51
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Hu X, Ji X, Yang M, Fan S, Wang J, Lu M, Shi W, Mei L, Xu C, Fan X, Hussain M, Du J, Wu J, Wu X. Cdc42 Is Essential for Both Articular Cartilage Degeneration and Subchondral Bone Deterioration in Experimental Osteoarthritis. J Bone Miner Res 2018; 33:945-958. [PMID: 29314205 DOI: 10.1002/jbmr.3380] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/15/2017] [Accepted: 12/29/2017] [Indexed: 12/16/2022]
Abstract
Cdc42, a member of Rho family small guanosine triphosphatases (GTPases), is critical for cartilage development. We investigated the roles of Cdc42 in osteoarthritis and explored the potential mechanism underlying Cdc42-mediated articular cartilage degeneration and subchondral bone deterioration. Cdc42 is highly expressed in both articular cartilage and subchondral bone in a mouse osteoarthritis model with surgical destabilization of the medial meniscus (DMM) in the knee joints. Specifically, genetic disruption of Cdc42, knockdown of Cdc42 expression, or inhibition of Cdc42 activity robustly attenuates the DMM-induced destruction, hypertrophy, high expression of matrix metallopeptidase-13 and collagen X, and activation of Stat3 in articular cartilages. Notably, genetic disruption of Cdc42, knockdown of Cdc42 expression or inhibition of Cdc42 activity significantly restored the increased numbers of mesenchymal stem cells, osteoprogenitors, osteoblasts, osteoclasts, and neovascularized vessels, the increased bone mass, and the activated Erk1/2, Smad1/5 and Smad2 in subchondral bone of DMM-operated mice. Mechanistically, Cdc42 mediates interleukin-1β-induced interleukin-6 production and subsequent Jak/Stat3 activation to regulate chondrocytic inflammation, and also lies upstream of Erk/Smads to regulate subchondral bone remodeling during transform growth factor-β1 signaling. Cdc42 is apparently required for both articular cartilage degeneration and subchondral bone deterioration of osteoarthritis, thus, interventions targeting Cdc42 have potential in osteoarthritic therapy. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Xinhua Hu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xing Ji
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Mengting Yang
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Shihao Fan
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jirong Wang
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Meiping Lu
- Department of Rheumatology of t, he Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Shi
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Liu Mei
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Chengyun Xu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xueying Fan
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Musaddique Hussain
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jingyu Du
- Department of Orthopedics of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Junsong Wu
- Department of Orthopedics of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ximei Wu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
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52
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Kim BJ, Lee YS, Lee SY, Baek WY, Choi YJ, Moon SA, Lee SH, Kim JE, Chang EJ, Kim EY, Yoon J, Kim SW, Ryu SH, Lee SK, Lorenzo JA, Ahn SH, Kim H, Lee KU, Kim GS, Koh JM. Osteoclast-secreted SLIT3 coordinates bone resorption and formation. J Clin Invest 2018; 128:1429-1441. [PMID: 29504949 PMCID: PMC5873876 DOI: 10.1172/jci91086] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 12/28/2017] [Indexed: 01/15/2023] Open
Abstract
Coupling is the process that links bone resorption to bone formation in a temporally and spatially coordinated manner within the remodeling cycle. Several lines of evidence point to the critical roles of osteoclast-derived coupling factors in the regulation of osteoblast performance. Here, we used a fractionated secretomic approach and identified the axon-guidance molecule SLIT3 as a clastokine that stimulated osteoblast migration and proliferation by activating β-catenin. SLIT3 also inhibited bone resorption by suppressing osteoclast differentiation in an autocrine manner. Mice deficient in Slit3 or its receptor, Robo1, exhibited osteopenic phenotypes due to a decrease in bone formation and increase in bone resorption. Mice lacking Slit3 specifically in osteoclasts had low bone mass, whereas mice with either neuron-specific Slit3 deletion or osteoblast-specific Slit3 deletion had normal bone mass, thereby indicating the importance of SLIT3 as a local determinant of bone metabolism. In postmenopausal women, higher circulating SLIT3 levels were associated with increased bone mass. Notably, injection of a truncated recombinant SLIT3 markedly rescued bone loss after an ovariectomy. Thus, these results indicate that SLIT3 plays an osteoprotective role by synchronously stimulating bone formation and inhibiting bone resorption, making it a potential therapeutic target for metabolic bone diseases.
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Affiliation(s)
- Beom-Jun Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Young-Sun Lee
- Asan Institute for Life Sciences, Seoul, South Korea
| | - Sun-Young Lee
- Asan Institute for Life Sciences, Seoul, South Korea
| | | | | | - Sung Ah Moon
- Asan Institute for Life Sciences, Seoul, South Korea
| | - Seung Hun Lee
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jung-Eun Kim
- Department of Molecular Medicine, Cell and Matrix Research Institute, Kyungpook National University School of Medicine, Daegu, South Korea
| | | | | | - Jin Yoon
- Department of Pharmacology, University of Ulsan College of Medicine, Seoul, South Korea
| | - Seung-Whan Kim
- Department of Pharmacology, University of Ulsan College of Medicine, Seoul, South Korea
| | - Sung Ho Ryu
- Department of Life Science, Pohang University of Science and Technology, Pohang, Kyungbook, South Korea
| | | | - Joseph A. Lorenzo
- Departments of Medicine and Orthopaedics, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Seong Hee Ahn
- Department of Internal Medicine, Inha University School of Medicine, Incheon, South Korea
| | - Hyeonmok Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Ki-Up Lee
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Ghi Su Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jung-Min Koh
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
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53
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Xu S, Zhang Y, Wang J, Li K, Tan K, Liang K, Shen J, Cai D, Jin D, Li M, Xiao G, Xu J, Jiang Y, Bai X. TSC1 regulates osteoclast podosome organization and bone resorption through mTORC1 and Rac1/Cdc42. Cell Death Differ 2018; 25:1549-1566. [PMID: 29358671 DOI: 10.1038/s41418-017-0049-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 11/13/2017] [Accepted: 11/27/2017] [Indexed: 01/08/2023] Open
Abstract
Reorganization of the podosome into the sealing zone is crucial for osteoclasts (OCLs) to resorb bone, but the underlying mechanisms are unclear. Here, we show that tuberous sclerosis complex 1 (TSC1) functions centrally in OCLs to promote podosome organization and bone resorption through mechanistic target of rapamycin complex 1 (mTORC1) and the small GTPases Rac1/Cdc42. During osteoclastogenesis, enhanced expression of TSC1 downregulates mTORC1 activity. TSC1 deletion in OCLs reduced podosome belt formation in vitro and sealing zone formation in vivo, leading to bone resorption deficiency and osteopetrosis. Mechanistically, TSC1 promoted podosome superstructure assembly by releasing mTORC1-dependent negative feedback inhibition of Rac1/Cdc42. Rapamycin and active Rac1/Cdc42 restore podosome organization and bone resorption and alleviate osteopetrotic phenotypes in mutant mice. Our findings reveal an essential role of TSC1 signaling in the regulation of bone resorption. Targeting TSC1 represents a novel strategy to inhibit bone resorption and prevent bone loss-related diseases.
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Affiliation(s)
- Song Xu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.,Department of Arthroplasty, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Yue Zhang
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.,Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital of Southern Medical University, Guangzhou, 510630, China
| | - Jian Wang
- Department of Arthroplasty, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Kai Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.,Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital of Southern Medical University, Guangzhou, 510630, China
| | - Kang Tan
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Kangyan Liang
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Junhui Shen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Daozhang Cai
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital of Southern Medical University, Guangzhou, 510630, China
| | - Dadi Jin
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital of Southern Medical University, Guangzhou, 510630, China
| | - Mangmang Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Guozhi Xiao
- Department of Biochemistry and Department of Biology and Shenzhen Key Laboratory of Cell Microenvironment, South University of Science and Technology of China, Shenzhen, 518055, China
| | - Jiake Xu
- Molecular Laboratory, School of Pathology and Laboratory Medicine, The University of Western Australia, M504, Perth, 6009, Australia
| | - Yu Jiang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, 15260, USA
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China. .,Department of Arthroplasty, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
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Abstract
The actin cytoskeleton is essential for the biology of osteoclasts, in particular during bone resorption. As key regulators of actin dynamics, the small GTPases of the Rho family are very important in the control of osteoclast activity. The study of Rho GTPase signaling pathways is essential to uncover the mechanisms of bone resorption and can have interesting applications for the treatment of osteolytic diseases. In this chapter, we describe various techniques to obtain primary osteoclasts from murine bone marrow cells, to measure Rho GTPase activation levels, to monitor bone resorption activity of osteoclasts and to introduce the expression of proteins of interest using a retroviral approach. We illustrate the different methods with experimental examples of the effect of Rac1 activation by the exchange factor Dock5 on bone resorption by osteoclasts.
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Affiliation(s)
- Anne Morel
- CRBM CNRS UMR 5237, Montpellier, France
- Montpellier University, Montpellier, France
| | - Anne Blangy
- CRBM CNRS UMR 5237, Montpellier, France.
- Montpellier University, Montpellier, France.
| | - Virginie Vives
- CRBM CNRS UMR 5237, Montpellier, France
- Montpellier University, Montpellier, France
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55
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Iwatake M, Nishishita K, Okamoto K, Tsukuba T. The Rho-specific guanine nucleotide exchange factor Plekhg5 modulates cell polarity, adhesion, migration, and podosome organization in macrophages and osteoclasts. Exp Cell Res 2017; 359:415-430. [PMID: 28847484 DOI: 10.1016/j.yexcr.2017.08.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/06/2017] [Accepted: 08/17/2017] [Indexed: 12/28/2022]
Abstract
Osteoclasts are multinucleated bone-resorbing cells that are formed by fusion of monocyte/macrophage lineage. Osteoclasts and macrophages generate podosomes that are actin-based dynamic organelles implicated in cell adhesion, spreading, migration, and degradation. However, the detailed mechanisms of podosome organization remain unknown. Here, we identified the Rho-specific guanine-nucleotide exchange factor (Rho-GEF) Plekhg5 as an up-regulated gene during differentiation of osteoclasts from macrophages. Knockdown of Plekhg5 with small interfering RNA in both macrophages and osteoclasts induced larger cell formation with impaired cell polarity and resulted in an elongated and flattened shape. In macrophages, Plekhg5 depletion enhanced random migration, but impaired directional migration, adhesion, and matrix degradation. Plekhg5 in osteoclasts affected random migration, podosome organization, and bone resorption. Plekhg5 depletion affected signaling and localization of several Rho downstream effectors. In fact, end-binding protein 1 (EB1), cofilin and vinculin were abnormally localized in Plekhg5-depleted cells, and mDia1 and LIM kinase (LIMK)1 were upregulated in Plekhg5-depleted cells compared with control cells. However, overexpression of Plekhg5 in macrophages induced an increase in its mRNA level, but failed to increase the protein level, indicating that overexpressed Plekhg5 was degraded in macrophages but not HEK293T cells. Thus, Plekhg5 affects cell polarity, migration, adhesion, degradation, and podosome organization in macrophages and osteoclasts.
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Affiliation(s)
- Mayumi Iwatake
- Department of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| | - Kazuhisa Nishishita
- Department of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| | - Kuniaki Okamoto
- Department of Dental Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Takayuki Tsukuba
- Department of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan.
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56
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Stimulation of osteoclast migration and bone resorption by C-C chemokine ligands 19 and 21. Exp Mol Med 2017; 49:e358. [PMID: 28729639 PMCID: PMC5565950 DOI: 10.1038/emm.2017.100] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 01/22/2017] [Accepted: 01/31/2017] [Indexed: 01/26/2023] Open
Abstract
Osteoclasts are responsible for the bone erosion associated with rheumatoid arthritis (RA). The upregulation of the chemokines CCL19 and CCL21 and their receptor CCR7 has been linked to RA pathogenesis. The purpose of this study was to evaluate the effects of CCL19 and CCL21 on osteoclasts and to reveal their underlying mechanisms. The expression of CCL19, CCL21 and CCR7 was higher in RA patients than in osteoarthritis patients. In differentiating osteoclasts, tumor necrosis factor-α, interleukin-1β and lipopolysaccharide stimulated CCR7 expression. CCL19 and CCL21 promoted osteoclast migration and resorption activity. These effects were dependent on the presence of CCR7 and abolished by the inhibition of the Rho signaling pathway. CCL19 and CCL21 promoted bone resorption by osteoclasts in an in vivo mice calvarial model. These findings demonstrate for the first time that CCL19, CCL21 and CCR7 play important roles in bone destruction by increasing osteoclast migration and resorption activity. This study also suggests that the interaction of CCL19 and CCL21 with CCR7 is an effective strategic focus in developing therapeutics for alleviating inflammatory bone destruction.
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57
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Xing WR, Goodluck H, Zeng C, Mohan S. Role and mechanism of action of leucine-rich repeat kinase 1 in bone. Bone Res 2017; 5:17003. [PMID: 28326224 PMCID: PMC5348726 DOI: 10.1038/boneres.2017.3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/06/2016] [Accepted: 12/13/2016] [Indexed: 12/13/2022] Open
Abstract
Leucine-rich repeat kinase 1 (LRRK1) plays a critical role in regulating cytoskeletal organization, osteoclast activity, and bone resorption with little effect on bone formation parameters. Deficiency of Lrrk1 in mice causes a severe osteopetrosis in the metaphysis of the long bones and vertebrae bones, which makes LRRK1 an attractive alternative drug target for the treatment of osteoporosis and other high-turnover bone diseases. This review summarizes recent advances on the functions of the Lrrk1-related family members, Lrrk1 deficiency-induced skeletal phenotypes, LRRK1 structure–function, potential biological substrates and interacting proteins, and the mechanisms of LRRK1 action in osteoclasts.
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Affiliation(s)
- Weirong R Xing
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA, USA; Department of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Helen Goodluck
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center , Loma Linda, CA, USA
| | - Canjun Zeng
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA, USA; Department of Orthopedics, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Subburaman Mohan
- Musculoskeletal Disease Center, Jerry L. Pettis Memorial VA Medical Center, Loma Linda, CA, USA; Department of Medicine, Loma Linda University, Loma Linda, CA, USA
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58
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Abstract
Macrophages are found in all tissues and regulate tissue morphogenesis during development through trophic and scavenger functions. The colony stimulating factor-1 (CSF-1) receptor (CSF-1R) is the major regulator of tissue macrophage development and maintenance. In combination with receptor activator of nuclear factor κB (RANK), the CSF-1R also regulates the differentiation of the bone-resorbing osteoclast and controls bone remodeling during embryonic and early postnatal development. CSF-1R-regulated macrophages play trophic and remodeling roles in development. Outside the mononuclear phagocytic system, the CSF-1R directly regulates neuronal survival and differentiation, the development of intestinal Paneth cells and of preimplantation embryos, as well as trophoblast innate immune function. Consistent with the pleiotropic roles of the receptor during development, CSF-1R deficiency in most mouse strains causes embryonic or perinatal death and the surviving mice exhibit multiple developmental and functional deficits. The CSF-1R is activated by two dimeric glycoprotein ligands, CSF-1, and interleukin-34 (IL-34). Homozygous Csf1-null mutations phenocopy most of the deficits of Csf1r-null mice. In contrast, Il34-null mice have no gross phenotype, except for decreased numbers of Langerhans cells and microglia, indicating that CSF-1 plays the major developmental role. Homozygous inactivating mutations of the Csf1r or its ligands have not been reported in man. However, heterozygous inactivating mutations in the Csf1r lead to a dominantly inherited adult-onset progressive dementia, highlighting the importance of CSF-1R signaling in the brain.
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Affiliation(s)
- Violeta Chitu
- Albert Einstein College of Medicine, Bronx, NY, United States
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59
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Ye S, Fujiwara T, Zhou J, Varughese KI, Zhao H. LIS1 Regulates Osteoclastogenesis through Modulation of M-SCF and RANKL Signaling Pathways and CDC42. Int J Biol Sci 2016; 12:1488-1499. [PMID: 27994513 PMCID: PMC5166490 DOI: 10.7150/ijbs.15583] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 09/11/2016] [Indexed: 01/28/2023] Open
Abstract
We have previously reported that depletion of LIS1, a key regulator of microtubules and cytoplasmic dynein motor complex, in osteoclast precursor cells by shRNAs attenuates osteoclastogenesis in vitro. However, the underlying mechanisms remain unclear. In this study, we show that conditional deletion of LIS1 in osteoclast progenitors in mice led to increased bone mass and decreased osteoclast number on trabecular bone. In vitro mechanistic studies revealed that loss of LIS1 had little effects on cell cycle progression but accelerated apoptosis of osteoclast precursor cells. Furthermore, deletion of LIS1 prevented prolonged activation of ERK by M-CSF and aberrantly enhanced prolonged JNK activation stimulated by RANKL. Finally, lack of LIS1 abrogated M-CSF and RANKL induced CDC42 activation and retroviral transduction of a constitutively active form of CDC42 partially rescued osteoclastogenesis in LIS1-deficient macrophages. Therefore, these data identify a key role of LIS1 in regulation of cell survival of osteoclast progenitors by modulating M-CSF and RANKL induced signaling pathways and CDC42 activation.
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Affiliation(s)
- Shiqiao Ye
- Center for Osteoporosis and Metabolic Bone Diseases, Division of Endocrinology and Metabolism, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Toshifumi Fujiwara
- Center for Osteoporosis and Metabolic Bone Diseases, Division of Endocrinology and Metabolism, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jian Zhou
- Center for Osteoporosis and Metabolic Bone Diseases, Division of Endocrinology and Metabolism, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA;; Department of Orthopedics, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, P. R. China
| | - Kottayil I Varughese
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Haibo Zhao
- Center for Osteoporosis and Metabolic Bone Diseases, Division of Endocrinology and Metabolism, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA;; Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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60
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Wang JR, Wang CJ, Xu CY, Wu XK, Hong D, Shi W, Gong Y, Chen HX, Long F, Wu XM. Signaling Cascades Governing Cdc42-Mediated Chondrogenic Differentiation and Mensenchymal Condensation. Genetics 2016; 202:1055-69. [PMID: 26739452 PMCID: PMC4787953 DOI: 10.1534/genetics.115.180109] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 12/30/2015] [Indexed: 12/30/2022] Open
Abstract
Endochondral ossification consists of successive steps of chondrocyte differentiation, including mesenchymal condensation, differentiation of chondrocytes, and hypertrophy followed by mineralization and ossification. Loss-of-function studies have revealed that abnormal growth plate cartilage of the Cdc42 mutant contributes to the defects in endochondral bone formation. Here, we have investigated the roles of Cdc42 in osteogenesis and signaling cascades governing Cdc42-mediated chondrogenic differentiation. Though deletion of Cdc42 in limb mesenchymal progenitors led to severe defects in endochondral ossification, either ablation of Cdc42 in limb preosteoblasts or knockdown of Cdc42 in vitro had no obvious effects on bone formation and osteoblast differentiation. However, in Cdc42 mutant limb buds, loss of Cdc42 in mesenchymal progenitors led to marked inactivation of p38 and Smad1/5, and in micromass cultures, Cdc42 lay on the upstream of p38 to activate Smad1/5 in bone morphogenetic protein-2-induced mesenchymal condensation. Finally, Cdc42 also lay on the upstream of protein kinase B to transactivate Sox9 and subsequently induced the expression of chondrocyte differential marker in transforming growth factor-β1-induced chondrogenesis. Taken together, by using biochemical and genetic approaches, we have demonstrated that Cdc42 is involved not in osteogenesis but in chondrogenesis in which the BMP2/Cdc42/Pak/p38/Smad signaling module promotes mesenchymal condensation and the TGF-β/Cdc42/Pak/Akt/Sox9 signaling module facilitates chondrogenic differentiation.
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Affiliation(s)
- Jirong R Wang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Chaojun J Wang
- Department of Urology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Chengyun Y Xu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Xiaokai K Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Dun Hong
- Department of Urology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Wei Shi
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Ying Gong
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Haixiao X Chen
- Department of Orthopedics, Taizhou Hospital, Linhai 317000, China
| | - Fanxin Long
- Departments of Orthopaedic Surgery, Medicine and Developmental Biology, Washington University, St. Louis, Missouri 63110
| | - Ximei M Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058, China Departments of Orthopaedic Surgery, Medicine and Developmental Biology, Washington University, St. Louis, Missouri 63110
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61
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Kim JH, Kim K, Kim I, Seong S, Nam KI, Lee SH, Kim KK, Kim N. Role of CrkII Signaling in RANKL-Induced Osteoclast Differentiation and Function. THE JOURNAL OF IMMUNOLOGY 2015; 196:1123-31. [PMID: 26695370 DOI: 10.4049/jimmunol.1501998] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/22/2015] [Indexed: 11/19/2022]
Abstract
Rac1, a member of small GTPases, is a key regulator of osteoclast differentiation and function. The Crk family adaptor proteins, consisting of Src homology (SH) 2 and SH3 protein-binding domains, regulate cell proliferation, migration, and invasion through Rac1 activation. In this study, we examined the role of CrkII in osteoclast differentiation and function. Retroviral overexpression of CrkII in osteoclast precursors enhanced osteoclast differentiation and resorptive function through Rac1 activation. The knockdown of CrkII in osteoclast precursors using small interfering RNA inhibited osteoclast differentiation and its resorption activity. Unlike wild-type CrkII, overexpression of the three SH domains in mutant forms of CrkII did not enhance either osteoclast differentiation or function. Phosphorylation of p130 Crk-associated substrate (p130Cas) by osteoclastogenic cytokines in preosteoclasts increased the interaction between p130Cas and CrkII, which is known to be involved in Rac1 activation. Furthermore, transgenic mice overexpressing CrkII under control of a tartrate-resistant acid phosphatase promoter exhibited a low bone mass phenotype, associated with increased resorptive function of osteoclasts in vivo. Taken together, our data suggest that the p130Cas/CrkII/Rac1 signaling pathway plays an important role in osteoclast differentiation and function, both in vitro and in vivo.
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Affiliation(s)
- Jung Ha Kim
- Department of Pharmacology, Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea
| | - Kabsun Kim
- Department of Pharmacology, Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea
| | - Inyoung Kim
- Department of Pharmacology, Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea
| | - Semun Seong
- Department of Pharmacology, Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea
| | - Kwang-Il Nam
- Department of Anatomy, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea; and
| | - Seoung Hoon Lee
- Department of Oral Microbiology and Immunology, Wonkwang University School of Dentistry, Iksan 570-749, Republic of Korea
| | - Kyung Keun Kim
- Department of Pharmacology, Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea
| | - Nacksung Kim
- Department of Pharmacology, Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea;
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62
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Zhang H, Fu Y, Shi Z, Su Y, Zhang J. miR-17 is involved in Japanese Flounder (Paralichthys olivaceus) development by targeting the Cdc42 mRNA. Comp Biochem Physiol B Biochem Mol Biol 2015; 191:163-70. [PMID: 26546744 DOI: 10.1016/j.cbpb.2015.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 10/14/2015] [Accepted: 10/14/2015] [Indexed: 01/27/2023]
Abstract
The expression patterns of 197 miRNAs during Japanese flounder metamorphic development were recently analyzed. miR-17 was differentially expressed during the metamorphic period of the Japanese flounder; however, the role of miR-17 in Japanese flounder development has remained elusive to date. Bioinformatics analysis showed that Cdc42 was a putative target of miR-17. Cdc42 is a gene related to cell adhesion, migration, polarity, cytokinesis, growth, actin cytoskeleton, microtubule dynamics and transcription factor activity; thus, Cdc42 may contribute to metamorphic development. In our study, overexpression of miR-17 in FEC cells suppressed Cdc42 expression. The luciferase reporter assay confirmed that Cdc42 was the target of miR-17. The Cdc42 cDNA from the Japanese flounder was cloned and characterized for the first time. The expression of miR-17 was found to be negatively correlated with Cdc42 mRNA expression during temporal development and in the tissues of adult Japanese flounders. These results indicated that the decrease in miR-17 contributed to the up-regulation of Cdc42 during Japanese flounder metamorphosis. Cdc42 gene expression was down-regulated by thyroid hormone during Japanese flounder metamorphosis, whereas miR-17 was significantly up-regulated by thyroid hormone during these stages. These results indicated that miR-17 was a negative regulator of Cdc42.
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Affiliation(s)
- Hongmei Zhang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Yuanshuai Fu
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Zhiyi Shi
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China.
| | - Yanfang Su
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Junling Zhang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
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Choi SW, Yeon JT, Ryu BJ, Kim KJ, Moon SH, Lee H, Lee MS, Lee SY, Heo JC, Park SJ, Kim SH. Repositioning Potential of PAK4 to Osteoclastic Bone Resorption. J Bone Miner Res 2015; 30:1494-507. [PMID: 25640698 DOI: 10.1002/jbmr.2468] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 11/10/2022]
Abstract
Drug repositioning is a rational approach for expanding the use of existing drugs or candidate drugs to treat additional disorders. Here we investigated the possibility of using the anticancer p21-activated kinase 4 (PAK4)-targeted inhibitor PF-3758309 to treat osteoclast-mediated disorders. PAK4 was highly expressed in bone marrow cells and was phosphorylated during their differentiation into osteoclasts, and osteoclast differentiation was significantly inhibited by the dominant negative form of PAK4 and by PF-3758309. Specifically, PF-3758309 significantly inhibited the fusion of preosteoclasts, the podosome formation, and the migration of preosteoclasts. PF-3758309 also had in vivo antiresorptive activity in a lipopolysaccharide-induced bone erosion model and in vitro antiosteoclastogenic activity in the differentiation of human bone marrow-derived cells and peripheral blood mononuclear cells into osteoclasts. These data demonstrate the relevance of PAK4 in osteoclast differentiation and the potential of PAK4 inhibitors for treating osteoclast-related disorders.
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Affiliation(s)
- Sik-Won Choi
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Jeong-Tae Yeon
- Department of Pharmacy, Sunchon National University, Suncheon, South Korea
| | - Byung Jun Ryu
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Kwang-Jin Kim
- Department of Pharmacy, Sunchon National University, Suncheon, South Korea
| | - Seong-Hee Moon
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Hyuk Lee
- Medicinal Chemistry Research Center, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Myeung Su Lee
- Division of Rheumatology, Department of Internal Medicine, Wonkwang University, Iksan, Jeonbuk, South Korea
| | - Sam Youn Lee
- Department of Cardiac and Thoracic Surgery, Wonkwang University, Iksan, Jeonbuk, South Korea
| | - Jin-Chul Heo
- Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Sang-Joon Park
- Department of Histology, College of Veterinary Medicine, Kyungpook National University, Daegu, South Korea
| | - Seong Hwan Kim
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
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Itzstein C, Coxon FP, Rogers MJ. The regulation of osteoclast function and bone resorption by small GTPases. Small GTPases 2014; 2:117-130. [PMID: 21776413 DOI: 10.4161/sgtp.2.3.16453] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/22/2011] [Accepted: 05/10/2011] [Indexed: 01/11/2023] Open
Abstract
Osteoclasts are multinucleated cells that are responsible for resorption of bone, and increased activity of these cells is associated with several common bone diseases, including postmenopausal osteoporosis. Upon adhesion to bone, osteoclasts become polarized and reorganise their cytoskeleton and membrane to form unique domains including the sealing zone (SZ), which is a dense ring of F-actin-rich podosomes delimiting the ruffled border (RB), where protons and proteases are secreted to demineralise and degrade the bone matrix, respectively. These processes are dependent on the activity of small GTPases. Rho GTPases are well known to control the organization of F-actin and adhesion structures of different cell types, affecting subsequently their migration. In osteoclasts, RhoA, Rac, Cdc42, RhoU and also Arf6 regulate podosome assembly and their organization into the SZ. By contrast, the formation of the RB involves vesicular trafficking pathways that are regulated by the Rab family of GTPases, in particular lysosomal Rab7. Finally, osteoclast survival is dependent on the activity of Ras GTPases. The correct function of almost all these GTPases is absolutely dependent on post-translational prenylation, which enables them to localize to specific target membranes. Bisphosphonate drugs, which are widely used in the treatment of bone diseases such as osteoporosis, act by preventing the prenylation of small GTPases, resulting in the loss of the SZ and RB and therefore inhibition of osteoclast activity, as well as inducing osteoclast apoptosis. In this review we summarize current understanding of the role of specific prenylated small GTPases in osteoclast polarization, function and survival.
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Affiliation(s)
- Cecile Itzstein
- Musculoskeletal Research Programme; Institute of Medical Sciences; University of Aberdeen; Aberdeen, Scotland UK
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Castillo-Pichardo L, Humphries-Bickley T, De La Parra C, Forestier-Roman I, Martinez-Ferrer M, Hernandez E, Vlaar C, Ferrer-Acosta Y, Washington AV, Cubano LA, Rodriguez-Orengo J, Dharmawardhane S. The Rac Inhibitor EHop-016 Inhibits Mammary Tumor Growth and Metastasis in a Nude Mouse Model. Transl Oncol 2014; 7:546-55. [PMID: 25389450 PMCID: PMC4225654 DOI: 10.1016/j.tranon.2014.07.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 07/14/2014] [Accepted: 07/18/2014] [Indexed: 01/19/2023] Open
Abstract
Metastatic disease still lacks effective treatments, and remains the primary cause of cancer mortality. Therefore, there is a critical need to develop better strategies to inhibit metastatic cancer. The Rho family GTPase Rac is an ideal target for anti-metastatic cancer therapy, because Rac is a key molecular switch that is activated by a myriad of cell surface receptors to promote cancer cell migration/invasion and survival. Previously, we reported the design and development of EHop-016, a small molecule compound, which inhibits Rac activity of metastatic cancer cells with an IC50 of 1 μM. EHop-016 also inhibits the activity of the Rac downstream effector p21-activated kinase (PAK), lamellipodia extension, and cell migration in metastatic cancer cells. Herein, we tested the efficacy of EHop-016 in a nude mouse model of experimental metastasis, where EHop-016 administration at 25 mg/kg body weight (BW) significantly reduced mammary fat pad tumor growth, metastasis, and angiogenesis. As quantified by UPLC MS/MS, EHop-016 was detectable in the plasma of nude mice at 17 to 23 ng/ml levels at 12 h following intraperitoneal (i.p.) administration of 10 to 25 mg/kg BW EHop-016. The EHop-016 mediated inhibition of angiogenesis In Vivo was confirmed by immunohistochemistry of excised tumors and by In Vitro tube formation assays of endothelial cells. Moreover, EHop-016 affected cell viability by down-regulating Akt and Jun kinase activities and c-Myc and Cyclin D expression, as well as increasing caspase 3/7 activities in metastatic cancer cells. In conclusion, EHop-016 has potential as an anticancer compound to block cancer progression via multiple Rac-directed mechanisms.
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Affiliation(s)
- Linette Castillo-Pichardo
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico ; Department of Pathology and Laboratory Medicine, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico
| | - Tessa Humphries-Bickley
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Columba De La Parra
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Ingrid Forestier-Roman
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Magaly Martinez-Ferrer
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Eliud Hernandez
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Cornelis Vlaar
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | | | | | - Luis A Cubano
- Department of Anatomy and Cell Biology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico
| | - Jose Rodriguez-Orengo
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Suranganie Dharmawardhane
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
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Nakagawa T, Ohta K, Kubozono K, Ishida Y, Naruse T, Takechi M, Kamata N. Zoledronate inhibits receptor activator of nuclear factor kappa-B ligand-induced osteoclast differentiation via suppression of expression of nuclear factor of activated T-cell c1 and carbonic anhydrase 2. Arch Oral Biol 2014; 60:557-65. [PMID: 25601046 DOI: 10.1016/j.archoralbio.2014.09.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/28/2014] [Indexed: 12/11/2022]
Abstract
Bisphosphonates (BPs) are widely used in the prevention of skeletal-related events (SRE), including osteoporosis, skeletal metastases of malignant tumours, and multiple myeloma. Osteonecrosis of the jaw (ONJ) is frequently reported as a major adverse effect induced by BP treatment. The receptor activator of the nuclear factor kappa-B ligand (RANKL) inhibitor, denosumab, has recently been used to prevent SRE, but the frequency of ONJ induced by denosumab is similar to that by BPs. This finding suggests that the inhibition of RANKL-mediated osteoclastogenesis may have a close relationship with the occurrence of ONJ. We therefore investigated the expression status of RANKL-inducible genes in zoledronate-treated mouse osteoclast precursor cells. The molecular targets of zoledronate in the RANKL signal pathway and additional factors associated with osteoclastogenesis were analysed by genome-wide screening. Microarray analysis identified that among 31 genes on 44 entities of RANKL-inducible genes, the mRNA expression level of two genes, i.e., nuclear factor of activated T-cells c1 (NFATc1) and carbonic anhydrase 2 (CAII), was decreased in zoledronate-treated cells. Subsequent analyses verified that these two genes were significantly silenced by zoledronate treatment and that their expression was restored following inhibition of zoledronate action by geranylgeraniol. Zoledronate inhibited RANKL-induced osteoclast differentiation by suppression of NFATc1 and CAII gene expression. Our results suggest that these genes might be common targets for zoledronate and denosumab in the mechanism underlying RANKL-induced osteoclast differentiation. A clear understanding of the common molecular mechanisms of bone-remodelling agents is thus essential for prevention of ONJ.
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Affiliation(s)
- Takayuki Nakagawa
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan.
| | - Kouji Ohta
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | - Kazumi Kubozono
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | - Yoko Ishida
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | - Takako Naruse
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | - Masaaki Takechi
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | - Nobuyuki Kamata
- Department of Oral and Maxillofacial Surgery, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
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67
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Zheng Q, Shen J. WITHDRAWN: The instability of Cdc42 network with graph-theoretic methods. Math Biosci 2014:S0025-5564(14)00145-X. [PMID: 25128657 DOI: 10.1016/j.mbs.2014.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 07/25/2014] [Accepted: 08/01/2014] [Indexed: 11/20/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor due to some inconsistencies in the manuscript. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Qianqian Zheng
- School of Mathematics and Statistics, Zhengzhou University, Zhengzhou 450000, PR China; Institute of Applied Mathematics, Xuchang University, Xuchang, Henan 461000, PR China
| | - Jianwei Shen
- Institute of Applied Mathematics, Xuchang University, Xuchang, Henan 461000, PR China
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68
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Rody WJ, Holliday LS, McHugh KP, Wallet SM, Spicer V, Krokhin O. Mass spectrometry analysis of gingival crevicular fluid in the presence of external root resorption. Am J Orthod Dentofacial Orthop 2014; 145:787-98. [PMID: 24880850 DOI: 10.1016/j.ajodo.2014.03.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 03/01/2014] [Accepted: 03/01/2014] [Indexed: 12/18/2022]
Abstract
INTRODUCTION In this study, we used liquid chromatography-mass spectrometry (LC-MS) to investigate the differences in the composition of gingival crevicular fluid between resorbing deciduous molars and nonresorbing permanent teeth. The main goal was to identify novel biomarkers associated with root resorption. METHODS Eleven children (4 boys, 7 girls) in the mixed dentition were selected to participate in this split-mouth design study, in which a deciduous second molar with radiographic evidence of root resorption served as the experimental site, and the permanent first molar on the contralateral quadrant was the control site. Gingival crevicular fluid was collected using absorbing strips. A total of 22 samples (11 root resorption, 11 control) were each analyzed with 1-dimensional LC-MS. The remaining samples were then pooled across the 11 patients and analyzed by 2-dimensional LC-MS. The output files were converted to mascot generic format, which can be used to perform protein identification with conventional search engines. RESULTS The 2-dimensional LC-MS protocol was able to identify 2789 and 2421 proteins in the control and resorption pooled samples, respectively. In this population, we detected significantly upregulated and downregulated proteins in the teeth with root resorption. Interestingly, many of these proteins are characteristically found in exosomes. CONCLUSIONS We identified novel proteins that might prove to be useful biomarkers of root resorption, individually or as part of a panel.
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Affiliation(s)
- Wellington J Rody
- Assistant professor, Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, Fla.
| | - L Shannon Holliday
- Associate professor, Department of Orthodontics, College of Dentistry, and Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Fla
| | - Kevin P McHugh
- Associate professor, Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Fla
| | - Shannon M Wallet
- Associate professor, Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Fla
| | - Victor Spicer
- Bioinformatics specialist, Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Oleg Krokhin
- Assistant professor, Department of Internal Medicine, University of Manitoba; senior scientist, Manitoba Center for Proteomics and Systems Biology, Winnipeg Manitoba, Canada
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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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Spuul P, Ciufici P, Veillat V, Leclercq A, Daubon T, Kramer IJ, Génot E. Importance of RhoGTPases in formation, characteristics, and functions of invadosomes. Small GTPases 2014; 5:e28195. [PMID: 24967648 DOI: 10.4161/sgtp.28713] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Podosomes and invadopodia (collectively known as invadosomes) are specialized plasma-membrane actin-based microdomains that combine adhesive properties with matrix degrading and/or mechanosensor activities. These organelles have been extensively studied in vitro and current concerted efforts aim at establishing their physiological relevance and subsequent association with human diseases. Proper functioning of the bone, immune, and vascular systems is likely to depend on these structures while their occurrence in cancer cells appears to be linked to tumor metastasis. The elucidation of the mechanisms driving invadosome assembly is a prerequisite to understanding their role in vivo and ultimately to controlling their functions. Adhesive and soluble ligands act via transmembrane receptors that propagate signals to the cytoskeleton via small G proteins of the Rho family, assisted by tyrosine kinases and scaffold proteins to induce invadosome formation and rearrangements. Oncogene expression and cell-cell interactions may also trigger their assembly. Manipulation of the signals that regulate invadosome formation and dynamics could therefore be a strategy to interfere with their functions in a multitude of pathological settings, such as excessive bone breakdown, infections, vascular remodeling, transendothelial diapedesis, and metastasis.
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Affiliation(s)
- Pirjo Spuul
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
| | - Paolo Ciufici
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
| | - Véronique Veillat
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
| | - Anne Leclercq
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
| | - Thomas Daubon
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
| | - IJsbrand Kramer
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
| | - Elisabeth Génot
- Université de Bordeaux; Bordeaux, France; INSERM U1045; Bordeaux, France; IECB; European Institute of Chemistry and Biology; Pessac, France
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Touaitahuata H, Blangy A, Vives V. Modulation of osteoclast differentiation and bone resorption by Rho GTPases. Small GTPases 2014; 5:e28119. [PMID: 24614674 DOI: 10.4161/sgtp.28119] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bone is a dynamic tissue constantly renewed through a regulated balance between bone formation and resorption. Excessive bone degradation by osteoclasts leads to pathological decreased bone density characteristic of osteolytic diseases such as post-menopausal osteoporosis or bone metastasis. Osteoclasts are multinucleated cells derived from hematopoietic stem cells via a complex differentiation process. Their unique ability to resorb bone is dependent on the formation of the actin-rich sealing zone. Within this adhesion structure, the plasma membrane differentiates into the ruffled border where protons and proteases are secreted to demineralize and degrade bone, respectively. On the bone surface, mature osteoclasts alternate between stationary resorptive and migratory phases. These are associated with profound actin cytoskeleton reorganization, until osteoclasts die of apoptosis. In this review, we highlight the role of Rho GTPases in all the steps of osteoclasts differentiation, function, and death and conclude on their interest as targets for treatment of osteolytic pathologies.
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Affiliation(s)
- Heiani Touaitahuata
- Montpellier University; CNRS UMR 5237; Centre de Recherche de Biochimie Macromoléculaire; Montpellier, France
| | - Anne Blangy
- Montpellier University; CNRS UMR 5237; Centre de Recherche de Biochimie Macromoléculaire; Montpellier, France
| | - Virginie Vives
- Montpellier University; CNRS UMR 5237; Centre de Recherche de Biochimie Macromoléculaire; Montpellier, France
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Abstract
The adult skeleton undergoes bone remodeling that consists of bone formation by osteoblasts and bone resorption by osteoclasts. When the amount of bone resorbed is greater than the amount of new bone formed, low bone mass results, putting individuals at increased risk for osteoporosis and osteoporotic bone fracture. Nitrogenous bisphosphonates (NBPs) are the most common first line treatment for conditions of low bone mass. NBPs reduce osteoclast bone resorption by impairing the post-translational modification of small GTPases. Small GTPases play crucial roles in the differentiation, function, and survival of osteoclasts. Understanding the roles of individual small GTPases in osteoclast biology may lead to more targeted therapies for the treatment of low bone mass. In this review, we discuss recent investigations into the in vivo effects of individual GTPase deletion in osteoclasts and the molecular roles for small GTPases in osteoclast biology.
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Franceschetti T, Kessler CB, Lee SK, Delany AM. miR-29 promotes murine osteoclastogenesis by regulating osteoclast commitment and migration. J Biol Chem 2013; 288:33347-60. [PMID: 24085298 DOI: 10.1074/jbc.m113.484568] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Osteoclast differentiation is regulated by transcriptional, post-transcriptional, and post-translational mechanisms. MicroRNAs are fundamental post-transcriptional regulators of gene expression. The function of the miR-29 (a/b/c) family in cells of the osteoclast lineage is not well understood. In primary cultures of mouse bone marrow-derived macrophages, inhibition of miR-29a, -29b, or -29c diminished formation of TRAP (tartrate-resistant acid phosphatase-positive) multinucleated osteoclasts, and the osteoclasts were smaller. Quantitative RT-PCR showed that all miR-29 family members increased during osteoclast differentiation, in concert with mRNAs for the osteoclast markers Trap (Acp5) and cathepsin K. Similar regulation was observed in the monocytic cell line RAW264.7. In stably transduced RAW264.7 cell lines expressing an inducible miR-29 competitive inhibitor (sponge construct), miR-29 knockdown impaired osteoclastic commitment and migration of pre-osteoclasts. However, miR-29 knockdown did not affect cell viability, actin ring formation, or apoptosis in mature osteoclasts. To better understand how miR-29 regulates osteoclast function, we validated miR-29 target genes using Luciferase 3'-UTR reporter assays and specific miR-29 inhibitors. We demonstrated that miR-29 negatively regulates RNAs critical for cytoskeletal organization, including Cdc42 (cell division control protein 42) and Srgap2 (SLIT-ROBO Rho GTPase-activating protein 2). Moreover, miR-29 targets RNAs associated with the macrophage lineage: Gpr85 (G protein-coupled receptor 85), Nfia (nuclear factor I/A), and Cd93. In addition, Calcr (calcitonin receptor), which regulates osteoclast survival and resorption, is a novel miR-29 target. Thus, miR-29 is a positive regulator of osteoclast formation and targets RNAs important for cytoskeletal organization, commitment, and osteoclast function. We hypothesize that miR-29 controls the tempo and amplitude of osteoclast differentiation.
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Abstract
INTRODUCTION The Rho GTPases are a family of proteins that control fundamental cellular processes in response to extracellular stimuli and internal programs. Rho GTPases function as molecular switches in which the GTP-bound proteins are active and GDP-bound proteins are inactive. This article will focus on one Rho family member, Cdc42, which is overexpressed in a number of human cancers, and which might provide new therapeutic targets in malignancies. AREAS COVERED In this article, the key regulators and effectors of Cdc42 and their molecular alterations are described. The complex interactions between the signaling cascades regulated by Cdc42 are also analyzed. EXPERT OPINION While mutations in Cdc42 have not been reported in human cancer, aberrant expression of Cdc42 has been reported in a variety of tumor types and in some instances has been correlated with poor prognosis. Recently, it has been shown that Cdc42 activation by oncogenic Ras is crucial for Ras-mediated tumorigenesis, suggesting that targeting Cdc42 or its effectors might be useful in tumors harboring activating Ras mutations.
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Affiliation(s)
- Luis E Arias-Romero
- Cancer Biology Program, Fox Chase Cancer Center , Philadelphia, PA , USA +1 215 728 5319 ; +1 215 728 3616 ;
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75
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Raman R, Kumar RS, Hinge A, Kumar S, Nayak R, Xu J, Szczur K, Cancelas JA, Filippi MD. p190-B RhoGAP regulates the functional composition of the mesenchymal microenvironment. Leukemia 2013; 27:2209-19. [PMID: 23563238 PMCID: PMC3919554 DOI: 10.1038/leu.2013.103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 03/29/2013] [Accepted: 03/29/2013] [Indexed: 12/22/2022]
Abstract
Hematopoiesis is regulated by components of the microenvironment, so-called niche. Here, we show that p190-B GTPase-activating protein (p190-B) deletion in mice causes hematopoietic failure during ontogeny, in p190-B(-/-) fetal liver and bones, and in p190-B(+/-) adult bones and spleen. These defects are non-cell autonomous, as we previously showed that transplantation of p190-B(-/-) hematopoietic cells into wild-type (WT) hosts leads to normal hematopoiesis. Coculture of mesenchymal stem (MSC)/progenitor cells and wild-type bone marrow (BM) cells reveals that p190-B(-/-) MSCs are dysfunctional in supporting hematopoiesis owing to impaired Wnt signaling. Furthermore, p190-B loss causes alteration in BM niche composition, including abnormal colony-forming unit (CFU)-fibroblast, CFU-adipocyte and CFU-osteoblast numbers. This is due to altered MSC lineage fate specification to osteoblast and adipocyte lineages. Thus, p190-B organizes a functional mesenchymal/microenvironment for normal hematopoiesis during development.
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Affiliation(s)
- R Raman
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Research Foundation, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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76
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Ke K, Sul OJ, Kim WK, Lee MH, Ko MS, Suh JH, Kim HJ, Kim SY, Park JW, Choi HS. Overexpression of developmentally regulated GTP-binding protein-2 increases bone loss. Am J Physiol Endocrinol Metab 2013; 304:E703-10. [PMID: 23360825 DOI: 10.1152/ajpendo.00517.2012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The developmentally regulated GTP-binding protein-2 (DRG2) is a novel subclass of GTP-binding proteins. Many functional characteristics of osteoclasts (OC) are associated with small GTPases. We hypothesized that DRG2 affects bone mass via modulating OC activity. Using DRG2 transgenic mice, we investigated the role of DRG2 in bone remodeling. DRG2 overexpression caused a decrease in bone mass and an increase in the number and activity of OC in vivo. DRG2 overexpression increased fusion, spreading, survival, and resorption activity of OC in vitro. Downregulation of DRG2 by siRNA decreased fusion, spreading, and survival of OC, supporting the observations found in DRG2 transgenic OC. Transgenic mature OCs were larger, with actin rings and higher ERK, Akt, Rac1 and Rho activities than wild-type OCs. Inhibition of these proteins abolished the effects of DRG2 on formation of large OCs with actin rings, implying that DRG2 affects cytoskeleton reorganization in a Rac1/Rho/ERK/Akt-dependent manner. In summary, DRG2 is associated with survival and cytoskeleton organization of OC under influence of macrophage colony-stimulating factor, and its overexpression leads to elevated bone resorptive activity of OC, resulting in bone loss.
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Affiliation(s)
- Ke Ke
- Department of Biological Sciences (BK21 Program) and the Immunomodulation Research Center, University of Ulsan, Ulsan, Korea
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77
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Feng X, Teitelbaum SL. Osteoclasts: New Insights. Bone Res 2013; 1:11-26. [PMID: 26273491 DOI: 10.4248/br201301003] [Citation(s) in RCA: 328] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/19/2013] [Indexed: 11/10/2022] Open
Abstract
Osteoclasts, the bone-resorbing cells, play a pivotal role in skeletal development and adult bone remodeling. They also participate in the pathogenesis of various bone disorders. Osteoclasts differentiate from cells of the monocyte/macrophage lineage upon stimulation of two essential factors, the monocyte/macrophage colony stimulating factor (M-CSF) and receptor activation of NF-κB ligand (RANKL). M-CSF binds to its receptor c-Fms to activate distinct signaling pathways to stimulate the proliferation and survival of osteoclast precursors and the mature cell. RANKL, however, is the primary osteoclast differentiation factor, and promotes osteoclast differentiation mainly through controlling gene expression by activating its receptor, RANK. Osteoclast function depends on polarization of the cell, induced by integrin αvβ3, to form the resorptive machinery characterized by the attachment to the bone matrix and the formation of the bone-apposed ruffled border. Recent studies have provided new insights into the mechanism of osteoclast differentiation and bone resorption. In particular, c-Fms and RANK signaling have been shown to regulate bone resorption by cross-talking with those activated by integrin αvβ3. This review discusses new advances in the understanding of the mechanisms of osteoclast differentiation and function.
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Affiliation(s)
- Xu Feng
- Department of Pathology, The University of Alabama at Birmingham , Birmingham, Alabama 35294, USA
| | - Steven L Teitelbaum
- Department of Pathology and Immunology, Washington University School of Medicine , St. Louis, Missouri 63110, USA
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Rac1 and Cdc42 GTPases regulate shear stress-driven β-catenin signaling in osteoblasts. Biochem Biophys Res Commun 2013; 433:502-7. [PMID: 23524265 DOI: 10.1016/j.bbrc.2013.03.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 03/06/2013] [Indexed: 01/29/2023]
Abstract
Beta-catenin-dependent TCF/LEF (T-cell factor/lymphocyte enhancing factor) is known to be mechanosensitive and an important regulator for promoting bone formation. However, the functional connection between TCF/LEF activity and Rho family GTPases is not well understood in osteoblasts. Herein we investigated the molecular mechanisms underlying oscillatory shear stress-induced TCF/LEF activity in MC3T3-E1 osteoblast cells using live cell imaging. We employed fluorescence resonance energy transfer (FRET)-based and green fluorescent protein (GFP)-based biosensors, which allowed us to monitor signal transduction in living cells in real time. Oscillatory (1Hz) shear stress (10 dynes/cm2) increased TCF/LEF activity and stimulated translocation of β-catenin to the nucleus with the distinct activity patterns of Rac1 and Cdc42. The shear stress-induced TCF/LEF activity was blocked by the inhibition of Rac1 and Cdc42 with their dominant negative mutants or selective drugs, but not by a dominant negative mutant of RhoA. In contrast, constitutively active Rac1 and Cdc42 mutants caused a significant enhancement of TCF/LEF activity. Moreover, activation of Rac1 and Cdc42 increased the basal level of TCF/LEF activity, while their inhibition decreased the basal level. Interestingly, disruption of cytoskeletal structures or inhibition of myosin activity did not significantly affect shear stress-induced TCF/LEF activity. Although Rac1 is reported to be involved in β-catenin in cancer cells, the involvement of Cdc42 in β-catenin signaling in osteoblasts has not been identified. Our findings in this study demonstrate that both Rac1 and Cdc42 GTPases are critical regulators in shear stress-driven β-catenin signaling in osteoblasts.
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79
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Zou W, Izawa T, Zhu T, Chappel J, Otero K, Monkley SJ, Critchley DR, Petrich BG, Morozov A, Ginsberg MH, Teitelbaum SL. Talin1 and Rap1 are critical for osteoclast function. Mol Cell Biol 2013; 33:830-44. [PMID: 23230271 PMCID: PMC3571341 DOI: 10.1128/mcb.00790-12] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/05/2012] [Indexed: 01/09/2023] Open
Abstract
To determine talin1's role in osteoclasts, we mated TLN1(fl/fl) mice with those expressing cathepsin K-Cre (CtsK-TLN1) to delete the gene in mature osteoclasts or with lysozyme M-Cre (LysM-TLN1) mice to delete TLN1 in all osteoclast lineage cells. Absence of TLN1 impairs macrophage colony-stimulating factor (M-CSF)-stimulated inside-out integrin activation and cytoskeleton organization in mature osteoclasts. Talin1-deficient precursors normally express osteoclast differentiation markers when exposed to M-CSF and receptor activator of nuclear factor κB (RANK) ligand but attach to substrate and migrate poorly, arresting their development into mature resorptive cells. In keeping with inhibited resorption, CtsK-TLN1 mice exhibit an ∼5-fold increase in bone mass. Osteoclast-specific deletion of Rap1 (CtsK-Rap1), which promotes talin/β integrin recognition, yields similar osteopetrotic mice. The fact that the osteopetrosis of CtsK-TLN1 and CtsK-Rap1 mice is substantially more severe than that of those lacking αvβ3 is likely due to added failed activation of β1 integrins. In keeping with osteoclast dysfunction, mice in whom talin is deleted late in the course of osteoclastogenesis are substantially protected from ovariectomy-induced osteoporosis and the periarticular osteolysis attending inflammatory arthritis. Thus, talin1 and Rap1 are critical for resorptive function, and their selective inhibition in mature osteoclasts retards pathological bone loss.
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Affiliation(s)
- Wei Zou
- Department of Pathology and Immunology
| | | | | | | | | | - Susan J. Monkley
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - David R. Critchley
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Brian G. Petrich
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Alexei Morozov
- Unit on Behavioral Genetics, Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Mark H. Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Steven L. Teitelbaum
- Department of Pathology and Immunology
- Department of Medicine, Division of Bone and Mineral Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
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80
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Oikawa T, Kuroda Y, Matsuo K. Regulation of osteoclasts by membrane-derived lipid mediators. Cell Mol Life Sci 2013; 70:3341-53. [PMID: 23296124 PMCID: PMC3753467 DOI: 10.1007/s00018-012-1238-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/05/2012] [Accepted: 12/10/2012] [Indexed: 12/22/2022]
Abstract
Osteoclasts are bone-resorbing cells of monocytic origin. An imbalance between bone formation and resorption can lead to osteoporosis or osteopetrosis. Osteoclastogenesis is triggered by RANKL- and IP3-induced Ca2+ influx followed by activation of NFATc1, a master transcription factor for osteoclastogenic gene regulation. During differentiation, osteoclasts undergo cytoskeletal remodeling to migrate and attach to the bone surface. Simultaneously, they fuse with each other to form multinucleated cells. These processes require PI3-kinase-dependent cytoskeletal protein activation to initiate cytoskeletal remodeling, resulting in the formation of circumferential podosomes and fusion-competent protrusions. In multinucleated osteoclasts, circumferential podosomes mature into stabilized actin rings, which enables the formation of a ruffled border where intensive membrane trafficking is executed. Membrane lipids, especially phosphoinositides, are key signaling molecules that regulate osteoclast morphology and act as second messengers and docking sites for multiple important effectors. We examine the critical roles of phosphoinositides in the signaling cascades that regulate osteoclast functions.
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Affiliation(s)
- Tsukasa Oikawa
- Laboratory of Cell and Tissue Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
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81
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Cremasco V, Decker CE, Stumpo D, Blackshear PJ, Nakayama KI, Nakayama K, Lupu TS, Graham DB, Novack DV, Faccio R. Protein kinase C-delta deficiency perturbs bone homeostasis by selective uncoupling of cathepsin K secretion and ruffled border formation in osteoclasts. J Bone Miner Res 2012; 27:2452-63. [PMID: 22806935 PMCID: PMC3498518 DOI: 10.1002/jbmr.1701] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/12/2012] [Accepted: 06/26/2012] [Indexed: 01/27/2023]
Abstract
Bone homeostasis requires stringent regulation of osteoclasts, which secrete proteolytic enzymes to degrade the bone matrix. Despite recent progress in understanding how bone resorption occurs, the mechanisms regulating osteoclast secretion, and in particular the trafficking route of cathepsin K vesicles, remain elusive. Using a genetic approach, we describe the requirement for protein kinase C-delta (PKCδ) in regulating bone resorption by affecting cathepsin K exocytosis. Importantly, PKCδ deficiency does not perturb formation of the ruffled border or trafficking of lysosomal vesicles containing the vacuolar-ATPase (v-ATPase). Mechanistically, we find that cathepsin K exocytosis is controlled by PKCδ through modulation of the actin bundling protein myristoylated alanine-rich C-kinase substrate (MARCKS). The relevance of our finding is emphasized in vivo because PKCδ-/- mice exhibit increased bone mass and are protected from pathological bone loss in a model of experimental postmenopausal osteoporosis. Collectively, our data provide novel mechanistic insights into the pathways that selectively promote secretion of cathepsin K lysosomes independently of ruffled border formation, providing evidence of the presence of multiple mechanisms that regulate lysosomal exocytosis in osteoclasts.
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Affiliation(s)
- Viviana Cremasco
- Department of Orthopaedics; Washington University School of Medicine; St. Louis, MO, 63110; USA
| | - Corinne E. Decker
- Department of Orthopaedics; Washington University School of Medicine; St. Louis, MO, 63110; USA
| | - Deborah Stumpo
- Laboratory of Signal transduction; National Institute of Environmental Health Science; Research Triangle Park, NC, 27709; USA
| | - Perry J. Blackshear
- Laboratory of Signal transduction; National Institute of Environmental Health Science; Research Triangle Park, NC, 27709; USA
| | - Keiichi I. Nakayama
- Department of Molecular and Cellular Biology; Medical Institute of Bioregulation; Kyushu University; Fukuoka, Fukuoka 812-8582; JAPAN
| | - Keiko Nakayama
- Department of Developmental Genetics; Center for Translational and Advanced Animal Research; Graduate School of Medicine; Tohoku University; Aoba-ku, Sendai 980-8575; Japan
| | - Traian S. Lupu
- Department of Orthopaedics; Washington University School of Medicine; St. Louis, MO, 63110; USA
| | - Daniel B. Graham
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis, MO, 63110; USA
| | - Deborah V. Novack
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis, MO, 63110; USA
| | - Roberta Faccio
- Department of Orthopaedics; Washington University School of Medicine; St. Louis, MO, 63110; USA
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TAK1 is essential for osteoclast differentiation and is an important modulator of cell death by apoptosis and necroptosis. Mol Cell Biol 2012; 33:582-95. [PMID: 23166301 DOI: 10.1128/mcb.01225-12] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Transforming growth factor β (TGF-β)-activated kinase 1 (TAK1), a mitogen-activated protein 3 (MAP3) kinase, plays an essential role in inflammation by activating the IκB kinase (IKK)/nuclear factor κB (NF-κB) and stress kinase (p38 and c-Jun N-terminal kinase [JNK]) pathways in response to many stimuli. The tumor necrosis factor (TNF) superfamily member receptor activator of NF-κB ligand (RANKL) regulates osteoclastogenesis through its receptor, RANK, and the signaling adaptor TRAF6. Because TAK1 activation is mediated through TRAF6 in the interleukin 1 receptor (IL-1R) and toll-like receptor (TLR) pathways, we sought to investigate the consequence of TAK1 deletion in RANKL-mediated osteoclastogenesis. We generated macrophage colony-stimulating factor (M-CSF)-derived monocytes from the bone marrow of mice with TAK1 deletion in the myeloid lineage. Unexpectedly, TAK1-deficient monocytes in culture died rapidly but could be rescued by retroviral expression of TAK1, inhibition of receptor-interacting protein 1 (RIP1) kinase activity with necrostatin-1, or simultaneous genetic deletion of TNF receptor 1 (TNFR1). Further investigation using TAK1-deficient mouse embryonic fibroblasts revealed that TNF-α-induced cell death was abrogated by the simultaneous inhibition of caspases and knockdown of RIP3, suggesting that TAK1 is an important modulator of both apoptosis and necroptosis. Moreover, TAK1-deficient monocytes rescued from programmed cell death did not form mature osteoclasts in response to RANKL, indicating that TAK1 is indispensable to RANKL-induced osteoclastogenesis. To our knowledge, we are the first to report that mice in which TAK1 has been conditionally deleted in osteoclasts develop osteopetrosis.
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83
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Charles JF, Coury F, Sulyanto R, Sitara D, Wu J, Brady N, Tsang K, Sigrist K, Tollefsen DM, He L, Storm D, Aliprantis AO. The collection of NFATc1-dependent transcripts in the osteoclast includes numerous genes non-essential to physiologic bone resorption. Bone 2012; 51:902-12. [PMID: 22985540 PMCID: PMC3457000 DOI: 10.1016/j.bone.2012.08.113] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/30/2012] [Accepted: 08/06/2012] [Indexed: 01/15/2023]
Abstract
Osteoclasts are specialized secretory cells of the myeloid lineage important for normal skeletal homeostasis as well as pathologic conditions of bone including osteoporosis, inflammatory arthritis and cancer metastasis. Differentiation of these multinucleated giant cells from precursors is controlled by the cytokine RANKL, which through its receptor RANK initiates a signaling cascade culminating in the activation of transcriptional regulators which induce the expression of the bone degradation machinery. The transcription factor nuclear factor of activated T-cells c1 (NFATc1) is the master regulator of this process and in its absence osteoclast differentiation is aborted both in vitro and in vivo. Differential mRNA expression analysis by microarray is used to identify genes of potential physiologic relevance across nearly all biologic systems. We compared the gene expression profile of murine wild-type and NFATc1-deficient osteoclast precursors stimulated with RANKL and identified that the majority of the known genes important for osteoclastic bone resorption require NFATc1 for induction. Here, five novel RANKL-induced, NFATc1-dependent transcripts in the osteoclast are described: Nhedc2, Rhoc, Serpind1, Adcy3 and Rab38. Despite reasonable hypotheses for the importance of these molecules in the bone resorption pathway and their dramatic induction during differentiation, the analysis of mice with mutations in these genes failed to reveal a function in osteoclast biology. Compared to littermate controls, none of these mutants demonstrated a skeletal phenotype in vivo or alterations in osteoclast differentiation or function in vitro. These data highlight the need for rigorous validation studies to complement expression profiling results before functional importance can be assigned to highly regulated genes in any biologic process.
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Affiliation(s)
- Julia F. Charles
- Department of Medicine, Division of Rheumatology, Allergy and Immunology, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Fabienne Coury
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Rosalyn Sulyanto
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
- OCC Dentistry, Columbus, OH, USA
| | - Despina Sitara
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
- New York University College of Dentistry, New York, NY, USA
| | - Jing Wu
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
- China Novartis Institutes for BioMedical Research Co., Shanghai 201203, China
| | - Nicholas Brady
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Laboratory Medicine and Pathology and Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Kelly Tsang
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
| | - Kirsten Sigrist
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Douglas M. Tollefsen
- Division of Hematology, Washington University School of Medicine, St. Louis, MO, USA
| | - Li He
- Division of Hematology, Washington University School of Medicine, St. Louis, MO, USA
| | - Daniel Storm
- Department of Pharmacology, University of Washington Medical School, Seattle, WA, USA
| | - Antonios O. Aliprantis
- Department of Medicine, Division of Rheumatology, Allergy and Immunology, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
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84
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Garbe AI, Roscher A, Schüler C, Lutter AH, Glösmann M, Bernhardt R, Chopin M, Hempel U, Hofbauer LC, Rammelt S, Egerbacher M, Erben RG, Jessberger R. Regulation of bone mass and osteoclast function depend on the F-actin modulator SWAP-70. J Bone Miner Res 2012; 27:2085-96. [PMID: 22648978 DOI: 10.1002/jbmr.1670] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bone remodeling involves tightly regulated bone-resorbing osteoclasts and bone-forming osteoblasts. Determining osteoclast function is central to understanding bone diseases such as osteoporosis and osteopetrosis. Here, we report a novel function of the F-actin binding and regulatory protein SWAP-70 in osteoclast biology. F-actin ring formation, cell morphology, and bone resorption are impaired in Swap-70(-/-) osteoclasts, whereas the expression of osteoclast differentiation markers induced in vitro by macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL) remains unaffected. Swap-70(-/-) mice develop osteopetrosis with increased bone mass, abnormally dense bone, and impaired osteoclast function. Ectopic expression of SWAP-70 in Swap-70(-/-) osteoclasts in vitro rescues their deficiencies in bone resorption and F-actin ring formation. Rescue requires a functional pleckstrin homology (PH) domain, known to support membrane localization of SWAP-70, and the F-actin binding domain. Transplantation of SWAP-70-proficient bone marrow into Swap-70(-/-) mice restores osteoclast resorption capacity in vivo. The identification of the role of SWAP-70 in promoting osteoclast function through modulating membrane-proximal F-actin rearrangements reveals a new pathway to control osteoclasts and bone homeostasis.
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Affiliation(s)
- Annette I Garbe
- Institute of Physiological Chemistry, Dresden University of Technology, Dresden, Germany.
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85
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Su X, Floyd DH, Hughes A, Xiang J, Schneider JG, Uluckan O, Heller E, Deng H, Zou W, Craft CS, Wu K, Hirbe AC, Grabowska D, Eagleton MC, Townsley S, Collins L, Piwnica-Worms D, Steinberg TH, Novack DV, Conley PB, Hurchla MA, Rogers M, Weilbaecher KN. The ADP receptor P2RY12 regulates osteoclast function and pathologic bone remodeling. J Clin Invest 2012; 122:3579-92. [PMID: 22996695 DOI: 10.1172/jci38576] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 07/26/2012] [Indexed: 12/16/2022] Open
Abstract
The adenosine diphosphate (ADP) receptor P2RY12 (purinergic receptor P2Y, G protein coupled, 12) plays a critical role in platelet aggregation, and P2RY12 inhibitors are used clinically to prevent cardiac and cerebral thrombotic events. Extracellular ADP has also been shown to increase osteoclast (OC) activity, but the role of P2RY12 in OC biology is unknown. Here, we examined the role of mouse P2RY12 in OC function. Mice lacking P2ry12 had decreased OC activity and were partially protected from age-associated bone loss. P2ry12-/- OCs exhibited intact differentiation markers, but diminished resorptive function. Extracellular ADP enhanced OC adhesion and resorptive activity of WT, but not P2ry12-/-, OCs. In platelets, ADP stimulation of P2RY12 resulted in GTPase Ras-related protein (RAP1) activation and subsequent αIIbβ3 integrin activation. Likewise, we found that ADP stimulation induced RAP1 activation in WT and integrin β3 gene knockout (Itgb3-/-) OCs, but its effects were substantially blunted in P2ry12-/- OCs. In vivo, P2ry12-/- mice were partially protected from pathologic bone loss associated with serum transfer arthritis, tumor growth in bone, and ovariectomy-induced osteoporosis: all conditions associated with increased extracellular ADP. Finally, mice treated with the clinical inhibitor of P2RY12, clopidogrel, were protected from pathologic osteolysis. These results demonstrate that P2RY12 is the primary ADP receptor in OCs and suggest that P2RY12 inhibition is a potential therapeutic target for pathologic bone loss.
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Affiliation(s)
- Xinming Su
- Department of Medicine, Division of Oncology, Washington University in St. Louis School of Medicine, St. Louis, Missouri 63110, USA
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86
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Rho GTPase function in development: How in vivo models change our view. Exp Cell Res 2012; 318:1779-87. [DOI: 10.1016/j.yexcr.2012.05.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/07/2012] [Accepted: 05/10/2012] [Indexed: 12/16/2022]
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87
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Chung YH, Yoon SY, Choi B, Sohn DH, Yoon KH, Kim WJ, Kim DH, Chang EJ. Microtubule-associated protein light chain 3 regulates Cdc42-dependent actin ring formation in osteoclast. Int J Biochem Cell Biol 2012; 44:989-97. [PMID: 22465708 DOI: 10.1016/j.biocel.2012.03.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 03/07/2012] [Accepted: 03/13/2012] [Indexed: 01/07/2023]
Abstract
Microtubule-associated protein 1 light chain-3 (LC3) plays a critical role in autophagosome formation during autophagy; however, its potential alternative functions remain largely unexplored. Here we demonstrate a discrete role for LC3 in osteoclast, a specialized bone-resorbing cell that requires a dynamic microtubule network for its activity. We found that an increase in the conversion of soluble LC3-I to lipid-bound LC3-II in mature osteoclast was correlated with osteoclast activity, but not with autophagic activity. Knockdown of LC3 using small interfering RNA did not affect TRAP-positive multinucleated cell formation, but suppressed actin ring formation, cathepsin K release, and the subsequent bone-resorbing capacity of osteoclasts. LC3 mediated this function by associating with microtubules and regulating Cdc42 activity. More importantly, LC3-II protein levels were reduced by the Atg5 knockdown, and this knockdown led to decrease in Cdc42 activity, indicating that LC3-II is critical for Cdc42 activity. Overexpression of a constitutively active form of Cdc42 partially rescued the phenotype induced by LC3 knockdown. Our results demonstrate that LC3 contributes to the regulatory link between the microtubule and Cdc42 involved in bone-resorbing activity, providing evidence for a role for LC3 in mediating diverse cellular functions beyond its role as an autophagy protein.
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Affiliation(s)
- Yeon-Ho Chung
- Department of Medicine, Graduate School, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea
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88
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Aizawa R, Yamada A, Suzuki D, Iimura T, Kassai H, Harada T, Tsukasaki M, Yamamoto G, Tachikawa T, Nakao K, Yamamoto M, Yamaguchi A, Aiba A, Kamijo R. Cdc42 is required for chondrogenesis and interdigital programmed cell death during limb development. Mech Dev 2012; 129:38-50. [PMID: 22387309 DOI: 10.1016/j.mod.2012.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 02/16/2012] [Accepted: 02/16/2012] [Indexed: 12/20/2022]
Abstract
Cdc42, a member of the Rho subfamily of small GTPases, is known to be a regulator of multiple cellular functions, including cytoskeletal organization, cell migration, proliferation, and apoptosis. However, its tissue-specific roles, especially in mammalian limb development, remain unclear. To investigate the physiological function of Cdc42 during limb development, we generated limb bud mesenchyme-specific inactivated Cdc42 (Cdc42(fl/fl); Prx1-Cre) mice. Cdc42(fl/fl); Prx1-Cre mice demonstrated short limbs and body, abnormal calcification of the cranium, cleft palate, disruption of the xiphoid process, and syndactyly. Severe defects were also found in long bone growth plate cartilage, characterized by loss of columnar organization of chondrocytes, and thickening and massive accumulation of hypertrophic chondrocytes, resulting in delayed endochondral bone formation associated with reduced bone growth. In situ hybridization analysis revealed that expressions of Col10 and Mmp13 were reduced in non-resorbed hypertrophic cartilage, indicating that deletion of Cdc42 inhibited their terminal differentiation. Syndactyly in Cdc42(fl/fl); Prx1-Cre mice was caused by fusion of metacarpals and a failure of interdigital programmed cell death (ID-PCD). Whole mount in situ hybridization analysis of limb buds showed that the expression patterns of Sox9 were ectopic, while those of Bmp2, Msx1, and Msx2, known to promote apoptosis in the interdigital mesenchyme, were down-regulated. These results demonstrate that Cdc42 is essential for chondrogenesis and ID-PCD during limb development.
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Affiliation(s)
- Ryo Aizawa
- Department of Biochemistry, School of Dentistry, Showa University, Shinagawa-ku, Tokyo 142-8555, Japan
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89
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Otero K, Shinohara M, Zhao H, Cella M, Gilfillan S, Colucci A, Faccio R, Ross FP, Teitelbaum SL, Takayanagi H, Colonna M. TREM2 and β-catenin regulate bone homeostasis by controlling the rate of osteoclastogenesis. THE JOURNAL OF IMMUNOLOGY 2012; 188:2612-21. [PMID: 22312126 DOI: 10.4049/jimmunol.1102836] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
TREM2 is an immunoreceptor expressed on osteoclasts (OC) and microglia that transmits intracellular signals through the adaptor DAP12. Individuals with genetic mutations inactivating TREM2 or DAP12 develop the Nasu-Hakola disease (NHD) with cystic-like lesions of the bone and brain demyelination that lead to fractures and presenile dementia. The mechanisms of this disease are poorly understood. In this study, we report that TREM2-deficient mice have an osteopenic phenotype reminiscent of NHD. In vitro, lack of TREM2 impairs proliferation and β-catenin activation in osteoclast precursors (OcP) in response to M-CSF. This defect results in accelerated differentiation of OcP into mature OC. Corroborating the importance of a balanced proliferation and differentiation of OcP for bone homeostasis, we show that conditional deletion of β-catenin in OcP also results in reduced OcP proliferation and accelerated osteoclastogenesis in vitro as well as osteopenia in vivo. These results reveal that TREM2 regulates the rate of osteoclastogenesis and provide a mechanism for the bone pathology in NHD.
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Affiliation(s)
- Karel Otero
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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90
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Abstract
The osteoclast cytoskeleton is a unique structure that polarizes the cell's resorptive machinery to the bone-cell interface where it creates an isolated resorptive microenvironment consisting of an actin ring surrounding a ruffled border. This polarization process occurs under the aegis of the α(v) β(3) integrin in collaboration with the M-CSF receptor, c-Fms. When occupied, α(v) β(3) activates a canonical signaling complex consisting of c-Src, Syk, Dap12, Slp76, Vav 3, and Rac that permits the cell to spread and form actin rings. Generation of the ruffled border, the cell's resorptive organelle, is an exocytic process wherein synaptotagmin VII mediates fusion of secretory lysosomes to the bone-apposed plasma membrane. Absence of any component of this signaling pathway compromises osteoclast cytoskeletal organization and abridges bone resorption.
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Affiliation(s)
- Steven L Teitelbaum
- Departments of Pathology and Immunology, and Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
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91
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Abstract
Historically, in vitro culturing of primary osteoclasts involved co-culturing of mononuclear monocytes with bone marrow stromal cells, thereby providing the cytokines required for osteoclast formation and multinucleation. Since the identification and cloning of receptor activator of nuclear factor kappa B ligand (RANKL), culturing primary osteoclasts in vitro has become much simplified. It has become apparent that the actin cytoskeleton is extremely important for the osteoclast, not only in terms of structural support, but also for adhesion, polarization, and migration. Rho family GTPases are key regulators of the actin cytoskeleton. In this chapter, we describe simple techniques in culturing primary osteoclasts from murine bone marrow cells, evaluating the activation states of Rho GTPases in osteoclasts, measuring the migratory abilities of monocytes, and introducing proteins of interest into osteoclasts using the TAT construct.
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Affiliation(s)
- Roland Leung
- Matrix Dynamics Group, University of Toronto, Toronto, ON, Canada
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92
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Croke M, Ross FP, Korhonen M, Williams DA, Zou W, Teitelbaum SL. Rac deletion in osteoclasts causes severe osteopetrosis. J Cell Sci 2011; 124:3811-21. [PMID: 22114304 PMCID: PMC3225269 DOI: 10.1242/jcs.086280] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2011] [Indexed: 02/04/2023] Open
Abstract
Cdc42 mediates bone resorption principally by stimulating osteoclastogenesis. Whether its sister GTPase, Rac, meaningfully impacts upon the osteoclast and, if so, by what means, is unclear. We find that whereas deletion of Rac1 or Rac2 alone has no effect, variable reduction of Rac1 in osteoclastic cells of Rac2(-/-) mice causes severe osteopetrosis. Osteoclasts lacking Rac1 and Rac2 in combination (Rac double-knockout, RacDKO), fail to effectively resorb bone. By contrast, osteoclasts are abundant in RacDKO osteopetrotic mice and, unlike those deficient in Cdc42, express the maturation markers of the cells normally. Hence, the osteopetrotic lesion of RacDKO mice largely reflects impaired function, and not arrested differentiation, of the resorptive polykaryon. The dysfunction of RacDKO osteoclasts represents failed cytoskeleton organization as evidenced by reduced motility of the cells and their inability to spread or generate the key resorptive organelles (i.e. actin rings and ruffled borders), which is accompanied by abnormal Arp3 distribution. The cytoskeleton-organizing capacity of Rac1 is mediated through its 20-amino-acid effector domain. Thus, Rac1 and Rac2 are mutually compensatory. Unlike Cdc42 deficiency, their combined absence does not impact upon differentiation but promotes severe osteopetrosis by dysregulating the osteoclast cytoskeleton.
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Affiliation(s)
- Monica Croke
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
| | - F. Patrick Ross
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
| | | | - David A. Williams
- Division of Hematology/Oncology, Children's Hospital Boston, Boston, MA 02115, USA
| | - Wei Zou
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
| | - Steven L. Teitelbaum
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
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93
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Ye S, Fowler TW, Pavlos NJ, Ng PY, Liang K, Feng Y, Zheng M, Kurten R, Manolagas SC, Zhao H. LIS1 regulates osteoclast formation and function through its interactions with dynein/dynactin and Plekhm1. PLoS One 2011; 6:e27285. [PMID: 22073305 PMCID: PMC3207863 DOI: 10.1371/journal.pone.0027285] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 10/13/2011] [Indexed: 11/19/2022] Open
Abstract
Microtubule organization and lysosomal secretion are both critical for the activation and function of osteoclasts, highly specialized polykaryons that are responsible for bone resorption and skeletal homeostasis. Here, we have identified a novel interaction between microtubule regulator LIS1 and Plekhm1, a lysosome-associated protein implicated in osteoclast secretion. Decreasing LIS1 expression by shRNA dramatically attenuated osteoclast formation and function, as shown by a decreased number of mature osteoclasts differentiated from bone marrow macrophages, diminished resorption pits formation, and reduced level of CTx-I, a bone resorption marker. The ablated osteoclast formation in LIS1-depleted macrophages was associated with a significant decrease in macrophage proliferation, osteoclast survival and differentiation, which were caused by reduced activation of ERK and AKT by M-CSF, prolonged RANKL-induced JNK activation and declined expression of NFAT-c1, a master transcription factor of osteoclast differentiation. Consistent with its critical role in microtubule organization and dynein function in other cell types, we found that LIS1 binds to and colocalizes with dynein in osteoclasts. Loss of LIS1 led to disorganized microtubules and aberrant dynein function. More importantly, the depletion of LIS1 in osteoclasts inhibited the secretion of Cathepsin K, a crucial lysosomal hydrolase for bone degradation, and reduced the motility of osteoclast precursors. These results indicate that LIS1 is a previously unrecognized regulator of osteoclast formation, microtubule organization, and lysosomal secretion by virtue of its ability to modulate dynein function and Plekhm1.
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Affiliation(s)
- Shiqiao Ye
- Center for Osteoporosis and Metabolic Bone Diseases, Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, United States of America
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94
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Zou W, Greenblatt MB, Shim JH, Kant S, Zhai B, Lotinun S, Brady N, Hu DZ, Gygi SP, Baron R, Davis RJ, Jones D, Glimcher LH. MLK3 regulates bone development downstream of the faciogenital dysplasia protein FGD1 in mice. J Clin Invest 2011; 121:4383-92. [PMID: 21965325 PMCID: PMC3204846 DOI: 10.1172/jci59041] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 08/24/2011] [Indexed: 12/28/2022] Open
Abstract
Mutations in human FYVE, RhoGEF, and PH domain-containing 1 (FGD1) cause faciogenital dysplasia (FGDY; also known as Aarskog syndrome), an X-linked disorder that affects multiple skeletal structures. FGD1 encodes a guanine nucleotide exchange factor (GEF) that specifically activates the Rho GTPase CDC42. However, the mechanisms by which mutations in FGD1 affect skeletal development are unknown. Here, we describe what we believe to be a novel signaling pathway in osteoblasts initiated by FGD1 that involves the MAP3K mixed-lineage kinase 3 (MLK3). We observed that MLK3 functions downstream of FGD1 to regulate ERK and p38 MAPK, which in turn phosphorylate and activate the master regulator of osteoblast differentiation, Runx2. Mutations in FGD1 found in individuals with FGDY ablated its ability to activate MLK3. Consistent with our description of this pathway and the phenotype of patients with FGD1 mutations, mice with a targeted deletion of Mlk3 displayed multiple skeletal defects, including dental abnormalities, deficient calvarial mineralization, and reduced bone mass. Furthermore, mice with knockin of a mutant Mlk3 allele that is resistant to activation by FGD1/CDC42 displayed similar skeletal defects, demonstrating that activation of MLK3 specifically by FGD1/CDC42 is important for skeletal mineralization. Thus, our results provide a putative biochemical mechanism for the skeletal defects in human FGDY and suggest that modulating MAPK signaling may benefit these patients.
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MESH Headings
- Animals
- Bone Development/genetics
- Bone Development/physiology
- Disease Models, Animal
- Dwarfism/genetics
- Dwarfism/pathology
- Dwarfism/physiopathology
- Enzyme Activation
- Face/abnormalities
- Face/pathology
- Face/physiopathology
- Female
- Gene Knock-In Techniques
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/pathology
- Genetic Diseases, X-Linked/physiopathology
- Genitalia, Male/abnormalities
- Genitalia, Male/pathology
- Genitalia, Male/physiopathology
- Guanine Nucleotide Exchange Factors/genetics
- Guanine Nucleotide Exchange Factors/physiology
- Hand Deformities, Congenital/genetics
- Hand Deformities, Congenital/pathology
- Hand Deformities, Congenital/physiopathology
- Heart Defects, Congenital/genetics
- Heart Defects, Congenital/pathology
- Heart Defects, Congenital/physiopathology
- Humans
- MAP Kinase Kinase Kinases/deficiency
- MAP Kinase Kinase Kinases/genetics
- MAP Kinase Kinase Kinases/physiology
- MAP Kinase Signaling System
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Mutant Strains
- Mutation
- Osteoblasts/pathology
- Osteoblasts/physiology
- Proteins/genetics
- Proteins/physiology
- cdc42 GTP-Binding Protein/metabolism
- p38 Mitogen-Activated Protein Kinases/metabolism
- Mitogen-Activated Protein Kinase Kinase Kinase 11
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Affiliation(s)
- Weiguo Zou
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Matthew B. Greenblatt
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Jae-Hyuck Shim
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Shashi Kant
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Bo Zhai
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Sutada Lotinun
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Nicholas Brady
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Dorothy Zhang Hu
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Steven P. Gygi
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Roland Baron
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Roger J. Davis
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Dallas Jones
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
| | - Laurie H. Glimcher
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Department of Medicine, Harvard Medical School, and Ragon Institute of MGH, Harvard and MIT, Boston, Massachusetts, USA.
Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
Department of Oral Medicine Infection and Immunity, Harvard Dental School, Boston, Massachusetts, USA
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95
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The role of atypical protein kinase C in CSF-1-dependent Erk activation and proliferation in myeloid progenitors and macrophages. PLoS One 2011; 6:e25580. [PMID: 22028782 PMCID: PMC3196503 DOI: 10.1371/journal.pone.0025580] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 09/05/2011] [Indexed: 12/05/2022] Open
Abstract
Colony stimulating factor-1 (CSF-1 or M-CSF) is the major physiological regulator of the proliferation, differentiation and survival of cells of the mononuclear phagocyte lineage. CSF-1 binds to a receptor tyrosine kinase, the CSF-1 receptor (CSF-1R). Multiple pathways are activated downstream of the CSF-1R; however, it is not clear which pathways regulate proliferation and survival. Here, we investigated the role of atypical protein kinase Cs (PKCζ) in a myeloid progenitor cell line that expressed CSF-1R (32D.R) and in primary murine bone marrow derived macrophages (BMMs). In 32D.R cells, CSF-1 induced the phosphorylation of PKCζ and increased its kinase activity. PKC inhibitors and transfections with mutant PKCs showed that optimal CSF-1-dependent Erk activation and proliferation depended on the activity of PKCζ. We previously reported that CSF-1 activated the Erk pathway through an A-Raf-dependent and an A-Raf independent pathway (Lee and States, Mol. Cell. Biol.18, 6779). PKC inhibitors did not affect CSF-1 induced Ras and A-Raf activity but markedly reduced MEK and Erk activity, implying that PKCζ regulated the CSF-1-Erk pathway at the level of MEK. PKCζ has been implicated in activating the NF-κB pathway. However, CSF-1 promoted proliferation in an NF-κB independent manner. We established stable 32D.R cell lines that overexpressed PKCζ. Overexpression of PKCζ increased the intensity and duration of CSF-1 induced Erk activity and rendered cells more responsive to CSF-1 mediated proliferation. In contrast to 32D.R cells, PKCζ inhibition in BMMs had only a modest effect on proliferation. Moreover, PKCζ -specific and pan-PKC inhibitors induced a paradoxical increase in MEK-Erk phosphorylation suggesting that PKCs targeted a common negative regulatory step upstream of MEK. Our results demonstrated that CSF-1 dependent Erk activation and proliferation are regulated differentially in progenitors and differentiated cells.
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96
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Akiyama T, Tanaka S. Bim: guardian of tissue homeostasis and critical regulator of the immune system, tumorigenesis and bone biology. Arch Immunol Ther Exp (Warsz) 2011; 59:277-87. [PMID: 21633919 DOI: 10.1007/s00005-011-0126-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 01/11/2011] [Indexed: 12/16/2022]
Abstract
One of the most important roles of apoptosis is the maintenance of tissue homeostasis. Impairment of apoptosis leads to a number of pathological conditions. In response to apoptotic signals, various proteins are activated in a pathway and signal-specific manner. Recently, the pro-apoptotic molecule Bim has attracted increasing attention as a pivotal regulator of tissue homeostasis. The Bim expression level is strictly controlled in both transcriptional and post-transcriptional levels. This control is dependent on cell, tissue and apoptotic stimuli. The phenotype of Bim-deficient mice is a systemic lupus erythematosus-like autoimmune disease with an abnormal accumulation of hematopoietic cells. Bim is thus a critical regulator of hematopoietic cells and immune system. Further studies have revealed the critical roles of Bim in various normal and pathological conditions, including bone homeostasis and tumorigenesis. The current understanding of Bim signaling and roles in the maintenance of tissue homeostasis is reviewed in this paper, focusing on the immune system, bone biology and tumorigenesis to illustrate the diversified role of Bim.
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Affiliation(s)
- Toru Akiyama
- Department of Orthopaedic Surgery, Saitama Medical Center, Jichi Medical University, Omiya-ku, Saitama, Japan
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97
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98
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Melendez J, Grogg M, Zheng Y. Signaling role of Cdc42 in regulating mammalian physiology. J Biol Chem 2010; 286:2375-81. [PMID: 21115489 DOI: 10.1074/jbc.r110.200329] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cdc42 is a member of the Rho GTPase family of intracellular molecular switches regulating multiple signaling pathways involved in actomyosin organization and cell proliferation. Knowledge of its signaling function in mammalian cells came mostly from studies using the dominant-negative or constitutively active mutant overexpression approach in the past 2 decades. Such an approach imposes a number of experimental limitations related to specificity, dosage, and/or clonal variability. Recent studies by conditional gene targeting of cdc42 in mice have revealed its tissue- and cell type-specific role and provide definitive information of the physiological signaling functions of Cdc42 in vivo.
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Affiliation(s)
- Jaime Melendez
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Research Foundation, University of Cincinnati, Cincinnati, Ohio 45229, USA
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99
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