Effect Of Bacterial Lipoprotein On The Expression Of Toll-like Receptor 2, Myeloid Differentiation Factor 88 And Tumor Necrosis Factor-α In THP-1 Cell Line

Effect of bacterial lipoprotein on the expression of Toll-likereceptor 2, myeloid differentiation factor 88 and tumor necrosisfactor-αin THP-1 cell lineObjective To study the effect of bacterial lipoprotein(BLP) on the expression of Toll-like receptor 2(TLR2) and myeloiddifferentiation factor 88(MyD88) and production of TNF-αbystimulating with different ways in THP-1 cell line. Methods HumanTHP-1 cells were stimulated with 10 ng/ml BLP for 24h to achieve BLPtolerance, then stimulated with 1000 ng/ml BLP for 2h. TLR2 andMyD88 protein concentration were detected using Western Blot analysis,while TNF-αwas detected using available ELISA kit. Results Theproduction of TNF-αin THP-1 cells after stimulated with a low-doseBLP and a following high-dose BLP was significant lower than that inTHP-1 cells after stimulated with a high-dose BLP challenge directly,whereas no significant differences in TLR2 and MyD88 expression wasobserved. Conclusion Pretreatment of THP-1 cells with a low-doseBLP induced BLP tolerance, suppressed TNF-αoverexpression, anddifferent doses of BLP had no effect on the expression of TLR2 andMyD88 protein. Effect of sepsis on cardiac function and the protection of BLPtolerance to cardiac function in mice with sepsis.Objective: To observe the effect of sepsis on cardiacfunction of mice and investigate the protection of BLP tolerance tocardiac function in mice with sepsis. Methods: 55 adult, male C57BL/6mice were randomly divided into three groups: shame operation group,sepsis group(sepsis induced by cecal ligation and puncture), BLPtolerance+sepsis group, the ones of shame operation grouppre-operatively as control. At 4 points of 0 hour, 2 hour, 6 hour and 12hour, heart rate (HR), left ventricle shortening fraction (FS) weremeasured by 2D ultrasonometry, and ejection fraction (EF) and cardiacoutput (CO) were calculated respectively for all groups. Contents ofTNF-αin myocardiac homogenate were detected. The expression ofmacrophage in the myocardiac tissue was detected byimmunohistochemistry. Results: HR, FS and EF in shame operationgroup were tending upwards since Oh to 6h,which was higher at 6hcompared with the baseline, and then declined to the baseline at 12h; COdecreased since Oh to 2h, and returned to the baseline level at 12h. Insepsis group,HR and FS increased from 0h to2h, and decreased since 2h.EF increased since 0h and decreased after 6h. CO continuously decreasedsince 0h to the lowest at 12h. HR, FS, EF and CO in BLP tolerance+sepsis group had similar tendency with sepsis group from 0h to 6h, which in former were lower than ones in later (p＜0.05), but tuned up since 6hand significantly higher than sepsis group at 12h (p＜0.05). Theexpression of TLR2 on myocardiac cells and contents of TNF-αinmyocardiac homogenate had no significant change among all groups.Macrophagic infiltration to myocardiac tissue were observed at 12h insepsis group and 2h in BLP tolerance+sepsis group respectively, the restwere negative. Conclusion: Operation affects cardiac function in mice;sepsis markedly suppress cardiac function; BLP tolerance has theprotection to cardiac function in mice with sepsis; The change in cardiacfunction at early stage of sepsis may have no relationship withinflammation in myocardiac cell.