Bai Chunyu, Gao Yuhua, Zhang Xiangyang, Yang Wancai, Guan Weijun
Key Laboratory of Precision Oncology of Shandong Higher Education, Institute of Precision Medicine, Jining Medical University, Jining, 272067, PR China.
Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
Oncotarget. 2017 Oct 16;8(63):106844-106857. doi: 10.18632/oncotarget.21883. eCollection 2017 Dec 5.
miRNAs regulate insulin secretion, pancreatic development, and beta-cell differentiation. However, their function in the differentiation of IPCs from MSCs is poorly understood. In this study, to screen for miRNAs and their targets that function during the formation of IPCs from MSCs, we examined the miRNA expression profiles of MSCs and IPCs using RNA-seq and qPCR to confirm the above results. We found that miR-34c exhibited transient upregulation at an early stage of the formation of IPCs derived from MSCs. Next, we analyzed the biological function of miR-34c by predicting its targets using bioinformatic tools. Combining our data with those from previous reports, we found that miR-34c and its targets play an important role in the formation of IPCs. Therefore, we overexpressed miR-34c and expressed small interfering RNAs of its targets in MSCs to investigate their functions in IPC formation. We found that miR-34c acts as a bidirectional switch in the formation of IPCs derived from MSCs by regulating the expression of targets to affect insulin synthesis and secretion. miR-34c was shown to downregulate its targets, including PDE7B, PDGFRA, and MAP2K1, to increase proinsulin synthesis, but when miR-34c continually dysregulated such expression, it suppressed the expression of other targets, namely ACSL4 and SAR1A, weakening insulin secretion in IPCs. These results suggest that endogenous miRNAs involved in the formation of IPCs from stem cells should be considered in the development of effective cell transplant therapy for diabetes.
微小RNA（miRNAs）调节胰岛素分泌、胰腺发育和β细胞分化。然而，它们在间充质干细胞（MSCs）向胰岛祖细胞（IPCs）分化过程中的功能尚不清楚。在本研究中，为了筛选在MSCs形成IPCs过程中发挥作用的miRNAs及其靶标，我们使用RNA测序（RNA-seq）和定量聚合酶链反应（qPCR）检测了MSCs和IPCs的miRNA表达谱，以证实上述结果。我们发现，miR-34c在源自MSCs的IPCs形成早期表现出短暂上调。接下来，我们通过生物信息学工具预测miR-34c的靶标，分析其生物学功能。将我们的数据与先前报道的数据相结合，我们发现miR-34c及其靶标在IPCs形成中起重要作用。因此，我们在MSCs中过表达miR-34c并表达其靶标的小干扰RNA，以研究它们在IPCs形成中的功能。我们发现，miR-34c通过调节靶标的表达来影响胰岛素合成和分泌，从而在源自MSCs的IPCs形成中充当双向开关。结果显示，miR-34c下调其靶标，包括磷酸二酯酶7B（PDE7B）、血小板衍生生长因子受体A（PDGFRA）和丝裂原活化蛋白激酶激酶1（MAP2K1），以增加胰岛素原合成，但当miR-34c持续失调这种表达时，它会抑制其他靶标，即长链脂酰辅酶A合成酶4（ACSL4）和Sarl1蛋白家族成员A（SAR1A）的表达，削弱IPCs中的胰岛素分泌。这些结果表明，在开发有效的糖尿病细胞移植治疗方法时，应考虑参与干细胞形成IPCs的内源性miRNAs。
