1
|
Holers VM, Demoruelle KM, Buckner JH, James EA, Firestein GS, Robinson WH, Steere AC, Zhang F, Norris JM, Kuhn KA, Deane KD. Distinct mucosal endotypes as initiators and drivers of rheumatoid arthritis. Nat Rev Rheumatol 2024; 20:601-613. [PMID: 39251771 DOI: 10.1038/s41584-024-01154-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2024] [Indexed: 09/11/2024]
Abstract
Rheumatoid arthritis (RA) is a potentially devastating autoimmune disease. The great majority of patients with RA are seropositive for anti-citrullinated protein antibodies (ACPAs), rheumatoid factors, or other autoantibodies. The onset of clinically apparent inflammatory arthritis meeting classification criteria (clinical RA) is preceded by ACPA seropositivity for an average of 3-5 years, a period that is designated as 'at-risk' of RA for ACPA-positive individuals who do not display signs of arthritis, or 'pre-RA' for individuals who are known to have progressed to developing clinical RA. Prior studies of individuals at-risk of RA have associated pulmonary mucosal inflammation with local production of ACPAs and rheumatoid factors, leading to development of the 'mucosal origins hypothesis'. Recent work now suggests the presence of multiple distinct mucosal site-specific mechanisms that drive RA evolution. Indicatively, subsets of individuals at-risk of RA and patients with RA harbour a faecal bacterial strain that has exhibited arthritogenic activity in animal models and that favours T helper 17 (TH17) cell responses in patients. Periodontal inflammation and oral microbiota have also been suggested to promote the development of arthritis through breaches in the mucosal barrier. Herein, we argue that mucosal sites and their associated microbial strains can contribute to RA evolution via distinct pathogenic mechanisms, which can be considered causal mucosal endotypes. Future therapies instituted for prevention in the at-risk period, or, perhaps, during clinical RA as therapeutics for active arthritis, will possibly have to address these individual mechanisms as part of precision medicine approaches.
Collapse
Affiliation(s)
- V Michael Holers
- Division of Rheumatology, University of Colorado Denver, Aurora, CO, USA.
| | | | | | | | - Gary S Firestein
- Division of Rheumatology, Allergy and Immunology, University of California San Diego, La Jolla, CA, USA
| | - William H Robinson
- Division of Immunology and Rheumatology, Stanford University, Stanford, CA, USA
- VA Palo Alto Health Care System, Palo Alto, CA, USA
| | - Allen C Steere
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Fan Zhang
- Division of Rheumatology, University of Colorado Denver, Aurora, CO, USA
| | - Jill M Norris
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA
| | - Kristine A Kuhn
- Division of Rheumatology, University of Colorado Denver, Aurora, CO, USA
| | - Kevin D Deane
- Division of Rheumatology, University of Colorado Denver, Aurora, CO, USA
| |
Collapse
|
2
|
Su X, Wang X, Zhang X, Sun Y, Jia Y. β-Indole-3-acetic acid attenuated collagen-induced arthritis through reducing the ubiquitination of Foxp3 via the AhR-TAZ-Tip60 pathway. Immunol Res 2024; 72:741-753. [PMID: 38630408 DOI: 10.1007/s12026-024-09480-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/09/2024] [Indexed: 08/28/2024]
Abstract
Massive evidence shows that intestinal tryptophan metabolites affected by intestinal flora can modulate the progression of rheumatoid arthritis (RA). However, the effects and mechanisms of intestinal tryptophan metabolites on RA are not yet detailed. Herein, we investigated the protective effects of intestinal tryptophan metabolites on RA and its detailed mechanisms. In this study, the collagen-induced arthritis (CIA) rat model was established. Based on metabolomics analysis, the contents of β-indole-3-acetic acid (IAA), indolylpropionic acid, and indole-3-β-acrylic acid in the sera of CIA rats were significantly less compared with those of the normal rats. Under the condition of Treg or Th17 cell differentiation, IAA significantly promoted the differentiation and activation of Treg cells instead of Th17 cells. Intestinal tryptophan metabolites are well-known endogenic ligands of aryl hydrocarbon receptor (AhR). Not surprisingly, IAA increased the level of Foxp3 through activating the AhR pathway. Interestingly, IAA had little impact on the level of Foxp3 mRNA, but reducing the ubiquitination and degradation of Foxp3. Mechanically, IAA reduced the expression of the transcriptional coactivator TAZ, which was almost completely reversed by either AhR antagonist CH223191 or siRNA. In vitro, IAA decreased the combination of TAZ and the histone acetyltransferase Tip60, while it increased the combination of Tip60 and Foxp3. In CIA rats, oral administration of IAA increased the number of Treg cells and relieved the inflammation. A combined use with CH223191 almost abolished the effect of IAA. Taken together, IAA attenuated CIA by promoting the differentiation of Treg cells through reducing the ubiquitination of Foxp3 via the AhR-TAZ-Tip60 pathway.
Collapse
Affiliation(s)
- Xiaoran Su
- Department of Chinese Medicine, Hebei University of Chinese Medicine, Shijiazhuang, 050200, China
| | - Xinliu Wang
- Department of Integrative Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang, 050200, China
| | - Xin Zhang
- Department of Integrative Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang, 050200, China
| | - Yajie Sun
- Department of Chinese Medicine, Hebei University of Chinese Medicine, Shijiazhuang, 050200, China
| | - Yugai Jia
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, 050200, China.
- Hebei International Cooperation Center for Ion Channel Function and Innovative Traditional Chinese Medicine, Shijiazhuang, 050091, China.
| |
Collapse
|
3
|
Garcia AC, Six N, Ma L, Morel L. Intersection of the microbiome and immune metabolism in lupus. Immunol Rev 2024; 325:77-89. [PMID: 38873851 PMCID: PMC11338729 DOI: 10.1111/imr.13360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Systemic lupus erythematosus is a complex autoimmune disease resulting from a dysregulation of the immune system that involves gut dysbiosis and an altered host cellular metabolism. This review highlights novel insights and expands on the interactions between the gut microbiome and the host immune metabolism in lupus. Pathobionts, invasive pathogens, and even commensal microbes, when in dysbiosis, can all trigger and modulate immune responses through metabolic reprogramming. Changes in the microbiota's global composition or individual taxa may trigger a cascade of metabolic changes in immune cells that may, in turn, reprogram their functions. Factors contributing to dysbiosis include changes in intestinal hypoxia, competition for glucose, and limited availability of essential nutrients, such as tryptophan and metal ions, all of which can be driven by host metabolism changes. Conversely, the accumulation of some host metabolites, such as itaconate, succinate, and free fatty acids, could further influence the microbial composition and immune responses. Overall, mounting evidence supports a bidirectional relationship between host immunometabolism and the microbiota in lupus pathogenesis.
Collapse
Affiliation(s)
- Abigail Castellanos Garcia
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Natalie Six
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Longhuan Ma
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Laurence Morel
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, Texas, USA
| |
Collapse
|
4
|
El-Gabalawy H. The Impact of Rheumatoid Arthritis on First Nations and How We Can Work With Communities to Prevent It. J Rheumatol 2024; 51:3-9. [PMID: 38950968 DOI: 10.3899/jrheum.2024-0369_dunlop-dottridge] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2024] [Indexed: 07/03/2024]
Abstract
Rheumatoid arthritis (RA) is prevalent in many Indigenous North American First Nations (FN) and tends to be seropositive, familial, and disabling, as well as associated with highly unfavorable outcomes such as early mortality. The risk of developing RA is based on a perfect storm of gene-environment interactions underpinning this risk. The gene-environment interactions include a high frequency of shared epitope encoding HLA alleles, particularly HLA-DRB1*1402, in the background population, and prevalent predisposing environmental factors such as smoking and periodontal disease. Together, these provide a compelling rationale for an RA prevention agenda in FN communities. Our research team has worked in partnership with several FN communities to prospectively follow the first-degree relatives of FN patients with RA, with the aim of better understanding the preclinical stages of RA in this population. We have focused on specific features of the anticitrullinated protein antibodies (ACPA) and other proteomic biomarkers as predictors of future development of RA. These studies have now led us to consider interventions having a favorable risk-benefit ratio if applied at a stage prior to a hypothetical "point of no return," when the autoimmunity potentially becomes irreversible. Based on a supportive mouse model and available human studies of curcumin, omega-3, and vitamin D supplements, we are undertaking studies where we screen communities using dried blood spot technology adapted for the detection of ACPA, and then enrolling ACPA-positive individuals in studies that use a combination of these supplements. These studies are guided by shared decision-making principles.
Collapse
Affiliation(s)
- Hani El-Gabalawy
- H. El-Gabalawy, MD, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
| |
Collapse
|
5
|
Furst A, Gill T. Exploring the role of gut microbes in spondyloarthritis: Implications for pathogenesis and therapeutic strategies. Best Pract Res Clin Rheumatol 2024; 38:101961. [PMID: 38851970 DOI: 10.1016/j.berh.2024.101961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/11/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
The gut microbiota plays a pivotal role in regulating host immunity, and dysregulation of this interaction is implicated in autoimmune and inflammatory diseases, including spondyloarthritis (SpA). This review explores microbial dysbiosis and altered metabolic function observed in various forms of SpA, such as ankylosing spondylitis (AS), psoriatic arthritis (PsA), acute anterior uveitis (AAU), and SpA-associated gut inflammation. Studies on animal models and clinical samples highlight the association between gut microbial dysbiosis, metabolic perturbations and immune dysregulation in SpA pathogenesis. These studies have received impetus through next-generation sequencing methods, which have enabled the characterization of gut microbial composition and function, and host gene expression. Microbial/metabolomic studies have revealed potential biomarkers and therapeutic targets, such as short-chain fatty acids, and tryptophan metabolites, offering insights into disease mechanisms and treatment approaches. Further studies on microbial function and its modulation of the immune response have uncovered molecular mechanisms underlying various SpA. Understanding the complex interplay between microbial community structure and function holds promise for improved diagnosis and management of SpA and other autoimmune disorders.
Collapse
Affiliation(s)
- Alec Furst
- School of Medicine, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Tejpal Gill
- Division of Arthritis and Rheumatic Diseases, Oregon Health and Science University, Portland, OR, 97239, USA.
| |
Collapse
|
6
|
Seymour BJ, Allen BE, Kuhn KA. Microbial Mechanisms of Rheumatoid Arthritis Pathogenesis. Curr Rheumatol Rep 2024; 26:124-132. [PMID: 38300467 PMCID: PMC11141067 DOI: 10.1007/s11926-024-01135-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2024] [Indexed: 02/02/2024]
Abstract
PURPOSE OF REVIEW Host-microbiome interactions have been implicated in the pathophysiology of rheumatoid arthritis (RA), but the data linking specific microbes to RA is largely associative. Here, we review recent studies that have interrogated specific mechanistic links between microbes and host in the setting of RA. RECENT FINDINGS Several candidate bacterial species and antigens that may trigger the conversion of an anti-bacterial to an autoimmune response have been recently identified. Additional studies have identified microbial metabolic pathways that are altered in RA. Some of these microbial species and metabolic pathways have been validated in mouse models to induce RA-like immune responses, providing initial evidence of specific mechanisms by which the microbiota contributes to the development of RA. Several microbial species, antigens, and metabolites have been identified as potential contributors to RA pathophysiology. Further interrogation and validation of these pathways may identify novel biomarkers of or therapeutic avenues for RA.
Collapse
Affiliation(s)
- Brenda J Seymour
- Division of Rheumatology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brendan E Allen
- Division of Rheumatology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kristine A Kuhn
- Division of Rheumatology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| |
Collapse
|
7
|
Ma L, Ge Y, Brown J, Choi SC, Elshikha A, Kanda N, Terrell M, Six N, Garcia A, Mohamadzadeh M, Silverman G, Morel L. Dietary tryptophan and genetic susceptibility expand gut microbiota that promote systemic autoimmune activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.16.575942. [PMID: 38293097 PMCID: PMC10827173 DOI: 10.1101/2024.01.16.575942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Tryptophan modulates disease activity and the composition of microbiota in the B6.Sle1.Sle2.Sle3 (TC) mouse model of lupus. To directly test the effect of tryptophan on the gut microbiome, we transplanted fecal samples from TC and B6 control mice into germ-free or antibiotic-treated non-autoimmune B6 mice that were fed with a high or low tryptophan diet. The recipient mice with TC microbiota and high tryptophan diet had higher levels of immune activation, autoantibody production and intestinal inflammation. A bloom of Ruminococcus gnavus (Rg), a bacterium associated with disease flares in lupus patients, only emerged in the recipients of TC microbiota fed with high tryptophan. Rg depletion in TC mice decreased autoantibody production and increased the frequency of regulatory T cells. Conversely, TC mice colonized with Rg showed higher autoimmune activation. Overall, these results suggest that the interplay of genetic and tryptophan can influence the pathogenesis of lupus through the gut microbiota.
Collapse
Affiliation(s)
- Longhuan Ma
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| | - Yong Ge
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| | - Josephine Brown
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL
| | - Seung-Chul Choi
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| | - Ahmed Elshikha
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL
| | - Nathalie Kanda
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL
| | - Morgan Terrell
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL
| | - Natalie Six
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| | - Abigail Garcia
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| | - Mansour Mohamadzadeh
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| | | | - Laurence Morel
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX
| |
Collapse
|