Zhang Lu Yun, Chen Xiong Ying, Dong Hui, Xu Feng
Department of Pediatric Intensive Care Unit, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China.
Department of Gastroenterology, Xinqiao Hospital, Army Medical University, Chongqing, China.
Front Physiol. 2021 Mar 9;12:639857. doi: 10.3389/fphys.2021.639857. eCollection 2021.
: Since the role of store-operated calcium entry (SOCE) in endothelium-dependent hyperpolarization (EDH)-mediated vasorelaxation of mesenteric arteries in health and colitis is not fully understood, cyclopiazonic acid (CPA), a specific inhibitor of the sarco(endo) plasmic reticulum calcium-ATPases (SERCA), was used as a SOCE activator to investigate its role in normal mice and its alteration in colitis mice. : The changes in Ca signaling in vascular endothelial cells (VEC) were examined by single cell Ca imaging and tension of mesenteric arteries in response to CPA were examined using Danish DMT520A microvascular measuring system. : CPA activated the SOCE through depletion of the endoplasmic reticulum (ER) Ca in endothelial cells. CPA had a concentration-dependent vasorelaxing effect in endothelium-intact mesenteric arteries, which was lost after endothelial removal. Both nitric oxide (NO) and prostacyclin (PGI) inhibitors did not affect CPA-induced vasorelaxation; however, after both NO and PGI were inhibited, K channel blocker [10 mM tetraethylammonium chloride (TEA)] inhibited CPA-induced vasorelaxation while K channel activator (0.3 μM SKA-31) promoted it. Two SOCE blockers [30 μM SKF96365 and 100 μM flufenamic acid (FFA)], and an Orai channel blocker (30 μM GSK-7975A) inhibited this vasorelaxation. The inhibition of both Na/K-ATPase (NKA) and Na/Ca-exchange (NCX) also inhibited CPA-induced vasorelaxation. Finally, the CPA involved in EDH-induced vasorelaxation by the depletion of ER Ca of mesenteric arteries was impaired in colitis mice. : Depletion of ER Ca by CPA induces a vasorelaxation of mesenteric arteries that is mediated through EDH mechanism and invokes the activation of SOCE. The CPA-induced endothelium-dependent dilation is impaired in colitis which may limit blood perfusion to the intestinal mucosa.
由于在健康状态和结肠炎状态下，储存式钙内流（SOCE）在肠系膜动脉内皮依赖性超极化（EDH）介导的血管舒张中的作用尚未完全明确，因此使用肌浆网钙-ATP酶（SERCA）的特异性抑制剂环匹阿尼酸（CPA）作为SOCE激活剂，来研究其在正常小鼠中的作用以及在结肠炎小鼠中的变化。通过单细胞钙成像检测血管内皮细胞（VEC）中钙信号的变化，并使用丹麦DMT520A微血管测量系统检测肠系膜动脉对CPA的张力反应。CPA通过耗尽内皮细胞内质网（ER）钙来激活SOCE。CPA在内皮完整的肠系膜动脉中具有浓度依赖性的血管舒张作用，在内皮去除后这种作用消失。一氧化氮（NO）和前列环素（PGI）抑制剂均不影响CPA诱导的血管舒张；然而，在NO和PGI均被抑制后，钾通道阻滞剂[10 mM四乙铵氯化物（TEA）]抑制CPA诱导的血管舒张，而钾通道激活剂（0.3 μM SKA-31）则促进这种作用。两种SOCE阻滞剂[30 μM SKF96365和100 μM氟芬那酸（FFA）]以及一种Orai通道阻滞剂（30 μM GSK-7975A）均抑制这种血管舒张。钠钾ATP酶（NKA）和钠钙交换体（NCX）的抑制也抑制CPA诱导的血管舒张。最后，参与肠系膜动脉ER钙耗尽所致EDH诱导血管舒张的CPA在结肠炎小鼠中受损。CPA导致的ER钙耗尽诱导肠系膜动脉血管舒张，该过程由EDH机制介导并引发SOCE激活。CPA诱导的内皮依赖性舒张在结肠炎中受损，这可能会限制对肠黏膜的血液灌注。
