Department of Pediatric Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Division of Pediatric Gastroenterology and Nutrition, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
FASEB J. 2024 Aug 15;38(15):e23847. doi: 10.1096/fj.202400827R.
Intestinal failure-associated liver disease (IFALD) is a serious complication of long-term parenteral nutrition in patients with short bowel syndrome (SBS), and is the main cause of death in SBS patients. Prevention of IFALD is one of the major challenges in the treatment of SBS. Impairment of intestinal barrier function is a key factor in triggering IFALD, therefore promoting intestinal repair is particularly important. Intestinal repair mainly relies on the function of intestinal stem cells (ISC), which require robust mitochondrial fatty acid oxidation (FAO) for self-renewal. Herein, we report that aberrant LGR5+ ISC function in IFALD may be attributed to impaired farnesoid X receptor (FXR) signaling, a transcriptional factor activated by steroids and bile acids. In both surgical biopsies and patient-derived organoids (PDOs), SBS patients with IFALD represented lower population of LGR5+ cells and decreased FXR expression. Moreover, treatment with T-βMCA in PDOs (an antagonist for FXR) dose-dependently reduced the population of LGR5+ cells and the proliferation rate of enterocytes, concomitant with decreased key genes involved in FAO including CPT1a. Interestingly, however, treatment with Tropifexor in PDOs (an agonist for FXR) only enhanced FAO capacity, without improvement in ISC function and enterocyte proliferation. In conclusion, these findings suggested that impaired FXR may accelerate the depletion of LGR5 + ISC population through disrupted FAO processes, which may serve as a new potential target of preventive interventions against IFALD for SBS patients.
肠衰竭相关肝病(IFALD)是短肠综合征(SBS)患者长期肠外营养的严重并发症,也是 SBS 患者死亡的主要原因。IFALD 的预防是 SBS 治疗的主要挑战之一。肠屏障功能的损害是触发 IFALD 的关键因素,因此促进肠修复尤为重要。肠修复主要依赖于肠干细胞(ISC)的功能,ISC 的自我更新需要强大的线粒体脂肪酸氧化(FAO)。在此,我们报告 IFALD 中异常的 LGR5+ISC 功能可能归因于法尼醇 X 受体(FXR)信号转导受损,FXR 是一种被类固醇和胆汁酸激活的转录因子。在手术活检和患者来源的类器官(PDO)中,IFALD 的 SBS 患者代表着更少的 LGR5+细胞和降低的 FXR 表达。此外,PDO 中 T-βMCA 的治疗(FXR 的拮抗剂)以剂量依赖性方式降低 LGR5+细胞的数量和肠细胞的增殖率,同时减少包括 CPT1a 在内的参与 FAO 的关键基因。有趣的是,然而,PDO 中 Tropifexor 的治疗(FXR 的激动剂)仅增强了 FAO 能力,而没有改善 ISC 功能和肠细胞增殖。总之,这些发现表明,受损的 FXR 可能通过破坏 FAO 过程加速 LGR5+ISC 群体的耗竭,这可能成为预防 SBS 患者 IFALD 的新的潜在干预靶点。