1
|
Carneiro VL, Littlefield KM, Watson R, Palmer BE, Lozupone C. Inflammation-associated gut microbiome in postacute sequelae of SARS-CoV-2 points towards new therapeutic targets. Gut 2024; 73:376-378. [PMID: 36717218 PMCID: PMC10850647 DOI: 10.1136/gutjnl-2022-328757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/08/2023] [Indexed: 02/01/2023]
Affiliation(s)
| | - Katherine M Littlefield
- Department of Medicine, University of Colorado - Anschutz Medical Campus, Aurora, Colorado, USA
| | - Renee Watson
- Department of Medicine, University of Colorado - Anschutz Medical Campus, Aurora, Colorado, USA
| | - Brent E Palmer
- Department of Medicine, University of Colorado - Anschutz Medical Campus, Aurora, Colorado, USA
| | - Catherine Lozupone
- Department of Biomedical Informatics, University of Colorado - Anschutz Medical Campus, Aurora, Colorado, USA
| |
Collapse
|
2
|
Ng GZ, Menheniott TR, Every AL, Stent A, Judd LM, Chionh YT, Dhar P, Komen JC, Giraud AS, Wang TC, McGuckin MA, Sutton P. The MUC1 mucin protects against Helicobacter pylori pathogenesis in mice by regulation of the NLRP3 inflammasome. Gut 2016; 65:1087-99. [PMID: 26079943 DOI: 10.1136/gutjnl-2014-307175] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 03/11/2015] [Indexed: 12/16/2022]
Abstract
OBJECTIVES The mucin MUC1, best known for providing an epithelial barrier, is an important protective host factor in both humans and mice during Helicobacter pylori pathogenesis. This study aimed to identify the long-term consequences of MUC1 deficiency on H. pylori pathogenesis and the mechanism by which MUC1 protects against H. pylori gastritis. DESIGN Wildtype and Muc1(-/-) mice were infected for up to 9 months, and the gastric pathology, immunological response and epigenetic changes assessed. The effects of MUC1 on the inflammasome, a potent inflammatory pathway, were examined in macrophages and H. pylori-infected mice deficient in both MUC1 and inflammasome components. RESULTS Muc1(-/-) mice began to die 6 months after challenge, indicating Muc1 deficiency made H. pylori a lethal infection. Surprisingly, chimaeric mouse infections revealed MUC1 expression by haematopoietic-derived immune cells limits H. pylori-induced gastritis. Gastritis in infected Muc1(-/-) mice was associated with elevated interleukin (IL)-1β and epigenetic changes in their gastric mucosa similar to those in transgenic mice overexpressing gastric IL-1β, implicating MUC1 regulation of an inflammasome. In support of this, infected Muc1(-/-)Casp1(-/-) mice did not develop severe gastritis. Further, MUC1 regulated Nlrp3 expression via an nuclear factor (NF)-κB-dependent pathway and reduced NF-κB pathway activation via inhibition of IRAK4 phosphorylation. The importance of this regulation was proven using Muc1(-/-)Nlrp3(-/-) mice, which did not develop severe gastritis. CONCLUSIONS MUC1 is an important, previously unidentified negative regulator of the NLRP3 inflammasome. H. pylori activation of the NLRP3 inflammasome is normally tightly regulated by MUC1, and loss of this critical regulation results in the development of severe pathology.
Collapse
Affiliation(s)
- Garrett Z Ng
- Centre for Animal Biotechnology, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Trevelyan R Menheniott
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Alison L Every
- Centre for Animal Biotechnology, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew Stent
- Centre for Animal Biotechnology, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Louise M Judd
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Yok Teng Chionh
- Centre for Animal Biotechnology, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Poshmaal Dhar
- Centre for Animal Biotechnology, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Jasper C Komen
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Andrew S Giraud
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Timothy C Wang
- Division of Digestive and Liver Diseases, Department of Medicine, Columbia University, New York, USA
| | - Michael A McGuckin
- Mucosal Diseases Program, Mater Research Institute-University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Philip Sutton
- Centre for Animal Biotechnology, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| |
Collapse
|
3
|
Johansson MEV, Gustafsson JK, Holmén-Larsson J, Jabbar KS, Xia L, Xu H, Ghishan FK, Carvalho FA, Gewirtz AT, Sjövall H, Hansson GC. Bacteria penetrate the normally impenetrable inner colon mucus layer in both murine colitis models and patients with ulcerative colitis. Gut 2014; 63:281-91. [PMID: 23426893 PMCID: PMC3740207 DOI: 10.1136/gutjnl-2012-303207] [Citation(s) in RCA: 647] [Impact Index Per Article: 64.7] [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] [Indexed: 02/06/2023]
Abstract
OBJECTIVE The inner mucus layer in mouse colon normally separates bacteria from the epithelium. Do humans have a similar inner mucus layer and are defects in this mucus layer a common denominator for spontaneous colitis in mice models and ulcerative colitis (UC)? METHODS AND RESULTS The colon mucus layer from mice deficient in Muc2 mucin, Core 1 O-glycans, Tlr5, interleukin 10 (IL-10) and Slc9a3 (Nhe3) together with that from dextran sodium sulfate-treated mice was immunostained for Muc2, and bacterial localisation in the mucus was analysed. All murine colitis models revealed bacteria in contact with the epithelium. Additional analysis of the less inflamed IL-10(-/-) mice revealed a thicker mucus layer than wild-type, but the properties were different, as the inner mucus layer could be penetrated both by bacteria in vivo and by fluorescent beads the size of bacteria ex vivo. Clear separation between bacteria or fluorescent beads and the epithelium mediated by the inner mucus layer was also evident in normal human sigmoid colon biopsy samples. In contrast, mucus on colon biopsy specimens from patients with UC with acute inflammation was highly penetrable. Most patients with UC in remission had an impenetrable mucus layer similar to that of controls. CONCLUSIONS Normal human sigmoid colon has an inner mucus layer that is impenetrable to bacteria. The colon mucus in animal models that spontaneously develop colitis and in patients with active UC allows bacteria to penetrate and reach the epithelium. Thus colon mucus properties can be modulated, and this suggests a novel model of UC pathophysiology.
Collapse
Affiliation(s)
- Malin E V Johansson
- Department of Medical Biochemistry, University of Gothenburg, , Gothenburg, Sweden
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|