bims-algemi Biomed News
on Allotopic expression and gene therapy for mitochondrial disease
Issue of 2020‒03‒01
twenty papers selected by
Atif Towheed
Columbia University Irving Medical Center

  1. J Intern Med. 2020 Feb 25.
    Viscomi C, Zeviani M.
      Mitochondrial diseases are extremely heterogeneous genetic conditions characterized by faulty oxidative phosphorylation (OxPhos). OxPhos deficiency can be the result of mutation in mtDNA genes, encoding either proteins (13 subunits of the mitochondrial complexes I, III, IV and V) or the tRNA and rRNA components of the in situ mtDNA translation. The remaining mitochondrial disease genes are in the nucleus, encoding proteins with a huge variety of functions, from structural subunits of the mitochondrial complexes, to factors involved in their formation and regulation, components of the mtDNA replication and expression machinery, biosynthetic enzymes for the biosynthesis or incorporation of prosthetic groups, components of the mitochondrial quality control and proteostasis, enzymes involved in the clearance of toxic compounds, factors involved in the formation of the lipid milieu, etc. These different functions represent potential targets for "general" therapeutic interventions, as they may be adapted to a number of different mitochondrial conditions. This is in contrast with "tailored", personalized therapeutic approaches, such as gene therapy, cell therapy and organ replacement, that can be useful only for individual conditions. This review will present the most recent concepts emerged from preclinical work and the attempts to translate them into the clinics. The common notion that mitochondrial disorders have no cure is currently challenged by a massive effort of scientists and clinicians, and we do expect that thanks to this intensive investigation work, tangible results for the development of strategies amenable to the treatment of patients with these tremendously difficult conditions are not so far away.
  2. J Cell Mol Med. 2020 Feb 25.
    Jacinto FV, Link W, Ferreira BI.
      The recent development of the CRISPR/Cas9 system as an efficient and accessible programmable genome-editing tool has revolutionized basic science research. CRISPR/Cas9 system-based technologies have armed researchers with new powerful tools to unveil the impact of genetics on disease development by enabling the creation of precise cellular and animal models of human diseases. The therapeutic potential of these technologies is tremendous, particularly in gene therapy, in which a patient-specific mutation is genetically corrected in order to treat human diseases that are untreatable with conventional therapies. However, the translation of CRISPR/Cas9 into the clinics will be challenging, since we still need to improve the efficiency, specificity and delivery of this technology. In this review, we focus on several in vitro, in vivo and ex vivo applications of the CRISPR/Cas9 system in human disease-focused research, explore the potential of this technology in translational medicine and discuss some of the major challenges for its future use in patients.
    Keywords:  CRISPR; gene therapy; genome editing; translational medicine
  3. Brain Sci. 2020 Feb 22. pii: E119. [Epub ahead of print]10(2):
    Perez BA, Shutterly A, Chan YK, Byrne BJ, Corti M.
      Recently, adeno-associated virus (AAV)-mediated gene therapies have attracted clinical interest for treating neurodegenerative diseases including spinal muscular atrophy (SMA), Canavan disease (CD), Parkinson's disease (PD), and Friedreich's ataxia (FA). The influx of clinical findings led to the first approved gene therapy for neurodegenerative disorders in 2019 and highlighted new safety concerns for patients. Large doses of systemically administered AAV stimulate host immune responses, resulting in anti-capsid and anti-transgene immunity with implications for transgene expression, treatment longevity, and patient safety. Delivering lower doses directly to the central nervous system (CNS) is a promising alternative, resulting in higher transgene expression with decreased immune responses. However, neuroinflammatory responses after CNS-targeted delivery of AAV are a critical concern. Reported signs of AAV-associated neuroinflammation in preclinical studies include dorsal root ganglion (DRG) and spinal cord pathology with mononuclear cell infiltration. In this review, we discuss ways to manage neuroinflammation, including choice of AAV capsid serotypes, CNS-targeting routes of delivery, genetic modifications to the vector and/or transgene, and adding immunosuppressive strategies to clinical protocols. As additional gene therapies for neurodegenerative diseases enter clinics, tracking biomarkers of neuroinflammation will be important for understanding the impact immune reactions can have on treatment safety and efficacy.
    Keywords:  AAV; gene therapy; immunosuppression; neurodegeneration; neuroinflammation
  4. Mol Ther Methods Clin Dev. 2020 Jun 12. 17 369-377
    Paulis M, Susani L, Castelli A, Suzuki T, Hara T, Straniero L, Duga S, Strina D, Mantero S, Caldana E, Sergi LS, Villa A, Vezzoni P.
      Many human genetic diseases are associated with gross mutations such as aneuploidies, deletions, duplications, or inversions. For these "structural" disorders, conventional gene therapy, based on viral vectors and/or on programmable nuclease-mediated homologous recombination, is still unsatisfactory. To correct such disorders, chromosome transplantation (CT), defined as the perfect substitution of an endogenous defective chromosome with an exogenous normal one, could be applied. CT re-establishes a normal diploid cell, leaving no marker of the procedure, as we have recently shown in mouse pluripotent stem cells. To prove the feasibility of the CT approach in human cells, we used human induced pluripotent stem cells (hiPSCs) reprogrammed from Lesch-Nyhan (LN) disease patients, taking advantage of their mutation in the X-linked HPRT gene, making the LN cells selectable and distinguishable from the resistant corrected normal cells. In this study, we demonstrate, for the first time, that CT is feasible in hiPSCs: the normal exogenous X chromosome was first transferred using an improved chromosome transfer system, and the extra sex chromosome was spontaneously lost. These CT cells were functionally corrected and maintained their pluripotency and differentiation capability. By inactivation of the autologous HPRT gene, CT paves the way to the correction of hiPSCs from several X-linked disorders.
    Keywords:  chromosome transfer; chromosome transplantation; genetic therapy; genomic disorders; induced pluripotent stem cells
  5. J Clin Med. 2020 Feb 21. pii: E589. [Epub ahead of print]9(2):
    Blanc F, Mondain M, Bemelmans AP, Affortit C, Puel JL, Wang J.
      Over the last decade, pioneering molecular gene therapy for inner-ear disorders have achieved experimental hearing improvements after a single local or systemic injection of adeno-associated, virus-derived vectors (rAAV for recombinant AAV) encoding an extra copy of a normal gene, or ribozymes used to modify a genome. These results hold promise for treating congenital or later-onset hearing loss resulting from monogenic disorders with gene therapy approaches in patients. In this review, we summarize the current state of rAAV-mediated inner-ear gene therapies including the choice of vectors and delivery routes, and discuss the prospects and obstacles for the future development of efficient clinical rAAV-mediated cochlear gene medicine therapy.
    Keywords:  RNAi; clinical application; cochlear gene therapy; gene editing; genetic deafness; rAAV; routes of delivery; serotypes; targets gene addition
  6. Nat Med. 2020 Feb 24.
    Cehajic-Kapetanovic J, Xue K, Martinez-Fernandez de la Camara C, Nanda A, Davies A, Wood LJ, Salvetti AP, Fischer MD, Aylward JW, Barnard AR, Jolly JK, Luo E, Lujan BJ, Ong T, Girach A, Black GCM, Gregori NZ, Davis JL, Rosa PR, Lotery AJ, Lam BL, Stanga PE, MacLaren RE.
      Retinal gene therapy has shown great promise in treating retinitis pigmentosa (RP), a primary photoreceptor degeneration that leads to severe sight loss in young people. In the present study, we report the first-in-human phase 1/2, dose-escalation clinical trial for X-linked RP caused by mutations in the RP GTPase regulator (RPGR) gene in 18 patients over up to 6 months of follow-up ( NCT03116113). The primary outcome of the study was safety, and secondary outcomes included visual acuity, microperimetry and central retinal thickness. Apart from steroid-responsive subretinal inflammation in patients at the higher doses, there were no notable safety concerns after subretinal delivery of an adeno-associated viral vector encoding codon-optimized human RPGR (AAV8-coRPGR), meeting the pre-specified primary endpoint. Visual field improvements beginning at 1 month and maintained to the last point of follow-up were observed in six patients.
  7. Biotechnol Adv. 2020 Feb 20. pii: S0734-9750(20)30031-8. [Epub ahead of print] 107534
    Weng Y, Li C, Yang T, Hu B, Zhang M, Guo S, Xiao H, Liang XJ, Huang Y.
      Messenger RNA (mRNA)-based therapeutics hold the potential to cause a major revolution in the pharmaceutical industry because they can be used for precise and individualized therapy, and enable patients to produce therapeutic proteins in their own bodies without struggling with the comprehensive manufacturing issues associated with recombinant proteins. Compared with the current therapeutics, the production of mRNA is much cost-effective, faster and more flexible because it can be easily produced by in vitro transcription, and the process is independent of mRNA sequence. Moreover, mRNA vaccines allow people to develop personalized medications based on sequencing results and/or personalized conditions rapidly. Along with the great potential from bench to bedside, technical obstacles facing mRNA pharmaceuticals are also obvious. The stability, immunogenicity, translation efficiency, and delivery are all pivotal issues need to be addressed. In the recently published research results, these issues are gradually being overcome by state-of-the-art development technologies. In this review, we describe the structural properties and modification technologies of mRNA, summarize the latest advances in developing mRNA delivery systems, review the preclinical and clinical applications, and put forward our views on the prospect and challenges of developing mRNA into a new class of drug.
  8. Circ Res. 2020 Feb 28. 126(5): 663-678
    Huang CK, Kafert-Kasting S, Thum T.
      RNA modulation has become a promising therapeutic approach for the treatment of several types of disease. The emerging field of noncoding RNA-based therapies has now come to the attention of cardiovascular research, in which it could provide valuable advancements in comparison to current pharmacotherapy such as small molecule drugs or antibodies. In this review, we focus on noncoding RNA-based studies conducted mainly in large-animal models, including pigs, rabbits, dogs, and nonhuman primates. The obstacles and promises of targeting long noncoding RNAs and circRNAs as therapeutic modalities in humans are specifically discussed. We also describe novel ex vivo methods based on human cells and tissues, such as engineered heart tissues and living myocardial slices that could help bridging the gap between in vivo models and clinical applications in the future. Finally, we summarize antisense oligonucleotide drugs that have already been approved by the Food and Drug Administration for targeting mRNAs and discuss the progress of noncoding RNA-based drugs in clinical trials. Additional factors, such as drug chemistry, drug formulations, different routes of administration, and the advantages of RNA-based drugs, are also included in the present review. Recently, first therapeutic miRNA-based inhibitory strategies have been tested in heart failure patients as well as healthy volunteers to study effects on wound healing (NCT04045405; NCT03603431). In summary, a combination of novel therapeutic RNA targets, large-animal models, ex vivo studies with human cells/tissues, and new delivery techniques will likely lead to significant progress in the development of noncoding RNA-based next-generation therapeutics for cardiovascular disease.
    Keywords:  animal models; cardiovascular diseases; nucleic acids; nucleosides; nucleotides; therapeutics
  9. Curr Eye Res. 2020 Feb 28.
    Zhao X, Zhang Y, Lu L, Yang H.
      Purpose: To characterize the potential therapeutic effects of idebenone on Leber hereditary optic neuropathy (LHON) in terms of visual acuity (VA), visual field (VF) defects, visual evoked potential (VEP) and retinal nerve fibre layer (RNFL) thickness using optical coherence tomography (OCT) measurements.Methods: This was a retrospective case-controlled study of the effect of idebenone (900 mg/d) on 30 patients with LHON due to m.3460G>A, m.11778G>A and m.14484T>C mutations. The primary end-point was the recovery in VA after 3 and 6 mon. The main secondary end-point was the change in VF, VEP and RNFL thickness. The other secondary end-point was the correlation between visual changes after 6 mon and the VF, VEP and RNFL thickness at baseline of the groups.Results: Idebenone was shown to be safe and well tolerated. The primary end-point reached statistical significance. The VA in the idebenone group improved in both the best eye and worst eye. The mean defect of VF decreased and amplitude of VEP increased. There was no significant difference in latency and RNFL thickness between the groups. The treatment, together with the VA and amplitude at baseline, had a significant effect on the improvement in VA at 6 mon.Conclusion: This case-controlled study of LHON provides evidence that idebenone treatment may be beneficial in cases of LHON and that the influential factors governing outcomes are the VA and amplitude of the VEP at baseline.
    Keywords:  Leber hereditary optic neuropathy; idebenone; visual function
  10. Blood Rev. 2020 Feb 04. pii: S0268-960X(20)30019-9. [Epub ahead of print] 100669
    Zahid MF, Lazarus HM, Ringdén O, Barrett JA, Gale RP, Hashmi SK.
      Acute and chronic graft-versus-host disease (GvHD) are the most important causes of treatment-related morbidity and mortality after allogeneic hematopoietic cell transplants for various diseases. Corticosteroids are an effective therapy in only about one-half of affected individuals and new therapy options are needed. We discuss novel strategies to treat GvHD using cellular-therapy including adoptive transfer of regulatory T-cells (Tregs), mesenchymal stromal cells (MSCs), cells derived from placental tissues, invariant natural killer T-cells (iNKTs), and myeloid-derived suppressor cells (MDSCs).These strategies may be more selective than drugs in modulating GvHD pathophysiology, and may be safer and more effective than conventional pharmacologic therapies. Additionally, these therapies have not been observed to substantially compromise the graft-versus-tumor effect associated with allotransplants. Many of these strategies are effective in animal models but substantial data in humans are lacking.
    Keywords:  Cellular therapy; Graft-versus-host disease; Mesenchymal stromal cells; Placental tissues; Regulatory T-cells
  11. Nanomaterials (Basel). 2020 Feb 20. pii: E364. [Epub ahead of print]10(2):
    Gómez-Aguado I, Rodríguez-Castejón J, Vicente-Pascual M, Rodríguez-Gascón A, Solinís MÁ, Del Pozo-Rodríguez A.
      The use of messenger RNA (mRNA) in gene therapy is increasing in recent years, due to its unique features compared to plasmid DNA: Transient expression, no need to enter into the nucleus and no risk of insertional mutagenesis. Nevertheless, the clinical application of mRNA as a therapeutic tool is limited by its instability and ability to activate immune responses; hence, mRNA chemical modifications together with the design of suitable vehicles result essential. This manuscript includes a revision of the strategies employed to enhance in vitro transcribed (IVT) mRNA functionality and efficacy, including the optimization of its stability and translational efficiency, as well as the regulation of its immunostimulatory properties. An overview of the nanosystems designed to protect the mRNA and to overcome the intra and extracellular barriers for successful delivery is also included. Finally, the present and future applications of mRNA nanomedicines for immunization against infectious diseases and cancer, protein replacement, gene editing, and regenerative medicine are highlighted.
    Keywords:  Chimeric Antigen Receptor (CAR) T cells; cancer immunotherapy; dendritic cells; gene editing; gene therapy; immunotherapy; in vitro transcribed messenger RNA (IVT mRNA); infectious disease vaccines; nanomedicine; protein replacement
  12. Sci Adv. 2020 Feb;6(7): eaax5701
    Wang L, Yang Y, Breton C, Bell P, Li M, Zhang J, Che Y, Saveliev A, He Z, White J, Latshaw C, Xu C, McMenamin D, Yu H, Morizono H, Batshaw ML, Wilson JM.
      Ornithine transcarbamylase (OTC) deficiency is an X-linked urea cycle disorder associated with high mortality. Although a promising treatment for late-onset OTC deficiency, adeno-associated virus (AAV) neonatal gene therapy would only provide short-term therapeutic effects as the non-integrated genome gets lost during hepatocyte proliferation. CRISPR-Cas9-mediated homology-directed repair can correct a G-to-A mutation in 10% of OTC alleles in the livers of newborn OTC spfash mice. However, an editing vector able to correct one mutation would not be applicable for patients carrying different OTC mutations, plus expression would not be fast enough to treat a hyperammonemia crisis. Here, we describe a dual-AAV vector system that accomplishes rapid short-term expression from a non-integrated minigene and long-term expression from the site-specific integration of this minigene without any selective growth advantage for OTC-positive cells in newborns. This CRISPR-Cas9 gene-targeting approach may be applicable to all patients with OTC deficiency, irrespective of mutation and/or clinical state.
  13. Acta Ophthalmol. 2020 Feb 24.
    Liu HL, Yuan JJ, Zhang Y, Tian Z, Li X, Wang D, Du YY, Song L, Li B.
      PURPOSE: To analyse the factors associated with rapid and significant improvement in visual acuity in patients with Leber's hereditary optic neuropathy (LHON) after gene therapy and explain the theory of this improvement.METHODS: We recruited 149 patients with LHON, who underwent gene therapy, and divided them into two groups according to the absence or presence of rapid and significant visual acuity improvements within 3 days of treatment. A bivariate logistic regression model was used to analyse relevant factors including age, the period between onset and treatment, baseline values of best corrected visual acuity (BCVA), visual field index (VFI) and pretreatment average retinal nerve fibre-layer thickness (GRNFL). The corresponding parameters for the injected and non-injected eyes were analysed separately.
    RESULTS: The period between onset and treatment, and pretreatment baseline BCVA was significantly associated with rapid and significant improvement in visual acuity for both, the injected and non-injected eyes. Moreover, pretreatment baseline VFI and GRNFL were not significantly associated with rapid and significant improvement in visual acuity. Age was significantly associated with rapid and significant improvement in visual acuity of the injected eyes.
    CONCLUSION: The period between onset and treatment, and pretreatment baseline BCVA may be important predictors of rapid and significant improvement in visual acuity in patients with LHON after gene therapy.
    Keywords:  Leber's hereditary optic neuropathy; disease progression; gene therapy; visual acuity
  14. Nature. 2018 Mar;555(7695): S23-S25
    King A.
    Keywords:  Cardiovascular biology; Gene therapy; Therapeutics
  15. Blood Coagul Fibrinolysis. 2020 Feb 27.
    Lippi G, Favaloro EJ.
      : Hemophilia comprises two distinct genetic disorders caused by missing or defective clotting factor VIII (hemophilia A) or clotting factor IX (hemophilia B). The management of these conditions has been for long based on replacement therapies, but emerging evidence garnered from recent landmark studies suggests that a promising avenue toward routine use of gene therapy is clearly progressing forward, thus generating unavoidable consequences on laboratory hemostasis, especially as pertaining to phenotypic testing. Although it seems likely that widespread use of gene therapy will be associated with a relative decrease of hemostasis tests requests in this patient population due to the relatively stable effect of transgene delivery and persistent production of endogenous clotting factor, some important aspects persuade us that conventional laboratory diagnostics, especially encompassing activated partial thromboplastin time, as well as one-stage and two-stage clotting factor assays, will not be completely voided in the gene therapy era. In particular, phenotypic testing will remain essential for excluding acquired or sporadic cases of hemophilia, for identifying and titrating factor inhibitors, as well as for defining and monitoring the long-term therapeutic effectiveness of gene transfection in hemophiliacs.
  16. J Pathol. 2020 Feb 26.
    Tsagakis I, Douka K, Birds I, Aspden JL.
      Our genomes contain the blueprint of what makes us human and many indications as to why we develop disease. Until the last ten years, most studies had focussed on protein-coding genes, more specifically DNA sequences coding for proteins. However, this represents less than 5% of our genomes. The other 95% is referred to as the 'dark matter' of our genomes, our understanding of which is extremely limited. Part of this 'dark matter' includes regions that give rise to RNAs that do not code for proteins. A subset of these non-coding RNAs are long non-coding RNAs (lncRNAs), which in particular are beginning to be dissected and their importance to human health revealed. To improve our understanding and treatment of disease it is vital we understand the molecular and cellular function of lncRNAs, and how their mis-regulation can contribute to disease. It is not yet clear what proportion of lncRNAs is actually functional; conservation during evolution is being used to understand the biological importance of lncRNA. Here, we present key themes within the field of lncRNAs, emphasising the importance of their roles in both the nucleus and the cytoplasm of cells, as well as patterns in their modes of action. We discuss their potential functions in development and disease using examples where we have the greatest understanding. Finally, we emphasise why lncRNAs can serve as biomarkers and discuss their emerging potential for therapy. This article is protected by copyright. All rights reserved.
    Keywords:  Long non-coding RNA; X chromosome inactivation; anti-sense lncRNAs; cancer; conservation; development; diabetes; long intergenic non-coding RNA; neurodegenerative disease; stem cells; translation
  17. Biomed Pharmacother. 2020 Feb 21. pii: S0753-3322(20)30200-6. [Epub ahead of print]125 110009
    Bashraheel SS, Domling A, Goda SK.
      BACKGROUND: Until recently, patients who have the same type and stage of cancer all receive the same treatment. It has been established, however, that individuals with the same disease respond differently to the same therapy. Further, each tumor undergoes genetic changes that cause cancer to grow and metastasize. The changes that occur in one person's cancer may not occur in others with the same cancer type. These differences also lead to different responses to treatment. Precision medicine, also known as personalized medicine, is a strategy that allows the selection of a treatment based on the patient's genetic makeup. In the case of cancer, the treatment is tailored to take into account the genetic changes that may occur in an individual's tumor. Precision medicine, therefore, could be defined in terms of the targets involved in targeted therapy.METHODS: A literature search in electronic data bases using keywords "cancer targeted therapy, personalized medicine and cancer combination therapies" was conducted to include papers from 2010 to June 2019.
    RESULTS: Recent developments in strategies of targeted cancer therapy were reported. Specifically, on the two types of targeted therapy; first, immune-based therapy such as the use of immune checkpoint inhibitors (ICIs), immune cytokines, tumor-targeted superantigens (TTS) and ligand targeted therapeutics (LTTs). The second strategy deals with enzyme/small molecules-based therapies, such as the use of a proteolysis targeting chimera (PROTAC), antibody-drug conjugates (ADC) and antibody-directed enzyme prodrug therapy (ADEPT). The precise targeting of the drug to the gene or protein under attack was also investigated, in other words, how precision medicine can be used to tailor treatments.
    CONCLUSION: The conventional therapeutic paradigm for cancer and other diseases has focused on a single type of intervention for all patients. However, a large literature in oncology supports the therapeutic benefits of a precision medicine approach to therapy as well as combination therapies.
    Keywords:  ADEPT; Antibody drug conjugate; Cancer immunotherapy; Checkpoint inhibitors; PROTAC; Precision medicine; Superantigen; Targeted cancer therapy
  18. Curr Med Chem. 2020 Feb 23.
    Li L, Kumar AK, Hu Z, Guo Z.
      DNA damage response (DDR) is a complicated interactional pathway. Defects that occur in subordinate pathways of the DDR pathway can lead to genomic instability and cancer susceptibility. Abnormal expression of some proteins in DDR, especially in the DNA repair pathway, are associated with the subsistence and resistance of cancer cells. Therefore, the development of small molecule inhibitors targeting the chief proteins in the DDR pathway is an effective strategy for cancer therapy. In this review, we summarize the development of small molecule inhibitors targeting chief proteins in the DDR pathway, particularly focusing on their implications for cancer therapy. We present the action mode of DDR molecule inhibitors in preclinical studies and clinical cancer therapy, including monotherapy and combination therapy with chemotherapeutic drugs or checkpoint suppression therapy.
    Keywords:  Cancer therapy; DNA Damage Response (DDR); DNA repair; Small molecule Inhibitor
  19. Regen Med. 2020 Feb 27.
    Coppens DG, Gardarsdottir H, van den Bogert CA, De Bruin ML, Leufkens HG, Hoekman J.
      Aim: We investigated publication rates and reported results for gene- and cell-based therapy trials. Materials & methods: In a cohort of Institutional Review Board (IRB)-authorized trials during 2007-2017 in the Netherlands (n = 105), we examine publication rates and reported results in scientific papers and conference abstracts as well as associations with the occurrence of trial characteristics. Results: The publication rate for scientific papers was 27% and 17% for conference abstracts (median survival time: 1050 days). Academic hospitals published more in scientific papers whereas private sponsors published more in conference abstracts. Manufacturing protocols were underreported compared with clinical outcomes. Most publications reported positive results (78%). Conclusion: Publication rates are currently suboptimal indicating a need for enhanced knowledge sharing to stimulate gene- and cell-based therapy development.
    Keywords:  academic research; clinical trial cohort; clinical trial transparency; commercial development; conference abstract; drug regulatory science; gene- and cell-based therapies; publication bias; scientific publication