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Vila MC, Klimek MB, Novak JS, Rayavarapu S, Uaesoontrachoon K, Boehler JF, Fiorillo AA, Hogarth MW, Zhang A, Shaughnessy C, Gordish-Dressman H, Burki U, Straub V, Lu QL, Partridge TA, Brown KJ, Hathout Y, van den Anker J, Hoffman EP, Nagaraju K. Elusive sources of variability of dystrophin rescue by exon skipping. Skelet Muscle 2015; 5:44. [PMID: 26634117 PMCID: PMC4667482 DOI: 10.1186/s13395-015-0070-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 11/24/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Systemic delivery of anti-sense oligonucleotides to Duchenne muscular dystrophy (DMD) patients to induce de novo dystrophin protein expression in muscle (exon skipping) is a promising therapy. Treatment with Phosphorodiamidate morpholino oligomers (PMO) lead to shorter de novo dystrophin protein in both animal models and DMD boys who otherwise lack dystrophin; however, restoration of dystrophin has been observed to be highly variable. Understanding the factors causing highly variable induction of dystrophin expression in pre-clinical models would likely lead to more effective means of exon skipping in both pre-clinical studies and human clinical trials. METHODS In the present study, we investigated possible factors that might lead to the variable success of exon skipping using morpholino drugs in the mdx mouse model. We tested whether specific muscle groups or fiber types showed better success than others and also correlated residual PMO concentration in muscle with the amount of de novo dystrophin protein 1 month after a single high-dose morpholino injection (800 mg/kg). We compared the results from six muscle groups using three different methods of dystrophin quantification: immunostaining, immunoblotting, and mass spectrometry assays. RESULTS The triceps muscle showed the greatest degree of rescue (average 38±28 % by immunostaining). All three dystrophin detection methods were generally concordant for all muscles. We show that dystrophin rescue occurs in a sporadic patchy pattern with high geographic variability across muscle sections. We did not find a correlation between residual morpholino drug in muscle tissue and the degree of dystrophin expression. CONCLUSIONS While we found some evidence of muscle group enhancement and successful rescue, our data also suggest that other yet-undefined factors may underlie the observed variability in the success of exon skipping. Our study highlights the challenges associated with quantifying dystrophin in clinical trials where a single small muscle biopsy is taken from a DMD patient.
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Affiliation(s)
- Maria Candida Vila
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Margaret Benny Klimek
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - James S Novak
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Sree Rayavarapu
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Kitipong Uaesoontrachoon
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Jessica F Boehler
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Alyson A Fiorillo
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Marshall W Hogarth
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Aiping Zhang
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Conner Shaughnessy
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA
| | - Heather Gordish-Dressman
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Umar Burki
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases at Newcastle, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases at Newcastle, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Neuromuscular/ALS Center, Department of Neurology, Carolinas Medical Center, Charlotte, NC USA
| | - Terence A Partridge
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Kristy J Brown
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Yetrib Hathout
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - John van den Anker
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Center for Translational Science, Children's National Health System, Washington, DC, USA
| | - Eric P Hoffman
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Kanneboyina Nagaraju
- Research Center for Genetic Medicine, Children's National Health System, 111 Michigan Avenue N.W., Washington, DC, 20010 USA.,Institute of Biomedical Sciences, The George Washington University, Washington, DC, USA
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Zhang A, Uaesoontrachoon K, Shaughnessy C, Das JR, Rayavarapu S, Brown KJ, Ray PE, Nagaraju K, van den Anker JN, Hoffman EP, Hathout Y. The use of urinary and kidney SILAM proteomics to monitor kidney response to high dose morpholino oligonucleotides in the mdx mouse. Toxicol Rep 2015. [PMID: 26213685 PMCID: PMC4512206 DOI: 10.1016/j.toxrep.2015.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Phosphorodiamidate morpholino oligonucleotides (PMO) are used as a promising exon-skipping gene therapy for Duchenne Muscular Dystrophy (DMD). One potential complication of high dose PMO therapy is its transient accumulation in the kidneys. Therefore new urinary biomarkers are needed to monitor this treatment. Here, we carried out a pilot proteomic profiling study using stable isotope labeling in mammals (SILAM) strategy to identify new biomarkers to monitor the effect of PMO on the kidneys of the dystrophin deficient mouse model for DMD (mdx-23). We first assessed the baseline renal status of the mdx-23 mouse compared to the wild type (C57BL10) mouse, and then followed the renal outcome of mdx-23 mouse treated with a single high dose intravenous PMO injection (800 mg/kg). Surprisingly, untreated mdx-23 mice showed evidence of renal injury at baseline, which was manifested by albuminuria, increased urine output, and changes in established urinary biomarker of acute kidney injury (AKI). The PMO treatment induced further transient renal injury, which peaked at 7 days, and returned to almost the baseline status at 30 days post-treatment. In the kidney, the SILAM approach followed by western blot validation identified changes in Meprin A subunit alpha at day 2, then returned to normal levels at day 7 and 30 after PMO injection. In the urine, SILAM approach identified an increase in Clusterin and γ-glutamyl transpeptidase 1 as potential candidates to monitor the transient renal accumulation of PMO. These results, which were confirmed by Western blots or ELISA, demonstrate the value of the SILAM approach to identify new candidate biomarkers of renal injury in mdx-23 mice treated with high dose PMO. Chemical compounds studied in this article: Phosphorodiamidate morpholino (PubChem CID: 22140692); isoflurane (PubChem CID: 3763); formic acid (PubChem CID: 284); acetonitrile (PubChem CID: 6342); acetone (PubChem CID: 180); methanol (PubChem CID: 887).
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Affiliation(s)
- Aiping Zhang
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Kitipong Uaesoontrachoon
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Conner Shaughnessy
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Jharna R Das
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Sree Rayavarapu
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Kristy J Brown
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Patricio E Ray
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Kanneboyina Nagaraju
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - John N van den Anker
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Eric P Hoffman
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
| | - Yetrib Hathout
- The Centers for Genetic Medicine Research and Translational Science, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA
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