Kim Ho-Tae, Jeong Sin-Gu, Cho Goang-Won
Department of Biology, College of Natural Science, Chosun University, Gwangju 501-759, Republic of Korea; Department of Life Science, BK21-Plus Research Team for Bioactive Control Technology, Chosun University, Gwangju 501-759, Republic of Korea.
Department of Biology, College of Natural Science, Chosun University, Gwangju 501-759, Republic of Korea; Department of Life Science, BK21-Plus Research Team for Bioactive Control Technology, Chosun University, Gwangju 501-759, Republic of Korea.
Neurochem Int. 2016 Jun;96:77-83. doi: 10.1016/j.neuint.2016.03.002. Epub 2016 Mar 4.
Recent studies have shown that epigenomic modifications are significantly associated with neuronal differentiation. Many neuronal specific genes contain the repressor element-1 (RE-1), which recruits epigenetic modulators, such as the histone methyltransferase G9a and interrupts the expression of neuronal genes in non-neuronal cells. This study investigated the functional role of G9a during neuronal differentiation of human bone marrow mesenchymal stem cells (BM-MSCs). Human BM-MSCs treated with the G9a inhibitor BIX01294 showed an increased expression of various neuronal-lineage genes. Using genomic sequence analysis, we identified RE-1 consensus sequences in the proximal region of several neuronal-specific genes. Chromatin immunoprecipitation (ChIP) assay results have showed that H3K9me2 (dimethylation of lysine 9 on histone 3) occupancy at RE-1-containing sequences from neuronal-specific genes was significantly decreased in BIX01294-MSCs. When BIX01294-MSCs were differentiated with neuronal induction medium, cells differentiated more effectively into neuron-like cells, complete with a cell body and dendrites. Expression of neuronal-specific genes containing the RE-1 sequences was significantly increased in differentiated BIX01294-MSCs, as confirmed by immunocytochemical staining and immunoblotting. Thus, this study shows that BIX01294 pretreated human BM-MSCs can be effectively differentiated into neuron-like cells by induced expression of neuronal-specific genes containing RE-1 sequences.
最近的研究表明，表观基因组修饰与神经元分化显著相关。许多神经元特异性基因含有阻遏元件1（RE-1），它招募表观遗传调节剂，如组蛋白甲基转移酶G9a，并阻断非神经元细胞中神经元基因的表达。本研究调查了G9a在人骨髓间充质干细胞（BM-MSC）神经元分化过程中的功能作用。用G9a抑制剂BIX01294处理的人BM-MSC显示出各种神经谱系基因的表达增加。通过基因组序列分析，我们在几个神经元特异性基因的近端区域鉴定出RE-1共有序列。染色质免疫沉淀（ChIP）分析结果表明，在BIX01294处理的MSC中，神经元特异性基因含RE-1序列处的H3K9me2（组蛋白3赖氨酸9二甲基化）占有率显著降低。当用神经元诱导培养基诱导BIX01294处理的MSC分化时，细胞能更有效地分化为具有细胞体和树突的神经元样细胞。免疫细胞化学染色和免疫印迹证实，在分化的BIX01294处理的MSC中，含RE-1序列的神经元特异性基因的表达显著增加。因此，本研究表明，经BIX0129预处理的人BM-MSC通过诱导含RE-1序列的神经元特异性基因的表达可有效分化为神经元样细胞。
