DRG1 Maintains Intestinal Epithelial Cell Junctions and Barrier Function by Regulating RAC1 Activity in Necrotizing Enterocolitis

• Published in: Digestive diseases and sciences Vol. 66; no. 12; pp. 4237 - 4250
• Main Authors: Lu, Li, Xu, Weijue, Liu, Jiangbin, Chen, Liping, Hu, Shaohua, Sheng, Qingfeng, Zhang, Minghua, Lv, Zhibao
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2021; Springer; Springer Nature B.V
• Subjects: Analysis; Antibiotics; Binding proteins; Biochemistry; Enterocolitis, Neonatal necrotizing; Enterocolitis, Pseudomembranous; Gastroenterology; Gastrointestinal diseases; Hepatology; Immunohistochemistry; Investigations; Kinases; Laboratories; Mass spectrometry; Medicine; Medicine & Public Health; Necrosis; Newborn babies; Oncology; Original Article; Pathogenesis; Permeability; Protein binding; Proteins; Risk factors; Road construction industry; Scientific imaging; Small intestine; Transplant Surgery; Cell–cell junction; DRG1; Necrotizing enterocolitis; Intestinal barrier permeability; RAC1; E-cadherin
• ISSN: 0163-2116; 1573-2568
• DOI: 10.1007/s10620-020-06812-3

Background An immature intestine is a high-risk factor for necrotizing enterocolitis (NEC), which is a serious intestinal disease in newborns. The regulation of developmentally regulated GTP-binding protein 1 (DRG1) during organ development suggests a potential role of DRG1 in the maturation process of the intestine. Aim To illustrate the function of DRG1 during the pathogenesis of NEC. Methods DRG1 expression in the intestine was measured using immunohistochemistry and q-PCR. Immunoprecipitation coupled with mass spectrometry was used to identify the interacting proteins of DRG1. The biological functions of the potential interactors were annotated with the Database for Annotation, Visualization and Integrated Discovery. Caco2 and FHs74Int cells with stable DRG1 silencing or overexpression were used to investigate the influence of DRG1 on cell junctions and intestinal barrier permeability and to elucidate the downstream mechanism. Results DRG1 was constitutively expressed during the intestinal maturation process but significantly decreased in the ileum in the context of NEC. Protein interaction analysis revealed that DRG1 was closely correlated with cell junctions. DRG1 deficiency destabilized the E-cadherin and occludin proteins near the cell membrane and increased the permeability of the epithelial cell monolayer, while DRG1 overexpression prevented lipopolysaccharide-induced disruption of E-cadherin and occludin expression and cell monolayer integrity. Further investigation suggested that DRG1 maintained cell junctions, especially adherens junctions, by regulating RAC1 activity, and RAC1 inhibition with NSC23766 attenuated intestinal injury and led to improved barrier integrity in experimental NEC. Conclusions Our findings illustrate the mechanism underlying the effect of DRG1 deficiency on epithelial cell permeability regulation and provide evidence supporting the application of RAC1 inhibitors for protection against NEC.