Genes specific to Sox9+ pancreatic progenitors were identified by comparing the gene expression in embryonic and adult Sox9+ cells.
A Notch-dependent molecular circuitry initiates pancreatic endocrine and ductal cell differentiation.
Specimen part
View SamplesSpinal cord injury leads to impaired motor and sensory functions. After spinal cord injury there is a an initial phase of hypo-reflexia followed by a developing hyper-reflexia, often termed spasticity. Previous studies have suggested a relationship between the reappearence of plateau potentials in motor neurons and the development of spasticity after spinalizaion. To understand the moleclar mechanism behind this pheneomona we examined the transcriptional response of the motor neurons after spinal cord injury as it progress over time.
Transcriptional regulation of gene expression clusters in motor neurons following spinal cord injury.
Sex, Specimen part
View SamplesLoss of muscle mass occurs in a variety of diseases including cancer, chronic heart failure, AIDS, diabetes and renal failure, often aggravating pathological progression. Preventing muscle wasting by promoting muscle growth has been proposed as a possible therapeutic approach. Myostatin is an important negative modulator of muscle growth during myogenesis and myostatin inhibitors are attractive drug targets. However, the role of the myostatin pathway in adulthood and the transcription factors involved in the signaling are unclear. Moreover recent results confirm that other TGF members control muscle mass. Using genetic tools we perturbed this pathway in adult myofibers, in vivo, to characterize the downstream targets and their ability to control muscle mass. Smad2 and Smad3 are the transcription factors downstream of myostatin/TGF and induce an atrophy program which is MuRF1 independent and requires FoxO activity. Furthermore Smad2/3 inhibition promotes muscle hypertrophy independent of satellite cells but partially dependent of mTOR signalling. Thus myostatin and Akt pathways cross-talk at different levels. These findings point to myostatin inhibitors as good drugs to promote muscle growth during rehabilitation especially when they are combined with IGF1-Akt activators.
Smad2 and 3 transcription factors control muscle mass in adulthood.
Specimen part, Time
View SamplesThe present study was designed to test the hypothesis that limited growth of the fetal liver in the model of maternal fasting is independent of well-characterized signaling mechanisms that are known to regulate somatic growth in adult animals.
Regulation of fetal liver growth in a model of diet restriction in the pregnant rat.
Specimen part, Treatment
View SamplesSequencing of 5' ends of RNA molecules from control and exosome-depleted HeLa-S3 cells. Overall design: CAGE library construction from RNA extracted from control and exosome-depleted cells.
Nuclear stability and transcriptional directionality separate functionally distinct RNA species.
No sample metadata fields
View SamplesGene expression programs change during cellular transitions. It is well established that a network of transcription factors and chromatin modifiers regulate RNA levels during embryonic stem cell (ESC) differentiation, but the full impact of post-transcriptional processes remains elusive. While cytoplasmic RNA turnover mechanisms have been implicated in differentiation, the contribution of nuclear RNA decay has not been investigated. Here, we differentiate mouse ESCs, depleted for the ribonucleolytic RNA exosome, into embryoid bodies to determine to which degree RNA abundance in the two states can be attributed to changes in transcription vs. RNA decay by the exosome. As a general observation, we find that exosome depletion mainly leads to the stabilization of RNAs from lowly transcribed loci, including several protein-coding genes. In particular, transcripts that are differentially expressed between states tend to be more exosome sensitive in the state where expression is low. We conclude that the RNA exosome contributes to down-regulation of transcripts with disparate expression, often in conjunction with transcriptional down-regulation. Overall design: CAGE experiments were carried out in mouse embryonic stem cells and embryoid bodies differentiated for three days upon depletion of RRP40 with shRNAs, using a scrambled shRNA as control. The experiments were performed in duplicates
The RNA exosome contributes to gene expression regulation during stem cell differentiation.
Specimen part, Cell line, Subject
View SamplesTo investigate genes possibly regulated by TTF-1 in small cell lung cancer cell lines, we compared gene expression profiles of NCI-H209 and Lu139 cell lines electroporated with control and TTF-1 siRNAs.
An integrative transcriptome analysis reveals a functional role for thyroid transcription factor-1 in small cell lung cancer.
Cell line
View SamplesOur strategy was to manipulate mTOR signaling in vivo, then characterize the transcriptome and translating mRNA in liver tissue. In adult rats, we used the non-proliferative growth model of refeeding after a period of fasting, and the proliferative model of liver regeneration following partial hepatectomy. We also studied livers from pre-term fetal rats (embryonic day 19-20) in which fetal hepatocytes are asynchronously proliferating. All three models employed rapamycin to inhibit mTOR signaling.
Profiling of the fetal and adult rat liver transcriptome and translatome reveals discordant regulation by the mechanistic target of rapamycin (mTOR).
Specimen part, Time
View SamplesLiver transplantation is the only therapeutic option for patients with end-stage liver disease. The shortage of donor organs has led to the search for alternative therapies to restore liver function and bridge patients to transplantation. Our previous work has shown that the proliferation of late gestation E19 fetal hepatocytes is mitogen-independent. This is manifested as differences in the control of ribosome biogenesis, global translation, cell cycle progression and gene expression. In the present study, we investigated whether E19 fetal hepatocytes would engraft and repopulate an injured adult liver.
Engraftment and Repopulation Potential of Late Gestation Fetal Rat Hepatocytes.
Specimen part
View SamplesInjury to anterior cruciate ligament (ACL) is common in young individuals and a frequent cause of functional instability and early onset of osteoarthritis. The healing potential of an injured ACL is known to decay over time. The molecular origin of this healing deficiency largely remains elusive but plausibly involves gene transcripts associated with tissue healing. To explore this possibility, we set out to identify transcript expression differences in injured ACL remnants recovered at the time of surgical reconstruction, via microarray (n=24) and RNA-seq (n=8) technologies in transcriptome profiling. We found that time-from-injury was an important determinant of changes in gene expression signatures predominately resulting in repression of several biological processes as identified by gene ontology. The most interesting observation was a time-dependent decline in the gene transcripts as well as the biological processes common to both microarray and RNA-seq analyses. Compared to acute tears, in chronic several important biological processes were namely extracellular matrix organization, angiogenesis, cell adhesion, wound healing, mesenchyme transition, and response to hypoxia. Furthermore, the cross-platform concordance in terms of differentially expressed transcripts or enriched pathways was linearly correlated (r=0.64). Microfluidic digital PCR confirmed the expression of selected differentially expressed transcripts. These intriguing findings suggest an initial attempt of the injured ACL to repair, which drops with time. These findings have implications for efforts to repair the ACL and may be relevant for its reconstruction. These findings also emphasize the utility of differentially expressed transcripts as prognostic biomarkers in patients with ACL injury. Overall design: Examination of transcript expression differences by time-from-injury in anterior cruciate ligament
Advantages of RNA-seq compared to RNA microarrays for transcriptome profiling of anterior cruciate ligament tears.
No sample metadata fields
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