 04,respectively;the relative expression levels of KLF2 protein0. 46 ± 0. 04 vs. 0. 80 ± 0. 02,0. 30 ± 0. 02 vs. 0. 79 ± 0. 02,0. 15 ± 0. 02 vs. 0. 77 ± 0. 01,0. 24 ± 0. 01 vs. 0. 79 ± 0. 02,respectively). They reached the lowest values at 24 hours after I/R,while the serum TNF-αlevels were increased. There were significant differences(all P<0. 05). After giving NF-κB inhibitor PDTC,the expression levels of KLF2 mRNA and protein at 6,12,24,and 48 hours after I/R were upregulated differently compared with the I/R group. The relative expression levels of KLF2 mRNA were 0. 61 ± 0. 04,0. 44 ± 0. 03,0. 34 ± 0. 02,and 0. 43 ± 0. 04, respectively. Those of KLF2 protein were 0. 60 ± 0. 02,0. 43 ± 0. 02,0. 33 ± 0. 01,and 0. 44 ± 0. 03, respectively,while the levels of TNF-αwere decreased. There were significant differences(all P<0. 05). There was a negative correlation between the KLF2 mRNA levels and the serum TNF-αlevels at each time point in the I/R group and the PDTC group( r= —0. 728 ,P<0. 05 ). Conclusions The expression levels of KLF2 mRNA in brain tissue are decreased after I/R,and it is negatively correlated with the serum TNF-α levels. It may be involved in the pathological process of I/R by NF-κB pathway mediated inflammatory reaction.