Intestinal barrier dysfunction in murine sickle cell disease is associated with small intestine neutrophilic inflammation, oxidative stress, and dysbiosis

• Type of Material: Article
• Authors: Caitlin V Lewis, Emory University; Hassan Sellak, Emory University; Mariem A Sawan, Emory University; Giji Joseph, Emory University; Trevor M Darby, Emory University; David VanInsberghe, Emory University; Crystal R Naudin, Emory University; David Archer, Emory University; Rheinallt Jones, Emory University; W. Robert Taylor, Emory University
• Language: English
• Date: 2023-05-01
• Publisher: Wiley Periodicals LLC
• Publication Version: Final Published Version
• Copyright Statement: © 2023 The Authors. FASEB BioAdvances published by Wiley Periodicals LLC on behalf of The Federation of American Societies for Experimental Biology.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1096/fba.2022-00121
• Title of Journal or Parent Work: FASEB BioAdvances
• Volume: 5
• Issue: 5
• Start Page: 199
• End Page: 210
• Keywords: oxidative stress; neutrophils; intestinal permeability; sickle cell disease; gut microbiome
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

The intestinal microbiome has emerged as a potential contributor to the severity of sickle cell disease (SCD). We sought to determine whether SCD mice exhibit intestinal barrier dysfunction, inflammation, and dysbiosis. Using the Townes humanized sickle cell mouse model, we found a 3-fold increase in intestinal permeability as assessed via FITC-dextran (4 kDa) assay in SS (SCD) mice compared to AA (wild type) mice (n = 4, p < 0.05). This was associated with 25 to 50% decreases in claudin-1, 3, and 15 and zonula occludens-1 gene expression (n = 8–10, p < 0.05) in the small intestine. Increased Ly6G staining demonstrated more neutrophils in the SS small intestine (3-fold, n = 5, p < 0.05) associated with increased expression of TNFα, IL-17A, CXCL1, and CD68 (2.5 to 5-fold, n = 7–10, p < 0.05). In addition, we observed 30 to 55% decreases in superoxide dismutase-1, glutathione peroxidase-1, and catalase antioxidant enzyme expression (n = 7–8, p < 0.05) concomitant to an increase in superoxide (2-fold, n = 4, p < 0.05). Importantly, all significant observations of a leaky gut phenotype and inflammation were limited to the small intestine and not observed in the colon. Finally, characterization of the composition of the microbiome within the small intestine revealed dysbiosis in SS mice compared to their AA littermates with 47 phyla to species-level significant alterations in amplicon sequence variants. We conclude that the intestinal barrier is compromised in SCD, associated with decreased gene expression of tight junction proteins, enhanced inflammation, oxidative stress, and gut microbiome dysbiosis, all specific to the small intestine.