Endothelial Piezo1 stimulates angiogenesis to offer protection against intestinal ischemia-reperfusion injury in mice.

BACKGROUND: Intestinal ischemia-reperfusion (I/R) injury, which occurs in the ileum and not only leads to intestinal tissue damage, but also may trigger systemic inflammatory responses, is a prevalent pathological condition that is typically associated with acute intestinal ischemia, surgical procedures, or trauma. However, the precise underlying pathogenic mechanisms have not yet been fully uncovered. In this study, we explored the specific roles and underlying mechanisms by which endothelial Piezo1 is involved in intestinal I/R injury. METHODS: We evaluated the roles of Piezo1 using both in vivo mouse intestinal ischemia-reperfusion (I/R) injury and in vitro hypoxia-reoxygenation (H/R) models. The expression of Piezo1 was assessed using immunofluorescence and RT-qPCR. In vivo and in vitro experiments involving endothelial knockout and activation of Piezo1 with the specific agonist Yoda1 were conducted to observe the effects on angiogenesis and injury. RESULTS: We found that in post-intestinal I/R mice, Piezo1 expression was markedly increased and was mainly abundant in ileum endothelial cells. Specific knockout of endothelial Piezo1 exhibited a more severe phenotype characterized by accelerating damage to the ileum structure, increasing inflammatory response, and inhibiting angiogenesis. Yoda1-mediated activation of Piezo1 significantly ameliorated intestinal I/R injury. Activation of Piezo1 induced by Yoda1 or H/R promoted angiogenesis in Human Umbilical Vein Endothelial Cells (HUVECs), which was inhibited by GsMTx4. Piezo1 mediated endothelial angiogenesis was linked to an increase of extracellular Ca(2+) influx, which in turn enhanced hypoxia-inducible factor 1 alpha (HIF-1α) signaling pathway. CONCLUSIONS: Our findings indicate that Piezo1 plays a crucial role in protecting against intestinal I/R injury by promoting angiogenesis in endothelial cells, possibly through the activation of the Ca(2+)/HIF-1α/VEGF signaling pathway. This suggests that targeting endothelial Piezo1 channels could be a therapeutic strategy for ileum I/R injury.