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Liu Y, Jiang W, Huang J, Zhong L. Bioinformatic analysis combined with immune infiltration to explore osteoarthritis biomarkers and drug prediction. Medicine (Baltimore) 2024; 103:e38430. [PMID: 38905428 PMCID: PMC11191918 DOI: 10.1097/md.0000000000038430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 05/10/2024] [Indexed: 06/23/2024] Open
Abstract
Along with global aging, osteoarthritis (OA) appears to have a high incidence and disability rate, which seriously affects the quality of life of patients, making age a major risk factor. However, the pathology of OA is under-researched, and there is no obvious and effective treatment. Research has demonstrated the importance of aging, inflammation, and immunology in the onset and course of OA. This study aims to anticipate therapeutic drugs based on critical genes associated with OA and to elucidate the roles of genes and possible biomarkers associated with inflammation, immunology, and cellular senescence in OA. The OA gene expression matrix was first obtained from the Gene Expression Omnibus database. Screening for OA significant differentially expressed genes by bioinformatics identification. Specific biological processes and related signaling pathways of the differential genes were enriched. Then elucidate the status of immune cell involvement in OA based on immune infiltration analysis. Finally predict therapeutic agents based on pivotal genes. A total of 198 differentially expressed genes were identified in OA, and TP53, EGFR, TGFB1, LEP, CD4, MAPK8, SCARB1, ADIPOQ, JAK2, and SERPINE1 were further identified as important hub genes. The enrichment results showed that the development of arthritis was mainly related to immune cell differentiation, amino acid metabolism and cellular senescence process. The validation of immune infiltration results indicated that NK_cells, CD4_Tcells, Macrophages, Monocytic_lineage, Dendritic_cells, Basophils, CD8+_naive_T-cells may play an important role in the immune process of OA. Key Drug Prediction of Hub Genes found that Halicin, Ruxolitinib, Tofacitinib, Clenoliximab, Baricitinib may be a key drug or component in the treatment of OA.
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Affiliation(s)
- Yan Liu
- Gerontology Medicine Department, The Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
| | - Wei Jiang
- Rehabilitation Medicine Department, The Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
| | - Juan Huang
- Rehabilitation Medicine Department, The Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
| | - Li Zhong
- Gerontology Medicine Department, The Affiliated Hospital of Southwest Medical University, Southwest Medical University, Luzhou, China
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2
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Arnér ESJ, Schmidt EE. Unresolved questions regarding cellular cysteine sources and their possible relationships to ferroptosis. Adv Cancer Res 2024; 162:1-44. [PMID: 39069366 DOI: 10.1016/bs.acr.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Cysteine is required for synthesis of glutathione (GSH), coenzyme A, other sulfur-containing metabolites, and most proteins. In most cells, cysteine comes from extracellular disulfide sources including cystine, glutathione-disulfide, and peptides. The thioredoxin reductase-1 (TrxR1)- or glutathione-disulfide reductase (GSR)-driven enzymatic systems can fuel cystine reduction via thioredoxins, glutaredoxins, or other thioredoxin-fold proteins. Free cystine enters cells thorough the cystine-glutamate antiporter, xCT, but systemically, plasma glutathione-disulfide might predominate as a cystine source. Erastin, inhibiting both xCT and voltage-dependent anion channels, induces ferroptotic cell death, so named because this type of cell death is antagonized by iron-chelators. Many cancer cells seem to be predisposed to ferroptosis, which has been proposed as a targetable cancer liability. Ferroptosis is associated with lipid peroxidation and loss of either glutathione peroxidase-4 (GPX4) or ferroptosis suppressor protein-1 (FSP1), which each prevent accumulation of lipid peroxides. It has been suggested that an xCT inhibition-induced cellular cysteine-deficiency lowers GSH levels, starving GPX4 for reducing power and allowing membrane lipid peroxides to accumulate, thereby causing ferroptosis. Aspects of ferroptosis are however not fully understood and need to be further scrutinized, for example that neither disruption of GSH synthesis, loss of GSH, nor disruption of glutathione disulfide reductase (GSR), triggers ferroptosis in animal models. Here we reevaluate the relationships between Erastin, xCT, GPX4, cellular cysteine and GSH, RSL3 or ML162, and ferroptosis. We conclude that, whereas both Cys and ferroptosis are potential liabilities in cancer, their relationship to each other remains insufficiently understood.
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Affiliation(s)
- Elias S J Arnér
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institutes of Oncology, Budapest, Hungary
| | - Edward E Schmidt
- Laboratory of Redox Biology, University of Veterinary Medicine, Budapest, Hungary; Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States.
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3
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Ehlers L, Kuppe A, Damerau A, Wilantri S, Kirchner M, Mertins P, Strehl C, Buttgereit F, Gaber T. Surface AMP deaminase 2 as a novel regulator modifying extracellular adenine nucleotide metabolism. FASEB J 2021; 35:e21684. [PMID: 34159634 DOI: 10.1096/fj.202002658rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/06/2021] [Accepted: 05/06/2021] [Indexed: 12/16/2022]
Abstract
Adenine nucleotides represent crucial immunomodulators in the extracellular environment. The ectonucleotidases CD39 and CD73 are responsible for the sequential catabolism of ATP to adenosine via AMP, thus promoting an anti-inflammatory milieu induced by the "adenosine halo". AMPD2 intracellularly mediates AMP deamination to IMP, thereby both enhancing the degradation of inflammatory ATP and reducing the formation of anti-inflammatory adenosine. Here, we show that this enzyme is expressed on the surface of human immune cells and its predominance may modify inflammatory states by altering the extracellular milieu. Surface AMPD2 (eAMPD2) expression on monocytes was verified by immunoblot, surface biotinylation, mass spectrometry, and immunofluorescence microscopy. Flow cytometry revealed enhanced monocytic eAMPD2 expression after TLR stimulation. PBMCs from patients with rheumatoid arthritis displayed significantly higher levels of eAMPD2 expression compared with healthy controls. Furthermore, the product of AMPD2-IMP-exerted anti-inflammatory effects, while the levels of extracellular adenosine were not impaired by an increased eAMPD2 expression. In summary, our study identifies eAMPD2 as a novel regulator of the extracellular ATP-adenosine balance adding to the immunomodulatory CD39-CD73 system.
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Affiliation(s)
- Lisa Ehlers
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
| | - Aditi Kuppe
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
| | - Alexandra Damerau
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
| | - Siska Wilantri
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
| | - Marieluise Kirchner
- BIH Core Unit Proteomics, Berlin Institute of Health (BIH) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Philipp Mertins
- BIH Core Unit Proteomics, Berlin Institute of Health (BIH) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Cindy Strehl
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
| | - Frank Buttgereit
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
| | - Timo Gaber
- Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Deutsches Rheuma-Forschungszentrum (DRFZ) Institute of the Leibniz Association, Berlin, Germany
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4
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Tseng CC, Chen YJ, Chang WA, Tsai WC, Ou TT, Wu CC, Sung WY, Yen JH, Kuo PL. Dual Role of Chondrocytes in Rheumatoid Arthritis: The Chicken and the Egg. Int J Mol Sci 2020; 21:E1071. [PMID: 32041125 PMCID: PMC7038065 DOI: 10.3390/ijms21031071] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 12/22/2022] Open
Abstract
Rheumatoid arthritis (RA) is one of the inflammatory joint diseases that display features of articular cartilage destruction. The underlying disturbance results from immune dysregulation that directly and indirectly influence chondrocyte physiology. In the last years, significant evidence inferred from studies in vitro and in the animal model offered a more holistic vision of chondrocytes in RA. Chondrocytes, despite being one of injured cells in RA, also undergo molecular alterations to actively participate in inflammation and matrix destruction in the human rheumatoid joint. This review covers current knowledge about the specific cellular and biochemical mechanisms that account for the chondrocyte signatures of RA and its potential applications for diagnosis and prognosis in RA.
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Affiliation(s)
- Chia-Chun Tseng
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (C.-C.T.); (Y.-J.C.); (W.-A.C.)
- Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (W.-C.T.); (T.-T.O.); (C.-C.W.); (W.-Y.S.)
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (C.-C.T.); (Y.-J.C.); (W.-A.C.)
- Department of Physical Medicine and Rehabilitation, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Wei-An Chang
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (C.-C.T.); (Y.-J.C.); (W.-A.C.)
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Division of Pulmonary and Critical Care Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan
| | - Wen-Chan Tsai
- Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (W.-C.T.); (T.-T.O.); (C.-C.W.); (W.-Y.S.)
| | - Tsan-Teng Ou
- Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (W.-C.T.); (T.-T.O.); (C.-C.W.); (W.-Y.S.)
| | - Cheng-Chin Wu
- Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (W.-C.T.); (T.-T.O.); (C.-C.W.); (W.-Y.S.)
| | - Wan-Yu Sung
- Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (W.-C.T.); (T.-T.O.); (C.-C.W.); (W.-Y.S.)
| | - Jeng-Hsien Yen
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (C.-C.T.); (Y.-J.C.); (W.-A.C.)
- Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (W.-C.T.); (T.-T.O.); (C.-C.W.); (W.-Y.S.)
| | - Po-Lin Kuo
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (C.-C.T.); (Y.-J.C.); (W.-A.C.)
- Institute of Biomedical Science, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
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5
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Sanchez C, Bay-Jensen AC, Pap T, Dvir-Ginzberg M, Quasnichka H, Barrett-Jolley R, Mobasheri A, Henrotin Y. Chondrocyte secretome: a source of novel insights and exploratory biomarkers of osteoarthritis. Osteoarthritis Cartilage 2017; 25:1199-1209. [PMID: 28232143 DOI: 10.1016/j.joca.2017.02.797] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/31/2017] [Accepted: 02/14/2017] [Indexed: 02/02/2023]
Abstract
The extracellular matrix (ECM) of articular cartilage is comprised of complex networks of proteins and glycoproteins, all of which are expressed by its resident cell, the chondrocyte. Cartilage is a unique tissue given its complexity and ability to resist repeated load and deformation. The mechanisms by which articular cartilage maintains its integrity throughout our lifetime is not fully understood, however there are numerous regulatory pathways known to govern ECM turnover in response to mechanical stimuli. To further our understanding of this field, we envision that proteomic analysis of the secretome will provide information on how the chondrocyte remodels the surrounding ECM in response to load, in addition to providing information on the metabolic state of the cell. In this review, we attempt to summarize the recent mass spectrometry-based proteomic discoveries in healthy and diseased cartilage and chondrocytes, to facilitate the discovery of novel biomarkers linked to degenerative pathologies, such as osteoarthritis (OA).
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Affiliation(s)
- C Sanchez
- Bone and Cartilage Research Unit, Arthropôle Liège, University of Liège, CHU Sart-Tilman, Belgium; The D-BOARD European Consortium for Biomarker Discovery.
| | - A-C Bay-Jensen
- The D-BOARD European Consortium for Biomarker Discovery; Department of Rheumatology, Biomarkers and Research, Nordic Bioscience, Herlev Hovedgade 207, 2730, Herlev, Denmark.
| | - T Pap
- The D-BOARD European Consortium for Biomarker Discovery; Institute of Experimental Musculoskeletal Medicine, University Hospital Munster, Domagkstrasse 3, D-48149, Munster, Germany.
| | - M Dvir-Ginzberg
- The D-BOARD European Consortium for Biomarker Discovery; Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University of Jerusalem, P.O. Box 12272, Jerusalem, 91120, Israel.
| | - H Quasnichka
- The D-BOARD European Consortium for Biomarker Discovery; Department of Veterinary Pre-Clinical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, United Kingdom.
| | - R Barrett-Jolley
- The D-BOARD European Consortium for Biomarker Discovery; Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, Faculty of Health & Life Sciences, University of Liverpool, Liverpool, United Kingdom.
| | - A Mobasheri
- The D-BOARD European Consortium for Biomarker Discovery; Department of Veterinary Pre-Clinical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, United Kingdom; Faculty of Health and Medical Sciences, Duke of Kent Building, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom; Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom; Center of Excellence in Genomic Medicine Research (CEGMR), King Fahd Medical Research Center (KFMRC), Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
| | - Y Henrotin
- Bone and Cartilage Research Unit, Arthropôle Liège, University of Liège, CHU Sart-Tilman, Belgium; The D-BOARD European Consortium for Biomarker Discovery.
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Machida T, Nishida K, Nasu Y, Nakahara R, Ozawa M, Harada R, Horita M, Takeshita A, Kaneda D, Yoshida A, Ozaki T. Inhibitory effect of JAK inhibitor on mechanical stress-induced protease expression by human articular chondrocytes. Inflamm Res 2017; 66:999-1009. [PMID: 28752178 DOI: 10.1007/s00011-017-1083-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 07/17/2017] [Accepted: 07/20/2017] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To investigate whether janus kinase (JAK) inhibitor exhibits a chondro-protective effect against mechanical stress-induced expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) and matrix metalloproteinase (MMPs) in human chondrocytes. MATERIALS AND METHODS Normal human articular chondrocytes were seeded onto stretch chambers and incubated with or without tofacitinib (1000 nM) for 12 h before mechanical stimulation or cytokine stimulation. Uni-axial cyclic tensile strain (CTS) (0.5 Hz, 10% elongation, 30 min) was applied and the gene expression levels of type II collagen α1 chain (COL2A1), aggrecan (ACAN), ADAMTS4, ADAMTS5, MMP13, and runt-related transcription factor 2 (RUNX-2) were examined by real-time polymerase chain reaction. Nuclear translocation of RUNX-2 and nuclear factor-κB (NF-κB) was examined by immunocytochemistry, and phosphorylation of mitogen-activated protein kinase (MAPK) and signaling transducer and activator of transcription (STAT) 3 was examined by western blotting. The concentration of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α in the supernatant was examined by enzyme-linked immunosorbent assay. RESULTS COL2A1 and ACAN gene expression levels were decreased by CTS, but these catabolic effects were canceled by tofacitinib. Tofacitinib significantly down-regulated CTS-induced expression of ADAMTS4, ADAMTS5, MMP13, and RUNX2, and the release of IL-6 in supernatant by chondrocytes. Tofacitinib also reduced CTS-induced nuclear translocation of RUNX-2 and NF-κB, and phosphorylation of MAPK and STAT3. CONCLUSION Tofacitinib suppressed mechanical stress-induced expression of ADAMTS4, ADAMTS5, and MMP13 by human chondrocytes through inhibition of the JAK/STAT and MAPK cascades.
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Affiliation(s)
- Takahiro Machida
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Keiichiro Nishida
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan.
| | - Yoshihisa Nasu
- Department of Medical Materials for Musculoskeletal Reconstruction, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Ryuichi Nakahara
- Department of Musculoskeletal Traumatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Masatsugu Ozawa
- Department of Orthopaedic Surgery, Okayama City Hospital, 3-20-1 Kitanagaseomote-cho, Okayama, 700-8557, Japan
| | - Ryozo Harada
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Masahiro Horita
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Ayumu Takeshita
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Daisuke Kaneda
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Aki Yoshida
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Toshifumi Ozaki
- Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
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Hypoxia-induced production of peptidylarginine deiminases and citrullinated proteins in malignant glioma cells. Biochem Biophys Res Commun 2016; 482:50-56. [PMID: 27818200 DOI: 10.1016/j.bbrc.2016.10.154] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 10/25/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND Recently, it has been reported that hypoxia highly enhances expression of peptidylarginine deiminase (PAD) 4 and production of citrullinated proteins in some tumor cells. However, little is known about malignant gliomas on this issue. Therefore, we here investigated whether expression of PADs was induced by hypoxia and whether PADs citrullinated intracellular proteins if induced using U-251 MG cells of a human malignant glioma cell line. METHODS Expression of PADs in U-251 MG cells, cultured under hypoxia or normoxia for 24 h, was investigated by quantitative polymerase chain reaction (qPCR). Citrullination of proteins in the cells and the cell lysates incubated for 48 h with or without Ca2+ was detected by western blotting. Citrullinated proteins were identified by mass spectrometry. RESULTS The mRNA levels of PAD1, 2, 3, and 4 were up-regulated by hypoxia in a hypoxia-inducible factor-1-dependent manner in U-251 MG cells. In spite of the increased expression, intracellular proteins were not citrullinated. However, the induced PADs citrullinated U-251 MG cell-derived proteins when the cells were lysed. Multiple proteins citrullinated by hypoxia-induced PADs were identified. In addition, the extracellular domain of vascular endothelial growth factor receptor 2 was citrullinated by human PAD2 in vitro. CONCLUSION Our data may contribute to understanding of pathophysiology of malignant gliomas from the aspects of protein citrullination.
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Koizumi H, Arito M, Endo W, Kurokawa MS, Okamoto K, Omoteyama K, Suematsu N, Beppu M, Kato T. Effects of tofacitinib on nucleic acid metabolism in human articular chondrocytes. Mod Rheumatol 2015; 25:522-7. [PMID: 25496463 DOI: 10.3109/14397595.2014.995874] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE In our previous screening of chondrocyte protein profiles, the amount of adenosine monophosphate deaminase (AMPD) 2 was found to be decreased by tofacitinib. Extending the study, here we confirmed the decrease of AMPD2 by tofacitinib and further investigated effects of tofacitinib on purine nucleotide metabolism. METHODS Human articular chondrocytes and a chondrosarcoma cell line: OUMS-27 were stimulated with tofacitinib. Then the levels of AMPD2 and its related enzymes were investigated by Western blot. The levels of AMP and adenosine were assessed by mass spectrometry. RESULTS We confirmed the significant decrease of AMPD2 by tofacitinib in chondrocytes (p = 0.025). The levels of adenosine kinase and 5'-nucleotidase were decreased in chondrocytes, although they did not meet statistical significance (p = 0.067 and p = 0.074, respectively). The results from OUMS-27 were similar to those from the chondrocytes. The cellular adenosine levels were significantly decreased by tofacitinib in OUMS-27 (p = 0.014). The cellular AMP levels were increased, although they did not meet statistical significance in OUMS-27 (p = 0.066). CONCLUSION Our data indicate that tofacitinib increases the cellular levels of adenosine, which is known to have anti-inflammatory activity, through the downregulation of AMPD2. This would be a novel functional aspect of tofacitinib.
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Affiliation(s)
- Hideki Koizumi
- Clinical Proteomics & Molecular Medicine, St. Marianna University Graduate School of Medicine , Sugao, Miyamae, Kawasaki, Kanagawa , Japan
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