Center of Gastrointestinal Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 2nd Zhongshan Road, Guangzhou 510080, PR China; Center of Gastric Cancer, Sun Yat-Sen University, 58 2nd Zhongshan Road, Guangzhou 510080, PR China.
Center of Gastrointestinal Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 2nd Zhongshan Road, Guangzhou 510080, PR China; Center of Gastric Cancer, Sun Yat-Sen University, 58 2nd Zhongshan Road, Guangzhou 510080, PR China.
Int Immunopharmacol. 2019 Feb;67:54-61. doi: 10.1016/j.intimp.2018.12.002. Epub 2018 Dec 7.
Complement activation is associated with regional inflammation during acute gastrointestinal injury (AGI). This study is designed to explore how intracellular C3 activation in Paneth cells (PCs) affects regeneration of intestinal epithelium during AGI. AGI was induced in wildtype C57BL/6 mice, with sham operation employed as control. Exogenous C3 (1 mg, I.P.) was applied at 6 h post-surgery. Intestinal crypts harvested from ileum were cultured with presence or absence of C3 (20 μg/ml), with small interfering RNA against BST1 and complement activation inhibitor selectively applied in vitro. The intestinal integrity, percentage of PCs and intestinal stem cells (ISCs) were evaluated. Importantly, cADPR, C3 fragments, and S6-related proteins were detected in PCs to inspect the mammalian target of rapamycin complex 1 (mTORC1) signaling. AGI caused breakdown of intestinal mucosa integrity and regional inflammation. Exogenous C3 by itself failed to promote the growth of intestinal epithelium, but distinctly enhanced the activity of PCs via intracellular activation, which subsequently supported the expansion of ISCs inside of intestinal crypts. Inhibition of C3 activation was associated with decreased expressions of S6, S6K1 and cADPR, with blocking BST1 found to depress cADPR only. Collectively, these data confirmed intracellular activation of C3 in PCs enhanced expansion of ISCs in response to acute injury. The mTORC1 signaling pathway in PCs contributed to this crosstalk during exogenous C3 treatment.
补体激活与急性胃肠损伤（AGI）期间的局部炎症有关。本研究旨在探讨 Paneth 细胞（PCs）内 C3 的细胞内激活如何影响 AGI 期间肠上皮的再生。在野生型 C57BL/6 小鼠中诱导 AGI，假手术作为对照。术后 6 小时给予外源性 C3（1mg，腹腔注射）。从回肠中采集肠隐窝进行培养，存在或不存在 C3（20μg/ml），体外选择性应用 BST1 和补体激活抑制剂的小干扰 RNA。评估肠完整性、PCs 和肠干细胞（ISCs）的百分比。重要的是，检测 PCs 中的 cADPR、C3 片段和 S6 相关蛋白，以检查哺乳动物雷帕霉素靶蛋白复合物 1（mTORC1）信号通路。AGI 导致肠黏膜完整性和局部炎症的破坏。外源性 C3 本身不能促进肠上皮的生长，但通过细胞内激活明显增强了 PCs 的活性，从而支持肠隐窝内 ISCs 的扩增。C3 激活的抑制与 S6、S6K1 和 cADPR 的表达减少有关，阻断 BST1 仅发现 cADPR 下调。总的来说，这些数据证实了 PCs 内 C3 的细胞内激活增强了对急性损伤的 ISCs 扩增。PCs 中的 mTORC1 信号通路有助于外源性 C3 治疗期间的这种串扰。
