The Effects Of Nucleolin On The Release Of IL-1β Induced By LPS

Sepsis,an infection-caused systemic inflammatory response syndrome(SIRS),is often accompanied by major surgery,trauma,bum and shock,will lead to multiple organ dysfunction syndrome(MODS) that results in a great deal of death.It is believed that the activation of immune systems by LPS may be important in the pathogenesis of sepsis in spite of its unknown mechanism.Nucleolin is a main phosphorylated protein in the nucleus.Its functions have been found to be involved in rRNA transcription, ribosome biogenesis and maturation.It has recently been discovered that nucleolin plays an important role in the processes of HCV duplication, HIV and Para influenza virus invasion and gene-transfer control. However,whether and how nucleolin participates in sepsis is unclear.In this article,the function of nucleolin was studied.Western blot and ELISA were used to defect the expression of nucleolin and interleukin-1β(IL-1β)respectively.Results are as follows:in RAW264.7 cells and mouse lung tissues nucleolin displayed two bands,with one in size 110kD,and the other 80kD.In RAW264.7 cells treated with 500ng/ml of LPS,the 110kD component was increased from 6h to 36h while the 80kD component was decreased at the same time compared with the untreated cells.The similar experimental results were obtained in lung tissues in the mice with endotoxemia.In nuleolin-overexpreed RAW264.7 cells transfected with pcDNA3.1-C23,LPS-induced release of interleukin-1β(IL-1β)was higher than that in pcDNA3.1 empty vector transfected cells.While in nucleolin-inhibited RAW264.7 cells by transfection with antisense oligonucleotide,LPS-induced release of interleukin-1β(IL-1β)was lower than that in normal cells.In conclusion,the 110kD component of nucleolin increased greatly while 80kD component decreased in LPS-induced inflammatory response of RAW264.7 cells and endotoxemia in mice.At the same time, overexpression of the 110kD component of nucleolin could significantly increase the release of interleukin-1β(IL-1β)from RAW264.7 cells,vice versa.