1
|
Yang X, Chen M, Wang S, Hu X, Zhou J, Yuan H, Zhu E, Wang B. Cortactin controls bone homeostasis through regulating the differentiation of osteoblasts and osteoclasts. Stem Cells 2024; 42:662-674. [PMID: 38655781 DOI: 10.1093/stmcls/sxae031] [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: 12/10/2023] [Accepted: 04/10/2024] [Indexed: 04/26/2024]
Abstract
Cortactin (CTTN), a cytoskeletal protein and substrate of Src kinase, is implicated in tumor aggressiveness. However, its role in bone cell differentiation remains unknown. The current study revealed that CTTN was upregulated during osteoblast and adipocyte differentiation. Functional experiments demonstrated that CTTN promoted the in vitro differentiation of mesenchymal stem/progenitor cells into osteogenic and adipogenic lineages. Mechanistically, CTTN was able to stabilize the protein level of mechanistic target of rapamycin kinase (mTOR), leading to the activation of mTOR signaling. In-depth investigation revealed that CTTN could bind with casitas B lineage lymphoma-c (c-CBL) and counteract the function of c-CBL, a known E3 ubiquitin ligase responsible for the proteasomal degradation of mTOR. Silencing c-Cbl alleviated the impaired differentiation of osteoblasts and adipocytes caused by CTTN siRNA, while silencing mTOR mitigated the stimulation of osteoblast and adipocyte differentiation induced by CTTN overexpression. Notably, transplantation of CTTN-silenced bone marrow stromal cells (BMSCs) into the marrow of mice led to a reduction in trabecular bone mass, accompanied by a decrease in osteoblasts and an increase in osteoclasts. Furthermore, CTTN-silenced BMSCs expressed higher levels of receptor activator of nuclear factor κB ligand (RANKL) than control BMSCs did and promoted osteoclast differentiation when cocultured with bone marrow-derived osteoclast precursor cells. This study provides evidence that CTTN favors osteoblast differentiation by counteracting the c-CBL-induced degradation of mTOR and inhibits osteoclast differentiation by downregulating the expression of RANKL. It also suggests that maintaining an appropriate level of CTTN expression may be advantageous for maintaining bone homeostasis.
Collapse
Affiliation(s)
- Xiaoli Yang
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| | - Meng Chen
- Department of hematology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, People's Republic of China
| | - Shuang Wang
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| | - Xingli Hu
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| | - Jie Zhou
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| | - Hairui Yuan
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| | - Endong Zhu
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| | - Baoli Wang
- NHC Key Lab of Hormones and Development, Tianjin Key Lab of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, People's Republic of China
| |
Collapse
|
2
|
Linder S, Barcelona B. Get a grip: Podosomes as potential players in phagocytosis. Eur J Cell Biol 2023; 102:151356. [PMID: 37625234 DOI: 10.1016/j.ejcb.2023.151356] [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] [Received: 06/23/2023] [Revised: 07/27/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023] Open
Abstract
Podosomes have been known for several decades as micron-sized, F-actin-rich structures that play a pivotal role in cell migration and invasion, as they are able to mediate both cell-matrix attachment as well as extracellular matrix degradation. Particularly in monocytic cells, podosomes have been shown to fulfill a variety of additional functions such as sensing of substrate rigidity and topography, or cell-cell fusion. Increasing evidence now points to the involvement of podosome-like structures also during phagocytosis by immune cells such as macrophages, dendritic cells, and neutrophils. Here, we compare the different cell models and experimental set ups where "phagocytic podosomes" have been described. We also discuss the composition and architecture of these structures, their potential involvement in mechanosensing and particle disruption, as well as the pros and cons for addressing them as bona fide podosomes.
Collapse
Affiliation(s)
- Stefan Linder
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Eppendorf, 20246 Hamburg, Germany.
| | - Bryan Barcelona
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Eppendorf, 20246 Hamburg, Germany
| |
Collapse
|
3
|
Hou J, Liu J, Huang Z, Wang Y, Yao H, Hu Z, Shi C, Xu J, Wang Q. Structure and function of the membrane microdomains in osteoclasts. Bone Res 2023; 11:61. [PMID: 37989999 PMCID: PMC10663511 DOI: 10.1038/s41413-023-00294-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 11/23/2023] Open
Abstract
The cell membrane structure is closely related to the occurrence and progression of many metabolic bone diseases observed in the clinic and is an important target to the development of therapeutic strategies for these diseases. Strong experimental evidence supports the existence of membrane microdomains in osteoclasts (OCs). However, the potential membrane microdomains and the crucial mechanisms underlying their roles in OCs have not been fully characterized. Membrane microdomain components, such as scaffolding proteins and the actin cytoskeleton, as well as the roles of individual membrane proteins, need to be elucidated. In this review, we discuss the compositions and critical functions of membrane microdomains that determine the biological behavior of OCs through the three main stages of the OC life cycle.
Collapse
Affiliation(s)
- Jialong Hou
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jian Liu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhixian Huang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yining Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Hanbing Yao
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhenxin Hu
- Department of Spine Surgery, Peking University Fourth School of Clinical Medicine, Beijing, China
| | - Chengge Shi
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jiake Xu
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia.
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
| | - Qingqing Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
- Department of Orthopaedics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
| |
Collapse
|
4
|
Fu J, Li S, Ma H, Yang J, Pagnotti GM, Brown LM, Weiss SJ, Mapara MY, Lentzsch S. The checkpoint inhibitor PD-1H/VISTA controls osteoclast-mediated multiple myeloma bone disease. Nat Commun 2023; 14:4271. [PMID: 37460553 DOI: 10.1038/s41467-023-39769-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 06/27/2023] [Indexed: 07/20/2023] Open
Abstract
Multiple myeloma bone disease is characterized by the development of osteolytic bone lesions. Recent work identified matrix metalloproteinase 13 as a myeloma-derived fusogen that induces osteoclast activation independent of its proteolytic activity. We now identify programmed death-1 homolog, PD-1H, as the bona fide MMP-13 receptor on osteoclasts. Silencing PD-1H or using Pd-1h-/- bone marrow cells abrogates the MMP-13-enhanced osteoclast fusion and bone-resorptive activity. Further, PD-1H interacts with the actin cytoskeleton and plays a necessary role in supporting c-Src activation and sealing zone formation. The critical role of PD-1H in myeloma lytic bone lesions was confirmed using a Pd-1h-/- myeloma bone disease mouse model wherein myeloma cells injected into Pd-1h-/-Rag2-/- results in attenuated bone destruction. Our findings identify a role of PD-1H in bone biology independent of its known immunoregulatory functions and suggest that targeting the MMP-13/PD-1H axis may represent a potential approach for the treatment of myeloma associated osteolysis.
Collapse
Affiliation(s)
- Jing Fu
- Columbia University Irving Medical Center, Department of Medicine, New York, NY, USA
| | - Shirong Li
- Columbia University Irving Medical Center, Department of Medicine, New York, NY, USA
| | - Huihui Ma
- Columbia University Irving Medical Center, Department of Medicine, New York, NY, USA
- Columbia Center for Translational Immunology, New York, NY, USA
| | - Jun Yang
- Columbia University Irving Medical Center, Department of Medicine, New York, NY, USA
| | - Gabriel M Pagnotti
- Indiana University, Indianapolis, IN, USA
- University of Texas-MD Anderson Cancer Center, Houston, TX, USA
| | - Lewis M Brown
- Quantitative Proteomics and Metabolomics Center, Columbia University, New York, NY, USA
| | - Stephen J Weiss
- Department of Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Markus Y Mapara
- Columbia University Irving Medical Center, Department of Medicine, New York, NY, USA
- Columbia Center for Translational Immunology, New York, NY, USA
| | - Suzanne Lentzsch
- Columbia University Irving Medical Center, Department of Medicine, New York, NY, USA.
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
Linder S, Cervero P, Eddy R, Condeelis J. Mechanisms and roles of podosomes and invadopodia. Nat Rev Mol Cell Biol 2023; 24:86-106. [PMID: 36104625 DOI: 10.1038/s41580-022-00530-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2022] [Indexed: 01/28/2023]
Abstract
Cell invasion into the surrounding extracellular matrix or across tissue boundaries and endothelial barriers occurs in both physiological and pathological scenarios such as immune surveillance or cancer metastasis. Podosomes and invadopodia, collectively called 'invadosomes', are actin-based structures that drive the proteolytic invasion of cells, by forming highly regulated platforms for the localized release of lytic enzymes that degrade the matrix. Recent advances in high-resolution microscopy techniques, in vivo imaging and high-throughput analyses have led to considerable progress in understanding mechanisms of invadosomes, revealing the intricate inner architecture of these structures, as well as their growing repertoire of functions that extends well beyond matrix degradation. In this Review, we discuss the known functions, architecture and regulatory mechanisms of podosomes and invadopodia. In particular, we describe the molecular mechanisms of localized actin turnover and microtubule-based cargo delivery, with a special focus on matrix-lytic enzymes that enable proteolytic invasion. Finally, we point out topics that should become important in the invadosome field in the future.
Collapse
Affiliation(s)
- Stefan Linder
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Eppendorf, Hamburg, Germany.
| | - Pasquale Cervero
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Eppendorf, Hamburg, Germany
| | - Robert Eddy
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, USA
| | - John Condeelis
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA.
| |
Collapse
|
7
|
Lim S, Ihn HJ, Kim JA, Bae JS, Kim JE, Bae YC, Shin HI, Kim TH, Park EK. Suppressive effects of (-)-tubaic acid on RANKL-induced osteoclast differentiation and bone resorption. Anim Cells Syst (Seoul) 2023; 27:1-9. [PMID: 36704446 PMCID: PMC9873279 DOI: 10.1080/19768354.2023.2166107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Regulation of osteoclastogenesis and bone-resorbing activity can be an efficacious strategy for treating bone loss diseases because excessive osteoclastic bone resorption leads to the development of such diseases. Here, we investigated the role of (-)-tubaic acid, a thermal degradation product of rotenone, in osteoclast formation and function in an attempt to identify alternative natural compounds. (-)-Tubaic acid significantly inhibited receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclast differentiation at both the early and late stages, suggesting that (-)-tubaic acid affects the commitment and differentiation of osteoclast progenitors as well as the cell-cell fusion of mononuclear osteoclasts. (-)-Tubaic acid attenuated the activation of extracellular signal-regulated kinase (ERK) and expression of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) and its target genes in response to RANKL. Furthermore, a pit-formation assay revealed that (-)-tubaic acid significantly impaired the bone-resorbing activity of osteoclasts. Our results demonstrated that (-)-tubaic acid exhibits anti-osteoclastogenic and anti-resorptive effects, indicating its therapeutic potential in the management of osteoclast-related bone diseases.
Collapse
Affiliation(s)
- Soomin Lim
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, IHBR, Kyungpook National University, Daegu, Republic of Korea
| | - Hye Jung Ihn
- Cell and Matrix Research Institute (CMRI), Kyungpook National University, Daegu, Republic of Korea
| | - Ju Ang Kim
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, IHBR, Kyungpook National University, Daegu, Republic of Korea
| | - Jong-Sup Bae
- College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Jung-Eun Kim
- Department of Molecular Medicine, CMRI, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Yong Chul Bae
- Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Hong-In Shin
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, IHBR, Kyungpook National University, Daegu, Republic of Korea
| | - Tae Hoon Kim
- Department of Food Science and Biotechnology, Daegu University, Gyeongsan, Republic of Korea
| | - Eui Kyun Park
- Department of Oral Pathology and Regenerative Medicine, School of Dentistry, IHBR, Kyungpook National University, Daegu, Republic of Korea, Eui Kyun Park Department of Oral Pathology and Regenerative Medicine, School of Dentistry, IHBR, Kyungpook National University, Daegu, Republic of Korea; Tae Hoon Kim Department of Food Science and Biotechnology, Daegu University, Gyeongsan, Republic of Korea
| |
Collapse
|
8
|
Krendel M, Gauthier NC. Building the phagocytic cup on an actin scaffold. Curr Opin Cell Biol 2022; 77:102112. [PMID: 35820329 PMCID: PMC10078615 DOI: 10.1016/j.ceb.2022.102112] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/26/2022] [Accepted: 06/07/2022] [Indexed: 12/17/2022]
Abstract
Cells ingest large particles, such as bacteria, viruses, or apoptotic cells, via the process of phagocytosis, which involves formation of an actin-rich structure known as the phagocytic cup. Phagocytic cup assembly and closure results from a concerted action of phagocytic receptors, regulators of actin polymerization, and myosin motors. Recent studies using advanced imaging approaches and biophysical techniques have revealed new information regarding phagocytic cup architecture, regulation of actin assembly, and the distribution, direction, and magnitude of the forces produced by the cytoskeletal elements that form the cup. These findings provide insights into the mechanisms leading to the assembly, expansion, and closure of phagocytic cups. The new data show that engulfment and internalization of phagocytic targets rely on several distinct yet complementary mechanisms that support the robust uptake of foreign objects and may be precisely tailored to the demands of specific phagocytic pathways.
Collapse
Affiliation(s)
- Mira Krendel
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY, 13210, USA.
| | - Nils C Gauthier
- IFOM, FIRC Institute of Molecular Oncology, Milan, 20139, Italy
| |
Collapse
|
9
|
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:e75610. [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] [MESH Headings] [Grants] [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 α-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.
Collapse
Affiliation(s)
- Marion Portes
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Thomas Mangeat
- LITC Core Facility, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Natacha Escallier
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Ophélie Dufrancais
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Brigitte Raynaud-Messina
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPSToulouseFrance
| | | | | | - Christel Vérollet
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Renaud Poincloux
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPSToulouseFrance
| |
Collapse
|
10
|
Matsubara T, Yasuda K, Mizuta K, Kawaue H, Kokabu S. Tyrosine Kinase Src Is a Regulatory Factor of Bone Homeostasis. Int J Mol Sci 2022; 23:ijms23105508. [PMID: 35628319 PMCID: PMC9146043 DOI: 10.3390/ijms23105508] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 11/16/2022] Open
Abstract
Osteoclasts, which resorb the bone, and osteoblasts, which form the bone, are the key cells regulating bone homeostasis. Osteoporosis and other metabolic bone diseases occur when osteoclast-mediated bone resorption is increased and bone formation by osteoblasts is decreased. Analyses of tyrosine kinase Src-knockout mice revealed that Src is essential for bone resorption by osteoclasts and suppresses bone formation by osteoblasts. Src-knockout mice exhibit osteopetrosis. Therefore, Src is a potential target for osteoporosis therapy. However, Src is ubiquitously expressed in many tissues and is involved in various biological processes, such as cell proliferation, growth, and migration. Thus, it is challenging to develop effective osteoporosis therapies targeting Src. To solve this problem, it is necessary to understand the molecular mechanism of Src function in the bone. Src expression and catalytic activity are maintained at high levels in osteoclasts. The high activity of Src is essential for the attachment of osteoclasts to the bone matrix and to resorb the bone by regulating actin-related molecules. Src also inhibits the activity of Runx2, a master regulator of osteoblast differentiation, suppressing bone formation in osteoblasts. In this paper, we introduce the molecular mechanisms of Src in osteoclasts and osteoblasts to explore its potential for bone metabolic disease therapy.
Collapse
|
11
|
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.
Collapse
Affiliation(s)
- Meenakshi A Chellaiah
- Department of Oncology and Diagnostic Sciences, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA
| |
Collapse
|
12
|
Delaisse JM, Søe K, Andersen TL, Rojek AM, Marcussen N. The Mechanism Switching the Osteoclast From Short to Long Duration Bone Resorption. Front Cell Dev Biol 2021; 9:644503. [PMID: 33859985 PMCID: PMC8042231 DOI: 10.3389/fcell.2021.644503] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/22/2021] [Indexed: 12/28/2022] Open
Abstract
The current models of osteoclastic bone resorption focus on immobile osteoclasts sitting on the bone surface and drilling a pit into the bone matrix. It recently appeared that many osteoclasts also enlarge their pit by moving across the bone surface while resorbing. Drilling a pit thus represents only the start of a resorption event of much larger amplitude. This prolonged resorption activity significantly contributes to pathological bone destruction, but the mechanism whereby the osteoclast engages in this process does not have an answer within the standard bone resorption models. Herein, we review observations that lead to envision how prolonged resorption is possible through simultaneous resorption and migration. According to the standard pit model, the “sealing zone” which surrounds the ruffled border (i.e., the actual resorption apparatus), “anchors” the ruffled border against the bone surface to be resorbed. Herein, we highlight that continuation of resorption demands that the sealing zone “glides” inside the cavity. Thereby, the sealing zone emerges as the structure responsible for orienting and displacing the ruffled border, e.g., directing resorption against the cavity wall. Importantly, sealing zone displacement stringently requires thorough collagen removal from the cavity wall - which renders strong cathepsin K collagenolysis indispensable for engagement of osteoclasts in cavity-enlargement. Furthermore, the sealing zone is associated with generation of new ruffled border at the leading edge, thereby allowing the ruffled border to move ahead. The sealing zone and ruffled border displacements are coordinated with the migration of the cell body, shown to be under control of lamellipodia at the leading edge and of the release of resorption products at the rear. We propose that bone resorption demands more attention to osteoclastic models integrating resorption and migration activities into just one cell phenotype.
Collapse
Affiliation(s)
- Jean-Marie Delaisse
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense, Denmark.,Clinical Cell Biology, Pathology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Kent Søe
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense, Denmark.,Clinical Cell Biology, Pathology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Thomas Levin Andersen
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense, Denmark.,Clinical Cell Biology, Pathology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Forensic Medicine, Aarhus University, Aarhus, Denmark
| | | | - Niels Marcussen
- Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
13
|
Lian Y, Wen D, Meng X, Wang X, Li H, Hao L, Xue H, Zhao J. Inhibition of invadopodia formation by diosgenin in tumor cells. Oncol Lett 2020; 20:283. [PMID: 33014161 PMCID: PMC7520800 DOI: 10.3892/ol.2020.12148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/15/2020] [Indexed: 12/11/2022] Open
Abstract
Diosgenin is a type of steroid extracted from the rhizome of Dioscorea plants. In traditional Chinese medicine, Dioscorea has the effect of ‘eliminating phlegm, promoting digestion, relaxing tendons, promoting blood circulation and inhibiting malaria’. Recent studies have confirmed that diosgenin exhibits a number of pharmacological effects, including antitumor activities. Through its antitumor effect, diosgenin is able to block tumor progression and increase the survival rate of patients with cancer; ultimately improving their quality of life. However, the mechanism underlying its pharmacological action remains unclear. Once tumor cells reach a metastatic phase, it can be fatal. Increased migration and invasiveness are the hallmarks of metastatic tumor cells. Invadopodia formation is key to maintaining the high migration and invasive ability of tumor cells. Invadopodia are a type of membrane structure process rich in filamentous-actin and are common in highly invasive tumor cells. In addition to actin, numerous actin regulators, including cortical actin-binding protein (Cortactin), accumulate in invadopodia. Cortactin is a microfilament actin-binding protein with special repetitive domains that are directly involved in the formation of the cortical microfilament actin cell skeleton. Cortactin is also one of the main substrates of intracellular Src-type tyrosine protein kinases and represents a highly conserved family of intracellular cortical signaling proteins. In recent years, great progress has been made in understanding the role of Cortactin and its molecular mechanism in cell motility. However, the diosgenin-Cortactin-invadopodia mechanism is still under investigation. Therefore, the present review focused on the current research on the regulation of invadopodia by diosgenin via Cortactin.
Collapse
Affiliation(s)
- Yaxin Lian
- Department of Histology and Embryology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Dezhong Wen
- Department of Medical Genetics, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Xiaoting Meng
- Department of Histology and Embryology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Xiaozhen Wang
- Department of Breast Surgery, The First Hospital, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Hongcheng Li
- GeneScience Pharmaceuticals Co., Ltd., Changchun, Jilin 130021, P.R. China
| | - Liming Hao
- Department of Histology and Embryology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Hui Xue
- Department of Histology and Embryology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jia Zhao
- Department of Histology and Embryology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| |
Collapse
|
14
|
Biber G, Ben-Shmuel A, Sabag B, Barda-Saad M. Actin regulators in cancer progression and metastases: From structure and function to cytoskeletal dynamics. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 356:131-196. [PMID: 33066873 DOI: 10.1016/bs.ircmb.2020.05.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cytoskeleton is a central factor contributing to various hallmarks of cancer. In recent years, there has been increasing evidence demonstrating the involvement of actin regulatory proteins in malignancy, and their dysregulation was shown to predict poor clinical prognosis. Although enhanced cytoskeletal activity is often associated with cancer progression, the expression of several inducers of actin polymerization is remarkably reduced in certain malignancies, and it is not completely clear how these changes promote tumorigenesis and metastases. The complexities involved in cytoskeletal induction of cancer progression therefore pose considerable difficulties for therapeutic intervention; it is not always clear which cytoskeletal regulator should be targeted in order to impede cancer progression, and whether this targeting may inadvertently enhance alternative invasive pathways which can aggravate tumor growth. The entire constellation of cytoskeletal machineries in eukaryotic cells are numerous and complex; the system is comprised of and regulated by hundreds of proteins, which could not be covered in a single review. Therefore, we will focus here on the actin cytoskeleton, which encompasses the biological machinery behind most of the key cellular functions altered in cancer, with specific emphasis on actin nucleating factors and nucleation-promoting factors. Finally, we discuss current therapeutic strategies for cancer which aim to target the cytoskeleton.
Collapse
Affiliation(s)
- G Biber
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - A Ben-Shmuel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - B Sabag
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - M Barda-Saad
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
| |
Collapse
|
15
|
Blangy A, Bompard G, Guerit D, Marie P, Maurin J, Morel A, Vives V. The osteoclast cytoskeleton - current understanding and therapeutic perspectives for osteoporosis. J Cell Sci 2020; 133:133/13/jcs244798. [PMID: 32611680 DOI: 10.1242/jcs.244798] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Osteoclasts are giant multinucleated myeloid cells specialized for bone resorption, which is essential for the preservation of bone health throughout life. The activity of osteoclasts relies on the typical organization of osteoclast cytoskeleton components into a highly complex structure comprising actin, microtubules and other cytoskeletal proteins that constitutes the backbone of the bone resorption apparatus. The development of methods to differentiate osteoclasts in culture and manipulate them genetically, as well as improvements in cell imaging technologies, has shed light onto the molecular mechanisms that control the structure and dynamics of the osteoclast cytoskeleton, and thus the mechanism of bone resorption. Although essential for normal bone physiology, abnormal osteoclast activity can cause bone defects, in particular their hyper-activation is commonly associated with many pathologies, hormonal imbalance and medical treatments. Increased bone degradation by osteoclasts provokes progressive bone loss, leading to osteoporosis, with the resulting bone frailty leading to fractures, loss of autonomy and premature death. In this context, the osteoclast cytoskeleton has recently proven to be a relevant therapeutic target for controlling pathological bone resorption levels. Here, we review the present knowledge on the regulatory mechanisms of the osteoclast cytoskeleton that control their bone resorption activity in normal and pathological conditions.
Collapse
Affiliation(s)
- Anne Blangy
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Guillaume Bompard
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - David Guerit
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Pauline Marie
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Justine Maurin
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Anne Morel
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| | - Virginie Vives
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000 Montpellier, France
| |
Collapse
|
16
|
Castellanos-Martínez R, Jiménez-Camacho KE, Schnoor M. Cortactin Expression in Hematopoietic Cells. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:958-967. [DOI: 10.1016/j.ajpath.2019.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/28/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
|
17
|
Matsubara T, Yaginuma T, Addison WN, Fujita Y, Watanabe K, Yoshioka I, Hikiji H, Maki K, Baron R, Kokabu S. Plectin stabilizes microtubules during osteoclastic bone resorption by acting as a scaffold for Src and Pyk2. Bone 2020; 132:115209. [PMID: 31866495 DOI: 10.1016/j.bone.2019.115209] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 10/25/2022]
Abstract
Osteoclasts are multinuclear cells which maintain bone homeostasis by resorbing bone. During bone resorption, osteoclasts attach to the bone matrix via a sealing zone formed by an actin ring. Rous sarcoma oncogene (Src) is essential for actin ring formation and bone resorption. Recently, we demonstrated that plectin, a cytolinker protein, is a Src-binding protein in osteoclasts. However, the function of plectin in osteoclasts remains unknown. In this study, we demonstrated that shRNA knockdown of plectin in RAW 264.7 cells resulted in tartrate resistant acid phosphatase positive multinuclear cells (TRAP (+) MNCs) with impaired actin ring formation and bone resorption activity. Moreover, we found that in plectin-silenced TRAP (+) MNCs, Src and protein tyrosine kinase 2 beta (Pyk2), two critical kinases in osteoclastic bone resorption, were inactivated and microtubule polarity was disturbed. These results suggest that plectin plays a critical role in osteoclast biology by acting as a scaffold to facilitate Src and Pyk2 activation during microtubule organization.
Collapse
Affiliation(s)
- Takuma Matsubara
- Division of Molecular Signaling and Biochemistry, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan.
| | - Tatsuki Yaginuma
- Division of Molecular Signaling and Biochemistry, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan; Division of Oral Medicine, Department of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - William N Addison
- Division of Molecular Signaling and Biochemistry, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan
| | - Yuko Fujita
- Division of Developmental Stomatognathic Function Science, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan
| | - Kouji Watanabe
- Division of Developmental Stomatognathic Function Science, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan
| | - Izumi Yoshioka
- Division of Oral Medicine, Department of Physical Functions, Kyushu Dental University, Kitakyushu, Japan
| | - Hisako Hikiji
- School of Oral Health Sciences, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan
| | - Kenshi Maki
- Division of Developmental Stomatognathic Function Science, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan
| | - Roland Baron
- Department of Medicine, Harvard Medical School and Division of Bone and Mineral Research, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, 188 Longwood Ave., Boston, MA 02115, USA
| | - Shoichiro Kokabu
- Division of Molecular Signaling and Biochemistry, Department of Health Promotion, Kyushu Dental University, 2-6-1, Manazuru, Kitakyushu, Fukuoka 8038580, Japan
| |
Collapse
|
18
|
Holliday LS, de Faria LP, Rody WJ. Actin and Actin-Associated Proteins in Extracellular Vesicles Shed by Osteoclasts. Int J Mol Sci 2019; 21:ijms21010158. [PMID: 31881680 PMCID: PMC6981389 DOI: 10.3390/ijms21010158] [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: 11/21/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EVs) are shed by all eukaryotic cells and have emerged as important intercellular regulators. EVs released by osteoclasts were recently identified as important coupling factors in bone remodeling. They are shed as osteoclasts resorb bone and stimulate osteoblasts to form bone to replace the bone resorbed. We reported the proteomic content of osteoclast EVs with data from two-dimensional, high resolution liquid chromatography/mass spectrometry. In this article, we examine in detail the actin and actin-associated proteins found in osteoclast EVs. Like EVs from other cell types, actin and various actin-associated proteins were abundant. These include components of the polymerization machinery, myosin mechanoenzymes, proteins that stabilize or depolymerize microfilaments, and actin-associated proteins that are involved in regulating integrins. The selective incorporation of actin-associated proteins into osteoclast EVs suggests that they have roles in the formation of EVs and/or the regulatory signaling functions of the EVs. Regulating integrins so that they bind extracellular matrix tightly, in order to attach EVs to the extracellular matrix at specific locations in organs and tissues, is one potential active role for actin-associated proteins in EVs.
Collapse
Affiliation(s)
- L. Shannon Holliday
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA
- Correspondence:
| | - 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;
| |
Collapse
|
19
|
Tehrani S, Davis L, Cepurna WO, Delf RK, Lozano DC, Choe TE, Johnson EC, Morrison JC. Optic Nerve Head Astrocytes Display Axon-Dependent and -Independent Reactivity in Response to Acutely Elevated Intraocular Pressure. Invest Ophthalmol Vis Sci 2019; 60:312-321. [PMID: 30665231 PMCID: PMC6343680 DOI: 10.1167/iovs.18-25447] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Purpose Optic nerve head (ONH) astrocytes provide support for axons, but exhibit structural and functional changes (termed reactivity) in a number of glaucoma models. The purpose of this study was to determine if ONH astrocyte structural reactivity is axon-dependent. Methods Using rats, we combine retrobulbar optic nerve transection (ONT) with acute controlled elevation of intraocular pressure (CEI), to induce total optic nerve axon loss and ONH astrocyte reactivity, respectively. Animals were euthanized immediately or 1 day post CEI, in the presence or absence of ONT. ONH sections were labeled with fluorescent-tagged phalloidin and antibodies against β3 tubulin, phosphorylated cortactin, phosphorylated paxillin, or complement C3. ONH label intensities were quantified after confocal microscopy. Retrobulbar nerves were assessed for axon injury by light microscopy. Results While ONT alone had no effect on ONH astrocyte structural orientation, astrocytes demonstrated significant reorganization of cellular extensions within hours after CEI, even when combined with ONT. However, ONH astrocytes displayed differential intensities of actin (phosphorylated cortactin) and focal adhesion (phosphorylated paxillin) mediators in response to CEI alone, ONT alone, or the combination of CEI and ONT. Lastly, label intensities of complement C3 within the ONH were unchanged in eyes subjected to CEI alone, ONT alone, or the combination of CEI and ONT, relative to controls. Conclusions Early ONH astrocyte structural reactivity to elevated IOP is multifaceted, displaying both axon dependent and independent responses. These findings have important implications for pursuing astrocytes as diagnostic and therapeutic targets in neurodegenerative disorders with fluctuating levels of axon injury.
Collapse
Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Lauren Davis
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - William O Cepurna
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - R Katherine Delf
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Diana C Lozano
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Tiffany E Choe
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - Elaine C Johnson
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| | - John C Morrison
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States
| |
Collapse
|
20
|
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.
Collapse
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.
| |
Collapse
|
21
|
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: 29] [Impact Index Per Article: 4.8] [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.
Collapse
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.
| |
Collapse
|
22
|
Tehrani S, Delf RK, Cepurna WO, Davis L, Johnson EC, Morrison JC. In Vivo Small Molecule Delivery to the Optic Nerve in a Rodent Model. Sci Rep 2018. [PMID: 29535357 PMCID: PMC5849600 DOI: 10.1038/s41598-018-22737-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Small molecule delivery to the optic nerve would allow for exploration of molecular and cellular pathways involved in normal physiology and optic neuropathies such as glaucoma, and provide a tool for screening therapeutics in animal models. We report a novel surgical method for small molecule drug delivery to the optic nerve head (ONH) in a rodent model. In proof-of-principle experiments, we delivered cytochalasin D (Cyt D; a filamentous actin inhibitor) to the junction of the superior optic nerve and globe in rats to target the actin-rich astrocytic cytoskeleton of the ONH. Cyt D delivery was quantified by liquid chromatography and mass spectrometry of isolated optic nerve tissue. One day after Cyt D delivery, anterior ONH filamentous actin bundle content was significantly reduced as assessed by fluorescent-tagged phalloidin labeling, relative to sham delivery. Anterior ONH nuclear counts and axon-specific beta-3 tubulin levels, as well as peripapillary retinal ganglion cell layer nuclear counts were not significantly altered after Cyt D delivery relative to sham delivery. Lastly, the surgical delivery technique caused minimal observable axon degeneration up to 10 days post-surgery. This small molecule delivery technique provides a new approach to studying optic neuropathies in in vivo rodent models.
Collapse
Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA.
| | - R Katherine Delf
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| | - William O Cepurna
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| | - Lauren Davis
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| | - Elaine C Johnson
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| | - John C Morrison
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
23
|
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.
Collapse
|
24
|
Abstract
Actin remodeling plays an essential role in diverse cellular processes such as cell motility, vesicle trafficking or cytokinesis. The scaffold protein and actin nucleation promoting factor Cortactin is present in virtually all actin-based structures, participating in the formation of branched actin networks. It has been involved in the control of endocytosis, and vesicle trafficking, axon guidance and organization, as well as adhesion, migration and invasion. To migrate and invade through three-dimensional environments, cells have developed specialized actin-based structures called invadosomes, a generic term to designate invadopodia and podosomes. Cortactin has emerged as a critical regulator of invadosome formation, function and disassembly. Underscoring this role, Cortactin is frequently overexpressed in several types of invasive cancers. Herein we will review the roles played by Cortactin in these specific invasive structures.
Collapse
Affiliation(s)
- Pauline Jeannot
- CRCT INSERM UMR1037, Université Toulouse III Paul Sabatier , CNRS ERL5294, Toulouse, France.,Cell Signalling Group, Cancer Research UK Manchester Institute, The University of Manchester , Manchester M20 4BX, UK
| | - Arnaud Besson
- CRCT INSERM UMR1037, Université Toulouse III Paul Sabatier , CNRS ERL5294, Toulouse, France.,LBCMCP , Centre de Biologie Intégrative, Université de Toulouse , CNRS, UPS, Toulouse Cedex, France
| |
Collapse
|
25
|
Yin M, Ma W, An L. Cortactin in cancer cell migration and invasion. Oncotarget 2017; 8:88232-88243. [PMID: 29152154 PMCID: PMC5675706 DOI: 10.18632/oncotarget.21088] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 08/29/2017] [Indexed: 12/20/2022] Open
Abstract
Cortactin, a substrate of sarcoma (Src) kinases, is an actin-binding protein that is involved in cytoskeletal regulation, and is frequently overexpressed in cancer cells. Binding to the actin related protein 2/3 (Arp2/3) complex stimulates cortactin activity, which promotes F-actin nucleation and assembly. Cortactin promotes cancer cell migration and invasion, and plays a pivotal role in invadopodia formation and extra cellular matrix degradation. Overexpression of cortactin, by amplification of the chromosomal band 11q13, increases tumor aggressiveness. In this review, we report on the current knowledge and potential mechanisms of action of cortactin as a critical mediator of cancer cell migration and invasion.
Collapse
Affiliation(s)
- Miao Yin
- Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Wenqing Ma
- Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Liguo An
- Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| |
Collapse
|
26
|
Park OJ, Kim J, Ahn KB, Lee JY, Park YJ, Kum KY, Yun CH, Han SH. A 15-amino acid C-terminal peptide of beta-defensin-3 inhibits bone resorption by inhibiting the osteoclast differentiation and disrupting podosome belt formation. J Mol Med (Berl) 2017; 95:1315-1325. [DOI: 10.1007/s00109-017-1589-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 08/22/2017] [Accepted: 08/29/2017] [Indexed: 02/05/2023]
|
27
|
Matsubara T, Kinbara M, Maeda T, Yoshizawa M, Kokabu S, Takano Yamamoto T. Regulation of osteoclast differentiation and actin ring formation by the cytolinker protein plectin. Biochem Biophys Res Commun 2017; 489:472-476. [DOI: 10.1016/j.bbrc.2017.05.174] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 05/29/2017] [Indexed: 11/25/2022]
|
28
|
Søe K, Delaissé JM. Time-lapse reveals that osteoclasts can move across the bone surface while resorbing. J Cell Sci 2017; 130:2026-2035. [PMID: 28473470 PMCID: PMC5482982 DOI: 10.1242/jcs.202036] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/28/2017] [Indexed: 12/29/2022] Open
Abstract
Bone erosion both demands that the osteoclast resorbs bone matrix and moves over the bone surface. It is widely accepted that these two activities alternate, because they are considered mutually exclusive since resorption is believed to involve an immobilizing seal to the bone surface. However, clear real-time observations are still lacking. Herein, we used specific markers and time-lapse to monitor live the spatiotemporal generation of resorption events by osteoclasts cultured on bone slices. In accordance with the current view, we found alternating episodes of resorption and migration resulting in the formation of clusters of round pits. However, very importantly, we also demonstrate that more than half of the osteoclasts moved laterally, displacing their extracellular bone-resorbing compartment over the bone surface without disassembling and reconstructing it, thereby generating long trenches. Compared to pit events, trench events show properties enabling higher aggressiveness: long duration (days), high erosion speed (two times faster) and long-distance erosion (several 100 µm). Simultaneous resorption and migration reflect a unique situation where epithelial/secretory and mesenchymal/migratory characteristics are integrated into just one cell phenotype, and deserves attention in future research. Summary: Bone erosion requires that osteoclasts both resorb and migrate. According to common belief, these activities are mutually exclusive and alternate. Paradoxically, we show here simultaneous resorption and migration.
Collapse
Affiliation(s)
- Kent Søe
- Department of Clinical Cell Biology, Vejle Hospital/Lillebaelt Hospital, Institute of Regional Health Research, University of Southern Denmark, 7100 Vejle, Denmark
| | - Jean-Marie Delaissé
- Department of Clinical Cell Biology, Vejle Hospital/Lillebaelt Hospital, Institute of Regional Health Research, University of Southern Denmark, 7100 Vejle, Denmark
| |
Collapse
|
29
|
Castillo LM, Guerrero CA, Acosta O. Expression of typical osteoclast markers by PBMCs after PEG-induced fusion as a model for studying osteoclast differentiation. J Mol Histol 2017; 48:169-185. [PMID: 28343338 DOI: 10.1007/s10735-017-9717-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/20/2017] [Indexed: 01/27/2023]
Abstract
Bone is a metabolically active organ subjected to continuous remodeling process that involves resorption by osteoclast and subsequent formation by osteoblasts. Osteoclast involvement in this physiological event is regulated by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κB ligand (RANKL). Fusion of mono-nuclear pre-osteoclasts is a critical event for osteoclast differentiation and for bone resorption. Here we show that PBMCs can be successfully fused with polyethylenglicol (PEG) in order to generated viable osteoclast-like cells that exhibit tartrate-resistant acid phosphatase (TRAP) and bone resorptive activities. PEG-fused PBMCs expressed additional markers compatible with osteoclastogenic differentiation such as carbonic anhydrase II (CAII), calcitonin receptor (CR), cathepsin K (Cat K), vacuolar ATPase (V-ATPase) subunit C1 (V-ATPase), integrin β3, RANK and cell surface aminopeptidase N/CD13. Actin redistribution in PEG-fused cells was found to be affected by cell cycle synchronization at G0/G1 or G2/M phases. PEG-induced fusion also led to expression of tyrosine kinases c-Src and Syk in their phosphorylated state. Scanning electron microscopy images showed morphological features typical of osteoclast-like cells. The results here shown allow concluding that PEG-induced fusion of PBMCs provides a suitable model system for understanding the mechanisms involved in osteoclastogenesis and for assaying new therapeutic strategies.
Collapse
Affiliation(s)
- Luz M Castillo
- Departamento de Ciencias Fisiológicas, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Carlos A Guerrero
- Departamento de Ciencias Fisiológicas, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia.
| | - Orlando Acosta
- Departamento de Ciencias Fisiológicas, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| |
Collapse
|
30
|
Pennanen P, Alanne MH, Fazeli E, Deguchi T, Näreoja T, Peltonen S, Peltonen J. Diversity of actin architecture in human osteoclasts: network of curved and branched actin supporting cell shape and intercellular micrometer-level tubes. Mol Cell Biochem 2017; 432:131-139. [PMID: 28293874 PMCID: PMC5532409 DOI: 10.1007/s11010-017-3004-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/04/2017] [Indexed: 12/17/2022]
Abstract
Osteoclasts are multinucleated bone-resorbing cells with a dynamic actin cytoskeleton. Osteoclasts are derived from circulating mononuclear precursors. Confocal and stimulated emission depletion (STED) super-resolution microscopy was used to investigate peripheral blood-derived human osteoclasts cultured on glass surfaces. STED and confocal microscopy demonstrated that the actin was curved and branched, for instance, in the vicinity of membrane ruffles. The overall architecture of the curved actin network extended from the podosomes to the top of the cell. The other novel finding was that a micrometer-level tube containing actin bridged the osteoclasts well above the level of the culture glass. The actin filaments of the tubes originated from the network of curved actin often surrounding a group of nuclei. Furthermore, nuclei were occasionally located inside the tubes. Our findings demonstrated the accumulation of c-Src, cortactin, cofilin, and actin around nuclei suggesting their role in nuclear processes such as the locomotion of nuclei. ARP2/3 labeling was abundant at the substratum level of osteoclasts and in the branched actin network, where it localized to the branching points. We speculate that the actin-containing tubes of osteoclasts may provide a means of transportation of nuclei, e.g., during the fusion of osteoclasts. These novel findings can pave the way for future studies aiming at the elucidation of the differentiation of multinucleated osteoclasts.
Collapse
Affiliation(s)
- Paula Pennanen
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland
| | - Maria Helena Alanne
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland
| | - Elnaz Fazeli
- Laboratory of Biophysics, Department of Cell Biology and Anatomy and Medicity Research Laboratories, University of Turku, P.O. Box 123, 20521, Turku, Finland
| | - Takahiro Deguchi
- Laboratory of Biophysics, Department of Cell Biology and Anatomy and Medicity Research Laboratories, University of Turku, P.O. Box 123, 20521, Turku, Finland
| | - Tuomas Näreoja
- Laboratory of Biophysics, Department of Cell Biology and Anatomy and Medicity Research Laboratories, University of Turku, P.O. Box 123, 20521, Turku, Finland
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Sirkku Peltonen
- Department of Dermatology, University of Turku and Turku University Hospital, PO BOX 52, 20521, Turku, Finland
| | - Juha Peltonen
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland.
| |
Collapse
|
31
|
Tehrani S, Davis L, Cepurna WO, Choe TE, Lozano DC, Monfared A, Cooper L, Cheng J, Johnson EC, Morrison JC. Astrocyte Structural and Molecular Response to Elevated Intraocular Pressure Occurs Rapidly and Precedes Axonal Tubulin Rearrangement within the Optic Nerve Head in a Rat Model. PLoS One 2016; 11:e0167364. [PMID: 27893827 PMCID: PMC5125687 DOI: 10.1371/journal.pone.0167364] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/12/2016] [Indexed: 02/01/2023] Open
Abstract
Glaucomatous axon injury occurs at the level of the optic nerve head (ONH) in response to uncontrolled intraocular pressure (IOP). The temporal response of ONH astrocytes (glial cells responsible for axonal support) to elevated IOP remains unknown. Here, we evaluate the response of actin-based astrocyte extensions and integrin-based signaling within the ONH to 8 hours of IOP elevation in a rat model. IOP elevation of 60 mm Hg was achieved under isoflurane anesthesia using anterior chamber cannulation connected to a saline reservoir. ONH astrocytic extension orientation was significantly and regionally rearranged immediately after IOP elevation (inferior ONH, 43.2° ± 13.3° with respect to the anterior-posterior axis versus 84.1° ± 1.3° in controls, p<0.05), and re-orientated back to baseline orientation 1 day post IOP normalization. ONH axonal microtubule filament label intensity was significantly reduced 1 and 3 days post IOP normalization, and returned to control levels on day 5. Phosphorylated focal adhesion kinase (FAK) levels steadily decreased after IOP normalization, while levels of phosphorylated paxillin (a downstream target of FAK involved in focal adhesion dynamics) were significantly elevated 5 days post IOP normalization. The levels of phosphorylated cortactin (a downstream target of Src kinase involved in actin polymerization) were significantly elevated 1 and 3 days post IOP normalization and returned to control levels by day 5. No significant axon degeneration was noted by morphologic assessment up to 5 days post IOP normalization. Actin-based astrocyte structure and signaling within the ONH are significantly altered within hours after IOP elevation and prior to axonal cytoskeletal rearrangement, producing some responses that recover rapidly and others that persist for days despite IOP normalization.
Collapse
Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| | - Lauren Davis
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - William O. Cepurna
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Tiffany E. Choe
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Diana C. Lozano
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Ashley Monfared
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Lauren Cooper
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Joshua Cheng
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Elaine C. Johnson
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - John C. Morrison
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, United States of America
| |
Collapse
|
32
|
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.
Collapse
|
33
|
Soysa NS, Alles N. Osteoclast function and bone-resorbing activity: An overview. Biochem Biophys Res Commun 2016; 476:115-20. [DOI: 10.1016/j.bbrc.2016.05.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/04/2016] [Indexed: 12/31/2022]
|
34
|
Rucci N, Teti A. The "love-hate" relationship between osteoclasts and bone matrix. Matrix Biol 2016; 52-54:176-190. [PMID: 26921625 DOI: 10.1016/j.matbio.2016.02.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/22/2016] [Accepted: 02/22/2016] [Indexed: 01/06/2023]
Abstract
Osteoclasts are unique cells that destroy the mineralized matrix of the skeleton. There is a "love-hate" relationship between the osteoclasts and the bone matrix, whereby the osteoclast is stimulated by the contact with the matrix but, at the same time, it disrupts the matrix, which, in turn, counteracts this disruption by some of its components. The balance between these concerted events brings about bone resorption to be controlled and to contribute to bone tissue integrity and skeletal health. The matrix components released by osteoclasts are also involved in the local regulation of other bone cells and in the systemic control of organismal homeostasis. Disruption of this regulatory loop causes bone diseases, which may end up with either reduced or increased bone mass, often associated with poor bone quality. Expanding the knowledge on osteoclast-to-matrix interaction could help to counteract these diseases and improve the human bone health. In this article, we will present evidence of the physical, molecular and regulatory relationships between the osteoclasts and the mineralized matrix, discussing the underlying mechanisms as well as their pathologic alterations and potential targeting.
Collapse
Affiliation(s)
- Nadia Rucci
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, Italy
| | - Anna Teti
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, Italy.
| |
Collapse
|
35
|
Choi SW, Yeon JT, Ryu BJ, Kim KJ, Moon SH, Lee H, Lee MS, Lee SY, Heo JC, Park SJ, Kim SH. Repositioning Potential of PAK4 to Osteoclastic Bone Resorption. J Bone Miner Res 2015; 30:1494-507. [PMID: 25640698 DOI: 10.1002/jbmr.2468] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 11/10/2022]
Abstract
Drug repositioning is a rational approach for expanding the use of existing drugs or candidate drugs to treat additional disorders. Here we investigated the possibility of using the anticancer p21-activated kinase 4 (PAK4)-targeted inhibitor PF-3758309 to treat osteoclast-mediated disorders. PAK4 was highly expressed in bone marrow cells and was phosphorylated during their differentiation into osteoclasts, and osteoclast differentiation was significantly inhibited by the dominant negative form of PAK4 and by PF-3758309. Specifically, PF-3758309 significantly inhibited the fusion of preosteoclasts, the podosome formation, and the migration of preosteoclasts. PF-3758309 also had in vivo antiresorptive activity in a lipopolysaccharide-induced bone erosion model and in vitro antiosteoclastogenic activity in the differentiation of human bone marrow-derived cells and peripheral blood mononuclear cells into osteoclasts. These data demonstrate the relevance of PAK4 in osteoclast differentiation and the potential of PAK4 inhibitors for treating osteoclast-related disorders.
Collapse
Affiliation(s)
- Sik-Won Choi
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Jeong-Tae Yeon
- Department of Pharmacy, Sunchon National University, Suncheon, South Korea
| | - Byung Jun Ryu
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Kwang-Jin Kim
- Department of Pharmacy, Sunchon National University, Suncheon, South Korea
| | - Seong-Hee Moon
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Hyuk Lee
- Medicinal Chemistry Research Center, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Myeung Su Lee
- Division of Rheumatology, Department of Internal Medicine, Wonkwang University, Iksan, Jeonbuk, South Korea
| | - Sam Youn Lee
- Department of Cardiac and Thoracic Surgery, Wonkwang University, Iksan, Jeonbuk, South Korea
| | - Jin-Chul Heo
- Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Sang-Joon Park
- Department of Histology, College of Veterinary Medicine, Kyungpook National University, Daegu, South Korea
| | - Seong Hwan Kim
- Laboratory of Translational Therapeutics, Pharmacology Research Center, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| |
Collapse
|
36
|
Wang L, Zhao K, Ren B, Zhu M, Zhang C, Zhao P, Zhou H, Chen L, Yu S, Yang X. Expression of cortactin in human gliomas and its effect on migration and invasion of glioma cells. Oncol Rep 2015; 34:1815-24. [PMID: 26238396 DOI: 10.3892/or.2015.4156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/25/2015] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to investigate the role of cortactin in the infiltrative behavior of glioma cells and the potential mechanism of cortactin in promoting the migration and invasion of glioma cells. The expression of cortactin was detected by immunohistochemistry in 40 human glioma specimens and 8 non-tumor brain specimens. U251, LN229 and SNB19 glioma cells were employed for the in vitro study and assigned into the siRNA-cortactin (transfected with siRNA specific to cortactin), siRNA-NC (transfected with negative control RNA sequence) and siRNA-N (transfected with empty vector) groups. The expression of cortactin in different treated glioma cell groups was detected using western blot analysis and RT-qPCR. The migration and invasion of glioma cells under different treatments were assessed using a wound-healing assay and Transwell-chamber invasion assay, respectively. The lamellipodia of glioma cells following treatment were observed by immunofluorescence (IF) and changes of lamellipodia over time were imaged using an inverted microscope. The distribution of cortactin and the actin-related protein 2/3 (Arp2/3) complex in glioma cells were observed after IF detection. The expression of cortactin in the glioma specimens was significantly higher than that in non-tumor brain tissue (P<0.05) and positively correlated with the malignancy of glioma specimens (r=0.912, P=0.00). The cortactin expression in glioma cells was markedly inhibited (P<0.05) and their migration and invasion ability was also impaired significantly following treatment with siRNA (P<0.05) compared with the other two groups. The size and persistence time of lamellipodia were reduced after cortactin expression was inhibited in glioma cells. Cortactin and the Arp2/3 complex were co-localized in the front of glioma cells, where actin was polymerized and lamellipodia formed. Thus, the results revealed that, cortactin is crucial in invasion and migration of glioma cells, which may promote the migration and invasion of glioma cells by regulating lamellipodia formation, a process requiring the combination of cortactin and the Arp2/3 complex.
Collapse
Affiliation(s)
- Leilei Wang
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Kai Zhao
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Bingcheng Ren
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Meng Zhu
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Chen Zhang
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Pengfei Zhao
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Hua Zhou
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Lei Chen
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Shenping Yu
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Xuejun Yang
- Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| |
Collapse
|
37
|
Fascin actin bundling controls podosome turnover and disassembly while cortactin is involved in podosome assembly by its SH3 domain in THP-1 macrophages and dendritic cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:940-52. [PMID: 25601713 DOI: 10.1016/j.bbamcr.2015.01.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/11/2014] [Accepted: 01/08/2015] [Indexed: 11/21/2022]
Abstract
Podosomes are dynamic degrading devices present in myeloid cells among other cell types. They consist of an actin core with associated regulators, surrounded by an adhesive ring. Both fascin and cortactin are known constituents but the role of fascin actin bundling is still unclear and cortactin research rather focuses on its homologue hematopoietic lineage cell-specific protein-1 (HS1). A fascin nanobody (FASNb5) that inhibits actin bundling and a cortactin nanobody (CORNb2) specifically targeting its Src-homology 3 (SH3) domain were used as unique tools to study the function of these regulators in podosome dynamics in both THP-1 macrophages and dendritic cells (DC). Upon intracellular FASNb5 expression, the few podosomes present were aberrantly stable, long-living and large, suggesting a role for fascin actin bundling in podosome turnover and disassembly. Fascin modulates this by balancing the equilibrium between branched and bundled actin networks. In the presence of CORNb2, the few podosomes formed show disrupted structures but their dynamics were unaffected. This suggests a role of the cortactin SH3 domain in podosome assembly. Remarkably, both nanobody-induced podosome-losses were compensated for by focal adhesion structures. Furthermore, matrix degradation capacities were altered and migratory phenotypes were lost. In conclusion, the cortactin SH3 domain contributes to podosome assembly while fascin actin bundling is a master regulator of podosome disassembly in THP-1 macrophages and DC.
Collapse
|
38
|
Kleinhans C, Schmid FF, Schmid FV, Kluger PJ. Comparison of osteoclastogenesis and resorption activity of human osteoclasts on tissue culture polystyrene and on natural extracellular bone matrix in 2D and 3D. J Biotechnol 2015; 205:101-10. [PMID: 25562421 DOI: 10.1016/j.jbiotec.2014.11.039] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/17/2014] [Accepted: 11/24/2014] [Indexed: 12/11/2022]
Abstract
Bone homeostasis is maintained by osteoblasts (bone formation) and osteoclasts (bone resorption). While there have been numerous studies investigating mesenchymal stem cells and their potential to differentiate into osteoblasts as well as their interaction with different bone substitute materials, there is only limited knowledge concerning in vitro generated osteoclasts. Due to the increasing development of degradable bone-grafting materials and the need of sophisticated in vitro test methods, it is essential to gain deeper insight into the process of osteoclastogenesis and the resorption functionality of human osteoclasts. Therefore, we focused on the comparison of osteoclastogenesis and resorption activity on tissue culture polystyrene (TCPS) and bovine extracellular bone matrices (BMs). Cortical bone slices were used as two-dimensional (2D) substrates, whereas a thermally treated cancellous bone matrix was used for three-dimensional (3D) experiments. We isolated primary human monocytes and induced osteoclastogenesis by medium supplementation. Subsequently, the expression of the vitronectin receptor (αVβ3) and cathepsin K as well as the characteristic actin formation on TCPS and the two BMs were examined. The cell area of human osteoclasts was analyzed on TCPS and on BMs, whereas significantly larger osteoclasts could be detected on BMs. Additionally, we compared the diameter of the sealing zones with the measured diameter of the resorption pits on the BMs and revealed similar diameters of the sealing zones and the resorption pits. We conclude that using TCPS as culture substrate does not affect the expression of osteoclast-specific markers. The analysis of resorption activity can successfully be conducted on cortical as well as on cancellous bone matrices. For new in vitro test systems concerning bone resorption, we suggest the establishment of a 2D assay for high throughput screening of new degradable bone substitute materials with osteoclasts.
Collapse
Affiliation(s)
- C Kleinhans
- Institute for Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart, Nobelstrasse 12, 70569 Stuttgart, Germany; Medical University Graz, Department of Orthopaedics, 8036 Graz, Austria
| | - F F Schmid
- Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) , Nobelstrasse 12, 70569 Stuttgart, Germany
| | - F V Schmid
- Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) , Nobelstrasse 12, 70569 Stuttgart, Germany
| | - P J Kluger
- Institute for Interfacial Process Engineering and Plasma Technology IGVP, University of Stuttgart, Nobelstrasse 12, 70569 Stuttgart, Germany; Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) , Nobelstrasse 12, 70569 Stuttgart, Germany; Reutlingen University, Process Analysis & Technology (PA&T), Alteburgstraße 150, 72762 Reutlingen, Germany.
| |
Collapse
|
39
|
Gov NS, Bernheim-Groswasser A. Releasing the brakes while hanging on: Cortactin effects on actin-driven motility. BIOARCHITECTURE 2014; 2:11-14. [PMID: 22754622 PMCID: PMC3383711 DOI: 10.4161/bioa.19739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Actin polymerization plays a major role in many cellular processes, including cell motility, vesicle trafficking, and pathogen propulsion. The transformation of the (protrusive) polymerization forces into directed motion requires that the growing filaments are positioned next to the surface. This is achieved by localization of surface actin nucleators (WASP), which then activate Arp2/3 complex to form new actin branches. Yet, the same surface-bound WASP molecule which initiates the nucleation of new actin branches, also inherently prevents the translation of the polymerization forces into motion, essentially because the WASP molecule has to be in contact with the network during the formation of the new branch. In our recent paper we show that cortactin relaxes this internal inhibition by enhancing the release of WASP-VCA molecule from the new branching site after nucleation is initiated. We show that this enhanced release has two major effects; it increases the turnover rate of branching per WASP molecule, and it decreases the friction-like force caused by the binding of the moving surface with respect to the growing actin network.
Collapse
|
40
|
Tehrani S, Johnson EC, Cepurna WO, Morrison JC. Astrocyte processes label for filamentous actin and reorient early within the optic nerve head in a rat glaucoma model. Invest Ophthalmol Vis Sci 2014; 55:6945-52. [PMID: 25257054 DOI: 10.1167/iovs.14-14969] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine if astrocyte processes label for actin and to quantify the orientation of astrocytic processes within the optic nerve head (ONH) in a rat glaucoma model. METHODS Chronic intraocular pressure (IOP) elevation was produced by episcleral hypertonic saline injection and tissues were collected after 5 weeks. For comparison, eyes with optic nerve transection were collected at 2 weeks. Fellow eyes served as controls. Axonal degeneration in retrobulbar optic nerves was graded on a scale of 1 to 5. Optic nerve head sections (n ≥ 4 eyes per group) were colabeled with phalloidin (actin marker) and antibodies to astrocytic glial fibrillary acidic protein and aquaporin 4, or axonal tubulin βIII. Confocal microscopy and FIJI software were used to quantify the orientation of actin bundles. RESULTS Control ONHs showed stereotypically arranged actin bundles within astrocyte processes. Optic nerve head actin bundle orientation was nearly perpendicular to axons (82.9° ± 6.3° relative to axonal axis), unlike the retrobulbar optic nerve (45.4° ± 28.7°, P < 0.05). With IOP elevation, ONH actin bundle orientation became less perpendicular to axons, even in eyes with no perceivable axonal injury (i.e., 38.8° ± 15.1° in grade 1, P < 0.05 in comparison to control ONHs). With severe injury, ONH actin bundle orientation became more parallel to the axonal axis (24.1° ± 28.4°, P < 0.05 in comparison to control ONHs). Optic nerve head actin bundle orientation in transected optic nerves was unchanged. CONCLUSIONS Actin labeling identifies fine astrocyte processes within the ONH. Optic nerve head astrocyte process reorientation occurs early in response to elevated IOP.
Collapse
Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Elaine C Johnson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - William O Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - John C Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| |
Collapse
|
41
|
Abstract
WIP plays an important role in the remodeling of the actin cytoskeleton, which controls cellular activation, proliferation, and function. WIP regulates actin polymerization by linking the actin machinery to signaling cascades. WIP binding to WASp and to its homolog, N-WASp, which are central activators of the actin-nucleating complex Arp2/3, regulates their cellular distribution, function, and stability. By binding to WASp, WIP protects it from degradation and thus, is crucial for WASp retention. Indeed, most mutations that result in WAS, an X-linked immunodeficiency caused by defective/absent WASp activity, are located in the WIP-binding region of WASp. In addition, by binding directly to actin, WIP promotes the formation and stabilization of actin filaments. WASp-independent activities of WIP constitute a new research frontier and are discussed extensively in this article. Here, we review the current information on WIP in human and mouse systems, focusing on its associated proteins, its molecular-regulatory mechanisms, and its role as a key regulator of actin-based processes in the immune system.
Collapse
Affiliation(s)
- Sophia Fried
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Omri Matalon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Elad Noy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Mira Barda-Saad
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| |
Collapse
|
42
|
Helgeson LA, Prendergast JG, Wagner AR, Rodnick-Smith M, Nolen BJ. Interactions with actin monomers, actin filaments, and Arp2/3 complex define the roles of WASP family proteins and cortactin in coordinately regulating branched actin networks. J Biol Chem 2014; 289:28856-69. [PMID: 25160634 DOI: 10.1074/jbc.m114.587527] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Arp2/3 complex is an important actin filament nucleator that creates branched actin filament networks required for formation of lamellipodia and endocytic actin structures. Cellular assembly of branched actin networks frequently requires multiple Arp2/3 complex activators, called nucleation promoting factors (NPFs). We recently presented a mechanism by which cortactin, a weak NPF, can displace a more potent NPF, N-WASP, from nascent branch junctions to synergistically accelerate nucleation. The distinct roles of these NPFs in branching nucleation are surprising given their similarities. We biochemically dissected these two classes of NPFs to determine how their Arp2/3 complex and actin interacting segments modulate their influences on branched actin networks. We find that the Arp2/3 complex-interacting N-terminal acidic sequence (NtA) of cortactin has structural features distinct from WASP acidic regions (A) that are required for synergy between the two NPFs. Our mutational analysis shows that differences between NtA and A do not explain the weak intrinsic NPF activity of cortactin, but instead that cortactin is a weak NPF because it cannot recruit actin monomers to Arp2/3 complex. We use TIRF microscopy to show that cortactin bundles branched actin filaments using actin filament binding repeats within a single cortactin molecule, but that N-WASP antagonizes cortactin-mediated bundling. Finally, we demonstrate that multiple WASP family proteins synergistically activate Arp2/3 complex and determine the biochemical requirements in WASP proteins for synergy. Our data indicate that synergy between WASP proteins and cortactin may play a general role in assembling diverse actin-based structures, including lamellipodia, podosomes, and endocytic actin networks.
Collapse
Affiliation(s)
- Luke A Helgeson
- From the Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1229
| | - Julianna G Prendergast
- From the Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1229
| | - Andrew R Wagner
- From the Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1229
| | - Max Rodnick-Smith
- From the Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1229
| | - Brad J Nolen
- From the Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1229
| |
Collapse
|
43
|
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: 44] [Impact Index Per Article: 4.0] [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.
Collapse
|
44
|
Feng S, Zhu G, McConnell M, Deng L, Zhao Q, Wu M, Zhou Q, Wang J, Qi J, Li YP, Chen W. Silencing of atp6v1c1 prevents breast cancer growth and bone metastasis. Int J Biol Sci 2013; 9:853-62. [PMID: 24155661 PMCID: PMC3805834 DOI: 10.7150/ijbs.6030] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 08/07/2013] [Indexed: 12/30/2022] Open
Abstract
Previous studies have shown that Atp6v1c1, a regulator of the assembly of the V0 and V1 domains of the V-ATPase complex, is up-regulated in metastatic oral tumors. Despite these studies, the function of Atp6v1c1 in tumor growth and metastasis is still unknown. Atp6v1c1's expression in metastatic oral squamous cell carcinoma indicates that Atp6v1c1 has an important function in cancer growth and metastasis. We hypothesized that elevated expression of Atp6v1c1 is essential to cancer growth and metastasis and that Atp6v1c1 promotes cancer growth and metastasis through activation of V-ATPase activity. To test this hypothesis, a Lentivirus-mediated RNAi knockdown approach was used to study the function of Atp6v1c1 in mouse 4T1 mammary tumor cell proliferation and migration in vitro and cancer growth and metastasis in vivo. Our data revealed that silencing of Atp6v1c1 in 4T1 cancer cells inhibited lysosomal acidification and severely impaired 4T1 cell growth, migration, and invasion through Matrigel in vitro. We also show that Atp6v1c1 knockdown with Lenti-c1s3, a lentivirus targeting Atp6v1c1 for shRNA mediated knockdown, can significantly inhibit 4T1 xenograft tumor growth, metastasis, and osteolytic lesions in vivo. Our study demonstrates that Atp6v1c1 may promote breast cancer growth and bone metastasis through regulation of lysosomal V-ATPase activity, indicating that Atp6v1c1 may be a viable target for breast cancer therapy and silencing of Atp6v1c1 may be an innovative therapeutic approach for the treatment and prevention of breast cancer growth and metastasis.
Collapse
Affiliation(s)
- Shengmei Feng
- 1. Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, P.R.China. ; 2. Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, U.S.A
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Oikawa T, Kuroda Y, Matsuo K. Regulation of osteoclasts by membrane-derived lipid mediators. Cell Mol Life Sci 2013; 70:3341-53. [PMID: 23296124 PMCID: PMC3753467 DOI: 10.1007/s00018-012-1238-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/05/2012] [Accepted: 12/10/2012] [Indexed: 12/22/2022]
Abstract
Osteoclasts are bone-resorbing cells of monocytic origin. An imbalance between bone formation and resorption can lead to osteoporosis or osteopetrosis. Osteoclastogenesis is triggered by RANKL- and IP3-induced Ca2+ influx followed by activation of NFATc1, a master transcription factor for osteoclastogenic gene regulation. During differentiation, osteoclasts undergo cytoskeletal remodeling to migrate and attach to the bone surface. Simultaneously, they fuse with each other to form multinucleated cells. These processes require PI3-kinase-dependent cytoskeletal protein activation to initiate cytoskeletal remodeling, resulting in the formation of circumferential podosomes and fusion-competent protrusions. In multinucleated osteoclasts, circumferential podosomes mature into stabilized actin rings, which enables the formation of a ruffled border where intensive membrane trafficking is executed. Membrane lipids, especially phosphoinositides, are key signaling molecules that regulate osteoclast morphology and act as second messengers and docking sites for multiple important effectors. We examine the critical roles of phosphoinositides in the signaling cascades that regulate osteoclast functions.
Collapse
Affiliation(s)
- Tsukasa Oikawa
- Laboratory of Cell and Tissue Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | | | | |
Collapse
|
46
|
Vogl AW, Young JS, Du M. New insights into roles of tubulobulbar complexes in sperm release and turnover of blood-testis barrier. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 303:319-55. [PMID: 23445814 DOI: 10.1016/b978-0-12-407697-6.00008-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tubulobulbar complexes are actin-filament-related structures that form at intercellular junctions in the seminiferous epithelium of mammalian testis. The structures occur both at adhesion junctions between Sertoli cells and the maturing spermatids in apical regions of the epithelium, and at junction complexes between neighboring Sertoli cells near the base of the epithelium. Here, we review the general morphology and molecular composition of tubulobulbar complexes, and also include a description of tubulobulbar complex structure in the human seminiferous epithelium. Although tubulobulbar complexes are unique to the seminiferous epithelium, they have the molecular signature of clathrin-based endocytosis machinery present generally in cells. We review the evidence that tubulobulbar complexes internalize intact intercellular junctions and are significant components of the sperm-release mechanism and the process by which spermatocytes translocate from basal to adluminal compartments of the epithelium.
Collapse
Affiliation(s)
- A Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada.
| | | | | |
Collapse
|
47
|
Pan YR, Tseng WS, Chang PW, Chen HC. Phosphorylation of moesin by c-Jun N-terminal kinase is important for podosome rosette formation in Src-transformed fibroblasts. J Cell Sci 2013; 126:5670-80. [DOI: 10.1242/jcs.134361] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Podosomes are actin-based membrane protrusions that facilitate extracellular matrix degradation and invasive cell motility. Podosomes can self-organize into large rosette-like structures in Src-transformed fibroblasts, osteoclasts, and some highly invasive cancer cells. However, the mechanism of this assembly remains obscure. In this study, we show that the suppression of c-Jun N-terminal kinase (JNK) by the JNK inhibitor SP600125 or short-hairpin RNA inhibited podosome rosette formation in SrcY527F-transformed NIH3T3 fibroblasts. In addition, SrcY527F was less potent to induce podosome rosettes in JNK1-null or JNK2-null mouse embryo fibroblasts than in their wild-type counterparts. The kinase activity of JNK was essential for promoting podosome rosette formation but not for its localization to podosome rosettes. Moesin, a member of the ERM (ezrin, radixin, and moesin) protein family, was identified as a substrate of JNK. We show that the phosphorylation of moesin at Thr558 by JNK was important for podosome rosette formation in SrcY527F-transformed NIH3T3 fibroblasts. Taken together, our results unveil a novel role of JNK in podosome rosette formation by phosphorylating moesin.
Collapse
|
48
|
Menon M, Schafer DA. Dynamin: expanding its scope to the cytoskeleton. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 302:187-219. [PMID: 23351711 DOI: 10.1016/b978-0-12-407699-0.00003-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The large GTPase dynamin is well known for its actions on budded cellular membranes to generate vesicles, most often, clathrin-coated endocytic vesicles. The scope of cellular processes in which dynamin-mediated vesicle formation occurs, has expanded to include secretory vesicle formation at the Golgi, from other endosomes and nonclathrin structures, such as caveolae, as well as membrane remodeling during exocytosis and vesicle fusion. An intriguing new facet of dynamin's sphere of influence is the cytoskeleton. Cytoskeletal filament networks maintain cell shape, provide cell movement, execute cell division and orchestrate vesicle trafficking. Recent evidence supports the hypothesis that dynamin influences actin filaments and microtubules via mechanisms that are independent of its membrane-remodeling activities. This chapter discusses this emerging evidence and considers possible mechanisms of action.
Collapse
Affiliation(s)
- Manisha Menon
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | | |
Collapse
|
49
|
Abstract
Many forms of cellular motility are driven by the growth of branched networks of actin filaments, which push against a membrane. In the dendritic nucleation model, Arp2/3 complex is critical, binding to the side of an existing mother filament, nucleating a new daughter filament, and thus creating a branch. Spatial and temporal regulation of Arp2/3 activity is critical for efficient generation of force and movement. A diverse collection of Arp2/3 regulatory proteins has been identified. They bind to and/or activate Arp2/3 complex via an acidic motif with a conserved tryptophan residue. We tested this model for Arp2/3 regulator function in vivo, by examining the roles of multiple Arp2/3 regulators in endocytosis in living yeast cells. We measured the molecular composition of the actin network in cells with mutations that removed the acidic motifs of the four Arp2/3 regulators previously shown to influence the proper function of the actin network. Unexpectedly, we did not find a simple or direct correlation between defects in patch assembly and movement and changes in the composition and dynamics of dendritic nucleation proteins. Taken together our data does not support the simple hypothesis that the primary role for Arp2/3 regulators is to recruit and activate Arp2/3. Rather our data suggests that these regulators may be playing more subtle roles in establishing functional networks in vivo.
Collapse
Affiliation(s)
- Brian J Galletta
- Department of Cell Biology and Physiology, Washington University, Saint Louis, MO, USA
| | | | | |
Collapse
|
50
|
Cervero P, Himmel M, Krüger M, Linder S. Proteomic analysis of podosome fractions from macrophages reveals similarities to spreading initiation centres. Eur J Cell Biol 2012; 91:908-22. [DOI: 10.1016/j.ejcb.2012.05.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 05/10/2012] [Accepted: 05/11/2012] [Indexed: 12/24/2022] Open
|