Dietary collagen hydrolysate has been conjectured to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsic aged mice. Female 9-week-old hairless mice were fed a control diet, or a collagen hydrolysate-containing diet, for 12 weeks. The stratum corneum water content and skin elasticity were sequentially decreased by chronological aging in control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we comprehensively analyzed gene expression in the skin of mouse, which had been administered collagen hydrolysate, using DNA microarray. Twelve weeks after start of collagen intake, no significant differences appeared in gene expression profile compared to that of control group. However, 1 week after administration, 135 genes were up-regulated and 448 genes were down-regulated in collagen group compared to control group. It is indicate that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms, especially related to epidermal cell development, were signicantly enriched in up-regulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation and suppress dermal degradation. Thus, dietary collagen hydrolysate induced positive gene changes. In conclusion, our results suggest that alteration of gene expression at early stages after collagen administration affect skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of the skin tissue.
Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis.
Sex, Age, Specimen part, Treatment
View SamplesHistone H3 lysine 9 (H3K9) methylation is an epigenetic mark of transcriptionally repressed chromatin. During mammalian development, H3K9 methylation levels seem to be spatiotemporally regulated by the opposing activities of methyltransferases and demethylases to govern correct gene expression. However, the combination(s) of H3K9 methyltransferase(s) and demethylase(s) that contribute to this regulation and the genes regulated by them remain unclear. Herein, we demonstrate the essential roles of H3K9 demethylases Jmjd1a and Jmjd1b in the embryogenesis and viability control of embryonic stem (ES) cells. Mouse embryos lacking Jmjd1a/Jmjd1b died after implantation. Depletion of Jmjd1a/Jmjd1b in mouse ES cells induced rapid cell death accompanied with a massive increase in H3K9 methylation. Jmjd1a/Jmjd1b depletion induced an increase in H3K9 methylation in the gene-rich regions of the chromosomes, indicating that Jmjd1a/Jmjd1b removes H3K9 methylation marks in the euchromatin. Importantly, the additional disruption of the H3K9 methyltransferase G9a in a Jmjd1a/Jmjd1b-deficient background rescued not only the H3K9 hypermethylation phenotype but also the cell death phenotype. We also found that Jmjd1a/Jmjd1b removes H3K9 methylation marks deposited by G9a in the Oct4 and Ccnd1 loci to activate transcription. In conclusion, Jmjd1a/Jmjd1b ensures ES cell viability by antagonizing G9a-mediated H3K9 hypermethylation in the gene-rich euchromatin.
Combined Loss of JMJD1A and JMJD1B Reveals Critical Roles for H3K9 Demethylation in the Maintenance of Embryonic Stem Cells and Early Embryogenesis.
Specimen part
View SamplesIngestion of collagen peptide elicits beneficial effects on the body. Improvement of blood lipid is one of the effects, but its mechanism remains unclear. Male BALB/cCrSlc mice were bred with the AIN-93M diet containing 14% casein or AIN-93M-based low-protein diet containing 10% casein or diet containing 6% casein+4% collagen peptide (n=12/group) for 10 weeksTotal, free, and esterified cholesterol levels in the blood decreased in the collagen peptide group. DNA microarray analysis of the liver revealed that expression of the genes related to lipid metabolic process, such as PPAR signaling pathway and fatty acid metabolism, increased in the collagen peptide group compared to the 10% casein group. In contrast, expression of the genes related to unfolded protein response (UPR) and protein level of phospho-IRE1 decreased. Our data suggest that lipid metabolism in the liver was altered by collagen ingestion, which probably results in the decreased levels of blood cholesterol.
Collagen peptide ingestion alters lipid metabolism-related gene expression and the unfolded protein response in mouse liver.
Sex, Age, Specimen part
View SamplesSocial stress is well known to be involved in the occurrence and exacerbation of mental illness, and also various life-style related diseases such as hyperinsulinemia, hyperglycemia, cardiovascular diseases and cancer. However, there is little information on tissue-specific gene expression in response to social stress, which reflects our daily life. Liver is one of the most important organs, owing to its biological functions such as energy metabolic homeostasis, metabolization and detoxification of endo- and exogenous substances. In order to elucidate the mechanism underlying response to social stress in the liver, we investigated hepatic gene expression in mice exposed to isolation stress using DNA microarray. Male BALB/c mice (4 weeks old) were housed 5 per cage for 10 days acclimatization. Then mice were exposed to isolation stress for 30 days. After stress treatment, the mouse liver RNA was subjected to DNA microarray analysis. Taking the false discovery rate into account, isolation stress altered expression of 420 genes. Moreover, Gene Ontology analysis of these differentially expressed genes indicated that isolation stress remarkably down-regulated lipid metabolism-related pathway through peroxisome proliferator-activated receptor-alpha (PPARalpha), while lipid biosynthesis pathway regulated by sterol regulatory element binding factor-1 (SREBF-1), Golgi vesicle transport and secretory pathway-related genes were significantly up-regulated. These results suggested that isolation for 30 days, mild and consecutive social stress, not only regulate the systems for lipid metabolism but also cause the endoplasmic reticulum stress in mouse liver.
No associated publication
Sex, Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Exploiting microRNA and mRNA profiles generated in vitro from carcinogen-exposed primary mouse hepatocytes for predicting in vivo genotoxicity and carcinogenicity.
Specimen part, Compound
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrating factor analysis and a transgenic mouse model to reveal a peripheral blood predictor of breast tumors.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Experimentally derived metastasis gene expression profile predicts recurrence and death in patients with colon cancer.
Sex, Age, Disease stage, Race
View SamplesThe well-defined battery of in vitro systems applied within chemical cancer risk assessment is often characterised by a high false-positive rate, thus repeatedly failing to correctly predict the in vivo genotoxic and carcinogenic properties of test compounds. Toxicogenomics, i.e. mRNA-profiling, has been proven successful in improving the prediction of genotoxicity in vivo and the understanding of underlying mechanisms. Recently, microRNAs have been discovered as post-transcriptional regulators of mRNAs. It is thus hypothesised that using microRNA response-patterns may further improve current prediction methods. This study aimed at predicting genotoxicity and non-genotoxic carcinogenicity in vivo, by comparing microRNA- and mRNA-based profiles, using a frequently applied in vitro liver model and exposing this to a range of well-chosen prototypical carcinogens. Primary mouse hepatocytes (PMH) were treated for 24 and 48h with 21 chemical compounds [genotoxins (GTX) vs. non-genotoxins (NGTX) and non-genotoxic carcinogens (NGTX-C) versus non-carcinogens (NC)]. MicroRNA and mRNA expression changes were analysed by means of Exiqon and Affymetrix microarray-platforms, respectively. Classification was performed by using Prediction Analysis for Microarrays (PAM). Compounds were randomly assigned to training and validation sets (repeated 10 times). Before prediction analysis, pre-selection of microRNAs and mRNAs was performed by using a leave-one-out t-test. No microRNAs could be identified that accurately predicted genotoxicity or non-genotoxic carcinogenicity in vivo. However, mRNAs could be detected which appeared reliable in predicting genotoxicity in vivo after 24h (7 genes) and 48h (2 genes) of exposure (accuracy: 90% and 93%, sensitivity: 65% and 75%, specificity: 100% and 100%). Tributylinoxide and para-Cresidine were misclassified. Also, mRNAs were identified capable of classifying NGTX-C after 24h (5 genes) as well as after 48h (3 genes) of treatment (accuracy: 78% and 88%, sensitivity: 83% and 83%, specificity: 75% and 93%). Wy-14,643, phenobarbital and ampicillin trihydrate were misclassified. We conclude that genotoxicity and non-genotoxic carcinogenicity probably cannot be accurately predicted based on microRNA profiles. Overall, transcript-based prediction analyses appeared to clearly outperform microRNA-based analyses.
Exploiting microRNA and mRNA profiles generated in vitro from carcinogen-exposed primary mouse hepatocytes for predicting in vivo genotoxicity and carcinogenicity.
Specimen part, Compound
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Evaluating microRNA profiles reveals discriminative responses following genotoxic or non-genotoxic carcinogen exposure in primary mouse hepatocytes.
Specimen part, Compound
View SamplesSpecification of germ cell fate is fundamental in development. With a highly representative single-cell microarray and rigorous quantitative-PCR analysis, we defined the genome-wide transcription dynamics that create primordial germ cells (PGCs) from the epiblast, a process that exclusively segregates them from their somatic neighbors. We also analyzed the effect of the loss of Blimp1, a key transcriptional regulator, on these dynamics. Our analysis revealed that PGC specification involves complex, yet highly ordered regulation of a large number of genes, proceeding under the strong influence of mesoderm induction with active repression of specific programs such as epithelial-mesenchymal transition, Hox gene activation, cell-cycle progression and DNA methyltransferase machinery. Remarkably, Blimp1 is essential for repressing nearly all the genes normally down-regulated in PGCs relative to their somatic neighbors, whereas it is dispensable for the activation of approximately half of the genes up-regulated in PGCs.
No associated publication
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