Joshi Sagar D, Jackson Timothy R, Zhang Lin, Stuckenholz Carsten, Davidson Lance A
Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
J Cell Sci. 2025 Sep 15;138(18). doi: 10.1242/jcs.263877. Epub 2025 Oct 2.
Extracellular signals regulate epithelial homeostasis, cell fate and the patterning of cell behaviors during embryogenesis, wound healing, regeneration and disease progression. Previous studies in our group found that cell lysate from intentionally wounded Xenopus laevis embryos triggers a strong but transient contraction in neighboring epithelia, whether contiguous to the wound site or in non-wounded embryos. We previously identified extracellular ATP (eATP) as a possible candidate signal. Here we test additional candidates and find that several nucleotides, including ADP, UTP and UDP, also trigger contractility. Through a temporal and spatial screen of lysate activity, an inhibitor screen and morpholino knockdown of candidate receptors, we find that contractility is mediated by a G-protein-coupled purinergic receptor, P2Y2 (P2RY2). Activated P2RY2 triggers F-actin assembly and myosin II contractility. Knockdown of P2RY2 or overexpression of mutant G protein effectors abrogate epithelial contractility when epithelia are exposed to eATP or lysate. We demonstrate that the major contributors to epithelial contractility in lysate are the extracellular nucleotide triphosphates ATP and UTP, which are sensed by P2RY2 and transduced through G proteins to contract the epithelium.
细胞外信号调节上皮细胞稳态、细胞命运以及胚胎发育、伤口愈合、再生和疾病进展过程中细胞行为的模式。我们小组之前的研究发现，来自故意受伤的非洲爪蟾胚胎的细胞裂解物会在邻近上皮细胞中引发强烈但短暂的收缩，无论这些上皮细胞是与伤口部位相邻还是在未受伤的胚胎中。我们之前将细胞外ATP（eATP）确定为一种可能的候选信号。在此，我们测试了其他候选物，发现包括ADP、UTP和UDP在内的几种核苷酸也能引发收缩。通过对裂解物活性进行时空筛选、抑制剂筛选以及对候选受体进行吗啉代敲低，我们发现收缩是由一种G蛋白偶联嘌呤能受体P2Y2（P2RY2）介导的。激活的P2RY2触发F-肌动蛋白组装和肌球蛋白II收缩。当上皮细胞暴露于eATP或裂解物时，P2RY2的敲低或突变G蛋白效应器的过表达会消除上皮收缩。我们证明，裂解物中上皮收缩的主要贡献者是细胞外三磷酸核苷酸ATP和UTP，它们被P2RY2感知并通过G蛋白转导以收缩上皮细胞。
