Department of Cytology, Institute of Anatomy, Ruhr University Bochum, 44780 Bochum, Germany.
Medical Proteom-Center, Ruhr University Bochum, 44780 Bochum, Germany.
Int J Mol Sci. 2020 May 28;21(11):3839. doi: 10.3390/ijms21113839.
The wide-ranging influence of vascular endothelial growth factor (VEGF) within the central (CNS) and peripheral nervous system (PNS), for example through effects on axonal growth or neuronal cell survival, is mainly mediated by VEGF receptor 2 (VEGFR-2). However, the regulation of VEGFR-2 expression during development is not yet well understood. As microRNAs are considered to be key players during neuronal maturation and regenerative processes, we identified the two microRNAs (miRNAs)-miR-129-5p and miR-130a-3p-that may have an impact on VEGFR-2 expression in young and mature sensory and lower motor neurons. The expression level of VEGFR-2 was analyzed by using in situ hybridization, RT-qPCR, Western blot, and immunohistochemistry in developing rats. microRNAs were validated within the spinal cord and dorsal root ganglia. To unveil the molecular impact of our candidate microRNAs, dissociated cell cultures of sensory and lower motor neurons were transfected with mimics and inhibitors. We depicted age-dependent VEGFR-2 expression in sensory and lower motor neurons. In detail, in lower motor neurons, VEGFR-2 expression was significantly reduced during maturation, in conjunction with an increased level of miR-129-5p. In sensory dorsal root ganglia, VEGFR-2 expression increased during maturation and was accompanied by an overexpression of miR-130a-3p. In a second step, the functional significance of these microRNAs with respect to VEGFR-2 expression was proven. Whereas miR-129-5p seems to decrease VEGFR-2 expression in a direct manner in the CNS, miR-130a-3p might indirectly control VEGFR-2 expression in the PNS. A detailed understanding of genetic VEGFR-2 expression control might promote new strategies for the treatment of severe neurological diseases like ischemia or peripheral nerve injury.
例如，血管内皮生长因子（VEGF）在中枢神经系统（CNS）和周围神经系统（PNS）中的广泛影响，主要通过对轴突生长或神经元细胞存活的影响来介导，主要由 VEGF 受体 2（VEGFR-2）介导。然而，发育过程中 VEGFR-2 表达的调节尚不清楚。由于 microRNAs 被认为是神经元成熟和再生过程中的关键参与者，我们鉴定了两种可能对年轻和成熟感觉和运动神经元中 VEGFR-2 表达有影响的 microRNAs（miRNAs）-miR-129-5p 和 miR-130a-3p。通过原位杂交、RT-qPCR、Western blot 和免疫组织化学分析，在发育中的大鼠中分析 VEGFR-2 的表达水平。在脊髓和背根神经节中验证了 microRNAs。为了揭示我们候选 microRNAs 的分子影响，我们用模拟物和抑制剂转染感觉和运动神经元的分离细胞培养物。我们描绘了感觉和运动神经元中年龄依赖性的 VEGFR-2 表达。具体而言，在运动神经元中，VEGFR-2 的表达在成熟过程中显著降低，同时 miR-129-5p 的水平增加。在感觉背根神经节中，VEGFR-2 的表达在成熟过程中增加，同时 miR-130a-3p 的表达增加。在第二步中，证明了这些 microRNAs 对 VEGFR-2 表达的功能意义。虽然 miR-129-5p 似乎以直接方式降低 CNS 中 VEGFR-2 的表达，但 miR-130a-3p 可能间接控制 PNS 中 VEGFR-2 的表达。对遗传 VEGFR-2 表达控制的详细了解可能会促进治疗缺血或周围神经损伤等严重神经疾病的新策略。
