Jang Sujeong, Jeong Han-Seong
Department of Physiology, Chonnam National University Medical School, Gwangju 61469, Republic of Korea.
Neurosci Lett. 2018 Mar 6;668:24-30. doi: 10.1016/j.neulet.2018.01.006. Epub 2018 Jan 4.
Histone deacetylase (HDAC) inhibitors, which have an effect on cell homeostasis, cell cycle progression, and terminal differentiation, can act to promote self-renewal and enhance directed differentiation of several lineages of stem cells. However, the roles of HDAC inhibitors on neurogenic differentiation and the mechanisms of Wnt signaling following treatment with HDAC inhibitors remain unclear in stem cells. We hypothesized that HDAC inhibitors regulate downstream Wnt signaling and neurogenic differentiation of mesenchymal stem cells. Following neural induction with supplementary factors, human adipose tissue-derived mesenchymal stem cells (hADSCs) were differentiated into neurogenic cells in vitro. We examined the neurogenic differentiation induced by the HDAC inhibitors, MS-275, sodium butyrate (NaB), trichostatin A (TSA), and valproic acid (VPA), by RT-PCR and western blot analysis. Based on RT-PCR analysis, the expressions of NEUROG2 and NEFL were highly increased following HDAC inhibitor treatment compared with control medium. Most of the neuronal marker genes were expressed when neural-induced hADSCs (NI-hADSCs) were treated with the HDAC inhibitors individually. Interestingly, expression of most of the Wnt-related genes were highly increased following treatment with the HDAC inhibitors, especially with MS-275 treatment. Further, the protein level of Wnt5 was upregulated after neurogenic induction with MS-275 and VPA treatment, based on western blot analysis. Furthermore, we found that c-Jun expression was increased after treatment with the HDAC inhibitors, except with NaB. The protein levels of phosphor-JNK and phosphor-GSK-3β were upregulated considerably. In conclusion, the HDAC inhibitors could induce neurogenic differentiation of hADSCs by activating canonical Wnt or non-canonical Wnt signaling pathways.
组蛋白去乙酰化酶（HDAC）抑制剂可影响细胞稳态、细胞周期进程和终末分化，能够促进干细胞的自我更新并增强多个谱系干细胞的定向分化。然而，HDAC抑制剂在干细胞中对神经源性分化的作用以及HDAC抑制剂处理后Wnt信号通路的机制仍不清楚。我们推测HDAC抑制剂可调节间充质干细胞的下游Wnt信号通路和神经源性分化。在用补充因子进行神经诱导后，人脂肪组织来源的间充质干细胞（hADSCs）在体外分化为神经源性细胞。我们通过RT-PCR和蛋白质印迹分析检测了HDAC抑制剂MS-275、丁酸钠（NaB）、曲古抑菌素A（TSA）和丙戊酸（VPA）诱导的神经源性分化。基于RT-PCR分析，与对照培养基相比，HDAC抑制剂处理后NEUROG2和NEFL的表达显著增加。当神经诱导的hADSCs（NI-hADSCs）单独用HDAC抑制剂处理时，大多数神经元标记基因都有表达。有趣的是，在用HDAC抑制剂处理后，尤其是MS-275处理后，大多数Wnt相关基因的表达显著增加。此外，基于蛋白质印迹分析，在用MS-275和VPA处理进行神经源性诱导后，Wnt5的蛋白水平上调。此外，我们发现除NaB外，用HDAC抑制剂处理后c-Jun表达增加。磷酸化JNK和磷酸化GSK-3β的蛋白水平显著上调。总之，HDAC抑制剂可通过激活经典Wnt或非经典Wnt信号通路诱导hADSCs的神经源性分化。
