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Almutairi F, Sarr D, Tucker SL, Fantone K, Lee JK, Rada B. RGS10 Reduces Lethal Influenza Infection and Associated Lung Inflammation in Mice. Front Immunol 2021; 12:772288. [PMID: 34912341 PMCID: PMC8667315 DOI: 10.3389/fimmu.2021.772288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/10/2021] [Indexed: 01/05/2023] Open
Abstract
Seasonal influenza epidemics represent a significant global health threat. The exacerbated immune response triggered by respiratory influenza virus infection causes severe pulmonary damage and contributes to substantial morbidity and mortality. Regulator of G-protein signaling 10 (RGS10) belongs to the RGS protein family that act as GTPase activating proteins for heterotrimeric G proteins to terminate signaling pathways downstream of G protein-coupled receptors. While RGS10 is highly expressed in immune cells, in particular monocytes and macrophages, where it has strong anti-inflammatory effects, its physiological role in the respiratory immune system has not been explored yet. Here, we show that Rgs10 negatively modulates lung immune and inflammatory responses associated with severe influenza H1N1 virus respiratory infection in a mouse model. In response to influenza A virus challenge, mice lacking RGS10 experience enhanced weight loss and lung viral titers, higher mortality and significantly faster disease onset. Deficiency of Rgs10 upregulates the levels of several proinflammatory cytokines and chemokines and increases myeloid leukocyte accumulation in the infected lung, markedly neutrophils, monocytes, and inflammatory monocytes, which is associated with more pronounced lung damage. Consistent with this, influenza-infected Rgs10-deficent lungs contain more neutrophil extracellular traps and exhibit higher neutrophil elastase activities than wild-type lungs. Overall, these findings propose a novel, in vivo role for RGS10 in the respiratory immune system controlling myeloid leukocyte infiltration, viral clearance and associated clinical symptoms following lethal influenza challenge. RGS10 also holds promise as a new, potential therapeutic target for respiratory infections.
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Affiliation(s)
- Faris Almutairi
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, United States
| | - Demba Sarr
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Samantha L. Tucker
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Kayla Fantone
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Jae-Kyung Lee
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Balázs Rada
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
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Qu G, He T, Dai A, Zhao Y, Guan D, Li S, Shi H, Gan W, Zhang A. miR-199b-5p mediates adriamycin-induced podocyte apoptosis by inhibiting the expression of RGS10. Exp Ther Med 2021; 22:1469. [PMID: 34737809 PMCID: PMC8561778 DOI: 10.3892/etm.2021.10904] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/01/2021] [Indexed: 11/06/2022] Open
Abstract
Podocyte apoptosis is a key risk factor for the progression of kidney diseases. MicroRNA (miR)-199b-5p has been shown to be involved in cell apoptosis. However, the molecular mechanisms of miR-199b-5p in podocyte apoptosis remain uncertain. Thus, the present study aimed to investigate whether miR-199b-5p participates in the regulation of podocyte apoptosis and to elucidate the involved mechanisms of this process. A podocyte apoptosis model was constructed using adriamycin (ADR) in vitro. miR-199b-5p mimic and inhibitor were transfected in podocytes to change the expression level of miR-199b-5p. RNA expression was examined by reverse transcription-quantitative PCR. Western blotting was used to measure protein expression. Apoptosis was monitored via flow cytometry and detection of apoptosis-associated proteins. The results from the present study demonstrated that miR-199b-5p was upregulated and that regulator of G-protein signaling 10 (RGS10) was downregulated in ADR-stimulated podocytes. Overexpression of miR-199b-5p could inhibit RGS10 expression and stimulate podocyte apoptosis, whereas miR-199b-5p knockdown restored the levels of RGS10 and ameliorated podocyte apoptosis in ADR-induced podocytes. Furthermore, the effects of miR-199b-5p overexpression could be significantly reversed by RGS10 overexpression. In addition, podocyte transfection of miR-199b-5p activated the AKT/mechanistic target of rapamycin (mTOR) signaling, which was blocked following RGS10 overexpression. Taken together, the present study demonstrated that miR-199b-5p upregulation could promote podocyte apoptosis by inhibiting the expression of RGS10 through the activation of AKT/mTOR signaling.
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Affiliation(s)
- Gaoting Qu
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
| | - Tiantian He
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
| | - Aisuo Dai
- Department of Pediatrics, Taizhou People's Hospital, Taizhou, Jiangsu 225300, P.R. China
| | - Yajie Zhao
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
| | - Dian Guan
- Department of Pediatric Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Shanwen Li
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
| | - Huimin Shi
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
| | - Weihua Gan
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
| | - Aiqing Zhang
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003, P.R. China
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Yang H, Song L, Sun B, Chu D, Yang L, Li M, Li H, Dai Y, Yu Z, Guo J. Modulation of macrophages by a paeoniflorin-loaded hyaluronic acid-based hydrogel promotes diabetic wound healing. Mater Today Bio 2021; 12:100139. [PMID: 34632363 PMCID: PMC8488309 DOI: 10.1016/j.mtbio.2021.100139] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/28/2021] [Accepted: 09/05/2021] [Indexed: 02/05/2023] Open
Abstract
The impaired wound healing in diabetes is a central concern of healthcare worldwide. However, current treatments often fail due to the complexity of diabetic wounds, and thus, emerging therapeutic approaches are needed. Macrophages, a prominent immune cell in the wound, play key roles in tissue repair and regeneration. Recent evidence has demonstrated that macrophages in diabetic wounds maintain a persistent proinflammatory phenotype that causes the failure of healing. Therefore, modulation of macrophages provides great promise for wound healing in diabetic patients. In this study, the potential of paeoniflorin (PF, a chemical compound derived from the herb Paeonia lactiflora) for the transition of macrophages from M1 (proinflammatory phenotype) to M2 (anti-inflammatory/prohealing phenotype) was confirmed using ex vivo and in vivo experimental approaches. A hydrogel based on high molecular weight hyaluronic acid (HA) was developed for local administration of PF in experimental diabetic mice with a full-thickness wound. The resultant formulation (HA-PF) was able to significantly promote cutaneous healing as compared to INTRASITE Gel (a commercial hydrogel wound dressing). This outcome was accompanied by the amelioration of inflammation, the improvement of angiogenesis, and re-epithelialization, and the deposition of collagen. Our study indicates the significant potential of HA-PF for clinical translation in diabetic wound healing.
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Key Words
- Adipic acid dihydrazide, ADH
- Angiogenesis
- Anti-inflammation
- Hydrogel
- Macrophage polarization
- N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, EDC.HCl
- Regenerative medicine
- arginase 1, Arg-1
- bone marrow-derived macrophages, BMDMs
- dimethyl sulfoxide, DMSO
- fetal bovine serum, FBS
- human umbilical vein endothelial cells, HUVECs
- hyaluronic acid, HA
- inducible nitric oxide synthase, iNOS
- integrated optical density, IOD
- interferon-γ, IFN-γ
- interleukin-10, IL-10
- interleukin-1β, IL-1β
- lipopolysaccharide, LPS
- macrophage colony-stimulating factor, M-CSF
- paeoniflorin, PF
- penicillin-streptomycin, P/S
- phosphate-buffered saline, PBS
- polyvinylidene difluoride, PVDF
- scanning electron microscopy, SEM
- signal transducer and activator of transcription, STAT
- streptozocin, STZ
- swelling ratio, SR
- transforming growth factor-β, TGF-β
- tumor necrosis factor-α, TNF-α
- α-smooth muscle actin, α-SMA
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Affiliation(s)
- Hao Yang
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Liu Song
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Bingxue Sun
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Di Chu
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Leilei Yang
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Meng Li
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Huan Li
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Yun Dai
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, 130021, China
| | - Zhuo Yu
- Department of Hepatopathy, Shuguang Hospital, Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Jianfeng Guo
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
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Almutairi F, Tucker SL, Sarr D, Rada B. PI3K/ NF-κB-dependent TNF-α and HDAC activities facilitate LPS-induced RGS10 suppression in pulmonary macrophages. Cell Signal 2021; 86:110099. [PMID: 34339853 PMCID: PMC8406451 DOI: 10.1016/j.cellsig.2021.110099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/16/2022]
Abstract
Regulator of G-protein signaling 10 (RGS10) is a member of the superfamily of RGS proteins that canonically act as GTPase activating proteins (GAPs). RGS proteins accelerate GTP hydrolysis on the G-protein α subunits and result in termination of signaling pathways downstream of G protein-coupled receptors. Beyond its GAP function, RGS10 has emerged as an anti-inflammatory protein by inhibiting LPS-mediated NF-κB activation and expression of inflammatory cytokines, in particular TNF-α. Although RGS10 is abundantly expressed in resting macrophages, previous studies have shown that RGS10 expression is suppressed in macrophages following Toll-like receptor 4 (TLR4) activation by LPS. However, the molecular mechanism by which LPS induces Rgs10 silencing has not been clearly defined. The goal of the current study was to determine whether LPS silences Rgs10 expression through an NF-κB-mediated proinflammatory mechanism in pulmonary macrophages, a unique type of innate immune cells. We demonstrate that Rgs10 transcript and RGS10 protein levels are suppressed upon LPS treatment in the murine MH-S alveolar macrophage cell line. We show that pharmacological inhibition of PI3K/ NF-κB/p300 (NF-κB co-activator)/TNF-α signaling cascade and the activities of HDAC (1-3) enzymes block LPS-induced silencing of Rgs10 in MH-S cells as well as microglial BV2 cells and BMDMs. Further, loss of RGS10 generated by using CRISPR/Cas9 amplifies NF-κB phosphorylation and inflammatory gene expression following LPS treatment in MH-S cells. Together, our findings strongly provide critical insight into the molecular mechanism underlying RGS10 suppression by LPS in pulmonary macrophages.
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Affiliation(s)
- Faris Almutairi
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA; Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Samantha L Tucker
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Demba Sarr
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Balázs Rada
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
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Almutairi F, Lee JK, Rada B. Regulator of G protein signaling 10: Structure, expression and functions in cellular physiology and diseases. Cell Signal 2020; 75:109765. [PMID: 32882407 PMCID: PMC7579743 DOI: 10.1016/j.cellsig.2020.109765] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 01/22/2023]
Abstract
Regulator of G protein signaling 10 (RGS10) belongs to the superfamily of RGS proteins, defined by the presence of a conserved RGS domain that canonically binds and deactivates heterotrimeric G-proteins. RGS proteins act as GTPase activating proteins (GAPs), which accelerate GTP hydrolysis on the G-protein α subunits and result in termination of signaling pathways downstream of G protein-coupled receptors. RGS10 is the smallest protein of the D/R12 subfamily and selectively interacts with Gαi proteins. It is widely expressed in many cells and tissues, with the highest expression found in the brain and immune cells. RGS10 expression is transcriptionally regulated via epigenetic mechanisms. Although RGS10 lacks multiple of the defined regulatory domains found in other RGS proteins, RGS10 contains post-translational modification sites regulating its expression, localization, and function. Additionally, RGS10 is a critical protein in the regulation of physiological processes in multiple cells, where dysregulation of its expression has been implicated in various diseases including Parkinson's disease, multiple sclerosis, osteopetrosis, chemoresistant ovarian cancer and cardiac hypertrophy. This review summarizes RGS10 features and its regulatory mechanisms, and discusses the known functions of RGS10 in cellular physiology and pathogenesis of several diseases.
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Affiliation(s)
- Faris Almutairi
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, USA; Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Jae-Kyung Lee
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Balázs Rada
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
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Alqinyah M, Almutairi F, Wendimu MY, Hooks SB. RGS10 Regulates the Expression of Cyclooxygenase-2 and Tumor Necrosis Factor Alpha through a G Protein-Independent Mechanism. Mol Pharmacol 2018; 94:1103-1113. [PMID: 30049816 DOI: 10.1124/mol.118.111674] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 07/11/2018] [Indexed: 01/18/2023] Open
Abstract
The small regulator of G protein signaling protein RGS10 is a key regulator of neuroinflammation and ovarian cancer cell survival; however, the mechanism for RGS10 function in these cells is unknown and has not been linked to specific G protein pathways. RGS10 is highly enriched in microglia, and loss of RGS10 expression in microglia amplifies production of the inflammatory cytokine tumor necrosis factor α (TNFα) and enhances microglia-induced neurotoxicity. RGS10 also regulates cell survival and chemoresistance of ovarian cancer cells. Cyclooxygenase-2 (COX-2)-mediated production of prostaglandins such as prostaglandin E2 (PGE2) is a key factor in both neuroinflammation and cancer chemoresistance, suggesting it may be involved in RGS10 function in both cell types, but a connection between RGS10 and COX-2 has not been reported. To address these questions, we completed a mechanistic study to characterize RGS10 regulation of TNFα and COX-2 and to determine if these effects are mediated through a G protein-dependent mechanism. Our data show for the first time that loss of RGS10 expression significantly elevates stimulated COX-2 expression and PGE2 production in microglia. Furthermore, the elevated inflammatory signaling resulting from RGS10 loss was not affected by Gαi inhibition, and a RGS10 mutant that is unable to bind activated G proteins was as effective as wild type in inhibiting TNFα expression. Similarly, suppression of RGS10 in ovarian cancer cells enhanced TNFα and COX-2 expression, and this effect did not require Gi activity. Together, our data strongly indicate that RGS10 inhibits COX-2 expression by a G protein-independent mechanism to regulate inflammatory signaling in microglia and ovarian cancer cells.
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Affiliation(s)
- Mohammed Alqinyah
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Faris Almutairi
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Menbere Y Wendimu
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
| | - Shelley B Hooks
- Hooks Laboratory, Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia
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McConnell M, Feng S, Chen W, Zhu G, Shen D, Ponnazhagan S, Deng L, Li YP. Osteoclast proton pump regulator Atp6v1c1 enhances breast cancer growth by activating the mTORC1 pathway and bone metastasis by increasing V-ATPase activity. Oncotarget 2018; 8:47675-47690. [PMID: 28504970 PMCID: PMC5564597 DOI: 10.18632/oncotarget.17544] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/15/2016] [Indexed: 02/06/2023] Open
Abstract
It is known that V-ATPases (vacuolar H+-ATPase) are involved in breast cancer growth and metastasis. Part of this action is similar to their role in osteoclasts, where they’re involved in extracellular acidification and matrix destruction; however, the roles of their subunits in cancer cell proliferation, signaling, and other pro-tumor actions are not well established. Analysis of TCGA data shows that V-ATPase subunit Atp6v1c1 is overexpressed or amplified in 34% of human breast cancer cases, with a 2-fold decrease in survival at 12 years. Whereas other subunits, such as Atp6v1c2 and Atp6v0a3, are overexpressed or genomically amplified less often, 6% each respectively, and have less impact on survival. Experiments show that lentiviral-shRNA mediated ATP6v1c1 knockdown in 4T1 mouse mammary cancer cells significantly reduces orthotopic and intraosseous tumor growth. ATP6v1c1 knockdown also significantly reduces tumor stimulated bone resorption through osteoclastogenesis at the bone and metastasis in vivo, as well as V-ATPase activity, proliferation, and mTORC1 activation in vitro. To generalize the effects of ATP6v1c1 knockdown on proliferation and mTORC1 activation we used human cancer cell lines - MCF-7, MDA-MB-231, and MDA-MB-435s. ATP6V1C1 knockdown reduced cell proliferation and impaired mTORC1 pathway activation in cancer cells but not in the untransformed cell line C3H10T1/2. Our study reveals that V-ATPase activity may be mediated through mTORC1 and that ATP6v1c1 can be knocked down to block both V-ATPase and mTORC1 activity.
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Affiliation(s)
- Matthew McConnell
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shengmei Feng
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Shanghai Institute of Traumatology and Orthopedics, 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
| | - Wei Chen
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Guochun Zhu
- Shanghai Institute of Traumatology and Orthopedics, 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
| | - Dejun Shen
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Lianfu Deng
- Shanghai Institute of Traumatology and Orthopedics, 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
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
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Intini G, Katsuragi Y, Kirkwood KL, Yang S. Alveolar bone loss: mechanisms, potential therapeutic targets, and interventions. Adv Dent Res 2016; 26:38-46. [PMID: 24736703 DOI: 10.1177/0022034514529305] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This article reviews recent research into mechanisms underlying bone resorption and highlights avenues of investigation that may generate new therapies to combat alveolar bone loss in periodontitis. Several proteins, signaling pathways, stem cells, and dietary supplements are discussed as they relate to periodontal bone loss and regeneration. RGS12 is a crucial protein that mediates osteoclastogenesis and bone destruction, and a potential therapeutic target. RGS12 likely regulates osteoclast differentiation through regulating calcium influx to control the calcium oscillation-NFATc1 pathway. A working model for RGS10 and RGS12 in the regulation of Ca(2+) oscillations during osteoclast differentiation is proposed. Initiation of inflammation depends on host cell-microbe interactions, including the p38 mitogen-activated protein kinase (MAPK) signaling pathway. Oral p38 inhibitors reduced lipopolysaccharide (LPS)-induced bone destruction in a rat periodontitis model but showed unsatisfactory safety profiles. The p38 substrate MK2 is a more specific therapeutic target with potentially superior tolerability. Furthermore, MKP-1 shows anti-inflammatory activity, reducing inflammatory cytokine biosynthesis and bone resorption. Multipotent skeletal stem cell (SSC) populations exist within the bone marrow and periosteum of long bones. These bone-marrow-derived SSCs and periosteum-derived SSCs have shown therapeutic potential in several applications, including bone and periodontal regeneration. The existence of craniofacial bone-specific SSCs is suggested based on existing studies. The effects of calcium, vitamin D, and soy isoflavone supplementation on alveolar and skeletal bone loss in post-menopausal women were investigated. Supplementation resulted in stabilization of forearm bone mass density and a reduced rate of alveolar bone loss over 1 yr, compared with placebo. Periodontal attachment levels were also well-maintained and alveolar bone loss suppressed during 24 wk of supplementation.
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Affiliation(s)
- G Intini
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, 188 Longwood Avenue, REB 513, Boston, MA 02115, USA
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Miao R, Lu Y, Xing X, Li Y, Huang Z, Zhong H, Huang Y, Chen AF, Tang X, Li H, Cai J, Yuan H. Regulator of G-Protein Signaling 10 Negatively Regulates Cardiac Remodeling by Blocking Mitogen-Activated Protein Kinase–Extracellular Signal-Regulated Protein Kinase 1/2 Signaling. Hypertension 2016; 67:86-98. [PMID: 26573707 DOI: 10.1161/hypertensionaha.115.05957] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/28/2015] [Indexed: 11/16/2022]
Abstract
Regulator of G-protein signaling 10 (RGS10) is an important member of the RGS family and produces biological effects in multiple organs. We used a genetic approach to study the role of RGS10 in the regulation of pathological cardiac hypertrophy and found that RGS10 can negatively influence pressure overload–induced cardiac remodeling. RGS10 expression was markedly decreased in failing human hearts and hypertrophic murine hearts. The extent of aortic banding–induced cardiac hypertrophy, dysfunction, and fibrosis in RGS10-knockout mice was exacerbated, whereas the heart of transgenic mice with cardiac-specific RGS10 overexpression exhibited an alleviated response to pressure overload. Consistently, RGS10 also inhibited an angiotensin II–induced hypertrophic response in isolated cardiomyocytes. Mechanistically, cardiac remodeling improvement elicited by RGS10 was associated with the abrogation of mitogen-activated protein kinase kinase 1/2–extracellular signal-regulated protein kinase 1/2 signaling. Furthermore, the inhibition of mitogen-activated protein kinase kinase–extracellular signal-regulated protein kinase 1/2 transduction abolished RGS10 deletion-induced hypertrophic aggravation. These findings place RGS10 and its downstream signaling mitogen-activated protein kinase kinase–extracellular signal-regulated protein kinase 1/2 as crucial regulators of pathological cardiac hypertrophy after pressure overload and identify this pathway as a potential therapeutic target to attenuate the pressure overload–driven cardiac remodeling.
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Affiliation(s)
- Rujia Miao
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Yao Lu
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Xiaowei Xing
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Ying Li
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Zhijun Huang
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Hua Zhong
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Yun Huang
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Alex F. Chen
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Xiaohong Tang
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Hongliang Li
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Jingjing Cai
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
| | - Hong Yuan
- From the Department of Cardiology (R.M., H.Z., A.F.C., X.T., J.C., H.Y.) and Center of Clinical Pharmacology (Y.L., X.X., Y.L., Z.H., Y.H., J.C., H.Y.), the Third Xiangya Hospital, Central South University, Changsha, China; Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China (H.L.); and Cardiovascular Research Institute of Wuhan University, Wuhan, China (H.L.)
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10
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Chen Z, Su L, Xu Q, Katz J, Michalek SM, Fan M, Feng X, Zhang P. IL-1R/TLR2 through MyD88 Divergently Modulates Osteoclastogenesis through Regulation of Nuclear Factor of Activated T Cells c1 (NFATc1) and B Lymphocyte-induced Maturation Protein-1 (Blimp1). J Biol Chem 2015; 290:30163-74. [PMID: 26483549 DOI: 10.1074/jbc.m115.663518] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Indexed: 01/10/2023] Open
Abstract
Toll-like receptors (TLR) and the receptor for interleukin-1 (IL-1R) signaling play an important role in bacteria-mediated bone loss diseases including periodontitis, rheumatoid arthritis, and osteomyelitis. Recent studies have shown that TLR ligands inhibit the receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation from un-committed osteoclast precursors, whereas IL-1 potentiates RANKL-induced osteoclast formation. However, IL-1R and TLR belong to the same IL-1R/TLR superfamily, and activate similar intracellular signaling pathways. Here, we investigate the molecular mechanisms underlying the distinct effects of IL-1 and Porphyromonas gingivalis lipopolysaccharide (LPS-PG) on RANKL-induced osteoclast formation. Our results show that LPS-PG and IL-1 differentially regulate RANKL-induced activation of osteoclast genes encoding Car2, Ctsk, MMP9, and TRAP, as well as expression of NFATc1, a master transcription factor of osteoclastogenesis. Regulation of osteoclast genes and NFATc1 by LPS-PG and IL-1 is dependent on MyD88, an important signaling adaptor for both TLR and IL-1R family members. Furthermore, LPS-PG and IL-1 differentially regulate RANKL-costimulatory receptor OSCAR (osteoclast-associated receptor) expression and Ca(2+) oscillations induced by RANKL. Moreover, LPS-PG completely abrogates RANKL-induced gene expression of B lymphocyte-induced maturation protein-1 (Blimp1), a global transcriptional repressor of anti-osteoclastogenic genes encoding Bcl6, IRF8, and MafB. However, IL-1 enhances RANKL-induced blimp1 gene expression but suppresses the gene expression of bcl6, irf8, and mafb. Our study reveals the involvement of multiple signaling molecules in the differential regulation of RANKL-induced osteoclastogenesis by TLR2 and IL-1 signaling. Understanding the signaling cross-talk among TLR, IL-1R, and RANK is critical for identifying therapeutic strategies to control bacteria-mediated bone loss.
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Affiliation(s)
- Zhihong Chen
- From the Departments of Pediatric Dentistry, the Department of Prosthodontics, School and Hospital of Stomatology, Zhejiang University, Hangzhou, Zhejiang 310006, China, and
| | - Lingkai Su
- From the Departments of Pediatric Dentistry
| | - Qingan Xu
- From the Departments of Pediatric Dentistry, the The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China
| | - Jenny Katz
- From the Departments of Pediatric Dentistry
| | | | - Mingwen Fan
- the The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China
| | - Xu Feng
- Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Ping Zhang
- From the Departments of Pediatric Dentistry,
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11
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Cellular deficiency in the RGS10 protein facilitates chemoresistant ovarian cancer. Future Med Chem 2015; 7:1483-9. [PMID: 26293348 DOI: 10.4155/fmc.15.81] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
More than 30 regulators of G protein signaling (RGS) proteins encompass the RGS protein superfamily of critical regulators essential to cellular homeostasis. There is enormous structural and functional diversity among the RGS superfamily, and as such they serve a wide range of functions in regulating cell biology and physiology. Recent evidence has suggested roles for multiple RGS proteins in cancer initiation and progression, which has prompted research toward the potential modulation of these proteins as a new approach in cancer therapy. This article will discuss basic RGS molecular pharmacology, summarize the cellular functions and epigenetic regulation of RGS10, review ovarian cancer chemotherapy and describe the role of RGS10 in ovarian cancer survival signaling.
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12
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Li S, Hao L, Wang L, Lu Y, Li Q, Zhu Z, Shao JZ, Chen W. Targeting Atp6v1c1 Prevents Inflammation and Bone Erosion Caused by Periodontitis and Reveals Its Critical Function in Osteoimmunology. PLoS One 2015; 10:e0134903. [PMID: 26274612 PMCID: PMC4537256 DOI: 10.1371/journal.pone.0134903] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 07/16/2015] [Indexed: 01/08/2023] Open
Abstract
Periodontal disease (Periodontitis) is a serious disease that affects a majority of adult Americans and is associated with other systemic diseases, including diabetes, rheumatoid arthritis, and other inflammatory diseases. While great efforts have been devoted toward understanding the pathogenesis of periodontitis, there remains a pressing need for developing potent therapeutic strategies for targeting this pervasive and destructive disease. In this study, we utilized novel adeno-associated virus (AAV)-mediated Atp6v1c1 knockdown gene therapy to treat bone erosion and inflammatory caused by periodontitis in mouse model. Atp6v1c1 is a subunit of the V-ATPase complex and regulator of the assembly of the V0 and V1 domains of the V-ATPase complex. We demonstrated previously that Atp6v1c1 has an essential function in osteoclast mediated bone resorption. We hypothesized that Atp6v1c1 may be an ideal target to prevent the bone erosion and inflammation caused by periodontitis. To test the hypothesis, we employed AAV RNAi knockdown of Atp6v1c1 gene expression to prevent bone erosion and gingival inflammation simultaneously. We found that lesion-specific injection of AAV-shRNA-Atp6v1c1 into the periodontal disease lesions protected against bone erosion (>85%) and gingival inflammation caused by P. gingivalis W50 infection. AAV-mediated Atp6v1c1 knockdown dramatically reduced osteoclast numbers and inhibited the infiltration of dendritic cells and macrophages in the bacteria-induced inflammatory lesions in periodontitis. Silencing of Atp6v1c1 expression also prevented the expressions of osteoclast-related genes and pro-inflammatory cytokine genes. Our data suggests that AAV-shRNA-Atp6v1c1 treatment can significantly attenuate the bone erosion and inflammation caused by periodontitis, indicating the dual function of AAV-shRNA-Atp6v1c1 as an inhibitor of bone erosion mediated by osteoclasts, and as an inhibitor of inflammation through down-regulation of pro-inflammatory cytokine expression. This study demonstrated that Atp6v1c1 RNAi knockdown gene therapy mediated by AAV-shRNA-Atp6v1c1 is a promising novel therapeutic approach for the treatment of bone erosion and inflammatory related diseases, such as periodontitis and rheumatoid arthritis.
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Affiliation(s)
- Sheng Li
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, United States of America
- College of Stomatology, Nanjing Medical University, Nanjing, 210029, People’s Republic of China
| | - Liang Hao
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, United States of America
| | - Lin Wang
- College of Stomatology, Nanjing Medical University, Nanjing, 210029, People’s Republic of China
| | - Yun Lu
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, United States of America
| | - Qian Li
- Life Science College, Zhejiang University, 388 Yuhang Road, Hangzhou, 310058, People's Republic of China
| | - Zheng Zhu
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, United States of America
- College of Stomatology, Nanjing Medical University, Nanjing, 210029, People’s Republic of China
| | - Jian-Zhong Shao
- Life Science College, Zhejiang University, 388 Yuhang Road, Hangzhou, 310058, People's Republic of China
| | - Wei Chen
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, United States of America
- * E-mail:
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13
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Zhu Z, Chen W, Hao L, Zhu G, Lu Y, Li S, Wang L, Li YP. Ac45 silencing mediated by AAV-sh-Ac45-RNAi prevents both bone loss and inflammation caused by periodontitis. J Clin Periodontol 2015; 42:599-608. [PMID: 25952706 DOI: 10.1111/jcpe.12415] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2015] [Indexed: 02/05/2023]
Abstract
AIM Periodontitis induced by oral pathogens leads to severe periodontal tissue damage and osteoclast-mediated bone resorption caused by inflammation. On the basis of the importance of Ac45 in osteoclast formation and function, we performed this study to evaluate the therapeutic potential of periodontitis by local adeno-associated virus (AAV)-mediated Ac45 gene knockdown. MATERIAL AND METHODS We used AAV-mediated short hairpin RNAi knockdown of Ac45 gene expression (AAV-sh-Ac45) to inhibit bone erosion and gingival inflammation simultaneously in a well-established periodontitis mouse model induced by Porphyromonas gingivalis W50. Histological studies were performed to evaluate the bone protection of AAV-sh-Ac45. Immunochemistry, ELISA and qRT-PCR were performed to reveal the role of Ac45 knockdown on inflammation, immune response and expression of cytokine. RESULTS We found that Ac45 knockdown impaired osteoclast-mediated extracellular acidification and bone resorption in vitro and in vivo. Furthermore, local administration of AAV-sh-Ac45 protected mice from bone erosion by >85% and attenuated inflammation and decreased infiltration of T cells, dendritic cells and macrophages in the periodontal lesion. Notably, the expression of pro-inflammatory cytokines was also reduced. CONCLUSIONS Local AAV-sh-Ac45 gene therapy efficiently protects against periodontal tissue damage and bone erosion through both inhibition of osteoclast function and attenuating inflammation, and may represent a powerful new treatment strategy for periodontitis.
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Affiliation(s)
- Zheng Zhu
- Jiangsu Key Laboratory of Oral Diseases, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.,Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wei Chen
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Liang Hao
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Guochun Zhu
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yun Lu
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sheng Li
- Jiangsu Key Laboratory of Oral Diseases, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.,Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lin Wang
- Jiangsu Key Laboratory of Oral Diseases, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
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14
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Jules J, Yang S, Chen W, Li YP. Role of Regulators of G Protein Signaling Proteins in Bone Physiology and Pathophysiology. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:47-75. [PMID: 26123302 DOI: 10.1016/bs.pmbts.2015.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Regulators of G protein signaling (RGS) proteins enhance the intrinsic GTPase activity of α subunits of the heterotrimeric G protein complex of G protein-coupled receptors (GPCRs) and thereby inactivate signal transduction initiated by GPCRs. The RGS family consists of nearly 37 members with a conserved RGS homology domain which is critical for their GTPase accelerating activity. RGS proteins are expressed in most tissues, including heart, lung, brain, kidney, and bone and play essential roles in many physiological and pathological processes. In skeletal development and bone homeostasis as well as in many bone disorders, RGS proteins control the functions of various GPCRs, including the parathyroid hormone receptor type 1 and calcium-sensing receptor and also regulate various critical signaling pathways, such as Wnt and calcium oscillations. This chapter will discuss the current findings on the roles of RGS proteins in regulating signaling of key GPCRs in skeletal development and bone homeostasis. We also will examine the current updates of RGS proteins' regulation of calcium oscillations in bone physiology and highlight the roles of RGS proteins in selected bone pathological disorders. Despite the recent advances in bone and mineral research, RGS proteins remain understudied in the skeletal system. Further understanding of the roles of RGS proteins in bone should not only provide great insights into the molecular basis of various bone diseases but also generate great therapeutic drug targets for many bone diseases.
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Affiliation(s)
- Joel Jules
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Shuying Yang
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, New York, USA; Developmental Genomics Group, New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Wei Chen
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yi-Ping Li
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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15
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Woodard GE, Jardín I, Berna-Erro A, Salido GM, Rosado JA. Regulators of G-protein-signaling proteins: negative modulators of G-protein-coupled receptor signaling. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 317:97-183. [PMID: 26008785 DOI: 10.1016/bs.ircmb.2015.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Regulators of G-protein-signaling (RGS) proteins are a category of intracellular proteins that have an inhibitory effect on the intracellular signaling produced by G-protein-coupled receptors (GPCRs). RGS along with RGS-like proteins switch on through direct contact G-alpha subunits providing a variety of intracellular functions through intracellular signaling. RGS proteins have a common RGS domain that binds to G alpha. RGS proteins accelerate GTPase and thus enhance guanosine triphosphate hydrolysis through the alpha subunit of heterotrimeric G proteins. As a result, they inactivate the G protein and quickly turn off GPCR signaling thus terminating the resulting downstream signals. Activity and subcellular localization of RGS proteins can be changed through covalent molecular changes to the enzyme, differential gene splicing, and processing of the protein. Other roles of RGS proteins have shown them to not be solely committed to being inhibitors but behave more as modulators and integrators of signaling. RGS proteins modulate the duration and kinetics of slow calcium oscillations and rapid phototransduction and ion signaling events. In other cases, RGS proteins integrate G proteins with signaling pathways linked to such diverse cellular responses as cell growth and differentiation, cell motility, and intracellular trafficking. Human and animal studies have revealed that RGS proteins play a vital role in physiology and can be ideal targets for diseases such as those related to addiction where receptor signaling seems continuously switched on.
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Affiliation(s)
- Geoffrey E Woodard
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA; Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Isaac Jardín
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - A Berna-Erro
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - Gines M Salido
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - Juan A Rosado
- Department of Physiology, University of Extremadura, Caceres, Spain
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16
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Feng S, Cai M, Liu P, Wei L, Wang J, Qi J, Deng L. Atp6v1c1 may regulate filament actin arrangement in breast cancer cells. PLoS One 2014; 9:e84833. [PMID: 24454753 PMCID: PMC3893128 DOI: 10.1371/journal.pone.0084833] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/19/2013] [Indexed: 01/26/2023] Open
Abstract
Previous studies have shown that the rate of breast cancer metastasis correlates with the expression of vacuolar H+-ATPases (V-ATPases). However, how V-ATPase is involved in breast cancer metastasis remains unknown. Our previous study showed that Atp6v1c1-depleted osteoclasts did not form organized actin rings and that Atp6v1c1 co-localizes with F-actin. In this study, we found that the normal arrangement of filamentous actin is disrupted in Atp6v1c1-depleted 4T1 mouse breast cancer cells and in the ATP6V1C1-depleted human breast cancer cell lines MDA-MB-231 and MDA-MB-435s. We further found that Atp6v1c1 co-localizes with F-actin in 4T1 cells. The results of our study suggest that high expression of Atp6v1c1 affects the actin structure of cancer cells such that it facilitates breast cancer metastasis. The findings also indicate that Atp6v1c1 could be a novel target for breast cancer metastasis therapy.
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Affiliation(s)
- Shengmei Feng
- 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, China
- * E-mail: (SMF); (LFD)
| | - Ming Cai
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Pengcheng Liu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Li Wei
- 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, China
| | - Jinshen Wang
- 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, China
| | - Jin Qi
- 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, China
| | - Lianfu Deng
- 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, China
- * E-mail: (SMF); (LFD)
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17
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Keinan D, Yang S, Cohen RE, Yuan X, Liu T, Li YP. Role of regulator of G protein signaling proteins in bone. Front Biosci (Landmark Ed) 2014; 19:634-48. [PMID: 24389209 DOI: 10.2741/4232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Regulators of G protein signaling (RGS) proteins are a family with more than 30 proteins that all contain an RGS domain. In the past decade, increasing evidence has indicated that RGS proteins play crucial roles in the regulation of G protein coupling receptors (GPCR), G proteins, and calcium signaling during cell proliferation, migration, and differentiation in a variety of tissues. In bone, those proteins modulate bone development and remodeling by influencing various signaling pathways such as GPCR-G protein signaling, Wnt, calcium oscillations and PTH. This review summarizes the recent advances in the understanding of the regulation of RGS gene expression, as well as the functions and mechanisms of RGS proteins, especially in regulating GPCR-G protein signaling, Wnt signaling, calcium oscillations signaling and PTH signaling during bone development and remodeling. This review also highlights the regulation of different RGS proteins in osteoblasts, chondrocytes and osteoclasts. The knowledge from the recent advances of RGS study summarized in the review would provide the insights into new therapies for bone diseases.
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Affiliation(s)
- David Keinan
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY 14214
| | - Shuying Yang
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY 14214
| | - Robert E Cohen
- Department of Periodontics and Endodontics, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Xue Yuan
- Department of Oral Biology School of Dental Medicine, University at Buffalo, The State University of New York, B36 Foster Hall, Buffalo, NY 14214
| | - Tongjun Liu
- Department of Oral Biology School of Dental Medicine, University at Buffalo, The State University of New York, B36 Foster Hall, Buffalo, NY 14214
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham (UAB), 1825 University Blvd, Birmingham AL 35294, USA
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18
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Yang S, Hao L, McConnell M, Zhou X, Wang M, Zhang Y, Mountz JD, Reddy M, Eleazer PD, Li YP, Chen W. Inhibition of Rgs10 Expression Prevents Immune Cell Infiltration in Bacteria-induced Inflammatory Lesions and Osteoclast-mediated Bone Destruction. Bone Res 2013; 1:267-281. [PMID: 24761229 DOI: 10.4248/br201303005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Regulator of G-protein Signaling 10 (Rgs10) plays an important function in osteoclast differentiation. However, the role of Rgs10 in immune cells and inflammatory responses, which activate osteoclasts in inflammatory lesions, such as bacteria-induced periodontal disease lesions, remains largely unknown. In this study, we used an adeno-associated virus (AAV-) mediated RNAi (AAV-shRNA-Rgs10) knockdown approach to study Rgs10's function in immune cells and osteoclasts in bacteria-induced inflammatory lesions in a mouse model of periodontal disease. We found that AAV-shRNA-Rgs10 mediated Rgs10 knockdown impaired osteoclastogenesis and osteoclast-mediated bone resorption, in vitro and in vivo. Interestingly, local injection of AAV-shRNA-Rgs10 into the periodontal tissues in the bacteria-induced inflammatory lesion greatly decreased the number of dendritic cells, T-cells and osteoclasts, and protected the periodontal tissues from local inflammatory damage and bone destruction. Importantly, AAV-mediated Rgs10 knockdown also reduced local expression of osteoclast markers and pro-inflammatory cytokines. Our results demonstrate that AAV-shRNA-Rgs10 knockdown in periodontal disease tissues can prevent bone resorption and inflammation simultaneously. Our data indicate that Rgs10 may regulate dendritic cell proliferation and maturation, as well as the subsequent stimulation of T-cell proliferation and maturation, and osteoclast differentiation and activation. Our study suggests that AAV-shRNA-Rgs10 can be useful as a therapeutic treatment of periodontal disease.
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Affiliation(s)
- Sen Yang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Liang Hao
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Matthew McConnell
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Xuedong Zhou
- The State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Sichuan, P. R. China
| | - Min Wang
- The State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Sichuan, P. R. China
| | - Yan Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - John D Mountz
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michael Reddy
- Department of Periodontology, University of Alabama at Birmingham School of Dentistry, Birmingham, Alabama, USA
| | - Paul D Eleazer
- Department of Endodontics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Wei Chen
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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19
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RNA interference-mediated silencing of Atp6i prevents both periapical bone erosion and inflammation in the mouse model of endodontic disease. Infect Immun 2013; 81:1021-30. [PMID: 23166162 DOI: 10.1128/iai.00756-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dental caries is one of the most prevalent infectious diseases in the United States, affecting approximately 80% of children and the majority of adults. Dental caries may lead to endodontic disease, where the bacterial infection progresses to the root canal system of the tooth, leading to periapical inflammation, bone erosion, severe pain, and tooth loss. Periapical inflammation may also exacerbate inflammation in other parts of the body. Although conventional clinical therapies for this disease are successful in approximately 80% of cases, there is still an urgent need for increased efficacy of treatment. In this study, we applied a novel gene-therapeutic approach using recombinant adeno-associated virus (AAV)-mediated Atp6i RNA interference (RNAi) knockdown of Atp6i/TIRC7 gene expression to simultaneously target periapical bone resorption and periapical inflammation. We found that Atp6i inhibition impaired osteoclast function in vitro and in vivo and decreased the number of T cells in the periapical lesion. Notably, AAV-mediated Atp6i/TIRC7 knockdown gene therapy reduced bacterial infection-stimulated bone resorption by 80% in the mouse model of endodontic disease. Importantly, Atp6i(+/-) mice with haploinsufficiency of Atp6i exhibited protection similar to that in mice with bacterial infection-stimulated bone erosion and periapical inflammation, which confirms the potential therapeutic effect of AAV-small hairpin RNA (shRNA)-Atp6i/TIRC7. Our results demonstrate that AAV-mediated Atp6i/TIRC7 knockdown in periapical tissues can inhibit endodontic disease development, bone resorption, and inflammation, indicating for the first time that this potential gene therapy may significantly improve the health of those who suffer from endodontic disease.
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20
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Jiang H, Chen W, Zhu G, Zhang L, Tucker B, Hao L, Feng S, Ci H, Ma J, Wang L, Stashenko P, Li YP. RNAi-mediated silencing of Atp6i and Atp6i haploinsufficiency prevents both bone loss and inflammation in a mouse model of periodontal disease. PLoS One 2013; 8:e58599. [PMID: 23577057 PMCID: PMC3618217 DOI: 10.1371/journal.pone.0058599] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 02/07/2013] [Indexed: 12/29/2022] Open
Abstract
Periodontal disease affects about 80% of adults in America, and is characterized by oral bacterial infection-induced gingival inflammation, oral bone resorption, and tooth loss. Periodontitis is also associated with other diseases such as rheumatoid arthritis, diabetes, and heart disease. Although many efforts have been made to develop effective therapies for this disease, none have been very effective and there is still an urgent need for better treatments and preventative strategies. Herein we explored for the first time the possibility that adeno-associated virus (AAV)-mediated RNAi knockdown could be used to treat periodontal disease with improved efficacy. For this purpose, we used AAV-mediated RNAi knockdown of Atp6i/TIRC7 gene expression to target bone resorption and gingival inflammation simultaneously. Mice were infected with the oral pathogen Porphyromonas gingivalis W50 (P. gingivalis) in the maxillary periodontium to induce periodontitis. We found that Atp6i depletion impaired extracellular acidification and osteoclast-mediated bone resorption. Furthermore, local injection of AAV-shRNA-Atp6i/TIRC7 into the periodontal tissues in vivo protected mice from P. gingivalis infection-stimulated bone resorption by >85% and decreased the T-cell number in periodontal tissues. Notably, AAV-mediated Atp6i/TIRC7 knockdown also reduced the expression of osteoclast marker genes and inflammation-induced cytokine genes. Atp6i(+/-) mice with haploinsufficiency were similarly protected from P. gingivalis infection-stimulated bone loss and gingival inflammation. This suggests that AAV-shRNA-Atp6i/TIRC7 therapeutic treatment may significantly improve the health of millions who suffer from P. gingivalis-mediated periodontal disease.
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Affiliation(s)
- Hongbing Jiang
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
- College of Stomatology, Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
| | - Wei Chen
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
| | - Guochun Zhu
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
| | - Lijie Zhang
- Department of Immunology and Infectious Disease, The Forsyth Institute, Cambridge, Massachusetts, United States of America
- Department of Clinical Laboratory, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, People's Republic of China
| | - Byron Tucker
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
- Harvard School of Dental Medicine Department of Restorative Dentistry and in Endodontics, Boston, Massachusetts, United States of America
| | - Liang Hao
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
| | - Shengmei Feng
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
| | - Hongliang Ci
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
| | - Junqing Ma
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
- College of Stomatology, Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
| | - Lin Wang
- College of Stomatology, Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
| | - Philip Stashenko
- Department of Immunology and Infectious Disease, The Forsyth Institute, Cambridge, Massachusetts, United States of America
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham, Alabama, United States of America
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Zhang Y, Zhang H, Zhuang C, Liu R, Wei J. MSRApolymorphism is associated with the risk of rheumatoid arthritis in a Chinese population. Scand J Rheumatol 2012; 42:91-6. [DOI: 10.3109/03009742.2012.730626] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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22
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Wang W, Olson D, Liang G, Franceschi RT, Li C, Wang B, Wang SS, Yang S. Collagen XXIV (Col24α1) promotes osteoblastic differentiation and mineralization through TGF-β/Smads signaling pathway. Int J Biol Sci 2012; 8:1310-22. [PMID: 23139630 PMCID: PMC3492790 DOI: 10.7150/ijbs.5136] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/01/2012] [Indexed: 12/19/2022] Open
Abstract
Collagen XXIV (Col24α1) is a recently discovered fibrillar collagen. It is known that mouse Col24α1 is predominantly expressed in the forming skeleton of the mouse embryo, as well as in the trabecular bone and periosteum of the newborn mouse. However, the role and mechanism of Col24α1 in osteoblast differentiation and mineralization remains unclear. By analyzing the expression pattern of Col24α1, we confirmed that it is primarily expressed in bone tissues, and this expression gradually increased concomitant with the progression of osteoblast differentiation. Through the use of a lentivirus vector-mediated interference system, silencing Col24α1 expression in MC3T3-E1 murine preosteoblastic cells resulted in significant inhibition of alkaline phosphatase (ALP) activity, cell mineralization, and the expression of osteoblast marker genes such as runt-related transcription factor 2 (Runx2), osteocalcin (OCN), ALP, and type I collagen (Col I). Subsequent overexpression not only rescued the deficiency in osteoblast differentiation from Col24α1 silenced cells, but also enhanced osteoblastic differentiation in control cells. We further revealed that Col24α1 interacts with integrin β3, and silencing Col24α1 up-regulated the expression of Smad7 during osteoblast differentiation while at the same time inhibiting the phosphorylation of the Smad2/3 complex. These results suggest that Col24α1 imparts some of its regulatory control on osteoblast differentiation and mineralization at least partially through interaction with integrin β3 and the transforming growth factor beta (TGF-β) /Smads signaling pathway.
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Affiliation(s)
- Weizhuo Wang
- Department of Oral Biology, School of Dental Medicine, University of Buffalo, State University of New York, Buffalo, NY 14214, USA
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23
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Liu JJ, Ma X, Cai LB, Cui YG, Liu JY. Downregulation of both gene expression and activity of Hsp27 improved maturation of mouse oocyte in vitro. Reprod Biol Endocrinol 2010; 8:47. [PMID: 20465849 PMCID: PMC2890611 DOI: 10.1186/1477-7827-8-47] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 05/14/2010] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Heat shock protein 27 (Hsp27), a member of the small heat shock protein family, is an apoptosis regulator. Our previous proteomic study showed that Hsp27 mainly expressed in human oocyte, and that Hsp27 expression was downregulated in the ovaries derived from women with the polycystic ovary syndrome (PCOS), a well known endocrinal disorder with abnormal apoptotic activity and folliculogenesis. However, the exact effects of Hsp27 downregulation on oocyte development have not yet been clarified. METHODS The expression of Hsp27 gene was downregulated in the mouse oocytes cultured in vitro using siRNA adenovirus infection, while the activity of Hsp27 was decreased by microinjection of polyclonal Hsp27 antibody into the cytoplasm of germinal vesicle (GV) oocytes. Oocyte maturation rate was evaluated by morphological observation. Early stage of apoptosis was determined using Annexin-V staining analysis and some critical apoptotic factors and cytokines were also monitored at both mRNA level by real time RT-PCR and protein expression level by immunofluorescence and western blot. RESULTS Hsp27 expressed at high level in maturing oocytes. Infection with AdshHsp27, and microinjection of Hsp27 antibody into GV oocytes, resulted in the improved oocyte development and maturation. Germinal vesicle breakdown (GVBD) rates were significantly increased in two AdshHsp27-treated groups (88.7%, 86.0%) and Hsp27 antibody-injected group (77.0%) when compared with control (76.2% in AdGFP, 64.4% in IgG-injected), respectively. In addition, the rates of metaphase II (MII) development in two AdshHsp27-treated groups (73.8%, 76.4%) and Hsp27 antibody-injected group (67.3%) were higher than that in the controls (59.6% in AdGFP, 55.1% in IgG-injected). We also found that the rates of early stage of apoptosis in Hsp27 downregulated groups (46.5% and 45.6%) were higher than that in control group (34.1%) after 8 h of IVM. Similarly, downregulation of Hsp27 caused a significantly enhanced the expression of apoptotic factors (caspase 8, caspase 3) and cytokines (bmp 15 and gdf 9). CONCLUSIONS Downregulation of Hsp27 improved the maturation of mouse oocytes, while increased early stage of apoptosis in oocytes by inducing the activation of extrinsic, caspase 8-mediated pathway.
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Affiliation(s)
- Jin-Juan Liu
- Department of life science and technology, China Pharmaceutical University, Nanjing 210038, China
- Center of Clinical Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Xiang Ma
- Center of Clinical Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Ling-Bo Cai
- Center of Clinical Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Yu-Gui Cui
- Center of Clinical Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Jia-Yin Liu
- Department of life science and technology, China Pharmaceutical University, Nanjing 210038, China
- Center of Clinical Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
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24
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Coman DJ, Murray DW, Byrne JC, Rudd PM, Bagaglia PM, Doran PD, Treacy EP. Galactosemia, a single gene disorder with epigenetic consequences. Pediatr Res 2010; 67:286-92. [PMID: 19952866 DOI: 10.1203/pdr.0b013e3181cbd542] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Long-term outcomes of classic galactosemia (GAL) remain disappointing. It is unclear if the complications result mainly from prenatal-neonatal toxicity or persistent glycoprotein and glycolipid synthesis abnormalities. We performed gene expression profiling (T transcriptome) to characterize key-altered genes and gene clusters of four patients with GAL with variable outcomes maintained on a galactose-restricted diet, compared with controls. Significant perturbations of multiple cell signaling pathways were observed including mitogen-activated protein kinase (MAPK) signaling, regulation of the actin cytoskeleton, focal adhesion, and ubiquitin mediated proteolysis. A number of genes significantly altered were further investigated in the GAL cohort including SPARC (osteonectin) and S100A8 (S100 calcium-binding protein). The whole serum N-glycan profile and IgG glycosylation status of 10 treated patients with GAL were compared with healthy control serum and IgG using a quantitative high-throughput analytical HPLC platform. Increased levels of agalactosylated and monogalactosylated structures and decreases in certain digalactosylated structures were identified in the patients. The persistent abnormal glycosylation of serum glycoproteins seen with the microarray data indicates persisting metabolic dyshomeostasis and gene dysregulation in "treated" GAL. Strict restriction of dietary galactose is clearly life saving in the neonatal period; long-term severe galactose restriction may contribute to ongoing systemic abnormalities.
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Affiliation(s)
- David J Coman
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Dublin 1, Ireland
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Atp6v0d2 is an essential component of the osteoclast-specific proton pump that mediates extracellular acidification in bone resorption. J Bone Miner Res 2009; 24:871-85. [PMID: 19113919 PMCID: PMC2672205 DOI: 10.1359/jbmr.081239] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Bone resorption relies on the extracellular acidification function of vacuolar (V-) ATPase proton pump(s) present in the plasma membrane of osteoclasts. The exact configuration of osteoclast-specific V-ATPases remains largely unknown. In this study, we found that Atp6v0d2 (d2), an isoform of the d subunit in the V-ATPase, showed 5-fold higher expression than that of Atp6v0d1 (d1) in mature osteoclasts, indicating a potential function in osteoclastic bone resorption. When d2 was depleted at an early stage of RANKL-induced osteoclast differentiation in vitro, formation of multinucleated cells was severely impaired. However, depletion of d2 at a late differentiation stage did not affect osteoclast fusion but did abolish the activity of extracellular acidification and bone resorption of mature osteoclasts. We also showed the association of the two tagged-proteins d2 and a3 when co-expressed in mammalian cells with a co-immunoprecipitation assay. Moreover, glutathione-S-transferase (GST) pull-down assay showed the direct interaction of d2 with the N terminus of Atp6v0a3 (a3), which is the functionally identified osteoclast-specific component of V-ATPase. Therefore, our results show the dual function of d2 as a regulator of cell fusion in osteoclast differentiation and as an essential component of the osteoclast-specific proton pump that mediates extracellular acidification in bone resorption.
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26
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Soltanoff CS, Yang S, Chen W, Li YP. Signaling networks that control the lineage commitment and differentiation of bone cells. Crit Rev Eukaryot Gene Expr 2009; 19:1-46. [PMID: 19191755 DOI: 10.1615/critreveukargeneexpr.v19.i1.10] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Osteoblasts and osteoclasts are the two major bone cells involved in the bone remodeling process. Osteoblasts are responsible for bone formation while osteoclasts are the bone-resorbing cells. The major event that triggers osteogenesis and bone remodeling is the transition of mesenchymal stem cells into differentiating osteoblast cells and monocyte/macrophage precursors into differentiating osteoclasts. Imbalance in differentiation and function of these two cell types will result in skeletal diseases such as osteoporosis, Paget's disease, rheumatoid arthritis, osteopetrosis, periodontal disease, and bone cancer metastases. Osteoblast and osteoclast commitment and differentiation are controlled by complex activities involving signal transduction and transcriptional regulation of gene expression. Recent advances in molecular and genetic studies using gene targeting in mice enable a better understanding of the multiple factors and signaling networks that control the differentiation process at a molecular level. This review summarizes recent advances in studies of signaling transduction pathways and transcriptional regulation of osteoblast and osteoclast cell lineage commitment and differentiation. Understanding the signaling networks that control the commitment and differentiation of bone cells will not only expand our basic understanding of the molecular mechanisms of skeletal development but will also aid our ability to develop therapeutic means of intervention in skeletal diseases.
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Affiliation(s)
- Carrie S Soltanoff
- Department of Cytokine Biology, The Forsyth Institute, Boston, MA 02115, USA
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27
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Atp6v1c1 is an essential component of the osteoclast proton pump and in F-actin ring formation in osteoclasts. Biochem J 2009; 417:195-203. [PMID: 18657050 DOI: 10.1042/bj20081073] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bone resorption relies on the extracellular acidification function of V-ATPase (vacuolar-type proton-translocating ATPase) proton pump(s) present in the plasma membrane of osteoclasts. The exact configuration of the osteoclast-specific ruffled border V-ATPases remains largely unknown. In the present study, we found that the V-ATPase subunit Atp6v1c1 (C1) is highly expressed in osteoclasts, whereas subunits Atp6v1c2a (C2a) and Atp6v1c2b (C2b) are not. The expression level of C1 is highly induced by RANKL [receptor activator for NF-kappaB (nuclear factor kappaB) ligand] during osteoclast differentiation; C1 interacts with Atp6v0a3 (a3) and is mainly localized on the ruffled border of activated osteoclasts. The results of the present study show for the first time that C1-silencing by lentivirus-mediated RNA interference severely impaired osteoclast acidification activity and bone resorption, whereas cell differentiation did not appear to be affected, which is similar to a3 silencing. The F-actin (filamentous actin) ring formation was severely defected in C1-depleted osteoclasts but not in a3-depleted and a3(-/-) osteoclasts. C1 co-localized with microtubules in the plasma membrane and its vicinity in mature osteoclasts. In addition, C1 co-localized with F-actin in the cytoplasm; however, the co-localization chiefly shifted to the cell periphery of mature osteoclasts. The present study demonstrates that Atp6v1c1 is an essential component of the osteoclast proton pump at the osteoclast ruffled border and that it may regulate F-actin ring formation in osteoclast activation.
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28
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Boyce BF, Xing L. Functions of RANKL/RANK/OPG in bone modeling and remodeling. Arch Biochem Biophys 2008; 473:139-46. [PMID: 18395508 DOI: 10.1016/j.abb.2008.03.018] [Citation(s) in RCA: 1178] [Impact Index Per Article: 73.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 12/11/2022]
Abstract
The discovery of the RANKL/RANK/OPG system in the mid 1990s for the regulation of bone resorption has led to major advances in our understanding of how bone modeling and remodeling are regulated. It had been known for many years before this discovery that osteoblastic stromal cells regulated osteoclast formation, but it had not been anticipated that they would do this through expression of members of the TNF superfamily: receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG), or that these cytokines and signaling through receptor activator of NF-kappaB (RANK) would have extensive functions beyond regulation of bone remodeling. RANKL/RANK signaling regulates osteoclast formation, activation and survival in normal bone modeling and remodeling and in a variety of pathologic conditions characterized by increased bone turnover. OPG protects bone from excessive resorption by binding to RANKL and preventing it from binding to RANK. Thus, the relative concentration of RANKL and OPG in bone is a major determinant of bone mass and strength. Here, we review our current understanding of the role of the RANKL/RANK/OPG system in bone modeling and remodeling.
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Affiliation(s)
- Brendan F Boyce
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, NY 14642, USA.
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