RESUMO
Gene therapy for genetic hearing loss is an emerging therapeutic modality for hearing restoration. However, the approach has not yet been translated into clinical application. To further develop inner-ear gene therapy, we engineered a novel mouse model bearing a human mutation in the transmembrane channel-1 gene (Tmc1) and characterized the auditory phenotype of the mice. TMC1 forms the mechanosensory transduction channel in mice and humans and is necessary for auditory function. We found that mice harboring the equivalent of the human p.N199I mutation (p.N193I) had profound congenital hearing loss due to loss of hair cell sensory transduction. Next, we optimized and screened viral payloads packaged into AAV9-PHP.B capsids. The vectors were injected into the inner ears of Tmc1Δ/Δ mice and the new humanized Tmc1-p.N193I mouse model. Auditory brainstem responses (ABRs), distortion product otoacoustic emissions (DPOAEs), cell survival, and biodistribution were evaluated in the injected mice. We found broad-spectrum, durable recovery of auditory function in Tmc1-p.N193I mice injected with AAV9-PHP.B-CB6-hTMC1-WPRE. ABR and DPOAE thresholds were equivalent to those of wild-type mice across the entire frequency range. Biodistribution analysis revealed viral DNA/RNA in the contralateral ear, brain, and liver but no overt toxicity. We conclude that the AAV9-PHP.B-CB6-hTMC1-WPRE construct may be suitable for further development as a gene therapy reagent for treatment of humans with genetic hearing loss due to recessive TMC1 mutations.
Assuntos
Surdez , Perda Auditiva , Animais , Surdez/genética , Modelos Animais de Doenças , Terapia Genética , Perda Auditiva/genética , Perda Auditiva/terapia , Perda Auditiva Neurossensorial , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Distribuição TecidualRESUMO
BACKGROUND: Fatigue is one of the most prevalent non-motor symptoms of Parkinson's disease (PD). Research is hampered by imprecise terminology and the lack of case definition criteria. OBJECTIVES: To elicit the experiences of persons living with PD-related fatigue and provide ecological validation for case definition criteria. METHODS: Qualitative interviews were conducted with 22 individuals and 4 focus groups, and analyzed using an inductive qualitative method. RESULTS: Six core themes emerged: (i) difficulty initiating and completing important tasks; (ii) desire for others to understand their fatigue experience; (iii) heterogeneity of experiences and descriptions of fatigue; (iv) complex relationships with other non-motor symptoms; (v) variable self-management strategies; and (vi) general alignment with proposed case definition criteria. CONCLUSIONS: PD-related fatigue impacts function, is subjectively distinguishable from other non-motor symptoms, has heterogeneous descriptions, and may be mitigated by various self-management strategies. Proposed case definition criteria appear ecologically valid and warrant further optimization and testing.
