LAMA2调控滋养细胞功能参与胎儿生长受限的作用机制研究

LAMA2 protein, which is found to be differentially down-regulated in fetal growth restriction (FGR) placental tissue by mass spectrometry, is significantly positively correlated with fetal birth weight. Our studies have found that the overexpression of LAMA2 can promote trophoblastic proliferation and inhibit trophoblastic apoptosis. Both bioinformatics analysis and experiments show that LAMA2 may interact with ITGA7 of the PI3K/AKT signaling pathway. The PI3K/AKT pathway has been confirmed to be closely related to cell function and fetal growth. Therefore, it is suggested that LAMA2 would cause trophoblastic dysfunction by interacting with ITGA7 and inhibit PI3K/AKT signaling pathway in FGR. This study would further clarify the association of LAMA2 expression level in placenta tissue and birth weight by expanding the clinical sample. Using the strategies of overexpressing and silencing LAMA2, we intend to explicit the effect of LAMA2 on the function of trophoblast cells and PI3K/AKT signaling pathway with HTR-8/SVneo trophoblast cell as the research object. Moreover, we will use the rescue experiment to systematically clarify the mechanism of LAMA2 relating with ITGA7 of PI3K/AKT signaling pathway in FGR. The potential role of LAMA2 in the treatment of FGR will be evaluated by in vivo animal models by injecting LAMA2 overexpression of lentivirus. This study will provide a new theoretical basis and intervention targets for the prevention and treatment of FGR.

LAMA2是我们借助质谱技术发现的、差异低表达于胎儿生长受限（FGR）胎盘、与胎儿出生体重显著正相关的蛋白。前期发现过表达LAMA2可促进滋养细胞增殖并抑制其凋亡，且可能与PI3K/AKT信号通路激活有关。进一步生信分析及预实验显示，LAMA2可与PI3K/AKT信号通路中的ITGA7相互作用。本研究拟扩大临床样本，进一步明确胎盘中LAMA2表达水平与出生体重的相关性；探讨LAMA2及PI3K/AKT信号通路在不同胎盘功能紊乱影响因素刺激下的表达规律；采用过表达和沉默实验策略，论证LAMA2对滋养层细胞功能及PI3K/AKT信号通路的影响；采用挽救实验策略，系统论证LAMA2通过与ITGA7相互作用抑制PI3K/AKT信号通路引起滋养层细胞功能紊乱导致FGR发生的作用机制；并借助在体动物模型，评估LAMA2在FGR治疗中的潜在应用。本研究将为FGR的预防及治疗提供新理论依据及干预靶标。

胎儿生长受限（FGR）不仅是导致围产儿死亡和患病的重要原因，还与成年后多种慢性疾病有关。然而目前的研究尚不能完全阐明FGR的病因与发病机制，也未发现有效的防治方法。已证实，胎盘功能受损是FGR发生的最主要原因。胎盘局部微环境的变化、多种蛋白、细胞因子等的异常表达均可引起胎盘滋养层细胞增殖、迁移、凋亡等功能的紊乱，从而导致FGR的发生。本课题对前期工作中发现的通过质谱分析发现的差异蛋白LAMA2及ARF6进行研究。我们发现蛋白LAMA2及ARF6在胎儿生长受限胎盘中差异低表达，且ARF6稳定性优于LAMA2。我们采用过表达和沉默实验策略，通过构建ARF6过表达载体和合成ARF6干扰RNA成功实现了ARF6在滋养细胞中的过表达及表达沉默，并通过CCK-8及划痕实验等证实ARF6可显著影响滋养层细胞功能。通过对过表达ARF6的滋养细胞进行转录组测序，我们发现了ARF6过表达可能影响的下游基因以及相关信号通路。结果显示HSPA6可能是ARF6发挥作用的下游基因。此外，我们还尝试了通过代谢组学分析探索过表达ARF6滋养细胞的代谢物变化并整合转录组学进行了初步分析。这些结果为从胎盘层面认识FGR的发病机制提供了新线索，将为防治胎儿生长受限提供新思路及新靶点。