High-protein diets are known to reduce adiposity in the context of high carbohydrate and Western diets. However, few studies have investigated the specific high-protein effect on lipogenesis induced by a high-sucrose (HS) diet or fat deposition induced by high-fat feeding. We aimed to determine the effects of high protein intake on the development of fat deposition and partitioning in response to high-fat and/or HS feeding. A total of thirty adult male Wistar rats were assigned to one of the six dietary regimens with low and high protein, sucrose and fat contents for 5 weeks. Body weight (BW) and food intake were measured weekly. Oral glucose tolerance tests and meal tolerance tests were performed after 4th and 5th weeks of the regimen, respectively. At the end of the study, the rats were killed 2 h after ingestion of a calibrated meal. Blood, tissues and organs were collected for analysis of circulating metabolites and hormones, body composition and mRNA expression in the liver and adipose tissues. No changes were observed in cumulative energy intake and BW gain after 5 weeks of dietary treatment. However, high-protein diets reduced by 20 % the adiposity gain induced by HS and high-sucrose high-fat (HS-HF) diets. Gene expression and transcriptomic analysis suggested that high protein intake reduced liver capacity for lipogenesis by reducing mRNA expressions of fatty acid synthase (fasn), acetyl-CoA carboxylase a and b (Acaca and Acacb) and sterol regulatory element binding transcription factor 1c (Srebf-1c). Moreover, ketogenesis, as indicated by plasma -hydroxybutyrate levels, was higher in HS-HF-fed mice that were also fed high protein levels. Taken together, these results suggest that high-protein diets may reduce adiposity by inhibiting lipogenesis and stimulating ketogenesis in the liver.
High dietary protein decreases fat deposition induced by high-fat and high-sucrose diet in rats.
Sex, Specimen part
View SamplesThe white adipose tissue (WAT) rapidly loses mass when mice are fed a diet containing trans-10, cis-12 conjugated linoleic acid (t10c12 CLA). A microarray analysis of WAT due to CLA feeding was performed to better define the processes and genes involved. WAT weight decreased by ca. 80% over 17 days of feeding a 0.5% t10c12 CLA diet. The lipid volume decreased by 90% and the number of adipocytes and total cells were reduced by15% and 47%, respectively. Microarray profiling of replicated pools of control and treated mice (n=140) at seven time points over the 17day feeding indicated between 2798 to 4318 genes showed mRNA changes of 2-fold or more. Transcript levels for genes of glucose and fatty acid import or biosynthesis were significantly reduced. A prolific inflammation response was indicated by the 2 to100-fold induction of many cytokine transcripts, including those for IL-6, IL1?, TNF ligands, and CXC family members
Trans-10, cis-12 conjugated linoleic acid causes inflammation and delipidation of white adipose tissue in mice: a microarray and histological analysis.
Age
View SamplesTrans-10, cis-12 conjugated linoleic acid (t10c12 CLA) causes dramatic reductions in white adipose tissue in mice but has had limited effectiveness in humans. Determination of the signaling pathways involved may lead to better regulation of adiposity. T10c12 CLA was found to activate AMP-activating protein kinase (AMPK), a central regulator of cell metabolism. Compound C, a potent inhibitor of AMPK, prevents many of the typical responses to treatments with t10c12 CLA including the integrated stress response (ISR), the inflammatory response, the reduction in key lipogenic transcription factors, and delipidation. Treatment of adipocytes or mice with t10c12 CLA in conjunction with AMPK activator metformin results in more delipidation than treatment with the individual chemicals. Additionally, the combination showed a reduced inflammatory response relative to a t10c12 CLA treatment alone. The combination of t10c12 CLA and metformin, widely used to treat insulin resistance and Type II diabetes, has potential as a treatment for reducing adiposity in humans.
Conjugated linoleic acid activates AMP-activated protein kinase and reduces adiposity more effectively when used with metformin in mice.
Cell line
View SamplesActivation of the hypoxia inducible transcription factor HIF-alpha and the NF-kappaB pathway promotes inflammation mediated tumor progression.
The hypoxia-inducible transcription factor ZNF395 is controlled by IĸB kinase-signaling and activates genes involved in the innate immune response and cancer.
Cell line, Treatment
View SamplesThe NF1 tumor suppressor encodes a RAS GTPase-Activating Protein (RasGAP). Accordingly, deregulated RAS signaling underlies the pathogenesis of NF1-mutant cancers. However, while various RAS effector pathways have been shown to function in these tumors, it is currently unclear which specific proteins within these broad signaling pathways represent optimal therapeutic targets. Here we identify mTORC1 as the key PI3K pathway component in NF1-mutant nervous system malignancies and conversely show that mTORC2 and AKT are dispensable. We also report that combined mTORC1/MEK inhibition is required to promote tumor regression in animal models, but only when the inhibition of both pathways is sustained. Transcriptional profiling studies were also used to establish a predictive signature of effective mTORC1/MEK inhibition in vivo. Within this signature, we unexpectedly found that the glucose transporter gene, GLUT1, was potently suppressed but only when both pathways were effectively inhibited. Moreover, unlike VHL and LKB1 mutant cancers, reduction of 18F-FDG uptake measured by FDG-PET required the effective suppression of both mTORC1 and MEK. Together these studies identify optimal and sub-optimal therapeutic targets in NF1-mutant malignancies and define a non-invasive means of measuring combined mTORC1/MEK inhibition in vivo, which can be readily incorporated into clinical trials.
Defining key signaling nodes and therapeutic biomarkers in NF1-mutant cancers.
Specimen part
View SamplesFollowing implantation, mouse epiblast cells transit from a naïve to a primed state in which they are competent for both somatic and primordial germ cell (PGC) specification. Using mouse embryonic stem cells (mESC) as an in vitro model to study the transcriptional regulatory principles orchestrating peri-implantation development, here we show that the transcription factor Foxd3 is necessary for the exit from naïve pluripotency and the progression to a primed pluripotent state. During this transition, Foxd3 acts as a repressor that dismantles a significant fraction of the naïve pluripotency expression program through the decommissioning of active enhancers associated with key naïve pluripotency and early germline genes. Subsequently, Foxd3 needs to be silenced in primed pluripotent cells to allow the reactivation of relevant genes required for proper PGC specification. Our findings uncover a wave of activation-deactivation of Foxd3 as a crucial step for the exit from naïve pluripotency and subsequent PGC specification. Overall design: mRNA profiles were generated by RNA-seq in duplicates for each of the following mESC lines: Foxd3fl/fl;Cre-ER mESC maintained in "Serum+LIF" (SL) treated with TM for three days (SL Foxd3-/-); untreated Foxd3fl/fl;Cre-ER SL mESC (SL Foxd3fl/fl); tetON Foxd3 SL mESC treated with Dox for three days; WT SL mESC treated with Dox for three days; Foxd3fl/fl;Cre-ER mESC maintained in "2i+LIF" (2i) treated with TM for three days (2i Foxd3-/-); untreated Foxd3fl/fl;Cre-ER 2i mESC (2i Foxd3fl/fl).
Foxd3 Promotes Exit from Naive Pluripotency through Enhancer Decommissioning and Inhibits Germline Specification.
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View SamplesActivated AMPK and prostaglandins are involved in the response to conjugated linoleic acid and are sufficient to cause lipid reductions in adipocytes.
Activated AMPK and prostaglandins are involved in the response to conjugated linoleic acid and are sufficient to cause lipid reductions in adipocytes.
Specimen part, Cell line, Treatment
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse 3T3-L1 adipocyte tissue culture. The early transcriptome changes were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse white adipose tissue (WAT). The early transcriptome changes in WAT were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Sex, Specimen part
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse white adipose tissue (WAT) and 3T3-L1 adipocyte tissue culture; however in preadipocyte tissue (this series) the UPS/ISR and fat loss is not detected. The early transcriptome changes in 3T3-L1 preadipocyte tissue culture were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 12 hr after treatment do not show a set of genes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View Samples