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Morais P, Zhang R, Yu YT. Therapeutic Nonsense Suppression Modalities: From Small Molecules to Nucleic Acid-Based Approaches. Biomedicines 2024; 12:1284. [PMID: 38927491 PMCID: PMC11201248 DOI: 10.3390/biomedicines12061284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/29/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Nonsense mutations are genetic mutations that create premature termination codons (PTCs), leading to truncated, defective proteins in diseases such as cystic fibrosis, neurofibromatosis type 1, Dravet syndrome, Hurler syndrome, Beta thalassemia, inherited bone marrow failure syndromes, Duchenne muscular dystrophy, and even cancer. These mutations can also trigger a cellular surveillance mechanism known as nonsense-mediated mRNA decay (NMD) that degrades the PTC-containing mRNA. The activation of NMD can attenuate the consequences of truncated, defective, and potentially toxic proteins in the cell. Since approximately 20% of all single-point mutations are disease-causing nonsense mutations, it is not surprising that this field has received significant attention, resulting in a remarkable advancement in recent years. In fact, since our last review on this topic, new examples of nonsense suppression approaches have been reported, namely new ways of promoting the translational readthrough of PTCs or inhibiting the NMD pathway. With this review, we update the state-of-the-art technologies in nonsense suppression, focusing on novel modalities with therapeutic potential, such as small molecules (readthrough agents, NMD inhibitors, and molecular glue degraders); antisense oligonucleotides; tRNA suppressors; ADAR-mediated RNA editing; targeted pseudouridylation; and gene/base editing. While these various modalities have significantly advanced in their development stage since our last review, each has advantages (e.g., ease of delivery and specificity) and disadvantages (manufacturing complexity and off-target effect potential), which we discuss here.
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Affiliation(s)
- Pedro Morais
- Drug Metabolism and Pharmacokinetics, Research and Development, Bayer Pharmaceuticals, 42113 Wuppertal, Germany
| | - Rui Zhang
- Center for RNA Biology, Department of Biochemistry and Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA;
| | - Yi-Tao Yu
- Center for RNA Biology, Department of Biochemistry and Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA;
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Zhang Y, Gao H, Zhang L, Zhao Y, Qiu C, Liu X. Novel Germline KIT Variants in Families With Severe Piebaldism: Case Series and Literature Review. J Clin Lab Anal 2024; 38:e25073. [PMID: 38887855 PMCID: PMC11252829 DOI: 10.1002/jcla.25073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
INTRODUCTION Piebaldism is a rare autosomal dominant disorder characterized by congenital white forelock and depigmented patches, which is most commonly caused by deleterious variants in the KIT gene. METHODS Four KIT variants were identified in a piebaldism case series by whole-exome sequencing. Functional experiments, including in vitro minigene reporter assay and enzyme-linked immunosorbent assay, were carried out to elucidate the pathogenicity of the variants. The genotype-phenotype correlation was summarized through extensive literature reviewing. RESULTS All the four cases had severe piebaldism presented with typical white forelock and diffuse depigmentation on the ventral trunk and limbs. Four germline variants at the tyrosine kinase (TK) domains of the KIT gene were identified: two novel variants c.1990+1G>A (p.Pro627_Gly664delinsArg) and c.2716T>C (p.Cys906Arg), and two known variants c.1879+1G>A (p.Gly592_Pro627delinsAla) and c.1747G>A (p.Glu583Lys). Both splicing variants caused exon skipping and inframe deletions in the TK1 domain. The missense variants resided at the TK1 and TK2 domains respectively impairing PI3K/AKT and MAPK/ERK signaling pathways, the downstream of KIT. All severe cases were associated with variants in the TK domains, eliciting a major dominant-negative mechanism of the disease. CONCLUSION Our data expand the mutation spectrum of KIT, emphasized by a dominant-negative effect of variants in the critical TK domains in severe cases. We also share the experience of prenatal diagnosis and informed reproductive choices for the affected families.
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Affiliation(s)
- Yuanyuan Zhang
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
| | - Haiming Gao
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
| | - Lu Zhang
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
| | - Yunjing Zhao
- Department of Developmental PediatricsShengjing Hospital of China Medical UniversityShenyangChina
| | - Chuang Qiu
- Department of OrthopedicsShengjing Hospital of China Medical UniversityShenyangChina
| | - Xiaoliang Liu
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
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Chen JL, Leeder WM, Morais P, Adachi H, Yu YT. Pseudouridylation-mediated gene expression modulation. Biochem J 2024; 481:1-16. [PMID: 38174858 DOI: 10.1042/bcj20230096] [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: 10/14/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
RNA-guided pseudouridylation, a widespread post-transcriptional RNA modification, has recently gained recognition for its role in cellular processes such as pre-mRNA splicing and the modulation of premature termination codon (PTC) readthrough. This review provides insights into its mechanisms, functions, and potential therapeutic applications. It examines the mechanisms governing RNA-guided pseudouridylation, emphasizing the roles of guide RNAs and pseudouridine synthases in catalyzing uridine-to-pseudouridine conversion. A key focus is the impact of RNA-guided pseudouridylation of U2 small nuclear RNA on pre-mRNA splicing, encompassing its influence on branch site recognition and spliceosome assembly. Additionally, the review discusses the emerging role of RNA-guided pseudouridylation in regulating PTC readthrough, impacting translation termination and genetic disorders. Finally, it explores the therapeutic potential of pseudouridine modifications, offering insights into potential treatments for genetic diseases and cancer and the development of mRNA vaccine.
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Affiliation(s)
- Jonathan L Chen
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY, U.S.A
| | | | | | - Hironori Adachi
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY, U.S.A
| | - Yi-Tao Yu
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY, U.S.A
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van Velthoven AJH, Utheim TP, Notara M, Bremond-Gignac D, Figueiredo FC, Skottman H, Aberdam D, Daniels JT, Ferrari G, Grupcheva C, Koppen C, Parekh M, Ritter T, Romano V, Ferrari S, Cursiefen C, Lagali N, LaPointe VLS, Dickman MM. Future directions in managing aniridia-associated keratopathy. Surv Ophthalmol 2023; 68:940-956. [PMID: 37146692 DOI: 10.1016/j.survophthal.2023.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/07/2023]
Abstract
Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive loss of corneal transparency and thereby loss of vision. Currently, there is no approved therapy to delay or prevent its progression, and clinical management is challenging because of phenotypic variability and high risk of complications after interventions; however, new insights into the molecular pathogenesis of AAK may help improve its management. Here, we review the current understanding about the pathogenesis and management of AAK. We highlight the biological mechanisms involved in AAK development with the aim to develop future treatment options, including surgical, pharmacological, cell therapies, and gene therapies.
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Affiliation(s)
- Arianne J H van Velthoven
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands; University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands
| | - Tor P Utheim
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway; Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Maria Notara
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Dominique Bremond-Gignac
- Ophthalmology Department, University Hospital Necker-Enfants Malades, APHP, Paris Cité University, Paris, France; Centre de Recherche des Cordeliers, Sorbonne Paris Cité University, Paris, France
| | - Francisco C Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UK; Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Heli Skottman
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Daniel Aberdam
- Centre de Recherche des Cordeliers, Sorbonne Paris Cité University, Paris, France
| | | | - Giulio Ferrari
- Cornea and Ocular Surface Unit, Eye Repair Lab, San Raffaele Hospital, Milan, Italy
| | - Christina Grupcheva
- Department of Ophthalmology and Visual Sciences, Medical University of Varna, Varna, Bulgaria
| | - Carina Koppen
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Mohit Parekh
- Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA
| | - Thomas Ritter
- Regenerative Medicine Institute, University of Galway, Galway, Ireland
| | - Vito Romano
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, Brescia, Italy
| | | | - Claus Cursiefen
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Neil Lagali
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Vanessa L S LaPointe
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
| | - Mor M Dickman
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands; University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands
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Roshandel D, Semnani F, Rayati Damavandi A, Masoudi A, Baradaran-Rafii A, Watson SL, Morgan WH, McLenachan S. Genetic predisposition to ocular surface disorders and opportunities for gene-based therapies. Ocul Surf 2023; 29:150-165. [PMID: 37192706 DOI: 10.1016/j.jtos.2023.05.003] [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: 02/28/2023] [Revised: 04/24/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023]
Abstract
The ocular surface, comprised of the corneal and conjunctival epithelium, innervation system, immune components, and tear-film apparatus, plays a key role in ocular integrity as well as comfort and vision. Gene defects may result in congenital ocular or systemic disorders with prominent ocular surface involvement. Examples include epithelial corneal dystrophies, aniridia, ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, xeroderma pigmentosum (XP), and hereditary sensory and autonomic neuropathy. In addition, genetic factors may interact with environmental risk factors in the development of several multifactorial ocular surface disorders (OSDs) such as autoimmune disorders, allergies, neoplasms, and dry eye disease. Advanced gene-based technologies have already been introduced in disease modelling and proof-of-concept gene therapies for monogenic OSDs. For instance, patient-derived induced pluripotent stem cells have been used for modelling aniridia-associated keratopathy (AAK), XP, and EEC syndrome. Moreover, CRISPR/Cas9 genome editing has been used for disease modelling and/or gene therapy for AAK and Meesmann's epithelial corneal dystrophy. A better understanding of the role of genetic factors in OSDs may be helpful in designing personalized disease models and treatment approaches. Gene-based approaches in monogenic OSDs and genetic predisposition to multifactorial OSDs such as immune-mediated disorders and neoplasms with known or possible genetic risk factors has been seldom reviewed. In this narrative review, we discuss the role of genetic factors in monogenic and multifactorial OSDs and potential opportunities for gene therapy.
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Affiliation(s)
- Danial Roshandel
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia
| | - Farbod Semnani
- School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran; School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Amirmasoud Rayati Damavandi
- School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran; School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Ali Masoudi
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Alireza Baradaran-Rafii
- Department of Ophthalmology, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Stephanie L Watson
- The University of Sydney, Save Sight Institute, Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - William H Morgan
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia
| | - Samuel McLenachan
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia.
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Leung A, Sacristan-Reviriego A, Perdigão PRL, Sai H, Georgiou M, Kalitzeos A, Carr AJF, Coffey PJ, Michaelides M, Bainbridge J, Cheetham ME, van der Spuy J. Investigation of PTC124-mediated translational readthrough in a retinal organoid model of AIPL1-associated Leber congenital amaurosis. Stem Cell Reports 2022; 17:2187-2202. [PMID: 36084639 PMCID: PMC9561542 DOI: 10.1016/j.stemcr.2022.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 10/26/2022] Open
Abstract
Leber congenital amaurosis type 4 (LCA4), caused by AIPL1 mutations, is characterized by severe sight impairment in infancy and rapidly progressing degeneration of photoreceptor cells. We generated retinal organoids using induced pluripotent stem cells (iPSCs) from renal epithelial cells obtained from four children with AIPL1 nonsense mutations. iPSC-derived photoreceptors exhibited the molecular hallmarks of LCA4, including undetectable AIPL1 and rod cyclic guanosine monophosphate (cGMP) phosphodiesterase (PDE6) compared with control or CRISPR-corrected organoids. Increased levels of cGMP were detected. The translational readthrough-inducing drug (TRID) PTC124 was investigated as a potential therapeutic agent. LCA4 retinal organoids exhibited low levels of rescue of full-length AIPL1. However, this was insufficient to fully restore PDE6 in photoreceptors and reduce cGMP. LCA4 retinal organoids are a valuable platform for in vitro investigation of novel therapeutic agents.
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Affiliation(s)
- Amy Leung
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | | | | | - Hali Sai
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | | | | | - Michel Michaelides
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - James Bainbridge
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
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Lombardi S, Testa MF, Pinotti M, Branchini A. Translation termination codons in protein synthesis and disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 132:1-48. [PMID: 36088072 DOI: 10.1016/bs.apcsb.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fidelity of protein synthesis, a process shaped by several mechanisms involving specialized ribosome regions and external factors, ensures the precise reading of sense as well as stop codons (UGA, UAG, UAA), which are usually localized at the 3' of mRNA and drive the release of the polypeptide chain. However, either natural (NTCs) or premature (PTCs) termination codons, the latter arising from nucleotide changes, can undergo a recoding process named ribosome or translational readthrough, which insert specific amino acids (NTCs) or subset(s) depending on the stop codon type (PTCs). This process is particularly relevant for nonsense mutations, a relatively frequent cause of genetic disorders, which impair gene expression at different levels by potentially leading to mRNA degradation and/or synthesis of truncated proteins. As a matter of fact, many efforts have been made to develop efficient and safe readthrough-inducing compounds, which have been challenged in several models of human disease to provide with a therapy. In this view, the dissection of the molecular determinants shaping the outcome of readthrough, namely nucleotide and protein contexts as well as their interplay and impact on protein structure/function, is crucial to identify responsive nonsense mutations resulting in functional full-length proteins. The interpretation of experimental and mechanistic findings is also important to define a possibly clear picture of potential readthrough-favorable features useful to achieve rescue profiles compatible with therapeutic thresholds typical of each targeted disorder, which is of primary importance for the potential translatability of readthrough into a personalized and mutation-specific, and thus patient-oriented, therapeutic strategy.
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Affiliation(s)
- Silvia Lombardi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Maria Francesca Testa
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
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Bezzerri V, Lentini L, Api M, Busilacchi EM, Cavalieri V, Pomilio A, Diomede F, Pegoraro A, Cesaro S, Poloni A, Pace A, Trubiani O, Lippi G, Pibiri I, Cipolli M. Novel Translational Read-through-Inducing Drugs as a Therapeutic Option for Shwachman-Diamond Syndrome. Biomedicines 2022; 10:biomedicines10040886. [PMID: 35453634 PMCID: PMC9024944 DOI: 10.3390/biomedicines10040886] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/03/2022] [Accepted: 04/06/2022] [Indexed: 02/01/2023] Open
Abstract
Shwachman-Diamond syndrome (SDS) is one of the most commonly inherited bone marrow failure syndromes (IBMFS). In SDS, bone marrow is hypocellular, with marked neutropenia. Moreover, SDS patients have a high risk of developing myelodysplastic syndrome (MDS), which in turn increases the risk of acute myeloid leukemia (AML) from an early age. Most SDS patients are heterozygous for the c.183-184TA>CT (K62X) SBDS nonsense mutation. Fortunately, a plethora of translational read-through inducing drugs (TRIDs) have been developed and tested for several rare inherited diseases due to nonsense mutations so far. The authors previously demonstrated that ataluren (PTC124) can restore full-length SBDS protein expression in bone marrow stem cells isolated from SDS patients carrying the nonsense mutation K62X. In this study, the authors evaluated the effect of a panel of ataluren analogues in restoring SBDS protein resynthesis and function both in hematological and non-hematological SDS cells. Besides confirming that ataluren can efficiently induce SBDS protein re-expression in SDS cells, the authors found that another analogue, namely NV848, can restore full-length SBDS protein synthesis as well, showing very low toxicity in zebrafish. Furthermore, NV848 can improve myeloid differentiation in bone marrow hematopoietic progenitors, enhancing neutrophil maturation and reducing the number of dysplastic granulocytes in vitro. Therefore, these findings broaden the possibilities of developing novel therapeutic options in terms of nonsense mutation suppression for SDS. Eventually, this study may act as a proof of concept for the development of similar approaches for other IBMFS caused by nonsense mutations.
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Affiliation(s)
- Valentino Bezzerri
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, 37126 Verona, Italy; (V.B.); (A.P.)
| | - Laura Lentini
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), University of Palermo, 90128 Palermo, Italy; (L.L.); (V.C.); (A.P.); (I.P.)
| | - Martina Api
- Cystic Fibrosis Center of Ancona, Azienda Ospedaliero Universitaria Ospedali Riuniti, 60126 Ancona, Italy;
| | - Elena Marinelli Busilacchi
- Hematology Clinic, Università Politecnica delle Marche, AOU Ospedali Riuniti, 60126 Ancona, Italy; (E.M.B.); (A.P.)
| | - Vincenzo Cavalieri
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), University of Palermo, 90128 Palermo, Italy; (L.L.); (V.C.); (A.P.); (I.P.)
- Zebrafish Laboratory, Advanced Technologies Network (ATeN) Center, University of Palermo, 90128 Palermo, Italy
| | - Antonella Pomilio
- Department of Medical, Oral and Biotechnological Sciences, G. D’Annunzio University of Chieti-Pescara, 66100 Chieti, Italy;
| | - Francesca Diomede
- Dipartimento di Tecnologie Innovative in Medicina e Odontoiatria, G. D’Annunzio University of Chieti-Pescara, 66100 Chieti, Italy; (F.D.); (O.T.)
| | - Anna Pegoraro
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, 37126 Verona, Italy; (V.B.); (A.P.)
| | - Simone Cesaro
- Unit of Pediatric Hematology Oncology, Azienda Ospedaliera Universitaria Integrata, 37126 Verona, Italy;
| | - Antonella Poloni
- Hematology Clinic, Università Politecnica delle Marche, AOU Ospedali Riuniti, 60126 Ancona, Italy; (E.M.B.); (A.P.)
| | - Andrea Pace
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), University of Palermo, 90128 Palermo, Italy; (L.L.); (V.C.); (A.P.); (I.P.)
| | - Oriana Trubiani
- Dipartimento di Tecnologie Innovative in Medicina e Odontoiatria, G. D’Annunzio University of Chieti-Pescara, 66100 Chieti, Italy; (F.D.); (O.T.)
| | - Giuseppe Lippi
- Section of Clinical Biochemistry, University of Verona, 37126 Verona, Italy;
| | - Ivana Pibiri
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), University of Palermo, 90128 Palermo, Italy; (L.L.); (V.C.); (A.P.); (I.P.)
| | - Marco Cipolli
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, 37126 Verona, Italy; (V.B.); (A.P.)
- Correspondence: ; Tel.: +39-045-812-2293
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Martins-Dias P, Romão L. Nonsense suppression therapies in human genetic diseases. Cell Mol Life Sci 2021; 78:4677-4701. [PMID: 33751142 PMCID: PMC11073055 DOI: 10.1007/s00018-021-03809-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/06/2021] [Accepted: 03/05/2021] [Indexed: 02/06/2023]
Abstract
About 11% of all human disease-associated gene lesions are nonsense mutations, resulting in the introduction of an in-frame premature translation-termination codon (PTC) into the protein-coding gene sequence. When translated, PTC-containing mRNAs originate truncated and often dysfunctional proteins that might be non-functional or have gain-of-function or dominant-negative effects. Therapeutic strategies aimed at suppressing PTCs to restore deficient protein function-the so-called nonsense suppression (or PTC readthrough) therapies-have the potential to provide a therapeutic benefit for many patients and in a broad range of genetic disorders, including cancer. These therapeutic approaches comprise the use of translational readthrough-inducing compounds that make the translational machinery recode an in-frame PTC into a sense codon. However, most of the mRNAs carrying a PTC can be rapidly degraded by the surveillance mechanism of nonsense-mediated decay (NMD), thus decreasing the levels of PTC-containing mRNAs in the cell and their availability for PTC readthrough. Accordingly, the use of NMD inhibitors, or readthrough-compound potentiators, may enhance the efficiency of PTC suppression. Here, we review the mechanisms of PTC readthrough and their regulation, as well as the recent advances in the development of novel approaches for PTC suppression, and their role in personalized medicine.
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Affiliation(s)
- Patrícia Martins-Dias
- Department of Human Genetics, Instituto Nacional de Saúde Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal
- Faculty of Sciences, BioISI-Biosystems and Integrative Sciences Institute, University of Lisboa, 1749-016, Lisbon, Portugal
| | - Luísa Romão
- Department of Human Genetics, Instituto Nacional de Saúde Doutor Ricardo Jorge, Av. Padre Cruz, 1649-016, Lisbon, Portugal.
- Faculty of Sciences, BioISI-Biosystems and Integrative Sciences Institute, University of Lisboa, 1749-016, Lisbon, Portugal.
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Formulation and Stability of Ataluren Eye Drop Oily Solution for Aniridia. Pharmaceutics 2020; 13:pharmaceutics13010007. [PMID: 33375041 PMCID: PMC7822034 DOI: 10.3390/pharmaceutics13010007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/15/2022] Open
Abstract
Congenital aniridia is a rare and severe panocular disease characterized by a complete or partial iris defect clinically detectable at birth. The most common form of aniridia occurring in around 90% of cases is caused by PAX6 haploinsufficiency. The phenotype includes ptosis, nystagmus, corneal limbal insufficiency, glaucoma, cataract, optic nerve, and foveal hypoplasia. Ataluren eye drops aim to restore ocular surface PAX6 haploinsufficiency in aniridia-related keratopathy (ARK). However, there are currently no available forms of the ophthalmic solution. The objective of this study was to assess the physicochemical and microbiological stability of ataluren 1% eye drop in preservative-free low-density polyethylene (LDPE) bottle with an innovative insert that maintains sterility after opening. Because ataluren is a strongly lipophilic compound, the formulation is complex and involves a strategy based on co-solvents in an aqueous phase or an oily formulation capable of totally dissolving the active ingredient. The visual aspect, ataluren quantification by a stability-indicating chromatographic method, and microbiological sterility were analyzed. The oily formulation in castor oil and DMSO (10%) better protects ataluren hydrolysis and oxidative degradation and permits its complete solubilization. Throughout the 60 days period, the oily solution in the LDPE bottle remained clear without any precipitation or color modification, and no drug loss and no microbial development were detected. The demonstrated physical and microbiological stability of ataluren 1% eye drop formulation at 22–25 °C might facilitate clinical research in aniridia.
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Nonsense Suppression Therapy: New Hypothesis for the Treatment of Inherited Bone Marrow Failure Syndromes. Int J Mol Sci 2020; 21:ijms21134672. [PMID: 32630050 PMCID: PMC7369780 DOI: 10.3390/ijms21134672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 12/13/2022] Open
Abstract
Inherited bone marrow failure syndromes (IBMFS) are a group of cancer-prone genetic diseases characterized by hypocellular bone marrow with impairment in one or more hematopoietic lineages. The pathogenesis of IBMFS involves mutations in several genes which encode for proteins involved in DNA repair, telomere biology and ribosome biogenesis. The classical IBMFS include Shwachman–Diamond syndrome (SDS), Diamond–Blackfan anemia (DBA), Fanconi anemia (FA), dyskeratosis congenita (DC), and severe congenital neutropenia (SCN). IBMFS are associated with high risk of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and solid tumors. Unfortunately, no specific pharmacological therapies have been highly effective for IBMFS. Hematopoietic stem cell transplantation provides a cure for aplastic or myeloid neoplastic complications. However, it does not affect the risk of solid tumors. Since approximately 28% of FA, 24% of SCN, 21% of DBA, 20% of SDS, and 17% of DC patients harbor nonsense mutations in the respective IBMFS-related genes, we discuss the use of the nonsense suppression therapy in these diseases. We recently described the beneficial effect of ataluren, a nonsense suppressor drug, in SDS bone marrow hematopoietic cells ex vivo. A similar approach could be therefore designed for treating other IBMFS. In this review we explain in detail the new generation of nonsense suppressor molecules and their mechanistic roles. Furthermore, we will discuss strengths and limitations of these molecules which are emerging from preclinical and clinical studies. Finally we discuss the state-of-the-art of preclinical and clinical therapeutic studies carried out for IBMFS.
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Liu X, Zhang Y, Zhang B, Gao H, Qiu C. Nonsense suppression induced readthrough of a novel PAX6 mutation in patient-derived cells of congenital aniridia. Mol Genet Genomic Med 2020; 8:e1198. [PMID: 32125788 PMCID: PMC7216799 DOI: 10.1002/mgg3.1198] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 12/11/2022] Open
Abstract
Background Congenital aniridia is a severe ocular abnormality characterized by incomplete formation of the iris and many other ocular complications. Most cases are caused by the paired box 6 (PAX6) gene mutations generating premature termination codons (PTCs). Methods Ophthalmic examination was performed on a Chinese pedigree with congenital aniridia. The mutation was identified by targeted next‐generation sequencing. Nonsense suppression therapy was applied on patient‐derived lymphocytes. The PAX6 expression was assayed by real‐time polymerase chain reaction and Western blot. Results Complete aniridia was complicated with horizontal nystagmus, contract, foveal hypoplasia, and microphthalmia. A novel heterozygous c.702_703delinsAT (p.Tyr234*) mutation was found in exon 9 of PAX6, generating a PTC at the homeodomain. There were about 50% reductions of both full‐length PAX6 protein and PAX6 mRNA in patient‐derived lymphocytes, indicating haploinsufficiency due to nonsense‐mediated mRNA decay. Ataluren (PTC124) and geneticin (G418) could induce about 30%–40% translational readthrough. Nonsense suppression therapy restored PAX6 protein to about 65%–70% of unaffected family controls. Conclusion Our data expanded the genetic and phenotypic variations of congenital aniridia, and showed the therapeutic effect of nonsense suppression on this disease using patient‐derived cells.
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Affiliation(s)
- Xiaoliang Liu
- Department of Clinical Genetics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yuanyuan Zhang
- Department of Clinical Genetics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Bijun Zhang
- Department of Clinical Genetics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Haiming Gao
- Department of Clinical Genetics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Chuang Qiu
- Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, China
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