Department of Obstetrics, Women's Hospital, of Zhejiang University School of Medicine, Hangzhou, China.
The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
Acta Diabetol. 2024 Jan;61(1):79-90. doi: 10.1007/s00592-023-02169-x. Epub 2023 Sep 9.
Gestational diabetes mellitus (GDM) affects a significant number of women worldwide and has been associated with lifelong health consequences for their offspring, including increased susceptibility to obesity, insulin resistance, and type II diabetes. Recent studies have suggested that aberrant expression of the long non-coding RNA Meg3 in the liver may contribute to impaired glucose metabolism in individuals. In this study, we aimed to investigate whether intrauterine exposure to hyperglycemia affects glucose intolerance in puberty by mediating the overexpression of LncMeg3 in the liver.
To test our hypothesis, we established an animal model of intrauterine hyperglycemia to mimic GDM. The progeny was observed for phenotypic changes, and intraperitoneal glucose tolerance tests, insulin tolerance tests, and pyruvate tolerance tests were conducted to assess glucose and insulin tolerance. We also measured LncMeg3 expression in the liver using real-time quantitative PCR and examined differential methylation areas (DMRs) in the Meg3 gene using pyrophosphoric sequencing. To investigate the role of LncMeg3 in glucose tolerance, we conducted Meg3 intervention by vein tail and analyzed the changes in the phenotype and transcriptome of the progeny using bioinformatics analysis.
We found that intrauterine exposure to hyperglycemia led to impaired glucose and insulin tolerance in the progeny, with a tendency toward increased fasting blood glucose in fat offspring at 16 weeks (P = 0.0004). LncMeg3 expression was significantly upregulated (P = 0.0061), DNMT3B expression downregulated (P = 0.0226), and DNMT3A (P = 0.0026), TET2 (P = 0.0180) expression upregulated in the liver. Pyrophosphoric sequencing showed hypomethylation in Meg3-DMRs (P = 0.0005). Meg3 intervention by vein tail led to a decrease in the percentage of obese and emaciated offspring (emaciation: 44% vs. 23%; obesity: 25% vs. 15%) and attenuated glucose intolerance. Bioinformatics analysis revealed significant differences in the transcriptome of the progeny, particularly in circadian rhythm and PPAR signaling pathways.
In conclusion, our study suggests that hypomethylation of Meg3-DMRs increases the expression of the imprinted gene Meg3 in the liver of males, which is associated with impaired glucose tolerance in GDM-F1. MEG3 interference may attenuate glucose intolerance, which may be related to transcriptional changes. Our findings provide new insights into the mechanisms underlying the long-term effects of intrauterine hyperglycemia on progeny health and highlight the potential of Meg3 as an intervention target for glucose intolerance.
妊娠糖尿病（GDM）影响全球大量女性，并且与后代终生健康后果相关，包括肥胖、胰岛素抵抗和 2 型糖尿病易感性增加。最近的研究表明，肝脏中长链非编码 RNA Meg3 的异常表达可能导致个体葡萄糖代谢受损。在本研究中，我们旨在通过研究宫内高血糖是否通过调节肝脏中 LncMeg3 的过表达来影响青春期葡萄糖不耐受，来探究这一问题。
为了验证我们的假设，我们建立了宫内高血糖动物模型来模拟 GDM。观察后代的表型变化，并进行腹腔内葡萄糖耐量试验、胰岛素耐量试验和丙酮酸耐量试验，以评估葡萄糖和胰岛素耐量。我们还使用实时定量 PCR 检测肝脏中 LncMeg3 的表达，并使用焦磷酸测序检测 Meg3 基因的差异甲基化区域（DMR）。为了研究 LncMeg3 在葡萄糖耐量中的作用，我们通过静脉尾巴进行 Meg3 干预，并使用生物信息学分析分析后代的表型和转录组变化。
我们发现，宫内高血糖暴露导致后代葡萄糖和胰岛素耐量受损，16 周时脂肪后代的空腹血糖有升高趋势（P = 0.0004）。LncMeg3 表达显著上调（P = 0.0061），DNMT3B 表达下调（P = 0.0226），DNMT3A（P = 0.0026），TET2（P = 0.0180）表达上调。焦磷酸测序显示 Meg3-DMRs 低甲基化（P = 0.0005）。静脉尾巴的 Meg3 干预导致肥胖和消瘦后代的比例降低（消瘦：44%比 23%；肥胖：25%比 15%），葡萄糖耐量减弱。生物信息学分析显示后代转录组存在显著差异，特别是在昼夜节律和 PPAR 信号通路。
总之，我们的研究表明，Meg3-DMRs 的低甲基化增加了男性肝脏中印记基因 Meg3 的表达，与 GDM-F1 中的葡萄糖耐量受损有关。MEG3 干扰可能减轻葡萄糖不耐受，这可能与转录变化有关。我们的发现为宫内高血糖对后代健康的长期影响的机制提供了新的见解，并强调了 Meg3 作为葡萄糖不耐受干预靶点的潜力。
