Background & Aims

The enteric nervous system (ENS) regulates gastrointestinal function via different subtypes of neurons, organized into fine-tuned neural circuits. It is not clear how cell diversity is created within the embryonic ENS; information required for development of cell-based therapies and models of enteric neuropathies. We aimed to identify proteins that regulate ENS differentiation and network formation.

Methods

We generated and compared RNA expression profiles of the entire ENS, ENS progenitor cells, and non-ENS gut cells of mice, collected at embryonic days 11.5 and 15.5, when different subtypes of neurons are formed. Gastrointestinal tissues from R26ReYFP reporter mice crossed to Sox10-CreER^T2 or Wnt1-Cre mice were dissected and the 6 populations of cells were isolated by flow cytometry. We used histochemistry to map differentially expressed proteins in mouse and human gut tissues at different stages of development, in different regions. We examined enteric neuronal diversity and gastric function in Wnt1-Cre x Sox6^fl/fl mice, which do not express the Sox6 gene in the ENS.

Results

We identified 147 transcription and signaling factors that varied in spatial and temporal expression during development of the mouse ENS. Of the factors also analyzed in human ENS, most were conserved. We uncovered 16 signaling pathways (such as fibroblast growth factor and Eph/ephrin pathways). Transcription factors were grouped according to their specific expression in enteric progenitor cells (such as MEF2C), enteric neurons (such as SOX4), or neuron subpopulations (such as SATB1 and SOX6). Lack of SOX6 in the ENS reduced the numbers of gastric dopamine neurons and delayed gastric emptying.

Conclusions

Using transcriptome and histochemical analyses of the developing mouse and human ENS, we mapped expression patterns of transcription and signaling factors. Further studies of these candidate determinants might elucidate the mechanisms by which enteric stem cells differentiate into neuronal subtypes and form distinct connectivity patterns during ENS development. We found expression of SOX6 to be required for development of gastric dopamine neurons.

中文翻译：

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转录和信号调节剂在发展小鼠和人类肠道神经系统的神经元亚型。

背景与目标

肠神经系统（ENS）通过神经元的不同亚型来调节胃肠道功能，这些亚型被组织成微调的神经回路。尚不清楚胚胎ENS中如何产生细胞多样性。开发基于细胞的疗法和肠道神经病模型所需的信息。我们旨在鉴定调节ENS分化和网络形成的蛋白质。

方法

我们生成并比较了小鼠的整个ENS，ENS祖细胞和非ENS肠道细胞的RNA表达谱，当形成不同亚型的神经元时，它们在胚胎的第11.5天和15.5天收集。解剖与Sox10-CreER ^T2或Wnt1-Cre小鼠杂交的R26ReYFP报告基因小鼠的胃肠道组织，并通过流式细胞仪分离6个细胞群体。我们使用组织化学法在小鼠和人类肠道组织中处于不同发育阶段，不同区域的差异表达蛋白作图。我们检查了Wnt1-Cre x Sox6 ^{fl / fl}小鼠的肠道神经元多样性和胃功能，这些小鼠在ENS中未表达Sox6基因。

结果

我们确定了147种转录和信号转导因子，它们在小鼠ENS的发育过程中在空间和时间表达上都有差异。在人类ENS中也分析的因素中，大多数是保守的。我们发现了16条信号通路（例如成纤维细胞生长因子和Eph / ephrin通路）。根据转录因子在肠祖细胞（如MEF2C），肠神经元（如SOX4）或神经元亚群（如SATB1和SOX6）中的特异性表达进行分组。ENS中SOX6的缺乏减少了胃多巴胺神经元的数量并延迟了胃排空。

结论

使用转录组和正在发展的小鼠和人类ENS的组织化学分析，我们绘制了转录和信号转导因子的表达模式。这些候选决定因素的进一步研究可能阐明了肠干细胞在ENS发育过程中分化为神经元亚型并形成不同的连通性模式的机制。我们发现SOX6的表达是胃多巴胺神经元发育所必需的。