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BACKGROUND: Achilles tendon is composed of dense connective tissue and is one of the largest tendons in the body. In veterinary medicine, acute ruptures are associated with impact injury or sharp trauma. Healing of the ruptured tendon is challenging because of poor blood and nerve supply as well as the residual cell population. Platelet-rich plasma (PRP) contains numerous bioactive agents and growth factors and has been utilized to promote healing in bone, soft tissue, and tendons. OBJECTIVE: The purpose of this study was to evaluate the healing effect of PRP injected into the surrounding fascia of the Achilles tendon after allograft in rabbits. METHODS: Donor rabbits (n = 8) were anesthetized and 16 lateral gastrocnemius tendons were fully transected bilaterally. Transected tendons were decellularized and stored at -80°C prior to allograft. The allograft was placed on the partially transected medial gastrocnemius tendon in the left hindlimb of 16 rabbits. The allograft PRP group (n = 8) had 0.3 mL of PRP administered in the tendon and the allograft control group (n = 8) did not receive any treatment. After 8 weeks, rabbits were euthanatized and allograft tendons were transected for macroscopic, biomechanical, and histological assessment. RESULTS: The allograft PRP group exhibited superior macroscopic assessment scores, greater tensile strength, and a histologically enhanced healing process compared to those in the allograft control group. CONCLUSIONS: Our results suggest administration of PRP on an allograft tendon has a positive effect on the healing process in a ruptured Achilles tendon.
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Tendão do Calcâneo , Plasma Rico em Plaquetas , Traumatismos dos Tendões , Coelhos , Animais , Tendão do Calcâneo/cirurgia , Tendão do Calcâneo/lesões , Tendão do Calcâneo/patologia , Traumatismos dos Tendões/terapia , Traumatismos dos Tendões/veterinária , Traumatismos dos Tendões/patologia , Cicatrização , Aloenxertos/patologiaRESUMO
In this study, we investigated the effect of the sulfur content in the NiCl2 precursor on the shape of nickel nanoparticles (Ni-NPs) prepared by chemical vapor synthesis. We obtained spherical Ni-NPs when using anhydrous NiCl2 mixed with NiSO4 or Na2SO4 with a molar ratio of 0.002 as precursors without changing any other process parameters whereas faceted Ni-NPs when using only anhydrous NiCl2 as a precursor. First-principles calculations supported experimental results, which showed that NiSO4-mixed NiCl2 and Na2SO4-mixed NiCl2 precursors favored the growth of spherical NPs.
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The tide gauge measurements from global navigation satellite system reflectometry (GNSS-R) observables are considered to be a promising alternative to the traditional tide gauges in the present days. In the present paper, we deliver a comparative analysis of tide-gauge (TG) measurements retrieved by quasi-zenith satellite system-reflectometry (QZSS-R) and the legacy TG recordings with additional observables from other constellations viz. GPS-R and GLONASS-R. The signal-to-noise ratio data of QZSS (L1, L2, and L5 signals) retrieved at the P109 site of GNSS Earth Observation Network in Japan (37.815° N; 138.281° E; 44.70 m elevation in ellipsoidal height) during 01 October 2019 to 31 December 2019. The results from QZSS observations at L1, L2, and L5 signals show respective correlation coefficients of 0.8712, 0.6998, and 0.8763 with observed TG measurements whereas the corresponding root means square errors were 4.84 cm, 4.26 cm, and 4.24 cm. The QZSS-R signals revealed almost equivalent precise results to that of GPS-R (L1, L2, and L5 signals) and GLONASS-R (L1 and L2 signals). To reconstruct the tidal variability for QZSS-R measurements, a machine learning technique, i.e., kernel extreme learning machine (KELM) is implemented that is based on variational mode decomposition of the parameters. These KELM reconstructed outcomes from QZSS-R L1, L2, and L5 observables provide the respective correlation coefficients of 0.9252, 0.7895, and 0.9146 with TG measurements. The mean errors between the KELM reconstructed outcomes and observed TG measurements for QZSS-R, GPS-R, and GLONASS-R very often lies close to the zero line, confirming that the KELM-based estimates from GNSS-R observations can provide alternative unbiased estimations to the traditional TG measurement. The proposed method seems to be effective, foreseeing a dense tide gauge estimations with the available QZSS-R along with other GNSS-R observables.
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Planeta Terra , Aprendizado de Máquina , Japão , Razão Sinal-RuídoRESUMO
Modern electronic devices, such as smartphones and electric vehicles, require multilayer ceramic capacitors (MLCCs), which comprise highly pure Cu terminations and Ni electrodes. Vapor-phase synthesis (VPS) is a promising method for synthesizing nanoparticles (NPs) with high purity and crystallinity. However, the agglomeration of the NPs occurs during their synthesis, which degrades the performance of the MLCC electrodes owing to several factors, including electrical shorts and low packing density. This paper proposes a coating-assisted VPS to inhibit agglomeration using potassium chloride (KCl) as the coating agent. The agglomeration ratio of the Cu NPs synthesized by in-flight coating with KCl at 950 °C significantly decreased from 48.20% to 3.80%, compared to without KCl coating. Furthermore, X-ray fluorescence and X-ray diffraction analyses confirmed that the KCl coating agent and residual copper chloride were removed by washing with ammonium hydroxide.
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Background: Although the PRISMS study did not demonstrate the benefit of intravenous alteplase administration in patients with mild stroke within 3 h, about 30% of patients presenting with mild symptoms showed unfavorable functional outcomes. We investigated the factors predictive of functional disability at 90 days in patients who were excluded from alteplase administration due to the National Institutes of Health Stroke Scale (NIHSS) scores of 0-5 and a score between 0 and 2 for each NIHSS score item. Methods: All patients were diagnosed with acute ischemic stroke or transient ischemic attack within 4.5 h of admission to a tertiary hospital and did not receive alteplase due to a minor stroke between January 2013 and December 2020. Radiological data and clinical information were collected, including baseline and discharge NIHSS scores and modified Rankin Scale (mRS) scores at 90 days. Early neurological deterioration (END) was defined as an increase of two or more NIHSS scores. We defined moderate motor weakness as a NIHSS limb motor score of more than 3 and defined a favorable outcome as a mRS score at 90 days that was 0 or 1. Results: During the investigation period, 400 patients did not receive alteplase. END occurred significantly more frequently in patients with large artery disease (LAD) than in those with other TOAST classifications. In the multivariate regression analysis, NIHSS per 1-point increase, presenting as moderate motor weakness, and LAD were independent predictors of poor functional outcome (OR, 1.811 NIHSS per 1-point increase; 95% confidence interval [CI], 1.503-2.182; P < 0.0001; OR, 2.173 moderate motor weakness; 95% CI 1.028-4.595; P = 0.042; OR, 2.033 LAD; 95% CI 1.099-3.762; P = 0.024, respectively). Conclusion: Moderate motor weakness presentation and LAD may be important factors associated with poor functional outcomes in patients with acute stroke excluded from alteplase administration due to mild symptoms.
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Nickel (Ni) nanoparticles (NPs) prepared through vapor-phase synthesis (VPS) are preferred for multilayer ceramic capacitor electrodes due to their high purity and crystallinity advantages. Agglomerated Ni NPs are usually generated using VPS but are undesirable because they cause various problems such as low packing density and electrical shorts. This study proposes the use of coating-assisted chemical vapor synthesis (CVS) for agglomerate inhibition using NaCl or KCl as a coating agent. We have found that the agglomeration ratio, 34.40%, for conventional CVS, can be reduced to 4.80% in the proposed method by in-flight coating with KCl at 900 °C by image analysis using field-emission scanning electron microscopy. Furthermore, the X-ray diffraction and X-ray fluorescence analyses confirm that the NaCl and KCl coating agent can be removed by washing with distilled water. We believe that this coating process can be used to inhibit the formation of agglomerates during the CVS of Ni NPs.
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Vibriosis, an illness caused by the Vibrio bacteria species, results in significant economic loss in olive flounder farms. Here we present a novel anti-Vibrio feed vaccine protecting multiple strains of Vibrio pathogens, a universal vaccine effect. The vaccine was generated by engineering Lactococcus lactis BFE920 to express the fusion antigens of Vibrio outer membrane protein K (OmpK) and flagellin B subunit (FlaB). These antigen genes are highly conserved among Vibrio species. Olive flounder (7.1 ± 0.8 g and 140 ± 10 g) were fed the vaccine adsorbed to a regular feed (1 × 107 CFU/g) for one week with a 1-week interval, repeating three times (a triple boost). The vaccinated fish increased the significant levels of antigen-specific antibodies, T cell numbers (CD4-1, CD4-2, and CD8α), cytokine production (T-bet and IFN-γ), and innate immune responses (TLR5M, IL-1ß, and IL-12p40). Also, the survival rates of adult and juvenile fish fed the vaccine were significantly elevated when challenged with V. anguillarum, V. alginolyticus, and V. harveyi. In addition, weight gain rate and feed conversion ratio were improved in vaccinated fish. The feed vaccine protected multiple Vibrio pathogens, a universal vaccine effect, by activating innate and adaptive immune responses. This oral vaccine may be developed as an anti-Vibrio vaccine to protect against a broad spectrum of Vibrio pathogens.
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Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Linguado , Lactococcus lactis/metabolismo , Vibrioses/veterinária , Vibrio/metabolismo , Imunidade Adaptativa , Animais , Vacinas Bacterianas/administração & dosagem , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Imunidade Inata , Probióticos , Vibrio/imunologia , Vibrioses/prevenção & controleRESUMO
Aging is associated with increased prevalence of skeletal and cardiac muscle disorders, such as sarcopenia and cardiac infarction. In this study, we constructed a compendium of purified ginsenoside compounds from Panax ginseng C.A. Meyer, which is a traditional Korean medicinal plant used to treat for muscle weakness. Skeletal muscle progenitor cell-based screening identified three compounds that enhance cell viability, of which 20(R)-ginsenoside Rh2 showed the most robust response. 20(R)-ginsenoside Rh2 increased viability in myoblasts and cardiomyocytes, but not fibroblasts or disease-related cells. The cellular mechanism was identified as downregulation of cyclin-dependent kinase inhibitor 1B (p27Kip1) via upregulation of Akt1/PKB phosphorylation at serine 473, with the orientation of the 20 carbon epimer being crucially important for biological activity. In zebrafish and mammalian models, 20(R)-ginsenoside Rh2 enhanced muscle cell proliferation and accelerated recovery from degeneration. Thus, we have identified 20(R)-ginsenoside Rh2 as a p27Kip1 inhibitor that may be developed as a natural therapeutic for muscle degeneration.
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Ginsenosídeos/farmacologia , Músculo Esquelético/citologia , Infarto do Miocárdio/tratamento farmacológico , Miocárdio/citologia , Panax/química , Saponinas/química , Células-Tronco/metabolismo , Adulto , Animais , Sobrevivência Celular , Ginsenosídeos/química , Ensaios de Triagem em Larga Escala , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Regeneração , Peixe-ZebraRESUMO
In this study, the sintering behaviors of Nb-6Mo-20Si-3Cr (at percentage) in situ composite powders were studied. The Nb alloy powder was fabricated by a hydrogenation-dehydrogenation method, and both the alloy ingot and powders consisted of two phases: An Nb metal phase and the α-Nb5Si3 phase. Consolidation of the alloy powders was performed at 1500, 1600, and 1700 °C using spark plasma sintering, and the microstructures and phases formed at various sintering temperatures were analyzed. Micropores were observed in the compact sintered at 1500 °C due to the lack of complete densification at that temperature. The densification was completed at 1600 °C and the microstructure was slightly coarsened at 1700 °C compared to the microstructure of the compact sintered at 1600 °C. The microstructures prepared by the powder metallurgy method were finer than the microstructure of the ingot prepared by the casting method. The phase formation behavior varied according to the sintering temperature. Specifically, the α-Nb5Si3 phase, which is a stable structure of the Nb5Si3 phase at a low temperature, was transformed to the ß-Nb5Si3 phase (which is stable at a high temperature) with an increasing sintering temperature.
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Insulin and insulin-like growth factor (IGF)-1 signaling in the thyroid are thought to be permissive for the coordinated regulation by thyroid-stimulating hormone (TSH) of thyrocyte proliferation and hormone production. However, the integrated role of insulin receptor (IR) and IGF-1 receptor (IGF-1R) in thyroid development and function has not been explored. Here, we generated thyrocyte-specific IR and IGF-1R double knockout (DTIRKO) mice to precisely evaluate the coordinated functions of these receptors in the thyroid of neonates and adults. Neonatal DTIRKO mice displayed smaller thyroids, paralleling defective folliculogenesis associated with repression of the thyroid-specific transcription factor Foxe1. By contrast, at postnatal day 14, absence of IR and IGF-1R paradoxically induced thyrocyte proliferation, which was mediated by mTOR-dependent signaling pathways. Furthermore, we found elevated production of TSH during the development of follicular hyperplasia at 8 weeks of age. By 50 weeks, all DTIRKO mice developed papillary thyroid carcinoma (PTC)-like lesions that correlated with induction of the ErbB pathway. Taken together, these data define a critical role for IR and IGF-1R in neonatal thyroid folliculogenesis. They also reveal an important reciprocal relationship between IR/IGF-1R and TSH/ErbB signaling in the pathogenesis of thyroid follicular hyperplasia and, possibly, of papillary carcinoma.
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Receptores ErbB/metabolismo , Receptor IGF Tipo 1/deficiência , Receptor de Insulina/deficiência , Câncer Papilífero da Tireoide/metabolismo , Células Epiteliais da Tireoide/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Animais , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Transdução de Sinais , Câncer Papilífero da Tireoide/patologia , Células Epiteliais da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Tireotropina/biossíntese , Tireotropina/metabolismoRESUMO
The pathogenic mutation S163R in C1QTNF5 causes a disorder known as autosomal dominant late-onset retinal degeneration (L-ORD), characterized by the presence of thick extracellular sub-RPE deposits, similar histopathologically to those found in AMD patients. We have previously shown that the S163R C1QTNF5 mutant forms globular aggregates within the RPE in vivo following its AAV-mediated expression in the RPE and exhibits a reversely polarized distribution, being routed toward the basal rather than apical RPE. We show here that when both wild-type and mutant S163R C1QTNF5 are simultaneously delivered subretinally to mouse RPE cells, the mutant impairs the wild-type protein secretion from the RPE, and both proteins are dispersed toward the basal and lateral RPE membrane. This result has mechanistic and therapeutic implications for L-ORD disorder.
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Degeneração Macular/genética , Mutação de Sentido Incorreto , Mutação Puntual , Agregação Patológica de Proteínas/genética , Epitélio Pigmentado da Retina/metabolismo , Animais , Polaridade Celular , Colágeno/química , Colágeno/genética , Colágeno/metabolismo , Dependovirus/genética , Eletrorretinografia , Genes Dominantes , Vetores Genéticos , Humanos , Injeções Intraoculares , Degeneração Macular/metabolismo , Degeneração Macular/patologia , Camundongos , Camundongos Endogâmicos C57BL , Agregação Patológica de Proteínas/patologia , Proteínas Recombinantes/análise , Proteínas Recombinantes/metabolismo , Epitélio Pigmentado da Retina/ultraestrutura , Frações Subcelulares/químicaRESUMO
A new Membrane Film Sensor (MFS) has been developed to measure pH of fluids. MFS comprises a polyelectrolyte multilayer film with uniformly distributed compartments (microchambers) where a fluorescent sensing dye is encapsulated. Fabricated film is sealed onto a polyethylene film for a future use. MFS was applied to report changes in golden pomfret fillet upon its storage at 5⯰C. MFS pH readings were correlated to bacteriological analysis of fish samples. A hike in pH of fish juices happens after 10 days of storage signaling bacterial spoilage of fish. The design of developed MFS allows easy integration with transparent packaging materials for future development of "SMART" packaging sensing food freshness.
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Benzopiranos/química , Técnicas Biossensoriais , Produtos Pesqueiros/análise , Corantes Fluorescentes/química , Embalagem de Alimentos/métodos , Naftóis/química , Rodaminas/química , Composição de Medicamentos/métodos , Produtos Pesqueiros/microbiologia , Inocuidade dos Alimentos/métodos , Humanos , Concentração de Íons de Hidrogênio , Membranas Artificiais , Polieletrólitos/química , Polietileno/química , Polietilenos/química , Compostos de Amônio Quaternário/químicaRESUMO
Adhesion and proliferation of vascular endothelial cells are important parameters in the endothelialization of biomedical devices for vascular applications. Endothelialization is a complex process affected by endothelial cells and their interaction with the extracellular microenvironment. Although numerous approaches are taken to study the influence of the external environment, a systematic investigation of the impact of an engineered microenvironment on endothelial cell processes is needed. This study aims to investigate the influence of topography, initial cell seeding density, and collagen coating on human umbilical vein endothelial cells (HUVECs). Utilizing the MultiARChitecture (MARC) chamber, the effects of various topographies on HUVECs are identified, and those with more prominent effects were further evaluated individually using the MARC plate. Endothelial cell marker expression and monocyte adhesion assay are examined on the HUVEC monolayer. HUVECs on 1.8 µm convex and concave microlens topographies demonstrate the lowest cell adhesion and proliferation, regardless of initial cell seeding density and collagen I coating, and the HUVEC monolayer on the microlens shows the lowest monocyte adhesion. This property of lens topographies would potentially be a useful parameter in designing vascular biomedical devices. The MARC chamber and MARC plate show a great potential for faster and easy pattern identification for various cellular processes.
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Disability in a child not only affects the child but also presents socioeconomic and psychological impacts to the child's family. This study aims to describe the service needs of caregivers of children with disabilities in the state of Penang, Malaysia, and to determine the child and family characteristics predisposing to having more caregiver needs. A cross-sectional survey was conducted between February and June 2013 among caregivers of children aged 0-12 years with disabilities registered with the Penang Department of Social Welfare. Caregivers completed a self-administered mailed questionnaire containing a 20-item Caregiver Needs Scale (CNS). Each item in the CNS was rated on a 5-point Likert scale ranging from 'help not at all needed' to 'help extremely needed'. A total of 273 surveys were available for analysis (response rate 34.0%). The CNS contained four domains. The 'Help getting Information and Services for child' domain had the highest mean score (3.61, 95% CI: 3.46, 3.77) followed by 'Help with Finances' (3.29, 95% CI: 3.13, 3.45) and 'Help Coping with child' (3.11, 95% CI: 2.97, 3.25), while the 'Help getting Childcare' domain had the lowest mean score (2.30, 95% CI: 2.13, 2.47). Multivariate regression analysis identified caregivers of younger children and with more severe disability as having more caregiver needs in all domains. Besides that, caregivers of children with learning disability needed more help getting information and help with coping. Caregivers of children with learning and multiple disabilities needed more help getting childcare compared to children with other disability. Caregivers of Indian ethnicity, who had less than a tertiary education and who themselves had medical problems needed more help with finances. The findings on caregiver needs in this study can help inform planning of family support services for children with disabilities in Penang, Malaysia.
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Cuidadores/estatística & dados numéricos , Crianças com Deficiência/estatística & dados numéricos , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Adaptação Psicológica , Cuidadores/psicologia , Criança , Cuidado da Criança , Estudos Transversais , Feminino , Humanos , Malásia , Masculino , Inquéritos e QuestionáriosRESUMO
Optogenetics methods are rapidly being developed as therapeutic tools for treating neurological diseases, in particular, retinal degenerative diseases. A critical component of the development is testing the safety of the light stimulation used to activate the optogenetic proteins. While the stimulation needs to be sufficient to produce neural responses in the targeted retinal cell class, it also needs to be below photochemical and photothermal limits known to cause ocular damage. The maximal permissible exposure is determined by a variety of factors, including wavelength, exposure duration, visual angle, pupil size, pulse width, pulse pattern, and repetition frequency. In this paper, we develop utilities to systematically and efficiently assess the contributions of these parameters in relation to the limits, following directly from the 2014 American National Standards Institute (ANSI). We also provide an array of stimulus protocols that fall within the bounds of both safety and effectiveness. Additional verification of safety is provided with a case study in rats using one of these protocols.
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Córnea/efeitos da radiação , Optogenética/métodos , Estimulação Luminosa , Retina/efeitos da radiação , Degeneração Retiniana/terapia , Próteses Visuais , Animais , Proteínas do Olho/metabolismo , Humanos , Luz , Ratos , Ratos Long-EvansRESUMO
Poly(vinyl alcohol) hydrogel (PVA) is a widely used material for biomedical devices, yet there is a need to enhance its biological functionality for in vitro and in vivo vascular application. Significance of surface topography in modulating cellular behaviour is increasingly evident. However, hydrogel patterning remains challenging. Using a casting method, planar PVA were patterned with micro-sized features. To achieve higher patterning resolution, nanoimprint lithography with high pressure and temperature was used. In vitro experiment showed enhanced human endothelial cell (EC) density and adhesion on patterned PVA. Additional chemical modification via nitrogen gas plasma on patterned PVA further improved EC density and adhesion. Only EC monolayer grown on plasma modified PVA with 2 µm gratings and 1.8 µm concave lens exhibited expression of vascular endothelial cadherin, indicating EC functionality. Patterning of the luminal surface of tubular hydrogels is not widely explored. The study presents the first method for simultaneous tubular molding and luminal surface patterning of hydrogel. PVA graft with 2 µm gratings showed patency and endothelialization, while unpatterned grafts were occluded after 20 days in rat aorta. The reproducible, high yield and high-fidelity methods enable planar and tubular patterning of PVA and other hydrogels to be used for biomedical applications.
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Células Endoteliais da Veia Umbilical Humana/citologia , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Nanopartículas/química , Nanotecnologia/métodos , Álcool de Polivinil/farmacologia , Animais , Adesão Celular , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Implantes Experimentais , Masculino , Impressão Molecular , Espectroscopia Fotoeletrônica , Gases em Plasma/química , Impressão , Ratos Wistar , Propriedades de SuperfícieRESUMO
Usher syndrome type III (USH3A) is an autosomal recessive disorder caused by mutations in clarin-1 (CLRN1) gene, leading to progressive retinal degeneration and sensorineural deafness. Efforts to develop therapies for preventing photoreceptor cell loss are hampered by the lack of a retinal phenotype in the existing USH3 mouse models and by conflicting reports regarding the endogenous retinal localization of clarin-1, a transmembrane protein of unknown function. In this study, we used an AAV-based approach to express CLRN1 in the mouse retina in order to determine the pattern of its subcellular localization in different cell types. We found that all major classes of retinal cells express AAV-delivered CLRN1 driven by the ubiquitous, constitutive small chicken ß-actin promoter, which has important implications for the design of future USH3 gene therapy studies. Within photoreceptor cells, AAV-expressed CLRN1 is mainly localized at the inner segment region and outer plexiform layer, similar to the endogenous expression of other usher proteins. Subretinal delivery using a full strength viral titer led to significant loss of retinal function as evidenced by ERG analysis, suggesting that there is a critical limit for CLRN1 expression in photoreceptor cells. Taken together, these results suggest that CLRN1 expression is potentially supported by a variety of retinal cells, and the right combination of AAV vector dose, promoter, and delivery method needs to be selected to develop safe therapies for USH3 disorder.
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Terapia Genética , Proteínas de Membrana/biossíntese , Degeneração Retiniana/genética , Síndromes de Usher/genética , Animais , Dependovirus/genética , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Camundongos , Retina/metabolismo , Retina/patologia , Degeneração Retiniana/patologia , Degeneração Retiniana/terapia , Síndromes de Usher/patologia , Síndromes de Usher/terapiaRESUMO
PURPOSE: The mutation S163R in complement C1q tumor necrosis factor-related protein-5 (C1QTNF5) causes an autosomal dominant disorder known as late-onset retinal degeneration (L-ORD). In this study, our goal is to evaluate the consequences of mutant S163R C1QTNF5 expression in mouse RPE following its delivery using an adeno-associated viral (AAV) vector. METHODS: We generated AAV vectors containing either human wild-type C1QTNF5 or mutant S163R C1QTNF5 driven by an RPE-specific BEST1 promoter, and delivered them subretinally into one eye of adult C57BL/6 mice. Transgene expression was detected by immunohistochemistry. Retinal function was assessed by full-field ERG. Pathological changes were further examined by digital fundus imaging and spectral-domain optical coherence tomography (SD-OCT). RESULTS: We show that the AAV-expressed mutant S163R leads to pathological effects similar to some of those found in patients with advanced L-ORD, including RPE thinning, RPE cell loss, and retinal degeneration. In addition, we provide in vivo evidence that mutant S163R C1QTNF5 can form large, transparent, spherical intracellular aggregates throughout the RPE, which are detectable by light microscopy. In contrast to AAV-expressed wild-type C1QTNF5, which is secreted apically from the RPE toward the photoreceptor cells and the outer limiting membrane, the S163R mutant is primarily routed toward the basal side of RPE, where it forms thick, extracellular deposits over time. CONCLUSIONS: Adeno-associated viral-targeted expression of mutant S163R in the RPE represents a useful approach for quickly generating animal models that mimic pathological features of L-ORD and offers the potential to understand disease mechanisms and develop therapeutic strategies.
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Proteínas de Membrana/genética , Epitélio Pigmentado da Retina/patologia , Animais , Bestrofinas , Western Blotting , Proteínas do Olho/genética , Fundo de Olho , Expressão Gênica , Canais Iônicos/genética , Proteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Mutação de Sentido Incorreto , Degeneração Retiniana/genética , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/ultraestrutura , Tomografia de Coerência ÓpticaRESUMO
Mutations in GUCY2D are the cause of Leber congenital amaurosis type 1 (LCA1). GUCY2D encodes retinal guanylate cyclase-1 (retGC1), a protein expressed exclusively in outer segments of photoreceptors and essential for timely recovery from photoexcitation. Recent clinical data show that, despite a high degree of visual disturbance stemming from a loss of cone function, LCA1 patients retain normal photoreceptor architecture, except for foveal cone outer segment abnormalities and, in some patients, foveal cone loss. These results point to the cone-rich central retina as a target for GUCY2D replacement. LCA1 gene replacement studies thus far have been conducted in rod-dominant models (mouse) or with vectors and organisms lacking clinical translatability. Here we investigate gene replacement in the Nrl(-/-) Gucy2e(-/-) mouse, an all-cone model deficient in retGC1. We show that AAV-retGC1 treatment fully restores cone function, cone-mediated visual behavior, and guanylate cyclase activity, and preserves cones in treated Nrl(-/-) Gucy2e(-/-) mice over the long-term. A novel finding was that retinal function could be restored to levels above that in Nrl(-/-) controls, contrasting results in other models of retGC1 deficiency. We attribute this to increased cyclase activity in treated Nrl(-/-) Gucy2e(-/-) mice relative to Nrl(-/-) controls. Thus, Nrl(-/-) Gucy2e(-/-) mice possess an expanded dynamic range in ERG response to gene replacement relative to other models. Lastly, we show that a candidate clinical vector, AAV5-GRK1-GUCY2D, when delivered to adult Nrl(-/-) Gucy2e(-/-) mice, restores retinal function that persists for at least 6 months. Our results provide strong support for clinical application of a gene therapy targeted to the cone-rich, central retina of LCA1 patients.