RESUMEN
Duchenne muscular dystrophy (DMD) is primarily caused by out-of-frame deletions in the dystrophin gene. Exon skipping using phosphorodiamidate morpholino oligomers (PMOs) converts out-of-frame to in-frame mutations, producing partially functional dystrophin. Four single-exon skipping PMOs are approved for DMD but treat only 8 to 14% of patients each, and some exhibit poor efficacy. Alternatively, exons 45 to 55 skipping could treat 40 to 47% of all patients and is associated with improved clinical outcomes. Here, we report the development of peptide-conjugated PMOs for exons 45 to 55 skipping. Experiments with immortalized patient myotubes revealed that exons 45 to 55 could be skipped by targeting as few as five exons. We also found that conjugating DG9, a cell-penetrating peptide, to PMOs improved single-exon 51 skipping, dystrophin restoration, and muscle function in hDMDdel52;mdx mice. Local administration of a minimized exons 45 to 55-skipping DG9-PMO mixture restored dystrophin production. This study provides proof of concept toward the development of a more economical and effective exons 45 to 55-skipping DMD therapy.
Asunto(s)
Exones , Distrofia Muscular de Duchenne/terapia , Oligonucleótidos Antisentido/uso terapéutico , Péptidos/química , Animales , Distrofina/biosíntesis , Terapia Genética , Humanos , Ratones , Ratones Endogámicos mdx , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Miocardio/metabolismo , Oligonucleótidos Antisentido/genéticaRESUMEN
BACKGROUND: Surgeon-industry collaboration is a key driver of advancement in surgical technology and practice. Disclosures of financial relationships between investigators and industries are important to ensure transparent and critical evaluation of literature. METHODS: All American cardiothoracic (CT) surgeons who published in three major CT surgery journals in 2019 were identified. Whether these surgeons disclosed any conflicts of interest was recorded and compared to actual payments received within 5 years of publication as reported by the Centers for Medicare and Medicaid Services data. RESULTS: In the study period, there were 1079 unique manuscripts involving 885 American CT surgeons as authors, which combined for 2719 author instances. Of these, 96.2% of authors (851 of 885) received payments from companies. The authors who received payments produced 2651 author instances (97.4%). Financial disclosure was reported in only 11.4% (301 of 2651) of these instances. In total, 851 surgeons received more than $187 million over 5 years, with the highest-paid surgeon receiving an average of over $5.9 million per year. The largest individual payments were from "Associated Research Funding," with over $115 million being paid to 277 surgeons over 5 years. The top paying company issued over $96.5 million to American CT surgeons over 5 years. CONCLUSIONS: Nearly all the reviewed publications in three top CT surgery journals were by surgeons who received payments from companies, but very few of these payments were recorded as potential conflicts of interest. A more consistent and robust policy of COI disclosure is needed to reduce perceptions of bias.
Asunto(s)
Especialidades Quirúrgicas , Cirujanos , Anciano , Humanos , Estados Unidos , Revelación , Conflicto de Intereses , MedicareRESUMEN
Mutations in the dystrophin (DMD) gene and consequent loss of dystrophin cause Duchenne muscular dystrophy (DMD). A promising therapy for DMD, single-exon skipping using antisense phosphorodiamidate morpholino oligomers (PMOs), currently confronts major issues in that an antisense drug induces the production of functionally undefined dystrophin and may not be similarly efficacious among patients with different mutations. Accordingly, the applicability of this approach is limited to out-of-frame mutations. Here, using an exon-skipping efficiency predictive tool, we designed three different PMO cocktail sets for exons 45-55 skipping aiming to produce a dystrophin variant with preserved functionality as seen in milder or asymptomatic individuals with an in-frame exons 45-55 deletion. Of them, the most effective set was composed of select PMOs that each efficiently skips an assigned exon in cell-based screening. These combinational PMOs fitted to different deletions of immortalized DMD patient muscle cells significantly induced exons 45-55 skipping with removing 3, 8, or 10 exons and dystrophin restoration as represented by western blotting. In vivo skipping of the maximum 11 human DMD exons was confirmed in humanized mice. The finding indicates that our PMO set can be used to create mutation-tailored cocktails for exons 45-55 skipping and treat over 65% of DMD patients carrying out-of-frame or in-frame deletions.
Asunto(s)
Empalme Alternativo , Distrofina/genética , Exones , Regulación de la Expresión Génica , Morfolinos/genética , Distrofia Muscular de Duchenne/genética , Mutación , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Transgénicos , Distrofia Muscular de Duchenne/diagnóstico , Fenotipo , Eliminación de SecuenciaAsunto(s)
Conflicto de Intereses , Revelación , Cirugía Torácica , Revelación/ética , Humanos , Estados Unidos , Cirujanos/psicología , Cirujanos/éticaRESUMEN
Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder due to the lack of dystrophin production. The disease is characterized by muscle wasting, with the most common causes of death being respiratory failure or heart failure. Recently, exon skipping using a phosphorodiamidate morpholino oligomer (PMO) is used as an FDA approved treatment for DMD. Peptide-conjugated PMOs (PPMOs) are used to increase exon skipping efficacy in the heart and are a promising therapy for DMD. Researchers have previously relied on high-performance liquid chromatography (HPLC) or liquid chromatography-mass spectrometry (LC/MS) methods for detecting PPMO uptake, but an enzyme-linked immunosorbent assay (ELISA) has been shown to have greater sensitivity. Here, we present methodologies to determine the uptake efficiency of a PPMO into the heart and efficacy of exon 51 skipping by a PPMO injected retro-orbitally into a humanized DMD mouse model via ELISA and RT-PCR, respectively.