Abstract: Objective To study the effects of gestational diabetes (GDM) on morphological structure of brain tissue and microribonucleotide (miRNA) expression profile in neonatal mice, and to provide a new research target for the prevention and treatment of abnormal neurodevelopment in GDM progeny. Methods The pregnant mice were divided into model group and control group, each group consisted of 10 mice. The model group mice established a GDM model by injecting streptozotocin to measure fasting blood glucose (FPG) and random blood glucose (GLU) at different times. Successful molded mice were randomly divided into model group A and model group C, and control mice were divided into control group B and control group D, with 5 mice in each group.The newborn mice in groups A and B were used for hippocampal tissue GeneChip detection and brain morphology structure observation, and group C and D newborn mice were used for qRT-PCR detection of hippocampus tissue expression differences to verify the differentially expressed genes of miRANs obtained by GeneChip screening.After giving birth, the neonatal mice were sacrificed by decapitation, and the brain tissue was dissected to observe the overall morphological structure. The structural changes of hippocampus were observed under HE chromogenic microscope. The Agilent mouse miRNA oligonucleotide gene chip was used to detect the miRNA expression profile of mouse hippocampus, screen differential miRNAs and predict their target genes, and conduct GO analysis and signal transduction pathway analysis of target genes. The relative expression levels of the screened miRNAs were verified by qRT-PCR. Results Compared with the control group, the GLU increased significantly from the 3rd day after drug administration in the model group (P<0.01). Macroscopic observation of control group B mice had normal brain morphology and structure, smooth appearance, clear gyrus, close arrangement of hippocampus cell structure, uniform staining and complete structure; in model group A, the number of hippocampus cells decreased, loose arrangement and deep staining. In the initial screen of miRNA microarray, there were 11 differentially expressed miRNAs between control and model groups, all of which were downregulated miRNAs, including let-7b-5p、miR-130b-3p、miR-181c-5p、miR-181d-5p、miR-3099-3p、miR-3470a、miR-3473a、miR-3473b、miR-500-3p、miR-532-5p、miR-7047-5p(P＜0.05)。Two miRNAs (miR-3473b, miR-7047-75p) and 5 target genes (MAPK3, MAPK11, MAPK14, CALM3, AKT3). The relative expression of miR-3473b and miR-7047-5p in model group C were lower than that in control group D (t=19.13 and 6.24, P<0.05), and the validation results were consistent with the microarray test results. Conclusion Compared with the offspring of normal pregnant mice, GDM offspring mice have abnormal development of brain structure and damage of hippocampal nerve cells, and there are a large number of abnormal expression of miRNAs in hippocampal tissue. Differentially expressed miRNAs can be used as research targets for prevention and treatment of GDM offspring neurodevelopmental abnormalities.

Key words: gestational diabetes, microRNA, morphological structure of brain tissue, gene expression profile

摘要： 目的 研究妊娠期糖尿病(GDM)对新生小鼠脑组织形态结构及微小核糖核苷酸(miRNAs)表达谱的影响,为GDM子代神经发育异常预防和治疗提供新的研究靶点。方法 将妊娠鼠分为模型组和对照组各10只,模型组小鼠通过注射链脲佐菌素建立GDM模型,测量不同时间的空腹血糖(FPG)和随机血糖(GLU)。造模成功小鼠随机分为模型A组和模型C组,对照组小鼠分为对照B组和对照D组,每组各5只。其中A、B组新生小鼠用于进行海马组织基因芯片检测及大脑形态结构观察;C、D组新生小鼠用于qRT-PCR检测海马组织的表达差异,以验证基因芯片筛选所得miRANs差异表达基因。新生小鼠脱颈处死,剥离脑组织观察整体形态结构,HE显色显微镜下观察海马组织结构变化。基因芯片检测小鼠海马组织miRNA表达谱,筛选差异miRNAs并预测其靶基因,对靶基因进行GO分析及信号转导通路分析。以qRT-PCR验证筛选的miRNAs相对表达量。结果 与对照组比较,模型组自给药后第3天起GLU显著上升(P＜0.01)。肉眼观察对照B组小鼠脑形态结构正常,外形结构光滑,脑回清晰,海马组织细胞结构排列紧密,染色均匀,结构完整;模型A组脑沟变浅,脑回增宽,海马组织细胞数量减少,排列疏松,核固缩深染。miRNA芯片初筛,对照组和模型组海马组织有11个差异表达miRNAs,全部为下调miRNAs,包括let-7b-5p、miR-130b-3p、miR-181c-5p、miR-181d-5p、miR-3099-3p、miR-3470a、miR-3473a、miR-3473b、miR-500-3p、miR-532-5p、miR-7047-5p(P＜0.05)。靶基因预测和GO分析筛选出2个miRNAs(miR-3473b、miR-7047-5p),和5个与神经营养素信号通路相关的靶基因(MAPK3、MAPK11、MAPK14、CALM3、AKT3)。模型C组的miR-3473b及miR-7047-5p相对表达量均低于对照D组(t=19.13、6.24,P＜0.05),验证结果与芯片检测结果相符。结论 与正常妊娠小鼠子代相比,GDM子代小鼠存在脑结构发育异常和海马神经细胞损伤,且海马组织存在miRNAs异常表达,差异表达miRNA可作为GDM子代神经发育异常预防和治疗的研究靶点。

关键词: 妊娠期糖尿病, 微小核糖核苷酸, 脑组织形态结构, 基因表达谱