We showed that nandrolone attenuated subacute, but not acute, denervation atrophy and upregulation of MAFbx. The present study explored the molecular determinants for this time-dependent effect using microarray analysis to identify genes that were differentially regulated by administration of nandrolone for 7 days beginning either concomitantly with denervation (7 days) or 29 days later (35 days)
Nandrolone normalizes determinants of muscle mass and fiber type after spinal cord injury.
Sex
View SamplesPurpose: The goal of this study was to determine the gene expression changes that occur over 7 days in parralyzed muscle in response to isometric contraction elicited by electrical stimulation initiated 4 months after spinal cord injury and to compare such changes to those observed in a normal muscle subjected to overload.
Electrical stimulation modulates Wnt signaling and regulates genes for the motor endplate and calcium binding in muscle of rats with spinal cord transection.
Sex, Specimen part
View SamplesRNA-seq analysis from young and pre-glaucomatous DBA/2J retinal ganglion cells and control (age and sex-matched, D2-Gpnmb+) retinal ganglion cells Overall design: Retinal ganglion cell mRNA from 4 month (young) and 9 month (pre-glaucomatous) DBA/2J mice and age and sex-matched D2-Gpnmb+ controls
Nicotinamide and WLD<sup>S</sup> Act Together to Prevent Neurodegeneration in Glaucoma.
Cell line, Treatment, Subject
View SamplesGlucocorticoids are a well recognized and common cause of muscle atrophy. Glucocorticoid-induced atrophy can be prevented by testosterone, but the molecular mechanisms underlying such protection have not been described. Thus, the global effects of testosterone on dexamethasone-induced changes in gene expression were evaluated in rat gastrocnemius muscle using Affymetrix 230_2 DNA microarrays. Gene expression was analyzed after 7 days administration of dexamethasone, dexamethasone plus testosterone, or vehicle. Effects of these agents on weights of gastrocnemius muscles from these animals has been reported (1. Zhao W, Pan J, Zhao Z, Wu Y, Bauman WA, and Cardozo CP. Testosterone protects against dexamethasone-induced muscle atrophy, protein degradation and MAFbx upregulation. J Steroid Biochem Mol Biol 110: 125-129, 2008.) Dexamethasone changed expression of 876 probe sets by at least 2-fold, of which 474 probe sets were changed by at least two fold in the opposite direction in the dexamethasone plus testosterone group (genes in opposition). Major biological themes represented by genes in opposition included IGF-1 signaling, protein synthesis, myogenesis and muscle development, and ubiquitin conjugases and ligases. Testosterone blocked increased expression of DDIT4 and eIF4EBP1, FOXO1 and of the p85 regulatory subunit of the IGF-1 receptor, while preventing decreased expression of IRS-1. Testosterone blocked decreased expression of LXR and suppressed upregulation of C/EBP beta and delta. Testosterone prevented increase expression of Cdkn1A (p21) and decrease expression of cyclins B and D, as well as many other changes that would be expected to reduce cell cycle progression. Testosterone prevented increased expression of muscle development factors Csrp3 and Mbn1 and blocked reduced expression of Wnt4. These data suggest that testosterone blocks multiple changes in gene expression that, collectively, would otherwise downregulate molecular signals that promote protein synthesis and muscle hypertrophy and that stimulate muscle protein catabolism.
REDD1 is a major target of testosterone action in preventing dexamethasone-induced muscle loss.
No sample metadata fields
View SamplesSpinal cord injury (SCI) causes severe bone loss and disrupts connections between higher centers in the central nervous system (CNS) and bone. Muscle contraction elicited by functional electrical stimulation (FES) partially protects against loss of bone but cellular and molecular events by which this occurs are unknown. Here, using a rat model, we characterized effects of 7 days of contraction-induced loading of tibia and fibula due to FES when begun 16 weeks after SCI. SCI reduced tibial and femoral BMD by 12-17% and promoted bone resorption, as indicated by increased serum CTX; SCI-related changes in CTX were reversed by FES. In cultures of bone marrow cell-derived cells, SCI increased the number of osteoclasts and mRNA levels of the several osteoclast differentiation markers; these changes were significantly reversed by FES. The number of osteoblasts was also reduced by SCI as was the ratio of OPG/RANKL mRNAs therein; the unfavorable change in OPG/RANKL ratio was partially reversed by FES. cDNA microarray analysis revealed that alterations in genes involved in signaling through Wnt, FSH/LH, PTH and calcineurin/NFAT pathways may be linked to the favorable action of FES on SCI-induced bone resorption. In particular, SCI increased levels of the Wnt inhibitors DKK1, sFRP2 and SOST in osteoblasts, These effects were completely or partially reversed by FES. Our results demonstrate an anti-bone resorptive activity of acute FES in bone loss after SCI and suggest potential underlying mechanisms, among them involving increased Wnt signaling to cause more favorable ratios of OPG and RANKL for the inhibition of osteoclastogenesis. The present study indicates that the effects of bone reloading on SCI- related bone remodeling occurred independently of the effects of higher CNS centers on bone.
The central nervous system (CNS)-independent anti-bone-resorptive activity of muscle contraction and the underlying molecular and cellular signatures.
Sex, Specimen part
View SamplesWe profiled the transcriptome of matched diagnosis and relapse samples from 10 pediatric B precursor Acute Lymphoblastic Leukemia (ALL) patients using massively parallel sequencing (RNA-Seq) technology to identify novel mutations specific at disease recurrence.
Relapse-specific mutations in NT5C2 in childhood acute lymphoblastic leukemia.
No sample metadata fields
View SamplesTumor cells exhibit aberrant metabolism characterized by high glycolysis even in the presence of oxygen. This metabolic reprogramming, known as the Warburg effect, provides tumor cells with the substrates and redox potential required for the generation of biomass. Here, we show that the mitochondrial NAD-dependent deacetylase SIRT3 is a crucial regulator of the Warburg effect. SIRT3 loss promotes a metabolic profile consistent with high glycolysis required for anabolic processes in vivo and in vitro. Mechanistically, SIRT3 mediates metabolic reprogramming independently of mitochondrial oxidative metabolism and through HIF1a, a transcription factor that controls expression of key glycolytic enzymes. SIRT3 loss increases reactive oxygen species production, resulting in enhanced HIF1a stabilization. Strikingly, SIRT3 is deleted in 40% of human breast cancers, and its loss correlates with the upregulation of HIF1a target genes. Finally, we find that SIRT3 overexpression directly represses the Warburg effect in breast cancer cells. In sum, we identify SIRT3 as a regulator of HIF1a and a suppressor of the Warburg effect.
SIRT3 opposes reprogramming of cancer cell metabolism through HIF1α destabilization.
Specimen part
View SamplesTGF is one of most intensively studied regulators of extracellular matrix formation, and has been implicated in the development of pulmonary fibrosis in different models. However, little is know about the role of miRNAs in TGF mediated fibrogenic gene regulation. By using miRNA qRT-PCR array, we have identified miRNAs whose expression are regulated by TGF in IMR-90 cells. Among those down-regulated miRNAs are miR-29 family members. Knockdown miR-29 in IMR-90 cells results in up-regulation of a large number of extracellular matrix and fibrogenic genes including family members of collagen, laminin, integrin, ADAM and MMP, many of them are predicted or confirmed miR-29 targets. Hierarchichal clustering analysis of mRNA array data revealed that many extracellular matrix and fibrogenic genes up-regulated by TGF in IMR-90 cells, are also up-regulated in miR-29 KD cells. Moreover, the similar set of extracellular matrix and fibrogenic genes is also significantly up-regulated in bleomycin treated mouse lungs. Together, our data strongly suggest that downstream of the TGF, miR-29 is a master modulator of genes involved in extracellular matrix formation and might play a significant role in pulmonary fibrosis.
miR-29 is a major regulator of genes associated with pulmonary fibrosis.
Specimen part, Cell line
View SamplesGW182 (Tnrc6a) is a key component of RISC (miRNA-Induced Silencing Complex) that plays a critical role in miRNA-mediated gene silencing. Here, we show that GW182 is expressed in the yolk sac endoderm, and that gene-trap disruption of GW182 leads to growth arrest of yolk sac endoderm, impaired hematopoiesis and embryonic lethality.
Trinucleotide repeat containing 6a (Tnrc6a)-mediated microRNA function is required for development of yolk sac endoderm.
Specimen part
View SamplesMulticiliated cells are crucial for fluid and ion transport in epithelia of a variety of organs and their impaired development and function are seen in human diseases affecting the brain, respiratory, and reproductive tracts. Multiciliogenesis requires activation of a specialized transcription program coupled to complex cytoplasmic events that lead to large-scale centriole amplification to generate multicilia. Yet, it remains unclear how these events are coordinated to initiate multiciliogenesis in epithelial progenitors. Here we identify an unsuspected mechanism orchestrated by the transcription factor E2f4 essential to integrate these processes. We show that after inducing a transcriptional program of centriole biogenesis, E2f4 translocates to the cytoplasm to become a core component of structures classically identified as fibrous granules (FG), acting as organizing centers for deuterosome assembly and centriole amplification. Remarkably, loss of cytoplasmic E2f4 prevents FG aggregation, deuterosome assembly and multicilia formation even when E2f4s transcriptional function is preserved. Moreover, in E2f4-deficient cells multiciliogenesis is rescued only if both nuclear and cytoplasmic E2f4 activities are restored. Thus, E2f4 integrates previously unrelated nuclear and cytoplasmic events of the multiciliated cell program.
Cytoplasmic E2f4 forms organizing centres for initiation of centriole amplification during multiciliogenesis.
Specimen part
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