TY - JOUR
T1 - A Novel Role of SLC26A3 in the Maintenance of Intestinal Epithelial Barrier Integrity
AU - Kumar, Anoop
AU - Priyamvada, Shubha
AU - Ge, Yong
AU - Jayawardena, Dulari
AU - Singhal, Megha
AU - Anbazhagan, Arivarasu N.
AU - Chatterjee, Ishita
AU - Dayal, Aneal
AU - Patel, Mitul
AU - Zadeh, Kimia
AU - Saksena, Seema
AU - Alrefai, Waddah A.
AU - Gill, Ravinder K.
AU - Zadeh, Mojgan
AU - Zhao, Ni
AU - Mohamadzadeh, Mansour
AU - Dudeja, Pradeep K.
N1 - Publisher Copyright:
© 2021
PY - 2021/3
Y1 - 2021/3
N2 - Background & Aims: The down-regulated in adenoma (DRA) protein, encoded by SLC26A3, a key intestinal chloride anion exchanger, has recently been identified as a novel susceptibility gene for inflammatory bowel disease (IBD). However, the mechanisms underlying the increased susceptibility to inflammation induced by the loss of DRA remain elusive. Compromised barrier is a key event in IBD pathogenesis. The current studies were undertaken to elucidate the impact of DRA deficiency on epithelial barrier integrity and to define underlying mechanisms. Methods: Wild-type and DRA-knockout (KO) mice and crypt-derived colonoids were used as models for intestinal epithelial response. Paracellular permeability was measured by using fluorescein isothiocyanate–dextran flux. Immunoblotting, immunofluorescence, immunohistochemistry, and ribonucleoprotein immunoprecipitation assays were performed. Gut microbiome analysis was conducted to investigate the impact of DRA deficiency on gut microbial communities. Results: DRA-KO mice exhibited an increased colonic paracellular permeability with significantly decreased levels of tight junction/adherens junction proteins, including ZO-1, occludin, and E-cadherin. A similar expression pattern of occludin and E-cadherin was observed in colonoids derived from DRA-KO mice and short hairpin RNA–mediated DRA knockdown in Caco-2 cells. Microbial analysis showed gut dysbiosis in DRA-KO mice. However, cohousing studies showed that dysbiosis played only a partial role in maintaining tight junction protein expression. Furthermore, our results showed increased binding of RNA-binding protein CUGBP1 with occludin and E-cadherin genes in DRA-KO mouse colon, suggesting that posttranscriptional mechanisms play a key role in gut barrier dysfunction. Conclusions: To our knowledge, our studies demonstrate a novel role of DRA in maintaining the intestinal epithelial barrier function and potential implications of its dysregulation in IBD pathogenesis.
AB - Background & Aims: The down-regulated in adenoma (DRA) protein, encoded by SLC26A3, a key intestinal chloride anion exchanger, has recently been identified as a novel susceptibility gene for inflammatory bowel disease (IBD). However, the mechanisms underlying the increased susceptibility to inflammation induced by the loss of DRA remain elusive. Compromised barrier is a key event in IBD pathogenesis. The current studies were undertaken to elucidate the impact of DRA deficiency on epithelial barrier integrity and to define underlying mechanisms. Methods: Wild-type and DRA-knockout (KO) mice and crypt-derived colonoids were used as models for intestinal epithelial response. Paracellular permeability was measured by using fluorescein isothiocyanate–dextran flux. Immunoblotting, immunofluorescence, immunohistochemistry, and ribonucleoprotein immunoprecipitation assays were performed. Gut microbiome analysis was conducted to investigate the impact of DRA deficiency on gut microbial communities. Results: DRA-KO mice exhibited an increased colonic paracellular permeability with significantly decreased levels of tight junction/adherens junction proteins, including ZO-1, occludin, and E-cadherin. A similar expression pattern of occludin and E-cadherin was observed in colonoids derived from DRA-KO mice and short hairpin RNA–mediated DRA knockdown in Caco-2 cells. Microbial analysis showed gut dysbiosis in DRA-KO mice. However, cohousing studies showed that dysbiosis played only a partial role in maintaining tight junction protein expression. Furthermore, our results showed increased binding of RNA-binding protein CUGBP1 with occludin and E-cadherin genes in DRA-KO mouse colon, suggesting that posttranscriptional mechanisms play a key role in gut barrier dysfunction. Conclusions: To our knowledge, our studies demonstrate a novel role of DRA in maintaining the intestinal epithelial barrier function and potential implications of its dysregulation in IBD pathogenesis.
KW - Down-regulated in Adenoma
KW - Gut Microbiota
KW - Inflammatory Bowel Disease
KW - Intestinal Chloride Transporter
UR - https://www.scopus.com/pages/publications/85102147272
UR - https://www.scopus.com/pages/publications/85102147272#tab=citedBy
U2 - 10.1053/j.gastro.2020.11.008
DO - 10.1053/j.gastro.2020.11.008
M3 - Article
C2 - 33189700
AN - SCOPUS:85102147272
SN - 0016-5085
VL - 160
SP - 1240-1255.e3
JO - Gastroenterology
JF - Gastroenterology
IS - 4
ER -