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Porrelli D, Gruppuso M, Vecchies F, Marsich E, Turco G. Alginate bone scaffolds coated with a bioactive lactose modified chitosan for human dental pulp stem cells proliferation and differentiation. Carbohydr Polym 2021; 273:118610. [PMID: 34561009 DOI: 10.1016/j.carbpol.2021.118610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 06/21/2021] [Accepted: 08/20/2021] [Indexed: 12/27/2022]
Abstract
Bioactive and biodegradable porous scaffolds can hasten the healing of bone defects; moreover, patient stem cells seeded onto scaffolds can enhance the osteoinductive and osteoconductive properties of these biomaterials. In this work, porous alginate/hydroxyapatite scaffolds were functionalized with a bioactive coating of a lactose-modified chitosan (CTL). The highly interconnected porous structure of the scaffold was homogeneously coated with CTL. The scaffolds showed remarkable stability up to 60 days of aging. Human Dental Pulp Stem Cells (hDPSCs) cultured in the presence of CTL diluted in culture medium, showed a slight and negligible increase in terms of proliferation rate; on the contrary, an effect on osteogenic differentiation of the cells was observed as a significant increase in alkaline phosphatase activity. hDPSCs showed higher cell adhesion on CTL-coated scaffolds than on uncoated ones. CTL coating did not affect cell proliferation, but stimulated cell differentiation as shown by alkaline phosphatase activity analysis.
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Affiliation(s)
- Davide Porrelli
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Piazza dell'Ospitale 1, 34125 Trieste, Italy.
| | - Martina Gruppuso
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Piazza dell'Ospitale 1, 34125 Trieste, Italy.
| | - Federica Vecchies
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, 34127 Trieste, Italy.
| | - Eleonora Marsich
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Via Licio Giorgieri 5, 34129 Trieste, Italy.
| | - Gianluca Turco
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Piazza dell'Ospitale 1, 34125 Trieste, Italy.
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2
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Chang RS, Tsai JZ, Li TY. Design and control of a ferromagnetic coded micro-carrier biochip sensor for multiplex detection of antibodies. SENSORS (BASEL, SWITZERLAND) 2011; 11:7851-7864. [PMID: 22164049 PMCID: PMC3231740 DOI: 10.3390/s110807851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 07/23/2011] [Accepted: 08/08/2011] [Indexed: 05/31/2023]
Abstract
This paper describes a method for producing a novel type of ferromagnetic coded micro-carrier. The ferromagnetic coded micro-carriers are about 200 μm in length, 200 μm in width and 50 μm in thickness, and contain eight code elements with two distinguishable codes (hollow and solid), allowing for 2(8) unique codes. The code shapes include rectangle, circle, etc. Differently shaped coded micro-carriers could carry different antigens for detection of its complementary antibody. These many shapes of coded micro-carriers would be used simultaneously allowing us to make multiple detections for different antibodies at the same time. A molding process is applied for fabrication of the ferromagnetically coded micro-carriers where Fe material (Fe powder mixed with binder) is shaped in many tiny molds to produce the coded shapes used for identification of the bio-molecules. Magnetic force is used to control the movement and location of the ferromagnetic coded micro-carriers to prevent the loss during the hybridization process. The results of image process and analysis system testing are satisfactory. The results of our micro-carrier detection system for two sets of R and B color analysis are proportional to those obtained from ELISA antibody detection.
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Affiliation(s)
- Rong-Seng Chang
- Department of Optics and Photonics, National Central University, 300 Chung-Da Rd., Chung-Li 32001, Taiwan
| | - Jang-Zern Tsai
- Department of Electrical Engineering, National Central University, 300 Chung-Da Rd., Chung-Li 32001, Taiwan; E-Mails: (J.-Z.T.); (T.-Y.L.)
| | - Tung-Yen Li
- Department of Electrical Engineering, National Central University, 300 Chung-Da Rd., Chung-Li 32001, Taiwan; E-Mails: (J.-Z.T.); (T.-Y.L.)
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3
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Differential in-gel electrophoresis (DIGE) analysis of human bone marrow osteoprogenitor cell contact guidance. Acta Biomater 2009; 5:1137-46. [PMID: 19103513 DOI: 10.1016/j.actbio.2008.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 10/30/2008] [Accepted: 11/06/2008] [Indexed: 12/29/2022]
Abstract
We have used a recent comparative proteomics technique, differential in-gel electrophoresis (DIGE), to study osteoprogenitor cell response to contact guidance in grooves. In order to increase protein output from small sample sizes, we used bioreactor culture before protein extraction and gel electrophoresis. Mass spectroscopy was used for protein identification. A number of distinct proteins were observed to exhibit significant changes in expression. These changes in protein expression suggest that the cells respond to tailored grooved topographies, with alterations in their proteome concurrent with changes in osteoprogenitor phenotype.
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Kantawong F, Burchmore R, Gadegaard N, Oreffo ROC, Dalby MJ. Proteomic analysis of human osteoprogenitor response to disordered nanotopography. J R Soc Interface 2008; 6:1075-86. [PMID: 19068473 DOI: 10.1098/rsif.2008.0447] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Previous studies have shown that microgroove-initiated contact guidance can induce bone formation in osteoprogenitor cells (OPGs) and produce changes in the cell proteome. For proteomic analysis, differential in-gel electrophoresis (DIGE) can be used as a powerful diagnostic method to provide comparable data between the proteomic profiles of cells cultured in different conditions. This study focuses on the response of OPGs to a novel nanoscale pit topography with osteoinductive properties compared with planar controls. Disordered near-square nanopits with 120 nm diameter and 100 nm depth with an average 300 nm centre-to-centre spacing (300 nm spaced pits in square pattern, but with +/-50 nm disorder) were fabricated on 1x1 cm2 polycaprolactone sheets. Human OPGs were seeded onto the test materials. DIGE analysis revealed changes in the expression of a number of distinct proteins, including upregulation of actin isoforms, beta-galectin1, vimentin and procollagen-proline, 2-oxoglutarate 4-dioxygenase and prolyl 4-hydroxylase. Downregulation of enolase, caldesmon, zyxin, GRASP55, Hsp70 (BiP/GRP78), RNH1, cathepsin D and Hsp27 was also observed. The differences in cell morphology and mineralization are also reported using histochemical techniques.
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Affiliation(s)
- Fahsai Kantawong
- Division of Infection and Immunity, Centre for Cell Engineering, Institute of Biomedical and Life Sciences, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK.
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5
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Albrethsen J, Knol JC, Jimenez CR. Unravelling the nuclear matrix proteome. J Proteomics 2008; 72:71-81. [PMID: 18957335 DOI: 10.1016/j.jprot.2008.09.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 09/29/2008] [Accepted: 09/30/2008] [Indexed: 12/28/2022]
Abstract
The nuclear matrix (NM) model posits the presence of a protein/RNA scaffold that spans the mammalian nucleus. The NM proteins are involved in basic nuclear function and are a promising source of protein biomarkers for cancer. Importantly, the NM proteome is operationally defined as the proteins from cells and tissue that are extracted following a specific biochemical protocol; in brief, the soluble proteins and lipids, cytoskeleton, and chromatin elements are removed in a sequential fashion, leaving behind the proteins that compose the NM. So far, the NM has not been sufficiently verified as a biological entity and only preliminary at the molecular level. Here, we argue for a combined effort of proteomics, immunodetection and microscopy to unravel the composition and structure of the NM.
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Affiliation(s)
- Jakob Albrethsen
- OncoProteomics Laboratory, CCA 1-60, Department Medical Oncology, VUmc-Cancer Center Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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6
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Galectin-1 in cartilage: expression, influence on chondrocyte growth and interaction with ECM components. Matrix Biol 2008; 27:513-25. [PMID: 18558481 DOI: 10.1016/j.matbio.2008.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 04/22/2008] [Accepted: 04/22/2008] [Indexed: 12/25/2022]
Abstract
Galectin-1 is a 14 kDa beta-galactoside binding protein, capable of forming lattice-like structures with glycans of cellular glycoconjugates and inducing intracellular signaling. The expression of Galectin-1 in porcine cartilage is described in this work for the first time. Immunocytochemical methods revealed distinct distribution patterns for both articular and growth plate cartilage. In articular cartilage, the highest reactivity for Galectin-1 was found in all chondrocytes at the superficial zone and in most of those at the lower layer of the middle zone. In the growth plate, marked reactivity was seen in chondrocytes at the proliferative zone and reached a maximum level for the column-forming cells at the hypertrophic zone. In addition, different Galectin-1 distribution patterns were observed at the subcellular level. With regards to the metabolic effects of Galectin-1, the results in vitro seem to indicate an inhibitory effect of Galectin-1 on articular chondrocyte anabolism (i.e. inhibition of cell proliferation and anabolic gene expression) and a stimulation of catabolic processes (i.e. induction of matrix degradation and hypertrophy marker expression). These data represent a starting point for the understanding the molecular mechanisms underlining ECM-Galectin-1 interaction and the subsequent signaling-cell transduction processes involving cartilage formation and maturation.
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Stein GS, Lian JB, van Wijnen AJ, Stein JL, Javed A, Montecino M, Choi JY, Vradii D, Zaidi SK, Pratap J, Young D. Organization of transcriptional regulatory machinery in nuclear microenvironments: implications for biological control and cancer. ADVANCES IN ENZYME REGULATION 2007; 47:242-50. [PMID: 17363043 PMCID: PMC2683591 DOI: 10.1016/j.advenzreg.2006.12.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Gary S Stein
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, 55 Lake Ave. North, Worcester, MA 01655, USA.
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Wang W, Park JW, Wang JL, Patterson RJ. Immunoprecipitation of spliceosomal RNAs by antisera to galectin-1 and galectin-3. Nucleic Acids Res 2006; 34:5166-74. [PMID: 16998182 PMCID: PMC1636441 DOI: 10.1093/nar/gkl673] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We have shown that galectin-1 and galectin-3 are functionally redundant splicing factors. Now we provide evidence that both galectins are directly associated with spliceosomes by analyzing RNAs and proteins of complexes immunoprecipitated by galectin-specific antisera. Both galectin antisera co-precipitated splicing substrate, splicing intermediates and products in active spliceosomes. Protein factors co-precipitated by the galectin antisera included the Sm core polypeptides of snRNPs, hnRNP C1/C2 and Slu7. Early spliceosomal complexes were also immunoprecipitated by these antisera. When splicing reactions were sequentially immunoprecipitated with galectin antisera, we found that galectin-1 containing spliceosomes did not contain galectin-3 and vice versa, providing an explanation for the functional redundancy of nuclear galectins in splicing. The association of galectins with spliceosomes was (i) not due to a direct interaction of galectins with the splicing substrate and (ii) easily disrupted by ionic conditions that had only a minimal effect on snRNP association. Finally, addition of excess amino terminal domain of galectin-3 inhibited incorporation of galectin-1 into splicing complexes, explaining the dominant-negative effect of the amino domain on splicing activity. We conclude that galectins are directly associated with splicing complexes throughout the splicing pathway in a mutually exclusive manner and they bind a common splicing partner through weak protein–protein interactions.
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Affiliation(s)
| | | | - John L. Wang
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast Lansing, MI 48824, USA
| | - Ronald J. Patterson
- To whom correspondence should be addressed. Tel: +1 517 355 6463/1541; Fax: +1 517 353 8957;
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9
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Spreafico A, Frediani B, Capperucci C, Chellini F, Paffetti A, D'Ambrosio C, Bernardini G, Mini R, Collodel G, Scaloni A, Marcolongo R, Santucci A. A proteomic study on human osteoblastic cells proliferation and differentiation. Proteomics 2006; 6:3520-32. [PMID: 16705754 DOI: 10.1002/pmic.200500858] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Changes in expression profiles for 17 proteins were ascertained in human mature osteoblasts compared to pre-osteoblasts (differentiation markers). A differential approach was used to highlight proteomic changes between human osteosarcoma cells and mature osteoblasts, showing a relative over-expression of 8 proteins (proliferation and tumor indicators), as well as under-expression of proteins also found down-regulated in pre-osteoblasts (specific markers of osteoblast differentiation). Our findings confirmed the differences between cell lines and primary human cell cultures and suggested caution on the use of osteosarcoma to study anti-osteoporotic drugs in humans.
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Affiliation(s)
- Adriano Spreafico
- Dipartimento di Medicina Clinica e Scienze Immunologiche, Policlinico Le Scotte, Università degli Studi di Siena, Italy
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10
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Yang JW, Kang SU, Engidawork E, Rodrigo R, Felipo V, Lubec G. Mass Spectrometrical Analysis of Galectin Proteins in Primary Rat Cerebellar Astrocytes. Neurochem Res 2006; 31:945-55. [PMID: 16804752 DOI: 10.1007/s11064-006-9100-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Accepted: 06/08/2006] [Indexed: 10/24/2022]
Abstract
Galectins are a family of animal lectins with specificity for beta-galactosides and are involved in a host of cellular activities, ranging from development to cancer. The molecules are expressed by neural and non-neural cells intracellularly as well as extracellularly. Using two-dimensional gel electrophoresis coupled to tandem mass spectrometry, the present work aimed to identify and characterize galectins in primary rat cerebellar astrocytes. The protein-chemical method identified nine spots representing two members of the galectin family, namely galectin-1 and galectin-3. These findings suggest that high abundant expression of galectin in astrocytes is limited to the two abundant galectin family members. As these family members are linked to human astrocytic tumors, their reliable detection in astrocytes by proteomic techniques would enable us to further understand their role in neural development, injury, and regeneration in general and astrocytoma in particular.
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Affiliation(s)
- J W Yang
- Department of Paediatrics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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11
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Yu X, Siegel R, Roeder RG. Interaction of the B Cell-specific Transcriptional Coactivator OCA-B and Galectin-1 and a Possible Role in Regulating BCR-mediated B Cell Proliferation. J Biol Chem 2006; 281:15505-16. [PMID: 16565088 DOI: 10.1074/jbc.m509041200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OCA-B is a B cell-specific transcriptional coactivator for OCT factors during the activation of immunoglobulin genes. In addition, OCA-B is crucial for B cell activation and germinal center formation. However, the molecular mechanisms for OCA-B function in these processes are not clear. Our previous studies documented two OCA-B isoforms and suggested a novel mechanism for the function of the myristoylated, membrane-bound form of OCA-B/p35 as a signaling molecule. Here, we report the identification of galectin-1, and related galectins, as a novel OCA-B-interacting protein. The interaction of OCA-B and galectin-1 can be detected both in vivo and in vitro. The galectin-1 binding domain in OCA-B has been localized to the N terminus of OCA-B. In B cells lacking OCA-B expression, increased galectin-1 expression, secretion, and cell surface association are observed. Consistent with these observations, and a reported inhibitory interaction of galectin-1 with CD45, the phosphatase activity of CD45 is reduced modestly, but significantly, in OCA-B-deficient B cells. Finally, galectin-1 is shown to negatively regulate B cell proliferation and tyrosine phosphorylation upon BCR stimulation. Together, these results raise the possibility that OCA-B may regulate BCR signaling through an association with galectin-1.
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Affiliation(s)
- Xin Yu
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10021, USA
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12
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Park H, Jung YK, Park OJ, Lee YJ, Choi JY, Choi Y. Interaction of Fas Ligand and Fas Expressed on Osteoclast Precursors Increases Osteoclastogenesis. THE JOURNAL OF IMMUNOLOGY 2005; 175:7193-201. [PMID: 16301623 DOI: 10.4049/jimmunol.175.11.7193] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We incidentally found that osteoclast precursors and mature osteoclasts express Fas ligand (FasL) as well as Fas, which was confirmed by flow cytometry, immunofluorescent staining, and RT-PCR. The aim of this study was to determine the role of FasL in differentiation and cell death of osteoclasts. To study the role of FasL in osteoclastogenesis, neutralizing anti-FasL mAb or rFasL was added during receptor activator of NF-kappaB ligand (RANKL)-induced osteoclastogenesis using bone marrow-derived macrophages. Neutralization of endogenous FasL by anti-FasL mAb decreased osteoclastogenesis, whereas rFasL enhanced osteoclast differentiation in a dose-dependent manner. In addition, rFasL up-regulated the secretion of osteoclastogenic cytokines, such as IL-1beta and TNF-alpha, and the activation of NF-kappaB. Functional blocking of IL-1beta and TNF-alpha using IL-1 receptor antagonist and soluble TNFR confirmed that those cytokines mediated the effect of FasL on osteoclastogenesis. The osteoclast precursors were relatively resistant to rFasL-induced apoptosis especially before RANKL treatment, resulting in minimal cell loss by rFasL treatment during osteoclastogenesis. Although rFasL increased the cell death of mature osteoclasts, growth factor withdrawal induced much more cell death. However, anti-FasL mAb did not affect the survival of mature osteoclasts, suggesting that the endogenous FasL does not have a role in the apoptosis of osteoclasts. Finally, in contrast to the effect on apoptosis, rFasL-assisted osteoclastogenesis was not mediated by caspases. In conclusion, FasL has a novel function in bone homeostasis by enhancing the differentiation of osteoclasts, which was not considered previously.
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Affiliation(s)
- Hyewon Park
- Department of Oromaxillofacial Infection & Immunity and Dental Research Institute, School of Dentistry, Seoul National University, Jongro-gu, Seoul, Republic of Korea
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Mitra P, Xie RL, Medina R, Hovhannisyan H, Zaidi SK, Wei Y, Harper JW, Stein JL, van Wijnen AJ, Stein GS. Identification of HiNF-P, a key activator of cell cycle-controlled histone H4 genes at the onset of S phase. Mol Cell Biol 2003; 23:8110-23. [PMID: 14585971 PMCID: PMC262391 DOI: 10.1128/mcb.23.22.8110-8123.2003] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
At the G(1)/S phase cell cycle transition, multiple histone genes are expressed to ensure that newly synthesized DNA is immediately packaged as chromatin. Here we have purified and functionally characterized the critical transcription factor HiNF-P, which is required for E2F-independent activation of the histone H4 multigene family. Using chromatin immunoprecipitation analysis and ligation-mediated PCR-assisted genomic sequencing, we show that HiNF-P interacts with conserved H4 cell cycle regulatory sequences in vivo. Antisense inhibition of HiNF-P reduces endogenous histone H4 gene expression. Furthermore, we find that HiNF-P utilizes NPAT/p220, a substrate of the cyclin E/cyclin-dependent kinase 2 (CDK2) kinase complex, as a key coactivator to enhance histone H4 gene transcription. The biological role of HiNF-P is reflected by impeded cell cycle progression into S phase upon antisense-mediated reduction of HiNF-P levels. Our results establish that HiNF-P is the ultimate link in a linear signaling pathway that is initiated with the growth factor-dependent induction of cyclin E/CDK2 kinase activity at the restriction point and culminates in the activation of histone H4 genes through HiNF-P at the G(1)/S phase transition.
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Affiliation(s)
- Partha Mitra
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
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14
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Luong MX, van der Meijden CM, Xing D, Hesselton R, Monuki ES, Jones SN, Lian JB, Stein JL, Stein GS, Neufeld EJ, van Wijnen AJ. Genetic ablation of the CDP/Cux protein C terminus results in hair cycle defects and reduced male fertility. Mol Cell Biol 2002; 22:1424-37. [PMID: 11839809 PMCID: PMC134686 DOI: 10.1128/mcb.22.5.1424-1437.2002] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Murine CDP/Cux, a homologue of the Drosophila Cut homeoprotein, modulates the promoter activity of cell cycle-related and cell-type-specific genes. CDP/Cux interacts with histone gene promoters as the DNA binding subunit of a large nuclear complex (HiNF-D). CDP/Cux is a ubiquitous protein containing four conserved DNA binding domains: three Cut repeats and a homeodomain. In this study, we analyzed genetically targeted mice (Cutl1(tm2Ejn), referred to as Delta C) that express a mutant CDP/Cux protein with a deletion of the C terminus, including the homeodomain. In comparison to the wild-type protein, indirect immunofluorescence showed that the mutant protein exhibited significantly reduced nuclear localization. Consistent with these data, DNA binding activity of HiNF-D was lost in nuclear extracts derived from mouse embryonic fibroblasts (MEFs) or adult tissues of homozygous mutant (Delta C(-/-)) mice, indicating the functional loss of CDP/Cux protein in the nucleus. No significant difference in growth characteristics or total histone H4 mRNA levels was observed between wild-type and Delta C(-/-) MEFs in culture. However, specific histone genes (H4.1 and H1) containing CDP/Cux binding sites have reduced expression levels in homozygous mutant MEFs. Stringent control of growth and differentiation appears to be compromised in vivo. Homozygous mutant mice have stunted growth (20 to 50% weight reduction), a high postnatal death rate of 60 to 70%, sparse abnormal coat hair, and severely reduced fertility. The deregulated hair cycle and severely diminished fertility in Cutl1(tm2Ejn/tm2Ejn) mice suggest that CDP/Cux is required for the developmental control of dermal and reproductive functions.
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Affiliation(s)
- Mai X Luong
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655-0106, USA
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15
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Javed A, Guo B, Hiebert S, Choi JY, Green J, Zhao SC, Osborne MA, Stifani S, Stein JL, Lian JB, van Wijnen AJ, Stein GS. Groucho/TLE/R-esp proteins associate with the nuclear matrix and repress RUNX (CBF(alpha)/AML/PEBP2(alpha)) dependent activation of tissue-specific gene transcription. J Cell Sci 2000; 113 ( Pt 12):2221-31. [PMID: 10825294 DOI: 10.1242/jcs.113.12.2221] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Runt related transcription factors RUNX (AML/CBF(alpha)/PEBP2(alpha)) are key regulators of hematopoiesis and osteogenesis. Using co-transfection experiments with four natural promoters, including those of the osteocalcin (OC), multi drug resistance (MDR), Rous Sarcoma Virus long terminal repeat (LTR), and bone sialoprotein (BSP) genes, we show that each of these promoters responds differently to the forced expression of RUNX proteins. However, the three RUNX subtypes (i.e. AML1, AML2, and AML3) regulate each promoter in a similar manner. Although the OC promoter is activated in a C terminus dependent manner, the MDR, LTR and BSP promoters are repressed by three distinct mechanisms, either independent of or involving the AML C terminus, or requiring only the conserved C-terminal pentapeptide VWRPY. Using yeast two hybrid assays we find that the C terminus of AML1 interacts with a Groucho/TLE/R-esp repressor protein. Co-expression assays reveal that TLE proteins repress AML dependent activation of OC gene transcription. Western and northern blot analyses suggest that TLE expression is regulated reciprocally with the levels of OC gene expression during osteoblast differentiation. Digital immunofluorescence microscopy results show that TLE1 and TLE2 are both associated with the nuclear matrix, and that a significant subset of each colocalizes with AML transcription factors. This co-localization of TLE and AML proteins is lost upon removing the C terminus of AML family members. Our findings indicate that suppression of AML-dependent gene activation by TLE proteins involves functional interactions with the C terminus of AML at the nuclear matrix in situ. Our data are consistent with the concept that the C termini of AML proteins support activation or repression of cell-type specific genes depending on the regulatory organization of the target promoter and subnuclear localization.
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Affiliation(s)
- A Javed
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA, USA
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