Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, China.
J Transl Med. 2022 Apr 21;20(1):180. doi: 10.1186/s12967-022-03386-8.
Insulin resistance (IR) during gestational diabetes mellitus (GDM) has been linked to dysregulated insulin-PI3K/Akt pathway. A defective insulin-PI3K/Akt pathway and dysregulated circular RNA (circRNA) levels have been observed in the placentas of patients with GDM; however, the mechanisms underlying this association remain unclear.
circRNAs potentially associated with GDM were selected through bioinformatics analysis and initially identified by quantitative real-time PCR (qPCR) in 9 GDM patients and 9 healthy controls, of which circMAP3K4 was further validated in additional 84 samples by qPCR. circMAP3K4 identity and localization were verified. Pearson correlation analysis was applied to evaluate the correlation between circMAP3K4 expression in the placental tissues of GDM patients and IR-related indicators. An IR model of trophoblasts was constructed using glucosamine. Interactions between miR-6795-5p and circMAP3K4 or PTPN1 were confirmed using a dual-luciferase reporter assay. The circMAP3K4/miR-6795-5p/PTPN1 axis and key markers in the insulin-PI3K/Akt pathway in placentas and trophoblasts were evaluated through qRT-PCR, immunofluorescence, and western blotting. The role of circMAP3K4 in glucose metabolism and cell growth in trophoblasts was determined using the glucose uptake and CCK8 assay, respectively.
circMAP3K4 was highly expressed in the placentas of patients with GDM and the IR trophoblast model; this was associated with a dysregulated insulin-PI3K/Akt pathway. circMAP3K4 in the placentas of GDM patients was positively correlated with weight gain during pregnancy and time-glucose area under the curve of OGTT. circMAP3K4 and PTPN1 could both bind to miR-6795-5p. miR-6795-5p and PTPN1 were downregulated and upregulated, respectively, in the placentas of GDM patients and the IR trophoblast model. circMAP3K4 silencing or miR-6795-5p overexpression partially reversed the decrease in glucose uptake, inhibition in cell growth, and downregulated IRS1 and Akt phosphorylation in IR-trophoblasts; this restoration was reversed upon co-transfection with an miR-6795-5p inhibitor or PTPN1.
circMAP3K4 could suppress the insulin-PI3K/Akt signaling pathway via miR-6795-5p/PTPN1 axis, probably contributing to GDM-related IR.
妊娠期糖尿病（GDM）期间的胰岛素抵抗（IR）与失调的胰岛素-PI3K/Akt 通路有关。在 GDM 患者的胎盘组织中观察到缺陷的胰岛素-PI3K/Akt 通路和失调的环状 RNA（circRNA）水平；然而，这种关联的机制尚不清楚。
通过生物信息学分析选择与 GDM 相关的 circRNAs，并通过定量实时 PCR（qPCR）在 9 名 GDM 患者和 9 名健康对照者中初步鉴定，其中 circMAP3K4 进一步通过 qPCR 在另外 84 个样本中验证。验证 circMAP3K4 的身份和定位。应用 Pearson 相关分析评估 GDM 患者胎盘组织中 circMAP3K4 表达与 IR 相关指标之间的相关性。使用氨基葡萄糖构建滋养细胞的 IR 模型。通过双荧光素酶报告基因检测证实 miR-6795-5p 与 circMAP3K4 或 PTPN1 之间的相互作用。通过 qRT-PCR、免疫荧光和 Western blot 评估胎盘和滋养细胞中 circMAP3K4/miR-6795-5p/PTPN1 轴和胰岛素-PI3K/Akt 通路中的关键标记物。通过葡萄糖摄取和 CCK8 测定分别确定 circMAP3K4 在滋养细胞葡萄糖代谢和细胞生长中的作用。
circMAP3K4 在 GDM 患者的胎盘和 IR 滋养细胞模型中高表达；这与失调的胰岛素-PI3K/Akt 通路有关。GDM 患者胎盘组织中的 circMAP3K4 与妊娠期间体重增加和 OGTT 时间-葡萄糖曲线下面积呈正相关。circMAP3K4 和 PTPN1 均可与 miR-6795-5p 结合。miR-6795-5p 和 PTPN1 在 GDM 患者和 IR 滋养细胞模型中的胎盘组织中分别下调和上调。IR 滋养细胞中 circMAP3K4 沉默或 miR-6795-5p 过表达部分逆转了葡萄糖摄取减少、细胞生长抑制以及 IRS1 和 Akt 磷酸化下调；当共转染 miR-6795-5p 抑制剂或 PTPN1 时，这种恢复被逆转。
circMAP3K4 可能通过 miR-6795-5p/PTPN1 轴抑制胰岛素-PI3K/Akt 信号通路，可能导致与 GDM 相关的 IR。
