妊娠期糖尿病（GDM）严重影响母婴的健康。然而，GDM发生时期特殊、发病机制复杂、治疗手段有限。我们首次发现miR-140-3p与GDM密切相关，而山药多糖防治GDM效果显著，且调节miR-140-3p表达。现已明确，其靶基因SIRT1是调节胰岛素抵抗的关键节点。因此，推测山药多糖可能通过调节miR-140-3p/SIRT1信号轴以发挥疗效。为了验证该假说，本项目拟采用体内结合体外实验方法，应用GDM小鼠模型和胰岛素抵抗细胞模型，利用慢病毒基因转染，过表达或抑制miR-140-3p、SIRT1，或给予山药多糖处理，检测胰岛素抵抗、SIRT1-FOXO1/PGC-1α/NF-kB信号轴等相关指标变化，以阐明miR-140-3p调节GDM胰岛素抵抗的分子机制，同时明确山药多糖防治GDM的作用机制。这不仅有利于深入理解GDM的发生机制，还将为临床应用提供依据。

Gestational diabetes mellitus (GDM) has a serious impact on the health of mother and infant. However, with the special onset period and complex pathogenesis, its treatment is also limited as well. We firstly discovered that miR-140-3p is close related to GDM and Yam polysaccharide effect notable on the prevention and treatment GDM by regulating the expression of miR-140-3p. And it has been.confirmed that the target gene SIRT1 of miR-140-3p is a key joint in the regulation of insulin resistance. So our hypothesis is the prevention and treatment of Yam polysaccharide on GDM may be effected by the adjustment of miR-140-3p /SIRT1 signal shaft. In order to verify this hypothesis, we plan to apply the experiments of in vivo and vitro with a GDM mice model and an insulin resistance cell model respectively in this study, and detect the changes of insulin resistance and other relevant indications of SIRT1-FOXO1/PGC-1α/NF-kB signal shaft by the overexpression/over suppression miR-140-3p and SIRT1 individually or commonly before and after the intervention of Yam polysaccharide.in these models, and finally to illuminate the molecular mechanism of miR-140-3p on regulation of insulin resistance in GDM and the effective mechanism of and Yam polysaccharide in it. Those work are not only beneficial to deeply understand the.pathogenesis of GDM, but also lay foundation of the safety, effective and convenient drug development in the future.