不同机械牵张应力对大鼠肺泡巨噬细胞HMGB1表达的影响

Effect of different mechanical stretch on HMGB1 expression in rat alveolar macrophage

目的评价不同机械牵张应力对大鼠肺泡巨噬细胞高迁移率族蛋白1（HMGB1）表达的影响。方法雄性SD大鼠，周龄8～12周，体重270～320g，放血处死后，收集支气管肺泡灌洗液，分离、培养和传代肺泡巨噬细胞。将细胞接种于6孔培养板中，细胞浓度10^5／ml，培养48h后，随机分为5组（11=6），对照组（C组）不施加机械牵张应力；S1-4组分别施加5％、10％、15％和20％机械牵张应力，牵张频率30次／min，牵张时间24h。采用RT-PCR法测定HMGB1 mRNA表达；采用Westemblot方法测定HMGB1表达。结果肺泡巨噬细胞给予机械牵张应力后，HMGB1及其mRNA表达随机械牵张应力的增大而上调（P〈0．05或0．01）。结论大鼠肺泡巨噬细胞HMGB1的表达与机械牵张应力呈强度依赖性。

Objective To investigate the effects of different mechanical stretch on expression of high mobility group box 1 protein （HMGB1） in rat alveolar macrophages （AMs）. Methods Male SD rats aged 8-12 weeks weighing 270-320 g were anesthetized and sacrificed by bloodletting. The lungs were lavaged with macrophage isolation buffer. Lavage samples were centrifuged and the AMs were resuspended in RPMI 1640. After being cultured for48 h,AMs were randomly divided into 5 groups（ n = 6 each） and subjected to 0 （group C）, 5% （group S1 ） , 10% （group S2 ） , 15% （group S3 ） and 20% （group S4 ） elongation using Flexercell 4000TM cell stress system for 24 h at frequency of 30 bpm. The expression of HMGB1 mRNA was determined by RT-PCR and expression of HMGBI determined by Western blot. Results The expression of HMGB1 and mRNA in AMs was significantly up-regulated with increasing stretching force （ P 〈 0.05 or 0.01 ）. Conclusion Mechanical stretch up-regulates the expression of HMGB1 and mRNA in rat AMs in a intensity-dependent manner.