Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 14.756
Filtrar
1.
Yakugaku Zasshi ; 140(10): 1235-1242, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999202

RESUMO

The central nervous system (CNS) is segregated from the circulating blood and peripheral tissues by endothelial and epithelial barriers. To overcome refractory CNS diseases, it is important to understand the membrane transport systems of drugs and the endogenous compounds that relate to the pathogenesis of CNS diseases at these barriers. The endothelial barrier in the brain is the blood-brain barrier (BBB). Our studies clarified the efflux transport of prostaglandin E2 (PGE2), a modulator of neural excitation and inflammatory responses, across the BBB via plasma membrane transporters such as organic anion transporter 3 (Oat3) and multidrug resistance-associated protein 4 (Mrp4). This efflux transport was attenuated by peripheral inflammation or cerebral treatment with neuroexcitatory l-glutamate, suggesting that BBB-mediated PGE2 elimination was altered under several pathological conditions. We also examined excitatory amino acid transporter (EAAT) 1 and 3 as l-glutamate efflux transporters of the inner blood-retinal barrier (BRB) and blood-cerebrospinal barrier. It was considered that these efflux membrane transporters participated in the homeostasis of neuroexcitatory and neuroinflammatory responses in the brain and retina. Moreover, we identified connexin 43 (Cx43) hemichannels as a new membrane transport system that is activated under pathological conditions and recognizes several monocarboxylate drugs, such as valproate. As it is expected that the action of these membrane transporters across the CNS barriers is of great importance in understanding the pathology of various neuroexcitatory diseases, our studies should contribute to the establishment of therapeutic strategies for refractory CNS diseases.


Assuntos
Transporte Biológico , Barreira Hematoencefálica/metabolismo , Barreira Hematorretiniana/metabolismo , Encéfalo/metabolismo , Doenças do Sistema Nervoso Central/etiologia , Doenças do Sistema Nervoso Central/metabolismo , Desenvolvimento de Medicamentos , Proteínas de Membrana Transportadoras/metabolismo , Retina/metabolismo , Animais , Doenças do Sistema Nervoso Central/tratamento farmacológico , Conexina 43/metabolismo , Dinoprostona/metabolismo , Transportador 1 de Aminoácido Excitatório/metabolismo , Ácido Glutâmico/metabolismo , Humanos , Camundongos , Terapia de Alvo Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo
2.
Proc Natl Acad Sci U S A ; 117(32): 19599-19603, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719136

RESUMO

We have used recent measurements of mammalian cone light responses and voltage-gated currents to calculate cone ATP utilization and compare it to that of rods. The largest expenditure of ATP results from ion transport, particularly from removal of Na+ entering outer segment light-dependent channels and inner segment hyperpolarization-activated cyclic nucleotide-gated channels, and from ATP-dependent pumping of Ca2+ entering voltage-gated channels at the synaptic terminal. Single cones expend nearly twice as much energy as single rods in darkness, largely because they make more synapses with second-order retinal cells and thus must extrude more Ca2+ In daylight, cone ATP utilization per cell remains high because cones never remain saturated and must continue to export Na+ and synaptic Ca2+ even in bright illumination. In mouse and human retina, rods greatly outnumber cones and consume more energy overall even in background light. In primates, however, the high density of cones in the fovea produces a pronounced peak of ATP utilization, which becomes particularly prominent in daylight and may make this part of the retina especially sensitive to changes in energy availability.


Assuntos
Retina/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , GMP Cíclico/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Fóvea Central/citologia , Fóvea Central/metabolismo , Humanos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Ativação do Canal Iônico , Luz , Camundongos , Terminações Pré-Sinápticas/metabolismo , Retina/citologia , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Sódio/metabolismo
3.
Nat Commun ; 11(1): 3481, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661226

RESUMO

Color vision is essential for an animal's survival. It starts in the retina, where signals from different photoreceptor types are locally compared by neural circuits. Mice, like most mammals, are dichromatic with two cone types. They can discriminate colors only in their upper visual field. In the corresponding ventral retina, however, most cones display the same spectral preference, thereby presumably impairing spectral comparisons. In this study, we systematically investigated the retinal circuits underlying mouse color vision by recording light responses from cones, bipolar and ganglion cells. Surprisingly, most color-opponent cells are located in the ventral retina, with rod photoreceptors likely being involved. Here, the complexity of chromatic processing increases from cones towards the retinal output, where non-linear center-surround interactions create specific color-opponent output channels to the brain. This suggests that neural circuits in the mouse retina are tuned to extract color from the upper visual field, aiding robust detection of predators and ensuring the animal's survival.


Assuntos
Visão de Cores/fisiologia , Retina/fisiologia , Animais , Eletroporação , Feminino , Luz , Masculino , Camundongos , Retina/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Campos Visuais/fisiologia , Vias Visuais/fisiologia
4.
Nat Commun ; 11(1): 3328, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620864

RESUMO

Genes encoding cell-surface proteins control nervous system development and are implicated in neurological disorders. These genes produce alternative mRNA isoforms which remain poorly characterized, impeding understanding of how disease-associated mutations cause pathology. Here we introduce a strategy to define complete portfolios of full-length isoforms encoded by individual genes. Applying this approach to neural cell-surface molecules, we identify thousands of unannotated isoforms expressed in retina and brain. By mass spectrometry we confirm expression of newly-discovered proteins on the cell surface in vivo. Remarkably, we discover that the major isoform of a retinal degeneration gene, CRB1, was previously overlooked. This CRB1 isoform is the only one expressed by photoreceptors, the affected cells in CRB1 disease. Using mouse mutants, we identify a function for this isoform at photoreceptor-glial junctions and demonstrate that loss of this isoform accelerates photoreceptor death. Therefore, our isoform identification strategy enables discovery of new gene functions relevant to disease.


Assuntos
Variação Genética , Proteínas de Membrana/genética , Células Fotorreceptoras de Vertebrados/metabolismo , Isoformas de RNA/genética , Retina/metabolismo , Degeneração Retiniana/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Isoformas de RNA/metabolismo , Retina/citologia , Retina/crescimento & desenvolvimento , Degeneração Retiniana/metabolismo , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
5.
Gene ; 760: 144992, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721474

RESUMO

BACKGROUND AND AIM: Diabetic retinopathy is a severe diabetic complication and a major cause of blindness. In this study, we explored the role of circ_0001879 in retinal vascular dysfunction under diabetic conditions. METHODS: Human retinal microvascular endothelial cells (HRMECs) were divided into normal glucose group (NG, 5.5 mmol/L d-glucose), high glucose group (HG, 25 mmol/L d-glucose), and osmotic control group (5.5 mmol/L d-glucose + 19.5 mmol/L mannitol). The expression of circ_0001879 and miR-30-3p was assessed via qRT-PCR. The circ_0001879/miR-30-3p roles in retinal vascular dysfunction were investigated through Cell Counting Kit-8 and Transwell assay. Bioinformatics analysis and luciferase reporter assays were applied to examine interactions between circ_0001879 and miR-30-3p in HRMECs. RESULTS: The relative circ_0001879 expression was remarkably increased in diabetic retinas group than that in the control group. Silencing circ_0001879 suppressed the proliferation and migration of HRMECs under high-glucose conditions. In addition, circ_0001879 acted as a binding platform and miRNA sponge for miR-30-3p. Circ_0001879 modulated the function of HRMECs via targeting miR-30-3p. CONCLUSION: Silencing circ_0001879 inhibited the proliferation and migration of HRMECs under high-glucose conditions via modulating miR-30-3p, which might shed new light on a novel potentially marker and molecular therapeutic target for diabetic retinopathy.


Assuntos
Retinopatia Diabética/patologia , Glucose/administração & dosagem , MicroRNAs/genética , Vasos Retinianos/patologia , Animais , Linhagem Celular , Movimento Celular/genética , Proliferação de Células/genética , Retinopatia Diabética/genética , Retinopatia Diabética/metabolismo , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Glucose/metabolismo , Humanos , Masculino , MicroRNAs/metabolismo , Ratos , Ratos Sprague-Dawley , Retina/efeitos dos fármacos , Retina/metabolismo , Retina/patologia , Vasos Retinianos/efeitos dos fármacos , Vasos Retinianos/metabolismo
6.
Med Sci (Paris) ; 36(6-7): 616-625, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32614313

RESUMO

Iron has a fundamental role for cell physiology and especially in retina as a cofactor of many pathways of the visual transduction. A tightly regulated homeostasis avoids the accumulation of prooxidant and proinflammatory free iron. A dysfunction of iron retinal homeostasis is associated with many genetic or age-related degenerative diseases such as age-related macular degeneration (AMD). Here, we describe various mechanisms reported during AMD, enhanced by iron accumulation and its homeostasis dysregulation. We have investigated a local treatment with transferrin, the natural iron carrier, to control these pathological pathways and iron dysfunction, without side effects. Iron has a central role in pathogenesis of AMD and is a target for futures therapies.


Assuntos
Ferro/fisiologia , Degeneração Macular/etiologia , Homeostase/genética , Humanos , Ferro/metabolismo , Degeneração Macular/genética , Degeneração Macular/metabolismo , Degeneração Macular/terapia , Redes e Vias Metabólicas/genética , Retina/metabolismo , Retina/patologia , Terapias em Estudo/métodos , Terapias em Estudo/tendências , Transferrina/genética , Transferrina/fisiologia
7.
Nat Commun ; 11(1): 3173, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576823

RESUMO

Central nervous system ischemic injury features neuronal dysfunction, inflammation and breakdown of vascular integrity. Here we show that activation of endothelial caspase-9 after hypoxia-ischemia is a critical event in subsequent dysfunction of the blood-retina barrier, using a panel of interrelated ophthalmic in vivo imaging measures in a mouse model of retinal vein occlusion (RVO). Rapid nonapoptotic activation of caspase-9 and its downstream effector caspase-7 in endothelial cells promotes capillary ischemia and retinal neurodegeneration. Topical eye-drop delivery of a highly selective caspase-9 inhibitor provides morphological and functional retinal protection. Inducible endothelial-specific caspase-9 deletion phenocopies this protection, with attenuated retinal edema, reduced inflammation and preserved neuroretinal morphology and function following RVO. These results reveal a non-apoptotic function of endothelial caspase-9 which regulates blood-retina barrier integrity and neuronal survival, and identify caspase-9 as a therapeutic target in neurovascular disease.


Assuntos
Caspase 9/metabolismo , Hipóxia/metabolismo , Isquemia/metabolismo , Oclusão da Veia Retiniana/metabolismo , Lesões do Sistema Vascular/metabolismo , Animais , Barreira Hematorretiniana/metabolismo , Caspase 7/metabolismo , Caspase 9/efeitos dos fármacos , Caspase 9/genética , Morte Celular , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Feminino , Predisposição Genética para Doença/genética , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Coelhos , Retina/metabolismo , Retina/patologia , Oclusão da Veia Retiniana/tratamento farmacológico , Oclusão da Veia Retiniana/patologia , Lesões do Sistema Vascular/patologia
8.
Life Sci ; 256: 117935, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32526286

RESUMO

AIMS: Retinal ischemia/reperfusion (I/R) injury is common in the development of ophthalmic diseases and potentially causes blindness. In present study, the aim is to investigate the possible protective effects of puerarin on retinal I/R. MAIN METHODS: Retinal I/R injury was conducted on the left eyes of male Sprague Dawley rats, which were subsequently received treatment with puerarin. After administration, retinal I/R-induced apoptosis, oxidative stress and inflammatory responses were detected. Meanwhile, we purified retinal ganglion cells (RGCs) from 7-day-old rats. After subjected RGCs to oxygen and glucose deprivation/reoxygenation (OGD/R), apoptosis and TLR4/NLRP3 inflammasome activation in RGCs were detected. KEY FINDINGS: Puerarin prominently suppressed apoptosis, alleviated oxidative stress and suppressed TLR4/NLRP3 inflammasome activation in rats with retinal I/R injury. Consistent with our in vivo study, we found puerarin ameliorated retinal I/R injury through suppressing apoptosis and TLR4/NLRP3 inflammasome activation in RGCs. SIGNIFICANCE: Our findings reveal that puerarin plays a protective role against retinal I/R injury by alleviating RGC damage, and is beneficial for the treatment of I/R injury-caused ophthalmic diseases.


Assuntos
Isoflavonas/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Doenças Retinianas/tratamento farmacológico , Células Ganglionares da Retina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Humanos , Inflamassomos/metabolismo , Masculino , Modelos Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Retina/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/metabolismo
9.
PLoS One ; 15(6): e0234744, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32542037

RESUMO

Developmental processes require strict regulation of proliferation, differentiation and patterning for the generation of final organ size. Aberrations in these fundamental events are critically important in tumorigenesis and cancer progression. Salt inducible kinases (Siks) are evolutionarily conserved genes involved in diverse biological processes, including salt sensing, metabolism, muscle, cartilage and bone formation, but their role in development remains largely unknown. Recent findings implicate Siks in mitotic control, and in both tumor suppression and progression. Using a tumor model in the Drosophila eye, we show that perturbation of Sik function exacerbates tumor-like tissue overgrowth and metastasis. Furthermore, we show that both Drosophila Sik genes, Sik2 and Sik3, function in eye development processes. We propose that an important target of Siks may be the Notch signaling pathway, as we demonstrate genetic interaction between Siks and Notch pathway members. Finally, we investigate Sik expression in the developing retina and show that Sik2 is expressed in all photoreceptors, basal to cell junctions, while Sik3 appears to be expressed specifically in R3/R4 cells in the developing eye. Combined, our data suggest that Sik genes are important for eye tissue specification and growth, and that their dysregulation may contribute to tumor formation.


Assuntos
Drosophila/enzimologia , Drosophila/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/metabolismo , Receptores Notch/metabolismo , Retina/crescimento & desenvolvimento , Animais , Drosophila/metabolismo , Ligação Proteica , Retina/metabolismo
10.
Am J Pathol ; 190(9): 1971-1981, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32590003

RESUMO

Leakage of retinal blood vessels, which is an essential element of diabetic retinopathy, is driven by chronic elevation of vascular endothelial growth factor (VEGF). VEGF quickly relaxes the endothelial cell barrier by triggering signaling events that post-translationally modify pre-existing components of intercellular junctions. VEGF also changes expression of genes that are known to regulate barrier function. Our goal was to identify effectors by which VEGF and anti-VEGF control the endothelial cell barrier in cells that were chronically exposed to VEGF (hours instead of minutes). The duration of VEGF exposure influenced both barrier relaxation and anti-VEGF-mediated closure. Most VEGF-induced changes in gene expression were not reversed by anti-VEGF. Those that were constitute VEGF effectors that are targets of anti-VEGF. Pursuit of such candidates revealed that VEGF used multiple, nonredundant effectors to relax the barrier in cells that were chronically exposed to VEGF. One such effector was angiotensin-converting enzyme, which is a member of the renin-angiotensin-aldosterone system (RAAS). Pharmacologically antagonizing either the angiotensin-converting enzyme or the receptor for angiotensin II attenuated VEGF-mediated relaxation of the barrier. Finally, activating the RAAS reduced the efficacy of anti-VEGF. These discoveries provide a plausible mechanistic explanation for the long-standing appreciation that RAAS inhibitors are beneficial for patients with diabetic retinopathy and suggest that antagonizing the RAAS improves patients' responsiveness to anti-VEGF.


Assuntos
Retinopatia Diabética/metabolismo , Células Endoteliais/metabolismo , Sistema Renina-Angiotensina/fisiologia , Retina/metabolismo , Vasos Retinianos/metabolismo , Antagonistas de Receptores de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Permeabilidade Capilar/efeitos dos fármacos , Células Cultivadas , Humanos , Vasos Retinianos/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
PLoS One ; 15(5): e0232779, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365083

RESUMO

Apoptosis of neurovascular cells, including astroglial cells, contributes to the pathogenesis of diseases in which neurovascular disruption plays a central role. Bim is a pro-apoptotic protein that modulates not only apoptosis but also various cellular functions such as migration and extracellular matrix protein expression. Astroglial cells act as an intermediary between neural and vascular cells facilitating retinal vascular development and remodeling while maintaining normal vascular function and neuronal integrity. We previously showed that Bim deficient (Bim -/-) mice were protected from hyperoxia mediated vessel obliteration and ischemia-mediated retinal neovascularization. However, the underlying mechanisms and more specifically the role Bim expression in astroglial cells play remains elusive. Here, using retinal astroglial cells prepared from wild-type and Bim -/- mice, we determined the impact of Bim expression in retinal astroglial cell function. We showed that astroglial cells lacking Bim expression demonstrate increased VEGF expression and altered matricellular protein production including increased expression of thrombospondin-2 (TSP2), osteopontin and SPARC. Bim deficient astroglial cells also exhibited altered proliferation, migration, adhesion to various extracellular matrix proteins and increased expression of inflammatory mediators. Thus, our data emphasizes the importance of Bim expression in retinal astroglia cell autonomous regulatory mechanisms, which could influence neurovascular function.


Assuntos
Astrócitos/metabolismo , Proteína 11 Semelhante a Bcl-2/genética , Inflamação/genética , Retina/metabolismo , Animais , Apoptose/genética , Astrócitos/patologia , Movimento Celular/genética , Proliferação de Células/genética , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica/genética , Humanos , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Neovascularização Fisiológica/genética , Neurônios/metabolismo , Osteonectina/genética , Osteopontina/genética , Retina/patologia , Trombospondinas/genética , Fator A de Crescimento do Endotélio Vascular/genética
12.
PLoS One ; 15(5): e0232785, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469871

RESUMO

BACKGROUND: Alzheimer's disease (AD) pathology precedes symptoms and its detection can identify at-risk individuals who may benefit from early treatment. Since the retinal nerve fiber layer (RNFL) is depleted in established AD, we tested whether its thickness can predict whether cognitively healthy (CH) individuals have a normal or pathological cerebrospinal fluid (CSF) Aß42 (A) and tau (T) ratio. METHODS: As part of an ongoing longitudinal study, we enrolled CH individuals, excluding those with cognitive impairment and significant ocular pathology. We classified the CH group into two sub-groups, normal (CH-NAT, n = 16) or pathological (CH-PAT, n = 27), using a logistic regression model from the CSF AT ratio that identified >85% of patients with a clinically probable AD diagnosis. Spectral-domain optical coherence tomography (OCT) was acquired for RNFL, ganglion cell-inner plexiform layer (GC-IPL), and macular thickness. Group differences were tested using mixed model repeated measures and a classification model derived using multiple logistic regression. RESULTS: Mean age (± standard deviation) in the CH-PAT group (n = 27; 75.2 ± 8.4 years) was similar (p = 0.50) to the CH-NAT group (n = 16; 74.1 ± 7.9 years). Mean RNFL (standard error) was thinner in the CH-PAT group by 9.8 (2.7) µm; p < 0.001. RNFL thickness classified CH-NAT vs. CH-PAT with 87% sensitivity and 56.3% specificity. CONCLUSIONS: Our retinal data predict which individuals have CSF biomarkers of AD pathology before cognitive deficits are detectable with 87% sensitivity. Such results from easy-to-acquire, objective and non-invasive measurements of the RNFL merit further study of OCT technology to monitor or screen for early AD pathology.


Assuntos
Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Disfunção Cognitiva/genética , Proteínas tau/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Amiloidose/líquido cefalorraquidiano , Amiloidose/diagnóstico por imagem , Amiloidose/genética , Amiloidose/patologia , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/metabolismo , Fibras Nervosas/patologia , Disco Óptico/diagnóstico por imagem , Disco Óptico/metabolismo , Disco Óptico/patologia , Retina/diagnóstico por imagem , Retina/metabolismo , Retina/patologia , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/patologia , Tomografia de Coerência Óptica , Proteínas tau/líquido cefalorraquidiano
13.
Nat Commun ; 11(1): 2338, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393754

RESUMO

Single-cell RNA sequencing (scRNA-seq) can characterize cell types and states through unsupervised clustering, but the ever increasing number of cells and batch effect impose computational challenges. We present DESC, an unsupervised deep embedding algorithm that clusters scRNA-seq data by iteratively optimizing a clustering objective function. Through iterative self-learning, DESC gradually removes batch effects, as long as technical differences across batches are smaller than true biological variations. As a soft clustering algorithm, cluster assignment probabilities from DESC are biologically interpretable and can reveal both discrete and pseudotemporal structure of cells. Comprehensive evaluations show that DESC offers a proper balance of clustering accuracy and stability, has a small footprint on memory, does not explicitly require batch information for batch effect removal, and can utilize GPU when available. As the scale of single-cell studies continues to grow, we believe DESC will offer a valuable tool for biomedical researchers to disentangle complex cellular heterogeneity.


Assuntos
Análise por Conglomerados , Aprendizado Profundo , RNA-Seq , Análise de Célula Única , Algoritmos , Animais , Medula Óssea/metabolismo , Regulação da Expressão Gênica , Humanos , Ilhotas Pancreáticas/metabolismo , Leucócitos Mononucleares/metabolismo , Macaca , Camundongos , Monócitos/metabolismo , Retina/metabolismo
14.
Invest Ophthalmol Vis Sci ; 61(5): 3, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392312

RESUMO

Purpose: The avian eye is an established model for exploring mechanisms that coordinate morphogenesis and metabolism during embryonic development. Less is known, however, about trafficking of bioenergetic and metabolic signaling molecules that are involved in retinal neurogenesis. Methods: Here we tested whether the known 3-day delayed neurogenesis occurring in the pigeon compared with the chick was associated with a deferred reshaping of eye metabolism in vivo. Developmental metabolic remodeling was explored using 1H-magnetic resonance spectroscopy of the whole eye and vitreous body, in ovo, in parallel with biochemical and molecular analyses of retinal, vitreous, and lens extracts from bird embryos. Results: Cross-species comparisons enabled us to show that a major glycolytic switch in the retina is related to neurogenesis rather than to eye growth. We further show that the temporal emergence of an interlocking regulatory cascade controlling retinal oxidative phosphorylation and glycolysis results in the exchange of lactate and citrate between the retina and vitreous. Conclusions: Our results point to the vitreous as a reservoir and buffer of energy metabolites that provides trophic support to oxidative neurons, such as retinal ganglion cells, in early development. Through its control of key glycolytic regulatory enzymes, citrate, exchanged between extracellular and intracellular compartments between the retina and vitreous, is a key metabolite in the initiation of a glycolytic switch.


Assuntos
Olho/embriologia , Glicólise , Ácido Láctico/metabolismo , Neurogênese , Animais , Aves , Ácido Cítrico/metabolismo , Espectroscopia de Ressonância Magnética , Mitocôndrias/metabolismo , Modelos Animais , Fosforilação Oxidativa , Oxigênio/metabolismo , Retina/embriologia , Retina/metabolismo , Corpo Vítreo/embriologia , Corpo Vítreo/metabolismo
15.
Invest Ophthalmol Vis Sci ; 61(5): 13, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32396635

RESUMO

Purpose: Stimulated by evidence implicating diurnal/circadian rhythms and light in refractive development, we studied the expression over 24 hours of selected clock and circadian rhythm-related genes in retina/retinal pigment epithelium (RPE) and choroid of experimental ametropias in chicks. Methods: Newly hatched chicks, entrained to a 12-hour light/dark cycle for 12 to 14 days, either experienced nonrestricted vision OU (i.e., in both eyes) or received an image-blurring diffuser or a minus 10-diopter (D) or a plus 10-D defocusing lens over one eye. Starting 1 day later and at 4-hour intervals for 24 hours, the retina/RPE and choroid were separately dissected. Without pooling, total RNA was extracted, converted to cDNA, and assayed by quantitative PCR for the expression of the following genes: Opn4m, Clock, Npas2, Per3, Cry1, Arntl, and Mtnr1a. Results: The expression of each gene in retina/RPE and in choroid of eyes with nonrestricted vision OU varied over 24 hours, with equal levels OU for most genes and times. Altered visual input influenced gene expression in complex patterns that varied by gene, visual input, time, and eye, affecting experimental eyes with altered vision and also contralateral eyes with nonrestricted vision. Discussion: Altering visual input in ways known to induce ametropias alters the retinal/RPE and choroidal expression of circadian rhythm-related genes, further linking circadian biology with eye growth regulation. While further investigations are needed, studying circadian processes may help understand refractive mechanisms and the increasing myopia prevalence in contemporary societies where lighting patterns can desynchronize endogenous rhythms from the natural environmental light/dark cycle.


Assuntos
Corioide/metabolismo , Ritmo Circadiano/genética , Perfilação da Expressão Gênica , Erros de Refração/etiologia , Retina/metabolismo , Acuidade Visual , Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas CLOCK/genética , Proteínas CLOCK/metabolismo , Galinhas , Criptocromos/genética , Criptocromos/metabolismo , DNA Complementar/metabolismo , Escuridão , Modelos Animais de Doenças , Luz , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Receptor MT1 de Melatonina/genética , Receptor MT1 de Melatonina/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Opsinas de Bastonetes/genética , Opsinas de Bastonetes/metabolismo
16.
Am J Hum Genet ; 106(6): 893-904, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32386558

RESUMO

Kinesin-2 enables ciliary assembly and maintenance as an anterograde intraflagellar transport (IFT) motor. Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. Using exome sequencing, we identified heterozygous KIF3B variants in two unrelated families with hallmark ciliopathy phenotypes. In the first family, the proband presents with hepatic fibrosis, retinitis pigmentosa, and postaxial polydactyly; he harbors a de novo c.748G>C (p.Glu250Gln) variant affecting the kinesin motor domain encoded by KIF3B. The second family is a six-generation pedigree affected predominantly by retinitis pigmentosa. Affected individuals carry a heterozygous c.1568T>C (p.Leu523Pro) KIF3B variant segregating in an autosomal-dominant pattern. We observed a significant increase in primary cilia length in vitro in the context of either of the two mutations while variant KIF3B proteins retained stability indistinguishable from wild type. Furthermore, we tested the effects of KIF3B mutant mRNA expression in the developing zebrafish retina. In the presence of either missense variant, rhodopsin was sequestered to the photoreceptor rod inner segment layer with a concomitant increase in photoreceptor cilia length. Notably, impaired rhodopsin trafficking is also characteristic of recessive KIF3B models as exemplified by an early-onset, autosomal-recessive, progressive retinal degeneration in Bengal cats; we identified a c.1000G>A (p.Ala334Thr) KIF3B variant by genome-wide association study and whole-genome sequencing. Together, our genetic, cell-based, and in vivo modeling data delineate an autosomal-dominant syndromic retinal ciliopathy in humans and suggest that multiple KIF3B pathomechanisms can impair kinesin-driven ciliary transport in the photoreceptor.


Assuntos
Ciliopatias/genética , Ciliopatias/patologia , Genes Dominantes/genética , Cinesina/genética , Mutação , Retina/patologia , Sequência de Aminoácidos , Animais , Gatos , Pré-Escolar , Cílios/patologia , Feminino , Estudo de Associação Genômica Ampla , Heterozigoto , Humanos , Cinesina/química , Cinesina/metabolismo , Larva , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Células Fotorreceptoras/metabolismo , Retina/citologia , Retina/crescimento & desenvolvimento , Retina/metabolismo , Rodopsina/metabolismo , Adulto Jovem , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento
17.
Am J Hum Genet ; 106(6): 859-871, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32470375

RESUMO

Congenital cone-rod synaptic disorder (CRSD), also known as incomplete congenital stationary night blindness (iCSNB), is a non-progressive inherited retinal disease (IRD) characterized by night blindness, photophobia, and nystagmus, and distinctive electroretinographic features. Here, we report bi-allelic RIMS2 variants in seven CRSD-affected individuals from four unrelated families. Apart from CRSD, neurodevelopmental disease was observed in all affected individuals, and abnormal glucose homeostasis was observed in the eldest affected individual. RIMS2 regulates synaptic membrane exocytosis. Data mining of human adult bulk and single-cell retinal transcriptional datasets revealed predominant expression in rod photoreceptors, and immunostaining demonstrated RIMS2 localization in the human retinal outer plexiform layer, Purkinje cells, and pancreatic islets. Additionally, nonsense variants were shown to result in truncated RIMS2 and decreased insulin secretion in mammalian cells. The identification of a syndromic stationary congenital IRD has a major impact on the differential diagnosis of syndromic congenital IRD, which has previously been exclusively linked with degenerative IRD.


Assuntos
Oftalmopatias Hereditárias/genética , Proteínas de Ligação ao GTP/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Mutação com Perda de Função , Miopia/genética , Proteínas do Tecido Nervoso/genética , Cegueira Noturna/genética , Adulto , Alelos , Processamento Alternativo , Encéfalo/metabolismo , Linhagem Celular , Criança , Pré-Escolar , Diagnóstico Diferencial , Saúde da Família , Feminino , França , Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/metabolismo , Glucose/metabolismo , Humanos , Secreção de Insulina , Masculino , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Pâncreas/metabolismo , Linhagem , Retina/metabolismo , Arábia Saudita , Senegal
18.
Adv Exp Med Biol ; 1233: 303-310, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32274763

RESUMO

Primary cilia are microtubule-based sensory organelles that are involved in the organization of numerous key signals during development and in differentiated tissue homeostasis. In fact, the formation and resorption of cilia highly depends on the cell cycle phase in replicative cells, and the ubiquitin proteasome pathway (UPS) proteins, such as E3 ligases and deubiquitinating enzymes, promote microtubule assembly and disassembly by regulating the degradation/availability of ciliary regulatory proteins. Also, many differentiated tissues display cilia, and mutations in genes encoding ciliary proteins are associated with several human pathologies, named ciliopathies, which are multi-organ rare diseases. The retina is one of the organs most affected by ciliary gene mutations because photoreceptors are ciliated cells. Photoreception and phototransduction occur in the outer segment, a highly specialized neurosensory cilium. In this review, we focus on the function of UPS proteins in ciliogenesis and cilia length control in replicative cells and compare it with the scanty data on the identified UPS genes that cause syndromic and non-syndromic inherited retinal disorders. Clearly, further work using animal models and gene-edited mutants of ciliary genes in cells and organoids will widen the landscape of UPS involvement in ciliogenesis and cilia homeostasis.


Assuntos
Cílios/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Retina/citologia , Retina/metabolismo , Ubiquitina/metabolismo , Animais , Humanos , Células Fotorreceptoras/citologia , Células Fotorreceptoras/metabolismo
19.
Invest Ophthalmol Vis Sci ; 61(4): 15, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32298438

RESUMO

Purpose: Pathological neovascularization and fibrosis are common pathological changes of many retinal diseases, such as proliferative retinopathy (PR) and age-related macular degeneration (AMD). Treatment modalities for these pathological changes are limited. The purpose of the present study was to test the effects of palmitoylethanolamide (PEA), an endocannabinoid mimetic amide, on retinal neovascularization and fibrosis and to determine its molecular mechanism of action. Methods: A rat Müller cell line (rMC-1), a mouse model of oxygen-induced retinopathy (OIR), and the very-low-density lipoprotein receptor (VLDLR) knockout mouse model were used. PEA was intraperitoneally injected or orally administrated in animal models. Inflammation and profibrotic changes were evaluated by western blot analysis. Glial fibrillary acidic protein (GFAP) and peroxisome proliferator-activated receptor alpha (PPARα) were measured by RT-PCR and western blot analysis. Results: Profibrotic changes were present in OIR and Vldlr-/- retinas. PEA significantly alleviated inflammation and inhibited neovascularization in OIR and Vldlr-/- retinas and suppressed profibrotic changes in OIR and Vldlr-/- retinas. Moreover, PEA potently suppressed Müller gliosis in these retinas. In rMC-1 cells, PEA suppressed Müller gliosis, reduced inflammatory cytokines, and attenuated profibrotic changes. Further, both mRNA and protein levels of PPARα were elevated in the retina under PEA treatment, and the effects of PEA were abolished in Pparα-/- OIR mice. Conclusions: PEA reduced retinal neovascularization and fibrotic changes and suppressed Müller gliosis in experimental PR and neovascular AMD by activating PPARα. PEA may be a potential treatment for retinopathies with pathological neovascularization and fibrosis.


Assuntos
Agonistas de Receptores de Canabinoides/uso terapêutico , Etanolaminas/uso terapêutico , Gliose/tratamento farmacológico , PPAR alfa/metabolismo , Ácidos Palmíticos/uso terapêutico , Retina/patologia , Neovascularização Retiniana/tratamento farmacológico , Administração Oral , Animais , Western Blotting , Linhagem Celular , Modelos Animais de Doenças , Células Ependimogliais/efeitos dos fármacos , Fibrose/tratamento farmacológico , Fibrose/metabolismo , Fibrose/patologia , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/metabolismo , Gliose/patologia , Marcação In Situ das Extremidades Cortadas , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxigênio/toxicidade , PPAR alfa/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Receptores de LDL/genética , Retina/metabolismo , Neovascularização Retiniana/induzido quimicamente , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia
20.
Proc Natl Acad Sci U S A ; 117(16): 8948-8957, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32241889

RESUMO

Stomatopod crustaceans possess some of the most complex animal visual systems, including at least 16 spectrally distinct types of photoreceptive units (e.g., assemblages of photoreceptor cells). Here we fully characterize the set of opsin genes expressed in retinal tissues and determine expression patterns of each in the stomatopod Neogonodactylus oerstedii Using a combination of transcriptome and RACE sequencing, we identified 33 opsin transcripts expressed in each N. oerstedii eye, which are predicted to form 20 long-wavelength-sensitive, 10 middle-wavelength-sensitive, and three UV-sensitive visual pigments. Observed expression patterns of these 33 transcripts were highly unusual in five respects: 1) All long-wavelength and short/middle-wavelength photoreceptive units expressed multiple opsins, while UV photoreceptor cells expressed single opsins; 2) most of the long-wavelength photoreceptive units expressed at least one middle-wavelength-sensitive opsin transcript; 3) the photoreceptors involved in spatial, motion, and polarization vision expressed more transcripts than those involved in color vision; 4) there is a unique opsin transcript that is expressed in all eight of the photoreceptive units devoted to color vision; and 5) expression patterns in the peripheral hemispheres of the eyes suggest visual specializations not previously recognized in stomatopods. Elucidating the expression patterns of all opsin transcripts expressed in the N. oerstedii retina reveals the potential for previously undocumented functional diversity in the already complex stomatopod eye and is a first step toward understanding the functional significance of the unusual abundance of opsins found in many arthropod species' visual systems.


Assuntos
Crustáceos/fisiologia , Células Fotorreceptoras de Invertebrados/metabolismo , Opsinas de Bastonetes/genética , Animais , Visão de Cores/genética , Duplicação Gênica/fisiologia , Perfilação da Expressão Gênica , Filogenia , Retina/citologia , Retina/metabolismo , Opsinas de Bastonetes/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA