Laboratoire Matière et Systèmes Complexes, Université Paris Cité, CNRS UMR 7057, 10 rue Alice Domon et Léonie Duquet, 75013, Paris, France.
ANIMALLIANCE, Insourcing Department, Paris, France.
Commun Biol. 2024 Oct 7;7(1):1277. doi: 10.1038/s42003-024-06976-y.
Intestinal smooth muscle differentiation is a complex physico-biological process involving several different pathways. Here, we investigate the properties of Ca waves in the developing intestinal mesenchyme using GCamp6f expressing mouse embryos and investigate their relationship with smooth muscle differentiation. We find that Ca waves are absent in the pre-differentiation mesenchyme and start propagating immediately following α-SMA expression. Ca waves are abrogated by Ca1.2 and gap-junction blockers, but are independent of the Rho pathway. The myosine light-chain kinase inhibitor ML-7 strongly disorganized or abolished Ca waves, showing that perturbation of the contractile machinery at the myosine level also affected the upstream Ca handling chain. Inhibiting Ca waves and contractility with Ca1.2 blockers did not perturb circular smooth muscle differentiation at early stages. At later stages, Ca1.2 blockers abolished intestinal elongation and differentiation of the longitudinal smooth muscle, leading instead to the emergence of KIT-expressing interstitial cells of Cajal at the gut periphery. Ca1.2 blockers also drove apoptosis of already differentiated, Ca1.2-expressing smooth muscle and enteric neural cells. We provide fundamental new data on Ca waves in the developing murine gut and their relation to myogenesis in this organ.
肠平滑肌分化是一个复杂的物理生物学过程，涉及几个不同的途径。在这里，我们使用表达 GCamp6f 的小鼠胚胎研究了发育中肠间充质中的钙波特性，并研究了它们与平滑肌分化的关系。我们发现，钙波在预分化间充质中不存在，并且在 α-SMA 表达后立即开始传播。钙波被 Ca1.2 和缝隙连接阻滞剂阻断，但与 Rho 途径无关。肌球蛋白轻链激酶抑制剂 ML-7 强烈扰乱或消除钙波，表明肌球蛋白水平的收缩机制扰动也影响了上游钙处理链。用 Ca1.2 阻断剂抑制钙波和收缩性不会干扰早期的环形平滑肌分化。在后期，Ca1.2 阻断剂消除了肠的伸长和纵向平滑肌的分化，导致在肠外周出现表达 KIT 的 Cajal 间质细胞。Ca1.2 阻断剂还驱动已经分化的、表达 Ca1.2 的平滑肌和肠神经细胞的凋亡。我们在发育中的小鼠肠道中提供了关于钙波的基本新数据，以及它们与该器官中肌发生的关系。
