The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing 100730, P.R. China.
Mol Med Rep. 2018 Mar;17(3):3967-3971. doi: 10.3892/mmr.2017.8312. Epub 2017 Dec 19.
As a member of miR-17-92 miRNA clusters, miR‑19a has been considered to regulate hepatic glycogenesis by mediating the PI3K/AKT signaling pathway. However, whether miR‑19a serves an important role in gluconeogenesis in hepatocytes remains unknown. In the present study, the impact of miR‑19a on gluconeogenesis in HEP1‑6 cells and its mechanisms of action were investigated. It was observed that overexpression of miR‑19a led to decreased glucose production, accompanied by increased activation of the AKT/FOXO1 signaling pathway and downregulated expression of gluconeogenesis‑associated genes, including peroxisome proliferator‑activated receptor γ coactivator 1α, phosphoenolpyruvate carboxykinase and glucose 6‑phosphatase in the HEP1‑6 cells transfected with the miR‑19a mimic. In contrast, suppression of miR‑19a impaired the activation of the AKT/FOXO1 signaling pathway and increased the expression of gluconeogenesis‑associated genes, accompanied by an elevated glucose production. Additionally, phosphatase and tensin homolog (PTEN) was identified as a target of miR‑19a and participated in the miR‑19a‑mediated gluconeogenesis in hepatocytes. These findings provide mechanistic insight into the effects of miR‑19a on the regulation of the AKT/FOXO1 signaling pathway and the expression of gluconeogenesis‑associated genes. MiR‑19a may mediate gluconeogenesis in hepatocytes by downregulating PTEN expression.
作为 miR-17-92 微 RNA 簇的成员之一,miR-19a 被认为通过介导 PI3K/AKT 信号通路来调节肝糖生成。然而,miR-19a 是否在肝细胞的糖异生中起重要作用尚不清楚。在本研究中,研究了 miR-19a 对 HEP1-6 细胞糖异生的影响及其作用机制。结果观察到,过表达 miR-19a 导致葡萄糖生成减少,同时 AKT/FOXO1 信号通路的激活增加,糖异生相关基因的表达下调,包括过氧化物酶体增殖物激活受体 γ 共激活因子 1α、磷酸烯醇丙酮酸羧激酶和葡萄糖 6-磷酸酶在转染 miR-19a 模拟物的 HEP1-6 细胞中。相反,抑制 miR-19a 会损害 AKT/FOXO1 信号通路的激活,并增加糖异生相关基因的表达,同时葡萄糖生成增加。此外,发现磷酸酶和张力蛋白同源物 (PTEN) 是 miR-19a 的靶基因,并参与了肝细胞中 miR-19a 介导的糖异生。这些发现为 miR-19a 对 AKT/FOXO1 信号通路和糖异生相关基因表达的调节作用提供了机制上的见解。miR-19a 可能通过下调 PTEN 表达来介导肝细胞的糖异生。