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 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 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 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 SamplesThe purpose of this study was to determine whether there were differences in gene expression in the hippocampus, a part of the brain involved in memory consolidation, between male mice with age-related memory deficits (SAMP8 mice) and control mice with no age-related memory deficits. The senescence-accelerated mouse (SAMP8) strain exhibits decreased learning and memory and increased amyloid beta peptide (A) accumulation at 12 months compared to 4 months. To detect differences in gene expression in SAMP8 mice, we used a Control mouse that was a 50% cross between SAMP8 and CD-1 mice and which showed no memory deficits (50% SAMP8 mouse). We then compared gene expression in the hippocampus of 4 month and 12 month old SAMP8 and Control mice using Affymetrix gene arrays. At 12 months, but not at 4 months, pathway analysis revealed significant differences in the Long Term Potentiation (LTP) (6 genes), Phosphatidylinositol Signaling (6 genes), and Endocytosis (10 genes) pathways. The changes in LTP included MAPK signaling (N-ras, CREB binding protein, protein phosphatase inhibitor 1) and Ca-dependent signaling (PI receptors 1 and 2 and phospholipase C). Changes in phosphatidylinositol signaling genes suggested altered signaling through PI3-kinase, and Western blotting revealed phosphorylation changes in AKT and 70S6K. Changes in the Endocytosis pathway involved genes related to clathrin-mediated endocytosis (dynamin and clathrin). Endocytosis is required for receptor recycling, is involved in A metabolism, and is regulated by phosphatidylinositol signaling. In summary, these studies demonstrate altered genes expression in three SAMP8 hippocampal pathways associated with memory formation and consolidation. These pathways may provide new therapeutic targets in addition to targeting A metabolism itself.
No associated publication
Age, Specimen part
View SamplesThe purpose of this study was to determine the effect of peripheral (IV) administration of APP antisense on hippocampal gene expression as well as on learning and memory as measured by T-maze in adult male mice aged 12 months. The APP antisense treatment reversed learning and memory deficits and altered the expression of 944 hippocampal genes, which are involved in a coordinated set of signaling pathways. Expression and pathway findings were verified at the protein and functional (phosphorylation) levels.
No associated publication
Sex, Age, Specimen part
View SamplesThis study examined the effects of castration and testosterone replacement on global differential gene transcription in the gastrocnemius muscle (m.Gas) in young adult mice over 14-days.
No associated publication
Specimen part
View SamplesDetection, treatment, and prediction of outcome for lung cancer patients increasingly depend on a molecular understanding of tumor development and sensitivity of lung cancer to therapeutic drugs. The application of genomic technologies, such as microarray, is widely used to monitor global gene expression and has built up invaluable information and knowledge, which is essential to the discovery of new insights into the mechanisms common to cancer cells, resulting in the identification of unique, identifiable signatures and specific characteristics. It is likely that application of microarray may revolutionize many aspects of lung cancer being diagnosed, classified, and treated in the near future. We used microarrays to detail the global gene expression patterns of lung cancer.
Selection of DDX5 as a novel internal control for Q-RT-PCR from microarray data using a block bootstrap re-sampling scheme.
Sex
View Samples'Precision medicine' is a concept that by utilizing modern molecular diagnostics, an effective therapy is accurately applied for each cancer patient to improve their survival rates. The aim of this study was to compare the molecular subtypes of triple negative breast cancer (TNBC) between Taiwanese and other datasets.
A comparison of the molecular subtypes of triple-negative breast cancer among non-Asian and Taiwanese women.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Liver Gene Expression Profiles Correlate with Virus Infection and Response to Interferon Therapy in Chronic Hepatitis B Patients.
Sex, Age, Specimen part
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