Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China.
Department of Orthodontics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China.
Mol Med Rep. 2020 Aug;22(2):1008-1016. doi: 10.3892/mmr.2020.11177. Epub 2020 May 22.
Neural stem/progenitor cells (NSPCs) remain in the mammalian brain throughout life, where they have the ability to self‑renew and generate different types of cell in the central nervous system (CNS). Therefore, NSPCs may be a potential novel therapeutic strategy following damage to the CNS. Previous research has reported that microRNA (miR)‑29a served an important role in regulating cell proliferation, differentiation and survival; however, to the best of our knowledge, little is known of the effect of miR‑29a in neural differentiation. The present study aimed to investigate the effect of miR‑29a on the differentiation of NSPCs, determined via RNA interference, immunostaining, reverse transcription-quantitative PCR and western blotting. The present study discovered that the expression levels of miR‑29a were significantly upregulated in a time‑dependent manner during neural differentiation. Immunostaining showed that overexpression of miR‑29a promoted neural differentiation, which manifested in increased expression levels of neuron‑specific class III β‑tubulin (Tuj1); however, miR‑29a had no effect on neuroglial differentiation. The expression levels of Kruppel‑like factor 4 (KLF4) were downregulated following overexpression of miR‑29a, whereas the inhibition of miR‑29a demonstrated the opposite effect. These results suggested that the overexpression of miR‑29a may promote neural differentiation in cultured rat NSPCs by decreasing the expression levels of KLF4. Thus indicating that targeting KLF4, a crucial regulatory factor for the maintenance of stemness, may be a potential underlying mechanism of action for miR‑29a. In conclusion, the findings of the present study identified a potential mechanism of action for miR‑29a in NSPC differentiation and provided a novel insight into the treatment strategies for CNS damage.
神经干细胞/祖细胞(NSPCs)在哺乳动物的大脑中终生存在,具有自我更新和在中枢神经系统(CNS)中产生不同类型细胞的能力。因此,NSPCs 可能是 CNS 损伤后一种潜在的新型治疗策略。先前的研究报道,微小 RNA(miR)-29a 在调节细胞增殖、分化和存活方面发挥着重要作用;然而,据我们所知,miR-29a 在神经分化中的作用知之甚少。本研究旨在通过 RNA 干扰、免疫染色、逆转录-定量 PCR 和 Western blot 分析,研究 miR-29a 对 NSPC 分化的影响。本研究发现,miR-29a 的表达水平在神经分化过程中呈时间依赖性显著上调。免疫染色显示,miR-29a 的过表达促进了神经分化,表现为神经元特异性 III 型 β-微管蛋白(Tuj1)的表达水平增加;然而,miR-29a 对神经胶质分化没有影响。过表达 miR-29a 后,Kruppel 样因子 4(KLF4)的表达水平下调,而抑制 miR-29a 则表现出相反的效果。这些结果表明,miR-29a 的过表达可能通过降低 KLF4 的表达水平来促进培养的大鼠 NSPC 中的神经分化。这表明,靶向 KLF4,一种维持干细胞特性的关键调节因子,可能是 miR-29a 的潜在作用机制之一。总之,本研究确定了 miR-29a 在 NSPC 分化中的潜在作用机制,并为 CNS 损伤的治疗策略提供了新的见解。