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Werbenko E, de Gorter DJJ, Kleimann S, Beckmann D, Waltereit-Kracke V, Reinhardt J, Geers F, Paruzel P, Hansen U, Pap T, Stradal TEB, Dankbar B. Hem1 is essential for ruffled border formation in osteoclasts and efficient bone resorption. Sci Rep 2024; 14:8109. [PMID: 38582757 PMCID: PMC10998871 DOI: 10.1038/s41598-024-58110-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/25/2024] [Indexed: 04/08/2024] Open
Abstract
Bone resorption is highly dependent on the dynamic rearrangement of the osteoclast actin cytoskeleton to allow formation of actin rings and a functional ruffled border. Hem1 is a hematopoietic-specific subunit of the WAVE-complex which regulates actin polymerization and is crucial for lamellipodia formation in hematopoietic cell types. However, its role in osteoclast differentiation and function is still unknown. Here, we show that although the absence of Hem1 promotes osteoclastogenesis, the ability of Hem1-/- osteoclasts to degrade bone was severely impaired. Global as well as osteoclast-specific deletion of Hem1 in vivo revealed increased femoral trabecular bone mass despite elevated numbers of osteoclasts in vivo. We found that the resorption defect derived from the morphological distortion of the actin-rich sealing zone and ruffled border deformation in Hem1-deficient osteoclasts leading to impaired vesicle transport and increased intracellular acidification. Collectively, our data identify Hem1 as a yet unknown key player in bone remodeling by regulating ruffled border formation and consequently the resorptive capacity of osteoclasts.
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Affiliation(s)
- Eugenie Werbenko
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - David J J de Gorter
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Simon Kleimann
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Denise Beckmann
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Vanessa Waltereit-Kracke
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Julia Reinhardt
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Fabienne Geers
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Peter Paruzel
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Uwe Hansen
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Thomas Pap
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany
| | - Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Berno Dankbar
- Institute of Musculoskeletal Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D3, 48149, Muenster, Germany.
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2
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Ahmed TA, Ahmed SM, Elkhenany H, El-Desouky MA, Magdeldin S, Osama A, Anwar AM, Mohamed IK, Abdelgawad ME, Hanna DH, El-Badri N. The cross talk between type II diabetic microenvironment and the regenerative capacities of human adipose tissue-derived pericytes: a promising cell therapy. Stem Cell Res Ther 2024; 15:36. [PMID: 38331889 PMCID: PMC10854071 DOI: 10.1186/s13287-024-03643-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 01/21/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND Pericytes (PCs) are multipotent contractile cells that wrap around the endothelial cells (ECs) to maintain the blood vessel's functionality and integrity. The hyperglycemia associated with Type 2 diabetes mellitus (T2DM) was shown to impair the function of PCs and increase the risk of diabetes complications. In this study, we aimed to investigate the deleterious effect of the diabetic microenvironment on the regenerative capacities of human PCs. METHODS PCs isolated from human adipose tissue were cultured in the presence or absence of serum collected from diabetic patients. The functionality of PCs was analyzed after 6, 14, and 30 days. RESULTS Microscopic examination of PCs cultured in DS (DS-PCs) showed increased aggregate formation and altered surface topography with hyperbolic invaginations. Compared to PCs cultured in normal serum (NS-PCs), DS-PCs showed more fragmented mitochondria and thicker nuclear membrane. DS caused impaired angiogenic differentiation of PCs as confirmed by tube formation, decreased VEGF-A and IGF-1 gene expression, upregulated TSP1, PF4, actin-related protein 2/3 complex, and downregulated COL21A1 protein expression. These cells suffered more pronounced apoptosis and showed higher expression of Clic4, apoptosis facilitator BCl-2-like protein, serine/threonine protein phosphatase, and caspase-7 proteins. DS-PCs showed dysregulated DNA repair genes CDKN1A, SIRT1, XRCC5 TERF2, and upregulation of the pro-inflammatory genes ICAM1, IL-6, and TNF-α. Further, DS-treated cells also showed disruption in the expression of the focal adhesion and binding proteins TSP1, TGF-β, fibronectin, and PCDH7. Interestingly, DS-PCs showed resistance mechanisms upon exposure to diabetic microenvironment by maintaining the intracellular reactive oxygen species (ROS) level and upregulation of extracellular matrix (ECM) organizing proteins as vinculin, IQGAP1, and tubulin beta chain. CONCLUSION These data showed that the diabetic microenvironment exert a deleterious effect on the regenerative capacities of human adipose tissue-derived PCs, and may thus have possible implications on the vascular complications of T2DM. Nevertheless, PCs have shown remarkable protective mechanisms when initially exposed to DS and thus they could provide a promising cellular therapy for T2DM.
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Affiliation(s)
- Toka A Ahmed
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12582, Egypt
- Egypt Center for Research and Regenerative Medicine (ECRRM), Cairo, Egypt
| | - Sara M Ahmed
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12582, Egypt
| | - Hoda Elkhenany
- Department of Surgery, Faculty of Veterinary Medicine, Alexandria University, Alexandria, 22785, Egypt
| | - Mohamed A El-Desouky
- Department of Chemistry, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Sameh Magdeldin
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo, 57357, Egypt
- Department of Physiology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt
| | - Aya Osama
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo, 57357, Egypt
| | - Ali Mostafa Anwar
- Proteomics and Metabolomics Research Program, Basic Research Department, Children's Cancer Hospital, Cairo, 57357, Egypt
| | - Ihab K Mohamed
- Department of Zoology, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Mohamed Essameldin Abdelgawad
- Biochemistry and Molecular Biotechnology Division, Chemistry Department, Faculty of Science, Innovative Cellular Microenvironment Optimization Platform (ICMOP), Precision Therapy Unit, Helwan University, Cairo, Egypt
- The Egyptian Network of Bioinformatics "BioNetMasr", Cairo, Egypt
| | - Demiana H Hanna
- Department of Chemistry, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Nagwa El-Badri
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, October Gardens, 6th of October City, Giza, 12582, Egypt.
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3
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Qureshi T, Desale SE, Chidambaram H, Chinnathambi S. Understanding Actin Remodeling in Neuronal Cells Through Podosomes. Methods Mol Biol 2024; 2761:257-266. [PMID: 38427242 DOI: 10.1007/978-1-0716-3662-6_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Cytoskeletal dysregulation forms an important aspect of many neurodegenerative diseases such as Alzheimer's disease. Cytoskeletal functions require the dynamic activity of the cytoskeletal proteins-actin, tubulin, and the associated proteins. One of such important phenomena is that of actin remodeling, which helps the cell to migrate, navigate, and interact with extracellular materials. Podosomes are complex actin-rich cytoskeletal structures, abundant in proteins that interact and degrade the extracellular matrix, enabling cells to displace and migrate. The formation of podosomes requires extensive actin networks and remodeling. Here we present a novel immunofluorescence-based approach to study actin remodeling in neurons through the medium of podosomes.
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Affiliation(s)
- Tazeen Qureshi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
| | - Smita Eknath Desale
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
| | - Hariharakrishnan Chidambaram
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India.
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4
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Karanth D, Song K, Martin ML, Meyer DR, Dolce C, Huang Y, Holliday LS. Towards resorbable 3D-printed scaffolds for craniofacial bone regeneration. Orthod Craniofac Res 2023; 26 Suppl 1:188-195. [PMID: 36866957 DOI: 10.1111/ocr.12645] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/19/2023] [Accepted: 02/24/2023] [Indexed: 03/04/2023]
Abstract
This review will briefly examine the development of 3D-printed scaffolds for craniofacial bone regeneration. We will, in particular, highlight our work using Poly(L-lactic acid) (PLLA) and collagen-based bio-inks. This paper is a narrative review of the materials used for scaffold fabrication by 3D printing. We have also reviewed two types of scaffolds that we designed and fabricated. Poly(L-lactic acid) (PLLA) scaffolds were printed using fused deposition modelling technology. Collagen-based scaffolds were printed using a bioprinting technique. These scaffolds were tested for their physical properties and biocompatibility. Work in the emerging field of 3D-printed scaffolds for bone repair is briefly reviewed. Our work provides an example of PLLA scaffolds that were successfully 3D-printed with optimal porosity, pore size and fibre thickness. The compressive modulus was similar to, or better than, the trabecular bone of the mandible. PLLA scaffolds generated an electric potential upon cyclic/repeated loading. The crystallinity was reduced during the 3D printing. The hydrolytic degradation was relatively slow. Osteoblast-like cells did not attach to uncoated scaffolds but attached well and proliferated after coating the scaffold with fibrinogen. Collagen-based bio-ink scaffolds were also printed successfully. Osteoclast-like cells adhered, differentiated, and survived well on the scaffold. Efforts are underway to identify means to improve the structural stability of the collagen-based scaffolds, perhaps through mineralization by the polymer-induced liquid precursor process. 3D-printing technology is promising for constructing next-generation bone regeneration scaffolds. We describe our efforts to test PLLA and collagen scaffolds produced by 3D printing. The 3D-printed PLLA scaffolds showed promising properties akin to natural bone. Collagen scaffolds need further work to improve structural integrity. Ideally, such biological scaffolds will be mineralized to produce true bone biomimetics. These scaffolds warrant further investigation for bone regeneration.
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Affiliation(s)
- Divakar Karanth
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Kaidong Song
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA
| | - Macey L Martin
- University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Delaney R Meyer
- Department of Materials Science & Engineering, University of Florida, Gainesville, Florida, USA
| | - Calogero Dolce
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Yong Huang
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - L Shannon Holliday
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida, USA
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5
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Shi S, Gu H, Xu J, Sun W, Liu C, Zhu T, Wang J, Gao F, Zhang J, Ou Q, Jin C, Xu J, Chen H, Li J, Xu G, Tian H, Lu L. Glia maturation factor beta deficiency protects against diabetic osteoporosis by suppressing osteoclast hyperactivity. Exp Mol Med 2023:10.1038/s12276-023-00980-8. [PMID: 37121966 DOI: 10.1038/s12276-023-00980-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 01/05/2023] [Accepted: 01/27/2023] [Indexed: 05/02/2023] Open
Abstract
Excessive osteoclast activation, which depends on dramatic changes in actin dynamics, causes osteoporosis (OP). The molecular mechanism of osteoclast activation in OP related to type 1 diabetes (T1D) remains unclear. Glia maturation factor beta (GMFB) is considered a growth and differentiation factor for both glia and neurons. Here, we demonstrated that Gmfb deficiency effectively ameliorated the phenotype of T1D-OP in rats by inhibiting osteoclast hyperactivity. In vitro assays showed that GMFB participated in osteoclast activation rather than proliferation. Gmfb deficiency did not affect osteoclast sealing zone (SZ) formation but effectively decreased the SZ area by decreasing actin depolymerization. When GMFB was overexpressed in Gmfb-deficient osteoclasts, the size of the SZ area was enlarged in a dose-dependent manner. Moreover, decreased actin depolymerization led to a decrease in nuclear G-actin, which activated MKL1/SRF-dependent gene transcription. We found that pro-osteoclastogenic factors (Mmp9 and Mmp14) were downregulated, while anti-osteoclastogenic factors (Cftr and Fhl2) were upregulated in Gmfb KO osteoclasts. A GMFB inhibitor, DS-30, targeting the binding site of GMFB and Arp2/3, was obtained. Biocore analysis revealed a high affinity between DS-30 and GMFB in a dose-dependent manner. As expected, DS-30 strongly suppressed osteoclast hyperactivity in vivo and in vitro. In conclusion, our work identified a new therapeutic strategy for T1D-OP treatment. The discovery of GMFB inhibitors will contribute to translational research on T1D-OP.
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Affiliation(s)
- Si Shi
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Huijie Gu
- Department of Orthopedics, Minhang Hospital, Fudan University, 170 Xinsong Road, Shanghai, 201199, PR China
| | - Jinyuan Xu
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Wan Sun
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Caiyin Liu
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Tong Zhu
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Juan Wang
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Furong Gao
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Jieping Zhang
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Qingjian Ou
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Caixia Jin
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Jingying Xu
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Hao Chen
- Department of Ophthalmology of Ten People Hospital Affiliated with Tongji University, School of Medicine, Shanghai, 200072, PR China
| | - Jiao Li
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China
| | - Guotong Xu
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China.
- Department of Pharmacology, Tongji University School of Medicine, Shanghai, PR China.
| | - Haibin Tian
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China.
- Department of Biochemistry and Molecular Biology, School of Medicine, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China.
| | - Lixia Lu
- Department of Ophthalmology of the Shanghai Tongji Hospital Affiliated with Tongji University, School of Medicine, and Tongji Eye Institute, 389 Xinchun Road, Shanghai, 200065, PR China.
- Department of Biochemistry and Molecular Biology, School of Medicine, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China.
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6
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Chen ZH, Wu JJ, Guo DY, Li YY, Chen MN, Zhang ZY, Yuan ZD, Zhang KW, Chen WW, Tian F, Ye JX, Li X, Yuan FL. Physiological functions of podosomes: From structure and function to therapy implications in osteoclast biology of bone resorption. Ageing Res Rev 2023; 85:101842. [PMID: 36621647 DOI: 10.1016/j.arr.2023.101842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/09/2022] [Accepted: 01/03/2023] [Indexed: 01/07/2023]
Abstract
With increasing age, bone tissue undergoes significant alterations in composition, architecture, and metabolic functions, probably causing senile osteoporosis. Osteoporosis possess the vast majority of bone disease and associates with a reduction in bone mass and increased fracture risk. Bone loss is on account of the disorder in osteoblast-induced bone formation and osteoclast-induced bone resorption. As a unique bone resorptive cell type, mature bone-resorbing osteoclasts exhibit dynamic actin-based cytoskeletal structures called podosomes that participate in cell-matrix adhesions specialized in the degradation of mineralized bone matrix. Podosomes share many of the same molecular constitutions as focal adhesions, but they have a unique structural organization, with a central core abundant in F-actin and encircled by scaffolding proteins, kinases and integrins. Here, we conclude recent advancements in our knowledge of the architecture and the functions of podosomes. We also discuss the regulatory pathways in osteoclast podosomes, providing a reference for future research on the podosomes of osteoclasts and considering podosomes as a therapeutic target for inhibiting bone resorption.
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Affiliation(s)
- Zhong-Hua Chen
- Affiliated Hospital 3 of Nantong University, Nantong University, Jiangsu, China
| | - Jun-Jie Wu
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Dan-Yang Guo
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Yue-Yue Li
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Meng-Nan Chen
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Zhen-Yu Zhang
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Zheng-Dong Yuan
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Kai-Wen Zhang
- Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Wei-Wei Chen
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Fan Tian
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Jun-Xing Ye
- Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China
| | - Xia Li
- Affiliated Hospital 3 of Nantong University, Nantong University, Jiangsu, China; Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China.
| | - Feng-Lai Yuan
- Affiliated Hospital 3 of Nantong University, Nantong University, Jiangsu, China; Institute of Integrated Chinese and Western Medicine, Affiliated Hospital of Jiangnan University, Jiangsu, China.
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7
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Wang X, Shao L, Richardson KK, Ling W, Warren A, Krager K, Aykin-Burns N, Hromas R, Zhou D, Almeida M, Kim HN. Hematopoietic cytoplasmic adaptor protein Hem1 promotes osteoclast fusion and bone resorption in mice. J Biol Chem 2023; 299:102841. [PMID: 36574841 PMCID: PMC9867982 DOI: 10.1016/j.jbc.2022.102841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/25/2022] Open
Abstract
Hem1 (hematopoietic protein 1), a hematopoietic cell-specific member of the Hem family of cytoplasmic adaptor proteins, is essential for lymphopoiesis and innate immunity as well as for the transition of hematopoiesis from the fetal liver to the bone marrow. However, the role of Hem1 in bone cell differentiation and bone remodeling is unknown. Here, we show that deletion of Hem1 resulted in a markedly increase in bone mass because of defective bone resorption in mice of both sexes. Hem1-deficient osteoclast progenitors were able to differentiate into osteoclasts, but the osteoclasts exhibited impaired osteoclast fusion and decreased bone-resorption activity, potentially because of decreased mitogen-activated protein kinase and tyrosine kinase c-Abl activity. Transplantation of bone marrow hematopoietic stem and progenitor cells from wildtype into Hem1 knockout mice increased bone resorption and normalized bone mass. These findings indicate that Hem1 plays a pivotal role in the maintenance of normal bone mass.
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Affiliation(s)
- Xiaoyan Wang
- Department of Pharmaceutical Sciences and Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Lijian Shao
- Department of Pharmaceutical Sciences and Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kimberly K Richardson
- Division of Endocrinology, Department of Internal Medicine, Center for Musculoskeletal Disease Research and Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Wen Ling
- Division of Endocrinology, Department of Internal Medicine, Center for Musculoskeletal Disease Research and Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Aaron Warren
- Division of Endocrinology, Department of Internal Medicine, Center for Musculoskeletal Disease Research and Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA
| | - Kimberly Krager
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Nukhet Aykin-Burns
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Robert Hromas
- Department of Medicine, The Long School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Daohong Zhou
- Department of Pharmaceutical Sciences and Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Department of Pharmacodynamics, University of Florida, Gainesville, Florida, USA
| | - Maria Almeida
- Division of Endocrinology, Department of Internal Medicine, Center for Musculoskeletal Disease Research and Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA; Department of Orthopedic Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
| | - Ha-Neui Kim
- Division of Endocrinology, Department of Internal Medicine, Center for Musculoskeletal Disease Research and Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA.
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8
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Portes M, Mangeat T, Escallier N, Dufrancais O, Raynaud-Messina B, Thibault C, Maridonneau-Parini I, Vérollet C, Poincloux R. Nanoscale architecture and coordination of actin cores within the sealing zone of human osteoclasts. eLife 2022; 11:75610. [PMID: 35727134 PMCID: PMC9255968 DOI: 10.7554/elife.75610] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Osteoclasts are unique in their capacity to degrade bone tissue. To achieve this process, osteoclasts form a specific structure called the sealing zone, which creates a close contact with bone and confines the release of protons and hydrolases for bone degradation. The sealing zone is composed of actin structures called podosomes nested in a dense actin network. The organization of these actin structures inside the sealing zone at the nano scale is still unknown. Here, we combine cutting-edge microscopy methods to reveal the nanoscale architecture and dynamics of the sealing zone formed by human osteoclasts on bone surface. Random illumination microscopy allowed the identification and live imaging of densely packed actin cores within the sealing zone. A cross-correlation analysis of the fluctuations of actin content at these cores indicates that they are locally synchronized. Further examination shows that the sealing zone is composed of groups of synchronized cores linked by a-actinin1 positive filaments, and encircled by adhesion complexes. Thus, we propose that the confinement of bone degradation mediators is achieved through the coordination of islets of actin cores and not by the global coordination of all podosomal subunits forming the sealing zone.
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Affiliation(s)
- Marion Portes
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Thomas Mangeat
- Centre de Biologie Intégrative, Université de Toulouse, CNRS, Toulouse, France
| | - Natacha Escallier
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Ophélie Dufrancais
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Brigitte Raynaud-Messina
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Christophe Thibault
- Laboratoire d'analyse et d'architectures des systèmes (LAAS), Université de Toulouse, CNRS, Toulouse, France
| | - Isabelle Maridonneau-Parini
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Christel Vérollet
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Renaud Poincloux
- Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
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9
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Identifying Novel Osteoarthritis-Associated Genes in Human Cartilage Using a Systematic Meta-Analysis and a Multi-Source Integrated Network. Int J Mol Sci 2022; 23:ijms23084395. [PMID: 35457215 PMCID: PMC9030814 DOI: 10.3390/ijms23084395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/12/2022] [Accepted: 04/14/2022] [Indexed: 11/16/2022] Open
Abstract
Osteoarthritis, the most common joint disorder, is characterised by deterioration of the articular cartilage. Many studies have identified potential therapeutic targets, yet no effective treatment has been determined. The aim of this study was to identify and rank osteoarthritis-associated genes and micro-RNAs to prioritise those most integral to the disease. A systematic meta-analysis of differentially expressed mRNA and micro-RNAs in human osteoarthritic cartilage was conducted. Ingenuity pathway analysis identified cellular senescence as an enriched pathway, confirmed by a significant overlap (p < 0.01) with cellular senescence drivers (CellAge Database). A co-expression network was built using genes from the meta-analysis as seed nodes and combined with micro-RNA targets and SNP datasets to construct a multi-source information network. This accumulated and connected 1689 genes which were ranked based on node and edge aggregated scores. These bioinformatic analyses were confirmed at the protein level by mass spectrometry of the different zones of human osteoarthritic cartilage (superficial, middle, and deep) compared to normal controls. This analysis, and subsequent experimental confirmation, revealed five novel osteoarthritis-associated proteins (PPIB, ASS1, LHDB, TPI1, and ARPC4-TTLL3). Focusing future studies on these novel targets may lead to new therapies for osteoarthritis.
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10
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Feng Z, Xu L, Xie Z. Receptors for Respiratory Syncytial Virus Infection and Host Factors Regulating the Life Cycle of Respiratory Syncytial Virus. Front Cell Infect Microbiol 2022; 12:858629. [PMID: 35281439 PMCID: PMC8913501 DOI: 10.3389/fcimb.2022.858629] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 01/27/2022] [Indexed: 12/02/2022] Open
Abstract
Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections and responsible for a large proportion of mortality in children and the elderly. There are no licensed vaccines available to date. Prophylaxis and therapeutic RSV-specific antibodies are limited to populations at high risk owing to high cost and uncertain clinical value. Receptors and host factors are two determinants important for virus entry and establishment of infection in vivo. The identification and understanding of viral receptors and host factors can help us to gain insight into the pathogenesis of RSV infection. Herein, we reviewed receptors and host factors that have been reported thus far. RSV could bind to CX3C chemokine receptor 1 and heparan sulfate proteoglycans via the G protein, and to nucleolin, insulin-like growth factor-1 receptor, epidermal growth factor, and intercellular adhesion molecule-1 via the F protein. Seven host restriction factors and 13 host factors essential for RSV infection were reviewed. We characterized the functions and their roles in the life cycle of RSV, trying to provide an update on the information of RSV-related receptors and host factors.
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Affiliation(s)
- Ziheng Feng
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
- Research Unit of Critical Infection in Children, Chinese Academy of Medical Sciences, Beijing, China
| | - Lili Xu
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
- Research Unit of Critical Infection in Children, Chinese Academy of Medical Sciences, Beijing, China
- *Correspondence: Lili Xu,
| | - Zhengde Xie
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China
- Research Unit of Critical Infection in Children, Chinese Academy of Medical Sciences, Beijing, China
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11
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Chellaiah MA. L-Plastin Phosphorylation: Possible Regulation by a TNFR1 Signaling Cascade in Osteoclasts. Cells 2021; 10:2432. [PMID: 34572081 PMCID: PMC8464874 DOI: 10.3390/cells10092432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/25/2021] [Accepted: 09/09/2021] [Indexed: 12/30/2022] Open
Abstract
Tumor necrosis factor-alpha (TNF-α) signaling regulates phosphorylation of L-plastin, which is involved in forming the nascent sealing zone, a precursor zone for the matured sealing ring. This study aimed to illustrate the molecular mechanisms of L-plastin phosphorylation and the subsequent formation of the nascent sealing zone in osteoclasts treated with TNF-α. Here, we report that anti-TNF-receptor 1, inhibitors of signaling proteins (Src, PI3-K, Rho, and Rho-kinase), and siRNA of TRAF-6 attenuated the phosphorylation of LPL and filamentous actin content significantly in the presence of TNF-α. An inhibitor of integrin αvβ3, PKC, or PKA did not inhibit TNF-α-induced L-plastin phosphorylation. Inhibitors of Src and PI3-K and not Rho or Rho-kinase reduced tyrosine phosphorylation of TRAF-6, suggesting that Src and PI3-K regulate TRAF-6 phosphorylation, and Rho and Rho-kinase are downstream of TRAF-6 regulation. Osteoclasts expressing constitutively active or kinase-defective Src proteins were used to determine the role of Src on L-plastin phosphorylation; similarly, the effect of Rho was confirmed by transducing TAT-fused constitutively active (V14) or dominant-negative (N19) Rho proteins into osteoclasts. Pull-down analysis with glutathione S-transferase-fused SH2 and SH3 domains of Src and PI3-K demonstrated coprecipitation of L-plastin and TRAF-6 with the SH3 and SH2 domains of the PI3-K and Src proteins. However, the actual order of the interaction of proteins requires further elucidation; a comprehensive screening should corroborate the initial findings of protein interactions via the SH2/SH3 domains. Ultimately, inhibition of the interaction of proteins with SH2/SH3 could reduce L-plastin phosphorylation and affect NSZ formation and bone resorption in conditions that display osteoclast activation and bone loss.
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Affiliation(s)
- Meenakshi A Chellaiah
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA
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12
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Murray JB, Mikhael C, Han G, de Faria LP, Rody WJ, Holliday LS. Activation of (pro)renin by (pro)renin receptor in extracellular vesicles from osteoclasts. Sci Rep 2021; 11:9214. [PMID: 33911158 PMCID: PMC8080643 DOI: 10.1038/s41598-021-88665-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
The (pro)renin receptor (PRR) is a multifunctional integral membrane protein that serves as a component of the vacuolar H+-ATPase (V-ATPase) and also activates (pro)renin. We recently showed that full-length PRR, found as part of a V-ATPase sub-complex, is abundant in extracellular vesicles shed by osteoclasts. Here, we tested whether these extracellular vesicles stimulate (pro)renin. Extracellular vesicles isolated from the conditioned media of RAW 264.7 osteoclast-like cells or primary osteoclasts were characterized and counted by nanoparticle tracking. Immunoblotting confirmed that full-length PRR was present. Extracellular vesicles from osteoclasts dose-dependently stimulated (pro)renin activity, while extracellular vesicles from 4T1 cancer cells, in which we did not detect PRR, did not activate (pro)renin. To confirm that the ability of extracellular vesicles from osteoclasts to stimulate (pro)renin activity was due to the PRR, the "handle region peptide" from the PRR, a competitive inhibitor of PRR activity, was tested. It dose-dependently blocked the ability of extracellular vesicles to stimulate the enzymatic activity of (pro)renin. In summary, the PRR, an abundant component of extracellular vesicles shed by osteoclasts, stimulates (pro)renin activity. This represents a novel mechanism by which extracellular vesicles can function in intercellular regulation, with direct implications for bone biology.
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Affiliation(s)
- Jonathan B Murray
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, 32610, USA
| | - Christy Mikhael
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, 32610, USA
| | - Guanghong Han
- Department of Oral Geriatrics, Hospital of Stomatology, Jilin University, Changchun, 130021, People's Republic of China
| | - Lorraine Perciliano de Faria
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, 01000, Brazil
| | - Wellington J Rody
- Department of Orthodontics and Pediatric Dentistry, Stony Brook University School of Dental Medicine, Stony Brook, NY, 11794, USA
| | - L Shannon Holliday
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, 32610, USA.
- Department of Anatomy & Cell Biology, University of Florida College of Medicine, Gainesville, FL, 23610, USA.
- Department of Orthodontics, University of Florida College of Dentistry, 1600 SW Archer Road, CB 1000444, Gainesville, FL, 23610, USA.
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13
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Place DE, Malireddi RKS, Kim J, Vogel P, Yamamoto M, Kanneganti TD. Osteoclast fusion and bone loss are restricted by interferon inducible guanylate binding proteins. Nat Commun 2021; 12:496. [PMID: 33479228 PMCID: PMC7820603 DOI: 10.1038/s41467-020-20807-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
Chronic inflammation during many diseases is associated with bone loss. While interferons (IFNs) are often inhibitory to osteoclast formation, the complex role that IFN and interferon-stimulated genes (ISGs) play in osteoimmunology during inflammatory diseases is still poorly understood. We show that mice deficient in IFN signaling components including IFN alpha and beta receptor 1 (IFNAR1), interferon regulatory factor 1 (IRF1), IRF9, and STAT1 each have reduced bone density and increased osteoclastogenesis compared to wild type mice. The IFN-inducible guanylate-binding proteins (GBPs) on mouse chromosome 3 (GBP1, GBP2, GBP3, GBP5, GBP7) are required to negatively regulate age-associated bone loss and osteoclastogenesis. Mechanistically, GBP2 and GBP5 both negatively regulate in vitro osteoclast differentiation, and loss of GBP5, but not GBP2, results in greater age-associated bone loss in mice. Moreover, mice deficient in GBP5 or chromosome 3 GBPs have greater LPS-mediated inflammatory bone loss compared to wild type mice. Overall, we find that GBP5 contributes to restricting age-associated and inflammation-induced bone loss by negatively regulating osteoclastogenesis.
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Affiliation(s)
- David E Place
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - R K Subbarao Malireddi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Jieun Kim
- Center for In Vivo Imaging and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Peter Vogel
- Veterinary Pathology Core, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
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14
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DNA mechanotechnology reveals that integrin receptors apply pN forces in podosomes on fluid substrates. Nat Commun 2019; 10:4507. [PMID: 31628308 PMCID: PMC6800454 DOI: 10.1038/s41467-019-12304-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 08/22/2019] [Indexed: 12/27/2022] Open
Abstract
Podosomes are ubiquitous cellular structures important to diverse processes including cell invasion, migration, bone resorption, and immune surveillance. Structurally, podosomes consist of a protrusive actin core surrounded by adhesion proteins. Although podosome protrusion forces have been quantified, the magnitude, spatial distribution, and orientation of the opposing tensile forces remain poorly characterized. Here we use DNA nanotechnology to create probes that measure and manipulate podosome tensile forces with molecular piconewton (pN) resolution. Specifically, Molecular Tension-Fluorescence Lifetime Imaging Microscopy (MT-FLIM) produces maps of the cellular adhesive landscape, revealing ring-like tensile forces surrounding podosome cores. Photocleavable adhesion ligands, breakable DNA force probes, and pharmacological inhibition demonstrate local mechanical coupling between integrin tension and actin protrusion. Thus, podosomes use pN integrin forces to sense and respond to substrate mechanics. This work deepens our understanding of podosome mechanotransduction and contributes tools that are widely applicable for studying receptor mechanics at dynamic interfaces.
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15
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Lin X, Xiao Y, Chen Z, Ma J, Qiu W, Zhang K, Xu F, Dang K, Qian A. Microtubule actin crosslinking factor 1 (MACF1) knockdown inhibits RANKL-induced osteoclastogenesis via Akt/GSK3β/NFATc1 signalling pathway. Mol Cell Endocrinol 2019; 494:110494. [PMID: 31260729 DOI: 10.1016/j.mce.2019.110494] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 01/23/2023]
Abstract
Osteoclasts are responsible for bone resorption and play essential roles in causing bone diseases such as osteoporosis. Microtubule actin crosslinking factor 1 (MACF1) is a large spectraplakin protein that has been implicated in regulating cytoskeletal distribution, cell migration, cell survival and cell differentiation. However, whether MACF1 regulates the differentiation of osteoclasts has not been elucidated. In this study, we found that the expression of MACF1 was increased in primary bone marrow-derived monocytes (BMMs) of osteoporotic mice and was downregulated during receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis of pre-osteoclast cell lines RAW264.7 cells. RAW264.7 cells were transfected with shMACF1 using a lentiviral vector to study the role of MACF1 in osteoclastogenic differentiation. Knockdown of MACF1 in RAW264.7 cells inhibited the formation of multinucleated osteoclasts and decreased the expression of osteoclast-marker genes (Ctsk, Acp5, Mmp9 and Oscar) during RANKL-induced osteoclastogenesis. Additionally, knockdown of MACF1 disrupted actin ring formation in osteoclasts and further blocked the bone resorption activity of osteoclasts by reducing the area and depth of pits. Knockdown of MACF1 had no effect on the survival of pre-osteoclasts and mature osteoclasts. We further established that knockdown of MACF1 attenuated the phosphorylation of Akt and GSK3β and inhibited the expression of its downstream target NFATc1. Akt activator rescued the inhibition of osteoclast differentiation by MACF1 knockdown. These data demonstrate that MACF1 positively regulates osteoclast differentiation via the Akt/GSK3β/NFATc1 signalling pathway, suggesting that targeting MACF1 may be a novel therapeutic approach against osteoporosis.
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Affiliation(s)
- Xiao Lin
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Yunyun Xiao
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Zhihao Chen
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Jianhua Ma
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Wuxia Qiu
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Kewen Zhang
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Fang Xu
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Kai Dang
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Airong Qian
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China.
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16
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Akisaka T, Yoshida A. Scattered podosomes and podosomes associated with the sealing zone architecture in cultured osteoclasts revealed by cell shearing, quick freezing, and platinum-replica electron microscopy. Cytoskeleton (Hoboken) 2019; 76:303-321. [PMID: 31162808 DOI: 10.1002/cm.21543] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/24/2019] [Accepted: 05/30/2019] [Indexed: 01/06/2023]
Abstract
Osteoclasts (OCs) can adhere to a variety of substrate surfaces by highly dynamic actin-based cytoskeletal structures termed podosomes. This tight attachment is established by a sealing zone (SZ), which is made of interconnected individual podosomes. Compared with scattered podosomes in various cell types, the architecture of the SZ is still unclear. Especially, ultrastructural studies on the details of the cytoskeletal structure of an OC have been challenging, because the high density of filaments in their podosomes obscure visualization of individual filaments. Therefore, to study this organization in more exact detail, we employed shearing open combined with replica electron microscopy. The present study provides several new details of the podosome and SZ structure, which were previously unrecognized: (a) the SZ consists of recognizable podosomes with a dense actin network of interpodosomal regions characterized by multiple layers of crossing, branching and anastomosing actin filament networks; (b) the Arp2/3 complex is distributed throughout the actin network of podosomes and SZ, indicating that actin polymerization is concentrated at these regions; (c) a close spatial relationship between the podosome and the dorsal membrane; and (d) a network of membranous organelles in close proximity to the podosomes in the SZ. Taken together, the present study reveals that a more complicated interpodosomal actin network among neighboring individual podosomes, which is more complicated than previously thought, appears to form the SZ. Indeed, individual podosomes are not an isolated structural unit from other organelles; and, in turn, their dynamism might affect the surrounding interpodosomal cytoskeletons, membranous organelles, and plasma membrane.
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Affiliation(s)
- Toshitaka Akisaka
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Atsushi Yoshida
- Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
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17
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Engineering of L-Plastin Peptide-Loaded Biodegradable Nanoparticles for Sustained Delivery and Suppression of Osteoclast Function In Vitro. Int J Cell Biol 2019; 2019:6943986. [PMID: 31191656 PMCID: PMC6525930 DOI: 10.1155/2019/6943986] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 04/09/2019] [Accepted: 04/15/2019] [Indexed: 12/15/2022] Open
Abstract
We have recently demonstrated that a small molecular weight amino-terminal peptide of L-plastin (10 amino acids; “MARGSVSDEE”) suppressed the phosphorylation of endogenous L-plastin. Therefore, the formation of nascent sealing zones (NSZs) and bone resorption are reduced. The aim of this study was to develop a biodegradable and biocompatible PLGA nanocarrier that could be loaded with the L-plastin peptide of interest and determine the efficacy in vitro in osteoclast cultures. L-plastin MARGSVSDEE (P1) and scrambled control (P3) peptide-loaded PLGA-PEG nanoparticles (NP1 and NP3, respectively) were synthesized by double emulsion technique. The biological effect of nanoparticles on osteoclasts was evaluated by immunoprecipitation, immunoblotting, rhodamine-phalloidin staining of actin filaments, and pit forming assays. Physical characterization of well-dispersed NP1 and NP3 demonstrated ~130-150 nm size, < 0.07 polydispersity index, ~-3 mV ζ-potential, and a sustained release of the peptide for three weeks. Biological characterization in osteoclast cultures demonstrated the following: NP1 significantly reduced (a) endogenous L-plastin phosphorylation; (b) formation of NSZs and sealing rings; (c) resorption. However, the assembly of podosomes which are critical for cell adhesion was not affected. L-plastin peptide-loaded PLGA-PEG nanocarriers have promising potential for the treatment of diseases associated with bone loss. Future studies will use this sustained release of peptide strategy to systematically suppress osteoclast bone resorption activity in vivo in mouse models demonstrating bone loss.
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18
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Han G, Zuo J, Holliday LS. Specialized Roles for Actin in Osteoclasts: Unanswered Questions and Therapeutic Opportunities. Biomolecules 2019; 9:biom9010017. [PMID: 30634501 PMCID: PMC6359508 DOI: 10.3390/biom9010017] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 12/11/2022] Open
Abstract
Osteoclasts are cells of the hematopoietic lineage that are specialized to resorb bone. In osteoclasts, the actin cytoskeleton engages in at least two unusual activities that are required for resorption. First, microfilaments form a dynamic and structurally elaborate actin ring. Second, microfilaments bind vacuolar H⁺-ATPase (V-ATPase) and are involved in forming the V-ATPase-rich ruffled plasma membrane. The current review examines these two specialized functions with emphasis on the identification of new therapeutic opportunities. The actin ring is composed of substructures called podosomes that are interwoven to form a cohesive superstructure. Studies examining the regulation of the formation of actin rings and its constituent proteins are reviewed. Areas where there are gaps in the knowledge are highlighted. Microfilaments directly interact with the V-ATPase through an actin binding site in the B2-subunit of V-ATPase. This binding interaction is required for ruffled membrane formation. Recent studies show that an inhibitor of the interaction blocks bone resorption in pre-clinical animal models, including a model of post-menopausal osteoporosis. Because the unusual actin-based resorption complex is unique to osteoclasts and essential for bone resorption, it is likely that deeper understanding of its underlying mechanisms will lead to new approaches to treat bone disease.
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Affiliation(s)
- Guanghong Han
- Department of Stomatology, College and Hospital of Stomatology, Jilin University, Changchun 130021, China.
| | - Jian Zuo
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
| | - Lexie Shannon Holliday
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
- Department of Anatomy & Cell Biology, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
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19
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Uehara S, Udagawa N, Kobayashi Y. Non-canonical Wnt signals regulate cytoskeletal remodeling in osteoclasts. Cell Mol Life Sci 2018; 75:3683-3692. [PMID: 30051162 PMCID: PMC6154041 DOI: 10.1007/s00018-018-2881-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 12/11/2022]
Abstract
Osteoclasts are multinucleated cells responsible for bone resorption. Osteoclasts adhere to the bone surface through integrins and polarize to form actin rings, which are formed by the assembly of podosomes. The area contained within actin rings (also called sealing zones) has an acidic pH, which causes dissolution of bone minerals including hydroxyapatite and the degradation of matrix proteins including type I collagen by the protease cathepsin K. Osteoclasts resorb bone matrices while moving on bone surfaces. Osteoclasts change their cell shapes and exhibit three modes for bone resorption: motile resorbing mode for digging trenches, static resorbing mode for digging pits, and motile non-resorbing mode. Therefore, the actin cytoskeleton is actively remodeled in osteoclasts. Recent studies have revealed that many molecules, such as Rac, Cdc42, Rho, and small GTPase regulators and effectors, are involved in actin cytoskeletal remodeling during the formation of actin rings and resorption cavities on bone slices. In this review, we introduce how these molecules and non-canonical Wnt signaling regulate the bone-resorbing activity of osteoclasts.
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Affiliation(s)
- Shunsuke Uehara
- Department of Biochemistry, Matsumoto Dental University, Nagano, 399-0781, Japan
| | - Nobuyuki Udagawa
- Department of Biochemistry, Matsumoto Dental University, Nagano, 399-0781, Japan
| | - Yasuhiro Kobayashi
- Institute for Oral Science, Matsumoto Dental University, 1780 Gobara, Hiro-oka, Shiojiri, Nagano, 399-0781, Japan.
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20
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Wijekoon HMS, Bwalya EC, Fang J, Kim S, Hosoya K, Okumura M. Inhibitory effects of sodium pentosan polysulfate on formation and function of osteoclasts derived from canine bone marrow. BMC Vet Res 2018; 14:152. [PMID: 29720166 PMCID: PMC5930774 DOI: 10.1186/s12917-018-1466-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 04/20/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Sodium pentosan polysulfate (NaPPS) was testified as a chondroprotective drug in with a detailed rationale of the disease-modifying activity. This study was undertaken to determine whether anti-osteoarthritis drug, NaPPS inhibited osteoclasts (OC) differentiation and function. Canine bone marrow mononuclear cells (n = 6) were differentiated to OC by maintaining with receptor activator of nuclear factor kappa B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) for up to 7 days with the treatment of NaPPS at concentration of 0, 0.2, 1 and 5 μg/mL. Differentiation and function of OC were accessed using tartrate-resistant acid phosphate (TRAP) staining and bone resorption assay, while monitoring actin ring formation. Invasion and colocalization patterns of fluorescence-labeled NaPPS with transcribed gene in OC were monitored. Gene expression of OC for cathepsin K (CTK), matrix metallopeptidase-9 (MMP-9), nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), c-Fos, activator protein-1(AP-1) and carbonic anhydrase II was examined using real-time PCR. RESULTS Significant inhibition of OC differentiation was evident at NaPPS concentration of 1 and 5 μg/mL (p < 0.05). In the presence of 0.2 to 5 μg/mL NaPPS, bone resorption was attenuated (p < 0.05), while 1 and 5 μg/mL NaPPS achieved significant reduction of actin ring formation. Intriguingly, fluorescence-labeled NaPPS invaded in to cytoplasm and nucleus while colocalizing with actively transcribed gene. Gene expression of CTK, MMP-9 and NFATc1 were significantly inhibited at 1 and 5 μg/mL (p < 0.05) of NaPPS whereas inhibition of c-Fos and AP-1 was identified only at concentration of 5 μg/mL (p < 0.05). CONCLUSIONS Taken together, all the results suggest that NaPPS is a novel inhibitor of RANKL and M-CSF-induced CTK, MMP-9, NFATc1, c-Fos, AP-1 upregulation, OC differentiation and bone resorption which might be a beneficial for treatment of inflammatory joint diseases and other bone diseases associated with excessive bone resorption.
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Affiliation(s)
- H. M. Suranji Wijekoon
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Eugene C. Bwalya
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Jing Fang
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Sangho Kim
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Kenji Hosoya
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
| | - Masahiro Okumura
- Department of Veterinary Clinical Sciences, Laboratory of Veterinary Surgery, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818 Japan
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21
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Singhto N, Kanlaya R, Nilnumkhum A, Thongboonkerd V. Roles of Macrophage Exosomes in Immune Response to Calcium Oxalate Monohydrate Crystals. Front Immunol 2018. [PMID: 29535716 PMCID: PMC5835051 DOI: 10.3389/fimmu.2018.00316] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In kidney stone disease, macrophages secrete various mediators via classical secretory pathway and cause renal interstitial inflammation. However, whether their extracellular vesicles, particularly exosomes, are involved in kidney stone pathogenesis remained unknown. This study investigated alterations in exosomal proteome of U937-derived macrophages (by phorbol-12-myristate-13-acetate activation) after exposure to calcium oxalate monohydrate (COM) crystals for 16-h using 2-DE-based proteomics approach. Six significantly altered proteins in COM-treated exosomes were successfully identified by nanoscale liquid chromatography–electrospray ionization–electron transfer dissociation tandem mass spectrometry as proteins involved mainly in immune processes, including T-cell activation and homeostasis, Fcγ receptor-mediated phagocytosis, interferon-γ (IFN-γ) regulation, and cell migration/movement. The decreased heat shock protein 90-beta (HSP90β) and increased vimentin were confirmed by Western blotting. ELISA showed that the COM-treated macrophages produced greater level of interleukin-1β (IL-1β), one of the markers for inflammasome activation. Functional studies demonstrated that COM-treated exosomes enhanced monocyte and T-cell migration, monocyte activation and macrophage phagocytic activity, but on the other hand, reduced T-cell activation. In addition, COM-treated exosomes enhanced production of proinflammatory cytokine IL-8 by monocytes that could be restored to its basal level by small-interfering RNA targeting on vimentin (si-Vimentin). Moreover, si-Vimentin could also abolish effects of COM-treated exosomes on monocyte and T-cell migration as well as macrophage phagocytic activity. These findings provided some implications to the immune response during kidney stone pathogenesis via exosomal pathway of macrophages after exposure to COM crystals.
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Affiliation(s)
- Nilubon Singhto
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Immunology Graduate Program, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Rattiyaporn Kanlaya
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Angkhana Nilnumkhum
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Visith Thongboonkerd
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
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22
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The Actin-Binding Protein PPP1r18 Regulates Maturation, Actin Organization, and Bone Resorption Activity of Osteoclasts. Mol Cell Biol 2018; 38:MCB.00425-17. [PMID: 29158294 DOI: 10.1128/mcb.00425-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/11/2017] [Indexed: 01/21/2023] Open
Abstract
Osteoclasts resorb bone by attaching on the bone matrix and forming a sealing zone. In Src-deficient mice, osteoclasts cannot form the actin ring, a characteristic actin structure that seals the resorbed area, and resorb hardly any bone as a result. However, the molecular mechanism underlying the role of Src in the regulation and organization of the actin ring is still unclear. We identified an actin-regulatory protein, protein phosphatase 1 regulatory subunit 18 (PPP1r18), as an Src-binding protein in an Src-, Yes-, and Fyn-deficient fibroblast (SYF) cell line overexpressing a constitutively active form of Src. PPP1r18 was localized in the nucleus and actin ring. PPP1r18 overexpression in osteoclasts inhibited terminal differentiation, actin ring formation, and bone-resorbing activity. A mutation of the protein phosphatase 1 (PP1)-binding domain of PPP1r18 rescued these phenotypes. In contrast, PPP1r18 knockdown promoted terminal differentiation and actin ring formation. In summary, we showed that PPP1r18 likely plays a role in podosome organization and bone resorption.
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23
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Takito J, Otsuka H, Inoue S, Kawashima T, Nakamura M. Symmetrical retrograde actin flow in the actin fusion structure is involved in osteoclast fusion. Biol Open 2017; 6:1104-1114. [PMID: 28711870 PMCID: PMC5550915 DOI: 10.1242/bio.025460] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The aim of this study was to elucidate the role of the zipper-like structure (ZLS), a podosome-related structure that transiently appears at the cell contact zone, in osteoclast fusion. Live-cell imaging of osteoclasts derived from RAW264.7 cells transfected with EGFP-actin revealed consistent symmetrical retrograde actin flow in the ZLS, but not in the podosome cluster, the podosome ring or the podosome belt. Confocal imaging showed that the distributions of F-actin, vinculin, paxillin and zyxin in the ZLS were different from those in the podosome belt. Thick actin filament bundles running outside the ZLS appeared to recruit non-muscle myosin IIA. The F-actin-rich domain of the ZLS contained actin-related protein 2/3 complex (Arp2/3). Inhibition of Arp2/3 activity disorganized the ZLS, disrupted actin flow, deteriorated cell-cell adhesion and inhibited osteoclast hypermultinucleation. In contrast, ML-7, an inhibitor of myosin light chain kinase, had little effect on the structure of ZLS and promoted osteoclast hypermultinucleation. These results reveal a link between actin flow in the ZLS and osteoclast fusion. Osteoclast fusion was promoted by branched actin elongation and negatively regulated by actomyosin contraction. Summary: Multinucleated osteoclasts form a podosome-derived fusion structure during cell fusion. Juxtaposition of fusion partner cells is probably maintained via force generated by symmetrical retrograde actin flow in the fusion structure.
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Affiliation(s)
- Jiro Takito
- Department of Oral Anatomy and Developmental Biology, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan
| | - Hirotada Otsuka
- Department of Oral Anatomy and Developmental Biology, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan
| | - Satoshi Inoue
- Department of Oral Anatomy and Developmental Biology, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan
| | - Tsubasa Kawashima
- Department of Paediatric Dentistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan
| | - Masanori Nakamura
- Department of Oral Anatomy and Developmental Biology, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan
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24
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Kaczor-Urbanowicz KE, Deutsch O, Zaks B, Krief G, Chaushu S, Palmon A. Identification of salivary protein biomarkers for orthodontically induced inflammatory root resorption. Proteomics Clin Appl 2017; 11. [PMID: 28371361 DOI: 10.1002/prca.201600119] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 03/19/2017] [Accepted: 03/27/2017] [Indexed: 12/31/2022]
Abstract
PURPOSE Orthodontically induced inflammatory root resorption (OIIRR) is one of the most prevalent and unavoidable consequence of orthodontic tooth movement. The aim of this study was to discover potential diagnostic protein biomarkers for detection of OIIRR in whole saliva (WS). MATERIAL AND METHODS Unstimulated WS was collected from 72 subjects: 48 OIIRR patients and 24 untreated, generally healthy, age and gender matched controls. Radiographic assessment of periapical x-rays of four upper incisors taken before and 9 months after bonding was done. High-abundance proteins were depleted followed by two-dimensional-gel-electrophoresis and quantitative mass spectrometry (qMS). Finally, to initially validate qMS results, Western blotting was performed. RESULTS qMS revealed differentially expressed proteins in the moderate-to-severe OIIRR group, which have never been found in WS before. Additionally, in the moderate-to-severe young OIIRR group, the pathogenetic mechanisms related to actin cytoskeleton regulation and Fc gamma R- mediated phagocytosis were detected, while in adults- to focal adhesion. Preliminary validation by Western blotting of fetuin-A and p21-ARC indicated expression profile trends similar to those identified by qMS. CONCLUSION The significance of WS novel proteomic methodologies is clearly demonstrated for detecting new OIIRR biomarkers as well as for unveiling possible novel pathogenetic mechanisms in both young and adult patients.
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Affiliation(s)
- Karolina Elżbieta Kaczor-Urbanowicz
- Department of Orthodontics, The Hebrew University of Jerusalem, Hadassah School of Dental Medicine, Israel.,Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Israel
| | - Omer Deutsch
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Israel
| | - Batia Zaks
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Israel
| | - Guy Krief
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Israel
| | - Stella Chaushu
- Department of Orthodontics, The Hebrew University of Jerusalem, Hadassah School of Dental Medicine, Israel
| | - Aaron Palmon
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Israel
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25
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Ramos-Junior ES, Leite GA, Carmo-Silva CC, Taira TM, Neves KB, Colón DF, da Silva LA, Salvador SL, Tostes RC, Cunha FQ, Fukada SY. Adipokine Chemerin Bridges Metabolic Dyslipidemia and Alveolar Bone Loss in Mice. J Bone Miner Res 2017; 32:974-984. [PMID: 28029186 DOI: 10.1002/jbmr.3072] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/21/2016] [Accepted: 12/26/2016] [Indexed: 12/12/2022]
Abstract
Chemerin is an adipokine that regulates adipogenesis and metabolic functions of mature adipocytes mainly through the activation of chemokine-like receptor 1 (CMKLR1). Elevated levels of chemerin have been found in individuals with obesity, type 2 diabetes, and osteoporosis. This adipokine was identified as an inflammatory and metabolic syndrome marker. Considering that the association between metabolic syndrome and bone health remains unclear, the present study aimed to clarify the role of chemerin in the pathophysiology of bone loss induced by dyslipidemia, particularly modulating osteoclastogenesis. In vitro analyses showed a downregulation of CMKLR1 at the early stage of differentiation and a gradual increase at late stages. Strikingly, chemerin did not modify osteoclast differentiation markers or osteoclast formation; however, it increased the actin-ring formation and bone resorption activity in mature osteoclasts. The increased bone resorption activity induced by chemerin was effectively inhibited by CMKLR1 antagonist (CCX832). Chemerin boosting mature osteoclast activity involves ERK5 phosphorylation. Moreover, two models of dyslipidemia (high-fat diet [HFD]-treated C57/BL6 and db/db mice) exhibited significantly increased level of chemerin in the serum and gingival tissue. Morphometric analysis showed that HFD-treated and db/db mice exhibited increased alveolar bone loss compared to respective control mice, which was associated with an up-regulation of chemerin, CMKLR1 and cathepsin K mRNA expression in the gingival tissue. The treatment of db/db mice with CCX832 effectively inhibited bone loss. Antagonism of chemerin receptor also inhibited the expression of cathepsin K in the gingival tissue. Our results show that chemerin not only increases osteoclasts activity in vitro, but also that increased level of chemerin in dyslipidemic mice plays a critical role in bone homeostasis. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Erivan S Ramos-Junior
- School of Pharmaceutical Sciences of Ribeirao Preto, Department of Physics and Chemistry, University of Sao Paulo, Sao Paulo, Brazil
| | - Gisele A Leite
- School of Dentistry of Ribeirao Preto, Department of Pediatric Dentistry, University of Sao Paulo, Sao Paulo, Brazil
| | - Cecilia C Carmo-Silva
- School of Pharmaceutical Sciences of Ribeirao Preto, Department of Physics and Chemistry, University of Sao Paulo, Sao Paulo, Brazil
| | - Thaise M Taira
- School of Dentistry of Ribeirao Preto, Department of Pediatric Dentistry, University of Sao Paulo, Sao Paulo, Brazil
| | - Karla B Neves
- School of Medicine of Ribeirao Preto, Department of Pharmacology, University of Sao Paulo, Sao Paulo, Brazil
| | - David F Colón
- School of Medicine of Ribeirao Preto, Department of Pharmacology, University of Sao Paulo, Sao Paulo, Brazil
| | - Lea Ab da Silva
- School of Dentistry of Ribeirao Preto, Department of Pediatric Dentistry, University of Sao Paulo, Sao Paulo, Brazil
| | - Sergio L Salvador
- School of Pharmaceutical Sciences of Ribeirao Preto, Department of Clinical Analyses, University of Sao Paulo, Sao Paulo, Brazil
| | - Rita C Tostes
- School of Medicine of Ribeirao Preto, Department of Pharmacology, University of Sao Paulo, Sao Paulo, Brazil
| | - Fernando Q Cunha
- School of Medicine of Ribeirao Preto, Department of Pharmacology, University of Sao Paulo, Sao Paulo, Brazil
| | - Sandra Y Fukada
- School of Pharmaceutical Sciences of Ribeirao Preto, Department of Physics and Chemistry, University of Sao Paulo, Sao Paulo, Brazil
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26
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Significance of kinase activity in the dynamic invadosome. Eur J Cell Biol 2016; 95:483-492. [PMID: 27465307 DOI: 10.1016/j.ejcb.2016.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 07/08/2016] [Accepted: 07/13/2016] [Indexed: 12/19/2022] Open
Abstract
Invadosomes are actin rich protrusive structures that facilitate invasive migration in multiple cell types. Comprised of invadopodia and podosomes, these highly dynamic structures adhere to and degrade the extracellular matrix, and are also thought to play a role in mechanosensing. Many extracellular signals have been implicated in invadosome stimulation, activating complex signalling cascades to drive the formation, activity and turnover of invadosomes. While the structural components of invadosomes have been well studied, the regulation of invadosome dynamics is still poorly understood. Protein kinases are essential to this regulation, affecting all stages of invadosome dynamics and allowing tight spatiotemporal control of their activity. Invadosome organisation and function have been linked to pathophysiological states such as cancer invasion and metastasis; therapeutic targeting of invadosome regulatory components is thus warranted. In this review, we discuss the involvement of kinase signalling in every stage of the invadosome life cycle and evaluate its significance.
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27
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In vitro model of bone to facilitate measurement of adhesion forces and super-resolution imaging of osteoclasts. Sci Rep 2016; 6:22585. [PMID: 26935172 PMCID: PMC4776281 DOI: 10.1038/srep22585] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/18/2016] [Indexed: 11/08/2022] Open
Abstract
To elucidate processes in the osteoclastic bone resorption, visualise resorption and related actin reorganisation, a combination of imaging technologies and an applicable in vitro model is needed. Nanosized bone powder from matching species is deposited on any biocompatible surface in order to form a thin, translucent, smooth and elastic representation of injured bone. Osteoclasts cultured on the layer expressed matching morphology to ones cultured on sawed cortical bone slices. Resorption pits were easily identified by reflectance microscopy. The coating allowed actin structures on the bone interface to be visualised with super-resolution microscopy along with a detailed interlinked actin networks and actin branching in conjunction with V-ATPase, dynamin and Arp2/3 at actin patches. Furthermore, we measured the timescale of an adaptive osteoclast adhesion to bone by force spectroscopy experiments on live osteoclasts with bone-coated AFM cantilevers. Utilising the in vitro model and the advanced imaging technologies we localised immunofluorescence signals in respect to bone with high precision and detected resorption at its early stages. Put together, our data supports a cyclic model for resorption in human osteoclasts.
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28
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Huynh N, VonMoss L, Smith D, Rahman I, Felemban MF, Zuo J, Rody WJ, McHugh KP, Holliday LS. Characterization of Regulatory Extracellular Vesicles from Osteoclasts. J Dent Res 2016; 95:673-9. [PMID: 26908631 DOI: 10.1177/0022034516633189] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Extracellular vesicles (EVs), which include exosomes and ectosomes/microvesicles, have emerged as important intercellular regulators. EVs can interact with surface receptors of target cells and can transport luminal components, including messenger RNAs (mRNAs), microRNAs, and enzymes, to the cytosol of the target cell. Here, we show that hematopoietic cells grown in culture shed exosome-like EVs as they differentiate from preosteoclasts into osteoclasts. These EVs were between 25 and 120 nm (mean, 40 nm) in diameter determined by transmission electron microscopy. The exosome-associated markers CD63 and EpCAM were enriched in the isolated EVs while markers of Golgi and endoplasmic reticulum were not detected. Treatment of isolated hematopoietic cells with EVs did not affect their receptor activator of nuclear factor κB-ligand (RANKL)-stimulated differentiation into osteoclasts. However, EVs from osteoclast precursors promoted 1,25-dihydroxyvitamin D3-dependent osteoclast formation in whole mouse marrow cultures, and EVs from osteoclast-enriched cultures inhibited osteoclastogenesis in the same cultures. These data suggested that osteoclast-derived EVs are paracrine regulators of osteoclastogenesis. EVs from mature osteoclasts contained receptor activator of nuclear factor κB (RANK). Immunogold labeling showed RANK was enriched in 1 in every 32 EVs isolated from osteoclast-enriched cultures. Depletion of RANK-rich EVs relieved the ability of osteoclast-derived EVs to inhibit osteoclast formation in 1,25-dihydroxyvitamin D3-stimulated marrow cultures. In summary, we show for the first time that EVs released by osteoclasts are novel regulators of osteoclastogenesis. Our data suggest that RANK in EVs may be mechanistically linked to the inhibition of osteoclast formation. RANK present in EVs may function by competitively inhibiting the stimulation of RANK on osteoclast surfaces by RANKL similar to osteoprotegerin. RANK-rich EVs may also take advantage of the RANK/RANKL interaction to target RANK-rich EVs to RANKL-bearing cells for the delivery of other regulatory molecules.
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Affiliation(s)
- N Huynh
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - L VonMoss
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - D Smith
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - I Rahman
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - M F Felemban
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - J Zuo
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - W J Rody
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - K P McHugh
- Department of Periodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - L S Holliday
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL, USA
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29
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Caster DJ, Korte EA, Merchant ML, Klein JB, Wilkey DW, Rovin BH, Birmingham DJ, Harley JB, Cobb BL, Namjou B, McLeish KR, Powell DW. Autoantibodies targeting glomerular annexin A2 identify patients with proliferative lupus nephritis. Proteomics Clin Appl 2015; 9:1012-20. [PMID: 25824007 DOI: 10.1002/prca.201400175] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 02/10/2015] [Accepted: 03/26/2015] [Indexed: 11/09/2022]
Abstract
PURPOSE Patients with systemic lupus erythematosus (SLE) frequently develop lupus nephritis (LN), a complication frequently leading to end stage kidney disease. Immune complex deposition in the glomerulus is central to the development of LN. Using a targeted proteomic approach, we tested the hypothesis that autoantibodies targeting glomerular antigens contribute to the development of LN. EXPERIMENTAL DESIGN Human podocyte and glomerular proteins were separated by SDS-PAGE and immunoblotted with sera from SLE patients with and without LN. The regions of those gels corresponding to reactive bands observed with sera from LN patients were analyzed using LC-MS/MS. RESULTS LN reactive bands were seen at approximately 50 kDa in podocyte extracts and between 36 and 50 kDa in glomerular extracts. Those bands were analyzed by LC-MS/MS and 102 overlapping proteins were identified. Bioinformatic analysis determined that 36 of those proteins were membrane associated, including a protein previously suggested to contribute to glomerulonephritis and LN, annexin A2. By ELISA, patients with proliferative LN demonstrated significantly increased antibodies against annexin A2. CONCLUSION AND CLINICAL RELEVANCE Proteomic approaches identified multiple candidate antigens for autoantibodies in patients with LN. Serum antibodies against annexin A2 were significantly elevated in subjects with proliferative LN, validating those antibodies as potential biomarkers.
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Affiliation(s)
- Dawn J Caster
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA.,Robley Rex Veterans Affairs Medical Center, Louisville, KY, USA
| | - Erik A Korte
- Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Michael L Merchant
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA
| | - Jon B Klein
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA.,Robley Rex Veterans Affairs Medical Center, Louisville, KY, USA
| | - Daniel W Wilkey
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA
| | - Brad H Rovin
- Department of Medicine, the Ohio State University, Columbus, OH, USA
| | - Dan J Birmingham
- Department of Medicine, the Ohio State University, Columbus, OH, USA
| | - John B Harley
- Center for Autoimmune Genomics and Etiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, Cincinnati, OH, USA.,US Department of Veterans Affairs Medical Center, Cincinnati, OH, USA
| | - Beth L Cobb
- Center for Autoimmune Genomics and Etiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, Cincinnati, OH, USA
| | - Bahram Namjou
- Center for Autoimmune Genomics and Etiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, Cincinnati, OH, USA
| | - Kenneth R McLeish
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA.,Robley Rex Veterans Affairs Medical Center, Louisville, KY, USA
| | - David W Powell
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA.,Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY, USA
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30
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Huang L, Zou Y, Weng HW, Li HY, Liu JS, Yang WD. Proteomic profile in Perna viridis after exposed to Prorocentrum lima, a dinoflagellate producing DSP toxins. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 196:350-357. [PMID: 25463732 DOI: 10.1016/j.envpol.2014.10.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 10/09/2014] [Accepted: 10/15/2014] [Indexed: 06/04/2023]
Abstract
In the current study, we compared protein profiles in gills of Perna viridis after exposure to Prorocentrumlima, a dinoflagellate producing DSP toxins, and identified the differential abundances of protein spots using 2D-electrophoresis. After exposure to P. lima, the level of okadaic acid (a main component of DSP toxins) in gills of P. viridis significantly increased at 6 h, but mussels were all apparently healthy without death. Among the 28 identified protein spots by MALDI TOF/TOF-MS, 12 proteins were up-regulated and 16 were down-regulated in the P. lima-exposed mussels. These identified proteins were involved in various biological activities, such as metabolism, cytoskeleton, signal transduction, response to oxidative stress and detoxification. Taken together, our results indicated that the presence of P. lima caused DSP toxins accumulation in mussel gill, and might consequently induce cytoskeletonal disorganization,oxidative stress, a dysfunction in metabolism and ubiquitination/proteasome activity.
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Affiliation(s)
- Lu Huang
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China
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31
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Abstract
Osteoclastic bone resorption depends upon the cell's ability to organize its cytoskeleton. Because vinculin (VCL) is an actin-binding protein, we asked whether it participates in skeletal degradation. Thus, we mated VCL(fl/fl) mice with those expressing cathepsin K-Cre (CtsK-VCL) to delete the gene in mature osteoclasts or lysozyme M-Cre (LysM-VCL) to target all osteoclast lineage cells. VCL-deficient osteoclasts differentiate normally but, reflecting cytoskeletal disorganization, form small actin rings and fail to effectively resorb bone. In keeping with inhibited resorptive function, CtsK-VCL and LysM-VCL mice exhibit a doubling of bone mass. Despite cytoskeletal disorganization, the capacity of VCL(-/-) osteoclastic cells to normally phosphorylate c-Src in response to αvβ3 integrin ligand is intact. Thus, integrin-activated signals are unrelated to the means by which VCL organizes the osteoclast cytoskeleton. WT VCL completely rescues actin ring formation and bone resorption, as does VCL(P878A), which is incapable of interacting with Arp2/3. As expected, deletion of the VCL tail domain (VCL(1-880)), which binds actin, does not normalize VCL(-/-) osteoclasts. The same is true regarding VCL(I997A), which also prevents VCL/actin binding, and VCL(A50I) and VCL(811-1066), both of which arrest talin association. Thus, VCL binding talin, but not Arp2/3, is critical for osteoclast function, and its selective inhibition retards physiological bone loss.
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Microtubule dynamic instability controls podosome patterning in osteoclasts through EB1, cortactin, and Src. Mol Cell Biol 2013; 34:16-29. [PMID: 24144981 DOI: 10.1128/mcb.00578-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In osteoclasts (OCs) podosomes are organized in a belt, a feature critical for bone resorption. Although microtubules (MTs) promote the formation and stability of the belt, the MT and/or podosome molecules that mediate the interaction of the two systems are not identified. Because the growing "plus" ends of MTs point toward the podosome belt, plus-end tracking proteins (+TIPs) might regulate podosome patterning. Among the +TIPs, EB1 increased as OCs matured and was enriched in the podosome belt, and EB1-positive MTs targeted podosomes. Suppression of MT dynamic instability, displacement of EB1 from MT ends, or EB1 depletion resulted in the loss of the podosome belt. We identified cortactin as an Src-dependent interacting partner of EB1. Cortactin-deficient OCs presented a defective MT targeting to, and patterning of, podosomes and reduced bone resorption. Suppression of MT dynamic instability or EB1 depletion increased cortactin phosphorylation, decreasing its acetylation and affecting its interaction with EB1. Thus, dynamic MTs and podosomes interact to control bone resorption.
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33
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Schachtner H, Calaminus SDJ, Thomas SG, Machesky LM. Podosomes in adhesion, migration, mechanosensing and matrix remodeling. Cytoskeleton (Hoboken) 2013; 70:572-89. [PMID: 23804547 DOI: 10.1002/cm.21119] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/07/2013] [Accepted: 06/13/2013] [Indexed: 12/30/2022]
Abstract
Cells use various actin-based motile structures to allow them to move across and through matrix of varying density and composition. Podosomes are actin cytoskeletal structures that form in motile cells and that mediate adhesion to substrate, migration, and other specialized functions such as transmigration through cell and matrix barriers. The podosome is a unique and interesting entity, which appears in the light microscope as an individual punctum, but is linked to other podosomes like a node on a network of the underlying cytoskeleton. Here, we discuss the signals that control podosome assembly and dynamics in different cell types and the actin organising proteins that regulate both the inner actin core and integrin-rich surrounding ring structures. We review the structure and composition of podosomes and also their functions in various cell types of both myeloid and endothelial lineage. We also discuss the emerging idea that podosomes can sense matrix stiffness and enable cells to respond to their environment.
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Affiliation(s)
- Hannah Schachtner
- CRUK Beatson Institute for Cancer Research and College of Medical, Veterinary and Life Sciences, Glasgow University, Garscube Campus, Switchback Rd., Bearsden, Glasgow, United Kingdom
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34
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Schachtner H, Calaminus SDJ, Sinclair A, Monypenny J, Blundell MP, Leon C, Holyoake TL, Thrasher AJ, Michie AM, Vukovic M, Gachet C, Jones GE, Thomas SG, Watson SP, Machesky LM. Megakaryocytes assemble podosomes that degrade matrix and protrude through basement membrane. Blood 2013; 121:2542-52. [PMID: 23305739 DOI: 10.1182/blood-2012-07-443457] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Megakaryocytes give rise to platelets via extension of proplatelet arms, which are released through the vascular sinusoids into the bloodstream. Megakaryocytes and their precursors undergo varying interactions with the extracellular environment in the bone marrow during their maturation and positioning in the vascular niche. We demonstrate that podosomes are abundant in primary murine megakaryocytes adherent on multiple extracellular matrix substrates, including native basement membrane. Megakaryocyte podosome lifetime and density, but not podosome size, are dependent on the type of matrix, with podosome lifetime dramatically increased on collagen fibers compared with fibrinogen. Podosome stability and dynamics depend on actin cytoskeletal dynamics but not matrix metalloproteases. However, podosomes degrade matrix and appear to be important for megakaryocytes to extend protrusions across a native basement membrane. We thus demonstrate for the first time a fundamental requirement for podosomes in megakaryocyte process extension across a basement membrane, and our results suggest that podosomes may have a role in proplatelet arm extension or penetration of basement membrane.
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Affiliation(s)
- Hannah Schachtner
- University of Glasgow College of Medical, Veterinary and Life Sciences and Beatson Institute for Cancer Research, Bearsden, Glasgow, UK
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35
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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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36
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Wang Y, Grainger DW. RNA therapeutics targeting osteoclast-mediated excessive bone resorption. Adv Drug Deliv Rev 2012; 64:1341-57. [PMID: 21945356 DOI: 10.1016/j.addr.2011.09.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 09/05/2011] [Indexed: 01/13/2023]
Abstract
RNA interference (RNAi) is a sequence-specific post-transcriptional gene silencing technique developed with dramatically increasing utility for both scientific and therapeutic purposes. Short interfering RNA (siRNA) is currently exploited to regulate protein expression relevant to many therapeutic applications, and commonly used as a tool for elucidating disease-associated genes. Osteoporosis and their associated osteoporotic fragility fractures in both men and women are rapidly becoming a global healthcare crisis as average life expectancy increases worldwide. New therapeutics are needed for this increasing patient population. This review describes the diversity of molecular targets suitable for RNAi-based gene knock down in osteoclasts to control osteoclast-mediated excessive bone resorption. We identify strategies for developing targeted siRNA delivery and efficient gene silencing, and describe opportunities and challenges of introducing siRNA as a therapeutic approach to hard and connective tissue disorders.
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37
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Toro EJ, Zuo J, Ostrov DA, Catalfamo D, Bradaschia-Correa V, Arana-Chavez V, Caridad AR, Neubert JK, Wronski TJ, Wallet SM, Holliday LS. Enoxacin directly inhibits osteoclastogenesis without inducing apoptosis. J Biol Chem 2012; 287:17894-17904. [PMID: 22474295 DOI: 10.1074/jbc.m111.280511] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Enoxacin has been identified as a small molecule inhibitor of binding between the B2-subunit of vacuolar H+-ATPase (V-ATPase) and microfilaments. It inhibits bone resorption by calcitriol-stimulated mouse marrow cultures. We hypothesized that enoxacin acts directly and specifically on osteoclasts by disrupting the interaction between plasma membrane-directed V-ATPases, which contain the osteoclast-selective a3-subunit of V-ATPase, and microfilaments. Consistent with this hypothesis, enoxacin dose-dependently reduced the number of multinuclear cells expressing tartrate-resistant acid phosphatase (TRAP) activity produced by RANK-L-stimulated osteoclast precursors. Enoxacin (50 μM) did not induce apoptosis as measured by TUNEL and caspase-3 assays. V-ATPases containing the a3-subunit, but not the "housekeeping" a1-subunit, were isolated bound to actin. Treatment with enoxacin reduced the association of V-ATPase subunits with the detergent-insoluble cytoskeleton. Quantitative PCR revealed that enoxacin triggered significant reductions in several osteoclast-selective mRNAs, but levels of various osteoclast proteins were not reduced, as determined by quantitative immunoblots, even when their mRNA levels were reduced. Immunoblots demonstrated that proteolytic processing of TRAP5b and the cytoskeletal protein L-plastin was altered in cells treated with 50 μM enoxacin. Flow cytometry revealed that enoxacin treatment favored the expression of high levels of DC-STAMP on the surface of osteoclasts. Our data show that enoxacin directly inhibits osteoclast formation without affecting cell viability by a novel mechanism that involves changes in posttranslational processing and trafficking of several proteins with known roles in osteoclast function. We propose that these effects are downstream to blocking the binding interaction between a3-containing V-ATPases and microfilaments.
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Affiliation(s)
- Edgardo J Toro
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida 32610
| | - Jian Zuo
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida 32610
| | - David A Ostrov
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Dana Catalfamo
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida 32610
| | - Vivian Bradaschia-Correa
- Laboratory of Oral Biology, Department of Dental Materials, School of Dentistry, University of São Paulo, 05508-900 São Paulo SP, Brazil
| | - Victor Arana-Chavez
- Laboratory of Oral Biology, Department of Dental Materials, School of Dentistry, University of São Paulo, 05508-900 São Paulo SP, Brazil
| | - Aliana R Caridad
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida 32610
| | - John K Neubert
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida 32610
| | - Thomas J Wronski
- Department of Physiological Sciences, University of Florida, Gainesville, Florida 32610
| | - Shannon M Wallet
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida 32610
| | - L Shannon Holliday
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida 32610; Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida 32610.
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38
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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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39
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Abstract
Numerous studies indicate that microgravity affects cell growth and differentiation in many living organisms, and various processes are modified when cells are placed under conditions of weightlessness. However, until now, there is no coherent explanation for these observations, and little information is available concerning the biomolecules involved. Our aim has been to investigate the protein pattern of Xenopus laevis embryos exposed to simulated microgravity during the first 6 days of development. A proteomic approach was applied to compare the protein profiles of Xenopus embryos developed in simulated microgravity and in normal conditions. Attention was focused on embryos that do not present visible malformations in order to investigate if weightlessness has effects at protein level in the absence of macroscopic alterations. The data presented strongly suggest that some of the major components of the cytoskeleton vary in such conditions. Three major findings are described for the first time: (i) the expression of important factors involved in the organization and stabilization of the cytoskeleton, such as Arp (actin-related protein) 3 and stathmin, is heavily affected by microgravity; (ii) the amount of the two major cytoskeletal proteins, actin and tubulin, do not change in such conditions; however, (iii) an increase in the tyrosine nitration of these two proteins can be detected. The data suggest that, in the absence of morphological alterations, simulated microgravity affects the intracellular movement system of cells by altering cytoskeletal proteins heavily involved in the regulation of cytoskeleton remodelling.
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40
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Novack DV, Faccio R. Osteoclast motility: putting the brakes on bone resorption. Ageing Res Rev 2011; 10:54-61. [PMID: 19788940 PMCID: PMC2888603 DOI: 10.1016/j.arr.2009.09.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 09/23/2009] [Accepted: 09/23/2009] [Indexed: 11/28/2022]
Abstract
As the skeleton ages, the balanced formation and resorption of normal bone remodeling is lost, and bone loss predominates. The osteoclast is the specialized cell that is responsible for bone resorption. It is a highly polarized cell that must adhere to the bone surface and migrate along it while resorbing, and cytoskeletal reorganization is critical. Podosomes, highly dynamic actin structures, mediate osteoclast motility. Resorbing osteoclasts form a related actin complex, the sealing zone, which provides the boundary for the resorptive microenvironment. Similar to podosomes, the sealing zone rearranges itself to allow continuous resorption while the cell is moving. The major adhesive protein controlling the cytoskeleton is αvβ3 integrin, which collaborates with the growth factor M-CSF and the ITAM receptor DAP12. In this review, we discuss the signaling complexes assembled by these molecules at the membrane, and their downstream mediators that control OC motility and function via the cytoskeleton.
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41
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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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42
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Analysis of the signaling pathways regulating Src-dependent remodeling of the actin cytoskeleton. Eur J Cell Biol 2010; 90:143-56. [PMID: 20719402 DOI: 10.1016/j.ejcb.2010.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 06/18/2010] [Accepted: 07/13/2010] [Indexed: 12/24/2022] Open
Abstract
Cell adhesion to the extracellular matrix is mediated by adhesion receptors, mainly integrins, which upon interaction with the extracellular matrix, bind to the actin cytoskeleton via their cytoplasmic domains. This association is mediated by a variety of scaffold and signaling proteins, which control the mechanical and signaling activities of the adhesion site. Upon transformation of fibroblasts with active forms of Src (e.g., v-Src), focal adhesions are disrupted, and transformed into dot-like contacts known as podosomes, and consisting of a central actin core surrounded by an adhesion ring. To clarify the mechanism underlying Src-dependent modulation of the adhesive phenotype, and its influence on podosome organization, we screened for the effect of siRNA-mediated knockdown of tyrosine kinases, MAP kinases and phosphatases on the reorganization of the adhesion-cytoskeleton complex, induced by a constitutively active Src mutant (SrcY527F). In this screen, we discovered several genes that are involved in Src-induced remodeling of the actin cytoskeleton. We further showed that knockdown of Src in osteoclasts abolishes the formation of the podosome-based rings and impairs cell spreading, without inducing stress fiber development. Our work points to several genes that are involved in this process, and sheds new light on the molecular plasticity of integrin adhesions.
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43
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Ma T, Sadashivaiah K, Madayiputhiya N, Chellaiah MA. Regulation of sealing ring formation by L-plastin and cortactin in osteoclasts. J Biol Chem 2010; 285:29911-24. [PMID: 20650888 DOI: 10.1074/jbc.m109.099697] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The aim of this study is to identify the exact mechanism(s) by which cytoskeletal structures are modulated during bone resorption. In this study, we have shown the possible role of different actin-binding and signaling proteins in the regulation of sealing ring formation. Our analyses have demonstrated a significant increase in cortactin and a corresponding decrease in L-plastin protein levels in osteoclasts subjected to bone resorption for 18 h in the presence of RANKL, M-CSF, and native bone particles. Time-dependent changes in the localization of L-plastin (in actin aggregates) and cortactin (in the sealing ring) suggest that these proteins may be involved in the initial and maturation phases of sealing ring formation, respectively. siRNA to cortactin inhibits this maturation process but not the formation of actin aggregates. Osteoclasts treated as above but with TNF-α demonstrated very similar effects as observed with RANKL. Osteoclasts treated with a neutralizing antibody to TNF-α displayed podosome-like structures in the entire subsurface and at the periphery of osteoclast. It is possible that TNF-α and RANKL-mediated signaling may play a role in the early phase of sealing ring configuration (i.e. either in the disassembly of podosomes or formation of actin aggregates). Furthermore, osteoclasts treated with alendronate or αv reduced the formation of the sealing ring but not actin aggregates. The present study demonstrates a novel mechanistic link between L-plastin and cortactin in sealing ring formation. These results suggest that actin aggregates formed by L-plastin independent of integrin signaling function as a core in assembling signaling molecules (integrin αvβ3, Src, cortactin, etc.) involved in the maturation process.
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Affiliation(s)
- Tao Ma
- Department of Oncology and Diagnostic Sciences, Dental School, University of Maryland, Baltimore, Maryland 21201, USA
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44
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Molli PR, Li DQ, Bagheri-Yarmand R, Pakala SB, Katayama H, Sen S, Iyer J, Chernoff J, Tsai MY, Nair SS, Kumar R. Arpc1b, a centrosomal protein, is both an activator and substrate of Aurora A. ACTA ACUST UNITED AC 2010; 190:101-14. [PMID: 20603326 PMCID: PMC2911675 DOI: 10.1083/jcb.200908050] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In addition to its function as an Arp2/3 complex subunit, Arp1cb interacts with and stimulates Aurora A at centrosomes, functioning in cell cycle progression. Here we provide evidence in support of an inherent role for Arpc1b, a component of the Arp2/3 complex, in regulation of mitosis and demonstrate that its depletion inhibits Aurora A activation at the centrosome and impairs the ability of mammalian cells to enter mitosis. We discovered that Arpc1b colocalizes with γ-tubulin at centrosomes and stimulates Aurora A activity. Aurora A phosphorylates Arpc1b on threonine 21, and expression of Arpc1b but not a nonphosphorylatable Arpc1b mutant in mammalian cells leads to Aurora A kinase activation and abnormal centrosome amplification in a Pak1-independent manner. Together, these findings reveal a new function for Arpc1b in centrosomal homeostasis. Arpc1b is both a physiological activator and substrate of Aurora A kinase and these interactions help to maintain mitotic integrity in mammalian cells.
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Affiliation(s)
- Poonam R Molli
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC 20037, USA
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45
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Ito Y, Teitelbaum SL, Zou W, Zheng Y, Johnson JF, Chappel J, Ross FP, Zhao H. Cdc42 regulates bone modeling and remodeling in mice by modulating RANKL/M-CSF signaling and osteoclast polarization. J Clin Invest 2010; 120:1981-93. [PMID: 20501942 DOI: 10.1172/jci39650] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Accepted: 02/24/2010] [Indexed: 11/17/2022] Open
Abstract
The modeling and remodeling of bone requires activation and polarization of osteoclasts, achieved by reorganization of the cytoskeleton. Members of the Rho subfamily of small GTPases, including Cdc42, are known regulators of cytoskeletal components, but the role of these proteins in bone physiology and pathophysiology remains unclear. Here, we examined loss-of-function mice in which Cdc42 was selectively ablated in differentiated osteoclasts and gain-of-function animals wherein Cdc42Gap, a protein that inactivates the small GTPase, was deleted globally. Cdc42 loss-of-function mice were osteopetrotic and resistant to ovariectomy-induced bone loss, while gain-of-function animals were osteoporotic. Isolated Cdc42-deficient osteoclasts displayed suppressed bone resorption, while osteoclasts with increased Cdc42 activity had enhanced resorptive capacity. We further demonstrated that Cdc42 modulated M-CSF-stimulated cyclin D expression and phosphorylation of Rb and induced caspase 3 and Bim, thus contributing to osteoclast proliferation and apoptosis rates. Furthermore, Cdc42 was required for multiple M-CSF- and RANKL-induced osteoclastogenic signals including activation and expression of the differentiation factors MITF and NFATc1 and was a component of the Par3/Par6/atypical PKC polarization complex in osteoclasts. These data suggest that Cdc42 regulates osteoclast formation and function and may represent a promising therapeutic target for prevention of pathological bone loss.
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Affiliation(s)
- Yuji Ito
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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46
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Albiges-Rizo C, Destaing O, Fourcade B, Planus E, Block MR. Actin machinery and mechanosensitivity in invadopodia, podosomes and focal adhesions. J Cell Sci 2009; 122:3037-49. [PMID: 19692590 DOI: 10.1242/jcs.052704] [Citation(s) in RCA: 252] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The invasiveness of cells is correlated with the presence of dynamic actin-rich membrane structures called invadopodia, which are membrane protrusions that are associated with localized polymerization of sub-membrane actin filaments. Similar to focal adhesions and podosomes, invadopodia are cell-matrix adhesion sites. Indeed, invadopodia share several features with podosomes, but whether they are distinct structures is still a matter of debate. Invadopodia are built upon an N-WASP-dependent branched actin network, and the Rho GTPase Cdc42 is involved in inducing invadopodial-membrane protrusion, which is mediated by actin filaments that are organized in bundles to form an actin core. Actin-core formation is thought to be an early step in invadopodium assembly, and the actin core is perpendicular to the extracellular matrix and the plasma membrane; this contrasts with the tangential orientation of actin stress fibers anchored to focal adhesions. In this Commentary, we attempt to summarize recent insights into the actin dynamics of invadopodia and podosomes, and the forces that are transmitted through these invasive structures. Although the mechanisms underlying force-dependent regulation of invadopodia and podosomes are largely unknown compared with those of focal adhesions, these structures do exhibit mechanosensitivity. Actin dynamics and associated forces might be key elements in discriminating between invadopodia, podosomes and focal adhesions. Targeting actin-regulatory molecules that specifically promote invadopodium formation is an attractive strategy against cancer-cell invasion.
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Affiliation(s)
- Corinne Albiges-Rizo
- INSERM U823 Institut Albert Bonniot, Université Joseph Fourier, CNRS ERL3148, Equipe DySAD, Site Santé, BP 170, Grenoble, France.
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47
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Schroth-Diez B, Gerwig S, Ecke M, Hegerl R, Diez S, Gerisch G. Propagating waves separate two states of actin organization in living cells. HFSP JOURNAL 2009; 3:412-27. [PMID: 20514132 DOI: 10.2976/1.3239407] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 09/08/2009] [Indexed: 12/29/2022]
Abstract
Propagating actin waves are dynamic supramolecular structures formed by the self-assembly of proteins within living cells. They are built from actin filaments together with single-headed myosin, the Arp23 complex, and coronin in a defined three-dimensional order. The function of these waves in structuring the cell cortex is studied on the substrate-attached surface of Dictyostelium cells by the use of total internal reflection fluorescence (TIRF) microscopy. Actin waves separate two areas of the cell cortex from each other, which are distinguished by the arrangement of actin filaments. The Arp23 complex dominates in the area enclosed by a wave, where it has the capacity of building dendritic structures, while the proteins prevailing in the external area, cortexillin I and myosin-II, bundle actin filaments and arrange them in antiparallel direction. Wave propagation is accompanied by transitions in the state of actin with a preferential period of 5 min. Wave generation is preceded by local fluctuations in actin assembly, some of the nuclei of polymerized actin emanating from clathrin-coated structures, others emerging independently. The dynamics of phase transitions has been analyzed to provide a basis for modeling the nonlinear interactions that produce spatio-temporal patterns in the actin system of living cells.
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Abstract
Changes in the morphology of a dendritic spine require remodeling of its actin-based cytoskeleton. Biochemical mechanisms underlying actin remodeling have been studied extensively, but little is known about the physical organization of the actin-binding proteins that mediate remodeling in spines. Long-term potentiation-inducing stimuli trigger expansion of the spine head, suggesting local extension and branching of actin filaments. Because filament branching requires the Arp2/3 complex, we used quantitative immunoelectron microscopy to elucidate the organization of ARPC-2 (Arp2/3 complex subunit 2), an essential component of the complex. Our data from CA1 hippocampus indicate that Arp2/3 concentrates within spines in a previously unrecognized torroidal domain, apparently specialized to mediate actin filament branching.
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Listeria comet tails: the actin-based motility machinery at work. Trends Cell Biol 2008; 18:220-7. [DOI: 10.1016/j.tcb.2008.03.001] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 03/01/2008] [Accepted: 03/03/2008] [Indexed: 11/21/2022]
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Morikawa K, Goto T, Tanimura A, Kobayashi S, Maki K. Distribution of inositol 1,4,5-trisphosphate receptors in rat osteoclasts. Acta Histochem Cytochem 2008; 41:7-13. [PMID: 18493589 PMCID: PMC2386513 DOI: 10.1267/ahc.07027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 03/12/2008] [Indexed: 01/15/2023] Open
Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are Ca2+ channels that localize to intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Recently, IP3Rs were found to participate in the formation of the cytoskeleton and cellular adhesions. In this study, we examined the cellular localization of type I, II, and III IP3Rs to assess their role in cellular adhesion in rat osteoclasts. Rat bone marrow cells were cultured in α-MEM with 10% fetal bovine serum, M-CSF, RANKL, and 1,25(OH)2D3 for 1 week to promote osteoclast formation. Type I, II, and III IP3R expression in the osteoclasts was then examined by RT-PCR. Double-staining was performed using antibodies against type I, II, and III IP3Rs and DiOC6, an ER marker, or TRITC-phalloidin, an actin filament marker. Expression of all three IP3Rs was detected in the newly formed osteoclasts; however, the localization of the type I and II IP3Rs was predominantly close to nuclear, and possibly colocalized with the ER, while the type III IP3Rs were localized to the ER and podosomes, actin-rich adhesion structures in osteoclasts. These findings suggest that type III IP3Rs are associated with osteoclast adhesion.
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Affiliation(s)
- Kazumasa Morikawa
- Division of Developmental Stomatognathic Function Science, Kyushu Dental College
| | - Tetsuya Goto
- Division of Anatomy, Kyushu Dental College, Kitakyushu 803–8580, Japan
| | - Akihiko Tanimura
- Division of Pharmacology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061–0293, Japan
| | - Shigeru Kobayashi
- Division of Anatomy, Kyushu Dental College, Kitakyushu 803–8580, Japan
| | - Kenshi Maki
- Division of Developmental Stomatognathic Function Science, Kyushu Dental College
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