RESUMEN
Once-daily (p.m.) netarsudil ophthalmic solution 0.02% (Rhopressa) is approved in the United States for lowering elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. Netarsudil, a Rho kinase (ROCK) inhibitor that lowers IOP primarily by increasing trabecular outflow, produces statistically and clinically significant reductions in mean IOP from baseline, with comparable effects on nocturnal and diurnal IOP. In three phase III trials of patients with elevated IOP, the ocular hypotensive efficacy of once-daily netarsudil 0.02% met the criteria for noninferiority to twice-daily timolol 0.5% at all time points over 3 months in patients with baseline IOP less than 25 mmHg. The most frequent adverse event (AE) was generally mild conjunctival hyperemia, the severity of which did not increase with continued dosing. Netarsudil was associated with minimal treatment-related serious or systemic AEs, likely due to the lack of systemic exposure. This report summarizes the available preclinical and clinical data on netarsudil.
Asunto(s)
Benzoatos/administración & dosificación , Ojo/efectos de los fármacos , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Presión Intraocular/efectos de los fármacos , Hipertensión Ocular/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , beta-Alanina/análogos & derivados , Administración Oftálmica , Animales , Benzoatos/efectos adversos , Benzoatos/farmacocinética , Interacciones Farmacológicas , Ojo/enzimología , Ojo/fisiopatología , Glaucoma de Ángulo Abierto/diagnóstico , Glaucoma de Ángulo Abierto/enzimología , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Hipertensión Ocular/diagnóstico , Hipertensión Ocular/enzimología , Hipertensión Ocular/fisiopatología , Soluciones Oftálmicas , Inhibidores de Proteínas Quinasas/efectos adversos , Inhibidores de Proteínas Quinasas/farmacocinética , Resultado del Tratamiento , beta-Alanina/administración & dosificación , beta-Alanina/efectos adversos , beta-Alanina/farmacocinética , Quinasas Asociadas a rho/antagonistas & inhibidores , Quinasas Asociadas a rho/metabolismoRESUMEN
The midline glia are specialized, nonneuronal cells at the midline of the Drosophila central nervous system (CNS). During development, the midline glia provide guidance cues for extending axons. At the same time, they migrate and help separate the two axon commissures. They then wrap around and ensheath the commissural axons. In many segments, a few of the glia do not enwrap the axons, and these cells die. The wrapper gene encodes a novel member of the immunoglobulin (Ig) superfamily. Wrapper protein is expressed specifically on the surface of midline glia. In wrapper mutant embryos, the midline glia express their normal guidance cues and migrate normally. However, they do not ensheath the commissural axons, and as a result, the glia die. In the absence of Wrapper, the two axon commissures are not properly separated.
Asunto(s)
Axones/fisiología , Proteínas de Drosophila , Inmunoglobulinas/química , Proteínas de Insectos/química , Proteínas del Tejido Nervioso/biosíntesis , Neuroglía/metabolismo , Secuencia de Aminoácidos , Animales , Drosophila/embriología , Drosophila/genética , Regulación del Desarrollo de la Expresión Génica , Inmunoglobulinas/genética , Proteínas de Insectos/genética , Datos de Secuencia Molecular , Familia de Multigenes , Mutagénesis , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/fisiología , Homología de Secuencia de AminoácidoRESUMEN
Secreted and transmembrane proteins play an essential role in intercellular communication during the development of multicellular organisms. Because only a small number of these genes have been characterized, we developed a screen for genes encoding extracellular proteins that are differentially expressed during Drosophila embryogenesis. Our approach utilizes a new method for screening large numbers of cDNAs by whole-embryo in situ hybridization. The cDNA library for the screen was prepared from rough endoplasmic reticulum-bound mRNA and is therefore enriched in clones encoding membrane and secreted proteins. To increase the prevalence of rare cDNAs in the library, the library was normalized using a method based on cDNA hybridization to genomic DNA-coated beads. In total, 2,518 individual cDNAs from the normalized library were screened by in situ hybridization, and 917 of these cDNAs represent genes differentially expressed during embryonic development. Sequence analysis of 1,001 cDNAs indicated that 811 represent genes not previously described in Drosophila. Expression pattern photographs and partial DNA sequences have been assembled in a database publicly available at the Berkeley Drosophila Genome Project website (). The identification of a large number of genes encoding proteins involved in cell-cell contact and signaling will advance our knowledge of the mechanisms by which multicellular organisms and their specialized organs develop.
Asunto(s)
Drosophila/embriología , Drosophila/genética , Genes de Insecto , Proteínas de Insectos/genética , Animales , Redes de Comunicación de Computadores , ADN Complementario/genética , Bases de Datos Factuales , Drosophila/fisiología , Regulación del Desarrollo de la Expresión Génica , Hibridación in Situ , Proteínas de Insectos/fisiología , Proteínas de la Membrana/genética , Proteínas de la Membrana/fisiología , Datos de Secuencia Molecular , ARN Mensajero/genética , ARN Mensajero/aislamiento & purificaciónRESUMEN
Upon contacting its postsynaptic target, a neuronal growth cone transforms into a presynaptic terminal. A membrane component on the growth cone that facilitates synapse formation was identified by means of a complementary DNA-based screen followed by genetic analysis. The late bloomer (lbl) gene in Drosophila encodes a member of the tetraspanin family of cell surface proteins. LBL protein is transiently expressed on motor axons, growth cones, and terminal arbors. In lbl mutant embryos, the growth cone of the RP3 motoneuron contacts its target muscles, but synapse formation is delayed and neighboring motoneurons display an increase in ectopic sprouting.
Asunto(s)
Proteínas de Drosophila , Genes de Insecto , Proteínas de la Membrana/fisiología , Neuronas Motoras/fisiología , Proteínas del Tejido Nervioso/fisiología , Unión Neuromuscular/fisiología , Terminales Presinápticos/fisiología , Secuencia de Aminoácidos , Animales , Axones/metabolismo , Axones/ultraestructura , Clonación Molecular , Drosophila/embriología , Drosophila/genética , Drosophila/fisiología , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Neuronas Motoras/citología , Neuronas Motoras/metabolismo , Músculos/inervación , Mutación , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Terminales Presinápticos/ultraestructura , Transducción de SeñalRESUMEN
Introns excised from the primary transcript of Delta (Dl), a Drosophila neurogenic gene, accumulate to unusually high levels in embryos. High resolution in situ hybridization reveals a striking localization of the excised introns to two foci per embryonic nucleus. The number of foci can be altered by varying the number of Dl genes present in the embryonic nucleus, suggesting that the excised introns are localized near sites of Dl transcription. This conclusion is supported by the observation that larval and imaginal disc nuclei containing two copies of Dl exhibit only one focus of intron accumulation, as expected for nuclei in which homologous chromosomes are paired. Interestingly, the excised introns do not appear to diffuse away from the foci until late prophase, at which time the foci disperse into numerous small dots of hybridization. These results suggest that the excised Dl introns may be associated with a structural element within the nucleus that is dissociated during cell division.
Asunto(s)
Núcleo Celular/fisiología , Drosophila melanogaster/genética , Intrones , Transcripción Genética , Animales , Secuencia de Bases , Cromosomas/fisiología , Drosophila melanogaster/embriología , Embrión no Mamífero/fisiología , Exones , Hibridación in Situ , Interfase , Mitosis , Datos de Secuencia Molecular , Sistema Nervioso/embriología , Fenómenos Fisiológicos del Sistema Nervioso , Oligodesoxirribonucleótidos , Reacción en Cadena de la Polimerasa , ARN/genética , ARN/aislamiento & purificaciónAsunto(s)
Drosophila/genética , Ectodermo/fisiología , Hormonas de Insectos/genética , Proteínas de la Membrana/genética , Animales , Diferenciación Celular/genética , Proteínas de Drosophila , Péptidos y Proteínas de Señalización Intracelular , Mutación , Receptores Notch , Homología de Secuencia de Ácido NucleicoRESUMEN
Delta (Dl) function is required for proper specification of epidermal and neural lineages within the neurogenic ectoderm of Drosophila melanogaster. We have determined the spatial accumulation of five Dl transcripts that arise as the result of alternative RNA processing during embryogenesis. We find that these transcripts accumulate in all cells of the neurogenic ectoderm immediately preceding neuroblast segregation, indicating that transcription of Dl does not differ between presumptive neuroblasts and presumptive dermoblasts. Dl transcripts also accumulate transiently in mesodermal and endodermal cells, suggesting that Dl may function in developmental processes in addition to differentiation of the neurogenic ectoderm. We find that three of the Dl transcripts are localized to the base of the nucleus during cellularization. The apparent association of these three transcripts with polysomes suggests that they accumulate within the cytoplasm at the nuclear periphery and is consistent with the hypothesis that Dl encodes multiple translational products.
Asunto(s)
Drosophila/embriología , Genes/genética , Animales , Autorradiografía , Compartimento Celular , Diferenciación Celular/genética , Sistema Nervioso Central/embriología , Centrifugación Zonal , Citoplasma , Drosophila/genética , Ectodermo/fisiología , Epidermis/embriología , Membrana Nuclear , Hibridación de Ácido Nucleico , Polirribosomas , ARN Mensajero/metabolismo , Transcripción Genética/genéticaRESUMEN
Delta (Dl) is one of the six known zygotic neurogenic genes, each of which is essential for proper segregation of the embryonic ectoderm into neural and epidermal lineages. Molecular analysis of Dl reveals that it is a transcriptionally complex locus that yields multiple maternal and zygotic transcripts. DNA sequence analysis suggests that the predominant product of the locus is a putative transmembrane protein exhibiting homology to blood coagulation factors and epidermal growth factor of vertebrates. The structure of this product is consistent with the hypothesis that Dl participates in cell-cell interactions that are central to establishment of the epidermal lineage within the developing ectoderm. Genetic analyses demonstrate that Dl mutations can modify the imaginal phenotypes that result from heterozygosity for Notch (N) mutations as well as the interaction between particular alleles of Notch (N) and Enhancer of split [E(spl)], two other members of the neurogenic gene set. Vital interactions also occur between Dl and N. Given the structures of products encoded by N, Dl, and E(spl), we suggest that the synergistic phenotypic interactions observed among mutations in these three loci result from physical, as opposed to regulatory, interactions.
Asunto(s)
Drosophila melanogaster/genética , Alelos , Animales , ADN/genética , Drosophila melanogaster/crecimiento & desarrollo , Ectodermo/anatomía & histología , Anomalías del Ojo , Femenino , Mutación , Fenotipo , Biosíntesis de Proteínas , Transcripción GenéticaRESUMEN
Delta (D1) is required for normal segregation of the embryonic ectoderm into neural and epidermal cell lineages in Drosophila melanogaster. Loss-of-function mutations in D1 and other zygotic neurogenic loci lead to expansion of the neuroblast population at the expense of the dermoblast population within the ectoderm. Characterization of the transcriptional organization and maternal/embryonic expression within the chromosomal interval corresponding to D1 reveals that the locus encodes multiple transcripts: a minimum of two maternal transcripts, approximately 4.5 and 3.6 kb in length, and four zygotic transcripts, approximately 5.4 (two distinct species), 3.5, and 2.8 kb in length. These transcripts differ on the bases of differential splicing and differential polyadenylation site choice. The DNA sequence of a cDNA clone representing the predominant transcripts of the locus indicates that D1 encodes a transmembrane protein homologous to blood coagulation factors and epidermal growth factor. The relationship between coding sequences and transcript-specific exons within the locus suggests that D1 encodes multiple translational products.
Asunto(s)
Factores de Coagulación Sanguínea/genética , Drosophila melanogaster/genética , Factor de Crecimiento Epidérmico/genética , Genes , Proteínas de la Membrana/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Drosophila melanogaster/embriología , Immunoblotting , Datos de Secuencia Molecular , Neuronas/embriología , Especificidad de la Especie , Transcripción Genética , Vertebrados/genéticaRESUMEN
Poly(A)+ RNA was isolated from maize scutella of different stages of post-germinative development and translated in vitro in a rabbit reticulocyte translation system. Immunoprecipitation of the translation products with CAT-2-specific antibody was used to quantitate the relative levels of translatable CAT-2 mRNA at each stage. The results show a close correlation between the developmental profile of Cat2 gene expression and the profile of CAT-2 mRNA levels. Evidence that the levels of CAT-2 mRNA are regulated by a temporal regulatory gene (Car1) is presented and the possible mechanism(s) of this regulation discussed.