Lin28B/KiSS-1轴对滋养细胞浸润时序化调控的机制研究

Shallow trophoblast invasion results in preeclampsia, and the invasion is strictly regulated. As an important heterochronic gene, Lin28 is involved in cell migration and invasion. Lin28 can regulate the expression of target mRNA at post-transcriptional level by recognizing and binding to specific sequence. Our previous studies indicate that the Lin28 human homolog -Lin28B is stage-specifically expressed in placental tissue, and expression level of Lin28B is related with the state of trophoblast invasion and significantly down-regulated in preeclampsia, which suggested that Lin28B is crucial in stage-specific regulation of trophoblast invasion. After transfection of Lin28B into trophoblast cell line, KiSS-1, which play an inhibition role in trophoblast invasion, is down-regulated in protein level without any change of mRNA level. The KiSS-1mRNA contains the regulation sequences of Lin28B, so we deduce that Lin28B and its downstream gene KiSS-1 might compose of Lin28B/KiSS-1 axis, which regulate stage-specific trophoblast invasion. The aims of this project : ① To investigate the role of Lin28B/KiSS-1 axis in stage-specific regulation of trophoblast invasion during normal pregnancy and preeclampsia. ② To explore the mechanism of Lin28B regulate KiSS-1 in post-transcriptional level, by ribonucleoprotein co-immunoprecipitation, in vitro translation-UV crosslinking and competition assays, etc. ③ Transferring lentiviral-Lin28B plasmid into preeclampsia animal models which trophoblst invasion is shallow, identify the effects of Liin28B on the shallow invasion of trophoblast and explore the mechanism. This study will elucidate the pathogenesis of preeclampsia and provide the new target of prevention and treatment.

滋养细胞浸润不良是导致子痫前期重要原因，浸润受到严格的调控。Lin28作为重要的时序调控因子参与细胞迁移和侵袭，对mRNA起转录后调控作用。前期研究发现人类Lin28B在胎盘组织中表达呈时序性，与滋养细胞浸润状态有关，在子痫前期明显下调，提示Lin28B对滋养细胞浸润起时序化调控作用；转染Lin28B后，滋养细胞浸润抑制基因KiSS-1蛋白水平降低而mRNA不受影响，且KiSS-1mRNA含Lin28B调控序列，推测Lin28B通过调控下游基因KiSS-1组成调控轴对滋养细胞浸润进行时序化调控。本项目拟采用核糖核蛋白免疫共沉淀、体外翻译-紫外交联等方法，探讨Lin28B/KiSS-1轴对正常妊娠和子痫前期滋养细胞浸润的时序化调控及转录后调控机制；构建Lin28B慢病毒载体转入前期构建成功的子痫前期动物模型，验证Lin28B对滋养细胞浸润不良的逆转作用，阐明子痫前期发病机制及提供新的防治靶点

滋养细胞浸润受到严格的调控，滋养细胞浸润不良是导致子痫前期重要原因，我们的研究发现人类Lin28B在胎盘组织中表达呈时序性，与滋养细胞浸润状态有关，妊娠早期表达明显高于妊娠中晚期， 在子痫前期明显下调，提示Lin28B对滋养细胞浸润起时序化调控作用；通过体外培养滋养细胞株，转染Lin28B，滋养细胞浸润抑制基因KiSS-1表达降低，反之，进行Lin28B的敲减，滋养细胞浸润抑制基因KiSS-1表达增高。研究发现KiSS-1mRNA含Lin28B调控序列，Lin28B可通过调控下游基因KiSS-1mRNA起转录后调控作用，并构建Lin28B慢病毒载体转入前期构建成功的子痫前期动物模型，验证Lin28B对滋养细胞浸润不良的逆转作用，阐明子痫前期发病机制及提供新的防治靶点。