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Alabarse PG, Oliveira P, Qin H, Yan T, Migaud M, Terkeltaub R, Liu-Bryan R. The NADase CD38 is a central regulator in gouty inflammation and a novel druggable therapeutic target. Inflamm Res 2024:10.1007/s00011-024-01863-y. [PMID: 38493256 DOI: 10.1007/s00011-024-01863-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/23/2024] [Accepted: 02/13/2024] [Indexed: 03/18/2024] Open
Abstract
OBJECTIVES Cellular NAD+ declines in inflammatory states associated with increased activity of the leukocyte-expressed NADase CD38. In this study, we tested the potential role of therapeutically targeting CD38 and NAD+ in gout. METHODS We studied cultured mouse wild type and CD38 knockout (KO) murine bone marrow derived macrophages (BMDMs) stimulated by monosodium urate (MSU) crystals and used the air pouch gouty inflammation model. RESULTS MSU crystals induced CD38 in BMDMs in vitro, associated with NAD+ depletion, and IL-1β and CXCL1 release, effects reversed by pharmacologic CD38 inhibitors (apigenin, 78c). Mouse air pouch inflammatory responses to MSU crystals were blunted by CD38 KO and apigenin. Pharmacologic CD38 inhibition suppressed MSU crystal-induced NLRP3 inflammasome activation and increased anti-inflammatory SIRT3-SOD2 activity in macrophages. BMDM RNA-seq analysis of differentially expressed genes (DEGs) revealed CD38 to control multiple MSU crystal-modulated inflammation pathways. Top DEGs included the circadian rhythm modulator GRP176, and the metalloreductase STEAP4 that mediates iron homeostasis, and promotes oxidative stress and NF-κB activation when it is overexpressed. CONCLUSIONS CD38 and NAD+ depletion are druggable targets controlling the MSU crystal- induced inflammation program. Targeting CD38 and NAD+ are potentially novel selective molecular approaches to limit gouty arthritis.
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Affiliation(s)
- Paulo Gil Alabarse
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
| | - Patricia Oliveira
- University of California San Diego, La Jolla, San Diego, CA, USA
- The Janssen Pharmaceutical Companies of Johnson & Johnson, La Jolla, San Diego, CA, USA
| | - Huaping Qin
- University of California San Diego, La Jolla, San Diego, CA, USA
| | - Tiffany Yan
- University of California San Diego, La Jolla, San Diego, CA, USA
- Gritstone Bio, Emeryville, CA, USA
| | - Marie Migaud
- Department of Pharmacology, F. Whiddon College of Medicine, Mitchell Cancer Institute, University of South Alabama, Mobile, AL, 36604, USA
| | - Robert Terkeltaub
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- University of California San Diego, La Jolla, San Diego, CA, USA
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA.
- University of California San Diego, La Jolla, San Diego, CA, USA.
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Sanchez C, Campeau A, Liu-Bryan R, Mikuls T, O'Dell J, Gonzalez D, Terkeltaub R. Sustained xanthine oxidase inhibitor treat to target urate lowering therapy rewires a tight inflammation serum protein interactome. Res Sq 2024:rs.3.rs-3770277. [PMID: 38260556 PMCID: PMC10802734 DOI: 10.21203/rs.3.rs-3770277/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Background Effective xanthine oxidoreductase inhibition (XOI) urate-lowering treatment (ULT) to target significantly reduces gout flare burden and synovitis between 1-2 years therapy, without clearing all monosodium urate crystal deposits. Paradoxically, treat to target ULT is associated with increased flare activity for at least 1 year in duration on average, before gout flare burden decreases. Since XOI has anti-inflammatory effects, we tested for biomarkers of sustained, effective ULT that alters gouty inflammation. Methods We characterized the proteome of febuxostat-treated murine bone marrow macrophages. Blood samples (baseline and 48 weeks ULT) were analyzed by unbiased proteomics in febuxostat and allopurinol ULT responders from two, independent, racially and ethnically distinct comparative effectiveness trial cohorts (n=19, n=30). STRING-db and multivariate analyses supplemented determinations of significantly altered proteins via Wilcoxon matched pairs signed rank testing. Results The proteome of cultured IL-1b-stimulated macrophages revealed febuxostat-induced anti-inflammatory changes, including for classical and alternative pathway complement activation pathways. At 48 weeks ULT, with altered purine metabolism confirmed by serum metabolomics, serum urate dropped >30%, to normal (<6.8 mg/dL) in all the studied patients. Overall, flares declined from baseline. Treated gout patient sera and peripheral blood mononuclear cells (PBMCs) showed significantly altered proteins (p<0.05) in clustering and proteome networks. CRP was not a useful therapy response biomarker. By comparison, significant serum proteome changes included decreased complement C8 heterotrimer C8A and C8G chains essential for C5b-9 membrane attack complex assembly and function; increase in the NLRP3 inflammasome activation promoter vimentin; increased urate crystal phagocytosis inhibitor sCD44; increased gouty inflammation pro-resolving mediator TGFB1; decreased phagocyte-recruiting chemokine PPBP/CXCL7, and increased monocyte/macrophage-expressed keratin-related proteins (KRT9,14,16) further validated by PBMC proteomics. STRING-db analyses of significantly altered serum proteins from both cohorts revealed a tight interactome network including central mediators of gouty inflammation (eg, IL-1B, CXCL8, IL6, C5). Conclusions Rewiring of inflammation mediators in a tight serum protein interactome was a biomarker of sustained XOI-based ULT that effectively reduced serum urate and gout flares. Monitoring of the serum and PBMC proteome, including for changes in the complement pathway could help determine onset and targets of anti-inflammatory changes in response to effective, sustained XOI-based ULT.Trial Registration: ClinicalTrials.gov Identifier: NCT02579096.
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Gil Alabarse P, Chen LY, Oliveira P, Qin H, Liu-Bryan R. Targeting CD38 to Suppress Osteoarthritis Development and Associated Pain After Joint Injury in Mice. Arthritis Rheumatol 2023; 75:364-374. [PMID: 36103412 PMCID: PMC9998345 DOI: 10.1002/art.42351] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 08/11/2022] [Accepted: 09/08/2022] [Indexed: 01/12/2023]
Abstract
OBJECTIVE This study was undertaken to determine the role of CD38, which can function as an enzyme to degrade NAD+ , in osteoarthritis (OA) development. METHODS Human knee cartilage from normal donors and OA donors were examined for CD38 expression. "Gain-of-function," through overexpression of CD38 via transient transfection, and "loss-of-function," through pharmacologic inhibition of CD38, approaches were used to assess the effects of CD38 on intracellular NAD+ :NADH ratio and catabolic activity in chondrocytes. We also initiated joint injury-induced OA by surgical destabilization of the medial meniscus (DMM) in CD38 knockout mice and wild-type (WT; C57BL/6) mice and in WT male mice in the presence or absence of apigenin treatment. Cartilage degradation, synovial inflammation, subchondral bone changes, and pain behavior were evaluated after DMM surgery. We also examined expression of CD38 and the neuropeptide calcitonin gene-related peptide (CGRP) in knee sections from these mice. RESULTS CD38 expression was up-regulated in human knee OA cartilage and in chondrocytes stimulated with the proinflammatory cytokine interleukin-1β (IL-1β). Overexpression of CD38 in chondrocytes resulted in reduced cellular NAD+ :NADH ratio and augmented catabolic responses to IL-1β. These effects were reversed by pharmacologic inhibition of CD38. Cartilage degradation and synovial inflammation, associated with increased CD38 expression in cartilage and synovium, osteophyte formation and subchondral bone sclerosis, and pain-like behavior linked to increased CGRP expression in the synovium were observed in WT mice after joint injury. Such effects were significantly reduced in mice deficient in CD38 through either genetic knockout or pharmacologic inhibition. CONCLUSION CD38 deficiency exerts OA disease-modifying effects. Inhibition of CD38 has the potential to be a novel therapeutic approach for OA treatment.
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Affiliation(s)
| | - Liang-Yu Chen
- VA San Diego Healthcare System and University of California San Diego
| | - Patricia Oliveira
- VA San Diego Healthcare System and University of California San Diego
| | | | - Ru Liu-Bryan
- VA San Diego Healthcare System and University of California San Diego
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Elsaid K, Merriman TR, Rossitto LA, Liu-Bryan R, Karsh J, Phipps-Green A, Jay GD, Elsayed S, Qadri M, Miner M, Cadzow M, Dambruoso TJ, Schmidt TA, Dalbeth N, Chhana A, Höglund J, Ghassemian M, Campeau A, Maltez N, Karlsson NG, Gonzalez DJ, Terkeltaub R. Amplification of Inflammation by Lubricin Deficiency Implicated in Incident, Erosive Gout Independent of Hyperuricemia. Arthritis Rheumatol 2022; 75:794-805. [PMID: 36457235 DOI: 10.1002/art.42413] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/26/2022] [Accepted: 11/22/2022] [Indexed: 12/04/2022]
Abstract
OBJECTIVE In gout, hyperuricemia promotes urate crystal deposition, which stimulates the NLRP3 inflammasome and interleukin-1β (IL-1β)-mediated arthritis. Incident gout without background hyperuricemia is rarely reported. To identify hyperuricemia-independent mechanisms driving gout incidence and progression, we characterized erosive urate crystalline inflammatory arthritis in a young female patient with normouricemia diagnosed as having sufficient and weighted classification criteria for gout according to the American College of Rheumatology (ACR)/EULAR gout classification criteria (the proband). METHODS We conducted whole-genome sequencing, quantitative proteomics, whole-blood RNA-sequencing analysis using serum samples from the proband. We used a mouse model of IL-1β-induced knee synovitis to characterize proband candidate genes, biomarkers, and pathogenic mechanisms of gout. RESULTS Lubricin level was attenuated in human proband serum and associated with elevated acute-phase reactants and inflammatory whole-blood transcripts and transcriptional pathways. The proband had predicted damaging gene variants of NLRP3 and of inter-α trypsin inhibitor heavy chain 3, an inhibitor of lubricin-degrading cathepsin G. Changes in the proband's serum protein interactome network supported enhanced lubricin degradation, with cathepsin G activity increased relative to its inhibitors, SERPINB6 and thrombospondin 1. Activation of Toll-like receptor 2 (TLR-2) suppressed levels of lubricin mRNA and lubricin release in cultured human synovial fibroblasts (P < 0.01). Lubricin blunted urate crystal precipitation and IL-1β induction of xanthine oxidase and urate in cultured macrophages (P < 0.001). In lubricin-deficient mice, injection of IL-1β in knees increased xanthine oxidase-positive synovial resident M1 macrophages (P < 0.05). CONCLUSION Our findings linked normouricemic erosive gout to attenuated lubricin, with impaired control of cathepsin G activity, compounded by deleterious NLRP3 variants. Lubricin suppressed monosodium urate crystallization and blunted IL-1β-induced increases in xanthine oxidase and urate in macrophages. The collective activities of articular lubricin that could limit incident and erosive gouty arthritis independently of hyperuricemia are subject to disruption by inflammation, activated cathepsin G, and synovial fibroblast TLR-2 signaling.
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Affiliation(s)
- Khaled Elsaid
- Chapman University School of Pharmacy, Irvine, California
| | - Tony R Merriman
- Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, and Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Leigh-Ana Rossitto
- Department of Pharmacology, School of Medicine, and Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, California
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, San Diego, and Department of Medicine, UC San Diego, La Jolla, California
| | - Jacob Karsh
- The Ottawa Hospital, Division of Rheumatology, University of Ottawa, Canada
| | | | - Gregory D Jay
- Department of Emergency Medicine, Alpert School of Medicine, and Division of Biomedical Engineering, School of Engineering, Brown University, Rhode, Island
| | - Sandy Elsayed
- Chapman University School of Pharmacy, Irvine, California
| | | | - Marin Miner
- VA San Diego Healthcare System, San Diego, California
| | - Murray Cadzow
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Talia J Dambruoso
- Division of Biomedical Engineering, School of Engineering, Brown University, Rhode, Island
| | - Tannin A Schmidt
- Biomedical Engineering Department, School of Dental Medicine, UConn Health, Farmington, Connecticut
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Ashika Chhana
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Jennifer Höglund
- Department of Medical Biochemistry, Institute for Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Majid Ghassemian
- Biomolecular and Proteomics Mass Spectrometry Facility, Department of Chemistry/Biochemistry, UC San Diego
| | - Anaamika Campeau
- Department of Pharmacology, School of Medicine, and Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, California
| | - Nancy Maltez
- The Ottawa Hospital, Division of Rheumatology, University of Ottawa, Canada
| | - Niclas G Karlsson
- Faculty of Health Sciences, Oslo Metropolitan University, Oslo, Norway, and Department of Medical Biochemistry, Institute for Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - David J Gonzalez
- Department of Pharmacology, School of Medicine, and Skaggs School of Pharmacy and Pharmaceutical Sciences, Collaborative Center for Multiplexed Proteomics, Program for Integrative Omics and Data Science in Disease Prevention and Therapeutics, UC San Diego, La Jolla, California
| | - Robert Terkeltaub
- VA San Diego Healthcare System and Department of Medicine, UC San Diego
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Hilsabeck TAU, Liu-Bryan R, Guo T, Wilson KA, Bose N, Raftery D, Beck JN, Lang S, Jin K, Nelson CS, Oron T, Stoller M, Promislow D, Brem RB, Terkeltaub R, Kapahi P. A fly GWAS for purine metabolites identifies human FAM214 homolog medusa, which acts in a conserved manner to enhance hyperuricemia-driven pathologies by modulating purine metabolism and the inflammatory response. GeroScience 2022; 44:2195-2211. [PMID: 35381951 PMCID: PMC9616999 DOI: 10.1007/s11357-022-00557-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 03/25/2022] [Indexed: 01/14/2023] Open
Abstract
Elevated serum urate (hyperuricemia) promotes crystalline monosodium urate tissue deposits and gout, with associated inflammation and increased mortality. To identify modifiers of uric acid pathologies, we performed a fly Genome-Wide Association Study (GWAS) on purine metabolites using the Drosophila Genetic Reference Panel strains. We tested the candidate genes using the Drosophila melanogaster model of hyperuricemia and uric acid crystallization ("concretion formation") in the kidney-like Malpighian tubule. Medusa (mda) activity increased urate levels and inflammatory response programming. Conversely, whole-body mda knockdown decreased purine synthesis precursor phosphoribosyl pyrophosphate, uric acid, and guanosine levels; limited formation of aggregated uric acid concretions; and was sufficient to rescue lifespan reduction in the fly hyperuricemia and gout model. Levels of mda homolog FAM214A were elevated in inflammatory M1- and reduced in anti-inflammatory M2-differentiated mouse bone marrow macrophages, and influenced intracellular uric acid levels in human HepG2 transformed hepatocytes. In conclusion, mda/FAM214A acts in a conserved manner to regulate purine metabolism, promotes disease driven by hyperuricemia and associated tissue inflammation, and provides a potential novel target for uric acid-driven pathologies.
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Affiliation(s)
- Tyler A U Hilsabeck
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
- Davis School of Gerontology, University of Southern California, University Park, Los Angeles, CA, 90007, USA
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Medicine, Division of Rheumatology, Allergy and Immunology, University of California San Diego, San Diego, CA, 92093, USA
| | - Tracy Guo
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Medicine, Division of Rheumatology, Allergy and Immunology, University of California San Diego, San Diego, CA, 92093, USA
| | - Kenneth A Wilson
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
| | - Neelanjan Bose
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
| | - Daniel Raftery
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA
| | - Jennifer N Beck
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Room A-632, San Francisco, CA, 94143, USA
| | - Sven Lang
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany
| | - Kelly Jin
- Allen Institute for Brain Science, Seattle, WA, 98109, USA
- Department of Pathology, University of Washington, Seattle, WA, 98195, USA
| | - Christopher S Nelson
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
| | - Tal Oron
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
| | - Marshall Stoller
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Room A-632, San Francisco, CA, 94143, USA
| | - Daniel Promislow
- Department of Pathology, University of Washington, Seattle, WA, 98195, USA
- Department of Biology, University of Washington, Seattle, WA, 98195, USA
| | - Rachel B Brem
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA
- Davis School of Gerontology, University of Southern California, University Park, Los Angeles, CA, 90007, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, 111 Koshland Hall, Berkeley, CA, 94720, USA
| | - Robert Terkeltaub
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Medicine, Division of Rheumatology, Allergy and Immunology, University of California San Diego, San Diego, CA, 92093, USA
| | - Pankaj Kapahi
- Buck Institute for Research On Aging, 8001 Redwood Blvd., Novato, CA, 94945, USA.
- Davis School of Gerontology, University of Southern California, University Park, Los Angeles, CA, 90007, USA.
- Department of Urology, University of California, San Francisco, 400 Parnassus Avenue, Room A-632, San Francisco, CA, 94143, USA.
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Li J, Wang Y, Chen D, Liu-Bryan R. Oral administration of berberine limits post-traumatic osteoarthritis development and associated pain via AMP-activated protein kinase (AMPK) in mice. Osteoarthritis Cartilage 2022; 30:160-171. [PMID: 34687898 PMCID: PMC8712393 DOI: 10.1016/j.joca.2021.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [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: 06/14/2021] [Revised: 09/30/2021] [Accepted: 10/18/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE We investigated the effect of berberine, a natural plant product that can activate AMP-activated protein kinase (AMPK), on Osteoarthritis (OA) development and associated pain in mice. DESIGN Human primary knee chondrocytes were utilized to investigate how AMPK is activated by berberine. Both global knockout (KO) of AMPKα1 and congenic wild type (WT) mice were subjected to the post-traumatic OA through destabilization of medial meniscus (DMM) surgery. Two weeks after surgery, the mice were randomly divided into two groups with one group receiving berberine chloride daily via drinking water and were sacrificed at 6 and 12 weeks after surgery. OA severity was assessed by histological and histomorphometric analyses of cartilage degradation, synovitis, and osteophyte formation. OA-associated pain behavior was also determined. Immunohistochemistry (IHC) analyses were carried out to examine changes in AMPK signaling. RESULTS Berberine induced phosphorylation of AMPKα (Thr172) via liver kinase B1 (LKB1), the major upstream kinase of AMPK, in chondrocytes in vitro. Both WT and AMPKα1KO developed OA and associated pain post DMM surgery. However, treatment with berberine significantly reduced severity of OA and associated pain in WT but not AMPKα1KO mice. IHC analysis of WT DMM knee cartilage further revealed that berberine inhibited concomitant loss of expression and phosphorylation of AMPKα and expression of SIRT1 and SIRT3, suggesting an important role of activation of AMPK signaling in mediating beneficial effect of berberine. CONCLUSIONS Berberine acts through AMPK to reduce joint structural damage and pain associated with post-traumatic OA in mice in vivo.
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Affiliation(s)
- Jun Li
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Yun Wang
- Department of Medicine, University of California San Diego, La Jolla, USA.,Present address: Valo Health, Lexington, MA, USA
| | - Di Chen
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.,Present address: Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, San Diego, USA.,Department of Medicine, University of California San Diego, La Jolla, USA.,Correspondence to: Ru Liu-Bryan, VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA 92161. Telephone: 858 552 8585. Fax: 858 552 7425. , or Di Chen, Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China. Telephone: 86-0755-8658-5255. Fax: 86-0755-8639-2299.
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Guma M, Dadpey B, Coras R, Mikuls TR, Hamilton B, Quehenberger O, Thorisdottir H, Bittleman D, Lauro K, Reilly SM, Liu-Bryan R, Terkeltaub R. Xanthine oxidase inhibitor urate-lowering therapy titration to target decreases serum free fatty acids in gout and suppresses lipolysis by adipocytes. Arthritis Res Ther 2022; 24:175. [PMID: 35879786 PMCID: PMC9310412 DOI: 10.1186/s13075-022-02852-4] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 06/26/2022] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE Linked metabolic and cardiovascular comorbidities are prevalent in hyperuricemia and gout. For mechanistic insight into impact on inflammatory processes and cardiometabolic risk factors of xanthine oxidase inhibitor urate-lowering therapy (ULT) titration to target, we performed a prospective study of gout serum metabolomes from a ULT trial. METHODS Sera of gout patients meeting the 2015 ACR/EULAR gout classification criteria (n = 20) and with hyperuricemia were studied at time zero and weeks 12 and 24 of febuxostat or allopurinol dose titration ULT. Ultrahigh performance liquid chromatography-tandem mass spectroscopy acquired the serum spectra. Data were assessed using the Metabolon and Metaboloanalyst software. Lipolysis validation assays were done in febuxostat and/or colchicine-treated 3T3-L1 differentiated adipocytes. RESULTS Serum urate decreased from time zero (8.21 ±1.139 SD) at weeks 12 (5.965 ± 1.734 SD) and 24 (5.655 ±1.763 SD). Top metabolites generated by changes in nucleotide and certain amino acid metabolism and polyamine pathways were enriched at 12 and 24 weeks ULT, respectively. Decreases in multiple fatty acid metabolites were observed at 24 weeks, linked with obesity. In cultured adipocytes, febuxostat significantly decreased while colchicine increased the lipolytic response to β-adrenergic-agonism or TNF. CONCLUSION Metabolomic profiles linked xanthine oxidase inhibitor-based ULT titration to target with reduced serum free fatty acids. In vitro validation studies revealed that febuxostat, but not colchicine, reduced lipolysis in cultured adipocytes. Since soluble urate, xanthine oxidase inhibitor treatment, and free fatty acids modulate inflammation, our findings suggest that by suppressing lipolysis, ULT could regulate inflammation in gout and comorbid metabolic and cardiovascular disease.
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Affiliation(s)
- Monica Guma
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA ,grid.7080.f0000 0001 2296 0625Department of Medicine, Autonomous University of Barcelona, Plaça Cívica, 08193 Bellaterra, Barcelona Spain
| | - Benyamin Dadpey
- grid.217200.60000 0004 0627 2787Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093 USA
| | - Roxana Coras
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA ,grid.7080.f0000 0001 2296 0625Department of Medicine, Autonomous University of Barcelona, Plaça Cívica, 08193 Bellaterra, Barcelona Spain
| | - Ted R. Mikuls
- grid.266813.80000 0001 0666 4105University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - Bartlett Hamilton
- grid.266813.80000 0001 0666 4105University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - Oswald Quehenberger
- grid.217200.60000 0004 0627 2787Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093 USA
| | - Hilda Thorisdottir
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - David Bittleman
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - Kimberly Lauro
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - Shannon M. Reilly
- grid.217200.60000 0004 0627 2787Division of Metabolism and Endocrinology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093 USA ,grid.5386.8000000041936877XWeill Center for Metabolic Health, Department of Medicine, Weill Cornell Medicine, New York, NY 10021 USA
| | - Ru Liu-Bryan
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
| | - Robert Terkeltaub
- grid.266100.30000 0001 2107 4242Department of Medicine, UC San Diego, San Diego VA Healthcare Service, 3350 La Jolla Village Drive, San Diego, CA 92161 USA
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Abstract
Chondrocytes, the only cells in articular cartilage, are metabolically active and responsible for the turnover of extracellular matrix and maintenance of the tissue homeostasis. Changes in chondrocyte function can cause degradation of the matrix and loss of articular cartilage integrity, leading to development and progression of osteoarthritis (OA). These changes are exemplified by accumulated mitochondrial damage and dysfunction. Because mitochondria are the critical organelles to produce energy and play a key role in cellular processes, the approaches to assess mitochondrial function under both physiological and pathological conditions enable us to uncover the mechanisms on how dysfunction of mitochondria in chondrocytes mediates signaling pathways that are involved in disturbance of cartilage homeostasis. In this chapter, we describe the methods to evaluate mitochondrial biogenesis, activity and mitochondrial DNA (mtDNA) integrity in chondrocytes.
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Affiliation(s)
- Yun Wang
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | | | - Ru Liu-Bryan
- VA San Diego Healthcare System, San Diego, CA, USA. .,Department of Medicine, University of California San Diego, La Jolla, CA, USA.
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Wang Z, Zhao Y, Phipps-Green A, Liu-Bryan R, Ceponis A, Boyle DL, Wang J, Merriman TR, Wang W, Terkeltaub R. Differential DNA Methylation of Networked Signaling, Transcriptional, Innate and Adaptive Immunity, and Osteoclastogenesis Genes and Pathways in Gout. Arthritis Rheumatol 2020; 72:802-814. [PMID: 31738005 DOI: 10.1002/art.41173] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE In gout, autoinflammatory responses to urate crystals promote acute arthritis flares, but the pathogeneses of tophi, chronic synovitis, and erosion are less well understood. Defining the pathways of epigenomic immunity training can reveal novel pathogenetic factors and biomarkers. The present study was undertaken to seminally probe differential DNA methylation patterns utilizing epigenome-wide analyses in patients with gout. METHODS Peripheral blood mononuclear cells (PBMCs) were obtained from a San Diego cohort of patients with gout (n = 16) and individually matched healthy controls (n = 14). PBMC methylome data were processed with ChAMP package in R. ENCODE data and Taiji data analysis software were used to analyze transcription factor (TF)-gene networks. As an independent validation cohort, whole blood DNA samples from New Zealand Māori subjects (n = 13 patients with gout, n = 16 control subjects without gout) were analyzed. RESULTS Differentially methylated loci clearly separated gout patients from controls, as determined by hierarchical clustering and principal components analyses. IL23R, which mediates granuloma formation and cell invasion, was identified as one of the multiple differentially methylated gout risk genes. Epigenome-wide analyses revealed differential methylome pathway enrichment for B and T cell receptor signaling, Th17 cell differentiation and interleukin-17 signaling, convergent longevity regulation, circadian entrainment, and AMP-activated protein kinase signaling, which are pathways that impact inflammation via insulin-like growth factor 1 receptor, phosphatidylinositol 3-kinase/Akt, NF-κB, mechanistic target of rapamycin signaling, and autophagy. The gout cohorts overlapped for 37 (52.9%) of the 70 TFs with hypomethylated sequence enrichment and for 30 (78.9%) of the 38 enriched KEGG pathways identified via TFs. Evidence of shared differentially methylated gout TF-gene networks, including the NF-κB activation-limiting TFs MEF2C and NFATC2, pointed to osteoclast differentiation as the most strongly weighted differentially methylated pathway that overlapped in both gout cohorts. CONCLUSION These findings of differential DNA methylation of networked signaling, transcriptional, innate and adaptive immunity, and osteoclastogenesis genes and pathways suggest that they could serve as novel therapeutic targets in the management of flares, tophi, chronic synovitis, and bone erosion in patients with gout.
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Affiliation(s)
| | | | | | - Ru Liu-Bryan
- University of California, San Diego and San Diego VAMC
| | | | | | - Jun Wang
- University of California, San Diego
| | | | - Wei Wang
- University of California, San Diego
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10
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Li J, Zhang B, Liu WX, Lu K, Pan H, Wang T, Oh CD, Yi D, Huang J, Zhao L, Ning G, Xing C, Xiao G, Liu-Bryan R, Feng S, Chen D. Metformin limits osteoarthritis development and progression through activation of AMPK signalling. Ann Rheum Dis 2020; 79:635-645. [PMID: 32156705 PMCID: PMC7213329 DOI: 10.1136/annrheumdis-2019-216713] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 01/03/2023]
Abstract
Objectives In this study, we aim to determine the effect of metformin on osteoarthritis (OA) development and progression. Methods Destabilisation of the medial meniscus (DMM) surgery was performed in 10-week-old wild type and AMP-activated protein kinase (AMPK)α1 knockout (KO) mice. Metformin (4 mg/day in drinking water) was given, commencing either 2 weeks before or 2 weeks after DMM surgery. Mice were sacrificed 6 and 12 weeks after DMM surgery. OA phenotype was analysed by micro-computerised tomography (μCT), histology and pain-related behaviour tests. AMPKα1 (catalytic alpha subunit of AMPK) expression was examined by immunohistochemistry and immunofluorescence analyses. The OA phenotype was also determined by μCT and MRI in non-human primates. Results Metformin upregulated phosphorylated and total AMPK expression in articular cartilage tissue. Mild and more severe cartilage degeneration was observed at 6 and 12 weeks after DMM surgery, evidenced by markedly increased Osteoarthritis Research Society International scores, as well as reduced cartilage areas. The administration of metformin, commencing either before or after DMM surgery, caused significant reduction in cartilage degradation. Prominent synovial hyperplasia and osteophyte formation were observed at both 6 and 12 weeks after DMM surgery; these were significantly inhibited by treatment with metformin either before or after DMM surgery. The protective effects of metformin on OA development were not observed in AMPKα1 KO mice, suggesting that the chondroprotective effect of metformin is mediated by AMPK signalling. In addition, we demonstrated that treatment with metformin could also protect from OA progression in a partial medial meniscectomy animal model in non-human primates. Conclusions The present study suggests that metformin, administered shortly after joint injury, can limit OA development and progression in injury-induced OA animal models.
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Affiliation(s)
- Jun Li
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Bin Zhang
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Wei-Xiao Liu
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Ke Lu
- Research Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Haobo Pan
- Research Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Tingyu Wang
- Department of Pharmacy, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chun-do Oh
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Dan Yi
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Jian Huang
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Lan Zhao
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Guangzhi Ning
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Cong Xing
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Guozhi Xiao
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Ru Liu-Bryan
- Division of Rheumatology, Allergy and Immunology, San Diego VA Healthcare System, San Diego, California, USA
| | - Shiqing Feng
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Di Chen
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, USA .,Research Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Sanchez-Lopez E, Zhong Z, Stubelius A, Sweeney SR, Booshehri LM, Antonucci L, Liu-Bryan R, Lodi A, Terkeltaub R, Lacal JC, Murphy AN, Hoffman HM, Tiziani S, Guma M, Karin M. Choline Uptake and Metabolism Modulate Macrophage IL-1β and IL-18 Production. Cell Metab 2019; 29:1350-1362.e7. [PMID: 30982734 PMCID: PMC6675591 DOI: 10.1016/j.cmet.2019.03.011] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 01/16/2019] [Accepted: 03/19/2019] [Indexed: 02/07/2023]
Abstract
Choline is a vitamin-like nutrient that is taken up via specific transporters and metabolized by choline kinase, which converts it to phosphocholine needed for de novo synthesis of phosphatidylcholine (PC), the main phospholipid of cellular membranes. We found that Toll-like receptor (TLR) activation enhances choline uptake by macrophages and microglia through induction of the choline transporter CTL1. Inhibition of CTL1 expression or choline phosphorylation attenuated NLRP3 inflammasome activation and IL-1β and IL-18 production in stimulated macrophages. Mechanistically, reduced choline uptake altered mitochondrial lipid profile, attenuated mitochondrial ATP synthesis, and activated the energy sensor AMP-activated protein kinase (AMPK). By potentiating mitochondrial recruitment of DRP1, AMPK stimulates mitophagy, which contributes to termination of NLRP3 inflammasome activation. Correspondingly, choline kinase inhibitors ameliorated acute and chronic models of IL-1β-dependent inflammation.
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Affiliation(s)
- Elsa Sanchez-Lopez
- Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, 92037, USA
| | - Zhenyu Zhong
- Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, 92037, USA; Department of Immunology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas TX 75390, USA
| | - Alexandra Stubelius
- Division of Rheumatology, Allergy and Immunology, University of California San Diego, La Jolla, CA, 92037, USA
| | - Shannon R Sweeney
- Department of Nutritional Sciences, The University of Texas at Austin, Austin, TX, 78723-3092, USA
| | - Laela M Booshehri
- Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, 92037, USA
| | - Laura Antonucci
- Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, 92037, USA
| | - Ru Liu-Bryan
- Division of Rheumatology, Allergy and Immunology, University of California San Diego, La Jolla, CA, 92037, USA; VA San Diego Healthcare System, University of California San Diego, La Jolla, CA, 92037, USA
| | - Alessia Lodi
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78723-3092, USA; Department of Nutritional Sciences, The University of Texas at Austin, Austin, TX, 78723-3092, USA
| | - Robert Terkeltaub
- Division of Rheumatology, Allergy and Immunology, University of California San Diego, La Jolla, CA, 92037, USA; VA San Diego Healthcare System, University of California San Diego, La Jolla, CA, 92037, USA
| | - Juan Carlos Lacal
- Translational Oncology, Department of Oncology, Hospital Universitario Fuenlabrada, Instituto de Investigación Sanitaria IdiPAZ, Madrid, Spain
| | - Anne N Murphy
- Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, 92037, USA
| | - Hal M Hoffman
- Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, 92037, USA
| | - Stefano Tiziani
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78723-3092, USA; Department of Nutritional Sciences, The University of Texas at Austin, Austin, TX, 78723-3092, USA; Department of Pediatrics, Dell Medical School, The University of Texas at Austin, Austin, TX, 78723-3092, USA
| | - Monica Guma
- Division of Rheumatology, Allergy and Immunology, University of California San Diego, La Jolla, CA, 92037, USA
| | - Michael Karin
- Departments of Pharmacology and Pathology, University of California San Diego, La Jolla, CA, 92037, USA.
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Sanchez-Lopez E, Zhong Z, Stubelius A, Sweeney SR, Booshehri L, Antonucci L, Liu-Bryan R, Lodi A, Terkeltaub R, Lacal JC, Murphy AN, Hoffman HM, Tiziani S, Guma M, Karin M. Choline uptake and metabolism modulate macrophage immunity. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.125.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Choline is a vitamin-like nutrient that is taken up via specific transporters and metabolized by choline kinase (ChoKα) which converts it to phosphocholine needed for de novo synthesis of phosphatidylcholine (PC), the main phospholipid of cellular membranes. We found that Toll-like receptor (TLR) activation enhances choline uptake by macrophages through induction of the choline transporter CTL1. Choline is rapidly phosphorylated and mobilized to the Kennedy pathway leading to increased cellular phosphatidylcholine production. Inhibition of choline uptake or phosphorylation attenuated NLRP3 inflammasome activation and IL-1β and IL-18 production in stimulated macrophages. Mechanistically, reduced choline uptake altered mitochondrial lipid profile, attenuated mitochondrial ATP synthesis and activated the energy sensor AMP-activated protein kinase (AMPK). By potentiating mitochondrial recruitment of DRP1, AMPK stimulates mitophagy, which contributes to termination of NLRP3 inflammasome activation. Correspondingly, pharmacological ChoKα inhibition ameliorated acute and chronic macrophage-dependent inflammation in vivo.
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Affiliation(s)
- Elsa Sanchez-Lopez
- 1Department of Pharmacology, School of Medicine, University of California San Diego
| | | | | | | | - Laela Booshehri
- 5Department of Pediatrics, University of California San Diego
| | - Laura Antonucci
- 1Department of Pharmacology, School of Medicine, University of California San Diego
| | - Ru Liu-Bryan
- 3Division of Rheumatology, University of California San Diego
- 6VA San Diego Healthcare System
| | - Alessia Lodi
- 7Department of Nutricional Science, University of Texas at Austin
| | - Robert Terkeltaub
- 3Division of Rheumatology, University of California San Diego
- 6VA San Diego Healthcare System
| | | | - Anne N. Murphy
- 1Department of Pharmacology, School of Medicine, University of California San Diego
| | - Hal M Hoffman
- 5Department of Pediatrics, University of California San Diego
| | - Stefano Tiziani
- 7Department of Nutricional Science, University of Texas at Austin
| | - Monica Guma
- 3Division of Rheumatology, University of California San Diego
| | - Michael Karin
- 1Department of Pharmacology, School of Medicine, University of California San Diego
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Berenbaum F, Griffin TM, Liu-Bryan R. Review: Metabolic Regulation of Inflammation in Osteoarthritis. Arthritis Rheumatol 2019; 69:9-21. [PMID: 27564539 DOI: 10.1002/art.39842] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/09/2016] [Indexed: 01/15/2023]
Affiliation(s)
- Francis Berenbaum
- Sorbonnes Universités, UPMC University Paris 06, INSERM, AP-HP Hôpital Saint-Antoine, Centre de Recherche Saint-Antoine, DHU i2B, Paris, France
| | - Timothy M Griffin
- Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City
| | - Ru Liu-Bryan
- VA San Diego Healthcare System and University of California, San Diego
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14
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Chen LY, Wang Y, Terkeltaub R, Liu-Bryan R. Activation of AMPK-SIRT3 signaling is chondroprotective by preserving mitochondrial DNA integrity and function. Osteoarthritis Cartilage 2018; 26:1539-1550. [PMID: 30031925 PMCID: PMC6202232 DOI: 10.1016/j.joca.2018.07.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [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: 01/21/2018] [Revised: 06/11/2018] [Accepted: 07/02/2018] [Indexed: 02/02/2023]
Abstract
OBJECTIVE In osteoarthritis (OA), articular chondrocytes manifest mitochondrial damage, including mitochondrial DNA 4977-bp (mtDNA4977) deletion that impairs mitochondrial function. OA chondrocytes have decreased activity of AMPK, an energy biosensor that promotes mitochondrial biogenesis. Here, we tested if pharmacologic AMPK activation, via downstream activation of predominately mitochondrially localized sirtuin 3 (SIRT3), reverses existing decreases in mitochondrial DNA (mtDNA) integrity and function in human OA chondrocytes and limits mouse knee OA development. DESIGN We assessed mtDNA integrity and function including the common mtDNA4977 deletion and mtDNA content, mitochondrial reactive oxygen species (mtROS) generation, oxygen consumption and intracellular ATP levels. Phosphorylation of AMPKα, expression and activity of SIRT3, acetylation and expression of the mitochondrial antioxidant enzyme SOD2 and DNA repair enzyme 8-oxoguanine glycosylase (OGG1), and expression of subunits of mitochondrial respiratory complexes were examined. We assessed effect of pharmacologic activation of AMPK on age-related spontaneous mouse knee OA. RESULTS The mtDNA4977 deletion was detected in both OA chondrocytes and menadione-treated normal chondrocytes, associated with increased mtROS, decreased SIRT3, and increased acetylation of SOD2 and OGG1. AMPKα1 deficient chondrocytes exhibited significantly reduced SIRT3 activity. AMPK pharmacologic activation attenuated existing mtDNA4977 deletion and improved mitochondrial functions in OA chondrocytes via SIRT3 by reducing acetylation and increasing expression of SOD2 and OGG1, and limited aging-associated mouse knee OA development and progression. CONCLUSIONS AMPK activation, via SIRT3, limits oxidative stress and improves mtDNA integrity and function in OA chondrocytes. These effects likely contribute to chondroprotective effects of AMPK activity.
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Affiliation(s)
| | | | - Robert Terkeltaub
- VA San Diego Healthcare System, San Diego, CA,Dept. of Medicine, UC San Diego
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, San Diego, CA,Dept. of Medicine, UC San Diego,To Whom Correspondence should be addressed: Ru Liu-Bryan PhD, VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA 92161. Telephone: 858 552 8585. Fax: 858 552 7425,
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15
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McWherter C, Choi YJ, Serrano RL, Mahata SK, Terkeltaub R, Liu-Bryan R. Arhalofenate acid inhibits monosodium urate crystal-induced inflammatory responses through activation of AMP-activated protein kinase (AMPK) signaling. Arthritis Res Ther 2018; 20:204. [PMID: 30189890 PMCID: PMC6127987 DOI: 10.1186/s13075-018-1699-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/14/2018] [Indexed: 12/23/2022] Open
Abstract
Background Arhalofenate acid, the active acid form of arhalofenate, is a non-agonist peroxisome proliferator-activated receptor γ (PPARγ) ligand, with uricosuric activity via URAT1 inhibition. Phase II studies revealed decreased acute arthritis flares in arhalofenate-treated gout compared with allopurinol alone. Hence, we investigated the anti-inflammatory effects and mechanisms of arhalofenate and its active acid form for responses to monosodium urate (MSU) crystals. Methods We assessed in-vivo responses to MSU crystals in murine subcutaneous air pouches and in-vitro responses in murine bone marrow-derived macrophages (BMDMs) by enzyme-linked immunosorbent assay (ELISA), SDS-PAGE/Western blot, immunostaining, and transmission electron microscopy analyses. Results Oral administration of arhalofenate (250 mg/kg) blunted total leukocyte ingress, neutrophil influx, and air pouch fluid interleukin (IL)-1β, IL-6, and CXCL1 in response to MSU crystal injection (p < 0.05 for each). Arhalofenate acid (100 μM) attenuated MSU crystal-induced IL-1β production in BMDMs via inhibition of NLRP3 inflammasome activation. In addition, arhalofenate acid dose-dependently increased activation (as assessed by phosphorylation) of AMP-activated protein kinase (AMPK). Studying AMPKα1 knockout mice, we elucidated that AMPK mediated the anti-inflammatory effects of arhalofenate acid. Moreover, arhalofenate acid attenuated the capacity of MSU crystals to suppress AMPK activity, regulated expression of multiple downstream AMPK targets that modulate mitochondrial function and oxidative stress, preserved intact mitochondrial cristae and volume density, and promoted anti-inflammatory autophagy flux in BMDMs. Conclusions Arhalofenate acid is anti-inflammatory and acts via AMPK activation and its downstream signaling in macrophages. These effects likely contribute to a reduction of gout flares. Electronic supplementary material The online version of this article (10.1186/s13075-018-1699-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | - Ramon L Serrano
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA.,University of California San Diego, La Jolla, California, USA
| | - Sushil K Mahata
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA.,University of California San Diego, La Jolla, California, USA
| | - Robert Terkeltaub
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA.,University of California San Diego, La Jolla, California, USA
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA. .,University of California San Diego, La Jolla, California, USA.
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16
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Chen LY, Lotz M, Terkeltaub R, Liu-Bryan R. Modulation of matrix metabolism by ATP-citrate lyase in articular chondrocytes. J Biol Chem 2018; 293:12259-12270. [PMID: 29929979 DOI: 10.1074/jbc.ra118.002261] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 06/04/2018] [Indexed: 02/04/2023] Open
Abstract
Certain dysregulated chondrocyte metabolic adaptive responses such as decreased activity of the master regulator of energy metabolism AMP-activated protein kinase (AMPK) promote osteoarthritis (OA). Metabolism intersects with epigenetic and transcriptional responses. Hence, we studied chondrocyte ATP-citrate lyase (ACLY), which generates acetyl-CoA from mitochondrial-derived citrate, and modulates acetylation of histones and transcription factors. We assessed ACLY in normal and OA human knee chondrocytes and cartilages by Western blotting and immunohistochemistry, and quantified acetyl-CoA fluorometrically. We examined histone and transcription factor lysine acetylation by Western blotting, and assessed histone H3K9 and H3K27 occupancy of iNOS, MMP3, and MMP13 promoters by chromatin immunoprecipitation (ChIP) and quantitative PCR (qPCR). We analyzed iNOS, MMP3, MMP13, aggrecan (ACAN), and Col2a1 gene expression by RT-qPCR. Glucose availability regulated ACLY expression and function, nucleocytosolic acetyl-CoA, and histone acetylation. Human knee OA chondrocytes exhibited increased ACLY activation (assessed by Ser-455 phosphorylation), associated with increased H3K9 and H3K27 acetylation. Inhibition of ACLY attenuated IL-1β-induced transcription of iNOS, MMP3, and MMP13 by suppressing acetylation of p65 NF-κB, H3K9, and H3K27, blunted release of NO, MMP3, and MMP13, and also reduced SOX9 acetylation that promoted SOX9 nuclear translocation, leading to increased aggrecan and Col2a1 mRNA expression. ACLY is a novel player involved in regulation of cartilage matrix metabolism. Increased ACLY activity in OA chondrocytes increased nucleocytosolic acetyl-CoA, leading to increased matrix catabolism via dysregulated histone and transcription factor acetylation. Pharmacologic ACLY inhibition in OA chondrocytes globally reverses these changes and stimulates matrix gene expression and AMPK activation, supporting translational investigation in OA.
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Affiliation(s)
- Liang-Yu Chen
- Veterans Affairs San Diego Healthcare System, San Diego, California 92161
| | - Martin Lotz
- The Scripps Research Institute, La Jolla, California 92037
| | - Robert Terkeltaub
- Veterans Affairs San Diego Healthcare System, San Diego, California 92161; Department of Medicine, University of California San Diego, La Jolla, California 92037
| | - Ru Liu-Bryan
- Veterans Affairs San Diego Healthcare System, San Diego, California 92161; Department of Medicine, University of California San Diego, La Jolla, California 92037.
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Serrano RL, Chen LY, Lotz MK, Liu-Bryan R, Terkeltaub R. Impaired Proteasomal Function in Human Osteoarthritic Chondrocytes Can Contribute to Decreased Levels of SOX9 and Aggrecan. Arthritis Rheumatol 2018; 70:1030-1041. [PMID: 29457374 DOI: 10.1002/art.40456] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 02/13/2018] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Osteoarthritis (OA) chondrocytes exhibit impairment of autophagy, one arm of the proteostasis network that coordinates proteome and organelle quality control and degradation. Deficient proteostasis impacts differentiation and viability, and inflammatory processes in aging and disease. The present study was undertaken to assess ubiquitin proteasome system proteasomal function in OA chondrocytes. METHODS We evaluated human knee cartilage by immunohistochemistry, and assessed proteasomal function, levels of proteasomal core subunits and chaperones, and autophagy in cultured chondrocytes. Assays included Western blotting, quantitative reverse transcription-polymerase chain reaction, proteasomal protease activity assessment, and cell immunofluorescence analysis. RESULTS Human knee OA cartilage exhibited polyubiquitin accumulation, with increased ubiquitin K48-linked polyubiquitinated proteins in situ, suggesting proteasomal impairment. Cultured OA chondrocytes demonstrated accumulation of K48 polyubiquitinated proteins, significantly reduced 20S proteasome core protease activity, and decreased levels of phosphorylated FOXO4 and proteasome 26S subunit, non-ATPase 11 (PSMD11), a FOXO4-inducible promoter of proteasomal activation. Levels of proteasome subunit β type 3 (PSMB3), PSMB5, PSMB6, and proteasome assembly chaperone 1 were not decreased in OA chondrocytes. In normal chondrocytes, PSMD11 small interfering RNA knockdown stimulated certain autophagy machinery elements, increased extracellular nitric oxide (NO) levels, and reduced chondrocytic master transcription factor SOX9 protein and messenger RNA (mRNA) and aggrecan (AGC1) mRNA. PSMD11 gain-of- function by transfection increased proteasomal function, increased levels of SOX9-induced AGC1 mRNA, stimulated elements of the autophagic machinery, and inhibited extracellular levels of interleukin-1-induced NO and matrix metalloproteinase 13 in OA chondrocytes. CONCLUSION Deficient PSMD11, associated with reduced phosphorylated FOXO4, promotes impaired proteasomal function in OA chondrocytes, dysregulation of chondrocytic homeostasis, and decreased levels of SOX9 mRNA, SOX9 protein, and AGC1 mRNA. Chondrocyte proteasomal impairment may be a therapeutic target for OA.
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Affiliation(s)
- Ramon L Serrano
- VA San Diego Healthcare System, University of California San Diego, La Jolla, California
| | - Liang-Yu Chen
- VA San Diego Healthcare System, University of California San Diego, La Jolla, California
| | - Martin K Lotz
- The Scripps Research Institute, La Jolla, California
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, University of California San Diego, La Jolla, California
| | - Robert Terkeltaub
- VA San Diego Healthcare System, University of California San Diego, La Jolla, California
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18
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June RK, Liu-Bryan R, Long F, Griffin TM. Emerging role of metabolic signaling in synovial joint remodeling and osteoarthritis. J Orthop Res 2016; 34:2048-2058. [PMID: 27605370 PMCID: PMC5365077 DOI: 10.1002/jor.23420] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [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: 06/30/2016] [Accepted: 08/31/2016] [Indexed: 02/04/2023]
Abstract
Obesity and associated metabolic diseases collectively referred to as the metabolic syndrome increase the risk of skeletal and synovial joint diseases, including osteoarthritis (OA). The relationship between obesity and musculoskeletal diseases is complex, involving biomechanical, dietary, genetic, inflammatory, and metabolic factors. Recent findings illustrate how changes in cellular metabolism and metabolic signaling pathways alter skeletal development, remodeling, and homeostasis, especially in response to biomechanical and inflammatory stressors. Consequently, a better understanding of the energy metabolism of diarthrodial joint cells and tissues, including bone, cartilage, and synovium, may lead to new strategies to treat or prevent synovial joint diseases such as OA. This rationale was the basis of a workshop presented at the 2016 Annual ORS Meeting in Orlando, FL on the emerging role of metabolic signaling in synovial joint remodeling and OA. The topics we covered included (i) the relationship between metabolic syndrome and OA in clinical and pre-clinical studies; (ii) the effect of biomechanical loading on chondrocyte metabolism; (iii) the effect of Wnt signaling on osteoblast carbohydrate and amino acid metabolism with respect to bone anabolism; and (iv) the role of AMP-activated protein kinase in chondrocyte energetic and biomechanical stress responses in the context of cartilage injury, aging, and OA. Although challenges exist for measuring in vivo changes in synovial joint tissue metabolism, the findings presented herein provide multiple lines of evidence to support a central role for disrupted cellular energy metabolism in the pathogenesis of OA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2048-2058, 2016.
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Affiliation(s)
- Ronald K. June
- Depts. of Mechanical & Industrial Engineering and Cell Biology & Neuroscience, Montana State University, Bozeman, MT, USA
| | - Ru Liu-Bryan
- VA San Diego Healthcare System, Dept. of Medicine, University of California San Diego, San Diego, California, USA
| | - Fanxing Long
- Dept. of Orthopaedic Surgery, Dept. of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Timothy M. Griffin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Depts. of Biochemistry and Molecular Biology, Physiology, and Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Doody KM, Stanford SM, Sacchetti C, Svensson MND, Coles CH, Mitakidis N, Kiosses WB, Bartok B, Fos C, Cory E, Sah RL, Liu-Bryan R, Boyle DL, Arnett HA, Mustelin T, Corr M, Esko JD, Tremblay ML, Firestein GS, Aricescu AR, Bottini N. Targeting phosphatase-dependent proteoglycan switch for rheumatoid arthritis therapy. Sci Transl Med 2016; 7:288ra76. [PMID: 25995222 DOI: 10.1126/scitranslmed.aaa4616] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite the availability of several therapies for rheumatoid arthritis (RA) that target the immune system, a large number of RA patients fail to achieve remission. Joint-lining cells, called fibroblast-like synoviocytes (FLS), become activated during RA and mediate joint inflammation and destruction of cartilage and bone. We identify RPTPσ, a transmembrane tyrosine phosphatase, as a therapeutic target for FLS-directed therapy. RPTPσ is reciprocally regulated by interactions with chondroitin sulfate or heparan sulfate containing extracellular proteoglycans in a mechanism called the proteoglycan switch. We show that the proteoglycan switch regulates FLS function. Incubation of FLS with a proteoglycan-binding RPTPσ decoy protein inhibited cell invasiveness and attachment to cartilage by disrupting a constitutive interaction between RPTPσ and the heparan sulfate proteoglycan syndecan-4. RPTPσ mediated the effect of proteoglycans on FLS signaling by regulating the phosphorylation and cytoskeletal localization of ezrin. Furthermore, administration of the RPTPσ decoy protein ameliorated in vivo human FLS invasiveness and arthritis severity in the K/BxN serum transfer model of RA. Our data demonstrate that FLS are regulated by an RPTPσ-dependent proteoglycan switch in vivo, which can be targeted for RA therapy. We envision that therapies targeting the proteoglycan switch or its intracellular pathway in FLS could be effective as a monotherapy or in combination with currently available immune-targeted agents to improve control of disease activity in RA patients.
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Affiliation(s)
- Karen M Doody
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Stephanie M Stanford
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Cristiano Sacchetti
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Mattias N D Svensson
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Charlotte H Coles
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Nikolaos Mitakidis
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - William B Kiosses
- Core Microscopy, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Beatrix Bartok
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Camille Fos
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Esther Cory
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Robert L Sah
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ru Liu-Bryan
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA. Veterans Affairs San Diego Healthcare System, Department of Medicine, University of California, San Diego, San Diego, CA 92161, USA
| | - David L Boyle
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | | | - Tomas Mustelin
- Research, MedImmune, AstraZeneca, One Medimmune Way, Gaithersburg, MD 20878, USA
| | - Maripat Corr
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Jeffrey D Esko
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michel L Tremblay
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Québec H3A 1A3, Canada. Department of Biochemistry, McGill University, Montréal, Québec H3A 1A3, Canada. Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada
| | - Gary S Firestein
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Nunzio Bottini
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
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Abstract
Objective AMP-activated protein kinase (AMPK) is a serine/threonine protein kinase critically involved in the regulation of cellular energy homeostasis. It is a central regulator of both lipid and glucose metabolism. Many studies have suggested that AMPK activation exert significant anti-inflammatory and immunosuppressive effects. In this study, we assessed whether targeted activation of AMPK inhibits inflammatory arthritis in vivo. Methods We tested the effect of A-769662, a specific AMPK agonist (60mg/kg/bid) in mouse models of antigen-induced arthritis (AIA) and passive K/BxN serum-induced arthritis. The passive K/BxN serum-induced arthritis model was also applied to AMPKα1-deficient mice. Joints were harvested and subjected to histological analysis. IL-6 expression was measured in both joint tissues and sera by ELISA. The effect of A-769662 on bone marrow derived macrophage (BMDM) response to stimulation with TLR2 and TLR4 agonists was tested in vitro. Results AMPK activation by A-769662 reduced inflammatory infiltration and joint damage in both mouse models. IL-6 expression in serum and arthritic joints was significantly decreased in A-769662-treated mice. AMPKα1 deficient mice mildly elicited an increase of clinical arthritis. IL-6 expression at both mRNA and protein levels, phosphorylation of p65 NF-κB and MAPK phosphorylation were inhibited by A-769662 in BMDMs stimulated with either TLR2 or TLR4 agonists. Conclusions AMPK activation by specific AMPK agonist A-769662 suppressed inflammatory arthritis in mice as well as IL-6 expression in serum and arthritic joints. These data suggest that targeted activation of AMPK has a potential to be an effective therapeutic strategy for IL-6 dependent inflammatory arthritis.
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Affiliation(s)
- Monica Guma
- Division of Rheumatology, Allergy and Immunology, UC San Diego School of Medicine, La Jolla, California, United States of America
- * E-mail: (MG); (RLB)
| | - Yun Wang
- Division of Rheumatology, Allergy and Immunology, UC San Diego School of Medicine, La Jolla, California, United States of America
| | - Benoit Viollet
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ru Liu-Bryan
- Division of Rheumatology, Allergy and Immunology, UC San Diego School of Medicine, La Jolla, California, United States of America
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, La Jolla, California, United States of America
- * E-mail: (MG); (RLB)
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Wang Y, Zhao X, Lotz M, Terkeltaub R, Liu-Bryan R. Mitochondrial biogenesis is impaired in osteoarthritis chondrocytes but reversible via peroxisome proliferator-activated receptor γ coactivator 1α. Arthritis Rheumatol 2015; 67:2141-53. [PMID: 25940958 DOI: 10.1002/art.39182] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/28/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The etiology of chondrocyte mitochondrial dysfunction in osteoarthritis (OA) is not completely understood. OA chondrocytes are deficient in the metabolic biosensors active AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT-1), which modulate the mitochondrial biogenesis "master regulator" peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α). Moreover, PGC-1α critically mediates AMPK anticatabolic activity in chondrocytes. The aim of this study was to test the hypothesis that mitochondrial biogenesis is deficient in human OA chondrocytes and that this deficiency functionally increases chondrocyte procatabolic responses, which are reversed by activation of the AMPK/SIRT-1/PGC-1α pathway. METHODS We assessed the expression and activity (phosphorylation) of AMPKα, SIRT-1, and PGC-1α in human knee chondrocytes and human and mouse knee cartilage, and we defined and compared the content and function of mitochondria, including oxidative phosphorylation and expression of mitochondrial biogenesis factors (mitochondrial transcriptional factor A [TFAM] and nuclear respiratory factors [NRFs]). RESULTS Human knee OA chondrocytes had a decreased mitochondrial biogenesis capacity, which was linked to reduced AMPKα activity and decreased expression of SIRT-1, PGC-1α, TFAM, NRF-1, and NRF-2. Human knee OA and aging mouse knee cartilage had decreased expression of TFAM and ubiquinol-cytochrome c reductase core protein, a subunit of mitochondrial complex III, in situ. Chondrocyte TFAM knockdown inhibited mitochondrial biogenesis and enhanced procatabolic responses to interleukin-1β. Finally, activation of AMPK by A-769662 increased PGC-1α expression via SIRT-1 and reversed impairments in mitochondrial biogenesis, oxidative phosphorylation, and intracellular ATP in human knee OA chondrocytes. CONCLUSION Mitochondrial biogenesis is deficient in human OA chondrocytes, and this deficiency promotes chondrocyte procatabolic responses. TFAM-mediated activation of the AMPK/SIRT-1/PGC-1α pathway reverses these effects, suggesting translational potential of pharmacologic AMPK activators to limit OA progression.
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Affiliation(s)
- Yun Wang
- University of California at San Diego, La Jolla
| | - Xianling Zhao
- VA San Diego Healthcare System, San Diego, California
| | - Martin Lotz
- The Scripps Research Institute, La Jolla, California
| | - Robert Terkeltaub
- University of California at San Diego, La Jolla, and VA San Diego Healthcare System, San Diego, California
| | - Ru Liu-Bryan
- University of California at San Diego, La Jolla, and VA San Diego Healthcare System, San Diego, California
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Zhao X, Petursson F, Viollet B, Lotz M, Terkeltaub R, Liu-Bryan R. Peroxisome proliferator-activated receptor γ coactivator 1α and FoxO3A mediate chondroprotection by AMP-activated protein kinase. Arthritis Rheumatol 2015; 66:3073-82. [PMID: 25047750 DOI: 10.1002/art.38791] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 07/17/2014] [Indexed: 12/19/2022]
Abstract
OBJECTIVE AMP-activated protein kinase (AMPK) inhibits chondrocyte procatabolic responses to inflammation and biomechanical injury. This study was undertaken to test the hypothesis that peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and FoxO3A, 2 major AMPK downstream targets, mediate the chondroprotective effect of AMPK activation. METHODS We assessed the activity of AMPKα (threonine 172 phosphorylation) and the expression of PGC-1α and FoxO3A in human chondrocytes and AMPKα1- or AMPKα2-knockout mouse chondrocytes by Western blotting, and in mouse knee cartilage by immunohistochemistry. We also knocked down or overexpressed PGC-1α and FoxO3A by small interfering RNA or plasmid DNA transfection, respectively. We assessed mitochondrial superoxide generation using MitoSOX Red. RESULTS Expression of PGC-1α and FoxO3A was enhanced by pharmacologic AMPK activator A-769662 but impaired in AMPKα1(-/-) or AMPKα2(-/-) mouse chondrocytes. Reduced expression of PGC-1α and FoxO3A was observed in mouse knee instability-induced osteoarthritis (OA) cartilage and in aged C57BL/6 mouse knee cartilage. Knockdown of PGC-1α and FoxO3A enhanced, but limited the ability of A-769662 to inhibit, phosphorylation of p65 NF-κB (Ser(536) ) and procatabolic responses induced by inflammatory cytokines. Forced expression of PGC-1α and FoxO3A induced increased expression of superoxide dismutase 2 (SOD2) and catalase, but A-769662 failed to increase the expression of SOD2 and catalase in either PGC-1α- or FoxO3A-knockdown chondrocytes. Last, menadione-induced superoxide generation was inhibited by AMPK pharmacologic activators and by overexpression of PGC-1α or FoxO3A. CONCLUSION PGC-1α and FoxO3A limit oxidative stress and at least partially mediate the capacity of AMPK activity to block procatabolic responses in chondrocytes, and therefore have the potential to inhibit the progression of cartilage damage in OA.
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Affiliation(s)
- Xianling Zhao
- VA San Diego Medical Center and University of California, San Diego
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Abstract
Chronic, low-grade inflammation in osteoarthritis (OA) contributes to symptoms and disease progression. Effective disease-modifying OA therapies are lacking, but better understanding inflammatory pathophysiology in OA could lead to transformative therapy. Networks of diverse innate inflammatory danger signals, including complement and alarmins, are activated in OA. Through inflammatory mediators, biomechanical injury and oxidative stress compromise the viability of chondrocytes, reprogramming them to hypertrophic differentiation and proinflammatory and pro-catabolic responses. Integral to this reprogramming are 'switching' pathways in transcriptional networks, other than the well-characterized effects of NFκB and mitogen-activated protein kinase signalling; HIF-2α transcriptional signalling and ZIP8-mediated Zn(2+) uptake, with downstream MTF1 transcriptional signalling, have been implicated but further validation is required. Permissive factors, including impaired bioenergetics via altered mitochondrial function and decreased activity of bioenergy sensors, interact with molecular inflammatory responses and proteostasis mechanisms such as the unfolded protein response and autophagy. Bioenergy-sensing by AMPK and SIRT1 provides 'stop signals' for oxidative stress, inflammatory, and matrix catabolic processes in chondrocytes. The complexity of molecular inflammatory processes in OA and the involvement of multiple inflammatory mediators in tissue repair responses, raises daunting questions about how to therapeutically target inflammatory processes and macroscopic inflammation in OA. Bioenergy sensing might provide a pragmatic 'entry point'.
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Affiliation(s)
- Ru Liu-Bryan
- San Diego VA Healthcare System and Division of Rheumatology, Allergy and Immunology, Department of Medicine, University of California San Diego, 111K, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - Robert Terkeltaub
- San Diego VA Healthcare System and Division of Rheumatology, Allergy and Immunology, Department of Medicine, University of California San Diego, 111K, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
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Sacchetti C, Liu-Bryan R, Magrini A, Rosato N, Bottini N, Bottini M. Polyethylene-glycol-modified single-walled carbon nanotubes for intra-articular delivery to chondrocytes. ACS Nano 2014; 8:12280-91. [PMID: 25415768 PMCID: PMC4373402 DOI: 10.1021/nn504537b] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Osteoarthritis (OA) is a common and debilitating degenerative disease of articular joints for which no disease-modifying medical therapy is currently available. Inefficient delivery of pharmacologic agents into cartilage-resident chondrocytes after systemic administration has been a limitation to the development of anti-OA medications. Direct intra-articular injection enables delivery of high concentrations of agents in close proximity to chondrocytes; however, the efficacy of this approach is limited by the fast clearance of small molecules and biomacromolecules after injection into the synovial cavity. Coupling of pharmacologic agents with drug delivery systems able to enhance their residence time and cartilage penetration can enhance the effectiveness of intra-articularly injected anti-OA medications. Herein we describe an efficient intra-articular delivery nanosystem based on single-walled carbon nanotubes (SWCNTs) modified with polyethylene glycol (PEG) chains (PEG-SWCNTs). We show that PEG-SWCNTs are capable to persist in the joint cavity for a prolonged time, enter the cartilage matrix, and deliver gene inhibitors into chondrocytes of both healthy and OA mice. PEG-SWCNT nanoparticles did not elicit systemic or local side effects. Our data suggest that PEG-SWCNTs represent a biocompatible and effective nanocarrier for intra-articular delivery of agents to chondrocytes.
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Affiliation(s)
- Cristiano Sacchetti
- Inflammatory and Infectious Disease Center, Sanford Burnham Medical Research Institute, La Jolla, California 92037, United States
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
| | - Ru Liu-Bryan
- Department of Medicine, VA Medical Center, University of California San Diego, San Diego, California 92093, United States, an
| | - Andrea Magrini
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00173, Italy
| | - Nicola Rosato
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00173, Italy
| | - Nunzio Bottini
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
- Address correspondence to ,
| | - Massimo Bottini
- Inflammatory and Infectious Disease Center, Sanford Burnham Medical Research Institute, La Jolla, California 92037, United States
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, United States
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome 00173, Italy
- Address correspondence to ,
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Wang Y, Viollet B, Terkeltaub R, Liu-Bryan R. AMP-activated protein kinase suppresses urate crystal-induced inflammation and transduces colchicine effects in macrophages. Ann Rheum Dis 2014; 75:286-94. [PMID: 25362043 DOI: 10.1136/annrheumdis-2014-206074] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 10/12/2014] [Indexed: 12/30/2022]
Abstract
OBJECTIVE AMP-activated protein kinase (AMPK) is metabolic biosensor with anti-inflammatory activities. Gout is commonly associated with excesses in soluble urate and in nutrition, both of which suppress tissue AMPK activity. Gout is driven by macrophage-mediated inflammation transduced partly by NLRP3 inflammasome activation and interleukin (IL)-1β release. Hence, we tested the hypothesis that AMPK activation limits monosodium urate (MSU) crystal-induced inflammation. METHODS We studied bone marrow-derived macrophages (BMDMs) from AMPKα1 knockout and wild-type mice, and assessed the selective AMPK pharmacological activator A-769662 and a low concentration (10 nM) of colchicine. We examined phosphorylation (activation) of AMPKα Thr172, NLRP3 mRNA expression, and caspase-1 cleavage and IL-1β maturation using western blot and quantitative RT-PCR approaches. We also assessed subcutaneous murine air pouch inflammatory responses to MSU crystals in vivo. RESULTS MSU crystals suppressed phosphorylation of AMPKα in BMDMs. Knockout of AMPKα1 enhanced, and, conversely, A-769662-inhibited MSU crystal-induced inflammatory responses including IL-1β and CXCL1 release in vitro and in vivo. A-769662 promoted AMPK-dependent macrophage anti-inflammatory M2 polarisation and inhibited NLRP3 gene expression, activation of caspase-1 and IL-1β. Colchicine, at low concentration (10 nM) achieved in gout flare prophylaxis dosing, promoted phosphorylation of AMPKα and macrophage M2 polarisation, and reduced activation of caspase-1 and release of IL-1β and CXCL1 by MSU crystals in BMDMs in vitro. CONCLUSIONS AMPK activity limits MSU crystal inflammation in vitro and in vivo, and transduces multiple anti-inflammatory effects of colchicine in macrophages. Targeting increased and sustained AMPK activation in inflammatory cells merits further investigation for enhancing efficacy of prophylaxis and treatment of gouty inflammation.
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Affiliation(s)
- Yun Wang
- Depatment of Medicine, UCSD, San Diego, California, USA
| | - Benoit Viollet
- INSERM, U1016, Institut Cochin, Paris, France CNRS, UMR8104, Paris, France Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Robert Terkeltaub
- Depatment of Medicine, UCSD, San Diego, California, USA VA San Diego Medical Center, San Diego, California, USA
| | - Ru Liu-Bryan
- Depatment of Medicine, UCSD, San Diego, California, USA VA San Diego Medical Center, San Diego, California, USA
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Fernandez I, Harlow L, Zang Y, Liu-Bryan R, Ridgway W, Clemens P, Ascherman D. P.14.9 Functional redundancy of MyD88-dependent signaling pathways in a murine model of histidyl-tRNA synthetase-induced myositis. Neuromuscul Disord 2013. [DOI: 10.1016/j.nmd.2013.06.617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
This review focuses on the recent advancements in the understanding of innate immunity in the pathogenesis of osteoarthritis, particularly with attention to the roles of damage-associated molecular patterns (DAMPs), pattern recognition receptors (PPRs), and complement in synovitis development and cartilage degradation. Endogenous molecular products derived from cellular stress and extracellular matrix disruption can function as DAMPs to induce inflammatory responses and pro-catabolic events in vitro and promote synovitis and cartilage degradation in vivo via PRRs. Some of the DAMPs and PRRs display various capacities in driving synovitis and/or cartilage degradation in different models of animal studies. New findings reveal that the inflammatory complement cascade plays a key in the pathogenesis of OA. Crosstalk between joint tissues such as synovium and cartilage communicated at the cellular level within the innate immune inflammatory network is implicated to play an important role in OA progression. Further studies on how the innate immune inflammatory network impacts the OA disease process at different stages of progression will lead to the development of new therapeutic strategies.
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Affiliation(s)
- Ru Liu-Bryan
- Veterans Affairs Medical Center and University of California San Diego, 3350 La Jolla Village Drive, 111K, San Diego, CA 92161, USA.
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Petursson F, Husa M, June R, Lotz M, Terkeltaub R, Liu-Bryan R. Linked decreases in liver kinase B1 and AMP-activated protein kinase activity modulate matrix catabolic responses to biomechanical injury in chondrocytes. Arthritis Res Ther 2013; 15:R77. [PMID: 23883619 PMCID: PMC3979085 DOI: 10.1186/ar4254] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 07/25/2013] [Indexed: 12/12/2022] Open
Abstract
Introduction AMP-activated protein kinase (AMPK) maintains cultured chondrocyte matrix homeostasis in response to inflammatory cytokines. AMPK activity is decreased in human knee osteoarthritis (OA) chondrocytes. Liver kinase B1 (LKB1) is one of the upstream activators of AMPK. Hence, we examined the relationship between LKB1 and AMPK activity in OA and aging cartilages, and in chondrocytes subjected to inflammatory cytokine treatment and biomechanical compression injury, and performed translational studies of AMPK pharmacologic activation. Methods We assessed activity (phosphorylation) of LKB1 and AMPKα in mouse knee OA cartilage, in aging mouse cartilage (6 to 24 months), and in chondrocytes after mechanical injury by dynamic compression, via immunohistochemistry or western blot. We knocked down LKB1 by siRNA transfection. Nitric oxide, matrix metalloproteinase (MMP)-3, and MMP-13 release were measured by Griess reaction and ELISA, respectively. Results Knockdown of LKB1 attenuated chondrocyte AMPK activity, and increased nitric oxide, MMP-3 and MMP-13 release (P <0.05) in response to IL-1β and TNFα. Both LKB1 and AMPK activity were decreased in mouse knee OA and aged knee cartilage, and in bovine chondrocytes after biomechanical injury. Pretreatment of bovine chondrocytes with AMPK activators AICAR and A-769662 inhibited both AMPKα dephosphorylation and catabolic responses after biomechanical injury. Conclusion LKB1 is required for chondrocyte AMPK activity, thereby inhibiting matrix catabolic responses to inflammatory cytokines. Concurrent loss of LKB1 and AMPK activity in articular chondrocytes is associated with OA, aging and biomechanical injury. Conversely, pharmacologic AMPK activation attenuates catabolic responses to biomechanical injury, suggesting a potentially novel approach to inhibit OA development and progression.
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Fernandez I, Harlow L, Zang Y, Liu-Bryan R, Ridgway WM, Clemens PR, Ascherman DP. Functional redundancy of MyD88-dependent signaling pathways in a murine model of histidyl-transfer RNA synthetase-induced myositis. J Immunol 2013; 191:1865-72. [PMID: 23842751 DOI: 10.4049/jimmunol.1203070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We have previously shown that i.m. administration of bacterially expressed murine histidyl-tRNA synthetase (HRS) triggers florid muscle inflammation (relative to appropriate control proteins) in various congenic strains of mice. Because severe disease develops even in the absence of adaptive immune responses to HRS, we sought to identify innate immune signaling components contributing to our model of HRS-induced myositis. In vitro stimulation assays demonstrated HRS-mediated activation of HEK293 cells transfected with either TLR2 or TLR4, revealing an excitatory capacity exceeding that of other bacterially expressed fusion proteins. Corresponding to this apparent functional redundancy of TLR signaling pathways, HRS immunization of B6.TLR2(-/-) and B6.TLR4(-/-) single-knockout mice yielded significant lymphocytic infiltration of muscle tissue comparable to that produced in C57BL/6 wild-type mice. In contrast, concomitant elimination of TLR2 and TLR4 signaling in B6.TLR2(-/-).TLR4(-/-) double-knockout mice markedly reduced the severity of HRS-induced muscle inflammation. Complementary subfragment analysis demonstrated that aa 60-90 of HRS were absolutely required for in vitro as well as in vivo signaling via these MyD88-dependent TLR pathways--effects mediated, in part, through preferential binding of exogenous ligands capable of activating specific TLRs. Collectively, these experiments indicate that multiple MyD88-dependent signaling cascades contribute to this model of HRS-induced myositis, underscoring the antigenic versatility of HRS and confirming the importance of innate immunity in this system.
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Affiliation(s)
- Irina Fernandez
- Division of Rheumatology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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Terkeltaub R, Yang B, Lotz M, Liu-Bryan R. Chondrocyte AMP-activated protein kinase activity suppresses matrix degradation responses to proinflammatory cytokines interleukin-1β and tumor necrosis factor α. ACTA ACUST UNITED AC 2011; 63:1928-37. [PMID: 21400477 DOI: 10.1002/art.30333] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) stimulate chondrocyte matrix catabolic responses, thereby compromising cartilage homeostasis in osteoarthritis (OA). AMP-activated protein kinase (AMPK), which regulates energy homeostasis and cellular metabolism, also exerts antiinflammatory effects in multiple tissues. This study was undertaken to test the hypothesis that AMPK activity limits chondrocyte matrix catabolic responses to IL-1β and TNFα. METHODS Expression of AMPK subunits was examined, and AMPKα activity was ascertained by the phosphorylation status of AMPKα Thr(172) in human knee articular chondrocytes and cartilage by Western blotting and immunohistochemistry, respectively. Procatabolic responses to IL-1β and TNFα, such as release of glycosaminoglycan, nitric oxide, and matrix metalloproteinases 3 and 13 were determined by dimethylmethylene blue assay, Griess reaction, and Western blotting, respectively, in cartilage explants and chondrocytes with and without knockdown of AMPKα by small interfering RNA. RESULTS Normal human knee articular chondrocytes expressed AMPKα1, α2, β1, β2, and γ1 subunits. AMPK activity was constitutively present in normal articular chondrocytes and cartilage, but decreased in OA articular chondrocytes and cartilage and in normal chondrocytes treated with IL-1β and TNFα. Knockdown of AMPKα resulted in enhanced catabolic responses to IL-1β and TNFα in chondrocytes. Moreover, AMPK activators suppressed cartilage/chondrocyte procatabolic responses to IL-1β and TNFα and the capacity of TNFα and CXCL8 (IL-8) to induce type X collagen expression. CONCLUSION Our findings indicate that AMPK activity is reduced in OA cartilage and in chondrocytes following treatment with IL-1β or TNFα. AMPK activators attenuate dephosphorylation of AMPKα and procatabolic responses in chondrocytes induced by these cytokines. These observations suggest that maintenance of AMPK activity supports cartilage homeostasis by protecting cartilage matrix from inflammation-induced degradation.
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Affiliation(s)
- Robert Terkeltaub
- VA San Diego Medical Center and University of California, San Diego, CA, USA
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Liu-Bryan R, Terkeltaub R. Chondrocyte innate immune myeloid differentiation factor 88-dependent signaling drives procatabolic effects of the endogenous Toll-like receptor 2/Toll-like receptor 4 ligands low molecular weight hyaluronan and high mobility group box chromosomal protein 1 in mice. ACTA ACUST UNITED AC 2010; 62:2004-12. [PMID: 20506365 DOI: 10.1002/art.27475] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Toll-like receptor 2 (TLR-2)/TLR-4-mediated innate immunity serves as a frontline antimicrobial host defense, but also modulates tissue remodeling and repair responses to endogenous ligands released during low-grade inflammation. We undertook the present study to assess whether the endogenous TLR-2/TLR-4 ligands low molecular weight hyaluronan (LMW-HA) and high mobility group box chromosomal protein 1 (HMGB-1), which are increased in osteoarthritic (OA) joints, drive procatabolic chondrocyte responses dependent on TLR-2 and TLR-4 signaling through the cytosolic adaptor myeloid differentiation factor 88 (MyD88). METHODS We studied mature femoral head cap cartilage explants and immature primary knee articular chondrocytes from TLR-2/TLR-4-double-knockout, MyD88-knockout, and congenic wild-type mice. Generation of nitric oxide (NO), degradation of hyaluronan, release of HMGB-1, matrix metalloproteinase 3 (MMP-3), and MMP-13, and protein expression of type X collagen were assessed by Griess reaction and Western blotting analyses. Expression of messenger RNA for type II and type X collagen, MMP-13, and RUNX-2 was examined by real-time quantitative reverse transcription-polymerase chain reaction. RESULTS Interleukin-1beta and TLR-2 and TLR-4 ligands induced both HMGB-1 release from chondrocytes and extracellular LMW-HA generation in normal chondrocytes. TLR-2/TLR-4(-/-) and MyD88(-/-) mouse cartilage explants and chondrocytes lost the capacity to mount procatabolic responses to both LMW-HA and HMGB-1, demonstrated by >95% suppression of NO production (P < 0.01), and attenuated induction of MMP-3 and MMP-13. Combined deficiency of TLR-2/TLR-4, or of MyD88 alone, also attenuated release of NO and blunted induction of MMP-3 and MMP-13 release. MyD88 was necessary for HMGB-1 and hyaluronidase 2 (which generates LMW-HA) to induce chondrocyte hypertrophy, which is implicated in OA progression. CONCLUSION MyD88-dependent TLR-2/TLR-4 signaling is essential for procatabolic responses to LMW-HA and HMGB-1, and MyD88 drives chondrocyte hypertrophy. Therefore, LMW-HA and HMGB-1 act as innate immune cytokine-like signals with the potential to modulate chondrocyte differentiation and function in OA progression.
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Affiliation(s)
- Ru Liu-Bryan
- VA Medical Center, San Diego, California 92161, USA.
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Hoffman HM, Scott P, Mueller JL, Misaghi A, Stevens S, Yancopoulos GD, Murphy A, Valenzuela DM, Liu-Bryan R. Role of the leucine-rich repeat domain of cryopyrin/NALP3 in monosodium urate crystal-induced inflammation in mice. ACTA ACUST UNITED AC 2010; 62:2170-9. [PMID: 20506351 DOI: 10.1002/art.27456] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE The mechanism by which monosodium urate monohydrate (MSU) crystals intracellularly activate the cryopyrin inflammasome is unknown. The aim of this study was to use a mouse molecular genetics-based approach to test whether the leucine-rich repeat (LRR) domain of cryopyrin is required for MSU crystal-induced inflammation. METHODS Cryopyrin-knockout lacZ (Cryo(-Z/-Z)) mice and mice with the cryopyrin LRR domain deleted and fused to the lacZ reporter (Cryo(DeltaLRR Z/DeltaLRR Z)) were generated using bacterial artificial chromosome-based targeting vectors, which allow for large genomic deletions. Bone marrow-derived macrophages from Cryo(DeltaLRR Z/DeltaLRR Z) mice, Cryo(-Z/-Z) mice, and congenic wild-type (WT) mice were challenged with endotoxin-free MSU crystals under serum-free conditions. Phagocytosis and cytokine expression were assessed by flow cytometry and enzyme-linked immunosorbent assay. MSU crystals also were injected into mouse synovial-like subcutaneous air pouches. The in vivo inflammatory responses were examined. RESULTS Release of interleukin-1beta (IL-1beta), but not CXCL1 and tumor necrosis factor alpha, was impaired in Cryo(DeltaLRR Z/DeltaLRR Z) and Cryo(-Z/-Z) mouse bone marrow-derived macrophages compared with WT mouse bone marrow-derived macrophages in response to not only MSU crystals but also other known stimuli that activate the cryopyrin inflammasome. In addition, a comparable percentage of MSU crystals taken up by each type of bone marrow-derived macrophage was observed. Moreover, total leukocyte infiltration in the air pouch and IL-1beta production were attenuated in Cryo(-Z/-Z) and Cryo(DeltaLRR Z/DeltaLRR Z) mice at 6 hours postinjection of MSU crystals compared with WT mice. CONCLUSION MSU crystal-induced inflammatory responses were comparably attenuated both in vitro and in vivo in Cryo(DeltaLRR Z/DeltaLRR Z) and Cryo(-Z/-Z) mice. Hence, the LRR domain of cryopyrin plays a role in mediating MSU crystal-induced inflammation in this model.
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Guma M, Ronacher L, Liu-Bryan R, Takai S, Karin M, Corr M. Caspase 1-independent activation of interleukin-1beta in neutrophil-predominant inflammation. ACTA ACUST UNITED AC 2010; 60:3642-50. [PMID: 19950258 DOI: 10.1002/art.24959] [Citation(s) in RCA: 232] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Interleukin-1beta (IL-1beta) is a key cytokine linked to the pathogenesis of acute arthritis. Caspase 1, neutrophil elastase, and chymase all process proIL-1beta to its biologically active form. This study was undertaken to examine the potential contributions of each of these proteases in experimental models of inflammatory arthritis. METHODS Caspase 1-deficient (Casp1-/-) and wild-type (WT) mice were tested for their response to arthritogenic K/BxN serum transfer for induction of arthritis or injection of monosodium urate monohydrate (MSU) crystals for induction of peritonitis. All mice were prophylactically treated with inhibitors of neutrophil elastase or chymase. Arthritic paws were tested for the presence of IL-1beta protein by enzyme-linked immunosorbent assay and Western blotting. Neutrophils and mast cells from WT and mutant mice were tested for their ability to secrete IL-1beta after in vitro stimulation, in the presence of protease inhibitors. RESULTS Casp1-/- and WT mice developed paw swelling to the same extent in the K/BxN serum transfer-induced arthritis model. MSU crystal injection into Casp1-/- mice also resulted in neutrophil influx and production of measurable peritoneal IL-1beta protein. Both of these responses were attenuated with neutrophil elastase inhibitors. K/BxN serum transfer-induced arthritis was also reduced by treatment with a chymase inhibitor. Casp1-/- neutrophils and mast cells, when exposed to MSU crystals, secreted similar amounts of IL-1beta protein upon in vitro stimulation with lipopolysaccharide, albeit at lower levels than that secreted by WT cells. Elastase and chymase inhibitors reduced the amount of IL-1beta released by these cells. CONCLUSION The production of IL-1beta by neutrophils and mast cells is not exclusively dependent on caspase 1, and other proteases can compensate for the loss of caspase 1 in vivo. These pathways might therefore compromise the caspase 1-targeted therapies in neutrophil-predominant arthritis.
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Affiliation(s)
- Monica Guma
- University of California at San Diego, La Jolla
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Torres R, Macdonald L, Croll SD, Reinhardt J, Dore A, Stevens S, Hylton DM, Rudge JS, Liu-Bryan R, Terkeltaub RA, Yancopoulos GD, Murphy AJ. Hyperalgesia, synovitis and multiple biomarkers of inflammation are suppressed by interleukin 1 inhibition in a novel animal model of gouty arthritis. Ann Rheum Dis 2009; 68:1602-8. [PMID: 19528034 DOI: 10.1136/ard.2009.109355] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystal-induced interleukin 1 beta (IL1beta) release contributes to inflammation in subcutaneous air pouch and peritoneal models of acute gout and pseudogout. However, consequences of IL1 inhibition have not been explored in more clinically relevant models of crystal-induced arthritis. OBJECTIVE To develop a novel mouse model of acute gouty ankle arthritis and use it to assess the effects of genetic deletion of IL1 receptor type (IL1R1) and of exogenous mIL1 Trap (a high-affinity blocker of mouse IL1alpha and IL1beta) on pain, synovitis and systemic inflammatory biomarkers. METHODS MSU crystals were injected into the mouse ankle joint and pain and ankle swelling were measured over 4 days. The effects of IL1 inhibition were determined in this model, and in the comparator models of crystal-induced peritonitis and subcutaneous air pouch inflammation. RESULTS Both IL1R1-null mice and mice pretreated with mIL1 Trap showed reduced neutrophil influx in MSU and CPPD crystal-induced peritonitis and air pouch models (p<0.05). In the ankle joint model, both IL1R1 knockout mice and pretreatment with mIL1 Trap were associated with significant reductions in MSU crystal-induced elevations in hyperalgesia, inflammation, serum amyloid A and the levels of multiple inflammatory cytokines and chemokines (p<0.05). Additionally, it was found that administration of mIL1 Trap after MSU crystal injection reduced established hyperalgesia and ankle swelling. CONCLUSIONS IL1 inhibition both prevented and relieved pain and ankle joint inflammation in response to intra-articular MSU crystals in mice. Results suggested that IL1 Trap has the potential to both prevent and treat gouty arthritis.
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Affiliation(s)
- R Torres
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Rd, Tarrytown, NY 10591, USA.
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Nguyen MTA, Favelyukis S, Nguyen AK, Reichart D, Scott PA, Jenn A, Liu-Bryan R, Glass CK, Neels JG, Olefsky JM. A subpopulation of macrophages infiltrates hypertrophic adipose tissue and is activated by free fatty acids via Toll-like receptors 2 and 4 and JNK-dependent pathways. J Biol Chem 2007; 282:35279-92. [PMID: 17916553 DOI: 10.1074/jbc.m706762200] [Citation(s) in RCA: 749] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Obesity and type 2 diabetes are characterized by decreased insulin sensitivity, elevated concentrations of free fatty acids (FFAs), and increased macrophage infiltration in adipose tissue (AT). Here, we show that FFAs can cause activation of RAW264.7 cells primarily via the JNK signaling cascade and that TLR2 and TLR4 are upstream of JNK and help transduce FFA proinflammatory signals. We also demonstrate that F4/80(+)CD11b(+)CD11c(+) bone marrow-derived dendritic cells (BMDCs) have heightened proinflammatory activity compared with F4/80(+)CD11b(+)CD11c(-) bone marrow-derived macrophages and that the proinflammatory activity and JNK phosphorylation of BMDCs, but not bone marrow-derived macrophages, was further increased by FFA treatment. F4/80(+)CD11b(+)CD11c(+) cells were found in AT, and the proportion and number of these cells in AT is increased in ob/ob mice and by feeding wild type mice a high fat diet for 1 and 12 weeks. AT F4/80(+)CD11b(+)CD11c(+) cells express increased inflammatory markers compared with F4/80(+)CD11b(+)CD11c(-) cells, and FFA treatment increased inflammatory responses in these cells. In addition, we found that CD11c expression is increased in skeletal muscle of high fat diet-fed mice and that conditioned medium from FFA-treated wild type BMDCs, but not TLR2/4 DKO BMDCs, can induce insulin resistance in L6 myotubes. Together our results show that FFAs can activate CD11c(+) myeloid proinflammatory cells via TLR2/4 and JNK signaling pathways, thereby promoting inflammation and subsequent cellular insulin resistance.
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Affiliation(s)
- M T Audrey Nguyen
- Division of Endocrinology-Metabolism, University of California, San Diego, La Jolla, California 92093, USA.
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Scott P, Ma H, Viriyakosol S, Terkeltaub R, Liu-Bryan R. Engagement of CD14 mediates the inflammatory potential of monosodium urate crystals. J Immunol 2006; 177:6370-8. [PMID: 17056568 DOI: 10.4049/jimmunol.177.9.6370] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Phagocyte ingestion of monosodium urate (MSU) crystals can induce proinflammatory responses and trigger acute gouty inflammation. Alternatively, the uptake of MSU crystals by mature macrophages can be noninflammatory and promote resolution of gouty inflammation. Macrophage activation by extracellular MSU crystals involves apparent recognition and ingestion mediated by TLR2 and TLR4, with subsequent intracellular recognition linked to caspase-1 activation and IL-1beta processing driven by the NACHT-LRR-PYD-containing protein-3 inflammasome. In this study, we examined the potential role in gouty inflammation of CD14, a phagocyte-expressed pattern recognition receptor that functionally interacts with both TLR2 and TLR4. MSU crystals, but not latex beads, directly bound recombinant soluble (s) CD14 in vitro. CD14(-/-) bone marrow-derived macrophages (BMDMs) demonstrated unimpaired phagocytosis of MSU crystals but reduced p38 phosphorylation and approximately 90% less IL-1beta and CXCL1 release. Attenuated MSU crystal-induced IL-1beta release in CD14(-/-) BMDMs was mediated by decreased pro-IL-1beta protein expression and additionally by decreased caspase-1 activation and IL-1beta processing consistent with diminished NACHT-LRR-PYD-containing protein-3 inflammasome activation. Coating of MSU crystals with sCD14, but not sTLR2 or sTLR4, restored IL-1beta and CXCL1 production in CD14(-/-) BMDMs in vitro. Gain of function of CD14 directly enhanced TLR4-mediated signaling in response to MSU crystals in transfected Chinese hamster ovary cells in vitro. Last, MSU crystal-induced leukocyte influx at 6 h was reduced by approximately 75%, and local induction of IL-1beta decreased by >80% in CD14(-/-) mouse s.c. air pouches in vivo. We conclude that engagement of CD14 is a central determinant of the inflammatory potential of MSU crystals.
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Affiliation(s)
- Peter Scott
- Veterans Affairs Medical Center, Department of Medicine, University of California-San Diego, San Diego, CA 92161, USA
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Abstract
Gout has long been recognized as a disease of recurrent bouts of acute inflammation that undergo self-resolution. This inflammation is triggered by the body's response to monosodium urate (MSU) crystals. In this paper, we focus on recent studies that describe how interactions of MSU crystals with the components of the innate immune system trigger acute gouty inflammation as well as mechanisms that are involved in the resolution of this inflammation. Specifically, we describe how toll-like receptors mediate the uptake of MSU crystals involved in the initiation and resolution of gouty inflammation. We also describe recent findings on the role of apoptotic clearance in the resolution of gouty inflammation. In addition, how therapies used to treat gout act on the innate immune system to inhibit MSU crystal-induced inflammation and promote the resolution of inflammation is discussed.
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Abstract
In most mammals purine degradation ultimately leads to the formation of allantoin. Humans lack the enzyme uricase, which catalyzes the conversion of uric acid to allantoin. The resulting higher level of uric acid has been hypothesized to play a role as an antioxidant. Hyperuricaemia is usually an asymptomatic condition which is hypothesized to play a role in cardiovascular disease and hypertension. Some hyperuricaemic individuals develop gout, an inflammatory arthritis caused by the deposition of monosodium urate crystals in joints. Over time, acute intermittent gouty arthritis can develop into a chronic condition with deposits of monosodium urate (MSU) crystals in joints and as tophi. The mechanisms by which MSU crystals lead to an acute inflammatory arthritis are under investigation and current knowledge is reviewed here. Treatment of gout includes management of acute flares with anti-inflammatory medications such as non-steroidal anti-inflammatory drugs or corticosteroids and long term management with urate-lowering therapy when indicated. Future directions in the treatment of gout, in part guided by a better understanding of pathophysiology, are discussed.
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Affiliation(s)
- D Masseoud
- Division of Rheumatology, Emory University School of Medicine/The Emory Clinic, 1365A Clifton Rd NE, 4th floor, Atlanta, GA 30322, USA
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Liu-Bryan R, Lioté F. Monosodium urate and calcium pyrophosphate dihydrate (CPPD) crystals, inflammation, and cellular signaling. Joint Bone Spine 2005; 72:295-302. [PMID: 15990350 DOI: 10.1016/j.jbspin.2004.12.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Accepted: 12/15/2004] [Indexed: 11/20/2022]
Abstract
Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystals are responsible for acute synovial inflammation but also contribute to cartilage degradation and bone lesions within the joint. They activate multiple signal transduction pathways leading to cell activation and recruitment. Some signalling pathways are activated by both types of crystals, and other pathways may only be activated by one type depending on cell type, namely neutrophils, monocytes, macrophages, synovial fibroblasts, endothelial cells and chondrocytes. Cascades of activated proteins involve cytoplasmic membrane related proteins (FAK complex, Src family tyrosine kinases), but also MAPK and NF-kB pathways, leading to NO, prostanoid and cytokine production, and protease activation. This review will also focus on potential therapeutic targets related to cellular signalling in MSU and CPPD crystal-induced inflammation.
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Affiliation(s)
- Ru Liu-Bryan
- Veteran Affairs Medical Center, University of California, MC111K, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
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Liu-Bryan R, Scott P, Sydlaske A, Rose DM, Terkeltaub R. Innate immunity conferred by Toll-like receptors 2 and 4 and myeloid differentiation factor 88 expression is pivotal to monosodium urate monohydrate crystal-induced inflammation. ACTA ACUST UNITED AC 2005; 52:2936-46. [PMID: 16142712 DOI: 10.1002/art.21238] [Citation(s) in RCA: 274] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE In gout, incompletely defined molecular factors alter recognition of dormant articular and bursal monosodium urate monohydrate (MSU) crystal deposits, thereby inducing self-limiting bouts of characteristically severe neutrophilic inflammation. To define primary determinants of cellular recognition, uptake, and inflammatory responses to MSU crystals, we conducted a study to test the role of Toll-like receptor 2 (TLR-2), TLR-4, and the cytosolic TLR adapter protein myeloid differentiation factor 88 (MyD88), which are centrally involved in innate immune recognition of microbial pathogens. METHODS We isolated bone marrow-derived macrophages (BMDMs) in TLR-2-/-, TLR-4-/-, MyD88-/-, and congenic wild-type mice, and assessed phagocytosis and cytokine expression in response to endotoxin-free MSU crystals under serum-free conditions. MSU crystals also were injected into mouse synovium-like subcutaneous air pouches. RESULTS TLR-2-/-, TLR-4-/-, and MyD88-/- BMDMs demonstrated impaired uptake of MSU crystals in vitro. MSU crystal-induced production of interleukin-1beta (IL-1beta), tumor necrosis factor alpha, keratinocyte-derived cytokine/growth-related oncogene alpha, and transforming growth factor beta1 also were significantly suppressed in TLR-2-/- and TLR-4-/- BMDMs and were blunted in MyD88-/- BMDMs in vitro. Neutrophil influx and local induction of IL-1beta in subcutaneous air pouches were suppressed 6 hours after injection of MSU crystals in TLR-2-/- and TLR-4-/- mice and were attenuated in MyD88-/- mice. CONCLUSION The murine host requires TLR-2, TLR-4, and MyD88 for macrophage activation and development of full-blown neutrophilic, air pouch inflammation in response to MSU crystals. Our findings implicate innate immune cellular recognition of naked MSU crystals by specific TLRs as a major factor in determining the inflammatory potential of MSU crystal deposits and the course of gouty arthritis.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/metabolism
- Arthritis, Gouty/genetics
- Arthritis, Gouty/immunology
- Arthritis, Gouty/metabolism
- Bone Marrow Cells/drug effects
- Bone Marrow Cells/metabolism
- Cytokines/metabolism
- Disease Models, Animal
- Immunity, Innate/immunology
- Macrophages/drug effects
- Macrophages/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myeloid Differentiation Factor 88
- Phagocytosis/drug effects
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Specific Pathogen-Free Organisms
- Toll-Like Receptor 2
- Toll-Like Receptor 4
- Uric Acid/immunology
- Uric Acid/toxicity
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Affiliation(s)
- Ru Liu-Bryan
- VA Medical Center, University of California, San Diego 92161, USA.
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Liu-Bryan R, Pay S, Schraufstatter IU, Rose DM. The CXCR1 tail mediates beta1 integrin-dependent cell migration via MAP kinase signaling. Biochem Biophys Res Commun 2005; 332:117-25. [PMID: 15896307 DOI: 10.1016/j.bbrc.2005.04.139] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Accepted: 04/27/2005] [Indexed: 10/25/2022]
Abstract
In this study, we examined how IL-8 induces leukocyte migration on major beta1 integrin ligands derived from the extracellular matrix protein fibronectin. We assessed individual contributions of signaling by IL-8 receptors by transfection of CXCR1 and CXCR2 into rat basophilic leukemia (RBL) cells and human monocytic THP-1 cells. CXCR1 expressing cells migrated on the fibronectin ligands for alpha4beta1 and alpha5beta1 integrins in response to IL-8, whereas CXCR2 expressing cells did not. RBL cells expressing the chimeric CXCR1 receptor containing the cytoplasmic tail of CXCR2 had greatly blunted migration, while cells expressing the CXCR2 chimera with the tail of CXCR1 had augmented migration. Last, inhibitors of p38 and JNK MAP kinases blocked IL-8-induced migration in CXCR1+ cells. We conclude that IL-8 stimulated beta1 integrin-mediated leukocyte migration on fibronectin through CXCR1 is dependent on the C-terminal cytoplasmic domain of CXCR1 and subsequent p38 and JNK MAPK signaling.
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Affiliation(s)
- Ru Liu-Bryan
- Department of Medicine, Veterans Affairs Medical Center, University of California, San Diego, CA, USA
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Liu-Bryan R, Pritzker K, Firestein GS, Terkeltaub R. TLR2 Signaling in Chondrocytes Drives Calcium Pyrophosphate Dihydrate and Monosodium Urate Crystal-Induced Nitric Oxide Generation. J Immunol 2005; 174:5016-23. [PMID: 15814732 DOI: 10.4049/jimmunol.174.8.5016] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Microcrystals of calcium pyrophosphate dihydrate (CPPD) and monosodium urate (MSU) deposited in synovium and articular cartilage initiate joint inflammation and cartilage degradation in large part by binding and directly activating resident cells. TLRs trigger innate host defense responses to infectious pathogens, and the expression of certain TLRs by synovial fibroblasts has revealed the potential for innate immune responses to be triggered by mesenchymally derived resident cells in the joint. In this study we tested the hypothesis that chondrocytes also express TLRs and that one or more TLRs centrally mediate chondrocyte responsiveness to CPPD and MSU crystals in vitro. We detected TLR2 expression in normal articular chondrocytes and up-regulation of TLR2 in osteoarthritic cartilage chondrocytes in situ. We demonstrated that transient transfection of TLR2 signaling-negative regulator Toll-interacting protein or treatment with TLR2-blocking Ab suppressed CPPD and MSU crystal-induced chondrocyte release of NO, an inflammatory mediator that promotes cartilage degeneration. Conversely, gain-of-function of TLR2 in normal chondrocytes via transfection was associated with increased CPPD and MSU crystal-induced NO release. Canonical TLR signaling by parallel pathways involving MyD88, IL-1R-associated kinase 1, TNF receptor-associated factor 6, and IkappaB kinase and Rac1, PI3K, and Akt critically mediated NO release in chondrocytes stimulated by both CPPD and MSU crystals. We conclude that CPPD and MSU crystals critically use TLR2-mediated signaling in chondrocytes to trigger NO generation. Our results indicate the potential for innate immunity at the level of the articular chondrocyte to directly contribute to inflammatory and degenerative tissue reactions associated with both gout and pseudogout.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Antigens, Differentiation/metabolism
- Base Sequence
- Calcium Pyrophosphate/metabolism
- Calcium Pyrophosphate/toxicity
- Cattle
- Cells, Cultured
- Chondrocalcinosis/etiology
- Chondrocalcinosis/immunology
- Chondrocalcinosis/metabolism
- Chondrocytes/drug effects
- Chondrocytes/immunology
- Chondrocytes/metabolism
- Crystallization
- DNA, Complementary/genetics
- Gene Expression
- Gout/etiology
- Gout/immunology
- Gout/metabolism
- Humans
- I-kappa B Kinase
- Immunity, Innate
- Interleukin-1 Receptor-Associated Kinases
- Membrane Glycoproteins/antagonists & inhibitors
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Models, Biological
- Myeloid Differentiation Factor 88
- Nitric Oxide/biosynthesis
- Phosphatidylinositol 3-Kinases/metabolism
- Protein Kinases/metabolism
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-akt
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cell Surface/antagonists & inhibitors
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Immunologic/metabolism
- Signal Transduction
- TNF Receptor-Associated Factor 6/metabolism
- Toll-Like Receptor 2
- Toll-Like Receptors
- Uric Acid/metabolism
- Uric Acid/toxicity
- rac1 GTP-Binding Protein/metabolism
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Affiliation(s)
- Ru Liu-Bryan
- Veterans Affairs Medical Center, San Diego, CA 92161, USA
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Cecil DL, Rose DM, Terkeltaub R, Liu-Bryan R. Role of interleukin-8 in PiT-1 expression and CXCR1-mediated inorganic phosphate uptake in chondrocytes. ACTA ACUST UNITED AC 2005; 52:144-54. [PMID: 15641067 DOI: 10.1002/art.20748] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The proinflammatory chemokine interleukin-8 (IL-8) induces chondrocyte hypertrophy. Moreover, chondrocyte hypertrophy develops in situ in osteoarthritic (OA) articular cartilage and promotes dysregulated matrix repair and calcification. Growth plate chondrocyte hypertrophy is associated with expression of the type III sodium-dependent inorganic phosphate (Pi) cotransporter phosphate transporter/retrovirus receptor 1 (PiT-1). This study was undertaken to test the hypothesis that IL-8 promotes chondrocyte hypertrophy by modulating chondrocyte PiT-1 expression and sodium-dependent Pi uptake, and to assess differential roles in this activity. METHODS The selective IL-8 receptor CXCR1 and the promiscuous chemokine receptor CXCR2 were used. Human knee OA cartilage, cultured normal bovine knee chondrocytes, and immortalized human articular chondrocytic CH-8 cells were transfected with CXCR1/CXCR2 chimeric receptors in which the 40-amino acid C-terminal cytosolic tail domains were swapped and site mutants of a CXCR1-specific region were generated. RESULTS Up-regulated PiT-1 expression was detected in OA cartilage. IL-8, but not IL-1 or the CXCR2 ligand growth-related oncogene alpha, induced PiT-1 expression and increased sodium-dependent Pi uptake by >40% in chondrocytes. The sodium/phosphate cotransport inhibitor phosphonoformic acid blocked IL-8-induced chondrocyte hypertrophic differentiation. Signaling mediated by kinase Pyk-2 was essential for IL-8 induction of PitT-1 expression and Pi uptake. Signaling through the TSYT(346-349) region of the CXCR1 cytosolic tail, a region divergent from the CXCR2 cytosolic tail, was essential for IL-8 to induce Pi uptake. CONCLUSION Our results link low-grade IL-8-mediated cartilaginous inflammation in OA to altered chondrocyte differentiation and disease progression through PiT-1 expression and sodium-dependent Pi uptake mediated by CXCR1 signaling.
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Affiliation(s)
- Denise L Cecil
- Veterans Affairs Medical Center, University of California-San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
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Tramontini N, Huber C, Liu-Bryan R, Terkeltaub RA, Kilgore KS. Central role of complement membrane attack complex in monosodium urate crystal-induced neutrophilic rabbit knee synovitis. ACTA ACUST UNITED AC 2004; 50:2633-9. [PMID: 15334478 DOI: 10.1002/art.20386] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Monosodium urate monohydrate (MSU) crystals promote gouty inflammation that is critically mediated by neutrophil recruitment and activation. Interleukin-8 (IL-8) and closely related chemokines are major neutrophil chemotaxins in experimental gout. But MSU crystals also activate the classical and alternative pathways of complement, and MSU crystals directly cleave C5 on the crystal surface. Unlike IL-8, the roles in acute gout of individual complement-derived peptides and of the terminal C5b-9 complement components that comprise the membrane attack complex (MAC) are unclear. Hence, we studied rabbits deficient in the MAC component C6 to determine if MAC mediated urate crystal-induced arthritis. METHODS We injected C6-deficient and C6-sufficient rabbit knee joints with 10 mg of pyrogen-free urate crystals and analyzed IL-8 levels, leukocyte influx, and joint inflammation 24 hours later. RESULTS There was a significant decrease (>60%) in swelling in MSU crystal-injected knees of C6-deficient animals as compared with C6-sufficient animals (P < 0.05). An attenuated rise in MSU crystal-induced joint effusion levels of IL-8 also was observed, which was concordant with diminished numbers of neutrophils (P < 0.05) but not monocytes in MSU crystal-induced knee synovial fluid from C6-deficient animals. Synovial tissue analysis confirmed mononuclear leukocyte infiltration in response to MSU crystal injection in all animals, but substantial neutrophil infiltration only in C6-sufficient animals. CONCLUSION MAC activation appears to play a major role in intraarticular IL-8 generation and in neutrophil recruitment in experimental acute gouty arthritis of the rabbit knee. C6 and MAC activation may represent novel therapeutic targets for suppression of neutrophil-mediated joint inflammation in gout.
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