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Khan YN, Mahmud MIAM, Othman N, Radzuan HM, Basit S. Whole exome sequencing enables the correct diagnosis of Frank-Ter Haar syndrome in a Saudi family. Vavilovskii Zhurnal Genet Selektsii 2024; 28:326-331. [PMID: 38952703 PMCID: PMC11214900 DOI: 10.18699/vjgb-24-37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/05/2023] [Accepted: 11/28/2023] [Indexed: 07/03/2024] Open
Abstract
Frank-Ter Haar syndrome (FTHS) is a rare genetic hereditary autosomal recessive disorder characterized by defective malformation of cardiovascular, craniofacial, and skeletal system. Mutations in the SH3PXD2B gene are a common cause in the development of FTHS. We recruited a family with two affected individuals (3-year-old female and 2-month-old male infant) having bilateral clubfoot. Family pedigree shows an autosomal recessive mode of inheritance. DNA was extracted from the blood samples of six members of the family. Whole exome sequencing was done for the two affected individuals and the variant was validated in the whole family by using Sanger sequencing approach. Whole exome sequencing (WES) data analysis identified a rare homozygous variant (c.280C>G; p.R94G) in the SH3PXD2B gene, and Sanger sequencing showed that the same variant perfectly segregates with the phenotype in the pedigree. Moreover, the variant is predicted to be damaging and deleterious by several computation tools. Revisiting the family members for detailed clinical analysis, we diagnosed the patients as having the typical phenotype of FTHS. This study enabled us to correctly diagnose the cases of FTHS in a family initially recruited for having bilateral clubfoot by using WES. Moreover, this study identified a novel homozygous missense variant (c.280C>G; p.R94G) in (NM_001308175.2) the SH3PXD2B gene as a causative variant for autosomal recessive FTHS. This finding supports the evidence that homozygous mutations in the SH3PXD2B gene are the main cause in the development of FTHS.
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Affiliation(s)
- Y N Khan
- Department of Basic Medical Sciences, Faculty of Medicine, International Islamic University Malaysia
| | - M Imad A M Mahmud
- Department of Basic Medical Sciences, Faculty of Medicine, International Islamic University Malaysia
| | - N Othman
- Department of Basic Medical Sciences, Faculty of Medicine, International Islamic University Malaysia
| | - H M Radzuan
- Department of Basic Medical Sciences, Faculty of Medicine, International Islamic University Malaysia
| | - S Basit
- Department of Biochemistry and Molecular Medicine, College of Medicine, Taibah University Al Madinah Al Munawara, Saudi Arabia Center for Genetics and Inherited Diseases, Taibah University Al Madinah Al Munawara, Saudi Arabia
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2
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Williams JN, Irwin M, Li Y, Kambrath AV, Mattingly BT, Patel S, Kittaka M, Collins RN, Clough NA, Doud EH, Mosley AL, Bellido T, Bruzzaniti A, Plotkin LI, Trinidad JC, Thompson WR, Bonewald LF, Sankar U. Osteocyte-Derived CaMKK2 Regulates Osteoclasts and Bone Mass in a Sex-Dependent Manner through Secreted Calpastatin. Int J Mol Sci 2023; 24:4718. [PMID: 36902150 PMCID: PMC10003151 DOI: 10.3390/ijms24054718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/17/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023] Open
Abstract
Calcium/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) regulates bone remodeling through its effects on osteoblasts and osteoclasts. However, its role in osteocytes, the most abundant bone cell type and the master regulator of bone remodeling, remains unknown. Here we report that the conditional deletion of CaMKK2 from osteocytes using Dentine matrix protein 1 (Dmp1)-8kb-Cre mice led to enhanced bone mass only in female mice owing to a suppression of osteoclasts. Conditioned media isolated from female CaMKK2-deficient osteocytes inhibited osteoclast formation and function in in vitro assays, indicating a role for osteocyte-secreted factors. Proteomics analysis revealed significantly higher levels of extracellular calpastatin, a specific inhibitor of calcium-dependent cysteine proteases calpains, in female CaMKK2 null osteocyte conditioned media, compared to media from female control osteocytes. Further, exogenously added non-cell permeable recombinant calpastatin domain I elicited a marked, dose-dependent inhibition of female wild-type osteoclasts and depletion of calpastatin from female CaMKK2-deficient osteocyte conditioned media reversed the inhibition of matrix resorption by osteoclasts. Our findings reveal a novel role for extracellular calpastatin in regulating female osteoclast function and unravel a novel CaMKK2-mediated paracrine mechanism of osteoclast regulation by female osteocytes.
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Affiliation(s)
- Justin N. Williams
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Mavis Irwin
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yong Li
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Anuradha Valiya Kambrath
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Brett T. Mattingly
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Sheel Patel
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Division of Biomedical Science, Marian University College of Osteopathic Medicine, Indianapolis, IN 46022, USA
| | - Mizuho Kittaka
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN 46202, USA
| | - Rebecca N. Collins
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Nicholas A. Clough
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Emma H. Doud
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Amber L. Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Teresita Bellido
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Angela Bruzzaniti
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN 46202, USA
| | - Lilian I. Plotkin
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jonathan C. Trinidad
- Department of Chemistry, Biological Mass Spectrometry Facility, Indiana University, Bloomington, IN 47405, USA
| | - William R. Thompson
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Physical Therapy, School of Health and Human Sciences, Indianapolis, IN 46202, USA
| | - Lynda F. Bonewald
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Uma Sankar
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Belhadj S, Hermann NS, Zhu Y, Christensen G, Strasser T, Paquet-Durand F. Visualizing Cell Death in Live Retina: Using Calpain Activity Detection as a Biomarker for Retinal Degeneration. Int J Mol Sci 2022; 23:ijms23073892. [PMID: 35409251 PMCID: PMC8999672 DOI: 10.3390/ijms23073892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 01/27/2023] Open
Abstract
Calpains are a family of calcium-activated proteases involved in numerous disorders. Notably, previous studies have shown that calpain activity was substantially increased in various models for inherited retinal degeneration (RD). In the present study, we tested the capacity of the calpain-specific substrate t-BOC-Leu-Met-CMAC to detect calpain activity in living retina, in organotypic retinal explant cultures derived from wild-type mice, as well as from rd1 and RhoP23H/+ RD-mutant mice. Test conditions were refined until the calpain substrate readily detected large numbers of cells in the photoreceptor layer of RD retina but not in wild-type retina. At the same time, the calpain substrate was not obviously toxic to photoreceptor cells. Comparison of calpain activity with immunostaining for activated calpain-2 furthermore suggested that individual calpain isoforms may be active in distinct temporal stages of photoreceptor cell death. Notably, calpain-2 activity may be a relatively short-lived event, occurring only towards the end of the cell-death process. Finally, our results support the development of calpain activity detection as a novel in vivo biomarker for RD suitable for combination with non-invasive imaging techniques.
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Affiliation(s)
- Soumaya Belhadj
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (S.B.); (Y.Z.); (G.C.)
- Graduate Training Center of Neuroscience, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany;
| | - Nina Sofia Hermann
- Graduate Training Center of Neuroscience, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany;
| | - Yu Zhu
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (S.B.); (Y.Z.); (G.C.)
- Graduate Training Center of Neuroscience, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany;
| | - Gustav Christensen
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (S.B.); (Y.Z.); (G.C.)
- Graduate Training Center of Neuroscience, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany;
| | - Torsten Strasser
- Applied Vision Research Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany;
- University Eye Hospital Tübingen, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany
| | - François Paquet-Durand
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (S.B.); (Y.Z.); (G.C.)
- Correspondence:
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FAK in Cancer: From Mechanisms to Therapeutic Strategies. Int J Mol Sci 2022; 23:ijms23031726. [PMID: 35163650 PMCID: PMC8836199 DOI: 10.3390/ijms23031726] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/28/2022] [Accepted: 01/30/2022] [Indexed: 01/25/2023] Open
Abstract
Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, is overexpressed and activated in many cancer types. FAK regulates diverse cellular processes, including growth factor signaling, cell cycle progression, cell survival, cell motility, angiogenesis, and the establishment of immunosuppressive tumor microenvironments through kinase-dependent and kinase-independent scaffolding functions in the cytoplasm and nucleus. Mounting evidence has indicated that targeting FAK, either alone or in combination with other agents, may represent a promising therapeutic strategy for various cancers. In this review, we summarize the mechanisms underlying FAK-mediated signaling networks during tumor development. We also summarize the recent progress of FAK-targeted small-molecule compounds for anticancer activity from preclinical and clinical evidence.
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Augmenting MNK1/2 activation by c-FMS proteolysis promotes osteoclastogenesis and arthritic bone erosion. Bone Res 2021; 9:45. [PMID: 34671034 PMCID: PMC8528869 DOI: 10.1038/s41413-021-00162-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 04/16/2021] [Accepted: 05/25/2021] [Indexed: 01/07/2023] Open
Abstract
Osteoclasts are bone-resorbing cells that play an essential role in homeostatic bone remodeling and pathological bone erosion. Macrophage colony stimulating factor (M-CSF) is abundant in rheumatoid arthritis (RA). However, the role of M-CSF in arthritic bone erosion is not completely understood. Here, we show that M-CSF can promote osteoclastogenesis by triggering the proteolysis of c-FMS, a receptor for M-CSF, leading to the generation of FMS intracellular domain (FICD) fragments. Increased levels of FICD fragments positively regulated osteoclastogenesis but had no effect on inflammatory responses. Moreover, myeloid cell-specific FICD expression in mice resulted in significantly increased osteoclast-mediated bone resorption in an inflammatory arthritis model. The FICD formed a complex with DAP5, and the FICD/DAP5 axis promoted osteoclast differentiation by activating the MNK1/2/EIF4E pathway and enhancing NFATc1 protein expression. Moreover, targeting the MNK1/2 pathway diminished arthritic bone erosion. These results identified a novel role of c-FMS proteolysis in osteoclastogenesis and the pathogenesis of arthritic bone erosion.
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Durand B, Stoetzel C, Schaefer E, Calmels N, Scheidecker S, Kempf N, De Melo C, Guilbert AS, Timbolschi D, Donato L, Astruc D, Sauer A, Antal MC, Dollfus H, El Chehadeh S. A severe case of Frank-ter Haar syndrome and literature review: Further delineation of the phenotypical spectrum. Eur J Med Genet 2020; 63:103857. [DOI: 10.1016/j.ejmg.2020.103857] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/07/2019] [Accepted: 01/17/2020] [Indexed: 11/26/2022]
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Wang JW, Yeh CB, Chou SJ, Lu KC, Chu TH, Chen WY, Chien JL, Yen MH, Chen TH, Shyu JF. YC-1 alleviates bone loss in ovariectomized rats by inhibiting bone resorption and inducing extrinsic apoptosis in osteoclasts. J Bone Miner Metab 2018; 36:508-518. [PMID: 28983668 DOI: 10.1007/s00774-017-0866-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 08/24/2017] [Indexed: 12/27/2022]
Abstract
Osteoporosis is a major health problem in postmenopausal women and the elderly that leads to fractures associated with substantial morbidity and mortality. Current osteoporosis therapies have significant drawbacks, and the risk of fragility fractures has not yet been eliminated. There remains an unmet need for a broader range of therapeutics. Previous studies have shown that YC-1 has important regulatory functions in the cardiovascular and nervous systems. Many of the YC-1 effector molecules in platelets, smooth muscle cells and neurons, such as cGMP and μ-calpain, also have important functions in osteoclasts. In this study, we explored the effects of YC-1 on bone remodeling and determined the potential of YC-1 as a treatment for postmenopausal osteoporosis. Micro-computed tomography of lumbar vertebrae showed that YC-1 significantly improved trabecular bone microarchitecture in ovariectomized rats compared with sham-operated rats. YC-1 also significantly reversed the increases in serum bone resorption and formation in these rats, as measured by enzyme immunoassays for serum CTX-1 and P1NP, respectively. Actin ring and pit formation assays and TRAP staining analysis showed that YC-1 inhibited osteoclast activity and survival. YC-1 induced extrinsic apoptosis in osteoclasts by activating caspase-3 and caspase-8. In osteoclasts, YC-1 stimulated μ-calpain activity and inhibited Src activity. Our findings provide proof-of-concept for YC-1 as a novel antiresorptive treatment strategy for postmenopausal osteoporosis, confirming an important role of nitric oxide/cGMP/protein kinase G signaling in bone.
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Affiliation(s)
- Jin-Wen Wang
- Department of Orthopedics, Chiali Hospital, Chi Mei Medical Center, Chiali, Taiwan, ROC
| | - Chin-Bin Yeh
- Department of Psychiatry, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan, ROC
| | - Shao-Jiun Chou
- Department of General Surgery, Cardinal Tien Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan, ROC
| | - Kuo-Cheng Lu
- Department of Medicine, Cardinal Tien Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan, ROC
| | - Tzu-Hui Chu
- Department of Biology and Anatomy, National Defense Medical Center, 161 Ming Chuan E. Road Section 6, Taipei, 114, Taiwan, ROC
| | - Wei-Yu Chen
- Department of Biology and Anatomy, National Defense Medical Center, 161 Ming Chuan E. Road Section 6, Taipei, 114, Taiwan, ROC
| | - Jui-Lin Chien
- Department of Biology and Anatomy, National Defense Medical Center, 161 Ming Chuan E. Road Section 6, Taipei, 114, Taiwan, ROC
| | - Mao-Hsiung Yen
- Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Tien-Hua Chen
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming University, Taipei, Taiwan, ROC
| | - Jia-Fwu Shyu
- Department of Biology and Anatomy, National Defense Medical Center, 161 Ming Chuan E. Road Section 6, Taipei, 114, Taiwan, ROC.
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8
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Naser R, Aldehaiman A, Díaz-Galicia E, Arold ST. Endogenous Control Mechanisms of FAK and PYK2 and Their Relevance to Cancer Development. Cancers (Basel) 2018; 10:E196. [PMID: 29891810 PMCID: PMC6025627 DOI: 10.3390/cancers10060196] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 02/07/2023] Open
Abstract
Focal adhesion kinase (FAK) and its close paralogue, proline-rich tyrosine kinase 2 (PYK2), are key regulators of aggressive spreading and metastasis of cancer cells. While targeted small-molecule inhibitors of FAK and PYK2 have been found to have promising antitumor activity, their clinical long-term efficacy may be undermined by the strong capacity of cancer cells to evade anti-kinase drugs. In healthy cells, the expression and/or function of FAK and PYK2 is tightly controlled via modulation of gene expression, competing alternatively spliced forms, non-coding RNAs, and proteins that directly or indirectly affect kinase activation or protein stability. The molecular factors involved in this control are frequently deregulated in cancer cells. Here, we review the endogenous mechanisms controlling FAK and PYK2, and with particular focus on how these mechanisms could inspire or improve anticancer therapies.
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Affiliation(s)
- Rayan Naser
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
| | - Abdullah Aldehaiman
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
| | - Escarlet Díaz-Galicia
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
| | - Stefan T Arold
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
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Guan L, Lin S, Yan W, Chen L, Wang X. Effects of calcitonin on orthodontic tooth movement and associated root resorption in rats. Acta Odontol Scand 2017; 75:595-602. [PMID: 28814141 DOI: 10.1080/00016357.2017.1365375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVES Our main aim was to evaluate the effects of calcitonin (CT) on orthodontic tooth movement (OTM) and orthodontic root resorption in a rat model. MATERIAL AND METHODS Eighty male Wistar rats were randomly divided into five groups. Rats in the negative control group were not given any appliances or injections. All the remaining rats were used to establish a model of OTM. The positive control group were then injected with normal saline, while rats in the three experimental groups were injected with 0.2 IU, 1 IU or 5 IU/kg/day CT. Nickel-titanium closed-coil springs were used to deliver an initial 50 g mesial force to the left maxillary first molar for 14 days in rats in the positive control group and the experimental groups. Each group was randomly subdivided into two groups, one for analysis of tooth movement, tissue changes and tartrate-resistant acid phosphatase (TRAP)-positive cells in alveolar bone, the other to examine root resorption by scanning electron microscopy. RESULTS The OTM distance, the number of force-induced osteoclasts and root resorption areas were significantly decreased in CT-injected rats in a dose-dependent manner. CONCLUSIONS Administration of CT reduces the root resorption area and may therefore be effective as a novel adjunctive orthodontic approach to diminish undesired tooth movement via enhancing anchorage or preventing relapse after OTM.
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Affiliation(s)
- Ling Guan
- Department of Orthodontics, First Affiliated Hospital, Harbin Medical University, Harbin, P.R. China
| | - Suai Lin
- Department of Oral and Maxillofacial Surgery, Second Affiliated Hospital Harbin Medical University, Harbin, P.R. China
| | - Weijun Yan
- Department of Orthodontics, First Affiliated Hospital, Harbin Medical University, Harbin, P.R. China
| | - Lei Chen
- Department of Stomatology, The Fifth Hospital of Harbin, Harbin, P.R. China
| | - Xiaofeng Wang
- Department of Oral and Maxillofacial Surgery, Second Affiliated Hospital Harbin Medical University, Harbin, P.R. China
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St-Pierre J, Moreau F, Cornick S, Quach J, Begum S, Aracely Fernandez L, Gorman H, Chadee K. The macrophage cytoskeleton acts as a contact sensor upon interaction with Entamoeba histolytica to trigger IL-1β secretion. PLoS Pathog 2017; 13:e1006592. [PMID: 28837696 PMCID: PMC5587335 DOI: 10.1371/journal.ppat.1006592] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 09/06/2017] [Accepted: 08/18/2017] [Indexed: 01/09/2023] Open
Abstract
Entamoeba histolytica (Eh) is the causative agent of amebiasis, one of the major causes of dysentery-related morbidity worldwide. Recent studies have underlined the importance of the intercellular junction between Eh and host cells as a determinant in the pathogenesis of amebiasis. Despite the fact that direct contact and ligation between Eh surface Gal-lectin and EhCP-A5 with macrophage α5β1 integrin are absolute requirements for NLRP3 inflammasome activation and IL-1β release, many other undefined molecular events and downstream signaling occur at the interface of Eh and macrophage. In this study, we investigated the molecular events at the intercellular junction that lead to recognition of Eh through modulation of the macrophage cytoskeleton. Upon Eh contact with macrophages key cytoskeletal-associated proteins were rapidly post-translationally modified only with live Eh but not with soluble Eh proteins or fragments. Eh ligation with macrophages rapidly activated caspase-6 dependent cleavage of the cytoskeletal proteins talin, Pyk2 and paxillin and caused robust release of the pro-inflammatory cytokine, IL-1β. Macrophage cytoskeletal cleavages were dependent on Eh cysteine proteinases EhCP-A1 and EhCP-A4 but not EhCP-A5 based on pharmacological blockade of Eh enzyme inhibitors and EhCP-A5 deficient parasites. These results unravel a model where the intercellular junction between macrophages and Eh form an area of highly interacting proteins that implicate the macrophage cytoskeleton as a sensor for Eh contact that leads downstream to subsequent inflammatory immune responses. The protozoan parasite Entamoeba histolytica can establish an enteric infection in human hosts that leads to symptoms ranging from diarrhea to abscesses in the liver and the brain. Host susceptibility to amebic infection is in part determined by the quality and potency of the host immune response that occurs once the parasite overcomes the mucus bilayers and colonic epithelial barriers, and invades underlying tissues. At the cellular level, one of the key events that shape the inflammatory response occurs during direct parasite interaction with host macrophages via surface proteins. The ensuing cascades of intracellular signaling events have only partly been uncovered. Interestingly, only direct interaction between live parasites and macrophages, as opposed to soluble factors or dead parasites, is a prerequisite to the generation of a prompt raging pro-inflammatory response. We have sought to further elucidate the mechanisms by which macrophages distinguish live parasites and found that the macrophage cell skeleton undergoes rapid significant alteration upon Eh contact. Furthermore, we uncovered a previously unknown role for two Eh enzymes in triggering macrophage pro-inflammatory responses. Through this work, we gain a better understanding of the molecular interactions that occur at the macrophage-ameba interface that regulate host inflammatory responses.
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Affiliation(s)
- Joëlle St-Pierre
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - France Moreau
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Steve Cornick
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Jeanie Quach
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Sharmin Begum
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Luz Aracely Fernandez
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Hayley Gorman
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Kris Chadee
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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Chang SJ, Chen YC, Yang CH, Huang SC, Huang HK, Li CC, Harn HIC, Chiu WT. Revealing the three dimensional architecture of focal adhesion components to explain Ca 2+-mediated turnover of focal adhesions. Biochim Biophys Acta Gen Subj 2017; 1861:624-635. [PMID: 28063985 DOI: 10.1016/j.bbagen.2017.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 12/07/2016] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Focal adhesions (FAs) are large, dynamic protein complexes located close to the plasma membrane, which serve as the mechanical linkages and a biochemical signaling hub of cells. The coordinated and dynamic regulation of focal adhesion is required for cell migration. Degradation, or turnover, of FAs is a major event at the trailing edge of a migratory cell, and is mediated by Ca2+/calpain-dependent proteolysis and disassembly. Here, we investigated how Ca2+ influx induces cascades of FA turnover in living cells. METHODS Images obtained with a total internal reflection fluorescence microscope (TIRFM) showed that Ca2+ ions induce different processes in the FA molecules focal adhesion kinase (FAK), paxillin, vinculin, and talin. Three mutated calpain-resistant FA molecules, FAK-V744G, paxillin-S95G, and talin-L432G, were used to clarify the role of each FA molecule in FA turnover. RESULTS Vinculin was resistant to degradation and was not significantly affected by the presence of mutated calpain-resistant FA molecules. In contrast, talin was more sensitive to calpain-mediated turnover than the other molecules. Three-dimensional (3D) fluorescence imaging and immunoblotting demonstrated that outer FA molecules were more sensitive to calpain-mediated proteolysis than internal FA molecules. Furthermore, cell contraction is not involved in degradation of FA. CONCLUSIONS These results suggest that Ca2+-mediated degradation of FAs was mediated by both proteolysis and disassembly. The 3D architecture of FAs is related to the different dynamics of FA molecule degradation during Ca2+-mediated FA turnover. GENERAL SIGNIFICANCE This study will help us to clearly understand the underlying mechanism of focal adhesion turnover by Ca2+.
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Affiliation(s)
- Shu-Jing Chang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Ying-Chi Chen
- Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Chi-Hsun Yang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Soon-Cen Huang
- Department of Obstetrics and Gynecology, Chi Mei Medical Center, Liouying Campus, Tainan 736, Taiwan
| | - Ho-Kai Huang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Chun-Chun Li
- Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan
| | - Hans I-Chen Harn
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan
| | - Wen-Tai Chiu
- Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan; Medical Device Innovation Center, National Cheng Kung University, Tainan 701, Taiwan.
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Abstract
OBJECTIVE We investigated whether HIV-1 inhibition by SRC-family kinase inhibitors is through the non-receptor tyrosine kinase pp60 (c-SRC) and its binding partner, protein tyrosine kinase 2 beta (PTK2B). DESIGN CD4 T-lymphocytes were infected with R5 (JR-FL) or X4 (HXB2) HIV-1. We used SRC-family kinase inhibitors or targeted siRNA knockdown of c-SRC and PTK2B, then monitored effects on the early HIV-1 lifecycle. METHODS Four SRC-family kinase inhibitors or targeted siRNA knockdown were used to reduce c-SRC or PTK2B protein expression. Activated CD4 T-lymphocytes were infected with recombinant, nef-deficient, or replication-competent infectious viruses. Knockdown experiments examined early infection by monitoring: luciferase activity, expression of host surface receptors, reverse transcriptase activity, p24 levels and qPCR of reverse transcripts, integrated HIV-1, and two-long terminal repeat (2-LTR) circles. RESULTS All SRC-family kinase inhibitors inhibited R5 and X4 HIV-1 infection. Neither c-SRC nor PTK2B siRNA knockdown had an effect on cell surface receptors (CD4, CXCR4, and CCR5) nor on reverse transcriptase activity. However, using JR-FL both decreased luciferase activity while increasing late reverse transcripts (16-fold) and 2-LTR circles (eight-fold) while also decreasing viral integration (four-fold). With HXB2, c-SRC but not PTK2B siRNA knockdown produced similar results. CONCLUSIONS Our results suggest c-SRC tyrosine kinase is a major regulator of HIV-1 infection, participating in multiple stages of infection post-entry: Reduced proviral integration with increased 2-LTR circles is reminiscent of integrase inhibitors used in combination antiretroviral therapy. Decreasing c-SRC expression and/or activity provides a new target for antiviral intervention and the potential for repurposing existing FDA-approved kinase inhibitors.
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Abstract
Cell invasion of the extracellular matrix is prerequisite to cross tissue migration of tumor cells in cancer metastasis, and vascular smooth muscle cells in atherosclerosis. The tumor suppressor p53, better known for its roles in the regulation of cell cycle and apoptosis, has ignited much interest in its function as a suppressor of cell migration and invasion. How p53 and its gain-of-function mutants regulate cell invasion remains a puzzle and a challenge for future studies. In recent years, podosomes and invadopodia have also gained center stage status as veritable apparatus specialized in cell invasion. It is not clear, however, whether p53 regulates cell invasion through podosomes and invadopodia. In this review, evidence supporting a negative role of p53 in podosomes formation in vascular smooth muscle cells will be surveyed, and signaling nodes that may mediate this regulation in other cell types will be explored.
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Affiliation(s)
- Alan S Mak
- Department of Biomedical and Molecular Sciences; Queen's University; Kingston, ON Canada
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Genetic disruption of the sh3pxd2a gene reveals an essential role in mouse development and the existence of a novel isoform of tks5. PLoS One 2014; 9:e107674. [PMID: 25259869 PMCID: PMC4178035 DOI: 10.1371/journal.pone.0107674] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/12/2014] [Indexed: 01/07/2023] Open
Abstract
Tks5 is a scaffold protein and Src substrate involved in cell migration and matrix degradation through its essential role in invadosome formation and function. We have previously described that Tks5 is fundamental for zebrafish neural crest cell migration in vivo. In the present study, we sought to investigate the function of Tks5 in mammalian development by analyzing mice mutant for sh3pxd2a, the gene encoding Tks5. Homozygous disruption of the sh3pxd2a gene by gene-trapping in mouse resulted in neonatal death and the presence of a complete cleft of the secondary palate. Interestingly, embryonic fibroblasts from homozygous gene-trap sh3pxd2a mice lacked only the highest molecular weight band of the characteristic Tks5 triplet observed in protein extracts, leaving the lower molecular weight bands unaffected. This finding, together with the existence of two human Expressed Sequence Tags lacking the first 5 exons of SH3PXD2A, made us hypothesize about the presence of a second alternative transcription start site located in intron V. We performed 5′RACE on mouse fibroblasts and isolated a new transcript of the sh3pxd2a gene encoding a novel Tks5 isoform, that we named Tks5β. This novel isoform diverges from the long form of Tks5 in that it lacks the PX-domain, which confers affinity for phosphatidylinositol-3,4-bisphosphate. Instead, Tks5β has a short unique amino terminal sequence encoded by the newly discovered exon 6β; this exon includes a start codon located 29 bp from the 5'-end of exon 6. Tks5β mRNA is expressed in MEFs and all mouse adult tissues analyzed. Tks5β is a substrate for the Src tyrosine kinase and its expression is regulated through the proteasome degradation pathway. Together, these findings indicate the essentiality of the larger Tks5 isoform for correct mammalian development and the transcriptional complexity of the sh3pxd2a gene.
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15
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How to find a leucine in a haystack? Structure, ligand recognition and regulation of leucine-aspartic acid (LD) motifs. Biochem J 2014; 460:317-29. [PMID: 24870021 DOI: 10.1042/bj20140298] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
LD motifs (leucine-aspartic acid motifs) are short helical protein-protein interaction motifs that have emerged as key players in connecting cell adhesion with cell motility and survival. LD motifs are required for embryogenesis, wound healing and the evolution of multicellularity. LD motifs also play roles in disease, such as in cancer metastasis or viral infection. First described in the paxillin family of scaffolding proteins, LD motifs and similar acidic LXXLL interaction motifs have been discovered in several other proteins, whereas 16 proteins have been reported to contain LDBDs (LD motif-binding domains). Collectively, structural and functional analyses have revealed a surprising multivalency in LD motif interactions and a wide diversity in LDBD architectures. In the present review, we summarize the molecular basis for function, regulation and selectivity of LD motif interactions that has emerged from more than a decade of research. This overview highlights the intricate multi-level regulation and the inherently noisy and heterogeneous nature of signalling through short protein-protein interaction motifs.
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16
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Alam I, Koller DL, Cañete T, Blázquez G, López-Aumatell R, Martínez-Membrives E, Díaz-Morán S, Tobeña A, Fernández-Teruel A, Stridh P, Diez M, Olsson T, Johannesson M, Baud A, Econs MJ, Foroud T. High-resolution genome screen for bone mineral density in heterogeneous stock rat. J Bone Miner Res 2014; 29:1619-26. [PMID: 24643965 PMCID: PMC4074219 DOI: 10.1002/jbmr.2195] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 01/25/2014] [Accepted: 02/03/2014] [Indexed: 01/09/2023]
Abstract
We previously demonstrated that skeletal mass, structure, and biomechanical properties vary considerably in heterogeneous stock (HS) rat strains. In addition, we observed strong heritability for several of these skeletal phenotypes in the HS rat model, suggesting that it represents a unique genetic resource for dissecting the complex genetics underlying bone fragility. The purpose of this study was to identify and localize genes associated with bone mineral density in HS rats. We measured bone phenotypes from 1524 adult male and female HS rats between 17 and 20 weeks of age. Phenotypes included dual-energy X-ray absorptiometry (DXA) measurements for bone mineral content and areal bone mineral density (aBMD) for femur and lumbar spine (L3-L5), and volumetric BMD measurements by CT for the midshaft and distal femur, femur neck, and fifth lumbar vertebra (L5). A total of 70,000 polymorphic single-nucleotide polymorphisms (SNPs) distributed throughout the genome were selected from genotypes obtained from the Affymetrix rat custom SNPs array for the HS rat population. These SNPs spanned the HS rat genome with a mean linkage disequilibrium coefficient between neighboring SNPs of 0.95. Haplotypes were estimated across the entire genome for each rat using a multipoint haplotype reconstruction method, which calculates the probability of descent for each genotyped locus from each of the eight founder HS strains. The haplotypes were tested for association with each bone density phenotype via a mixed model with covariate adjustment. We identified quantitative trait loci (QTLs) for BMD phenotypes on chromosomes 2, 9, 10, and 13 meeting a conservative genomewide empiric significance threshold (false discovery rate [FDR] = 5%; p < 3 × 10(-6)). Importantly, most QTLs were localized to very small genomic regions (1-3 megabases [Mb]), allowing us to identify a narrow set of potential candidate genes including both novel genes and genes previously shown to have roles in skeletal development and homeostasis.
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Affiliation(s)
- Imranul Alam
- Medicine, Indiana University School of Medicine, IN, USA
| | - Daniel L. Koller
- Medical and Molecular Genetics, Indiana University School of Medicine, IN, USA
| | - Toni Cañete
- Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universitat Autònoma deBarcelona, 08193-Bellaterra, Barcelona, Spain
| | - Gloria Blázquez
- Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universitat Autònoma deBarcelona, 08193-Bellaterra, Barcelona, Spain
| | | | - Esther Martínez-Membrives
- Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universitat Autònoma deBarcelona, 08193-Bellaterra, Barcelona, Spain
| | - Sira Díaz-Morán
- Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universitat Autònoma deBarcelona, 08193-Bellaterra, Barcelona, Spain
| | - Adolf Tobeña
- Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universitat Autònoma deBarcelona, 08193-Bellaterra, Barcelona, Spain
| | - Alberto Fernández-Teruel
- Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universitat Autònoma deBarcelona, 08193-Bellaterra, Barcelona, Spain
| | - Pernilla Stridh
- Clinical Neuroscience, Center for Molecular Medicine, Neuroimmunolgy Unit, Karolinska Institutet, S171 76 Stockholm, Sweden
| | - Margarita Diez
- Clinical Neuroscience, Center for Molecular Medicine, Neuroimmunolgy Unit, Karolinska Institutet, S171 76 Stockholm, Sweden
| | - Tomas Olsson
- Clinical Neuroscience, Center for Molecular Medicine, Neuroimmunolgy Unit, Karolinska Institutet, S171 76 Stockholm, Sweden
| | - Martina Johannesson
- Clinical Neuroscience, Center for Molecular Medicine, Neuroimmunolgy Unit, Karolinska Institutet, S171 76 Stockholm, Sweden
| | - Amelie Baud
- Wellcome Trust Center for Human Genetics, Oxford OX3 7BN, United Kingdom
| | - Michael J. Econs
- Medicine, Indiana University School of Medicine, IN, USA
- Medical and Molecular Genetics, Indiana University School of Medicine, IN, USA
| | - Tatiana Foroud
- Medicine, Indiana University School of Medicine, IN, USA
- Medical and Molecular Genetics, Indiana University School of Medicine, IN, USA
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Steenblock C, Heckel T, Czupalla C, Espírito Santo AI, Niehage C, Sztacho M, Hoflack B. The Cdc42 guanine nucleotide exchange factor FGD6 coordinates cell polarity and endosomal membrane recycling in osteoclasts. J Biol Chem 2014; 289:18347-59. [PMID: 24821726 DOI: 10.1074/jbc.m113.504894] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The initial step of bone digestion is the adhesion of osteoclasts onto bone surfaces and the assembly of podosomal belts that segregate the bone-facing ruffled membrane from other membrane domains. During bone digestion, membrane components of the ruffled border also need to be recycled after macropinocytosis of digested bone materials. How osteoclast polarity and membrane recycling are coordinated remains unknown. Here, we show that the Cdc42-guanine nucleotide exchange factor FGD6 coordinates these events through its Src-dependent interaction with different actin-based protein networks. At the plasma membrane, FGD6 couples cell adhesion and actin dynamics by regulating podosome formation through the assembly of complexes comprising the Cdc42-interactor IQGAP1, the Rho GTPase-activating protein ARHGAP10, and the integrin interactors Talin-1/2 or Filamin A. On endosomes and transcytotic vesicles, FGD6 regulates retromer-dependent membrane recycling through its interaction with the actin nucleation-promoting factor WASH. These results provide a mechanism by which a single Cdc42-exchange factor controlling different actin-based processes coordinates cell adhesion, cell polarity, and membrane recycling during bone degradation.
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Affiliation(s)
- Charlotte Steenblock
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
| | - Tobias Heckel
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
| | - Cornelia Czupalla
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
| | - Ana Isabel Espírito Santo
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
| | - Christian Niehage
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
| | - Martin Sztacho
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
| | - Bernard Hoflack
- From the Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
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18
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Wheal BD, Beach RJ, Tanabe N, Dixon SJ, Sims SM. Subcellular elevation of cytosolic free calcium is required for osteoclast migration. J Bone Miner Res 2014; 29:725-34. [PMID: 23956003 DOI: 10.1002/jbmr.2068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 07/15/2013] [Accepted: 08/02/2013] [Indexed: 11/10/2022]
Abstract
Osteoclasts are multinucleated cells responsible for the resorption of bone and other mineralized tissues during development, physiological remodeling, and pathological bone loss. Osteoclasts have the ability to resorb substrate while concurrently migrating. However, the subcellular processes underlying migration are not well understood. It has been proposed that, in other cell types, cytosolic free Ca(2+) concentration ([Ca(2+) ]i ) regulates cell protrusion as well as retraction. Integration of these distinct events would require precise spatiotemporal patterning of subcellular Ca(2+) . The large size of osteoclasts offers a unique opportunity to monitor patterns of Ca(2+) during cell migration. We used ratiometric imaging to map [Ca(2+) ]i within rat and mouse osteoclasts. Migration was characterized by lamellipodial outgrowth at the leading edge, along with intermittent retraction of the uropod. Migrating osteoclasts displayed elevation of [Ca(2+) ]i in the uropod, that began prior to retraction. Dissipation of this [Ca(2+) ]i gradient by loading osteoclasts with the Ca(2+) chelator BAPTA abolished uropod retraction, on both glass and mineralized substrates. In contrast, elevation of [Ca(2+) ]i using ionomycin initiated prompt uropod retraction. To investigate downstream effectors, we treated cells with calpain inhibitor-1, which impaired uropod retraction. In contrast, lamellipodial outgrowth at the leading edge of osteoclasts was unaffected by any of these interventions, indicating that the signals regulating outgrowth are distinct from those triggering retraction. The large size of mature, multinucleated osteoclasts allowed us to discern a novel spatiotemporal pattern of Ca(2+) involved in cell migration. Whereas localized elevation of Ca(2+) is necessary for uropod retraction, lamellipod outgrowth is independent of Ca(2+) -a heretofore unrecognized degree of specificity underlying the regulation of osteoclast migration.
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Affiliation(s)
- Benjamin D Wheal
- Graduate Program in Neuroscience, The University of Western Ontario, London, Canada; Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
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St-Pierre J, Ostergaard HL. A role for the protein tyrosine phosphatase CD45 in macrophage adhesion through the regulation of paxillin degradation. PLoS One 2013; 8:e71531. [PMID: 23936270 PMCID: PMC3729947 DOI: 10.1371/journal.pone.0071531] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 06/28/2013] [Indexed: 11/18/2022] Open
Abstract
CD45 is a protein tyrosine phosphatase expressed on all cells of hematopoietic origin that is known to regulate Src family kinases. In macrophages, the absence of CD45 has been linked to defects in adhesion, however the molecular mechanisms involved remain poorly defined. In this study, we show that bone marrow derived macrophages from CD45-deficient mice exhibit abnormal cell morphology and defective motility. These defects are accompanied by substantially decreased levels of the cytoskeletal-associated protein paxillin, without affecting the levels of other proteins. Degradation of paxillin in CD45-deficient macrophages is calpain-mediated, as treatment with a calpain inhibitor restores paxillin levels in these cells and enhances cell spreading. Inhibition of the tyrosine kinases proline-rich tyrosine kinase (Pyk2) and focal adhesion kinase (FAK), kinases that are capable of mediating tyrosine phosphorylation of paxillin, also restored paxillin levels, indicating a role for these kinases in the CD45-dependent regulation of paxillin. These data demonstrate that CD45 functions to regulate Pyk2/FAK activity, likely through the activity of Src family kinases, which in turn regulates the levels of paxillin to modulate macrophage adhesion and migration.
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Affiliation(s)
- Joëlle St-Pierre
- Department of Medical Microbiology and Immunology, and the Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
| | - Hanne L. Ostergaard
- Department of Medical Microbiology and Immunology, and the Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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SLC4A2-mediated Cl-/HCO3- exchange activity is essential for calpain-dependent regulation of the actin cytoskeleton in osteoclasts. Proc Natl Acad Sci U S A 2013; 110:2163-8. [PMID: 23341620 DOI: 10.1073/pnas.1206392110] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bone remodeling requires osteoclasts to generate and maintain an acidified resorption compartment between the apical membrane and the bone surface to solubilize hydroxyapatite crystals within the bone matrix. This acidification process requires (i) apical proton secretion by a vacuolar H(+)-ATPase, (ii) actin cytoskeleton reorganization into a podosome belt that forms a gasket to restrict lacunar acid leakage, and (iii) basolateral chloride uptake and bicarbonate extrusion by an anion exchanger to provide Cl(-) permissive for apical acid secretion while preventing cytoplasmic alkalinization. Here we show that osteoclast-targeted deletion in mice of solute carrier family 4 anion exchanger member 2 (Slc4a2) results in osteopetrosis. We further demonstrate a previously unrecognized consequence of SLC4A2 loss of function in the osteoclast: dysregulation of calpain-dependent podosome disassembly, leading to abnormal actin belt formation, cell spreading, and migration. Rescue of SLC4A2-deficient osteoclasts with functionally defined mutants of SLC4A2 indicates regulation of actin cytoskeletal reorganization by anion-exchange activity and intracellular pH, independent of SLC4A2's long N-terminal cytoplasmic domain. These data suggest that maintenance of intracellular pH in osteoclasts through anion exchange regulates the actin superstructures required for bone resorption.
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Alarcón JA, Linde D, Barbieri G, Solano P, Caba O, Rios-Lugo MJ, Sanz M, Martin C. Calcitonin gingival crevicular fluid levels and pain discomfort during early orthodontic tooth movement in young patients. Arch Oral Biol 2012; 58:590-5. [PMID: 23107048 DOI: 10.1016/j.archoralbio.2012.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 07/05/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To investigate the previously unreported presence of calcitonin (CT) levels in gingival crevicular fluid (GCF), its variations during initial orthodontic tooth movement in both tension and compression sites, and its possible association with the experienced dental pain. DESIGN Fifteen children (mean age: 12.6 years) requiring orthodontic closure of the upper midline diastema were included. We collected GCF from the compression and tension sites of the upper right central incisor (experimental) and first bicuspid (control), before and after (1h, 24h, 7d, 15d) beginning of treatment. Calcitonin levels were determined by Western blot. Pain intensity was assessed using a visual analogue scale. RESULTS Calcitonin levels were higher in the compression site versus the control site at 7d (p=0.014). Intragroup comparisons showed an increment of CT between 1h and 7d (680.81±1672.60pg/30s, p=0.010) in the compression site. No significant changes were found in the tension and control sites. Calcitonin levels and pain intensity were negatively associated during the period from 24h to 15d (r=-0.54, p=0.05). CONCLUSIONS CT levels in the GCF significantly increased in the compression site after the short term after application of orthodontic forces. These changes were negatively associated with the perceived patient's dental pain during the period from 24h to 15d.
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Affiliation(s)
- José Antonio Alarcón
- Department of Stomatology, Section of Orthodontics, Faculty of Odontology, University of Granada, Granada, Spain.
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Focal adhesion kinases in adhesion structures and disease. JOURNAL OF SIGNAL TRANSDUCTION 2012; 2012:296450. [PMID: 22888421 PMCID: PMC3409539 DOI: 10.1155/2012/296450] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 05/25/2012] [Accepted: 05/31/2012] [Indexed: 01/07/2023]
Abstract
Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases.
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Kuo YJ, Tsuang FY, Sun JS, Lin CH, Chen CH, Li JY, Huang YC, Chen WY, Yeh CB, Shyu JF. Calcitonin inhibits SDCP-induced osteoclast apoptosis and increases its efficacy in a rat model of osteoporosis. PLoS One 2012; 7:e40272. [PMID: 22792258 PMCID: PMC3391248 DOI: 10.1371/journal.pone.0040272] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 06/04/2012] [Indexed: 12/13/2022] Open
Abstract
Introduction Treatment for osteoporosis commonly includes the use of bisphosphonates. Serious side effects of these drugs are caused by the inhibition of bone resorption as a result of osteoclast apoptosis. Treatment using calcitonin along with bisphosphonates overcomes these side-effects in some patients. Calcitonin is known to inhibit bone resorption without reducing the number of osteoclasts and is thought to prolong osteoclast survival through the inhibition of apoptosis. Further understanding of how calcitonin inhibits apoptosis could prove useful to the development of alternative treatment regimens for osteoporosis. This study aimed to analyze the mechanism by which calcitonin influences osteoclast apoptosis induced by a bisphosphate analog, sintered dicalcium pyrophosphate (SDCP), and to determine the effects of co-treatment with calcitonin and SDCP on apoptotic signaling in osteoclasts. Methods Isolated osteoclasts were treated with CT, SDCP or both for 48 h. Osteoclast apoptosis assays, pit formation assays, and tartrate-resistant acid phosphatase (TRAP) staining were performed. Using an osteoporosis rat model, ovariectomized (OVX) rats received calcitonin, SDCP, or calcitonin + SDCP. The microarchitecture of the fifth lumbar trabecular bone was investigated, and histomorphometric and biochemical analyses were performed. Results Calcitonin inhibited SDCP-induced apoptosis in primary osteoclast cultures, increased Bcl-2 and Erk activity, and decreased Mcl-1 activity. Calcitonin prevented decreased osteoclast survival but not resorption induced by SDCP. Histomorphometric analysis of the tibia revealed increased bone formation, and microcomputed tomography of the fifth lumbar vertebrate showed an additive effect of calcitonin and SDCP on bone volume. Finally, analysis of the serum bone markers CTX-I and P1NP suggests that the increased bone volume induced by co-treatment with calcitonin and SDCP may be due to decreased bone resorption and increased bone formation. Conclusions Calcitonin reduces SDCP-induced osteoclast apoptosis and increases its efficacy in an in vivo model of osteoporosis.
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Affiliation(s)
- Yi-Jie Kuo
- Department of Orthopaedic, Taipei Medical University Hospital, Taipei, Taiwan, Republic of China
- Institute of Clinical Medicine, National Yang Ming University, Taipei, Taiwan, Republic of China
| | - Fon-Yih Tsuang
- Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Republic of China
| | - Jui-Sheng Sun
- Department of Orthopaedic Surgery, National Taiwan University Hospital-Hsin Chu, Hsin-Chu, Taiwan, Republic of China
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, Republic of China
| | - Chi-Hung Lin
- Institute of Microbiology and Immunology, National Yang Ming University, Taipei, Taiwan, Republic of China
| | - Chia-Hsien Chen
- Institute of Microbiology and Immunology, National Yang Ming University, Taipei, Taiwan, Republic of China
| | - Jia-Ying Li
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Yi-Chian Huang
- Institute of Anatomy and Cell Biology National Yang Ming University, Taipei, Taiwan, Republic of China
| | - Wei-Yu Chen
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chin-Bin Yeh
- Department of Psychiatry, Tri-Service General Hospital, Taipei, Taiwan, Republic of China
| | - Jia-Fwu Shyu
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, Republic of China
- Department of Psychiatry, Tri-Service General Hospital, Taipei, Taiwan, Republic of China
- * E-mail:
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Guiet R, Vérollet C, Lamsoul I, Cougoule C, Poincloux R, Labrousse A, Calderwood DA, Glogauer M, Lutz PG, Maridonneau-Parini I. Macrophage mesenchymal migration requires podosome stabilization by filamin A. J Biol Chem 2012; 287:13051-62. [PMID: 22334688 PMCID: PMC3339984 DOI: 10.1074/jbc.m111.307124] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 02/08/2012] [Indexed: 11/06/2022] Open
Abstract
Filamin A (FLNa) is a cross-linker of actin filaments and serves as a scaffold protein mostly involved in the regulation of actin polymerization. It is distributed ubiquitously, and null mutations have strong consequences on embryonic development in humans, with organ defects which suggest deficiencies in cell migration. We have reported previously that macrophages, the archetypal migratory cells, use the protease- and podosome-dependent mesenchymal migration mode in dense three-dimensional environments, whereas they use the protease- and podosome-independent amoeboid mode in more porous matrices. Because FLNa has been shown to localize to podosomes, we hypothesized that the defects seen in patients carrying FLNa mutations could be related to the capacity of certain cell types to form podosomes. Using strategies based on FLNa knock-out, knockdown, and rescue, we show that FLNa (i) is involved in podosome stability and their organization as rosettes and three-dimensional podosomes, (ii) regulates the proteolysis of the matrix mediated by podosomes in macrophages, (iii) is required for podosome rosette formation triggered by Hck, and (iv) is necessary for mesenchymal migration but dispensable for amoeboid migration. These new functions assigned to FLNa, particularly its role in mesenchymal migration, could be directly related to the defects in cell migration described during the embryonic development in FLNa-defective patients.
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Affiliation(s)
- Romain Guiet
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - Christel Vérollet
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - Isabelle Lamsoul
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - Céline Cougoule
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - Renaud Poincloux
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - Arnaud Labrousse
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - David A. Calderwood
- the Department of Pharmacology and Cell Biology and Interdepartmental Program in Vascular Biology and Therapeutics, Yale University School of Medicine, New Haven, Connecticut 06520, and
| | - Michael Glogauer
- the CIHR Group in Matrix Dynamics, University of Toronto, Toronto, M5S 3E2 Ontario, Canada
| | - Pierre G. Lutz
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
| | - Isabelle Maridonneau-Parini
- From the CNRS, Institut de Pharmacologie et de Biologie Structurale (IPBS), Unité Mixte de Recherche 5089, 205 route de Narbonne, Toulouse, France
- Université de Toulouse, Université Paul Sabatier (UPS), IPBS, 31077 Toulouse, France
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26
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Kang H, Kwak HI, Kaunas R, Bayless KJ. Fluid shear stress and sphingosine 1-phosphate activate calpain to promote membrane type 1 matrix metalloproteinase (MT1-MMP) membrane translocation and endothelial invasion into three-dimensional collagen matrices. J Biol Chem 2011; 286:42017-42026. [PMID: 22002053 PMCID: PMC3234924 DOI: 10.1074/jbc.m111.290841] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 10/10/2011] [Indexed: 12/31/2022] Open
Abstract
The vascular endothelium continually senses and responds to biochemical and mechanical stimuli to appropriately initiate angiogenesis. We have shown previously that fluid wall shear stress (WSS) and sphingosine 1-phosphate (S1P) cooperatively initiate the invasion of human umbilical vein endothelial cells into collagen matrices (Kang, H., Bayless, K. J., and Kaunas, R. (2008) Am. J. Physiol. Heart Circ. Physiol. 295, H2087-2097). Here, we investigated the role of calpains in the regulation of endothelial cell invasion in response to WSS and S1P. Calpain inhibition significantly decreased S1P- and WSS-induced invasion. Short hairpin RNA-mediated gene silencing demonstrated that calpain 1 and 2 were required for WSS and S1P-induced invasion. Also, S1P synergized with WSS to induce invasion and to activate calpains and promote calpain membrane localization. Calpain inhibition results in a cell morphology consistent with reduced matrix proteolysis. Membrane type 1-matrix metalloproteinase (MT1-MMP) has been shown by others to regulate endothelial cell invasion, prompting us to test whether calpain acted upstream of MT1-MMP. S1P and WSS synergistically activated MT1-MMP and induced cell membrane localization of MT1-MMP in a calpain-dependent manner. Calpain activation, MT1-MMP activation and MT1-MMP membrane localization were all maximal with 5.3 dynes/cm(2) WSS and S1P treatment, which correlated with maximal invasion responses. Our data show for the first time that 5.3 dynes/cm(2) WSS in the presence of S1P combine to activate calpains, which direct MT1-MMP membrane localization to initiate endothelial sprouting into three-dimensional collagen matrices.
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Affiliation(s)
- Hojin Kang
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843
| | - Hyeong-Il Kwak
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, Texas 77843-1114
| | - Roland Kaunas
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843
| | - Kayla J Bayless
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, Texas 77843-1114.
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Mellis DJ, Itzstein C, Helfrich MH, Crockett JC. The skeleton: a multi-functional complex organ: the role of key signalling pathways in osteoclast differentiation and in bone resorption. J Endocrinol 2011; 211:131-43. [PMID: 21903860 DOI: 10.1530/joe-11-0212] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Osteoclasts are the specialised cells that resorb bone matrix and are important both for the growth and shaping of bones throughout development as well as during the process of bone remodelling that occurs throughout life to maintain a healthy skeleton. Osteoclast formation, function and survival are tightly regulated by a network of signalling pathways, many of which have been identified through the study of rare monogenic diseases, knockout mouse models and animal strains carrying naturally occurring mutations in key molecules. In this review, we describe the processes of osteoclast formation, activation and function and discuss the major transcription factors and signalling pathways (including those that control the cytoskeletal rearrangements) that are important at each stage.
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Affiliation(s)
- David J Mellis
- Musculoskeletal Research Programme, University of Aberdeen, Institute of Medical Sciences, Foresterhill, UK
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Blair HC, Robinson LJ, Huang CLH, Sun L, Friedman PA, Schlesinger PH, Zaidi M. Calcium and bone disease. Biofactors 2011; 37:159-67. [PMID: 21674636 PMCID: PMC3608212 DOI: 10.1002/biof.143] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 12/18/2010] [Indexed: 11/12/2022]
Abstract
Calcium transport and calcium signaling are of basic importance in bone cells. Bone is the major store of calcium and a key regulatory organ for calcium homeostasis. Bone, in major part, responds to calcium-dependent signals from the parathyroids and via vitamin D metabolites, although bone retains direct response to extracellular calcium if parathyroid regulation is lost. Improved understanding of calcium transporters and calcium-regulated cellular processes has resulted from analysis of genetic defects, including several defects with low or high bone mass. Osteoblasts deposit calcium by mechanisms including phosphate and calcium transport with alkalinization to absorb acid created by mineral deposition; cartilage calcium mineralization occurs by passive diffusion and phosphate production. Calcium mobilization by osteoclasts is mediated by acid secretion. Both bone forming and bone resorbing cells use calcium signals as regulators of differentiation and activity. This has been studied in more detail in osteoclasts, where both osteoclast differentiation and motility are regulated by calcium.
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Affiliation(s)
- Harry C Blair
- Department of Pathology, University of Pittsburgh, Veterans Affairs Health System, PA, USA.
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29
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Cejudo-Martin P, Courtneidge SA. Podosomal proteins as causes of human syndromes: a role in craniofacial development? Genesis 2011; 49:209-21. [PMID: 21328520 DOI: 10.1002/dvg.20732] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/21/2011] [Accepted: 02/02/2011] [Indexed: 01/12/2023]
Abstract
Podosomes and invadopodia are actin-rich protrusions of the plasma membrane important for matrix degradation and cell migration. Most of the information in this field has been obtained in cancer cells, where the presence of invadopodia has been related to increased invasiveness and metastatic potential. The importance of the related podosome structure in other pathological or physiological processes that require cell invasion is relatively unexplored. Recent evidence indicates that essential components of podosomes are responsible for several human syndromes, some of which are characterized by serious developmental defects involving the craniofacial area, skeleton and heart, and very poor prognosis. Here we will review them and discuss the possible role of podosomes as a player in correct embryo development.
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Affiliation(s)
- Pilar Cejudo-Martin
- Tumor Microenvironment Program, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA
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30
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Hong JM, Teitelbaum SL, Kim TH, Ross FP, Kim SY, Kim HJ. Calpain-6, a target molecule of glucocorticoids, regulates osteoclastic bone resorption via cytoskeletal organization and microtubule acetylation. J Bone Miner Res 2011; 26:657-65. [PMID: 20814968 PMCID: PMC3179291 DOI: 10.1002/jbmr.241] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Glucocorticoids (GCs) inhibit the resorptive capacity of the osteoclast by disrupting its cytoskeleton. We find that calpain-6 (Capn6), a unique, nonproteolytic member of its family, is suppressed 12-fold by dexamethasone (DEX) in the bone-degrading cell. While Capn6 abundance parallels commitment of naive bone marrow macrophages (BMMs) to the osteoclast phenotype, its excess or deletion does not affect the cell's differentiation. On the other hand, Capn6 localizes to the sealing zone, and its overexpression promotes osteoclast spreading and large actin ring formation, eventuating in stimulated bone degradation. Conversely, Capn6 knockdown impairs cytoskeletal organization and the cell's resorptive capacity. Capn6 complexes with tubulin, and its absence inhibits microtubule acetylation and stability in the osteoclast. Knockdown of Capn6 also reduces β(3)-integrin subunit protein, another essential regulator of osteoclast cytoskeletal function. Reflecting Capn6 as a target molecule of GCs, microtubule stability and acetylation, as well as the expression of β(3)-integrin protein, are similarly suppressed in DEX-treated osteoclasts. Moreover, overexpression of Capn6 rescues GC-mediated disruption of osteoclast cytoskeleton. Thus Capn6 promotes cytoskeletal organization and microtubule stability in osteoclasts, and its inhibition may mediate the resorption-arresting properties of GCs.
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Affiliation(s)
- Jung Min Hong
- Skeletal Diseases Genome Research Center, Kyungpook National University Hospital, Daegu, Korea
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31
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Sutherland-Smith AJ. Filamin structure, function and mechanics: are altered filamin-mediated force responses associated with human disease? Biophys Rev 2011; 3:15-23. [PMID: 28510233 DOI: 10.1007/s12551-011-0042-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 01/03/2011] [Indexed: 01/08/2023] Open
Abstract
The cytoskeleton framework is essential not only for cell structure and stability but also for dynamic processes such as cell migration, division and differentiation. The F-actin cytoskeleton is mechanically stabilised and regulated by various actin-binding proteins, one family of which are the filamins that cross-link F-actin into networks that greatly alter the elastic properties of the cytoskeleton. Filamins also interact with cell membrane-associated extracellular matrix receptors and intracellular signalling proteins providing a potential mechanism for cells to sense their external environment by linking these signalling systems. The stiffness of the external matrix to which cells are attached is an important environmental variable for cellular behaviour. In order for a cell to probe matrix stiffness, a mechanosensing mechanism functioning via alteration of protein structure and/or binding events in response to external tension is required. Current structural, mechanical, biochemical and human disease-associated evidence suggests filamins are good candidates for a role in mechanosensing.
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Affiliation(s)
- Andrew J Sutherland-Smith
- Institute of Molecular BioSciences, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand.
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32
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Functional osteoclast attachment requires inositol-1,4,5-trisphosphate receptor-associated cGMP-dependent kinase substrate. J Transl Med 2010; 90:1533-42. [PMID: 20567233 PMCID: PMC3114438 DOI: 10.1038/labinvest.2010.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Osteoclast activity is central to balanced bone turnover to maintain normal bone mass. A specialized osteoclast attachment to bone localizes acid secretion to remove bone mineral; in some cases, attachment is functionally impaired despite normal attachment proteins. The inositol-1,4,5-trisphosphate receptor-1 (IP3R1) is an intracellular calcium channel required for regulation of reversible osteoclast attachment by nitric oxide (NO), an important regulator of both normal and pathological bone degradation. In studies using human osteoclasts produced in vitro, we found that IP3R1 binds an endosomal isoform of the IP3R-associated cGMP-dependent kinase substrate (IRAG). IRAG is a substrate of cGMP-dependent kinase-1 (PKG1) and binds the PKG1 isoform PKG1β, which was the predominant form of PKG1 in human osteoclasts. Western blots of IRAG were consistent with NO-dependent serine phosphorylation of IRAG. An additional effect of PKG1β activity in osteoclasts was disassociation of IP3R1-IRAG complexes, as shown by analysis of IP3R1 complexes and by localization of the proteins within cells. IP3R1-IRAG complexes were stabilized by PKG or Src antagonists, Src activity being a requirement for IP3R1 calcium release downstream of PKG. IP3R1-mediated calcium release regulates cellular detachment in part through the calcium-dependent proteinase μ-calpain. In osteoclasts with IRAG suppressed by siRNA, activity of μ-calpain was increased relative to cells with normal IRAG, and regulation of μ-calpain by NO was lost. Furthermore, cells deficient in IRAG detached easily from substrate and had smaller attached diameters and randomly distributed podosomes, although IRAG knockdown did not affect cell viability. Our results indicate that IRAG is required for PKG1β-regulated cyclic calcium release during motility, and that disruption of the IP3R1-IRAG calcium regulation system is a novel cause of dysfunctional osteoclasts unrelated to defects in attachment proteins or acid secretion.
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33
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Iqbal Z, Cejudo-Martin P, de Brouwer A, van der Zwaag B, Ruiz-Lozano P, Scimia MC, Lindsey JD, Weinreb R, Albrecht B, Megarbane A, Alanay Y, Ben-Neriah Z, Amenduni M, Artuso R, Veltman JA, van Beusekom E, Oudakker A, Millán JL, Hennekam R, Hamel B, Courtneidge SA, van Bokhoven H. Disruption of the podosome adaptor protein TKS4 (SH3PXD2B) causes the skeletal dysplasia, eye, and cardiac abnormalities of Frank-Ter Haar Syndrome. Am J Hum Genet 2010; 86:254-61. [PMID: 20137777 DOI: 10.1016/j.ajhg.2010.01.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/17/2009] [Accepted: 01/05/2010] [Indexed: 10/25/2022] Open
Abstract
Frank-Ter Haar syndrome (FTHS), also known as Ter Haar syndrome, is an autosomal-recessive disorder characterized by skeletal, cardiovascular, and eye abnormalities, such as increased intraocular pressure, prominent eyes, and hypertelorism. We have conducted homozygosity mapping on patients representing 12 FTHS families. A locus on chromosome 5q35.1 was identified for which patients from nine families shared homozygosity. For one family, a homozygous deletion mapped exactly to the smallest region of overlapping homozygosity, which contains a single gene, SH3PXD2B. This gene encodes the TKS4 protein, a phox homology (PX) and Src homology 3 (SH3) domain-containing adaptor protein and Src substrate. This protein was recently shown to be involved in the formation of actin-rich membrane protrusions called podosomes or invadopodia, which coordinate pericellular proteolysis with cell migration. Mice lacking Tks4 also showed pronounced skeletal, eye, and cardiac abnormalities and phenocopied the majority of the defects associated with FTHS. These findings establish a role for TKS4 in FTHS and embryonic development. Mutation analysis revealed five different homozygous mutations in SH3PXD2B in seven FTHS families. No SH3PXD2B mutations were detected in six other FTHS families, demonstrating the genetic heterogeneity of this condition. Interestingly however, dermal fibroblasts from one of the individuals without an SH3PXD2B mutation nevertheless expressed lower levels of the TKS4 protein, suggesting a common mechanism underlying disease causation.
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Qin H, Cai J, Xu H, Gong Y. Inhibition of Behcet's disease by calcitonin. Med Hypotheses 2009; 73:24-6. [PMID: 19299090 DOI: 10.1016/j.mehy.2009.01.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2009] [Revised: 01/25/2009] [Accepted: 01/28/2009] [Indexed: 10/21/2022]
Abstract
Behcet's disease (BD) is a chronic, multisystem inflammatory disorder characterized by relapsing oral aphthous and genital ulcers, ocular inflammation, erythemanodosum and folliculitis-like lesions of the skin, arthritis, and central nervous system involvement. Its pathogenesis has not been fully elucidated but the etiology is accepted to be multifactorial, therefore the treatment of Behcet's disease continues to be a major therapeutic challenge. The identification of novel therapeutic agents for the treatment of these disorders is important. Calcitonin (CT), a peptide hormone secreted in response to hypercalcemia, has the dual effect of inhibiting osteoclast recruitment as well as their resorptive activity. A number of reviews have concluded that salmon calcitonin is safe and effective in the treatment of osteoporosis. Calcitonin abrogated the stimulating effect of RANKL or prednisolone; similar results were obtained with OPG. Additionally, the analgesic activity of salmon calcitonin has been shown in several controlled prospective double-blind studies to improve pain. Exogenous calcitonin is thought to cross the blood-brain barrier and to accumulate slowly in the brain, inducing analgesia once sufficient receptors are occupied. Since CT could antagonize resorptive and analgesic activity by competitively binding to CTR and has been considered as a specific antagonist, we postulate that the CT could function as a novel agent to inhibit BD. In our opinion, if the hypothesis proved to be practical, CT could be widely used in clinical settings to treat BD.
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Affiliation(s)
- Han Qin
- Department of Stomatology, The First People's Hospital Of Lianyungang City, #182 Tongguan Road, Lianyungang 222002, Jiangsu Province, China.
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35
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Abstract
We have previously shown that Wnt5A and ROR2, an orphan tyrosine kinase receptor, interact to mediate melanoma cell motility. In other cell types, this can occur through the interaction of ROR2 with the cytoskeletal protein filamin A. Here, we found that filamin A protein levels correlated with Wnt5A levels in melanoma cells. Small interfering RNA (siRNA) knockdown of WNT5A decreased filamin A expression. Knockdown of filamin A also corresponded to a decrease in melanoma cell motility. In metastatic cells, filamin A expression was predominant in the cytoplasm, which western analysis indicated was due to the cleavage of filamin A in these cells. Treatment of nonmetastatic melanoma cells with recombinant Wnt5A increased filamin A cleavage, and this could be prevented by the knockdown of ROR2 expression. Further, BAPTA-AM chelation of intracellular calcium also inhibited filamin A cleavage, leading to the hypothesis that Wnt5A/ROR2 signaling could cleave filamin A through activation of calcium-activated proteases, such as calpains. Indeed, WNT5A knockdown decreased calpain 1 expression, and by inhibiting calpain 1 either pharmacologically or using siRNA, it decreased cell motility. Our results indicate that Wnt5A activates calpain-1, leading to the cleavage of filamin A, which results in a remodeling of the cytoskeleton and an increase in melanoma cell motility.
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36
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Involvement of exon 6-mediated calpastatin intracellular movements in the modulation of calpain activation. Biochim Biophys Acta Gen Subj 2008; 1790:182-7. [PMID: 19103264 DOI: 10.1016/j.bbagen.2008.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 11/07/2008] [Accepted: 11/09/2008] [Indexed: 11/24/2022]
Abstract
BACKGROUND To establish the physiological role of calpain, it is necessary to define how the protease can escape from the effect of its natural inhibitor calpastatin, since both proteins co-localize into the cell cytosol. METHODS To answer this question, we have overexpressed four fluorescent calpastatin constructs, differing in the composition of their XL- and L-domains, and the intracellular trafficking of this protein inhibitor has been followed by single cell fluorescence imaging. RESULTS AND CONCLUSIONS By the use of these calpastatin forms differing in the type of exon-derived sequences contained in the XL- and L-domains, we have demonstrated that the sequence coded by exon 6, containing multiple phosphorylation sites, is directly involved in determining the cell localization of calpastatin. In fact, exposure to cAMP promotes the recruitment into aggregates of those calpastatin forms containing the exon 6 sequence. These protein movements are directly related to the level of cytosolic inhibitory capacity and thereby to the extent of intracellular calpain activation. GENERAL SIGNIFICANCE The recruitment of calpastatin into aggregates allows the translocation and activation of the protease to the membranes; on the contrary, the presence of large amounts of calpastatin in the cytosol prevents both processes, protecting the cell from undesired proteolysis.
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37
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Stifanese R, Averna M, De Tullio R, Salamino F, Cantoni C, Mingari MC, Prato C, Pontremoli S, Melloni E. Role of the calpain–calpastatin system in the density-dependent growth arrest. Arch Biochem Biophys 2008; 479:145-52. [DOI: 10.1016/j.abb.2008.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 09/02/2008] [Accepted: 09/02/2008] [Indexed: 01/24/2023]
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38
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Wernimont SA, Cortesio CL, Simonson WT, Huttenlocher A. Adhesions ring: a structural comparison between podosomes and the immune synapse. Eur J Cell Biol 2008; 87:507-15. [PMID: 18343530 PMCID: PMC2570187 DOI: 10.1016/j.ejcb.2008.01.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Revised: 01/16/2008] [Accepted: 01/16/2008] [Indexed: 11/30/2022] Open
Abstract
Podosomes and the immune synapse are integrin-mediated adhesive structures that share a common ring-like morphology. Both podosomes and immune synapses have a central core surrounded by a peripheral ring containing talin, vinculin and paxillin. Recent progress suggests significant parallels between the regulatory mechanisms that contribute to the formation of these adhesive structures. In this review, we compare the structures, functions and regulation of podosomes and the immune synapse.
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Affiliation(s)
- Sarah A. Wernimont
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
| | - Christa L. Cortesio
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
| | - William T.N. Simonson
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
| | - Anna Huttenlocher
- Medical Microbiology and Immunology and Pediatrics, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
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39
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Shimada M, Greer PA, McMahon AP, Bouxsein ML, Schipani E. In vivo targeted deletion of calpain small subunit, Capn4, in cells of the osteoblast lineage impairs cell proliferation, differentiation, and bone formation. J Biol Chem 2008; 283:21002-10. [PMID: 18515801 PMCID: PMC2475719 DOI: 10.1074/jbc.m710354200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 05/29/2008] [Indexed: 12/11/2022] Open
Abstract
Calpains are intracellular cysteine proteases, which include widely expressed mu- and m-calpains (1). Both mu-calpains and m-calpains are heterodimers consisting of a large catalytic subunit and a small regulatory subunit. The calpain small subunit encoded by the gene Capn4 directly binds to the intracellular C-terminal tail (C-tail) of the receptor for parathyroid hormone and parathyroid hormone-related peptide and modulates its cellular functions in osteoblasts in vitro (2). To investigate a potential role of the calpain small subunit in osteoblasts in vivo, we generated osteoblast-specific Capn4 knock-out mice using the Cre-LoxP system (3). Mutant mice had smaller bodies with shorter limbs, reduced trabecular bone with thinner cortices, and decreased osteoblast number. In vitro analysis confirmed that deletion of Capn4 in osteoblasts severely affected multiple osteoblast functions including proliferation, differentiation, and matrix mineralization. Collectively, our findings provide the first in vivo demonstration that the calpain small subunit is essential for proper osteoblast activity and bone remodeling.
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Affiliation(s)
- Masako Shimada
- Endocrine Unit, Massachusetts General Hospital and Department of Medicine, Harvard Medical School, Boston, MA 02114, USA.
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40
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Ory S, Brazier H, Pawlak G, Blangy A. Rho GTPases in osteoclasts: orchestrators of podosome arrangement. Eur J Cell Biol 2008; 87:469-77. [PMID: 18436334 DOI: 10.1016/j.ejcb.2008.03.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 01/05/2023] Open
Abstract
Cells from the myeloid lineage, namely macrophages, dendritic cells and osteoclasts, develop podosomes instead of stress fibers and focal adhesions to adhere and migrate. Podosomes share many components with focal adhesions but differ in their molecular organization, with a dense core of polymerized actin surrounded by scaffolding proteins, kinases and integrins. Podosomes are found either isolated both in macrophages and dendritic cells or arranged into superstructures in osteoclasts. When osteoclasts resorb bone, they form an F-actin rich sealing zone, which is a dense array of connected podosomes that firmly anchors osteoclasts to bone. It delineates a compartment in which protons and proteases are secreted to dissolve and degrade the mineralized matrix. Since Rho GTPases have been shown to control F-actin stress fibers and focal adhesions in mesenchymal cells, the question of whether they could also control podosome formation and arrangement in cells from the myeloid lineage, and particularly in osteoclasts, rapidly emerged. This article considers recent advances made in our understanding of podosome arrangements in osteoclasts and how Rho GTPases may control it.
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Affiliation(s)
- Stéphane Ory
- Centre de Recherche de Biochimie Macromoléculaire, UM2, CNRS, Montpellier, France.
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Cortesio CL, Chan KT, Perrin BJ, Burton NO, Zhang S, Zhang ZY, Huttenlocher A. Calpain 2 and PTP1B function in a novel pathway with Src to regulate invadopodia dynamics and breast cancer cell invasion. ACTA ACUST UNITED AC 2008; 180:957-71. [PMID: 18332219 PMCID: PMC2265405 DOI: 10.1083/jcb.200708048] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Invasive cancer cells form dynamic adhesive structures associated with matrix degradation called invadopodia. Calpain 2 is a calcium-dependent intracellular protease that regulates adhesion turnover and disassembly through the targeting of specific substrates such as talin. Here, we describe a novel function for calpain 2 in the formation of invadopodia and in the invasive abilities of breast cancer cells through the modulation of endogenous c-Src activity. Calpain-deficient breast cancer cells show impaired invadopodia formation that is rescued by expression of a truncated fragment of protein tyrosine phosphatase 1B (PTP1B) corresponding to the calpain proteolytic fragment, which indicates that calpain modulates invadopodia through PTP1B. Moreover, PTP1B activity is required for efficient invadopodia formation and breast cancer invasion, which suggests that PTP1B may modulate breast cancer progression through its effects on invadopodia. Collectively, our experiments implicate a novel signaling pathway involving calpain 2, PTP1B, and Src in the regulation of invadopodia and breast cancer invasion.
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Affiliation(s)
- Christa L Cortesio
- Department of Biomolecular Chemistry, University of Wisconsin, Madison, WI 53706, USA
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Yaroslavskiy BB, Sharrow AC, Wells A, Robinson LJ, Blair HC. Necessity of inositol (1,4,5)-trisphosphate receptor 1 and mu-calpain in NO-induced osteoclast motility. J Cell Sci 2007; 120:2884-94. [PMID: 17690304 PMCID: PMC2976040 DOI: 10.1242/jcs.004184] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In skeletal remodeling, osteoclasts degrade bone, detach and move to new locations. Mechanical stretch and estrogen regulate osteoclast motility via nitric oxide (NO). We have found previously that NO stimulates guanylyl cyclase, activating the cGMP-dependent protein kinase 1 (PKG1), reversibly terminating osteoclast matrix degradation and attachment, and initiating motility. The PKG1 substrate vasodilator-stimulated protein (VASP), a membrane-attachment-related protein found in complexes with the integrin alphavbeta3 in adherent osteoclasts, was also required for motility. Here, we studied downstream mechanisms by which the NO-dependent pathway mediates osteoclast relocation. We found that NO-stimulated motility is dependent on activation of the Ca(2+)-activated proteinase mu-calpain. RNA interference (RNAi) showed that NO-dependent activation of mu-calpain also requires PKG1 and VASP. Inhibition of Src kinases, which are involved in the regulation of adhesion complexes, also abolished NO-stimulated calpain activity. Pharmacological inhibition and RNAi showed that calpain activation in this process is mediated by the inositol (1,4,5)-trisphosphate receptor 1 [Ins(1,4,5)P(3)R1] Ca(2+) channel. We conclude that NO-induced motility in osteoclasts requires regulated Ca(2+) release, which activates mu-calpain. This occurs via the Ins(1,4,5)P(3)R1.
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Calcitonin may be a useful therapeutic agent for osteoclastogenesis syndromes involving premature eruption of the tooth. Med Hypotheses 2007; 70:1048-50. [PMID: 18023993 DOI: 10.1016/j.mehy.2007.08.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 08/06/2007] [Indexed: 11/21/2022]
Abstract
Tooth eruption is a complex and tightly regulated process that involves cells of the tooth organ and the surrounding alveolus. Recent researches have shown that tooth eruption depends on the presence of osteoclasts to create an eruption pathway through the alveolar bone. The most important physiologic role likely being at the eruptive site, in the formation of osteoclasts through signaling via the RANKL/OPG pathway. Calcitonin is an endogenous inhibitor of osteoclast development and function and thus of bone resorption. Specific calcitonin receptors are expressed on osteoclasts and their activation leads to the inhibition of osteoclast development and functions. Recent concepts about inhibiting osteoclastogenesis of calcitonin is that RANKL-induced osteoclastogenesis were blocked by the endogenous decoy receptor osteoprotegerin and were also strongly reduced by calcitonin, we hypothesize that calcitonin may has anti-eruption properties. For the clinical point of view, we can inject calcitonin in the oral mucosa of the affected tooth to inhibit bone resorption, then to facilitate root forming which may useful to premature eruption of tooth and short root anomaly disease (SRA) caused by every reasons such as hypoplasia of teeth root (HTR), Singleton-Mertern syndrome (SMS), infection and iatrogenic factors, etc.
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Shyu JF, Shih C, Tseng CY, Lin CH, Sun DT, Liu HT, Tsung HC, Chen TH, Lu RB. Calcitonin induces podosome disassembly and detachment of osteoclasts by modulating Pyk2 and Src activities. Bone 2007; 40:1329-42. [PMID: 17321230 DOI: 10.1016/j.bone.2007.01.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Revised: 01/02/2007] [Accepted: 01/19/2007] [Indexed: 01/13/2023]
Abstract
Osteoclasts (OCs) attach to the extracellular matrix via specialized attachment structures called podosomes, which form a prominent F-actin-rich ring that is thought to correspond to the sealing zone of resorbing OCs. Calcitonin (CT), a 32-amino acid polypeptide, inhibits bone resorption by decreasing motility, inducing retraction, disassembling podosome, and disrupting the actin-ring structure of OCs. However, the detailed mechanisms of how CT induces the disassembly of podosome and disruption of the adhesive structures in OCs are not well characterized. Pyk2 localizes in the sealing zone of OCs. It is activated by ligation of integrins, and then activates Src, an important signaling molecule for bone resorption. Thus, the Pyk2/Src complex in podosome could be a potential target for the CT-induced signaling. Using interference reflection, phase contrast, and confocal microscopy, CT effects on the dynamic changes of peripheral adhesive structure in living OCs were examined. CT induced dephosphorylation at Tyr(402) of Pyk2 and decreased its labeling at peripheral adhesion region, which would prevent formation of the Pyk2/Src complex in this region. CT induced increase of intracellular phosphorylation of Tyr(402) Pyk2 and increase of dephosphorylation at Tyr(527) of Src and Pyk2/Src colocalization in the central region of OCs. This evidence suggested that Src might function as an adaptor protein that competes for Pyk2 and relocates it from peripheral adhesive zone to the central region of OCs. In conclusion, CT may induce podosome reassembly and peripheral adhesive zone detachment by modulating Pyk2 and Src phosphorylation state and their intracellular distribution in OCs.
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Affiliation(s)
- Jia-Fwu Shyu
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, 161 Ming-Chuan East Rd., Sec. 6, 114 Taipei, Taiwan, ROC.
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Vermaelen M, Sirvent P, Raynaud F, Astier C, Mercier J, Lacampagne A, Cazorla O. Differential localization of autolyzed calpains 1 and 2 in slow and fast skeletal muscles in the early phase of atrophy. Am J Physiol Cell Physiol 2006; 292:C1723-31. [PMID: 17182728 DOI: 10.1152/ajpcell.00398.2006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calpains have been proposed to be involved in the cytoskeletal remodeling and wasting of skeletal muscle. However, limited data are available about the specific involvement of each calpain in the early stages of muscle atrophy. The aims of this study were to determine whether calpains 1 and 2 are autolyzed after a short period of muscle disuse, and, if so, where in the myofibers the autolyzed products are localized. In the rat soleus muscle, 5 days of immobilization increased autolyzed calpain 1 in the particulate and not the soluble fraction. Conversely, autolyzed calpain 2 was not found in the particulate fraction, whereas it was increased in the soluble fraction after immobilization. In the less atrophied plantaris muscle, no difference was noted between the control and immobilized groups whatever the fraction or calpain. Other proteolytic pathways were also investigated. The ubiquitin-proteasome pathway was activated in both skeletal muscles, and caspase 3 was activated only in the soleus muscle. Taken together, our data suggest that calpains 1 and 2 are involved in atrophy development in slow type muscle exclusively and that they have different regulation and protein targets. Moreover, the activation of proteolytic pathways appears to differ in slow and fast muscles, and the proteolytic mechanisms involved in fast-type muscle atrophy remain unclear.
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Affiliation(s)
- Marianne Vermaelen
- INSERM, ERI 25, Hôpitol Arnaud de Villneuve, 34295 Montpellier Cedex 5, France.
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Tehrani S, Faccio R, Chandrasekar I, Ross FP, Cooper JA. Cortactin has an essential and specific role in osteoclast actin assembly. Mol Biol Cell 2006; 17:2882-95. [PMID: 16611741 PMCID: PMC1483026 DOI: 10.1091/mbc.e06-03-0187] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Osteoclasts are essential for bone dynamics and calcium homeostasis. The cells form a tight seal on the bone surface, onto which they secrete acid and proteases to resorb bone. The seal is associated with a ring of actin filaments. Cortactin, a c-Src substrate known to promote Arp2/3-mediated actin assembly in vitro, is expressed in osteoclasts and localizes to the sealing ring. To address the role of cortactin and actin assembly in osteoclasts, we depleted cortactin by RNA interference. Cortactin-depleted osteoclasts displayed a complete loss of bone resorption with no formation of sealing zones. On nonosteoid surfaces, osteoclasts flatten with a dynamic, actin-rich peripheral edge that contains podosomes, filopodia, and lamellipodia. Cortactin depletion led to a specific loss of podosomes, revealing a tight spatial compartmentalization of actin assembly. Podosome formation was restored in cortactin-depleted cells by expression of wild-type cortactin or a Src homology 3 point mutant of cortactin. In contrast, expression of a cortactin mutant lacking tyrosine residues phosphorylated by Src did not restore podosome formation. Cortactin was found to be an early component of the nascent podosome belt, along with dynamin, supporting a role for cortactin in actin assembly.
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Affiliation(s)
| | | | | | - F. Patrick Ross
- Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
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