We have investigated the effects of CDK8/19 inhibitor Senexin B on NF?B-mediated transcription, induced by a canonical NF?B activator, TNFa. Overall design: HCT116 cells were pre-treated with or without 1 µM Senexin B for 1 hour, followed by 2 hour treatment with 10 ng/ml TNFa. Each treatment condition was done in biological triplicate.
CDK8/19 Mediator kinases potentiate induction of transcription by NFκB.
Cell line, Treatment, Subject
View Samplesp21 (CDKN1A) expression from an IPTG-inducible promoter in HT1080 p21-9 cells was previously shown to inhibit a set of genes, many of which are involved in cell cycle progression, and to upregulate another set of genes, some of which have been implicated in cancer and age-related diseases. We have now developed Senexin A, a small-molecule inhibitor of p21-induced transcription, which we found to be a selective inhibitor of CDK8 and CDK19. Here we tested the effect of Senexin A on the induction and inhibition of transcription by p21.
Cyclin-dependent kinase 8 mediates chemotherapy-induced tumor-promoting paracrine activities.
Specimen part
View SamplesThe cyclin-dependent kinase inhibitor p21WAF1/Cip1 is the prototype downstream effector of the tumor suppressor protein p53. Yet, evidence from human cancer and mice models, imply that p21WAF1/Cip1, under certain conditions, can exercise oncogenic activity. The mechanism behind this behavior is still obscure. Within this context we unexpectedly noticed, predominantly in p53 mutant human cancers, that a subset of highly atypical cancerous cells expressing strongly p21WAF1/Cip1 demonstrated also signs of proliferation. This finding suggests either tolerance to high p21WAF1/Cip1 levels or that p21WAF1/Cip1 per se guided a selective process that led to more aggressive off-springs. To address the latter scenario we employed p21WAF1/Cip1-inducible p53-null cellular models and monitored them over a prolonged time period, using high-throughput screening means. After an initial phase characterized by stalled growth, mainly due to senescence, a subpopulation of p21WAF1/Cip1 cells emerged, demonstrating increased genomic instability, aggressiveness and chemo-resistance. At the mechanistic level unremitted p21WAF1/Cip1 production saturates the CRL4CDT2 and SCFSkp2 ubiquitin ligase complexes reducing the turn-over of the replication licensing machinery. Deregulation of replication licensing triggered replication stress fuelling genomic instability. Conceptually, the above notion should be considered when anti-tumor strategies are designed, since p21WAF1/Cip1 responds also to p53-independent signals, including various chemotherapeutic compounds.
Chronic p53-independent p21 expression causes genomic instability by deregulating replication licensing.
Specimen part, Cell line
View SamplesMost commonly used models of non-alcoholic steatohepatitis (NASH) are diets based on specific gene knockouts or represent extreme manipulations of diet. We have examined the effects of modest increased caloric intake and high dietary unsaturated fat content on the development of NASH in male rats using a model in which overfeeding is accomplished via intragastric infusion of liquid diets as a part of total enteral nutrition. Male Sprague dawley rats were fed diets 5% corn oil containing diets at 187 Kcal/kg3/4/d or fed 70% corn oil containing diets at 220 Kcal/kg3/4/d for a period of 3 weeks. Hepatic gene expression were assessed at the end of the study. Our results indicate that overfeeding of high unsaturated fat diets leads to pathological, endocrine and metabolic changes characteristic of NASH patients and is associated with increased oxidative stress and TNF-a.
A new model for nonalcoholic steatohepatitis in the rat utilizing total enteral nutrition to overfeed a high-polyunsaturated fat diet.
No sample metadata fields
View SamplesThere are concerns regarding possible reproductive toxicity from consumption of soy including an increased risk of endometriosis and endometrial cancer. We used global uterine gene expression profiles in adult ovariectomized (OVX) female rats assessed by RNAseq to examine the estrogenicity of soy protein isolate (SPI) and the potential for feeding SPI to alter estrogen signaling in the uterus. Rats were fed AIN93G diets made with casein (CAS) or SPI from postnatal day (PND) 30. Rats were OVX on PND 50 and infused with 17 beta-estradiol (E2) or vehicle. E2 increased uterine wet weight (P<0.05) and significantly altered expression of 2084 uterine genes. In contrast, SPI feeding had no effect on uterine weight and only altered expression of 177 genes. Overlap between E2 and SPI genes was limited to 69 genes (3%). GO analysis indicated significant differences in uterine biological processes affected by E2 and SPI and little evidence for recruitment of ER alpha to the promoters of ER-responsive genes after SPI feeding. The major E2 up-regulated uterine pathways were cancer pathways and extracellular organization. SPI feeding up-regulated uterine PPAR signaling and fatty acid metabolism. The combination of E2 and SPI feeding resulted in significant regulation of 715 fewer genes relative to E2 alone. In a separate experiment, the combination of E2 and SPI reversed the ability of E2 to induce uterine proliferation in response to the carcinogen dimethybenz(a)anthracene (DMBA). These data suggest SPI does not act as a weak estrogen in the uterus but appears to be a selective estrogen receptor modulator (SERM) interacting with a small sub-set of E2-regulated genes and to be anti-estrogenic in the presence of endogenous estrogens. Overall design: Rat uterus mRNA of ovariectomized adult female rats subject to four different diets (Caseine, Caseine + E2, Soy and Soy+E2 ) were sequenced, in triplicate, in an Illumina GAIIx sequencer.
RNA-sequencing data analysis of uterus in ovariectomized rats fed with soy protein isolate, 17β-estradiol and casein.
No sample metadata fields
View SamplesAppropriate nutrition during early development is essential for optimal bone mass accretion; however, linkage between early nutrition, childhood bone mass and prevention of bone loss later in life has not been extensively studied. In this report, we have demonstrated several fundamental issues in the field. 1) A significant prevention of ovariectomy (OVX) -induced bone loss from adult rats can occur with only 14 days consumption of a blueberry-containing diet immediately prior to puberty. 2) The molecular mechanisms underlying these effects involve increased myosin production and preserved a shuttle for transcription factors such as Runx2 from cytoplasm to nucleolus which stimulates osteoblast differentiation and reduces mesenchymal stromal cell senescence. 3) The effects of blueberry diet on preserving fidelity of osteoblast differentiation also overcome reduced osteoblast differentiation and activity due to OVX-induced degradation of collagen matrix.
Feeding blueberry diets in early life prevent senescence of osteoblasts and bone loss in ovariectomized adult female rats.
Sex, Specimen part
View SamplesSoy foods have been suggested to have both positive health benefits and potentially adverse effects largely as a result of their content of isoflavone phytoestrogens. Since soy protein isolate (SPI) contains isoflavones, in addition to purported health benefits, safety concerns have been raised regarding the use of SPI and soy formulas, because of potential estrogenic actions during the neonatal period, including the potential for reproductive toxicity, infertility, and the possibility of increased risk for development and recurrence of estrogen sensitive cancers such as breast cancer. In the current study, we used a rat model to compare the effects of SPI with those of 17b-estradiol (E2), on global gene expression profiles and morphology in the female rat mammary gland. Rats were either fed AIN-93G diets containing casein (CAS) or SPI beginning on postnatal day (PND) 30.
Mammary gland morphology and gene expression differ in female rats treated with 17β-estradiol or fed soy protein isolate.
Sex
View SamplesThe majority of babies in the US are formula-fed instead of breast fed. There are major differences in the composition of formulas and breast milk and yet little is known about metabolic differences in babies as the result of feeding these very different diets and how that might affect development or disease risk in later life. One concern is that soy-based formulas might have adverse health effects in babies as a result of the presence of low levels of estrogenic phytochemicals genistein and daidzein which are normally present in soy beans. In the current study, we used a piglet model to look at this question. Piglets were either fed breast milk from the sow or were fed two different infant formulas (cows milk-based or soy-based) from age 2 days to 21 days when pigs are normally weaned onto solid food. Blood glucose and lipids were measured. Formula-fed pigs were found to have lower cholesterol than breast fed piglets and in addition had larger stores of iron in their liver.Microarray analysis was carried out to see if changes in liver gene expression could explain these effects of formula feeding. It was found that overall gene expression profiles were influenced by formula feeding compared to breast fed neonates. Gender-independent and unique effects of formula influenced cholesterol and iron metabolism. Further, soy formula feeding in comparison to milk-based formula failed to reveal any estrogenic actions on hepatic gene expression in either male or female pigs.
Formula feeding alters hepatic gene expression signature, iron and cholesterol homeostasis in the neonatal pig.
Sex
View SamplesThe current study was designed to determine if dietary fatty acid concentration and composition affects the development and progression of nonalcoholic fatty liver disease. Male SD rats were overfed diets low (5%) or high (70%) fat diets via total enteral nutrition where the fat source was olive oil (monounsaturated), or corn oil (polyunsaturated). Overfeeding 5% corn oil produced little steatosis relative to feeding 5% olive oil. This was associated with lower fatty acid synthesis and reduced SREBP-c signaling in the 5% corn oil group. Overfeeding 70% fat diets increased steatosis and lead to increased liver necrosis in the 70% corn oil but not olive oil group. Increased injury after feeding polyunsaturated fat diets was linked to peroxidizability of hepatic free fatty acids and triglycerides and appearance of peroxidaized lipid products HETES and HODES previously linked to clinical nonalcoholic steatohepatitis.
Dietary fat source alters hepatic gene expression profile and determines the type of liver pathology in rats overfed via total enteral nutrition.
Sex
View SamplesIn order to properly understand whether xenoestrogens act as estrogens, it is essential to possess a solid portrait of the physiological effects of exogenous estradiol. Because the estrogen-dependent gene expression is one of the primary biomarkers of estrogenic action, we have assessed effects of three doses of exogenous estradiol (0.1, 1.0 and 10 g/kg of body weight/day) on the mammary gland morphology and gene expression profiles by microarray analysis of prepubertal male and female rats of both sexes compared to untreated controls. Estradiol was administered subcutaneously with minipumps from weaning at PND21 to the end of the experiment at PND33. The data suggest that the male mammary is a sensitive tissue for estrogenicity assessment.
Mammary gland morphology and gene expression signature of weanling male and female rats following exposure to exogenous estradiol.
Sex
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