目的:在妊娠过程中,胎盘可能暴露于多种病原微生物,威胁胎儿正常生长发育。为探讨人胎盘绒毛组织是否表达AIM2炎性体成员基因以及人胎盘组织的AIM2炎性体的活化形式。方法:以THP-1细胞来源的RNA和蛋白作为阳性对照,分别应用RT-PCR和Western blot方法检测人早孕期胎盘绒毛组织中AIM2炎性体两个相关基因AIM2和ASC的表达。分离和体外培养人胎盘绒毛膜组织,并用不同浓度的poly(d A:d T)进行转染,处理24小时后,分别收集组织培养上清和蛋白裂解液,Western blot检测蛋白裂解液中caspase-1的活化,ELISA检测培养上清中IL-1β的分泌。结果:RT-PCR和Western blot结果均显示人早孕期胎盘绒毛组织组成性表达AIM2炎性体相关基因AIM2和ASC。同时,体外培养的人胎盘绒毛组织在转染5μg/m L poly(d A:d T)后,caspase-1剪切片段p10显著增多,培养上清中IL-1β分泌也显著增多(P〈0.01)。结论:人胎盘绒毛组织存在功能性的AIM2炎性体,能够被胞内双链DNA活化。
Objective: During pregnancy, the placenta may become exposed to microorganisms, which may pose a potential threat to the embryo/fetus well-being. This study was preformed to investigate expression and function of the AIM2 inflammasome in human placental villi. Methods: The expression of AIM2 and ASC, two components of the AIM2 inflammasome, were determined in human placental villi by RT-PCR and Western blot. RNA and protein from THP-1 cells were used as positive control. Human placental villi were isolated and cultured in vitro, then transfected with different doses ofpoly (dA:dT) for 24 hours. The supernatant were collected for analysis of 1L-1β secretion and tissue lysates were harvested for detection of caspase-1 activation by Western blot. Results: RT-PCR and Western blot analysis showed that ASC and AIM2 were constitutively expressed in human placental villi. Furthermore, treatment with 5 μg/mL poly (dA:dT) markedly induced IL-1β release and increased caspase-1 activity. Conclusion: The AIM2 inflammasome is expressed and may plays an important role in human placental villi, which is activated by cytosolic double-stranded DNA stimulation.