Abstract:
DNA methylation in neurons is directly linked to neuronal genome regulation and maturation. Unlike other tissues, vertebrate neurons accumulate high levels of atypical DNA methylation in the CH sequence context (mCH) during early postnatal brain development. Here, we investigate to what extent neurons derived in vitro from both mouse and human pluripotent stem cells recapitulate in vivo DNA methylation patterns. While human ESC-derived neurons did not accumulate mCH in either 2D culture or 3D organoid models even after prolonged culture, cortical neurons derived from mouse ESCs acquired in vivo levels of mCH over a similar time period in both primary neuron cultures and in vivo development. mESC-derived neuron mCH deposition was coincident with a transient increase in Dnmt3a, preceded by the postmitotic marker Rbfox3 (NeuN), was enriched at the nuclear lamina, and negatively correlated with gene expression. We further found that methylation patterning subtly differed between in vitro mES-derived and in vivo neurons, suggesting the involvement of additional noncell autonomous processes. Our findings show that mouse ESC-derived neurons, in contrast to those of humans, can recapitulate the unique DNA methylation landscape of adult neurons in vitro over experimentally tractable timeframes, which allows their use as a model system to study epigenome maturation over development.
摘要:
神经元中的DNA甲基化与神经元基因组调控和成熟直接相关。与其他组织不同,脊椎动物神经元在出生后早期大脑发育过程中在CH序列背景(mCH)中积累了高水平的非典型DNA甲基化。这里,我们研究了从小鼠和人类多能干细胞体外衍生的神经元在体内DNA甲基化模式中的概括程度。尽管人ESC衍生的神经元即使在长时间培养后也不会在2D培养或3D类器官模型中积累mCH,源自小鼠ESC的皮质神经元在初级神经元培养和体内发育中在相似的时间段内获得了体内mCH水平。mESC衍生的神经元mCH沉积与Dnmt3a的瞬时增加一致,之前是有丝分裂后标记Rbfox3(NeuN),在核层富集,与基因表达呈负相关。我们进一步发现,甲基化模式在体外mES衍生的神经元和体内神经元之间存在微妙的差异,表明参与了其他非细胞自主过程。我们的发现表明,小鼠ESC来源的神经元,与人类相比,可以在实验上处理的时间范围内概括体外成年神经元的独特DNA甲基化景观,这使得它们可以用作模型系统来研究表观基因组在发育过程中的成熟。