Cunningham Kellie E, Vincent Garret, Sodhi Chhinder P, Novak Elizabeth A, Ranganathan Sarangarajan, Egan Charlotte E, Stolz Donna Beer, Rogers Matthew B, Firek Brian, Morowitz Michael J, Gittes George K, Zuckerbraun Brian S, Hackam David J, Mollen Kevin P
the Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213.
the Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, From the Division of Pediatric Surgery, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224.
J Biol Chem. 2016 May 6;291(19):10184-200. doi: 10.1074/jbc.M115.688812. Epub 2016 Mar 11.
Peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC1α) is the primary regulator of mitochondrial biogenesis and was recently found to be highly expressed within the intestinal epithelium. PGC1α is decreased in the intestinal epithelium of patients with inflammatory bowel disease, but its role in pathogenesis is uncertain. We now hypothesize that PGC1α protects against the development of colitis and helps to maintain the integrity of the intestinal barrier. We selectively deleted PGC1α from the intestinal epithelium of mice by breeding a PGC1α(loxP/loxP) mouse with a villin-cre mouse. Their progeny (PGC1α(ΔIEC) mice) were subjected to 2% dextran sodium sulfate (DSS) colitis for 7 days. The SIRT1 agonist SRT1720 was used to enhance PGC1α activation in wild-type mice during DSS exposure. Mice lacking PGC1α within the intestinal epithelium were more susceptible to DSS colitis than their wild-type littermates. Pharmacologic activation of PGC1α successfully ameliorated disease and restored mitochondrial integrity. These findings suggest that a depletion of PGC1α in the intestinal epithelium contributes to inflammatory changes through a failure of mitochondrial structure and function as well as a breakdown of the intestinal barrier, which leads to increased bacterial translocation. PGC1α induction helps to maintain mitochondrial integrity, enhance intestinal barrier function, and decrease inflammation.
过氧化物酶体增殖物激活受体γ共激活因子1α(PGC1α)是线粒体生物合成的主要调节因子,最近发现它在肠上皮细胞中高表达。在炎症性肠病患者的肠上皮细胞中,PGC1α表达降低,但其在发病机制中的作用尚不确定。我们现在假设,PGC1α可预防结肠炎的发生,并有助于维持肠道屏障的完整性。我们通过将PGC1α(loxP/loxP)小鼠与绒毛蛋白-cre小鼠杂交,选择性地从小鼠肠上皮细胞中删除PGC1α。它们的后代(PGC1α(ΔIEC)小鼠)接受2%葡聚糖硫酸钠(DSS)诱导的结肠炎处理7天。在DSS暴露期间,使用SIRT1激动剂SRT1720增强野生型小鼠中PGC1α的激活。肠上皮细胞中缺乏PGC1α的小鼠比其野生型同窝小鼠更容易患DSS结肠炎。PGC1α的药物激活成功改善了疾病并恢复了线粒体的完整性。这些发现表明,肠上皮细胞中PGC1α的缺失通过线粒体结构和功能的破坏以及肠道屏障的破坏导致炎症变化,进而导致细菌易位增加。诱导PGC1α有助于维持线粒体完整性、增强肠道屏障功能并减轻炎症。