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Nichtová Z, Fernandez-Sanz C, De La Fuente S, Yuan Y, Hurst S, Lanvermann S, Tsai HY, Weaver D, Baggett A, Thompson C, Bouchet-Marquis C, Várnai P, Seifert EL, Dorn GW, Sheu SS, Csordás G. Enhanced Mitochondria-SR Tethering Triggers Adaptive Cardiac Muscle Remodeling. Circ Res 2023; 132:e171-e187. [PMID: 37057625 PMCID: PMC10213149 DOI: 10.1161/circresaha.122.321833] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/29/2023] [Indexed: 04/15/2023]
Abstract
BACKGROUND Cardiac contractile function requires high energy from mitochondria, and Ca2+ from the sarcoplasmic reticulum (SR). Via local Ca2+ transfer at close mitochondria-SR contacts, cardiac excitation feedforward regulates mitochondrial ATP production to match surges in demand (excitation-bioenergetics coupling). However, pathological stresses may cause mitochondrial Ca2+ overload, excessive reactive oxygen species production and permeability transition, risking homeostatic collapse and myocyte loss. Excitation-bioenergetics coupling involves mitochondria-SR tethers but the role of tethering in cardiac physiology/pathology is debated. Endogenous tether proteins are multifunctional; therefore, nonselective targets to scrutinize interorganelle linkage. Here, we assessed the physiological/pathological relevance of selective chronic enhancement of cardiac mitochondria-SR tethering. METHODS We introduced to mice a cardiac muscle-specific engineered tether (linker) transgene with a fluorescent protein core and deployed 2D/3D electron microscopy, biochemical approaches, fluorescence imaging, in vivo and ex vivo cardiac performance monitoring and stress challenges to characterize the linker phenotype. RESULTS Expressed in the mature cardiomyocytes, the linker expanded and tightened individual mitochondria-junctional SR contacts; but also evoked a marked remodeling with large dense mitochondrial clusters that excluded dyads. Yet, excitation-bioenergetics coupling remained well-preserved, likely due to more longitudinal mitochondria-dyad contacts and nanotunnelling between mitochondria exposed to junctional SR and those sealed away from junctional SR. Remarkably, the linker decreased female vulnerability to acute massive β-adrenergic stress. It also reduced myocyte death and mitochondrial calcium-overload-associated myocardial impairment in ex vivo ischemia/reperfusion injury. CONCLUSIONS We propose that mitochondria-SR/endoplasmic reticulum contacts operate at a structural optimum. Although acute changes in tethering may cause dysfunction, upon chronic enhancement of contacts from early life, adaptive remodeling of the organelles shifts the system to a new, stable structural optimum. This remodeling balances the individually enhanced mitochondrion-junctional SR crosstalk and excitation-bioenergetics coupling, by increasing the connected mitochondrial pool and, presumably, Ca2+/reactive oxygen species capacity, which then improves the resilience to stresses associated with dysregulated hyperactive Ca2+ signaling.
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Affiliation(s)
- Zuzana Nichtová
- MitoCare, Pathology and Genomic Medicine, TJUH, Philadelphia, PA, USA
| | - Celia Fernandez-Sanz
- Center of Translational Medicine, TJUH, Philadelphia, PA, USA
- These authors contributed equally
| | - Sergio De La Fuente
- Center of Translational Medicine, TJUH, Philadelphia, PA, USA
- These authors contributed equally
| | - Yuexing Yuan
- Center of Translational Medicine, TJUH, Philadelphia, PA, USA
| | - Stephen Hurst
- MitoCare, Pathology and Genomic Medicine, TJUH, Philadelphia, PA, USA
| | | | - Hui-Ying Tsai
- Center of Translational Medicine, TJUH, Philadelphia, PA, USA
| | - David Weaver
- MitoCare, Pathology and Genomic Medicine, TJUH, Philadelphia, PA, USA
| | - Ariele Baggett
- MitoCare, Pathology and Genomic Medicine, TJUH, Philadelphia, PA, USA
| | | | | | - Péter Várnai
- Department of Physiology, Faculty of Medicine, Semmelweis Univ., Budapest, Hungary
| | - Erin L Seifert
- MitoCare, Pathology and Genomic Medicine, TJUH, Philadelphia, PA, USA
| | - Gerald W Dorn
- Center for Pharmacogenomics, John T. Milliken Dep. Med., WUSM, St Louis, MO, USA
| | - Shey-Shing Sheu
- Center of Translational Medicine, TJUH, Philadelphia, PA, USA
| | - György Csordás
- MitoCare, Pathology and Genomic Medicine, TJUH, Philadelphia, PA, USA
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Mercado-Ayón E, Warren N, Halawani S, Rodden LN, Ngaba L, Dong YN, Chang JC, Fonck C, Mavilio F, Lynch DR, Lin H. Cerebellar Pathology in an Inducible Mouse Model of Friedreich Ataxia. Front Neurosci 2022; 16:819569. [PMID: 35401081 PMCID: PMC8987918 DOI: 10.3389/fnins.2022.819569] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by deficiency of the mitochondrial protein frataxin. Lack of frataxin causes neuronal loss in various areas of the CNS and PNS. In particular, cerebellar neuropathology in FRDA patients includes loss of large principal neurons and synaptic terminals in the dentate nucleus (DN), and previous studies have demonstrated early synaptic deficits in the Knockin-Knockout mouse model of FRDA. However, the exact correlation of frataxin deficiency with cerebellar neuropathology remains unclear. Here we report that doxycycline-induced frataxin knockdown in a mouse model of FRDA (FRDAkd) leads to synaptic cerebellar degeneration that can be partially reversed by AAV8-mediated frataxin restoration. Loss of cerebellar Purkinje neurons and large DN principal neurons are observed in the FRDAkd mouse cerebellum. Levels of the climbing fiber-specific glutamatergic synaptic marker VGLUT2 decline starting at 4 weeks after dox induction, whereas levels of the parallel fiber-specific synaptic marker VGLUT1 are reduced by 18-weeks. These findings suggest initial selective degeneration of climbing fiber synapses followed by loss of parallel fiber synapses. The GABAergic synaptic marker GAD65 progressively declined during dox induction in FRDAkd mice, while GAD67 levels remained unaltered, suggesting specific roles for frataxin in maintaining cerebellar synaptic integrity and function during adulthood. Expression of frataxin following AAV8-mediated gene transfer partially restored VGLUT1/2 levels. Taken together, our findings show that frataxin knockdown leads to cerebellar degeneration in the FRDAkd mouse model, suggesting that frataxin helps maintain cerebellar structure and function.
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Affiliation(s)
- Elizabeth Mercado-Ayón
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Nathan Warren
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Sarah Halawani
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Layne N. Rodden
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Lucie Ngaba
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Yi Na Dong
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | | | - Carlos Fonck
- Audentes Therapeutics, San Francisco, CA, United States
| | - Fulvio Mavilio
- Audentes Therapeutics, San Francisco, CA, United States
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - David R. Lynch
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Department of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- *Correspondence: David R. Lynch, ;
| | - Hong Lin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Hong Lin,
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3
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Das AT, Tenenbaum L, Berkhout B. Tet-On Systems For Doxycycline-inducible Gene Expression. Curr Gene Ther 2017; 16:156-67. [PMID: 27216914 PMCID: PMC5070417 DOI: 10.2174/1566523216666160524144041] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/03/2016] [Accepted: 05/03/2016] [Indexed: 11/22/2022]
Abstract
The tetracycline-controlled Tet-Off and Tet-On gene expression systems are used to regulate the activity of genes in eukaryotic cells in diverse settings, varying from basic biological research to biotechnology and gene therapy applications. These systems are based on regulatory elements that control the activity of the tetracycline-resistance operon in bacteria. The Tet-Off system allows silencing of gene expression by administration of tetracycline (Tc) or tetracycline-derivatives like doxycycline (dox), whereas the Tet-On system allows activation of gene expression by dox. Since the initial design and construction of the original Tet-system, these bacterium-derived systems have been significantly improved for their function in eukaryotic cells. We here review how a dox-controlled HIV-1 variant was designed and used to greatly improve the activity and dox-sensitivity of the rtTA transcriptional activator component of the Tet-On system. These optimized rtTA variants require less dox for activation, which will reduce side effects and allow gene control in tissues where a relatively low dox level can be reached, such as the brain.
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Affiliation(s)
- Atze T Das
- Laboratory of Experimental Virology, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
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4
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Anders K, Kershaw O, Larue L, Gruber AD, Blankenstein T. The immune system prevents recurrence of transplanted but not autochthonous antigenic tumors after oncogene inactivation therapy. Int J Cancer 2017; 141:2551-2561. [PMID: 28833076 DOI: 10.1002/ijc.31009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/11/2017] [Accepted: 08/15/2017] [Indexed: 12/22/2022]
Abstract
Targeted oncogene inactivation by small molecule inhibitors can be very effective but tumor recurrence is a frequent problem in the clinic. Therapy by inactivation of the cancer-driving oncogene in transplanted tumors was shown to be augmented in the presence of T cells. However, these experiments did not take into account the long-term, usually tolerogenic, interaction of de novo malignancies with the immune system. Here, we employed mice, in which SV40 large T (Tag) and firefly luciferase (Luc) as fusion protein (TagLuc) could be regulated with the Tet-on system and upon activation resulted in tumors after a long latency. TagLuc inactivation induced profound tumor regression, demonstrating sustained oncogene addiction. While tumor relapse after TagLuc inactivation was prevented in immunocompetent mice bearing transplanted tumors, autochthonous tumors relapsed or recurred after therapy discontinuation indicating that the immune system that coevolved with the malignancy over an extended period of time lost the potency to mount an efficient anti-tumor immune response. By contrast, adoptively transferred CD8+ T cells targeting the cancer-driving oncogene eradicated recurrent autochthonous tumors, highlighting a suitable therapy option in a clinically relevant model.
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Affiliation(s)
| | | | - Lionel Larue
- Normal and Pathological Development of Melanocytes, 91405 Orsay, France.,Centre National de la Recherche Scientifique (CNRS) UMR3347, 91405 Orsay, France.,INSERM U1021, 91405 Orsay, France.,Equipe Labellisee e Ligue Nationale contre le Cancer, 91405 Orsay, France
| | | | - Thomas Blankenstein
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.,Institute of Immunology, Charité Campus Berlin Buch, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
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5
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Textor A, Schmidt K, Kloetzel PM, Weißbrich B, Perez C, Charo J, Anders K, Sidney J, Sette A, Schumacher TNM, Keller C, Busch DH, Seifert U, Blankenstein T. Preventing tumor escape by targeting a post-proteasomal trimming independent epitope. J Exp Med 2016; 213:2333-2348. [PMID: 27697836 PMCID: PMC5068242 DOI: 10.1084/jem.20160636] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/31/2016] [Indexed: 02/05/2023] Open
Abstract
Blankenstein and colleagues describe a novel strategy to avoid tumor escape from adoptive T cell therapy. Adoptive T cell therapy (ATT) can achieve regression of large tumors in mice and humans; however, tumors frequently recur. High target peptide-major histocompatibility complex-I (pMHC) affinity and T cell receptor (TCR)-pMHC affinity are thought to be critical to preventing relapse. Here, we show that targeting two epitopes of the same antigen in the same cancer cells via monospecific T cells, which have similar pMHC and pMHC-TCR affinity, results in eradication of large, established tumors when targeting the apparently subdominant but not the dominant epitope. Only the escape but not the rejection epitope required postproteasomal trimming, which was regulated by IFN-γ, allowing IFN-γ–unresponsive cancer variants to evade. The data describe a novel immune escape mechanism and better define suitable target epitopes for ATT.
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Affiliation(s)
- Ana Textor
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | - Karin Schmidt
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany.,Institute for Biochemistry, Charité, Campus Mitte, 10117 Berlin, Germany
| | - Peter-M Kloetzel
- Institute for Biochemistry, Charité, Campus Mitte, 10117 Berlin, Germany.,Berlin Institute of Health, 10117 Berlin, Germany
| | - Bianca Weißbrich
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University, 81675 Munich, Germany
| | - Cynthia Perez
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | - Jehad Charo
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | - Kathleen Anders
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany
| | - John Sidney
- La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Alessandro Sette
- La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Ton N M Schumacher
- The Division of Immunology, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Christin Keller
- Institute for Biochemistry, Charité, Campus Mitte, 10117 Berlin, Germany
| | - Dirk H Busch
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University, 81675 Munich, Germany
| | - Ulrike Seifert
- Institute for Biochemistry, Charité, Campus Mitte, 10117 Berlin, Germany.,Institute for Molecular and Clinical Immunology, Otto-von-Guericke-Universität, 39120 Magdeburg, Germany.,Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Thomas Blankenstein
- Max-Delbrück-Center for Molecular Medicine, 13125 Berlin, Germany .,Berlin Institute of Health, 10117 Berlin, Germany.,Institute of Immunology, Charité, Campus Buch, 13125 Berlin, Germany
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6
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Ma Y, Li J, Yao Y, Wei D, Wang R, Wu Q. A controlled double-duration inducible gene expression system for cartilage tissue engineering. Sci Rep 2016; 6:26617. [PMID: 27222430 PMCID: PMC4879534 DOI: 10.1038/srep26617] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 05/04/2016] [Indexed: 02/08/2023] Open
Abstract
Cartilage engineering that combines competent seeding cells and a compatible scaffold is increasingly gaining popularity and is potentially useful for the treatment of various bone and cartilage diseases. Intensive efforts have been made by researchers to improve the viability and functionality of seeding cells of engineered constructs that are implanted into damaged cartilage. Here, we designed an integrative system combining gene engineering and the controlled-release concept to solve the problems of both seeding cell viability and functionality through precisely regulating the anti-apoptotic gene bcl-2 in the short-term and the chondrogenic master regulator Sox9 in the long-term. Both in vitro and in vivo experiments demonstrated that our system enhances the cell viability and chondrogenic effects of the engineered scaffold after introduction of the system while restricting anti-apoptotic gene expression to only the early stage, thereby preventing potential oncogenic and overdose effects. Our system was designed to be modular and can also be readily adapted to other tissue engineering applications with minor modification.
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Affiliation(s)
- Ying Ma
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic &System Biology, Tsinghua University, Beijing, China
| | - Junxiang Li
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic &System Biology, Tsinghua University, Beijing, China
| | - Yi Yao
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic &System Biology, Tsinghua University, Beijing, China
| | - Daixu Wei
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic &System Biology, Tsinghua University, Beijing, China
| | - Rui Wang
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic &System Biology, Tsinghua University, Beijing, China
| | - Qiong Wu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,Center for Synthetic &System Biology, Tsinghua University, Beijing, China
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7
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Leitner NR, Lassnig C, Rom R, Heider S, Bago-Horvath Z, Eferl R, Müller S, Kolbe T, Kenner L, Rülicke T, Strobl B, Müller M. Inducible, dose-adjustable and time-restricted reconstitution of STAT1 deficiency in vivo. PLoS One 2014; 9:e86608. [PMID: 24489749 PMCID: PMC3906053 DOI: 10.1371/journal.pone.0086608] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/11/2013] [Indexed: 12/31/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) 1 is a key player in interferon (IFN) signaling, essential in mediating host defense against viruses and other pathogens. STAT1 levels are tightly regulated and loss- or gain-of-function mutations in mice and men lead to severe diseases. We have generated a doxycycline (dox) -inducible, FLAG-tagged Stat1 expression system in mice lacking endogenous STAT1 (i.e. Stat1ind mice). We show that STAT1 expression depends on the time and dose of dox treatment in primary cells and a variety of organs isolated from Stat1ind mice. In bone marrow-derived macrophages, a fraction of the amount of STAT1 present in WT cells is sufficient for full expression of IFN-induced genes. Dox-induced STAT1 established protection against virus infections in primary cells and mice. The availability of the Stat1ind mouse model will enable an examination of the consequences of variable amounts of STAT1. The model will also permit the study of STAT1 dose-dependent and reversible functions as well as of STAT1's contributions to the development, progression and resolution of disease.
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Affiliation(s)
- Nicole R. Leitner
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- * E-mail: (NRL); (MM)
| | - Caroline Lassnig
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- University Center Biomodels Austria (BIAT), University of Veterinary Medicine Vienna, Vienna, Austria
| | - Rita Rom
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Susanne Heider
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
| | - Zsuzsanna Bago-Horvath
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Robert Eferl
- Department of Internal Medicine I, Institute for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Simone Müller
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Thomas Kolbe
- University Center Biomodels Austria (BIAT), University of Veterinary Medicine Vienna, Vienna, Austria
- Department IFA-Tulln, Biotechnology in Animal Production, University of Natural Resources and Applied Life Sciences, Tulln, Austria
| | - Lukas Kenner
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
| | - Thomas Rülicke
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Birgit Strobl
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Mathias Müller
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
- University Center Biomodels Austria (BIAT), University of Veterinary Medicine Vienna, Vienna, Austria
- * E-mail: (NRL); (MM)
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8
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Yao Y, He Y, Guan Q, Wu Q. A tetracycline expression system in combination with Sox9 for cartilage tissue engineering. Biomaterials 2013; 35:1898-906. [PMID: 24321708 DOI: 10.1016/j.biomaterials.2013.11.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 11/18/2013] [Indexed: 01/28/2023]
Abstract
Cartilage tissue engineering using controllable transcriptional therapy together with synthetic biopolymer scaffolds shows higher potential for overcoming chondrocyte degradation and constructing artificial cartilages both in vivo and in vitro. Here, the potential regulating tetracycline expression (Tet-on) system was used to express Sox9 both in vivo and in vitro. Chondrocyte degradation was measured in vitro and overcome by Soxf9 expression. Experiments confirmed the feasibility of the combined use of Sox9 and Tet-on system in cartilage tissue engineering. Engineered poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) scaffolds were seeded with recombinant chondrocytes which were transfected with Tet-induced Sox9 expression; the scaffolds were implanted under the skin of 8-week-old rats. The experimental group was injected with Dox in the abdomen, while the control group was injected with normal saline. After 4 or 8 days of implantation in vivo, the newly formed pieces of articular chondrocytes were taken out and measured. Dox injection in vivo showed positive effect on recombinant chondrocytes, in which Sox9 expression was up-regulated by an inducible system with specific matrix proteins. The results demonstrate this controllable transcriptional therapy is a potential approach for tissue engineering.
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Affiliation(s)
- Yi Yao
- MOE Key Lab. Bioinformatics, Center for Epigentics and Chromatin, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yu He
- MOE Key Lab. Bioinformatics, Center for Epigentics and Chromatin, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qian Guan
- MOE Key Lab. Bioinformatics, Center for Epigentics and Chromatin, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiong Wu
- MOE Key Lab. Bioinformatics, Center for Epigentics and Chromatin, School of Life Sciences, Tsinghua University, Beijing 100084, China.
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9
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Sargeant TJ, Drage DJ, Wang S, Apostolakis AA, Cox TM, Cachón-González MB. Characterization of inducible models of Tay-Sachs and related disease. PLoS Genet 2012; 8:e1002943. [PMID: 23028353 PMCID: PMC3447966 DOI: 10.1371/journal.pgen.1002943] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 07/25/2012] [Indexed: 11/18/2022] Open
Abstract
Tay-Sachs and Sandhoff diseases are lethal inborn errors of acid β-N-acetylhexosaminidase activity, characterized by lysosomal storage of GM2 ganglioside and related glycoconjugates in the nervous system. The molecular events that lead to irreversible neuronal injury accompanied by gliosis are unknown; but gene transfer, when undertaken before neurological signs are manifest, effectively rescues the acute neurodegenerative illness in Hexb−/− (Sandhoff) mice that lack β-hexosaminidases A and B. To define determinants of therapeutic efficacy and establish a dynamic experimental platform to systematically investigate cellular pathogenesis of GM2 gangliosidosis, we generated two inducible experimental models. Reversible transgenic expression of β-hexosaminidase directed by two promoters, mouse Hexb and human Synapsin 1 promoters, permitted progression of GM2 gangliosidosis in Sandhoff mice to be modified at pre-defined ages. A single auto-regulatory tetracycline-sensitive expression cassette controlled expression of transgenic Hexb in the brain of Hexb−/− mice and provided long-term rescue from the acute neuronopathic disorder, as well as the accompanying pathological storage of glycoconjugates and gliosis in most parts of the brain. Ultimately, late-onset brainstem and ventral spinal cord pathology occurred and was associated with increased tone in the limbs. Silencing transgenic Hexb expression in five-week-old mice induced stereotypic signs and progression of Sandhoff disease, including tremor, bradykinesia, and hind-limb paralysis. As in germline Hexb−/− mice, these neurodegenerative manifestations advanced rapidly, indicating that the pathogenesis and progression of GM2 gangliosidosis is not influenced by developmental events in the maturing nervous system. Sandhoff and Tay-Sachs disease are devastating neurological diseases associated with developmental regression, blindness, seizures, and death in infants and young children. These disorders are caused by mutations in β-hexosaminidase genes, which result in neuronal accumulation of certain lipids, glycosphingolipids, inside the lysosomes of neurons. It is not yet known how accumulation of lipids affects neuronal function, and although promising treatments such as gene therapy are in development, currently none has been clinically approved. We aimed to develop genetic models that allow manipulation of β-hexosaminidase expression over time. Two inducible strains of mice were created in which acute Sandhoff disease could be “turned on” by the addition of doxycycline in the diet. Once induced in the adult mouse, the disease progressed relentlessly and was apparently independent of the rapid developmental processes that occur in the fetal and neonatal brain, resembling disease course in the germline Hexb−/− mouse. These transgenic inducible strains of Sandhoff disease mice provide a dynamic platform with which to explore the pathophysiological sequelae immediately after loss of neuronal lysosomal β-hexosaminidase activity.
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Affiliation(s)
- Timothy J Sargeant
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom.
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