*Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; †Institutes of Molecular Biology, Academia Sinica, Taipei, Taiwan; ‡Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan; §Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei, Taiwan; ‖Department of Integrated Diagnostics and Therapeutics, College of Medicine, National Taiwan University, Taipei, Taiwan; ¶Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan; **Bioinformatics and Biostatistics Core, Center of Genomic Medicine, National Taiwan University, Taipei, Taiwan; ††Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; ‡‡Department of Pathology and Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; §§Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Boston, Massachusetts; ‖‖UT Southwestern Medical Center, Dallas, Texas; and ¶¶Institutes of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
Inflamm Bowel Dis. 2017 Oct;23(10):1730-1740. doi: 10.1097/MIB.0000000000001250.
The integrity of the gut barrier in patients with inflammatory bowel disease is known to be impaired but the exact mechanisms remain mostly unknown. SHANK3 mutations are associated with autism, and patients with autism are known to have higher proportions of inflammatory bowel disease. Here, we explore the role of SHANK3 in inflammatory bowel disease, both in vivo and in vitro.
Dextran sulfate sodium colitis was induced in SHANK3 knockout mice. Transepithelial electrical resistance, paracellular permeability, and Salmonella invasion assays were used to evaluate epithelial barrier function, in vitro and in vivo. Expression of tight junction proteins, protein kinases, and MAP kinase phosphorylation changes were analyzed by immunoblotting after overexpression or knockdown of SHANK3 expression. SHANK3 expression in intestinal tissue from patients with Crohn's disease was analyzed by quantitative polymerase chain reaction and immunohistochemistry.
SHANK3 knockout mice were more susceptible to dextran sulfate sodium. SHANK3 knockout resulted in a leaky epithelial barrier phenotype, as demonstrated by decreased transepithelial electrical resistance, increased paracellular permeability, and increased Salmonella invasion. Overexpression of SHANK3 enhanced ZO-1 expression, and knockdown of SHANK3 resulted in decreased expression of ZO-1. Regulation of ZO-1 expression by SHANK3 seems to be mediated through a PKCε-dependent pathway. SHANK3 expression correlated with ZO-1 and PKCε in colonic tissue of patients with Crohn's disease.
The expression level of SHANK3 affects ZO-1 expression and the barrier function in intestinal epithelial cells. This may provide novel insights in Crohn's disease pathogenesis and treatment.
已知炎症性肠病患者的肠道屏障完整性受损，但确切机制仍知之甚少。SHANK3 突变与自闭症有关，而自闭症患者患炎症性肠病的比例较高。在这里，我们研究了 SHANK3 在炎症性肠病中的作用，包括在体内和体外。
在 SHANK3 敲除小鼠中诱导葡聚糖硫酸钠结肠炎。使用跨上皮电阻、旁细胞通透性和沙门氏菌侵袭试验评估体外和体内上皮屏障功能。通过过表达或敲低 SHANK3 表达后，通过免疫印迹分析紧密连接蛋白、蛋白激酶和 MAP 激酶磷酸化变化。通过定量聚合酶链反应和免疫组织化学分析克罗恩病患者肠道组织中的 SHANK3 表达。
SHANK3 敲除小鼠对葡聚糖硫酸钠更敏感。SHANK3 敲除导致上皮屏障通透性增加，表现为跨上皮电阻降低、旁细胞通透性增加和沙门氏菌侵袭增加。SHANK3 的过表达增强了 ZO-1 的表达，而 SHANK3 的敲低导致 ZO-1 的表达减少。SHANK3 通过 PKCε 依赖性途径调节 ZO-1 的表达。SHANK3 的表达与克罗恩病患者结肠组织中的 ZO-1 和 PKCε 相关。
SHANK3 的表达水平影响肠道上皮细胞中 ZO-1 的表达和屏障功能。这可能为克罗恩病的发病机制和治疗提供新的见解。
