Functional characterization of SLC26A3 c.392C>G (p.P131R) mutation in intestinal barrier function using CRISPR/CAS9-created cell models

• Published in: Cell & bioscience 2019-05, Vol.9 (1), p.40-40, Article 40
• Main Authors: Zhang, Nini, Heruth, Daniel P, Wu, Weibin, Zhang, Li Qin, Nsumu, Marianne N, Shortt, Katherine, Li, Kelvin, Jiang, Xun, Wang, Baoxi, Friesen, Craig, Li, Ding-You, Ye, Shui Qing
• Format: Article
• Language: English
• Subjects: Amino acids; Cell culture; Chloride transport; Congenital diseases; CRISPR; Cystic fibrosis; Dehydration; Diarrhea; Epithelial cell; Gene polymorphism; Genomes; Hereditary diseases; Infant mortality; Inflammation; Inflammatory bowel disease; Intestinal epithelium; Intestine; Metabolism; Molecular modelling; Mutation; Pathogenesis; Permeability; Single-nucleotide polymorphism; Single-nucleotide polymorphism (SNP); Small intestine; Tumor necrosis factor-TNF; Ubiquitination; Zonula occludens-1 protein
• ISSN: 2045-3701; 2045-3701
• DOI: 10.1186/s13578-019-0303-1

Congenital chloride diarrhea (CCD) in a newborn is a rare autosomal recessive disorder with life-threatening complications, requiring early diagnostics and treatment to prevent severe dehydration and infant mortality. SLC26A3 rs386833481 (c.392C>G; p.P131R) gene polymorphism is an important genetic determinant of CCD. Here, we report the influence of the non-synonymous SLC26A3 variant rs386833481 gene polymorphism on the function of the epithelial barrier and the potential mechanisms of these effects. We found that P131R-SLC26A3 increased dysfunction of the epithelial barrier compared with wild type SLC26A3 in human colonic Caco-2 and mouse colonic CMT-93 cells. When P131R-SLC26A3 was subsequently reverted to wild type, the epithelial barrier function was restored similar to wild type cells. Further study demonstrated that variant P131R-SLC26A3 disrupts function of epithelial barrier through two distinct molecular mechanisms: (a) decreasing SLC26A3 expression through a ubiquitination pathway and (b) disrupting a key interaction with its partner ZO-1/CFTR, thereby increasing the epithelial permeability. Our study provides an important insight of SLC26A3 SNPs in the regulation of the epithelial permeability and indicates that SLC26A3 rs386833481 is likely a causative mutation in the dysfunction of epithelial barrier of CCD, and correction of this SNP or increasing SLC26A3 function could be therapeutically beneficial for chronic diarrhea diseases.