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Gao M, Dong C, Chen Z, Jiang R, Shaw P, Gao W, Sun Y. Different impact of short-term and long-term hindlimb disuse on bone homeostasis. Gene 2024; 918:148457. [PMID: 38641071 DOI: 10.1016/j.gene.2024.148457] [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: 11/14/2023] [Revised: 02/19/2024] [Accepted: 04/08/2024] [Indexed: 04/21/2024]
Abstract
Disuse osteoporosis is one of the major problems of bone health which commonly occurs in astronauts during long-term spaceflight and bedridden patients. However, the mechanisms underlying such mechanical unloading induced bone loss have not been fully understood. In this study, we employed hindlimb-unloading mice models with different length of tail suspension to investigate if the bone loss was regulated by distinct factors under different duration of disuse. Our micro-CT results showed more significant decrease of bone mass in 6W (6-week) tail-suspension mice compared to the 1W (1-week) tail-suspension ones, as indicated by greater reduction of BV/TV, Tb.N, B.Ar/T.Ar and Ct.Th. RNA-sequencing results showed significant effects of hindlimb disuse on cell locomotion and immune system process which could cause bone loss.Real-time quantitative PCR results indicated a greater number of bone formation related genes that were downregulated in short-term tail-suspension mice compared to the long-term ones. It is, thus, suggested while sustained hindlimb unloading continuously contributes to bone loss, molecular regulation of bone homeostasis tends to reach a balance during this process.
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Affiliation(s)
- Minhao Gao
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Chengji Dong
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Zhuliu Chen
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Renhao Jiang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Peter Shaw
- Oujiang Lab, Zhejiang Lab for Regenerative Medicine, Vision and Brain Health, Wenzhou, Zhejiang 325000, China
| | - Weiyang Gao
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
| | - Yuanna Sun
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
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2
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Lu D, Lu J, Liu Q, Zhang Q. Emerging role of the RNA-editing enzyme ADAR1 in stem cell fate and function. Biomark Res 2023; 11:61. [PMID: 37280687 DOI: 10.1186/s40364-023-00503-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 05/13/2023] [Indexed: 06/08/2023] Open
Abstract
Stem cells are critical for organism development and the maintenance of tissue homeostasis. Recent studies focusing on RNA editing have indicated how this mark controls stem cell fate and function in both normal and malignant states. RNA editing is mainly mediated by adenosine deaminase acting on RNA 1 (ADAR1). The RNA editing enzyme ADAR1 converts adenosine in a double-stranded RNA (dsRNA) substrate into inosine. ADAR1 is a multifunctional protein that regulate physiological processes including embryonic development, cell differentiation, and immune regulation, and even apply to the development of gene editing technologies. In this review, we summarize the structure and function of ADAR1 with a focus on how it can mediate distinct functions in stem cell self-renewal and differentiation. Targeting ADAR1 has emerged as a potential novel therapeutic strategy in both normal and dysregulated stem cell contexts.
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Affiliation(s)
- Di Lu
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Jianxi Lu
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Qiuli Liu
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
| | - Qi Zhang
- The Biotherapy Center, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
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3
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Mendez Ruiz S, Chalk AM, Goradia A, Heraud-Farlow J, Walkley C. Over-expression of ADAR1 in mice does not initiate or accelerate cancer formation in vivo. NAR Cancer 2023; 5:zcad023. [PMID: 37275274 PMCID: PMC10233902 DOI: 10.1093/narcan/zcad023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/27/2023] [Accepted: 05/16/2023] [Indexed: 06/07/2023] Open
Abstract
Adenosine to inosine editing (A-to-I) in regions of double stranded RNA (dsRNA) is mediated by adenosine deaminase acting on RNA 1 (ADAR1) or ADAR2. ADAR1 and A-to-I editing levels are increased in many human cancers. Inhibition of ADAR1 has emerged as a high priority oncology target, however, whether ADAR1 overexpression enables cancer initiation or progression has not been directly tested. We established a series of in vivo models to allow overexpression of full-length ADAR1, or its individual isoforms, to test if increased ADAR1 expression was oncogenic. Widespread over-expression of ADAR1 or the p110 or p150 isoforms individually as sole lesions was well tolerated and did not result in cancer initiation. Therefore, ADAR1 overexpression alone is not sufficient to initiate cancer. We demonstrate that endogenous ADAR1 and A-to-I editing increased upon immortalization in murine cells, consistent with the observations from human cancers. We tested if ADAR1 over-expression could co-operate with cancer initiated by loss of tumour suppressors using a model of osteosarcoma. We did not see a disease potentiating or modifying effect of overexpressing ADAR1 or its isoforms in the models assessed. We conclude that increased ADAR1 expression and A-to-I editing in cancers is most likely a consequence of tumor formation.
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Affiliation(s)
- Shannon Mendez Ruiz
- St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Alistair M Chalk
- St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Medicine, Eastern Hill Precinct, Melbourne Medical School, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Ankita Goradia
- St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | | | - Carl R Walkley
- To whom correspondence should be addressed. Tel: +61 3 9231 2480;
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4
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Shi S, Chen S, Wang M, Guo B, He Y, Chen H. Clinical relevance of RNA editing profiles in lung adenocarcinoma. Front Genet 2023; 14:1084869. [PMID: 36999050 PMCID: PMC10043753 DOI: 10.3389/fgene.2023.1084869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Background: Lung adenocarcinoma (LUAD) is the most frequently occurring lung cancer worldwide, with increasing death rates. It belongs to the non-small cell lung cancer (NSCLC) type and has a strong association with previous smoking history. Growing evidence has demonstrated the significance of adenosine-to-inosine RNA editing (ATIRE) dysregulation in cancer. The aim of the present study was to evaluate ATIRE events that might be clinically useful or tumorigenic.Methods: To explore survival-related ATIRE events in LUAD, its ATIRE profiles, gene expression data, and corresponding patients’ clinical information were downloaded from the Cancer Genome Atlas (TCGA) and the synapse database. We evaluated 10441 ATIRE in 440 LUAD patients from the TCGA database. ATIRE profiles were merged with TCGA survival data. We selected prognostic ATIRE sites, using a univariate Cox analysis (p < 0.001). Cox proportional hazards regression and lasso regression analysis were used to determine survival-related ATIRE sites, create risk ratings for those sites, and build a prognostic model and a nomogram for assessing overall survival (OS). Six ATIRE sites were used in the prognostic model construction and patients were randomly divided into a validation cohort (n = 176) and a training cohort (n = 264). The “Pheatmap” program was used to create risk curves that included risk score, survival time, and expression of ATIRE sites. We also determined the clinical prediction model’s discrimination. The decision curve analysis and the 1-, 2-, and 3-year corrective curves were simultaneously used to evaluate the nomogram. We also evaluated the relationship between the amount of ATIRE sites and host gene expression and the impact of ATIRE expression on transcriptome expression.Results: The pyroglutamyl-peptidase I (PGPEP1) chr19:18476416A > I, ankyrin repeat domain 36B pseudogene 1 (ANKRD36BP1) (dist = 3,795), T-box transcription factor (TBX19) (dist = 29815) chr1:168220463A > I, Syntrophin Beta 2 (SNTB2) chr16:69338598A > I, hook microtubule-tethering protein 3 (HOOK3) chr8:42883441A > I, NADH dehydrogenase flavoprotein 3 (NDUFV3) chr21:44329452A > I, and FK506-binding protein 11 (FKBP11) chr12:49316769A > I were used in the prognostic model construction. High levels of risk score were significantly associated with worse OS and progression-free survival. Tumour stage and risk score were related to OS in LUAD patients. The predictors were among the prognostic nomogram model’s risk score, age, gender, and tumor stage. The calibration plot and C-index (0.718) demonstrated the significant accuracy of nomogram’s predictions. ATIRE level was markedly elevated in tumor tissues and was highly variable between patients.Conclusion: Events involving ATIRE in LUAD were highly functional and clinically relevant. The RNA editing-based model provides a solid framework for further investigation of the functions of RNA editing in non-coding areas and may be used as a unique method for predicting LUAD survival.
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Affiliation(s)
- Si Shi
- The Respiratory Department, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Shibin Chen
- Medical Research Center, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Menghang Wang
- The Respiratory Department, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Bingchen Guo
- Department of Cardiology, The first Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Yaowu He
- The Respiratory Department, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Hong Chen
- The Respiratory Department, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
- *Correspondence: Hong Chen,
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5
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Yang K, Li J, Tao L. Purine metabolism in the development of osteoporosis. Biomed Pharmacother 2022; 155:113784. [DOI: 10.1016/j.biopha.2022.113784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/17/2022] Open
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6
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Garcia-Gonzalez C, Dieterich C, Maroli G, Wiesnet M, Wietelmann A, Li X, Yuan X, Graumann J, Stellos K, Kubin T, Schneider A, Braun T. ADAR1 Prevents Autoinflammatory Processes in the Heart Mediated by IRF7. Circ Res 2022; 131:580-597. [PMID: 36000401 DOI: 10.1161/circresaha.122.320839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND ADAR1 (adenosine deaminase acting on RNA-1)-mediated adenosine to inosine (A-to-I) RNA editing plays an essential role for distinguishing endogenous from exogenous RNAs, preventing autoinflammatory ADAR1 also regulates cellular processes by recoding specific mRNAs, thereby altering protein functions, but may also act in an editing-independent manner. The specific role of ADAR1 in cardiomyocytes and its mode of action in the heart is not fully understood. To determine the role of ADAR1 in the heart, we used different mutant mouse strains, which allows to distinguish immunogenic, editing-dependent, and editing-independent functions of ADAR1. METHODS Different Adar1-mutant mouse strains were employed for gene deletion or specific inactivation of ADAR1 enzymatic activity in cardiomyocytes, either alone or in combination with Ifih1 (interferon induced with helicase C domain 1) or Irf7 (interferon regulatory factor 7) gene inactivation. Mutant mice were investigated by immunofluorescence, Western blot, RNAseq, proteomics, and functional MRI analysis. RESULTS Inactivation of Adar1 in cardiomyocytes resulted in late-onset autoinflammatory myocarditis progressing into dilated cardiomyopathy and heart failure at 6 months of age. Adar1 depletion activated interferon signaling genes but not NFκB (nuclear factor kappa B) signaling or apoptosis and reduced cardiac hypertrophy during pressure overload via induction of Irf7. Additional inactivation of the cytosolic RNA sensor MDA5 (melanoma differentiation-associated gene 5; encoded by the Ifih1 gene) in Adar1 mutant mice prevented activation of interferon signaling gene and delayed heart failure but did not prevent lethality after 8.5 months. In contrast, compound mutants only expressing catalytically inactive ADAR1 in an Ifih1-mutant background were completely normal. Inactivation of Irf7 attenuated the phenotype of Adar1-deficient cardiomyocytes to a similar extent as Ifih1 depletion, identifying IRF7 as the main mediator of autoinflammatory responses caused by the absence of ADAR1 in cardiomyocytes. CONCLUSIONS Enzymatically active ADAR1 prevents IRF7-mediated autoinflammatory reactions in the heart triggered by endogenous nonedited RNAs. In addition to RNA editing, ADAR1 also serves editing-independent roles in the heart required for long-term cardiac function and survival.
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Affiliation(s)
- Claudia Garcia-Gonzalez
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.).,Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Av. Del Hospital Universitario, Oviedo, Spain (C.G.-G.)
| | - Christoph Dieterich
- Department of Internal Medicine III and Klaus Tschira Institute for Computational Cardiology, Section of Bioinformatics and Systems Cardiology, University Hospital, Heidelberg, Germany (C.D.)
| | - Giovanni Maroli
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.)
| | - Marion Wiesnet
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.)
| | - Astrid Wietelmann
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.)
| | - Xiang Li
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.)
| | - Xuejun Yuan
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.)
| | - Johannes Graumann
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.).,German Centre for Cardiovascular Research (DZHK), Partner Sites Rhine-Main and Heidelberg/Mannheim, Bad Nauheim and Mannheim, Germany (J.G., K.S., T.B.)
| | - Konstantinos Stellos
- German Centre for Cardiovascular Research (DZHK), Partner Sites Rhine-Main and Heidelberg/Mannheim, Bad Nauheim and Mannheim, Germany (J.G., K.S., T.B.).,Department of Cardiovascular Research, European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany (K.S.).,Biosciences Institute, Vascular Biology and Medicine Theme, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom (K.S.)
| | - Thomas Kubin
- Department of Cardiac Surgery, Kerckhoff Heart Center, Bad Nauheim, Germany (T.K.)
| | - Andre Schneider
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.)
| | - Thomas Braun
- Max Planck Institute for Heart- and Lung Research, Bad Nauheim, Germany (C.G.-G., G.M., M.W., A.W., X.L., X.Y., J.G., A.S., T.B.).,German Centre for Cardiovascular Research (DZHK), Partner Sites Rhine-Main and Heidelberg/Mannheim, Bad Nauheim and Mannheim, Germany (J.G., K.S., T.B.)
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Gene Expression Profiles of Human Mesenchymal Stromal Cells Derived from Wharton’s Jelly and Amniotic Membrane before and after Osteo-Induction Using NanoString Platform. Curr Issues Mol Biol 2022; 44:4240-4254. [PMID: 36135203 PMCID: PMC9497674 DOI: 10.3390/cimb44090291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/08/2022] [Accepted: 08/21/2022] [Indexed: 11/16/2022] Open
Abstract
The use of perinatal mesenchymal stem cells (MSCs) in bone tissue regeneration and engineering to substitute bone marrow MSCs has drawn great interest due to their high yield, ease of procurement, multilineage differentiation potential and lack of ethical concerns. Although amniotic membrane (AM) and Wharton’s jelly (WJ)-derived MSCs have been widely shown to possess osteogenic differentiation potential, the intrinsic properties determining their osteogenic capacity remain unclear. Here, we compared gene expression profiles of AM- and WJ-MSCs at basal and osteogenic conditions by using the NanoString Stem Cell Panel containing regulatory genes associated with stemness, self-renewal, Wnt, Notch and Hedgehog signalling pathways. At basal condition, WJ-MSCs displayed higher expression in most genes regardless of their functional roles in self-renewal, adhesion, or differentiation signalling pathways. After osteo-induction, elevated expression of self-renewal genes ADAR and PAFAH1B1 was observed in AM-MSCs, while stemness genes MME and ALDH1A1 were upregulated in WJ-MSC. Both MSCs showed differences in genes associated with ligands, receptors and ubiquitin ligases of the Notch pathway. In addition, further evidence was demonstrated in some signalling molecules including CTBPs, protein kinases, phosphatases, RHOA, RAC1. Downstream targets HES1 and JUN especially showed higher expression in non-induced WJ-MSCs. Hedgehog genes initially expressed in both MSCs were downregulated in WJ-MSCs during osteogenesis. This study has provided insights into the intrinsic biological differences that may lead to their discrimination in therapeutic intervention.
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Guo X, Liu S, Yan R, Nguyen V, Zenati M, Billiar TR, Wang Q. ADAR1 RNA editing regulates endothelial cell functions via the MDA-5 RNA sensing signaling pathway. Life Sci Alliance 2022; 5:5/3/e202101191. [PMID: 34969816 PMCID: PMC8739526 DOI: 10.26508/lsa.202101191] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 11/24/2022] Open
Abstract
The RNA-sensing signaling pathway has been well studied as an essential antiviral mechanism of innate immunity. However, its role in non-infected cells is yet to be thoroughly characterized. Here, we demonstrated that the RNA sensing signaling pathway also reacts to the endogenous cellular RNAs in endothelial cells (ECs), and this reaction is regulated by the RNA-editing enzyme ADAR1. Cellular RNA sequencing analysis showed that EC RNAs endure extensive RNA editing, especially in the RNA transcripts of short interspersed nuclear elements. The EC-specific deletion of ADAR1 dramatically reduced the editing level on short interspersed nuclear element RNAs, resulting in newborn death in mice with damage evident in multiple organs. Genome-wide gene expression analysis revealed a prominent innate immune activation with a dramatically elevated expression of interferon-stimulated genes. However, blocking the RNA sensing signaling pathway by deletion of the cellular RNA receptor MDA-5 prevented interferon-stimulated gene expression and rescued the newborn mice from death. This evidence demonstrated that the RNA-editing/RNA-sensing signaling pathway dramatically modulates EC function, representing a novel molecular mechanism for the regulation of EC functions.
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Affiliation(s)
- Xinfeng Guo
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Silvia Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Pittsburgh Liver Research Center, University of Pittsburgh Medical Center (UPMC) and University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Rose Yan
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Vy Nguyen
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mazen Zenati
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Qingde Wang
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA .,Pittsburgh Liver Research Center, University of Pittsburgh Medical Center (UPMC) and University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,VA Pittsburgh Health System, Pittsburgh, PA, USA
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9
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Centofanti F, Santoro M, Marini M, Visconti VV, Rinaldi AM, Celi M, D’Arcangelo G, Novelli G, Orlandi A, Tancredi V, Tarantino U, Botta A. Identification of Aberrantly-Expressed Long Non-Coding RNAs in Osteoblastic Cells from Osteoporotic Patients. Biomedicines 2020; 8:E65. [PMID: 32204466 PMCID: PMC7148473 DOI: 10.3390/biomedicines8030065] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 02/06/2023] Open
Abstract
Osteoporosis (OP) is a multifactorial disease influenced by genetic, epigenetic, and environmental factors. One of the main causes of the bone homeostasis alteration is inflammation resulting in excessive bone resorption. Long non-coding RNAs (lncRNAs), have a crucial role in regulating many important biological processes in bone, including inflammation. We designed our study to identify lncRNAs misregulated in osteoblast primary cultures derived from OP patients (n = 4), and controls (CTRs, n = 4) with the aim of predicting possible RNA and/or protein targets implicated in this multifactorial disease. We focused on 84 lncRNAs regulating the expression of pro-inflammatory and anti-inflammatory genes and miRNAs. In silico analysis was utilized to predict the interaction of lncRNAs with miRNAs, mRNAs, and proteins targets. Six lncRNAs were significantly down-regulated in OP patients compared to controls: CEP83-AS1, RP11-84C13.1, CTC-487M23.5, GAS5, NCBP2-AS2, and SDCBP2-AS1. Bioinformatic analyses identified HDCA2, PTX3, and FGF2 proteins as downstream targets of CTC-487M23.5, GAS5, and RP11-84C13.1 lncRNAs mediated by the interaction with miRNAs implicated in OP pathogenesis, including miR-21-5p. Altogether, these data open a new regulatory mechanism of gene expression in bone homeostasis and could direct the development of future therapeutic approaches.
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Affiliation(s)
- Federica Centofanti
- Department of Biomedicine and Prevention, Anatomic Pathology Section, University of Rome “Tor Vergata”, 00133 Rome, Italy; (F.C.); (A.O.)
| | | | - Mario Marini
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (M.M.); (A.M.R.); (G.D.); (V.T.)
- Center of Space Biomedicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Virginia Veronica Visconti
- Department of Biomedicine and Prevention, Medical Genetics Section, University of Rome “Tor Vergata”, 00133 Rome, Italy; (V.V.V.); (G.N.)
| | - Anna Maria Rinaldi
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (M.M.); (A.M.R.); (G.D.); (V.T.)
- Center of Space Biomedicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Monica Celi
- Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata”, 00133 Rome, Italy;
| | - Giovanna D’Arcangelo
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (M.M.); (A.M.R.); (G.D.); (V.T.)
- Center of Space Biomedicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Giuseppe Novelli
- Department of Biomedicine and Prevention, Medical Genetics Section, University of Rome “Tor Vergata”, 00133 Rome, Italy; (V.V.V.); (G.N.)
- IRCCS Neuromed, Unit of Medical Genetics, Via Atinense 18, 86077 Pozzilli, Italy
| | - Augusto Orlandi
- Department of Biomedicine and Prevention, Anatomic Pathology Section, University of Rome “Tor Vergata”, 00133 Rome, Italy; (F.C.); (A.O.)
| | - Virginia Tancredi
- Department of Systems Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy; (M.M.); (A.M.R.); (G.D.); (V.T.)
- Center of Space Biomedicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Umberto Tarantino
- Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata”, 00133 Rome, Italy;
- Department of Orthopedics and Traumatology, PTV Foundation, 00133 Rome, Italy
| | - Annalisa Botta
- Department of Biomedicine and Prevention, Medical Genetics Section, University of Rome “Tor Vergata”, 00133 Rome, Italy; (V.V.V.); (G.N.)
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Zhu B, Xue F, Li G, Zhang C. CRYAB promotes osteogenic differentiation of human bone marrow stem cells via stabilizing β-catenin and promoting the Wnt signalling. Cell Prolif 2019; 53:e12709. [PMID: 31638302 PMCID: PMC6985673 DOI: 10.1111/cpr.12709] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/12/2019] [Accepted: 09/02/2019] [Indexed: 12/14/2022] Open
Abstract
Objectives The osteogenesis differentiation of human bone marrow stem cells (BMSCs) is essential for bone formation and bone homeostasis. In this study, we aim to elucidate novel molecular targets for bone metabolism diseases. Materials and methods The dataset GSE80614 which includes mRNA expression profile during BMSCs osteogenic differentiation was obtained from the GEO database (https://www.ncbi.nlm.nih.gov/geo/). The osteogenic differentiation of BMSCs was measured by ALP staining, AR staining and expression of osteogenic markers in vitro. For in vivo assay, we seeded BMSCs onto beta‐tricalcium phosphate (β‐TCP) and transplanted them into muscle pockets of nude mice. Luciferase assay, co‐immunoprecipitation assay and in vitro ubiquitination assay were carried out to investigate the molecular mechanism. Results We found that α‐B‐crystallin (CRYAB) expression was elevated during the process of BMSCs osteogenic differentiation. Further studies showed that upregulation of CRYAB significantly enhanced the osteogenic differentiation, while downregulation of CRYAB suppressed it. CRYAB regulated BMSCs osteogenic differentiation mainly through the canonical Wnt/β‐catenin signalling. In addition, we found that CRYAB could physically interact with β‐catenin and protect it from ubiquitination and degradation, which stabilized β‐catenin and promoted the Wnt signalling. Conclusions The present study provides evidences that CRYAB is an important regulator of BMSCs osteogenic differentiation by protecting β‐catenin from ubiquitination and degradation and promoting the Wnt signalling. It may serve as a potential therapeutic target for diseases related to bone metabolism.
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Affiliation(s)
- Bin Zhu
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Feng Xue
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Guangyi Li
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Changqing Zhang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
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11
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Zhu B, Xue F, Zhang C, Li G. LMCD1 promotes osteogenic differentiation of human bone marrow stem cells by regulating BMP signaling. Cell Death Dis 2019; 10:647. [PMID: 31501411 PMCID: PMC6733937 DOI: 10.1038/s41419-019-1876-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/24/2019] [Accepted: 08/01/2019] [Indexed: 12/16/2022]
Abstract
Human bone marrow stem cells (BMSCs) are heterogeneous progenitor cells with two defining features, self-renew and multi-lineage differentiation. As one of the differentiation directions, osteogenesis is vital for bone homeostasis. A growing body of evidences show that ubiquitin-dependent protein degradation plays an essential role in the osteogenic differentiation of BMSCs. In this study, we found that LMCD1 was upregulated during osteogenic differentiation process of BMSCs by analyzing GSE80614. In vitro and in vivo functional studies confirmed that LMCD1 was critical to the osteogenic commitment of BMSCs. Compared to those of the controls, downregulation of LMCD1 significantly restrained osteogenic differentiation and enhanced adipogenic differentiation, while upregulation of LMCD1 increased the osteogenic differentiation and suppressed adipogenic differentiation. Mechanically, we found that LMCD1 could protect RUNX2 and Smad1 protein from Smurf1-induced ubiquitination degradation thereby regulating BMP signaling. In conclusion, our findings suggest that LMCD1 is a novel regulator of osteogenic differentiation and may be a potential therapeutic target for bone metabolism related diseases.
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Affiliation(s)
- Bin Zhu
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, NO.600 Yishan Road, 200233, Shanghai, China
| | - Feng Xue
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, NO.600 Yishan Road, 200233, Shanghai, China
| | - Changqing Zhang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, NO.600 Yishan Road, 200233, Shanghai, China.
| | - Guangyi Li
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, NO.600 Yishan Road, 200233, Shanghai, China.
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12
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Tan Y, Liu L. Prediction of pivotal pathways and hub genes associated with osteoporosis by Gibbs sampling. Exp Ther Med 2019; 17:2107-2112. [PMID: 30867698 PMCID: PMC6395965 DOI: 10.3892/etm.2019.7180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 01/03/2019] [Indexed: 11/06/2022] Open
Abstract
Osteoporosis (OP) is a common metabolic bone disease with high incidence, and is recognized as a major public health problem worldwide. It is essential to clarify the pathogenesis of the disease for improving the diagnosis, prevention and treatment of OP. The aim of this study was to clarify the pivotal pathways and hub genes in OP using Gibbs sampling. The gene expression profile datasets were obtained from Gene Expression Omnibus (GEO) database. The pathways were enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG) with genes intersection ≥5 based on gene expression profile data. Then, the acquired pathways were converted into Markov chains (MC). Gibbs sampling was conducted to obtain a new MC. In addition, the average probabilities of each pathway in two states containing human mesenchymal stem cells (hMSC) _middle-aged and hMSC_elderly were calculated through Markov chain Monte Carlo (MCMC) algorithm. Moreover, gene expression variation was taken into account to adjust the probability. Pivotal pathways were identified under adjusted posterior value >0.8. Then, Gibbs sampling was implemented to find hub genes from pathways. There were 280 pathways determined by the gene intersection ≥5. Gibbs sampling identified two disturbed pathways (pathways in cancer and influenza A) and two hub genes (cyclin A1 and WNT2) under the adjusted probability >0.8. Gene expression analysis showed that all the disturbed pathways and hub genes had increased expression levels in hMSC_middle-aged samples compared with hMSC_elderly samples. We identified two pivotal pathways and two hub genes in OP using Gibbs sampling. The results contribute to the understanding of underlying pathogenesis and could be considered as potential biomarkers for the therapy of OP.
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Affiliation(s)
- Yiyun Tan
- Department of Spinal Surgery, Changsha Hospital of Traditional Chinese Medicine (Changsha Eighth Hospital), Changsha, Hunan 410000, P.R. China
| | - Lei Liu
- Department of Pain, Qianfo Shan Hospital, Jinan, Shandong 250014, P.R. China
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13
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Baal N, Cunningham S, Obermann HL, Thomas J, Lippitsch A, Dietert K, Gruber AD, Kaufmann A, Michel G, Nist A, Stiewe T, Rupp O, Goesmann A, Zukunft S, Fleming I, Bein G, Lohmeyer J, Bauer S, Hackstein H. ADAR1 Is Required for Dendritic Cell Subset Homeostasis and Alveolar Macrophage Function. THE JOURNAL OF IMMUNOLOGY 2019; 202:1099-1111. [DOI: 10.4049/jimmunol.1800269] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 12/07/2018] [Indexed: 11/19/2022]
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14
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Wang C, Zou J, Ma X, Wang E, Peng G. Mechanisms and implications of ADAR-mediated RNA editing in cancer. Cancer Lett 2017; 411:27-34. [PMID: 28974449 DOI: 10.1016/j.canlet.2017.09.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 12/11/2022]
Abstract
Adenosine deaminases acting on RNA (ADARs) are enzymes that catalyze the conversion of adenosine (A) to inosine (I) in double-stranded RNAs. Inosine exhibits similar properties as guanosine. As a result, A-to-I editing has a great impact on edited RNAs, not only affecting the base pairing properties, but also altering codons after translation. A-to-I editing are known to mediate and diversify transcripts. However, the overall biological effect of ADARs are still largely unknown. Aberrant ADAR activity and editing dysregulation are present in a variety of cancers, including hepatocellular carcinoma, chronic myelogenous leukemia, glioblastoma and melanoma. ADAR-mediated A-to-I editing can influence uncontrolled nucleotide changes, resulting in susceptibility of cells to developmental defects and potential carcinogenicity. A deeper understanding of the biological function of ADARs may provide mechanistic insights in the development of new cancer therapy. Here, we discuss recent advances in research on ADAR in detail including the structure and function of ADARs, the biochemistry of ADAR-mediated RNA editing, and the relevance of ADAR proteins in cancer.
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Affiliation(s)
- Chen Wang
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jun Zou
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiangyi Ma
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Edward Wang
- OncoMed Pharmaceuticals, Redwood City, CA 94063, USA
| | - Guang Peng
- Department of Clinical Cancer Prevention, MD Anderson Cancer Center, The University of Texas, Houston, TX 77030, USA.
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15
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Protein recoding by ADAR1-mediated RNA editing is not essential for normal development and homeostasis. Genome Biol 2017; 18:166. [PMID: 28874170 PMCID: PMC5585977 DOI: 10.1186/s13059-017-1301-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 08/15/2017] [Indexed: 02/07/2023] Open
Abstract
Background Adenosine-to-inosine (A-to-I) editing of dsRNA by ADAR proteins is a pervasive epitranscriptome feature. Tens of thousands of A-to-I editing events are defined in the mouse, yet the functional impact of most is unknown. Editing causing protein recoding is the essential function of ADAR2, but an essential role for recoding by ADAR1 has not been demonstrated. ADAR1 has been proposed to have editing-dependent and editing-independent functions. The relative contribution of these in vivo has not been clearly defined. A critical function of ADAR1 is editing of endogenous RNA to prevent activation of the dsRNA sensor MDA5 (Ifih1). Outside of this, how ADAR1 editing contributes to normal development and homeostasis is uncertain. Results We describe the consequences of ADAR1 editing deficiency on murine homeostasis. Adar1E861A/E861AIfih1-/- mice are strikingly normal, including their lifespan. There is a mild, non-pathogenic innate immune activation signature in the Adar1E861A/E861AIfih1-/- mice. Assessing A-to-I editing across adult tissues demonstrates that outside of the brain, ADAR1 performs the majority of editing and that ADAR2 cannot compensate in its absence. Direct comparison of the Adar1-/- and Adar1E861A/E861A alleles demonstrates a high degree of concordance on both Ifih1+/+ and Ifih1-/- backgrounds, suggesting no substantial contribution from ADAR1 editing-independent functions. Conclusions These analyses demonstrate that the lifetime absence of ADAR1-editing is well tolerated in the absence of MDA5. We conclude that protein recoding arising from ADAR1-mediated editing is not essential for organismal homeostasis. Additionally, the phenotypes associated with loss of ADAR1 are the result of RNA editing and MDA5-dependent functions. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1301-4) contains supplementary material, which is available to authorized users.
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16
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RNA Editing, ADAR1, and the Innate Immune Response. Genes (Basel) 2017; 8:genes8010041. [PMID: 28106799 PMCID: PMC5295035 DOI: 10.3390/genes8010041] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/03/2017] [Accepted: 01/11/2017] [Indexed: 01/14/2023] Open
Abstract
RNA editing, particularly A-to-I RNA editing, has been shown to play an essential role in mammalian embryonic development and tissue homeostasis, and is implicated in the pathogenesis of many diseases including skin pigmentation disorder, autoimmune and inflammatory tissue injury, neuron degeneration, and various malignancies. A-to-I RNA editing is carried out by a small group of enzymes, the adenosine deaminase acting on RNAs (ADARs). Only three members of this protein family, ADAR1-3, exist in mammalian cells. ADAR3 is a catalytically null enzyme and the most significant function of ADAR2 was found to be in editing on the neuron receptor GluR-B mRNA. ADAR1, however, has been shown to play more significant roles in biological and pathological conditions. Although there remains much that is not known about how ADAR1 regulates cellular function, recent findings point to regulation of the innate immune response as an important function of ADAR1. Without appropriate RNA editing by ADAR1, endogenous RNA transcripts stimulate cytosolic RNA sensing receptors and therefore activate the IFN-inducing signaling pathways. Overactivation of innate immune pathways can lead to tissue injury and dysfunction. However, obvious gaps in our knowledge persist as to how ADAR1 regulates innate immune responses through RNA editing. Here, we review critical findings from ADAR1 mechanistic studies focusing on its regulatory function in innate immune responses and identify some of the important unanswered questions in the field.
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17
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Li S, Xu W, Xing Z, Qian J, Chen L, Gu R, Guo W, Lai X, Zhao W, Li S, Wang Y, Wang QJ, Deng F. A Conditional Knockout Mouse Model Reveals a Critical Role of PKD1 in Osteoblast Differentiation and Bone Development. Sci Rep 2017; 7:40505. [PMID: 28084409 PMCID: PMC5233966 DOI: 10.1038/srep40505] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 12/07/2016] [Indexed: 12/13/2022] Open
Abstract
The protein kinase D family of serine/threonine kinases, particularly PKD1, has been implicated in the regulation of a complex array of fundamental biological processes. However, its function and mechanism underlying PKD1-mediated the bone development and osteoblast differentiation are not fully understood. Here we demonstrate that loss of PKD1 function led to impaired bone development and osteoblast differentiation through STAT3 and p38 MAPK signaling using in vitro and in vivo bone-specific conditional PKD1-knockout (PKD1-KO) mice models. These mice developed markedly craniofacial dysplasia, scapula dysplasia, long bone length shortage and body weight decrease compared with wild-type littermates. Moreover, deletion of PKD1 in vivo reduced trabecular development and activity of osteoblast development, confirmed by Micro-CT and histological staining as well as expression of osteoblastic marker (OPN, Runx2 and OSX). Mechanistically, loss of PKD1 mediated the downregulation of osteoblast markers and impaired osteoblast differentiation through STAT3 and p38 MAPK signaling pathways. Taken together, these results demonstrated that PKD1 contributes to the osteoblast differentiation and bone development via elevation of osteoblast markers through activation of STAT3 and p38 MAPK signaling pathways.
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Affiliation(s)
- Shao Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Wanfu Xu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Zhe Xing
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Jiabi Qian
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Liping Chen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Ruonan Gu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Wenjing Guo
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Xiaoju Lai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Wanlu Zhao
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Songyu Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Yaodong Wang
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
| | - Q Jane Wang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Fan Deng
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, P. R. China
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18
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Liddicoat BJ, Hartner JC, Piskol R, Ramaswami G, Chalk AM, Kingsley PD, Sankaran VG, Wall M, Purton LE, Seeburg PH, Palis J, Orkin SH, Lu J, Li JB, Walkley CR. Adenosine-to-inosine RNA editing by ADAR1 is essential for normal murine erythropoiesis. Exp Hematol 2016; 44:947-63. [PMID: 27373493 DOI: 10.1016/j.exphem.2016.06.250] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 06/02/2016] [Indexed: 11/17/2022]
Abstract
Adenosine deaminases that act on RNA (ADARs) convert adenosine residues to inosine in double-stranded RNA. In vivo, ADAR1 is essential for the maintenance of hematopoietic stem/progenitors. Whether other hematopoietic cell types also require ADAR1 has not been assessed. Using erythroid- and myeloid-restricted deletion of Adar1, we demonstrate that ADAR1 is dispensable for myelopoiesis but is essential for normal erythropoiesis. Adar1-deficient erythroid cells display a profound activation of innate immune signaling and high levels of cell death. No changes in microRNA levels were found in ADAR1-deficient erythroid cells. Using an editing-deficient allele, we demonstrate that RNA editing is the essential function of ADAR1 during erythropoiesis. Mapping of adenosine-to-inosine editing in purified erythroid cells identified clusters of hyperedited adenosines located in long 3'-untranslated regions of erythroid-specific transcripts and these are ADAR1-specific editing events. ADAR1-mediated RNA editing is essential for normal erythropoiesis.
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Affiliation(s)
- Brian J Liddicoat
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Jochen C Hartner
- Taconic Biosciences, Cologne, Germany; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Division of Hematology/Oncology and Stem Cell Program, Children's Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Robert Piskol
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Gokul Ramaswami
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Alistair M Chalk
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Paul D Kingsley
- Center for Pediatric Biomedical Research, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Vijay G Sankaran
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Division of Hematology/Oncology and Stem Cell Program, Children's Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Meaghan Wall
- Victorian Cancer Cytogenetics Service, St. Vincent's Hospital, Fitzroy, Victoria, Australia
| | - Louise E Purton
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Peter H Seeburg
- Department of Molecular Neurobiology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - James Palis
- Center for Pediatric Biomedical Research, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Stuart H Orkin
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Division of Hematology/Oncology and Stem Cell Program, Children's Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA; Howard Hughes Medical Institute, Boston, MA, USA
| | - Jun Lu
- Department of Genetics and Yale Stem Cell Center, Yale University, New Haven, CT, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Carl R Walkley
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia.
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19
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Miftakhova R, Hedblom A, Batkiewicz L, Anagnosaki L, Zhang Y, Sjölander A, Wingren AG, Wolgemuth DJ, Persson JL. Cyclin A1 regulates the interactions between mouse haematopoietic stem and progenitor cells and their niches. Cell Cycle 2016; 14:1948-60. [PMID: 25785996 DOI: 10.1080/15384101.2015.1026513] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
It remains poorly understood how the haematopoietic stem/progenitor cells (HSPC) are attracted to their niches and the functional consequences of such interaction. In the present study, we show that the cell cycle regulator cyclin A1 in association with vascular endothelial growth factor receptor 1 (VEGFR1), is required for HSPC and their niches to maintain their function and proper interaction. In the absence of cyclin A1, the HSPC in the BM are increased in their frequency and display an increased migratory and homing ability. Concomitantly, the ability of the endosteal and central BM niche zones to attract and home the wild-type HSPC is significantly reduced in cyclin A1-null mice as compared to the wild-type controls. The impaired proliferation and homing of HSPC in the BM of cyclin A1-null mice are attributed to the increased density of microvessels in the endosteal and central BM niche zones, which is associated with the increased VEGFR1 expression. Thus, modulation of cyclin A1 and VEGFR1 in HSPC and their niches may provide new insights into therapeutic approaches.
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Affiliation(s)
- Regina Miftakhova
- a Division of Experimental Cancer Research; Department of Translational Medicine; Clinical Research Center; Lund University ; Malmö , Sweden
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20
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The role of RNA editing by ADAR1 in prevention of innate immune sensing of self-RNA. J Mol Med (Berl) 2016; 94:1095-1102. [PMID: 27044320 DOI: 10.1007/s00109-016-1416-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 03/16/2016] [Accepted: 03/24/2016] [Indexed: 12/25/2022]
Abstract
The innate immune system is the first line of the cellular defence against invading pathogens. A critical component of this defence is the capacity to discriminate foreign RNA molecules, which are distinct from most cellular RNAs in structure and/or modifications. However, a series of rare autoimmune/autoinflammatory diseases in humans highlight the propensity for the innate immune sensing system to be activated by endogenous cellular double-stranded RNAs (dsRNAs), underscoring the fine line between distinguishing self from non-self. The RNA editing enzyme ADAR1 has recently emerged as a key regulator that prevents innate immune pathway activation, principally the cytosolic dsRNA sensor MDA5, from inducing interferon in response to double-stranded RNA structures within endogenous RNAs. Adenosine-to-Inosine RNA editing by ADAR1 is proposed to destabilise duplexes formed from inverted repetitive elements within RNAs, which appear to prevent MDA5 from sensing these RNA as virus-like in the cytoplasm. Aberrant activation of these pathways has catastrophic effects at both a cellular and organismal level, contributing to one of the causes of the conditions collectively known as the type I interferonopathies.
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21
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Liddicoat BJ, Chalk AM, Walkley CR. ADAR1, inosine and the immune sensing system: distinguishing self from non-self. WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 7:157-72. [PMID: 26692549 DOI: 10.1002/wrna.1322] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/09/2015] [Accepted: 11/10/2015] [Indexed: 11/10/2022]
Abstract
The conversion of genomically encoded adenosine to inosine in dsRNA is termed as A-to-I RNA editing. This process is catalyzed by two of the three mammalian ADAR proteins (ADAR1 and ADAR2) both of which have essential functions for normal organismal homeostasis. The phenotype of ADAR2 deficiency can be primarily ascribed to a lack of site-selective editing of a single transcript in the brain. In contrast, the biology and substrates responsible for the Adar1(-/-) phenotype have remained more elusive. Several recent studies have identified that a feature of absence or reductions of ADAR1 activity, conserved across human and mouse models, is a profound activation of interferon-stimulated gene signatures and innate immune responses. Further analysis of this observation has lead to the conclusion that editing by ADAR1 is required to prevent activation of the cytosolic innate immune system, primarily focused on the dsRNA sensor MDA5 and leading to downstream signaling via MAVS. The delineation of this mechanism places ADAR1 at the interface between the cells ability to differentiate self- from non-self dsRNA. Based on MDA5 dsRNA recognition requisites, the mechanism indicates that the type of dsRNA must fulfil a particular structural characteristic, rather than a sequence-specific requirement. While additional studies are required to molecularly verify the genetic model, the observations to date collectively identify A-to-I editing by ADAR1 as a key modifier of the cellular response to endogenous dsRNA.
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Affiliation(s)
- Brian J Liddicoat
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Alistair M Chalk
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Carl R Walkley
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
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22
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AP2 suppresses osteoblast differentiation and mineralization through down-regulation of Frizzled-1. Biochem J 2015; 465:395-404. [DOI: 10.1042/bj20140668] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AP2 is an important transcription factor in bone development. AP2 binds to the human Frizzled 1 (FZD1) promoter and down-regulates FZD1 expression in osteoblasts. In addition, AP2 negatively regulates osteoblast differentiation and mineralization in part through down-regulation of FZD1 expression.
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23
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Zheng L, Zhu K, Jiao H, Zhao Z, Zhang L, Liu M, Deng W, Chen D, Yao Z, Xiao G. PTHrP expression in human MDA-MB-231 breast cancer cells is critical for tumor growth and survival and osteoblast inhibition. Int J Biol Sci 2013; 9:830-41. [PMID: 23983616 PMCID: PMC3753447 DOI: 10.7150/ijbs.7039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 08/06/2013] [Indexed: 12/29/2022] Open
Abstract
This study examined the effects of parathyroid hormone-related protein (PTHrP) derived from human MDA-MB-231 breast cancer cells on the tumor growth and osteoblast inhibition. Results revealed that knocking down PTHrP expression in the breast cancer cells strikingly inhibited the formation of subcutaneous tumors in nude mice. PTHrP knockdown dramatically decreased the levels of cyclins D1 and A1 proteins and arrested the cell cycle progression at the G1 stage. PTHrP knockdown led to the cleavage of Caspase 8 and induced apoptosis of the tumor cells. Interestingly, knocking down PTHrP increased the levels of Beclin1 and LC3-II and promoted the formation of autophagosomes. Knocking down PTHrP expression significantly reduced the abilities of the breast cancer cells to inhibit osteoblast differentiation and bone formation in vitro and in vivo. Finally, we found that PTHrP activated its own expression through an autocrine mechanism in MDA-MB-231 cells. Collectively, these studies suggest that targeting PTHrP expression in the tumor cells could be a potential therapeutic strategy for breast cancers, especially those with skeletal metastases.
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Affiliation(s)
- Lu Zheng
- Department of Immunology, Key Laboratory of Educational Ministry of China, Tianjin Medical University, Tianjin 300070, China
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24
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Yu S, Zhu K, Lai Y, Zhao Z, Fan J, Im HJ, Chen D, Xiao G. atf4 promotes β-catenin expression and osteoblastic differentiation of bone marrow mesenchymal stem cells. Int J Biol Sci 2013; 9:256-66. [PMID: 23494915 PMCID: PMC3596711 DOI: 10.7150/ijbs.5898] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 02/21/2013] [Indexed: 12/31/2022] Open
Abstract
Bone marrow mesenchymal stem cells (MSCs) can differentiate into multiple cell types including osteoblasts. How this differentiation process is controlled, however, is not completely understood. Here we show that activating transcription factor 4 (ATF4) plays a critical role in promoting bone marrow MSC differentiation towards the osteoblast lineage. Ablation of the Atf4 gene blocked the formation of osteoprogenitors and inhibited osteoblast differentiation without affecting the expansion and formation of MSCs in bone marrow cultures. Loss of ATF4 dramatically reduced the level of β-catenin protein in MSCs in vitro and in osteoblasts/osteoprogenitors located on trabecular and calvarial surfaces. Loss of ATF4 did not decrease the expression of major canonical Wnt/β-catenin signaling components such as Wnt3a, Wnt7b, Wnt10b, Lrp5, and Lrp6 in MSCs. Furthermore, shRNA knockdown of ATF4 expression decreased the level of β-catenin protein in MC-4 preosteoblasts. In contrast, overexpression of ATF4 increased β-catenin protein levels in MC-4 cells. Finally, ATF4 and β-catenin formed a protein-protein complex in COS-7 cells coexpressing both factors or in MC-4 preosteoblastic cells. This study establishes a new role of ATF4 in controlling the β-catenin protein levels and MSC differentiation towards the osteoblast lineage.
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Affiliation(s)
- Shibing Yu
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15240, USA
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