Résumé
microRNAs combined with specific mRNAs are 19-25 nucleotide-long small-molecule RNA that mediate sequence-dependent post-transcriptional gene expression.Accumulating evidences indicate that microRNAs target critical signal transduction molecules of immune system,and involve in regulation of immune tolerance.Recently,microRNAs have been a potential biomarker,and are widely useded in diagnosis and prognosis of cancer,infectious disease,autoimmune disease,and transplantation.If we can further identify regulatory mechanism of microRNAs and their target genes,which makes possible the successful induction of immune tolerance and exert a huge push on organ transplantation.
Résumé
AIM: To observe the changes of interleukin1 receptor associated kinase-4(IRAK-4) in ischemia/reperfusion(I/R) liver pretreated with lipopolysaccharide(LPS) and to explore the protective mechanisms of LPS pretreatment against hepatic I/R injury.METHODS: Male Sprague-Dawley rats,weighing 240-280 g,were divided into three groups: control,ischemia/reperfusion group(I/R group) and LPS-pretreated group(LPS group).On the first day,LPS group received 0.1 mg/kg LPS via the tail vein,followed by 0.5 mg/kg on the 2nd,3rd,4th and 5th day.I/R group received the equivalent volumes(0.5 mL) of sterile PBS.Experiments of I/R injury was induced by temporary ischemia of the left lateral liver lobe for 90 min followed by 3 h reperfusion on 2 days after the last LPS treatment.At 0 min,60 min and 180 min after reperfusion,the expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blotting.The activity of NF-?B and the serum TNF-? level were also detected by ELISA.RESULTS: Although the level of IRAK-4 gene and protein were higher in the LPS group than that in I/R group and control group(P0.05) at 0 min after reperfusion.However,all those indexes were evidently lower in the LPS group than those in I/R group(P