RESUMEN
Rare genetic diseases preponderantly affect the nervous system causing neurodegeneration to neurodevelopmental disorders. This is the case for both Menkes and Wilson disease, arising from mutations in ATP7A and ATP7B, respectively. The ATP7A and ATP7B proteins localize to the Golgi and regulate copper homeostasis. We demonstrate genetic and biochemical interactions between ATP7 paralogs with the conserved oligomeric Golgi (COG) complex, a Golgi apparatus vesicular tether. Disruption of Drosophila copper homeostasis by ATP7 tissue-specific transgenic expression caused alterations in epidermis, aminergic, sensory, and motor neurons. Prominent among neuronal phenotypes was a decreased mitochondrial content at synapses, a phenotype that paralleled with alterations of synaptic morphology, transmission, and plasticity. These neuronal and synaptic phenotypes caused by transgenic expression of ATP7 were rescued by downregulation of COG complex subunits. We conclude that the integrity of Golgi-dependent copper homeostasis mechanisms, requiring ATP7 and COG, are necessary to maintain mitochondria functional integrity and localization to synapses.SIGNIFICANCE STATEMENT Menkes and Wilson disease affect copper homeostasis and characteristically afflict the nervous system. However, their molecular neuropathology mechanisms remain mostly unexplored. We demonstrate that copper homeostasis in neurons is maintained by two factors that localize to the Golgi apparatus, ATP7 and the conserved oligomeric Golgi (COG) complex. Disruption of these mechanisms affect mitochondrial function and localization to synapses as well as neurotransmission and synaptic plasticity. These findings suggest communication between the Golgi apparatus and mitochondria through homeostatically controlled cellular copper levels and copper-dependent enzymatic activities in both organelles.
Asunto(s)
Cobre/fisiología , Aparato de Golgi/fisiología , Homeostasis/fisiología , Biogénesis de Organelos , Sinapsis/fisiología , Adenosina Trifosfatasas/metabolismo , Animales , Animales Modificados Genéticamente , Línea Celular , Cobre/toxicidad , ATPasas Transportadoras de Cobre/genética , Drosophila , Estimulación Eléctrica , Espacio Extracelular/metabolismo , Femenino , Humanos , Masculino , ARN Interferente Pequeño , Sinapsis/ultraestructuraRESUMEN
BACKGROUND: Despite lower cancer incidence rates, cancer mortality is higher among rural compared to urban dwellers. Patient, provider, and institutional level factors contribute to these disparities. The overarching objective of this study is to leverage the multidisciplinary, multispecialty oncology team from an academic cancer center in order to provide comprehensive cancer care at both the patient and provider levels in rural healthcare centers. Our specific aims are to: 1) evaluate the clinical effectiveness of a multi-level telehealth-based intervention consisting of provider access to molecular tumor board expertise along with patient access to a supportive care intervention to improve cancer care delivery; and 2) identify the facilitators and barriers to future larger scale dissemination and implementation of the multi-level intervention. METHODS: Coordinated by a National Cancer Institute-designated comprehensive cancer center, this study will include providers and patients across several clinics in two large healthcare systems serving rural communities. Using a telehealth-based molecular tumor board, sequencing results are reviewed, predictive and prognostic markers are discussed, and treatment plans are formulated between expert oncologists and rural providers. Simultaneously, the rural patients will be randomized to receive an evidence-based 6-week self-management supportive care program, Cancer Thriving and Surviving, versus an education attention control. Primary outcomes will be provider uptake of the molecular tumor board recommendation and patient treatment adherence. A mixed methods approach guided by the Consolidated Framework for Implementation Research that combines qualitative key informant interviews and quantitative surveys will be collected from both the patient and provider in order to identify facilitators and barriers to implementing the multi-level intervention. DISCUSSION: The proposed study will leverage information technology-enabled, team-based care delivery models in order to deliver comprehensive, coordinated, and high-quality cancer care to rural and/or underserved populations. Simultaneous attention to institutional, provider, and patient level barriers to quality care will afford the opportunity for us to broadly share oncology expertise and develop dissemination and implementation strategies that will enhance the cancer care delivered to patients residing within underserved rural communities. TRIAL REGISTRATION: Clinicaltrials.gov , NCT04758338 . Registered 17 February 2021 - Retrospectively registered, http://www.clinicaltrials.gov/.
Asunto(s)
Accesibilidad a los Servicios de Salud , Neoplasias/genética , Neoplasias/terapia , Salud Rural , Población Rural , Telemedicina , Adulto , Instituciones Oncológicas , Hospitales Rurales , Humanos , Consentimiento Informado , Área sin Atención Médica , Cooperación del Paciente , Educación del Paciente como Asunto , Mejoramiento de la Calidad , Automanejo , Telemedicina/métodos , Telemedicina/organización & administración , Telemedicina/normas , Estados UnidosRESUMEN
Genetic and environmental factors, such as metals, interact to determine neurological traits. We reasoned that interactomes of molecules handling metals in neurons should include novel metal homeostasis pathways. We focused on copper and its transporter ATP7A because ATP7A null mutations cause neurodegeneration. We performed ATP7A immunoaffinity chromatography and identified 541 proteins co-isolating with ATP7A. The ATP7A interactome concentrated gene products implicated in neurodegeneration and neurodevelopmental disorders, including subunits of the Golgi-localized conserved oligomeric Golgi (COG) complex. COG null cells possess altered content and subcellular localization of ATP7A and CTR1 (SLC31A1), the transporter required for copper uptake, as well as decreased total cellular copper, and impaired copper-dependent metabolic responses. Changes in the expression of ATP7A and COG subunits in Drosophila neurons altered synapse development in larvae and copper-induced mortality of adult flies. We conclude that the ATP7A interactome encompasses a novel COG-dependent mechanism to specify neuronal development and survival.