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Wahlang B, Alexander NC, Li X, Rouchka EC, Kirpich IA, Cave MC. Polychlorinated biphenyls altered gut microbiome in CAR and PXR knockout mice exhibiting toxicant-associated steatohepatitis. Toxicol Rep 2021; 8:536-547. [PMID: 33777700 PMCID: PMC7985695 DOI: 10.1016/j.toxrep.2021.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 12/12/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with non-alcoholic fatty liver disease (NAFLD). Previously, we demonstrated that the PCB mixture, Aroclor1260, exacerbated NAFLD, reflective of toxicant-associated steatohepatitis, in diet-induced obese mice, in part through pregnane-xenobiotic receptor (PXR) and constitutive androstane receptor (CAR) activation. Recent studies have also reported PCB-induced changes in the gut microbiome that consequently impact NAFLD. Therefore, the objective of this study is to examine PCB effects on the gut-liver axis and characterize the role of CAR and PXR in microbiome alterations. C57Bl/6 (wildtype, WT), CAR and PXR knockout mice were fed a high fat diet and exposed to Aroclor1260 (20 mg/kg, oral gavage, 12 weeks). Metagenomics analysis of cecal samples revealed that CAR and/or PXR ablation increased bacterial alpha diversity regardless of exposure status. CAR and PXR ablation also increased bacterial composition (beta diversity) versus WT; Aroclor1260 altered beta diversity only in WT and CAR knockouts. Distinct changes in bacterial abundance at different taxonomic levels were observed between WT and knockout groups; however Aroclor1260 had modest effects on bacterial abundance within each genotype. Notably, both knockout groups displayed increased Actinobacteria and Verrucomicrobia abundance. In spite of improved bacterial diversity, the knockout groups however failed to show protection from PCB-induced hepato- and intestinal- toxicity including decreased mRNA levels of ileal permeability markers (occludin, claudin3). In summary, CAR and PXR ablation significantly altered gut microbiome in diet-induced obesity while Aroclor1260 compromised intestinal integrity in knockout mice, implicating interactions between PCBs and CAR, PXR on the gut-liver axis.
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Key Words
- ACHS, anniston community healthy survey
- AhR, arylhydrocarbon receptor
- Aroclor1260
- CAR, constitutive androstane receptor
- Camp, cathelicidin anti-microbial peptide
- Cdh5, adhesion molecule VE-cadherin
- Cldn, claudin
- Fasn, fatty acid synthase
- Fgf15, fibroblast growth factor 15
- Gut-liver
- HFD, high fat diet
- HOMA, homeostasis model assessment
- IBD, inflammatory bowel diseases
- LDA, linear discriminant analysis
- LEfSe, linear discriminant analysis effect size
- Microbiome
- Muc, mucin
- NAFLD
- NAFLD, nonalcoholic fatty liver disease
- NASH, nonalcoholic steatohepatitis
- OTU, operational taxonomic unit
- Ocln, occludin
- PCBs
- PCBs, polychlorinated biphenyls
- PXR, pregnane-xenobiotic receptor
- Pck1, phosphoenolpyruvate carboxykinase 1
- Ppara, peroxisome-proliferator activated receptor alpha
- RER, respiratory exchange rate
- Reg3g, regenerating islet-derived protein 3-gamma
- TASH
- TASH, toxicant-associated steatohepatitis
- Tff3, trefoil factor 3
- Tjp1, tight junction protein 1
- Tnfa, tumor necrosis factor
- WT, wildtype
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Affiliation(s)
- Banrida Wahlang
- UofL Superfund Research Center, University of Louisville, Louisville, KY, USA
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA
- Department of Pharmacology & Toxicology, School of Medicine, University of Louisville, Louisville, KY, USA
| | | | - Xiaohong Li
- Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, USA
- KBRIN Bioinformatics Core, University of Louisville, Louisville, KY, USA
| | - Eric C. Rouchka
- KBRIN Bioinformatics Core, University of Louisville, Louisville, KY, USA
- Department of Computer Science and Engineering, J.B. Speed School of Engineering, University of Louisville, Louisville, KY, USA
| | - Irina A. Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA
- Department of Pharmacology & Toxicology, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Matthew C. Cave
- UofL Superfund Research Center, University of Louisville, Louisville, KY, USA
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA
- Department of Pharmacology & Toxicology, School of Medicine, University of Louisville, Louisville, KY, USA
- Department of Biochemistry & Molecular Genetics, School of Medicine, University of Louisville, Louisville, KY, USA
- Robley Rex Veterans Affairs Medical Center, Louisville, KY, USA
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Agoston AT, Pham TH, Odze RD, Wang DH, Das KM, Spechler SJ, Souza RF. Columnar-Lined Esophagus Develops via Wound Repair in a Surgical Model of Reflux Esophagitis. Cell Mol Gastroenterol Hepatol 2018; 6:389-404. [PMID: 30186929 PMCID: PMC6122432 DOI: 10.1016/j.jcmgh.2018.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 06/19/2018] [Indexed: 01/11/2023]
Abstract
BACKGROUND & AIMS After esophagojejunostomy, rodents develop reflux esophagitis and a columnar-lined esophagus with features of Barrett's metaplasia. This rodent columnar-lined esophagus has been proposed to develop from cellular reprogramming of progenitor cells, but studies on early columnar-lined esophagus development are lacking. We performed a systematic, histologic, and immunophenotypic analysis of columnar-lined esophagus development in rats after esophagojejunostomy. METHODS At various times after esophagojejunostomy in 52 rats, the esophagus was removed and tissue sections were evaluated for type, location, and length of columnar lining. Molecular characteristics were evaluated by immunohistochemistry and immunofluorescence. RESULTS At week 2, ulceration was seen in esophageal squamous epithelium, starting distally at the esophagojejunostomy anastomosis. Re-epithelialization of the distal ulcer segment occurred via proliferation and expansion of immature-appearing glands budding directly off jejunal crypts, characteristic of wound healing. The columnar-lined esophagus's immunoprofile was similar to jejunal crypt epithelium, and columnar-lined esophagus length increased significantly from 0.15 mm (±0.1 SEM) at 2 weeks to 5.22 mm (±0.37) at 32 weeks. Neoglands were found within esophageal ulcer beds, and spindle-shaped cells expressing epithelial-mesenchymal transition markers were found at the columnar-lined esophagus's leading edge. Only proliferative squamous epithelium was found at the proximal ulcer border. CONCLUSIONS After esophagojejunostomy in rats, metaplastic columnar-lined esophagus develops via a wound healing process that does not appear to involve cellular reprogramming of progenitor cells. This process involves EMT-associated migration of jejunal cells into the esophagus, where they likely have a competitive advantage over squamous cells in the setting of ongoing gastroesophageal reflux disease.
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Affiliation(s)
- Agoston T. Agoston
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Thai H. Pham
- Department of Surgery, VA North Texas Health Care System, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Robert D. Odze
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - David H. Wang
- Department of Medicine, VA North Texas Health Care System, University of Texas Southwestern Medical Center, Dallas, Texas,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Kiron M. Das
- Division of Gastroenterology, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Stuart J. Spechler
- Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center, Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas
| | - Rhonda F. Souza
- Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center, Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas,Correspondence Address correspondence to: Rhonda F. Souza, MD, Center for Esophageal Research, Baylor University Medical Center, 2 Hoblitzelle, Suite 250, 3500 Gaston Avenue, Dallas, Texas 75246.
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