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Kim CJ, Singh C, Lee C, DiMagno K, O'Donnell M, Kaczmarek M, Ahmed A, Salvo‐Schaich J, Perez A, Letsou W, Sepulveda MC, Ramos RL, Hadjiargyrou M. Mustn1 ablation in skeletal muscle results in increased glucose tolerance concomitant with upregulated GLUT expression in male mice. Physiol Rep 2023; 11:e15674. [PMID: 37170065 PMCID: PMC10175242 DOI: 10.14814/phy2.15674] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 05/13/2023] Open
Abstract
Glucose homeostasis is closely regulated to maintain energy requirements of vital organs and skeletal muscle plays a crucial role in this process. Mustn1 is expressed during embryonic and postnatal skeletal muscle development and its function has been implicated in myogenic differentiation and myofusion. Whether Mustn1 plays a role in glucose homeostasis in anyway remains largely unknown. As such, we deleted Mustn1 in skeletal muscle using a conditional knockout (KO) mouse approach. KO mice did not reveal any specific gross phenotypic alterations in skeletal muscle. However, intraperitoneal glucose tolerance testing (IPGTT) revealed that 2-month-old male KO mice had significantly lower glycemia than their littermate wild type (WT) controls. These findings coincided with mRNA changes in genes known to be involved in glucose metabolism, tolerance, and insulin sensitivity; 2-month-old male KO mice had significantly higher expression of GLUT1 and GLUT10 transporters, MUP-1 while OSTN expression was lower. These differences in glycemia and gene expression were statistically insignificant after 4 months. Identical experiments in female KO and WT control mice did not indicate any differences at any age. Our results suggest a link between Mustn1 expression and glucose homeostasis during a restricted period of skeletal muscle development/maturation. While this is an observational study, Mustn1's relationship to glucose homeostasis appears to be more complex with a possible connection to other key proteins such as GLUTs, MUP-1, and OSTN. Additionally, our data indicate temporal and sex differences. Lastly, our findings strengthen the notion that Mustn1 plays a role in the metabolic capacity of skeletal muscle.
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Affiliation(s)
- Charles J. Kim
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
- Department of Biological and Chemical SciencesNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Chanpreet Singh
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Christine Lee
- Department of Biological and Chemical SciencesNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Kevin DiMagno
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Madison O'Donnell
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Marina Kaczmarek
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Arhum Ahmed
- Department of Biological and Chemical SciencesNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Jessica Salvo‐Schaich
- Department of Biological and Chemical SciencesNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Alexis Perez
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - William Letsou
- Department of Biological and Chemical SciencesNew York Institute of TechnologyOld WestburyNew YorkUSA
| | | | - Raddy L. Ramos
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
| | - Michael Hadjiargyrou
- College of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNew YorkUSA
- Department of Biological and Chemical SciencesNew York Institute of TechnologyOld WestburyNew YorkUSA
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Polymeric nanoparticles functionalized with muscle-homing peptides for targeted delivery of phosphatase and tensin homolog inhibitor to skeletal muscle. Acta Biomater 2020; 118:196-206. [PMID: 33053428 DOI: 10.1016/j.actbio.2020.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/01/2020] [Accepted: 10/07/2020] [Indexed: 12/30/2022]
Abstract
Phosphatase and tensin homolog (PTEN) antagonizes muscle growth and repair, and inhibition of PTEN has been shown to improve the pathophysiology and dystrophic muscle function in a mouse model of Duchenne muscular dystrophy (DMD). However, conventional pharmacological delivery of PTEN inhibitors carries a high risk of off-target side effects in other non-muscle organs due to broad targeting spectrums. Here we report a muscle-targeted nanoparticulate platform for cell-specific delivery of a PTEN inhibitor. Poly(lactide-co-glycolide)-b-poly(ethylene glycol) nanoparticles (NPs) are functionalized with a muscle-homing peptide M12 to promote the selective uptake by muscle cells/tissue in vitro and in vivo. Moreover, the NPs are formulated to slowly release the PTEN inhibitor, preventing cytotoxicity associated with direct exposure to the drug and facilitating sustained inhibition of PTEN. This advanced delivery approach taking advantages of polymeric nanomaterials and muscle-homing peptides opens a new avenue for the development of long-term therapeutic strategies in DMD treatment.
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Schneider AFE, Aartsma-Rus A. Developments in reading frame restoring therapy approaches for Duchenne muscular dystrophy. Expert Opin Biol Ther 2020; 21:343-359. [PMID: 33074029 DOI: 10.1080/14712598.2021.1832462] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Exon skipping compounds restoring the dystrophin transcript reading frame have received regulatory approval for Duchenne muscular dystrophy (DMD). Recently, focus shifted to developing compounds to skip additional exons, improving delivery to skeletal muscle, and to genome editing, to restore the reading frame on DNA level. AREAS COVERED We outline developments for reading frame restoring approaches, challenges of mutation specificity, and optimizing delivery. Also, we highlight ongoing efforts to better detect exon skipping therapeutic effects in clinical trials. Searches on relevant terms were performed, focusing on recent publications (<3 years). EXPERT OPINION Currently, 3 AONS are approved. Whether dystrophin levels are sufficient to slowdown disease progression needs to be confirmed. Enhancing AON uptake by muscles is currently under investigation. Gene editing is an alternative, but one that involves practical and ethical concerns. Given the field's momentum, we believe the efficiency of frame-restoring approaches will improve.
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Affiliation(s)
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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Wang M, Wu B, Shah SN, Lu P, Lu Q. Aminoglycoside Enhances the Delivery of Antisense Morpholino Oligonucleotides In Vitro and in mdx Mice. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 16:663-674. [PMID: 31121478 PMCID: PMC6529765 DOI: 10.1016/j.omtn.2019.04.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/23/2019] [Accepted: 04/23/2019] [Indexed: 01/16/2023]
Abstract
Antisense oligonucleotide (AO) therapy has been the specific treatment for Duchenne muscular dystrophy, with ongoing clinical trials. However, therapeutic applications of AOs remain limited, particularly because of the lack of efficient cellular delivery methods imperative for achieving efficacy. In this study, we investigated a few aminoglycosides (AGs) for their potential to improve the delivery of antisense phosphorodiamidate morpholino oligomer (PMO) both in vitro and in vivo. AGs had lower cytotoxicity compared with Endoporter, the currently most effective delivery reagent for PMO in vitro, and improved efficiency in PMO delivery 9- to 15-fold over PMO alone. Significant enhancement in systemic PMO-targeted dystrophin exon 23 skipping was observed in mdx mice, up to a 6-fold increase with AG3 (kanamycin) and AG7 (sisomicin) compared with PMO only. No muscle damage could be detected clearly with the test dosages. These results establish AGs as PMO delivery-enhancing agents for treating muscular dystrophy or other diseases.
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Affiliation(s)
- Mingxing Wang
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, USA.
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, USA
| | - Sapana N Shah
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, USA
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, USA
| | - Qilong Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, USA
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5
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Han G, Gao X, Yin H. Use of Glucose-Fructose to Enhance the Exon Skipping Efficacy. Methods Mol Biol 2019; 1828:327-342. [PMID: 30171551 DOI: 10.1007/978-1-4939-8651-4_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exon-skipping antisense oligonucleotides (AOs) are promising treatments for muscle-related genetic ailments including Duchenne muscular dystrophy (DMD), but clinical translation is unfortunately hampered by insufficient systemic delivery. Here we describe that how one can employ a glucose-fructose injection mixture to improve muscle uptake and functional outcomes of DMD AOs in energy-deficient peripheral muscles of mdx mice. The potentiating effect of glucose-fructose on AOs in energy-deficient muscles offers a simple and economical method for enhancing AO potency, reducing screening costs for researchers and accelerating the translation of nucleic acid-based therapeutics in DMD and other muscular dystrophies.
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Affiliation(s)
- Gang Han
- Department of Cell Biology & School of Medical Laboratory, Tianjin Medical University, Tianjin, China
| | - Xianjun Gao
- Department of Cell Biology & School of Medical Laboratory, Tianjin Medical University, Tianjin, China
| | - Haifang Yin
- Department of Cell Biology & School of Medical Laboratory, Tianjin Medical University, Tianjin, China.
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6
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Liu X, Liu M, Wu L, Liang D. Gene Therapy for Hemophilia and Duchenne Muscular Dystrophy in China. Hum Gene Ther 2019; 29:146-150. [PMID: 29366352 DOI: 10.1089/hum.2017.213] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Gene therapy is a new technology that provides potential for curing monogenic diseases caused by mutations in a single gene. Hemophilia and Duchenne muscular dystrophy (DMD) are ideal target diseases of gene therapy. Important advances have been made in clinical trials, including studies of adeno-associated virus vectors in hemophilia and antisense in DMD. However, issues regarding the high doses of viral vectors required and limited delivery efficiency of antisense oligonucleotides have not yet been fully addressed. As an alternative strategy to classic gene addition, genome editing based on programmable nucleases has also shown promise to correct mutations in situ. This review describes the recent progress made by Chinese researchers in gene therapy for hemophilia and DMD.
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Affiliation(s)
- Xionghao Liu
- 1 School of Life Sciences, Central South University , Changsha, China
| | - Mujun Liu
- 1 School of Life Sciences, Central South University , Changsha, China
| | - Lingqian Wu
- 1 School of Life Sciences, Central South University , Changsha, China .,2 Hunan Jiahui Genetics Hospital , Changsha, China
| | - Desheng Liang
- 1 School of Life Sciences, Central South University , Changsha, China
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Wang M, Wu B, Shah SN, Lu P, Lu Q. Saponins enhance exon skipping of 2'-O-methyl phosphorothioate oligonucleotide in vitro and in vivo. Drug Des Devel Ther 2018; 12:3705-3715. [PMID: 30464402 PMCID: PMC6217006 DOI: 10.2147/dddt.s179008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Antisense oligonucleotide (ASO)-mediated exon skipping has been feasible and promising approach for treating Duchenne muscular dystrophy (DMD) in preclinical and clinical trials, but its therapeutic applications remain challenges due to inefficient delivery. METHODS We investigated a few Saponins for their potential to improve delivery performance of an antisense 2'-Omethyl phosphorothioate RNA (2'-OMePS) in muscle cells and in dystrophic mdx mice. This study was carried out by evaluating these Saponins' toxicity, cellular uptake, transduction efficiency in vitro, and local delivery in vivo for 2'-OMePS, as well as affinity study between Saponin and 2'-OMePS. RESULTS The results showed that these Saponins, especially Digitonin and Tomatine, enhance the delivery of 2'-OMePS with comparable efficiency to Lipofectamine 2k (LF-2k) -mediated delivery in vitro. Significant performance was further observed in mdx mice, up to 10-fold with the Digitonin as compared to 2'-OMePS alone. Cytotoxicity of the Digitonin and Glycyrrhizin was much lower than LF-2k in vitro and not clearly detected in vivo under the tested concentrations. CONCLUSION This study potentiates Saponins as delivery vehicle for 2'-OMePS in vivo for treating DMD or other diseases.
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Affiliation(s)
- Mingxing Wang
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA,
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA,
| | - Sapana N Shah
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA,
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA,
| | - Qilong Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA,
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Han G, Lin C, Ning H, Gao X, Yin H. Long-Term Morpholino Oligomers in Hexose Elicits Long-Lasting Therapeutic Improvements in mdx Mice. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 12:478-489. [PMID: 30195785 PMCID: PMC6070676 DOI: 10.1016/j.omtn.2018.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 12/24/2022]
Abstract
Approval of antisense oligonucleotide eteplirsen highlights the promise of exon-skipping therapeutics for Duchenne muscular dystrophy patients. However, the limited efficacy of eteplirsen underscores the importance to improve systemic delivery and efficacy. Recently, we demonstrated that a glucose and fructose (GF) delivery formulation effectively potentiates phosphorodiamidate morpholino oligomer (PMO). Considering the clinical potential of GF, it is important to determine the long-term compatibility and efficacy with PMO in mdx mice prior to clinical translation. Here, we report that yearlong administration of a clinically applicable PMO dose (50 mg/kg/week for 3 weeks followed by 50 mg/kg/month for 11 months) with GF elicited sustainably high levels of dystrophin expression in mdx mice, with up to 45% of the normal level of dystrophin restored in most peripheral muscles without any detectable toxicity. Importantly, PMO-GF resulted in phenotypical rescue and mitochondrial biogenesis with functional improvement. Carbohydrate metabolites measurements revealed improved metabolic and energetic conditions after PMO-GF treatment in mdx mice without metabolic anomaly. Collectively, our study shows PMO-GF’s ability to elicit long-lasting therapeutic effects with tolerable toxicity and represents a new treatment modality for Duchenne muscular dystrophy, and provides guidelines for antisense oligonucleotides with GF in clinical use.
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Affiliation(s)
- Gang Han
- School of Medical Laboratory and Department of Cell Biology, Tianjin Medical University, Qixiangtai Road, Heping District, Tianjin 300070, China
| | - Caorui Lin
- School of Medical Laboratory and Department of Cell Biology, Tianjin Medical University, Qixiangtai Road, Heping District, Tianjin 300070, China
| | - Hanhan Ning
- School of Medical Laboratory and Department of Cell Biology, Tianjin Medical University, Qixiangtai Road, Heping District, Tianjin 300070, China
| | - Xianjun Gao
- School of Medical Laboratory and Department of Cell Biology, Tianjin Medical University, Qixiangtai Road, Heping District, Tianjin 300070, China
| | - HaiFang Yin
- School of Medical Laboratory and Department of Cell Biology, Tianjin Medical University, Qixiangtai Road, Heping District, Tianjin 300070, China.
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Wang M, Wu B, Shah SN, Lu P, Lu Q. Saponins as Natural Adjuvant for Antisense Morpholino Oligonucleotides Delivery In Vitro and in mdx Mice. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 11:192-202. [PMID: 29858054 PMCID: PMC5992344 DOI: 10.1016/j.omtn.2018.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/14/2018] [Accepted: 02/14/2018] [Indexed: 01/16/2023]
Abstract
Antisense oligonucleotide (AON) therapy for Duchenne muscular dystrophy has drawn great attention in preclinical and clinical trials, but its therapeutic applications are still limited due to inefficient delivery. In this study, we investigated a few saponins for their potential to improve delivery performance of an antisense phosphorodiamidate morpholino oligomer (PMO) both in vitro and in vivo. The results showed that these saponins, especially digitonin and tomatine, improve the delivery efficiency of PMO comparable to Endo-Porter-mediated PMO delivery in vitro. The significant enhancement of PMO targeting to dystrophin exon 23 delivery was further observed in mdx mice up to 7-fold with the digitonin as compared to PMO alone. Cytotoxicity of the digitonin and glycyrrhizin was lower than Endo-Porter in vitro and not clearly detected in vivo under the tested concentrations. These results demonstrate that optimization of saponins in molecular size and composition are key factors to achieve enhanced PMO exon-skipping efficiency. The higher efficiency and lower toxicity endow saponins as gene/AON delivery enhancing agents for treating muscular dystrophy or other diseases.
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Affiliation(s)
- Mingxing Wang
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203, USA.
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203, USA
| | - Sapana N Shah
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203, USA
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203, USA
| | - Qilong Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203, USA
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10
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An Overview of Recent Advances and Clinical Applications of Exon Skipping and Splice Modulation for Muscular Dystrophy and Various Genetic Diseases. Methods Mol Biol 2018; 1828:31-55. [PMID: 30171533 DOI: 10.1007/978-1-4939-8651-4_2] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Exon skipping is a therapeutic approach that is feasible for various genetic diseases and has been studied and developed for over two decades. This approach uses antisense oligonucleotides (AON) to modify the splicing of pre-mRNA to correct the mutation responsible for a disease, or to suppress a particular gene expression, as in allergic diseases. Antisense-mediated exon skipping is most extensively studied in Duchenne muscular dystrophy (DMD) and has developed from in vitro proof-of-concept studies to clinical trials targeting various single exons such as exon 45 (casimersen), exon 53 (NS-065/NCNP-01, golodirsen), and exon 51 (eteplirsen). Eteplirsen (brand name Exondys 51), is the first approved antisense therapy for DMD in the USA, and provides a treatment option for ~14% of all DMD patients, who are amenable to exon 51 skipping. Eteplirsen is granted accelerated approval and marketing authorization by the US Food and Drug Administration (FDA), on the condition that additional postapproval trials show clinical benefit. Permanent exon skipping achieved at the DNA level using clustered regularly interspaced short palindromic repeats (CRISPR) technology holds promise in current preclinical trials for DMD. In hopes of achieving clinical success parallel to DMD, exon skipping and splice modulation are also being studied in other muscular dystrophies, such as Fukuyama congenital muscular dystrophy (FCMD), dysferlinopathy including limb-girdle muscular dystrophy type 2B (LGMD2B), Miyoshi myopathy (MM), and distal anterior compartment myopathy (DMAT), myotonic dystrophy, and merosin-deficient congenital muscular dystrophy type 1A (MDC1A). This chapter also summarizes the development of antisense-mediated exon skipping therapy in diseases such as Usher syndrome, dystrophic epidermolysis bullosa, fibrodysplasia ossificans progressiva (FOP), and allergic diseases.
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11
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Wang M, Wu B, Tucker JD, Shah SN, Lu P, Bollinger LE, Lu Q. Tween 85-Modified Low Molecular Weight PEI Enhances Exon-Skipping of Antisense Morpholino Oligomer In Vitro and in mdx Mice. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 9:120-131. [PMID: 29246291 PMCID: PMC5633364 DOI: 10.1016/j.omtn.2017.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/13/2017] [Accepted: 09/13/2017] [Indexed: 01/16/2023]
Abstract
We investigated a series of Tween 85 modified low molecular weight polyethylenimine (LPEI, 0.8k/1.2k/2.0k)-copolymers (Zs) through simple formulation and covalent conjugation with phosphorodiamidate morpholino oligomer (PMO) for their potential to enhance delivery in vitro and in dystrophic mdx mice. Z polymers significantly enhanced PMO-induced exon-skipping in a GFP reporter-based cell culture system. Application of optimized formulations of Zs with PMO targeted to dystrophin exon 23 demonstrated a significant increase in exon-skipping efficiency in mdx mice. Consistent with our observations in vitro, optimization of molecular size and hydropholic-lipopholic balance (HLB) of polymers are important factors to achieve enhanced PMO delivery in vivo. The best formulation of Zs enhanced PMO delivery with 20- and 6-fold over PMO alone in vitro and in vivo, respectively. Further, chemical conjugation of the polymer and PMO exhibits greater benefit than polymer/PMO simple formulation in PMO delivery efficiency. Observed cytotoxicity of the Zs was lower than Endo-porter and PEI 25k in vitro, and no tissue toxicity was clearly detected with the Zs at the dosage tested. These results indicate the potential of the Zs as effective and safe PMO delivery carriers for treating diseases such as muscular dystrophy.
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Affiliation(s)
- Mingxing Wang
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA.
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA
| | - Jason D Tucker
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA
| | - Sapana N Shah
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA
| | - Lauren E Bollinger
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA
| | - Qilong Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA
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12
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Wang M, Wu B, Shah SN, Lu P, Lu Q. Polyquaternium-mediated delivery of morpholino oligonucleotides for exon-skipping in vitro and in mdx mice. Drug Deliv 2017; 24:952-961. [PMID: 28633548 PMCID: PMC8241187 DOI: 10.1080/10717544.2017.1337827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 12/13/2022] Open
Abstract
Antisense oligonucleotide therapy for Duchenne muscular dystrophy has shown great potential in preclinical and clinical trials, but its therapeutic applications are still limited due to inefficient delivery. In this study, we investigated a few polyquaterniums (PQs) with different size and composition for their potential to improve delivery performance of an antisense phosphorodiamidate morpholino oligomer (PMO) both in vitro and in vivo. The results showed that LuviquatTM series, especially PQ-1 and PQ-3, promoted the exon-skipping efficiency comparable to Endoporter-mediated PMO delivery in vitro. Significant enhancement in skipping dystrophin exon 23 has also been achieved with PQ-3 up to seven-fold when compared to PMO alone in mdx mice. Cytotoxicity of the PQs was lower than Endoporter and PEI 25 K in vitro and muscle damage not clearly detected in vivo under the tested concentrations. These results together demonstrate that the optimization of PQ in molecular size, composition and distribution of positive charges is the key factor to achieve enhanced PMO exon-skipping efficiency. The higher efficiency and lower toxicity endow polyquaternium series as AO delivery enhancing agents for treating muscular dystrophy and other diseases.
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Affiliation(s)
- Mingxing Wang
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Charlotte, NC, United States
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Charlotte, NC, United States
| | - Sapana N Shah
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Charlotte, NC, United States
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Charlotte, NC, United States
| | - Qilong Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Charlotte, NC, United States
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13
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Alternative Splicing in Genetic Diseases: Improved Diagnosis and Novel Treatment Options. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 335:85-141. [PMID: 29305015 DOI: 10.1016/bs.ircmb.2017.07.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Alternative splicing is an important mechanism to regulate gene expression and to expand the repertoire of gene products in order to accommodate an increase in complexity of multicellular organisms. It needs to be precisely regulated, which is achieved via RNA structure, splicing factors, transcriptional regulation, and chromatin. Changes in any of these factors can lead to disease. These may include the core spliceosome, splicing enhancer/repressor sequences and their interacting proteins, the speed of transcription by RNA polymerase II, and histone modifications. While the basic principle of splicing is well understood, it is still very difficult to predict splicing outcome, due to the multiple levels of regulation. Current molecular diagnostics mainly uses Sanger sequencing of exons, or next-generation sequencing of gene panels or the whole exome. Functional analysis of potential splicing variants is scarce, and intronic variants are often not considered. This likely results in underestimation of the percentage of splicing variants. Understanding how sequence variants may affect splicing is not only crucial for confirmation of diagnosis and for genetic counseling, but also for the development of novel treatment options. These include small molecules, transsplicing, antisense oligonucleotides, and gene therapy. Here we review the current state of molecular mechanisms of splicing regulation and how deregulation can lead to human disease, diagnostics to detect splicing variants, and novel treatment options based on splicing correction.
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14
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Niks EH, Aartsma-Rus A. Exon skipping: a first in class strategy for Duchenne muscular dystrophy. Expert Opin Biol Ther 2016; 17:225-236. [PMID: 27936976 DOI: 10.1080/14712598.2017.1271872] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Exon skipping is a therapeutic approach for Duchenne muscular dystrophy (DMD) that has been in development for close to two decades. This approach uses antisense oligonucleotides (AONs) to modulate pre-mRNA splicing of dystrophin transcripts to restore the disrupted DMD reading frame. The approach has moved from in vitro proof of concept studies to the clinical trial phase and marketing authorization applications with regulators. The first AON (eteplirsen) has recently received accelerated approval by the Food and Drug Administration in the US. Areas covered: In this review the authors explain the antisense-mediated exon skipping approach, outline how it needs be tailored for different DMD mutation types and describe the challenges and opportunities for each mutation type. The authors summarize the clinical development of antisense-mediated exon 51 skipping, and discuss methods to improve efficiency. Finally, the authors provide their opinion on current developments and identify topics for future prioritization. Expert opinion: Exon skipping development has been a learning experience for all those involved. Aside from an approved therapy, its development has yielded side benefits including the development of tools for clinical trials and has increased collaboration between academics, patients, industry and regulators.
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Affiliation(s)
- Erik H Niks
- a Department of Neurology , Leiden University Medical Center , Leiden , The Netherlands
| | - Annemieke Aartsma-Rus
- b Department of Human Genetics , Leiden University Medical Center , Leiden , The Netherlands
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Fletcher S, Bellgard MI, Price L, Akkari AP, Wilton SD. Translational development of splice-modifying antisense oligomers. Expert Opin Biol Ther 2016; 17:15-30. [PMID: 27805416 DOI: 10.1080/14712598.2017.1250880] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Antisense nucleic acid analogues can interact with pre-mRNA motifs and influence exon or splice site selection and thereby alter gene expression. Design of antisense molecules to target specific motifs can result in either exon exclusion or exon inclusion during splicing. Novel drugs exploiting the antisense concept are targeting rare, life-limiting diseases; however, the potential exists to treat a wide range of conditions by antisense-mediated splice intervention. Areas covered: In this review, the authors discuss the clinical translation of novel molecular therapeutics to address the fatal neuromuscular disorders Duchenne muscular dystrophy and spinal muscular atrophy. The review also highlights difficulties posed by issues pertaining to restricted participant numbers, variable phenotype and disease progression, and the identification and validation of study endpoints. Expert opinion: Translation of novel therapeutics for Duchenne muscular dystrophy and spinal muscular atrophy has been greatly advanced by multidisciplinary research, academic-industry partnerships and in particular, the engagement and support of the patient community. Sponsors, supporters and regulators are cooperating to deliver new drugs and identify and define meaningful outcome measures. Non-conventional and adaptive trial design could be particularly suited to clinical evaluation of novel therapeutics and strategies to treat serious, rare diseases that may be problematic to study using more conventional clinical trial structures.
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Affiliation(s)
- S Fletcher
- a Centre for Neuromuscular and Neurological Disorders , University of Western Australia , Nedlands , Western Australia , Australia.,b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
| | - M I Bellgard
- b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
| | - L Price
- a Centre for Neuromuscular and Neurological Disorders , University of Western Australia , Nedlands , Western Australia , Australia.,b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
| | - A P Akkari
- b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia.,d Shiraz Pharmaceuticals, Inc , Chapel Hill , NC , USA
| | - S D Wilton
- a Centre for Neuromuscular and Neurological Disorders , University of Western Australia , Nedlands , Western Australia , Australia.,b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
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