RESUMO
Retinal ganglion cell (RGC) loss after optic nerve damage is a hallmark of certain human ophthalmic diseases including ischemic optic neuropathy (ION) and glaucoma. In a rat model of optic nerve transection, in which 80% of RGCs are eliminated within 14 days, caspase-2 was found to be expressed and cleaved (activated) predominantly in RGC. Inhibition of caspase-2 expression by a chemically modified synthetic short interfering ribonucleic acid (siRNA) delivered by intravitreal administration significantly enhanced RGC survival over a period of at least 30 days. This exogenously delivered siRNA could be found in RGC and other types of retinal cells, persisted inside the retina for at least 1 month and mediated sequence-specific RNA interference without inducing an interferon response. Our results indicate that RGC apoptosis induced by optic nerve injury involves activation of caspase-2, and that synthetic siRNAs designed to inhibit expression of caspase-2 represent potential neuroprotective agents for intervention in human diseases involving RGC loss.
Assuntos
Caspase 2/deficiência , Citoproteção/genética , Glaucoma/prevenção & controle , Fármacos Neuroprotetores , Nervo Óptico/metabolismo , Nervo Óptico/patologia , RNA Interferente Pequeno/genética , Animais , Apoptose/genética , Caspase 2/biossíntese , Caspase 2/genética , Caspase 2/metabolismo , Modelos Animais de Doenças , Feminino , Glaucoma/enzimologia , Glaucoma/genética , Glaucoma/patologia , Nervo Óptico/enzimologia , Ratos , Ratos Wistar , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/metabolismo , Relação Estrutura-AtividadeAssuntos
Colesterol/deficiência , Colesterol/fisiologia , Desmosterol/metabolismo , Proteínas do Tecido Nervoso/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Tecido Adiposo , Animais , Ácidos e Sais Biliares/biossíntese , Colesterol/sangue , Colesterol/metabolismo , Feminino , Marcação de Genes , Crescimento , Humanos , Infertilidade , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Proteínas do Tecido Nervoso/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Fenótipo , Caracteres Sexuais , Testículo/patologiaRESUMO
Neural crest (NC) cells migrate exclusively into the rostral half of each sclerotome, where they avoid the dermomyotome and the paranotochordal sclerotome. F-spondin is expressed in these inhibitory regions and throughout the caudal halves. In vitro bioassays of NC spreading on substrates of rostral or caudal epithelial-half somites (RS or CS, respectively) revealed that NC cells adopt on RS a fibroblastic morphology, whereas on CS they fail to flatten. F-spondin inhibited flattening of NC cells on RS. Conversely, F-spondin antibodies prevented rounding up of NC cells on CS. Addition of F-spondin to trunk explants inhibited NC migration into the sclerotome, and treatment of embryos with anti-F-spondin antibodies yielded migration into otherwise inhibitory sites. Thus, somite-derived F-spondin is an inhibitory signal involved in patterning the segmental migration of NC cells and their topographical segregation within the RS.
Assuntos
Movimento Celular/fisiologia , Substâncias de Crescimento , Moléculas de Adesão de Célula Nervosa/fisiologia , Crista Neural/citologia , Neurônios/fisiologia , Peptídeos , Somitos/metabolismo , Animais , Células Cultivadas , Embrião de Galinha , Técnicas de Cocultura , Imuno-Histoquímica , Hibridização In Situ , Microinjeções , Microscopia Confocal , Moléculas de Adesão de Célula Nervosa/biossíntese , Moléculas de Adesão de Célula Nervosa/genética , Crista Neural/embriologia , Neurônios/ultraestrutura , RNA Mensageiro/biossíntese , Transdução de Sinais/fisiologiaRESUMO
Winnicott described in his book 'Therapeutic Consultations' (1971) how a diagnostic assessment of a referred child developed into a fruitful therapeutic intervention when he was able to discover the unconscious fantasy that underlay the child's symptoms. Because these were children who were, essentially, developing normally, he used the word 'knot' to depict the obstacle the child had met. Any conflicts the parents might have were not explored in that context. This work present cases in which child and parents are seen together for the diagnostic assessment. The child's feelings about his world and his difficulties are explored through a variety of techniques including drawings. In the same interview, an analytic enquiry into the parents' history and also their views of the child reveals how the child's fantasies and the parents' past experiences interact and create a mutually reinforcing vicious circle. In other words, the 'knot' involves all of them. If the child's unconscious fantasy can be verbalised and if the parents are able to approach the child in a manner that acknowledges the child's real needs, the 'knot' disappears and normal development can be resumed.
