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Yu R, Han H, Chu S, Ding Y, Jin S, Wang Y, Jiang W, Liu Y, Zou Y, Wang M, Liu Q, Sun G, Jiang B, Gong Y. CUL4B orchestrates mesenchymal stem cell commitment by epigenetically repressing KLF4 and C/EBPδ. Bone Res 2023; 11:29. [PMID: 37268647 DOI: 10.1038/s41413-023-00263-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 03/23/2023] [Accepted: 04/04/2023] [Indexed: 06/04/2023] Open
Abstract
Dysregulated lineage commitment of mesenchymal stem cells (MSCs) contributes to impaired bone formation and an imbalance between adipogenesis and osteogenesis during skeletal aging and osteoporosis. The intrinsic cellular mechanism that regulates MSC commitment remains unclear. Here, we identified Cullin 4B (CUL4B) as a critical regulator of MSC commitment. CUL4B is expressed in bone marrow MSCs (BMSCs) and downregulated with aging in mice and humans. Conditional knockout of Cul4b in MSCs resulted in impaired postnatal skeletal development with low bone mass and reduced bone formation. Moreover, depletion of CUL4B in MSCs aggravated bone loss and marrow adipose accumulation during natural aging or after ovariectomy. In addition, CUL4B deficiency in MSCs reduced bone strength. Mechanistically, CUL4B promoted osteogenesis and inhibited adipogenesis of MSCs by repressing KLF4 and C/EBPδ expression, respectively. The CUL4B complex directly bound to Klf4 and Cebpd and epigenetically repressed their transcription. Collectively, this study reveals CUL4B-mediated epigenetic regulation of the osteogenic or adipogenic commitment of MSCs, which has therapeutic implications in osteoporosis.
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Affiliation(s)
- Ruiqi Yu
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Hong Han
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Shuxian Chu
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Yijun Ding
- The Key Laboratory of Liquid‒Solid Structural Evolution and Processing of Materials of Ministry of Education and Institute of Liquid Metal and Casting Technology, School of Materials Science and Engineering, Shandong University, Jinan, 250012, China
| | - Shiqi Jin
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Yufeng Wang
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Wei Jiang
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Yuting Liu
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Yongxin Zou
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Molin Wang
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Qiao Liu
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Gongping Sun
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Histology and Embryology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China
| | - Baichun Jiang
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China.
| | - Yaoqin Gong
- The Key Laboratory of Experimental Teratology of the Ministry of Education and Department of Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China.
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Rumman M, Dhawan J. PTPRU, a quiescence-induced receptor tyrosine phosphatase negatively regulates osteogenic differentiation of human mesenchymal stem cells. Biochem Biophys Res Commun 2022; 636:41-49. [DOI: 10.1016/j.bbrc.2022.10.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/18/2022] [Indexed: 11/02/2022]
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3
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Olson N, Gularte-Mérida R, Selenica P, Da Cruz Paula A, Alemar B, Weigelt B, Lefferts J, Linos K. Molecular Characterization of a Rare Dedifferentiated Liposarcoma With Rhabdomyosarcomatous Differentiation in a 24 Year Old. Int J Surg Pathol 2019; 28:454-463. [PMID: 31801397 PMCID: PMC8302235 DOI: 10.1177/1066896919890401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Aims. The aim of this study was to identify potential driver genetic alterations in a dedifferentiated liposarcoma (DDLPS) with rhabdomyosarcomatous differentiation. Methods and Results. A 24-year-old female underwent resection of an abdominal mass, which on a previous biopsy demonstrated rhabdomyosarcomatous differentiation concerning for embryonal rhabdomyosarcoma. Histologically the resected tumor displayed a high-grade sarcoma with rhabdomyosarcomatous differentiation in the background of well-differentiated liposarcoma consistent with DDLPS. Fluorescence in situ hybridization confirmed MDM2 amplification, as did array-based copy number profiling. Whole-exome sequencing revealed a somatic FGFR1 hotspot mutation and RNA sequencing an LMNB2-MAP2K6 fusion only within the dedifferentiated component. Conclusions. This study represents an in-depth examination of a rare DDLPS with rhabdomyosarcomatous differentiation in a young individual. Additionally, it is also instructive of a potential pitfall when assessing for MDM2 amplification in small biopsies. Despite exhaustive analysis, mutation and gene copy number analysis did not identify any molecular events that would underlie the rhabdomyoblastic differentiation. Our understanding of what causes some tumors to dedifferentiate as well as undergo divergent differentiation is limited, and larger studies are needed.
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Affiliation(s)
- Nicholas Olson
- Dartmouth-Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, USA
| | | | - Pier Selenica
- Memorial Sloan Kettering Cancer Center, New York, NY, USA.,University of Maastricht, Maastricht, Netherlands
| | | | - Barbara Alemar
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Britta Weigelt
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Joel Lefferts
- Dartmouth-Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, USA
| | - Konstantinos Linos
- Dartmouth-Hitchcock Medical Center and Geisel School of Medicine, Lebanon, NH, USA
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4
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PTPN21 Overexpression Promotes Osteogenic and Adipogenic Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells but Inhibits the Immunosuppressive Function. Stem Cells Int 2019; 2019:4686132. [PMID: 31885609 PMCID: PMC6907062 DOI: 10.1155/2019/4686132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 08/05/2019] [Accepted: 10/04/2019] [Indexed: 12/18/2022] Open
Abstract
Protein tyrosine phosphatases (PTPs) act as key regulators in various cellular processes such as proliferation, differentiation, and migration. Our previous research demonstrated that non-receptor-typed PTP21 (PTPN21), a member of the PTP family, played a critical role in the proliferation, cell cycle, and chemosensitivity of acute lymphoblastic leukemia cells. However, the role of PTPN21 in the bone marrow microenvironment has not yet been elucidated. In the study, we explored the effects of PTPN21 on human bone marrow-derived mesenchymal stem cells (BM-MSCs) via lentiviral-mediated overexpression and knock-down of PTPN21 in vitro. Overexpressing PTPN21 in BM-MSCs inhibited the proliferation through arresting cell cycle at the G0 phase but rendered them a higher osteogenic and adipogenic differentiation potential. In addition, overexpressing PTPN21 in BM-MSCs increased their senescence levels through upregulation of P21 and P53 and dramatically changed the levels of crosstalk with their typical target cells including immunocytes, tumor cells, and vascular endothelial cells. BM-MSCs overexpressing PTPN21 had an impaired immunosuppressive function and an increased capacity of recruiting tumor cells and vascular endothelial cells in a chemotaxis transwell coculture system. Collectively, our data suggested that PTPN21 acted as a pleiotropic factor in modulating the function of human BM-MSCs.
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Abstract
Adipocytic neoplasms include a diversity of both benign tumors (lipomas) and malignancies (liposarcomas), and each tumor type is characterized by its own unique molecular alterations driving tumorigenesis. Work over the past 30 years has established the diagnostic utility of several of these characteristic molecular alterations (e.g. MDM2 amplification in well- and dedifferentiated liposarcoma, FUS/EWSR1-DDIT3 gene fusions in myxoid liposarcoma, RB1 loss in spindle cell/pleomorphic lipoma). More recent studies have focused on additional molecular alterations which may have therapeutic or prognostic impact. This review will summarize several of the important molecular findings in adipocytic tumors that have been described over the past 10 years.
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Affiliation(s)
- Elizabeth G Demicco
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
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6
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Comprehensive and Integrated Genomic Characterization of Adult Soft Tissue Sarcomas. Cell 2017; 171:950-965.e28. [PMID: 29100075 DOI: 10.1016/j.cell.2017.10.014] [Citation(s) in RCA: 663] [Impact Index Per Article: 94.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 07/07/2017] [Accepted: 10/05/2017] [Indexed: 12/26/2022]
Abstract
Sarcomas are a broad family of mesenchymal malignancies exhibiting remarkable histologic diversity. We describe the multi-platform molecular landscape of 206 adult soft tissue sarcomas representing 6 major types. Along with novel insights into the biology of individual sarcoma types, we report three overarching findings: (1) unlike most epithelial malignancies, these sarcomas (excepting synovial sarcoma) are characterized predominantly by copy-number changes, with low mutational loads and only a few genes (TP53, ATRX, RB1) highly recurrently mutated across sarcoma types; (2) within sarcoma types, genomic and regulomic diversity of driver pathways defines molecular subtypes associated with patient outcome; and (3) the immune microenvironment, inferred from DNA methylation and mRNA profiles, associates with outcome and may inform clinical trials of immune checkpoint inhibitors. Overall, this large-scale analysis reveals previously unappreciated sarcoma-type-specific changes in copy number, methylation, RNA, and protein, providing insights into refining sarcoma therapy and relationships to other cancer types.
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Davies SJ, Ryan J, O'Connor PBF, Kenny E, Morris D, Baranov PV, O'Connor R, McCarthy TV. Itm2a silencing rescues lamin A mediated inhibition of 3T3-L1 adipocyte differentiation. Adipocyte 2017; 6:259-276. [PMID: 28872940 DOI: 10.1080/21623945.2017.1362510] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Dysregulation of adipose tissue metabolism is associated with multiple metabolic disorders. One such disease, known as Dunnigan-type familial partial lipodystrophy (FPLD2) is characterized by defective fat metabolism and storage. FPLD2 is caused by a specific subset of mutations in the LMNA gene. The mechanisms by which LMNA mutations lead to the adipose specific FPLD2 phenotype have yet to be determined in detail. We used RNA-Seq analysis to assess the effects of wild-type (WT) and mutant (R482W) lamin A on the expression profile of differentiating 3T3-L1 mouse preadipocytes and identified Itm2a as a gene that was upregulated at 36 h post differentiation induction in these cells. In this study we identify Itm2a as a novel modulator of adipogenesis and show that endogenous Itm2a expression is transiently downregulated during induction of 3T3-L1 differentiation. Itm2a overexpression was seen to moderately inhibit differentiation of 3T3-L1 preadipocytes while shRNA mediated knockdown of Itm2a significantly enhanced 3T3-L1 differentiation. Investigation of PPARγ levels indicate that this enhanced adipogenesis is mediated through the stabilization of the PPARγ protein at specific time points during differentiation. Finally, we demonstrate that Itm2a knockdown is sufficient to rescue the inhibitory effects of lamin A WT and R482W mutant overexpression on 3T3-L1 differentiation. This suggests that targeting of Itm2a or its related pathways, including autophagy, may have potential as a therapy for FPLD2.
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Affiliation(s)
- Stephanie J. Davies
- School of Biochemistry and Cell Biology, University College Cork, Co. Cork, Ireland
| | - James Ryan
- Mater Private Hospital, Citygate, Mahon, Cork, Ireland
| | | | - Elaine Kenny
- Neuropsychiatric Genetics Research Group, Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Dublin, Ireland
| | - Derek Morris
- Department of Biochemistry, National University of Ireland Galway, Galway, Ireland
| | - Pavel V. Baranov
- School of Biochemistry and Cell Biology, University College Cork, Co. Cork, Ireland
| | - Rosemary O'Connor
- School of Biochemistry and Cell Biology, University College Cork, Co. Cork, Ireland
| | - Tommie V. McCarthy
- School of Biochemistry and Cell Biology, University College Cork, Co. Cork, Ireland
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Recent advances in understanding the role of protein-tyrosine phosphatases in development and disease. Dev Biol 2017; 428:283-292. [PMID: 28728679 DOI: 10.1016/j.ydbio.2017.03.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 01/15/2023]
Abstract
Protein-tyrosine phosphatases (PTPs) remove phosphate groups from tyrosine residues, and thereby propagate or inhibit signal transduction, and hence influence cellular processes such as cell proliferation and differentiation. The importance of tightly controlled PTP activity is reflected by the numerous mechanisms employed by the cell to control PTP activity, including a variety of post-translational modifications, and restricted subcellular localization. This review highlights the strides made in the last decade and discusses the important role of PTPs in key aspects of embryonic development: the regulation of stem cell self-renewal and differentiation, gastrulation and somitogenesis during early embryonic development, osteogenesis, and angiogenesis. The tentative importance of PTPs in these processes is highlighted by the diseases that present upon aberrant activity.
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Kim EY, Kim WK, Oh KJ, Han BS, Lee SC, Bae KH. Recent advances in proteomic studies of adipose tissues and adipocytes. Int J Mol Sci 2015; 16:4581-99. [PMID: 25734986 PMCID: PMC4394436 DOI: 10.3390/ijms16034581] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 12/29/2014] [Accepted: 02/16/2015] [Indexed: 12/27/2022] Open
Abstract
Obesity is a chronic disease that is associated with significantly increased levels of risk of a number of metabolic disorders. Despite these enhanced health risks, the worldwide prevalence of obesity has increased dramatically over the past few decades. Obesity is caused by the accumulation of an abnormal amount of body fat in adipose tissue, which is composed mostly of adipocytes. Thus, a deeper understanding of the regulation mechanism of adipose tissue and/or adipocytes can provide a clue for overcoming obesity-related metabolic diseases. In this review, we describe recent advances in the study of adipose tissue and/or adipocytes, focusing on proteomic approaches. In addition, we suggest future research directions for proteomic studies which may lead to novel treatments of obesity and obesity-related diseases.
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Affiliation(s)
- Eun Young Kim
- Functional Genomics Research Center, KRIBB, Daejeon 305-806, Korea.
| | - Won Kon Kim
- Functional Genomics Research Center, KRIBB, Daejeon 305-806, Korea.
- Department of Functional Genomics, University of Science and Technology of Korea, Daejeon 305-806, Korea.
| | - Kyoung-Jin Oh
- Functional Genomics Research Center, KRIBB, Daejeon 305-806, Korea.
| | - Baek Soo Han
- Functional Genomics Research Center, KRIBB, Daejeon 305-806, Korea.
- Department of Functional Genomics, University of Science and Technology of Korea, Daejeon 305-806, Korea.
| | - Sang Chul Lee
- Functional Genomics Research Center, KRIBB, Daejeon 305-806, Korea.
- Department of Functional Genomics, University of Science and Technology of Korea, Daejeon 305-806, Korea.
| | - Kwang-Hee Bae
- Functional Genomics Research Center, KRIBB, Daejeon 305-806, Korea.
- Department of Functional Genomics, University of Science and Technology of Korea, Daejeon 305-806, Korea.
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10
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Lee Y, Song YS, Fang CH, So BI, Park JY, Joo HW, Park IH, Shen GY, Shin JH, Kim H, Ahn YH, Kim KS. Anti-obesity effects of granulocyte-colony stimulating factor in Otsuka-Long-Evans-Tokushima fatty rats. PLoS One 2014; 9:e105603. [PMID: 25144367 PMCID: PMC4140798 DOI: 10.1371/journal.pone.0105603] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 07/26/2014] [Indexed: 11/18/2022] Open
Abstract
Granulocyte-colony stimulating factor (G-CSF) has molecular structures and intracellular signaling pathways that are similar to those of leptin and ciliary neurotropic factor (CNTF). It also has immune-modulatory properties. Given that leptin and CNTF play important roles in energy homeostasis and that obesity is an inflammatory condition in adipose tissue, we hypothesized that G-CSF could also play a role in energy homeostasis. We treated 12 38-week-old male Otsuka-Long-Evans-Tokushima fatty rats (OLETF, diabetic) and 12 age-matched male Long-Evans-Tokushima rats (LETO, healthy) with 200 µg/day G-CSF or saline for 5 consecutive days. Body weight reduction was greater in G-CSF-treated OLETF (G-CSF/OLETF) than saline-treated OLETF (saline/OLETF) following 8 weeks of treatment (−6.9±1.6% vs. −3.1±2.2%, p<0.05). G-CSF treatment had no effect on body weight in LETO or on food intake in either OLETF or LETO. Body fat in G-CSF/OLETF was more reduced than in saline/OLETF (−32.2±3.1% vs. −20.8±6.2%, p<0.05). Energy expenditure was higher in G-CSF/OLETF from 4 weeks after the treatments than in saline/OLETF. Serum levels of cholesterol, triglyceride, interleukin-6 and tumor necrosis factor-α were lower in G-CSF/OLETF than in saline/OLETF. Uncoupling protein-1 (UCP-1) expression in brown adipose tissue (BAT) was higher in G-CSF/OLETF than in saline/OLETF, but was unaffected in LETO. Immunofluorescence staining and PCR results revealed that G-CSF receptors were expressed in BAT. In vitro experiments using brown adipocyte primary culture revealed that G-CSF enhanced UCP-1 expression from mature brown adipocytes via p38 mitogen-activated protein kinase pathway. In conclusion, G-CSF treatment reduced body weight and increased energy expenditure in a diabetic model, and enhanced UCP-1 expression and decreased inflammatory cytokine levels may be associated with the effects of G-CSF treatment.
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Affiliation(s)
- Yonggu Lee
- Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
- Department of Cardiology, Sung-Ae Hospital, Seoul, South Korea
| | - Yi-Sun Song
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Cheng-Hu Fang
- Division of Cardiology, Yanbian University, Yanji, China
| | - Byung-Im So
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Jun-Young Park
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Hyun-Woo Joo
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - In-Hwa Park
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Guang-Yin Shen
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
| | - Jeong-Hun Shin
- Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Hyuck Kim
- Department of Thoracic Surgery, Hanyang University Hospital, Seoul, South Korea
| | - You-Heon Ahn
- Department of Endocrinology, Hanyang University Hospital, Seoul, South Korea
| | - Kyung-Soo Kim
- Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, South Korea
- * E-mail:
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Choi HR, Kim WK, Park A, Jung H, Han BS, Lee SC, Bae KH. Protein tyrosine phosphatase profiling studies during brown adipogenic differentiation of mouse primary brown preadipocytes. BMB Rep 2014; 46:539-43. [PMID: 24152912 PMCID: PMC4133841 DOI: 10.5483/bmbrep.2013.46.11.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 03/16/2013] [Accepted: 03/31/2013] [Indexed: 11/20/2022] Open
Abstract
There is a correlation between obesity and the amount of brown adipose tissue; however, the molecular mechanism of brown adipogenic differentiation has not been as extensively studied. In this study, we performed a protein tyrosine phosphatase (PTP) profiling analysis during the brown adipogenic differentiation of mouse primary brown preadipocytes. Several PTPs, including PTPRF, PTPRZ, and DUSP12 showing differential expression patterns were identified. In the case of DUSP12, the expression level is dramatically downregulated during brown adipogenesis. The ectopic expression of DUSP12 using a retroviral expression system induces the suppression of adipogenic differentiation, whereas a catalytic inactive DUSP12 mutant showed no effect on differentiation. These results suggest that DUSP12 is involved in brown adipogenic differentiation and may be used as a target protein for the treatment or prevention of obesity by the regulation of brown adipogenic differentiation.
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Affiliation(s)
- Hye-Ryung Choi
- Research Center for Integrated Cellulomics, KRIBB; Department of Functional Genomics, University of Science and Technology (UST), Daejeon 305-806, Korea
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12
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Kim EY, Kim JW, Kim WK, Han BS, Park SG, Chung BH, Lee SC, Bae KH. Selection of aptamers for mature white adipocytes by cell SELEX using flow cytometry. PLoS One 2014; 9:e97747. [PMID: 24844710 PMCID: PMC4028271 DOI: 10.1371/journal.pone.0097747] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/23/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Adipose tissue, mainly composed of adipocytes, plays an important role in metabolism by regulating energy homeostasis. Obesity is primarily caused by an abundance of adipose tissue. Therefore, specific targeting of adipose tissue is critical during the treatment of obesity, and plays a major role in overcoming it. However, the knowledge of cell-surface markers specific to adipocytes is limited. METHODS AND RESULTS We applied the CELL SELEX (Systematic Evolution of Ligands by EXponential enrichment) method using flow cytometry to isolate molecular probes for specific recognition of adipocytes. The aptamer library, a mixture of FITC-tagged single-stranded random DNAs, is used as a source for acquiring molecular probes. With the increasing number of selection cycles, there was a steady increase in the fluorescence intensity toward mature adipocytes. Through 12 rounds of SELEX, enriched aptamers showing specific recognition toward mature 3T3-L1 adipocyte cells were isolated. Among these, two aptamers (MA-33 and 91) were able to selectively bind to mature adipocytes with an equilibrium dissociation constant (Kd) in the nanomolar range. These aptamers did not bind to preadipocytes or other cell lines (such as HeLa, HEK-293, or C2C12 cells). Additionally, it was confirmed that MA-33 and 91 can distinguish between mature primary white and primary brown adipocytes. CONCLUSIONS These selected aptamers have the potential to be applied as markers for detecting mature white adipocytes and monitoring adipogenesis, and could emerge as an important tool in the treatment of obesity.
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Affiliation(s)
- Eun Young Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Ji Won Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
| | - Won Kon Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Baek Soo Han
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Sung Goo Park
- Medical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Bong Hyun Chung
- BioNanotechnology Research Center, Bioconvergence Research Institute, KRIBB, Daejeon, Republic of Korea
| | - Sang Chul Lee
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
| | - Kwang-Hee Bae
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
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13
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Egan JB, Barrett MT, Champion MD, Middha S, Lenkiewicz E, Evers L, Francis P, Schmidt J, Shi CX, Van Wier S, Badar S, Ahmann G, Kortuem KM, Boczek NJ, Fonseca R, Craig DW, Carpten JD, Borad MJ, Stewart AK. Whole genome analyses of a well-differentiated liposarcoma reveals novel SYT1 and DDR2 rearrangements. PLoS One 2014; 9:e87113. [PMID: 24505276 PMCID: PMC3914808 DOI: 10.1371/journal.pone.0087113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 12/22/2013] [Indexed: 12/30/2022] Open
Abstract
Liposarcoma is the most common soft tissue sarcoma, but little is known about the genomic basis of this disease. Given the low cell content of this tumor type, we utilized flow cytometry to isolate the diploid normal and aneuploid tumor populations from a well-differentiated liposarcoma prior to array comparative genomic hybridization and whole genome sequencing. This work revealed massive highly focal amplifications throughout the aneuploid tumor genome including MDM2, a gene that has previously been found to be amplified in well-differentiated liposarcoma. Structural analysis revealed massive rearrangement of chromosome 12 and 11 gene fusions, some of which may be part of double minute chromosomes commonly present in well-differentiated liposarcoma. We identified a hotspot of genomic instability localized to a region of chromosome 12 that includes a highly conserved, putative L1 retrotransposon element, LOC100507498 which resides within a gene cluster (NAV3, SYT1, PAWR) where 6 of the 11 fusion events occurred. Interestingly, a potential gene fusion was also identified in amplified DDR2, which is a potential therapeutic target of kinase inhibitors such as dastinib, that are not routinely used in the treatment of patients with liposarcoma. Furthermore, 7 somatic, damaging single nucleotide variants have also been identified, including D125N in the PTPRQ protein. In conclusion, this work is the first to report the entire genome of a well-differentiated liposarcoma with novel chromosomal rearrangements associated with amplification of therapeutically targetable genes such as MDM2 and DDR2.
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Affiliation(s)
- Jan B. Egan
- Comprehensive Cancer Center, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Michael T. Barrett
- Clinical Translational Research Division, Translational Genomics Research Institute, Phoenix, Arizona, United States of America
| | - Mia D. Champion
- Department of Biomedical Statistics and Informatics, Mayo Clinic, Scottsdale, Arizona, United States of America
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Sumit Middha
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Elizabeth Lenkiewicz
- Clinical Translational Research Division, Translational Genomics Research Institute, Phoenix, Arizona, United States of America
| | - Lisa Evers
- Clinical Translational Research Division, Translational Genomics Research Institute, Phoenix, Arizona, United States of America
| | - Princy Francis
- Research, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Jessica Schmidt
- Research, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Chang-Xin Shi
- Research, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Scott Van Wier
- Research, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Sandra Badar
- Research, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Gregory Ahmann
- Research, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - K. Martin Kortuem
- Hematology, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Nicole J. Boczek
- Mayo Graduate School, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Rafael Fonseca
- Comprehensive Cancer Center, Mayo Clinic, Scottsdale, Arizona, United States of America
- Division of Hematology/Oncology Mayo Clinic, Scottsdale, Arizona, United States of America
| | - David W. Craig
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, Arizona, United States of America
| | - John D. Carpten
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, Arizona, United States of America
| | - Mitesh J. Borad
- Comprehensive Cancer Center, Mayo Clinic, Scottsdale, Arizona, United States of America
- Division of Hematology/Oncology Mayo Clinic, Scottsdale, Arizona, United States of America
| | - A. Keith Stewart
- Comprehensive Cancer Center, Mayo Clinic, Scottsdale, Arizona, United States of America
- Division of Hematology/Oncology Mayo Clinic, Scottsdale, Arizona, United States of America
- * E-mail:
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14
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Park H, Yu KR, Ku B, Kim BY, Kim SJ. Identification of novel PTPRQ phosphatase inhibitors based on the virtual screening with docking simulations. Theor Biol Med Model 2013; 10:49. [PMID: 23981594 PMCID: PMC3765866 DOI: 10.1186/1742-4682-10-49] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 08/23/2013] [Indexed: 02/05/2023] Open
Abstract
Protein tyrosine phosphatase receptor type Q (PTPRQ) is an unusual PTP that has intrinsic dephosphorylating activity for various phosphatidyl inositides instead of phospho-tyrosine substrates. Although PTPRQ was known to be involved in the pathogenesis of obesity, no small-molecule inhibitor has been reported so far. Here we report six novel PTPRQ inhibitors identified with computer-aided drug design protocol involving the virtual screening with docking simulations and enzyme inhibition assay. These inhibitors exhibit moderate potencies against PTPRQ with the associated IC50 values ranging from 29 to 86 μM. Because the newly discovered inhibitors were also computationally screened for having desirable physicochemical properties as a drug candidate, they deserve consideration for further development by structure-activity relationship studies to optimize the antiobestic activities. Structural features relevant to the stabilization of the inhibitors in the active site of PTPRQ are addressed in detail.
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Affiliation(s)
- Hwangseo Park
- Department of Bioscience and Biotechnology, Sejong University, 98 Kunja-Dong, Kwangjin-Ku, Seoul 143-747, Korea.
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15
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Choi HR, Kim WK, Kim EY, Han BS, Min JK, Chi SW, Park SG, Bae KH, Lee SC. Dual-specificity phosphatase 10 controls brown adipocyte differentiation by modulating the phosphorylation of p38 mitogen-activated protein kinase. PLoS One 2013; 8:e72340. [PMID: 23977283 PMCID: PMC3748012 DOI: 10.1371/journal.pone.0072340] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/09/2013] [Indexed: 11/23/2022] Open
Abstract
Background Brown adipocytes play an important role in regulating the balance of energy, and as such, there is a strong correlation between obesity and the amount of brown adipose tissue. Although the molecular mechanism underlying white adipocyte differentiation has been well characterized, brown adipocyte differentiation has not been studied extensively. Here, we investigate the potential role of dual-specificity phosphatase 10 (DUSP10) in brown adipocyte differentiation using primary brown preadipocytes. Methods and Results The expression of DUSP10 increased continuously after the brown adipocyte differentiation of mouse primary brown preadipocytes, whereas the phosphorylation of p38 was significantly upregulated at an early stage of differentiation followed by steep downregulation. The overexpression of DUSP10 induced a decrease in the level of p38 phosphorylation, resulting in lower lipid accumulation than that in cells overexpressing the inactive mutant DUSP10. The expression levels of several brown adipocyte markers such as PGC-1α, UCP1, and PRDM16 were also significantly reduced upon the ectopic expression of DUSP10. Furthermore, decreased mitochondrial DNA content was detected in cells expressing DUSP10. The results obtained upon treatment with the p38 inhibitor, SB203580, clearly indicated that the phosphorylation of p38 at an early stage is important in brown adipocyte differentiation. The effect of the p38 inhibitor was partially recovered by DUSP10 knockdown using RNAi. Conclusions These results suggest that p38 phosphorylation is controlled by DUSP10 expression. Furthermore, p38 phosphorylation at an early stage is critical in brown adipocyte differentiation. Thus, the regulation of DUSP10 activity affects the efficiency of brown adipogenesis. Consequently, DUSP10 can be used as a novel target protein for the regulation of obesity.
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Affiliation(s)
- Hye-Ryung Choi
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Won Kon Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Eun Young Kim
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
| | - Baek Soo Han
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
| | - Jeong-Ki Min
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
| | - Seung-Wook Chi
- Biomedical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Sung Goo Park
- Biomedical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Kwang-Hee Bae
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
- * E-mail: (KHB); (SCL)
| | - Sang Chul Lee
- Research Center for Integrated Cellulomics, KRIBB, Daejeon, Republic of Korea
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon, Republic of Korea
- * E-mail: (KHB); (SCL)
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16
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Pulido R, Stoker AW, Hendriks WJAJ. PTPs emerge as PIPs: protein tyrosine phosphatases with lipid-phosphatase activities in human disease. Hum Mol Genet 2013; 22:R66-76. [PMID: 23900072 DOI: 10.1093/hmg/ddt347] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Protein tyrosine phosphatases (PTPs) constitute a family of key homeostatic regulators, with wide implications on physiology and disease. Recent findings have unveiled that the biological activity of PTPs goes beyond the dephosphorylation of phospho-proteins to shut down protein tyrosine kinase-driven signaling cascades. Substrates dephosphorylated by clinically relevant PTPs extend to phospholipids and phosphorylated carbohydrates as well. In addition, non-catalytic functions are also used by PTPs to regulate essential cellular functions. Consequently, PTPs have emerged as novel potential therapeutic targets for human diseases, including cancer predispositions, myopathies and neuropathies. In this review, we highlight recent advances on the multifaceted role of lipid-phosphatase PTPs in human pathology, with an emphasis on hereditary diseases. The involved PTP regulatory networks and PTP modulatory strategies with potential therapeutic application are discussed.
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17
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Bae KH, Kim WK, Lee SC. Involvement of protein tyrosine phosphatases in adipogenesis: new anti-obesity targets? BMB Rep 2013; 45:700-6. [PMID: 23261055 PMCID: PMC4133817 DOI: 10.5483/bmbrep.2012.45.12.235] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Obesity is a worldwide epidemic as well as being a major risk factor for diabetes, cardiovascular diseases and several types of cancers. Obesity is mainly due to the overgrowth of adipose tissue arising from an imbalance between energy intake and energy expenditure. Adipose tissue, primarily composed of adipocytes, plays a key role in maintaining whole body energy homeostasis. In view of the treatment of obesity and obesity-related diseases, it is critical to understand the detailed signal transduction mechanisms of adipogenic differentiation. Adipogenic differentiation is tightly regulated by many key signal cascades, including insulin signaling. These signal cascades generally transfer or amplify the signal by using serial tyrosine phosphorylations. Thus, protein tyrosine kinases and protein tyrosine phosphatases are closely related to adipogenic differentiation. Compared to protein tyrosine kinases, protein tyrosine phosphatases have received little attention in adipogenic differentiation. This review aims to highlight the involvement of protein tyrosine phosphatases in adipogenic differentiation and the possibility of protein tyrosine phosphatases as drugs to target obesity. [BMB Reports 2012; 45(12): 700-706]
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Affiliation(s)
- Kwang-Hee Bae
- Medical Proteomics Research Center, KRIBB, Daejeon 305-806, Korea.
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18
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Faça VM. Human mesenchymal stromal cell proteomics: contribution for identification of new markers and targets for medicine intervention. Expert Rev Proteomics 2012; 9:217-30. [PMID: 22462791 DOI: 10.1586/epr.12.9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mesenchymal stem or stromal cells (MSCs) have become of great interest for cell-based therapy owing to their roles in tissue repair and immune suppression. MSCs have the ability to differentiate into specialized tissues, including bone, cartilage and muscle, among several others. Furthermore, it has been found that MSCs can also serve as cellular factories that secrete mediators to stimulate in situ regeneration of injured tissues. Proteomics has contributed significantly to the identification of new proteins to improve cellular characterization of MSCs, to identify new targets for therapeutic intervention and to elucidate important pathways utilized by MSCs to differentiate into distinct tissues. As proteomics technology advances, several studies can be revisited and analyzed in depth, employing state-of-the-art approaches, helping to uncover the cellular mechanisms utilized by MSCs to exert their regenerative functionalities. In this article, we will review the progress made so far and discuss further opportunities for proteomics to contribute to the clinical applications of MSCs.
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Affiliation(s)
- Vitor Marcel Faça
- Department of Biochemistry & Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
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19
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Kim EY, Kim WK, Kang HJ, Kim JH, Chung SJ, Seo YS, Park SG, Lee SC, Bae KH. Acetylation of malate dehydrogenase 1 promotes adipogenic differentiation via activating its enzymatic activity. J Lipid Res 2012; 53:1864-76. [PMID: 22693256 DOI: 10.1194/jlr.m026567] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Acetylation is one of the most crucial post-translational modifications that affect protein function. Protein lysine acetylation is catalyzed by acetyltransferases, and acetyl-CoA functions as the source of the acetyl group. Additionally, acetyl-CoA plays critical roles in maintaining the balance between carbohydrate metabolism and fatty acid synthesis. Here, we sought to determine whether lysine acetylation is an important process for adipocyte differentiation. Based on an analysis of the acetylome during adipogenesis, various proteins displaying significant quantitative changes were identified by LC-MS/MS. Of these identified proteins, we focused on malate dehydrogenase 1 (MDH1). The acetylation level of MDH1 was increased up to 6-fold at the late stage of adipogenesis. Moreover, overexpression of MDH1 in 3T3-L1 preadipocytes induced a significant increase in the number of cells undergoing adipogenesis. The introduction of mutations to putative lysine acetylation sites showed a significant loss of the ability of cells to undergo adipogenic differentiation. Furthermore, the acetylation of MDH1 dramatically enhanced its enzymatic activity and subsequently increased the intracellular levels of NADPH. These results clearly suggest that adipogenic differentiation may be regulated by the acetylation of MDH1 and that the acetylation of MDH1 is one of the cross-talk mechanisms between adipogenesis and the intracellular energy level.
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Affiliation(s)
- Eun Young Kim
- Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea
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20
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Kim WK, Choi HR, Park SG, Ko Y, Bae KH, Lee SC. Myostatin inhibits brown adipocyte differentiation via regulation of Smad3-mediated β-catenin stabilization. Int J Biochem Cell Biol 2011; 44:327-34. [PMID: 22094186 DOI: 10.1016/j.biocel.2011.11.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 11/02/2011] [Accepted: 11/02/2011] [Indexed: 12/17/2022]
Abstract
Brown adipocytes play an important role in regulating energy balance, and there is a good correlation between obesity and the amount of brown adipose tissue. Although the molecular mechanism of white adipocyte differentiation has been well characterized, brown adipogenesis has not been studied extensively. Moreover, extracellular factors that regulate brown adipogenic differentiation are not fully understood. Here, we assessed the mechanism of the regulatory action of myostatin in brown adipogenic differentiation using primary brown preadipocytes. Our results clearly showed that differentiation of brown adipocytes was significantly inhibited by myostatin treatment. In addition, myostatin-induced suppression of brown adipogenesis was observed during the early phase of differentiation. Myostatin induced the phosphorylation of Smad3, which led to increased β-catenin stabilization. These effects were blocked by treatment with a Smad3 inhibitor. Expression of brown adipocyte-related genes, such as PPAR-γ, UCP-1, PGC-1α, and PRDM16, were dramatically down-regulated by treatment with myostatin, and further down-regulated by co-treatment with a β-catenin activator. Taken together, the present study demonstrated that myostatin is a potent negative regulator of brown adipogenic differentiation by modulation of Smad3-induced β-catenin stabilization. Our findings suggest that myostatin could be used as an extracellular factor in the control of brown adipocyte differentiation.
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Affiliation(s)
- Won Kon Kim
- Medical Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea
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21
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Kim WK, Jung H, Kim EY, Kim DH, Cho YS, Park BC, Park SG, Ko Y, Bae KH, Lee SC. RPTPμ tyrosine phosphatase promotes adipogenic differentiation via modulation of p120 catenin phosphorylation. Mol Biol Cell 2011; 22:4883-91. [PMID: 21998202 PMCID: PMC3237630 DOI: 10.1091/mbc.e11-03-0175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Adipocyte differentiation can be regulated by the combined activity of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). In particular, PTPs act as key regulators in differentiation-associated signaling pathways. We recently found that receptor-type PTPμ (RPTPμ) expression is markedly increased during the adipogenic differentiation of 3T3-L1 preadipocytes and mesenchymal stem cells. Here, we investigate the functional roles of RPTPμ and the mechanism of its involvement in the regulation of signal transduction during adipogenesis of 3T3-L1 cells. Depletion of endogenous RPTPμ by RNA interference significantly inhibited adipogenic differentiation, whereas RPTPμ overexpression led to an increase in adipogenic differentiation. Ectopic expression of p120 catenin suppressed adipocyte differentiation, and the decrease in adipogenesis by p120 catenin was recovered by introducing RPTPμ. Moreover, RPTPμ induced a decrease in the cytoplasmic p120 catenin expression by reducing its tyrosine phosphorylation level, consequently leading to enhanced translocation of Glut-4 to the plasma membrane. On the basis of these results, we propose that RPTPμ acts as a positive regulator of adipogenesis by modulating the cytoplasmic p120 catenin level. Our data conclusively demonstrate that differentiation into adipocytes is controlled by RPTPμ, supporting the utility of RPTPμ and p120 catenin as novel target proteins for the treatment of obesity.
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Affiliation(s)
- Won Kon Kim
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
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22
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Kim WK, Bae KH, Choi HR, Kim DH, Choi KS, Cho YS, Kim HD, Park SG, Park BC, Ko Y, Lee SC. Leukocyte common antigen-related (LAR) tyrosine phosphatase positively regulates osteoblast differentiation by modulating extracellular signal-regulated kinase (ERK) activation. Mol Cells 2010; 30:335-40. [PMID: 20811813 DOI: 10.1007/s10059-010-0123-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 06/28/2010] [Accepted: 06/29/2010] [Indexed: 11/30/2022] Open
Abstract
Protein tyrosine phosphatases (PTPs) are pivotal regulators of key cellular functions, including cell growth, differentiation, and adhesion. Previously, we reported that leukocyte common antigen-related (LAR) tyrosine phosphatase promotes osteoblast differentiation in MC3T3-E1 preosteoblast cells. In the present study, the mechanism of the regulatory action of LAR on osteoblast differentiation was investigated. The mineralization of extracellular matrix and calcium accumulation in MC3T3-E1 cells were markedly enhanced by LAR overexpression, and these effects were further increased by treatment with a MEK inhibitor. In addition, LAR overexpression dramatically reduced extracellular signal-regulated kinase (Erk) activation during osteoblast differentiation. In contrast, a marginal effect of the inactive LAR mutant on Erk activation was detected. Expression of osteoblast-related genes such as ALP, BSP, DLX5, OCN, and RUNX2, was increased by LAR overexpression during osteoblast differentiation. On the basis of these results, we propose that LAR functions as a positive regulator of osteoblast differentiation by modulating ERK activation. Therefore, LAR phosphatase could be used as a novel regulatory target protein in many bone-associated diseases, including osteoporosis.
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Affiliation(s)
- Won Kon Kim
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806, Korea
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23
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Kim WK, Jung H, Kim DH, Kim EY, Chung JW, Cho YS, Park SG, Park BC, Ko Y, Bae KH, Lee SC. Regulation of adipogenic differentiation by LAR tyrosine phosphatase in human mesenchymal stem cells and 3T3-L1 preadipocytes. J Cell Sci 2010; 122:4160-7. [PMID: 19910497 DOI: 10.1242/jcs.053009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are multipotent adult stem cells that can differentiate into a variety of mesodermal-lineage cells. MSCs have significant potential in tissue engineering and therapeutic applications; however, the low differentiation and proliferation efficiencies of these cells in the laboratory are fundamental obstacles to their therapeutic use, mainly owing to the lack of information on the detailed signal-transduction mechanisms of differentiation into distinct lineages. With the aid of protein-tyrosine-phosphatase profiling studies, we show that the expression of leukocyte common antigen related (LAR) tyrosine phosphatase is significantly decreased during the early adipogenic stages of MSCs. Knockdown of endogenous LAR induced a dramatic increase in adipogenic differentiation, whereas its overexpression led to decreased adipogenic differentiation in both 3T3-L1 preadipocytes and MSCs. LAR reduces tyrosine phosphorylation of the insulin receptor, in turn leading to decreased phosphorylation of the adaptor protein IRS-1 and its downstream molecule Akt (also known as PKB). We propose that LAR functions as a negative regulator of adipogenesis. Furthermore, our data support the possibility that LAR controls the balance between osteoblast and adipocyte differentiation. Overall, our findings contribute to the clarification of the mechanisms underlying LAR activity in the differentiation of MSCs and suggest that LAR is a candidate target protein for the control of stem-cell differentiation.
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Affiliation(s)
- Won-Kon Kim
- Medical Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea
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24
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Jeon YJ, Kim DH, Jung H, Chung SJ, Chi SW, Cho S, Lee SC, Park BC, Park SG, Bae KH. Annexin A4 interacts with the NF-kappaB p50 subunit and modulates NF-kappaB transcriptional activity in a Ca2+-dependent manner. Cell Mol Life Sci 2010; 67:2271-81. [PMID: 20237821 PMCID: PMC11115496 DOI: 10.1007/s00018-010-0331-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 02/16/2010] [Accepted: 02/23/2010] [Indexed: 11/30/2022]
Abstract
Previously, we identified annexin A4 (ANXA4) as a candidate substrate of caspase-3. Proteomic studies were performed to identify interacting proteins with a view to determining the roles of ANXA4. ANXA4 was found to interact with the p105. Subsequent studies revealed that ANXA4 interacts with NF-kappaB through the Rel homology domain of p50. Furthermore, the interaction is markedly increased by elevated Ca(2+) levels. NF-kappaB transcriptional activity assays demonstrated that ANXA4 suppresses NF-kappaB transcriptional activity in the resting state. Following treatment with TNF-alpha or PMA, ANXA4 also suppressed NF-kappaB transcriptional activity, which was upregulated significantly early after etoposide treatment. This difference may be due to the intracellular Ca(2+) level. Additionally, ANXA4 translocates to the nucleus together with p50, and imparts greater resistance to apoptotic stimulation by etoposide. Our results collectively indicate that ANXA4 differentially modulates the NF-kappaB signaling pathway, depending on its interactions with p50 and the intracellular Ca(2+) ion level.
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Affiliation(s)
- Young-Joo Jeon
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Do-Hyung Kim
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Hyeyun Jung
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Sang J. Chung
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Seung-Wook Chi
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Sayeon Cho
- College of Pharmacy, Chung-Ang University, Seoul, 156-756 Republic of Korea
| | - Sang Chul Lee
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Byoung Chul Park
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Sung Goo Park
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
| | - Kwang-Hee Bae
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806 Republic of Korea
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