Department of General Surgery, Xuanwu Hospital Capital Medical University, Beijing 100053, China.
Center for Biomarker Discovery and Validation, National Infrastructures for Translational Medicine (PUMCH), Institute of Clinical Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, 100730, China; State Key Laboratory of Complex, Severe, and Rare Diseases, Institute of Clinical Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100730, China; Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, 100730, China.
Pancreatology. 2024 Jun;24(4):528-537. doi: 10.1016/j.pan.2024.04.001. Epub 2024 Apr 5.
Store-operated Ca entry (SOCE) mediated by ORAI1 channel plays a crucial role in acute pancreatitis (AP). Macrophage is an important regulator in amplifying pancreatic tissue damage, but little is known about the role of ORAI1 in macrophages. In this study, we examined the effects of macrophage-specific ORAI1 on pancreatic tissue damage in AP.
Myeloid-specific Orai1 deficient mice was generated by crossing a LysM-Cre mouse line with Orai1 mice. Bone marrow-derived macrophages (BMDMs) were isolated, cultured, and stimulated to induce M1 or M2 macrophage polarization. Intracellular Ca signals were measured by time-lapse confocal microscope imaging, with a Ca indicator (Fluo 4). Experimental AP was induced by hourly intraperitoneal injections of caerulein or retrograde biliopancreatic infusion of sodium taurocholate. Pancreatic tissue damage was assessed by histopathological scoring and immunostaining. Sepsis was induced by intraperitoneal injection of lipopolysaccharide; organ damage and serum pro-inflammatory cytokines were measured.
Myeloid-specific Orai1 deletion exhibited minimal effect on SOCE in M0 macrophages and promoted M2 macrophage polarization ex vivo. Myeloid-specific Orai1 deletion did not affect pancreatic tissue damage, nor neutrophil or macrophage infiltration in two models of AP. Similarly, myeloid-specific Orai1 deletion did not influence overall survival rate in a model of sepsis, nor lung, kidney, and liver damage; while serum pro-inflammatory cytokines, including IL-6, TNF-α, and IL-1β were higher in Orai1 mice, but were largely reduced in mice with Orai1 inhibitor.
Our data suggest that ORAI1 may not be a predominant SOCE channel in macrophages and play a limited role in mediating pancreatic tissue damage in AP.
由 ORAI1 通道介导的储存操纵钙内流（SOCE）在急性胰腺炎（AP）中发挥着关键作用。巨噬细胞是放大胰腺组织损伤的重要调节剂，但 ORAI1 在巨噬细胞中的作用知之甚少。在这项研究中，我们研究了巨噬细胞特异性 ORAI1 在 AP 中对胰腺组织损伤的影响。
通过 LysM-Cre 小鼠与 Orai1 小鼠杂交，生成骨髓细胞特异性 Orai1 缺陷小鼠。分离、培养和刺激骨髓来源的巨噬细胞（BMDM），以诱导 M1 或 M2 巨噬细胞极化。通过时间 lapse 共聚焦显微镜成像，使用钙指示剂（Fluo 4）测量细胞内钙信号。通过每小时腹腔内注射 CA 或逆行胰胆管内注入牛磺胆酸钠诱导实验性 AP。通过组织病理学评分和免疫染色评估胰腺组织损伤。通过腹腔内注射脂多糖诱导脓毒症；测量器官损伤和血清促炎细胞因子。
骨髓细胞特异性 Orai1 缺失对 M0 巨噬细胞中的 SOCE 影响不大，并促进了 ex vivo 中 M2 巨噬细胞极化。骨髓细胞特异性 Orai1 缺失不影响两种 AP 模型中的胰腺组织损伤，也不影响中性粒细胞或巨噬细胞浸润。同样，骨髓细胞特异性 Orai1 缺失不影响脓毒症模型中的总生存率，也不影响肺、肾和肝损伤；而 Orai1 小鼠的血清促炎细胞因子（包括 IL-6、TNF-α 和 IL-1β）较高，但在 Orai1 抑制剂处理的小鼠中则大大降低。
我们的数据表明，ORAI1 可能不是巨噬细胞中主要的 SOCE 通道，在介导 AP 中的胰腺组织损伤中发挥有限作用。
