RESUMO
Intellectual Disability (ID) disorders, defined by an IQ below 70, are genetically and phenotypically highly heterogeneous. Identification of common molecular pathways underlying these disorders is crucial for understanding the molecular basis of cognition and for the development of therapeutic intervention strategies. To systematically establish their functional connectivity, we used transgenic RNAi to target 270 ID gene orthologs in the Drosophila eye. Assessment of neuronal function in behavioral and electrophysiological assays and multiparametric morphological analysis identified phenotypes associated with knockdown of 180 ID gene orthologs. Most of these genotype-phenotype associations were novel. For example, we uncovered 16 genes that are required for basal neurotransmission and have not previously been implicated in this process in any system or organism. ID gene orthologs with morphological eye phenotypes, in contrast to genes without phenotypes, are relatively highly expressed in the human nervous system and are enriched for neuronal functions, suggesting that eye phenotyping can distinguish different classes of ID genes. Indeed, grouping genes by Drosophila phenotype uncovered 26 connected functional modules. Novel links between ID genes successfully predicted that MYCN, PIGV and UPF3B regulate synapse development. Drosophila phenotype groups show, in addition to ID, significant phenotypic similarity also in humans, indicating that functional modules are conserved. The combined data indicate that ID disorders, despite their extreme genetic diversity, are caused by disruption of a limited number of highly connected functional modules.
Assuntos
Olho/metabolismo , Deficiência Intelectual/genética , Redes e Vias Metabólicas/genética , Sinapses/genética , Animais , Animais Geneticamente Modificados , Drosophila/genética , Olho/crescimento & desenvolvimento , Técnicas de Silenciamento de Genes , Variação Genética , Humanos , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Neurônios/metabolismo , Fenótipo , Interferência de RNA , Sinapses/metabolismoRESUMO
BACKGROUND: Extracorporeal perfusion (ECP) is a promising technique for prolonged tissue preservation, but might have side effects. For instance, increased radical oxygen species or capillary endothelial damage. OBJECTIVE: To assess ultra-morphological muscle damage during 36-hour ECP of porcine musculocutaneous flaps, hypothesizing that it would delay the onset of damage compared to static cold storage (SCS). METHODS: Bilateral flaps were retrieved from three Dutch Landrace pigs. Three flaps were preserved for 36 hours by hypothermic storage 4-6°C (control group) and three flaps by ECP with cooled University of Wisconsin solution. Muscle biopsies were taken at 0âh, 12âh and 36âh and assessed with transmission electron microscopy. RESULTS: Muscle architecture was best preserved by ECP, with a delayed onset and decreased severity of muscle damage. After 36 hours, damage was two-fold lower in ECP-flaps compared to SCS-flaps. Myofibril architecture was best preserved. Mitochondria were greatly preserved with swelling being the most prominent feature. Capillaries were moderately but differently damaged during ECP, with focal endothelial thinning as opposed to luminal obstruction in SCS-preserved flaps. CONCLUSIONS: This experiment described favourable cellular preservation of skeletal muscle flaps during ECP compared to SCS. Results showed less severe ultra-morphological damage and a later onset of damage.
Assuntos
Soluções para Preservação de Órgãos , Preservação de Órgãos , Suínos , Animais , Preservação de Órgãos/métodos , Miofibrilas , Capilares , Perfusão/métodos , Microscopia Eletrônica de Transmissão , MitocôndriasRESUMO
Nemaline myopathy type 6 (NEM6), KBTBD13-related congenital myopathy is caused by mutated KBTBD13 protein that interacts improperly with thin filaments/actin, provoking impaired muscle-relaxation kinetics. We describe muscle morphology in 18 Dutch NEM6 patients and correlate it with clinical phenotype and pathophysiological mechanisms. Rods were found in in 85% of biopsies by light microscopy, and 89% by electron microscopy. A peculiar ring disposition of rods resulting in ring-rods fiber was observed. Cores were found in 79% of NEM6 biopsies by light microscopy, and 83% by electron microscopy. Electron microscopy also disclosed granulofilamentous protein material in 9 biopsies. Fiber type 1 predominance and prominent nuclear internalization were found. Rods were immunoreactive for α-actinin and myotilin. Areas surrounding the rods showed titin overexpression suggesting derangement of the surrounding sarcomeres. NEM6 myopathology hallmarks are prominent cores, rods including ring-rods fibers, nuclear clumps, and granulofilamentous protein material. This material might represent the histopathologic epiphenomenon of altered interaction between mutated KBTBD13 protein and thin filaments. We claim to classify KBTBD13-related congenital myopathy as rod-core myopathy.