22 research outputs found

    FUS pathology in ALS is linked to alterations in multiple ALS-associated proteins and rescued by drugs stimulating autophagy

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    Amyotrophic lateral sclerosis (ALS) is a lethal disease characterized by motor neuron degeneration and associated with aggregation of nuclear RNA-binding proteins (RBPs), including FUS. How FUS aggregation and neurodegeneration are prevented in healthy motor neurons remain critically unanswered questions. Here, we use a combination of ALS patient autopsy tissue and induced pluripotent stem cell-derived neurons to study the effects of FUS mutations on RBP homeostasis. We show that FUS' tendency to aggregate is normally buffered by interacting RBPs, but this buffering is lost when FUS mislocalizes to the cytoplasm due to ALS mutations. The presence of aggregation-prone FUS in the cytoplasm causes imbalances in RBP homeostasis that exacerbate neurodegeneration. However, enhancing autophagy using small molecules reduces cytoplasmic FUS, restores RBP homeostasis and rescues motor function in vivo. We conclude that disruption of RBP homeostasis plays a critical role in FUS-ALS and can be treated by stimulating autophagy

    Molecular diagnosis and genetic counseling for fragile X mental retardation

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    The fragile X syndrome is the most frequent cause of inherited mental retardation. It is caused by a dynamic mutation: the progressive expansion of polymorphic (CGG)n trinucleotide repeats located in the promoter region of the FMRI gene at Xq27.3. The cloning of the FMRI gene and the elucidation of the molecular basis of the fragile X syndrome is of great importance for the diagnosis and understanding of this unusual type of mutation. Although extensively studied, the mechanism behind the transition from stable normal (CGG)n alleles to the carrier state (an unstable premutation) and from premutation to mutation is partially understood. The clinical diagnosis of fragile X mental retardation (FXMR) is not possible as dysmorphic features are subtle. Molecular diagnosis by Southern Blot is the confirmatory test that makes carrier detection and prenatal diagnosis possible. As the risk of recurrence of FXMR is high in the family and carrier relatives, an identification of fragile X positive children, and offering carrier detection and prenatal diagnosis to the families is very important. It is possible by screening mentally retarded children and adults even if there is no family history of mental retardation or typical behavioral or physical features associated with the fragile X phenotype. In this review we have discussed the method for the diagnosis and counseling of the families. The complexities due to premutation and the variable severity of manifestations in carrier females need to be understood while counseling fragile X families

    C9orf72 poly(PR) mediated neurodegeneration is associated with nucleolar stress

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    Summary: The ALS/FTD-linked intronic hexanucleotide repeat expansion in the C9orf72 gene is aberrantly translated in the sense and antisense directions into dipeptide repeat proteins, among which poly proline-arginine (PR) displays the most aggressive neurotoxicity in-vitro and in-vivo. PR partitions to the nucleus when heterologously expressed in neurons and other cell types. We show that by lessening the nuclear accumulation of PR, we can drastically reduce its neurotoxicity. PR strongly accumulates in the nucleolus, a nuclear structure critical in regulating the cell stress response. We determined that, in neurons, PR caused nucleolar stress and increased levels of the transcription factor p53. Downregulating p53 levels also prevented PR-mediated neurotoxicity both in in-vitro and in-vivo models. We investigated if PR could induce the senescence phenotype in neurons. However, we did not observe any indications of such an effect. Instead, we found evidence for the induction of programmed cell death via caspase-3 activation

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    Not AvailableThe role of microRNA in gene regulation during developmental biology has been well depicted in several organisms. The present study was performed to investigate miRNAs role in the liver tissues during carbohydrate metabolism and their targets in the farmed carp rohu, Labeo rohita, which is economically important species in aquaculture. Using Illumina-HiSeq technology, a total of 22,612,316; 44,316,046 and 13,338,434 clean reads were obtained from three small-RNA libraries. We have identified 138 conserved and 161 novel miRNAs and studies revealed that miR-22, miR-122, miR-365, miR-200, and miR-146 are involved in carbohydrate metabolism. Further analysis depicted mature miRNA and their predicted target sites in genes that were involved in developmental biology, cellular activities, transportation, etc. This is the first report of the presence of miRNAs in liver tissue of rohu and their comparative profile linked with metabolism serves as a vital resource as a biomarker.Not Availabl
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