胆红素对新生儿脐血单核细胞表面分子Toll样受体4的影响

Effect of bilirubin on expression of toll-like receptor 4 in cord blood monocytes

摘要:

目的：探讨不同浓度胆红素对新生儿脐血单核细胞（CBMC）表面分子Toll样受体4（TLR4）的影响。方法：采用纤维连接蛋白结合法分离得到CBMC，将其加入含不同浓度胆红素（0~307.8 μmol/L）的牛血清白蛋白溶液中孵育1 h，再加入脂多糖（LPS，1 μg/mL）刺激24 h。收集CBMC，采用间接免疫荧光技术检测细胞表面分子TLR4的表达。结果：胆红素浓度为102.6、153.9、 220.6和307.8 μmol/L时，CBMC表面分子TLR4 的表达率均明显降低，随着胆红素浓度的升高，这种降低趋势越明显。结论：胆红素抑制CBMC表面分子TLR4的表达，随着胆红素浓度的升高，抑制作用越明显。

Abstract:

OBJECTIVE: To study the effect of different concentrations of bilirubin on expression of toll-like receptor 4 (TLR4) in cord blood monocytes (CBMC). METHODS: Under the sterile condition, umbilical vein blood samples were obtained from normal full-term newborns, and the monocytes were in vitro separated by the method of gelatin/plasma coated flasks. The monocytes were preincubated with various concentrations (0-307.8 μmol/L) of bilirubin dissolved in bovine albumin solution for 1 hr. Bilirubin-treated CBMC were further cultured with LPS (1 μg/mL) to induce cellular activation for 24 hrs, and then the CBMC were collected. The expression of TLR4 in monocytes was measured by indirect immunofluorescence method. RESULTS: Bilirubin at the concentrations of 102.6, 153.9, 220.6 and 307.8 μmol/L inhibited the expression of TLR4 of CBMC. The inhibition effect increased with the increasing concentration of bilirubin. CONCLUSIONS: Bilirubin can inhibit the TLR4 expression of CBNC in a dose-dependent manner.