Myotonic dystrophes (DM), the most common adult muscular dystrophy, are the first recognized examples of RNA-mediated diseases in which expression of mutant RNAs containing expanded CUG or CCUG repeats interfere with the splicing of other mRNAs. Using whole-genome microarrays, we found that alternative splicing of the BIN1 mRNA is altered in DM skeletal muscle tissues, resulting in the expression of an inactive form of BIN1 deprived of phosphoinositide-binding and membrane-tubulating activities. BIN1 is involved in tubular invaginations of the plasma membrane and is essential for biogenesis of the muscle T-tubules, which are specialized skeletal muscle membrane structures essential to correct excitation-contraction (E-C) coupling. Mutations in the BIN1 gene cause centronuclear myopathy (CNM) that shares some histopathological features with DM, and both diseases are characterized by muscle weakness. Consistent with a loss-of-function of BIN1, muscle T-tubules were altered in DM patients, and membrane tubulation was restored upon expression of the correct splicing form of BIN1 in DM muscle cells. By deciphering the mechanism of BIN1 splicing mis-regulation we demonstrate that the splicing regulator, MBNL1, which is sequestered by expanded CUG and CCUG in DM, binds the BIN1 pre-mRNA and regulates directly its alternative splicing. Finally, reproducing BIN1 splicing alteration in mice is sufficient to reproduce the DM features of T-tubule alterations and muscle weakness. We propose that alteration of BIN1 alternative splicing regulation leads to muscle weakness, a predominant pathological feature of DM.
Misregulated alternative splicing of BIN1 is associated with T tubule alterations and muscle weakness in myotonic dystrophy.
Specimen part
View SamplesAnalysis of alternative splicing in heart (left ventricles) samples of 3 adult DM1 patients versus 3 adult controls Overall design: PolyA RNA from left ventricles (heart) of 3 controls and 3 DM1 patients were analysed by massive parrallel sequencing
Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy.
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View SamplesAnalysis of alternative splicing of left ventricles heart samples of 3 DM1 adult versus 3 adult controls
Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy.
Specimen part, Disease, Disease stage
View SamplesRibosome profiling of MDA-MB-231 cells treated with Silvestrol to monitor transcriptome wide, eIF4A-dependent changes in translation efficiency Overall design: Translation efficiency (TE) of mRNAs dervied from ribosome footprints was monitored in the presence or absence of 25 nM Silvestrol, an inhibitor of eukaryotic translation initiation factor 4A (eIF4A). Transcripts with reduced TE in the presence of Silvestrol were compare to transcripts with reduced TE in the presence of INK128, a catalytic mTOR inhbitor.
Transcriptome-wide characterization of the eIF4A signature highlights plasticity in translation regulation.
No sample metadata fields
View SamplesPersons with Down syndrome (DS) exhibit low muscle strength that significantly impairs their physical functioning. The Ts65Dn mouse model of DS also exhibits muscle weakness in vivo and may serve as a useful model to examine potential factors responsible for DS-associated muscle dysfunction. Therefore, the purpose of this experiment was to directly assess skeletal muscle function in the Ts65Dn mouse and to reveal potential mechanisms of DS-associated muscle weakness. Soleus muscles were harvested from anesthetized male Ts65Dn and wild-type (WT) colony controls. In vitro muscle contractile experiments revealed normal force generation of unfatigued Ts65Dn soleus, but a 12% reduction in force was observed in Ts65Dn muscle during recovery following fatiguing contractions compared to WT muscle (p<0.05). Oxidative stress may contribute to DS-related pathologies, including muscle weakness, which may be the result of overexpression of chromosome 21 genes (e.g., copper-zinc superoxide dismutase (SOD1)). SOD1 expression was 25% higher (p<0.05) in Ts65Dn soleus compared to WT muscle but levels of other antioxidant proteins were unchanged. Lipid peroxidation (4-hydroxynoneal) was unaltered in Ts65Dn muscle although protein carbonyls were 20% greater compared to muscle of WT animals (p<0.05). Cytochrome c oxidase expression was reduced 22% in Ts65Dn muscle, suggesting a limitation in mitochondrial function may contribute to post-fatigue muscle weakness. Microarray analysis of Ts65Dn soleus revealed alteration of numerous cellular pathways including: proteolysis, glucose and fat metabolism, neuromuscular transmission, and ATP biosynthesis. In summary, the Ts65Dn mouse displays evidence of muscle dysfunction, and the potential role of mitochondria and oxidative stress warrants further investigation.
Functional and biochemical characterization of soleus muscle in Down syndrome mice: insight into the muscle dysfunction seen in the human condition.
Sex, Age, Specimen part
View SamplesBackground: Heat stress triggers an evolutionarily conserved set of responses in cells. The transcriptome responds to hyperthermia by altering expression of genes to adapt the cell or organism to survive the heat challenge. RNA-seq technology allows rapid identification of environmentally responsive genes on a large scale. In this study, we have used RNA -seq to identify heat stress responsive genes in the chicken male white-leghorn hepat ocellular (LMH) cell line. Result: The transcripts of 812 genes were responsive to heat stress (p <0.01) with 235 genes up- regulated and 577 down-regulated following 2.5 hours of heat stress. Among the up- regulated were genes whose products function as chaperones, along with genes aff ecting collagen synthesis and deposition, transcription factors, chromatin remodelers and genes modulating the WNT and TGF-beta pathways. Predominant among the down-regulated genes were ones that affect DNA replication and repair along with chromosom al segregation. Many of the genes identified in this study have not been previously implicated in the heat stress response. Conclusion: These data extend our understanding of the transcriptome response to heat stress. Many of the identified biological processes and pathways likely function in adapting cells and organisms to hyperthermic stress. This study may provide important guides to future efforts attempting to improve species abilities to withstand heat stress through genome wide association studies and breeding. In addition, the genes down regulated by heat stress may provide important targets for improving hyperthemic treatment in cancer patients. Overall design: Cells were grown at either control ( 37oC) or heat stress (43oC) temperatures for 2.5 hours.
Transcriptome response to heat stress in a chicken hepatocellular carcinoma cell line.
Cell line, Treatment, Subject
View SamplesPurpose:This work aimed to identify the genetic profiles of piriform projection neurons and characterize their spatial organization within the piriform cortex. Methods: We microdissected the three layers of pirifrom cortex by laser capture (LMD) and performed RNA deep sequencing in order to identify layer-specific molecular markers, we then validated these data by using RNA in situ hybridization and immunohistochemistry.We next performed anterograde neural tracing experiments to identify piriform target regions, and retrograde neural tracing experiments to analyze how piriform projection neurons are organized within piriform cortex.We then combined the analysis of patterns of gene expression with retrograde tracing experiments to identify molecular signatures of the different subclasses of piriform projecting neurons. Results:We show that layers and sub-layers of the piriform cortex can be discriminated by gene expression patterns in adult piriform cortex. We observe that neurons projecting to distinct target areas are localized in distinct layers and express specific genes. We demonstrate that these molecular signatures of piriform projection neurons are maintained in reeler mice, in which cortical lamination is lost and neural positioning is scrambled, suggesting that piriform output connectivity strictly depends on the molecular programm, rather than a proper lamination of the cortex. Conclusion:These results provide important insights into the principles underling the piriform connectivity. Overall design: 3 replicates per each layer (three layers) of piriform cotrex were used for the RNA deep sequancing
Molecular signatures of neural connectivity in the olfactory cortex.
No sample metadata fields
View SamplesTo adapt the lives of organisms to the day-night cycle, evolution has built a complex machinery, whose molecular components are able to anticipate and drive changes in organism behavior and metabolism. A mutual bidirectional interaction exists between circadian abnormalities and development of diseases.
Circadian clock regulates the host response to Salmonella.
Age, Specimen part
View SamplesRationale: Lipopolysaccharide (LPS) is ubiquitous in the environment. Inhalation of LPS has been implicated in the pathogenesis and/or severity of several lung diseases, including pneumonia, chronic obstructive pulmonary disease and asthma. Alveolar macrophages are the main resident leukocytes exposed to inhaled antigens. Objectives: To obtain insight into which innate immune pathways become activated within human alveolar macrophages upon exposure to LPS in vivo.
Gene expression profiles in alveolar macrophages induced by lipopolysaccharide in humans.
Sex, Specimen part, Treatment, Subject
View SamplesData defines for the first time a whole bladder transcriptome of UPEC cystitis in female C57BL/6 mice using genome-wide expression profiling to map early host response pathways stemming from UPEC colonization
Innate transcriptional networks activated in bladder in response to uropathogenic Escherichia coli drive diverse biological pathways and rapid synthesis of IL-10 for defense against bacterial urinary tract infection.
Sex, Age, Specimen part
View Samples