This SuperSeries is composed of the SubSeries listed below.
Detailed transcriptomics analysis of the effect of dietary fatty acids on gene expression in the heart.
Sex, Treatment
View SamplesFatty acids comprise the primary energy source for the heart and are mainly taken up via hydrolysis of circulating triglyceride-rich lipoproteins. While most of the fatty acids entering the cardiomyocyte are oxidized, a small portion is involved in altering gene transcription to modulate cardiometabolic functions. So far, no in vivo model has been developed enabling study of the transcriptional effects of specific fatty acids in the intact heart. In the present study, mice were given a single oral dose of synthetic triglycerides composed of one single fatty acid. Hearts were collected 6h thereafter and used for whole genome gene expression profiling. Experiments were conducted in wild-type and PPAR/ mice to allow exploration of the specific contribution of PPAR. It was found that: 1) linolenic acid (C18:3) had the most pronounced effect on cardiac gene expression. 2) The largest similarity in gene regulation was observed between linoleic acid (C18:2) and C18:3. Large similarity was also observed between the synthetic PPAR agonist Wy14643 and docosahexaenoic acid (C22:6). 3) Many genes were regulated by one particular treatment only. Genes regulated by one particular treatment showed large functional divergence. 4) The majority of genes responding to fatty acid treatment were regulated in a PPAR-dependent manner, emphasizing the importance of PPAR in mediating transcriptional regulation by fatty acids in the heart. 5) Several genes were robustly regulated by all or many of the fatty acids studied, mostly representing well-described targets of PPARs (e.g. Acot1, Angptl4, Ucp3). 6) Deletion and activation of PPAR had a major effect on expression of numerous genes involved in metabolism and immunity. Our analysis demonstrates the marked impact of dietary fatty acids on gene regulation in the heart via PPAR.
Detailed transcriptomics analysis of the effect of dietary fatty acids on gene expression in the heart.
Sex, Treatment
View SamplesObjective: Nonalcoholic fatty liver disease (NAFLD) is linked to obesity and diabetes, suggesting an important role of adipose tissue in the pathogenesis of NAFLD. Here we aim to investigate the interaction between adipose tissue and liver in NAFLD, and identify potential early plasma markers that predict NASH. Research Design and Methods: C57Bl/6 mice were chronically fed a high fat diet to induce NAFLD and compared with mice fed low fat diet. Extensive histological and phenotypical analyses coupled with a time-course study of plasma proteins using multiplex assay was performed. Results: Mice exhibited pronounced heterogeneity in liver histological scoring, leading to classification into 4 subgroups: LF-low (LFL) responders displaying normal liver morphology, LF-high (LFH) responders showing benign hepatic steatosis, HF-low (HFL) responders displaying pre-NASH with macrovesicular lipid droplets, and HF-high (HFH) responders exhibiting overt NASH characterized by ballooning of hepatocytes, presence of Mallory bodies, and activated inflammatory cells. Compared to HFL responders, HFH mice gained weight more rapidly and exhibited adipose tissue dysfunction characterized by decreased final fat mass, enhanced macrophage infiltration and inflammation, and adipose tissue remodelling. Plasma haptoglobin, IL-1, TIMP-1, adiponectin and leptin were significantly changed in HFH mice. Multivariate analysis indicated that in addition to leptin, plasma CRP, haptoglobin, eotaxin and MIP-1 early in the intervention were positively associated with liver triglycerides. Intermediate prognostic markers of liver triglycerides included IL-18, IL-1, MIP-1 and MIP-2, whereas insulin, TIMP-1, GCP-2 and MPO emerged as late markers. Conclusions: Our data support the existence of a tight relationship between adipose tissue dysfunction and NASH pathogenesis and point to several novel potential predictive biomarkers for NASH.
Adipose tissue dysfunction signals progression of hepatic steatosis towards nonalcoholic steatohepatitis in C57BL/6 mice.
Specimen part
View SamplesTo study the physiological role of WNT4 in the postnatal ovary, a mouse strain bearing a floxed Wnt4 allele was created and mated to the Amhr2tm3(cre)Bhr strain to target deletion of Wnt4 to granulosa cells. Wnt4flox/-;Amhr2tm3(cre)Bhr/+ mice had significantly reduced ovary weights and produced smaller litters (P<0.05). Serial follicle counting demonstrated that, while Wnt4flox/-;Amhr2tm3(cre)Bhr/+ mice were born with a normal ovarian reserve and maintained normal numbers of small follicles until puberty, they had only 25.2% of the normal number of healthy antral follicles. Some Wnt4flox/-;Amhr2tm3(cre)Bhr/+ mice had no antral follicles or corpora lutea and underwent premature follicle depletion. RTPCR analyses of Wnt4flox/-;Amhr2tm3(cre)Bhr/+ granulosa cells and cultured granulosa cells that overexpress WNT4 demonstrated that WNT4 regulates the expression of Star, Cyp11a1 and Cyp19, steroidogenic genes previously identified as downstream targets of the WNT signaling effector CTNNB1. WNT4- and CTNNB1-overexpressing cultured granulosa cells were analyzed by microarray for alterations in gene expression, which showed that WNT4 also regulates a series of genes involved in late follicle development and the cellular stress response via the WNT/CTNNB1 signaling pathway. Together, these data indicate that WNT4 is required for normal antral follicle development, and may act by regulating granulosa cell functions including steroidogenesis.
WNT4 is required for normal ovarian follicle development and female fertility.
Specimen part, Treatment
View SamplesWe wanted to determine how type II versus type III Toxoplasma infection affect host gene expression
Toxoplasma polymorphic effectors determine macrophage polarization and intestinal inflammation.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The requirement for cyclin D function in tumor maintenance.
Specimen part, Cell line
View SamplesD-cyclins represent components of cell cycle machinery. To test the efficacy of targeting D-cyclins in cancer treatment, we engineered mouse strains which allow acute and global ablation of individual D-cyclins in a living animal. Ubiquitous shutdown of cyclin D1 or inhibition of cyclin D associated kinase activity in mice bearing ErbB2-driven mammary carcinomas halted cancer progression and triggered tumor-specific senescence, without compromising the animals' health. Ablation of cyclin D3 in mice bearing T-cell acute lymphoblastic leukemias (T-ALL) triggered tumorspecific apoptosis. Such selective killing of leukemic cells can be also achieved by inhibiting cyclin D associated kinase activity in mouse and human T-ALL models. Hence, contrary to what one might expect from ablation of a cell cycle protein, acute shutdown of a D-cyclin leads not only to cell cycle arrest, but it also triggers tumor cell senescence or apoptosis, and it affects different tumor types through distinct cellular mechanisms. Inhibiting cyclin D-activity represents a highly-selective anticancer strategy which specifically targets cancer cells without significantly affecting normal tissues.
The requirement for cyclin D function in tumor maintenance.
Specimen part
View SamplesRepair of injured muscle involves repair of injured myofibers through the involvement of dysferlin and its interacting partners, including annexin. Studies with mice and patients have established that dysferlin deficit leads to chronic inflammation and adipogenic replacement of the diseased muscle. However, longitudinal analysis of annexin deficit on muscle pathology and function is lacking. Here we show that unlike annexin A1, but similar to dysferlin, lack of annexin A2 (AnxA2) causes poor myofiber repair and progressive weakening with age. However, unlike dysferlin-deficient muscle, AnxA2-deficient muscles do not exhibit chronic inflammation or adipogenic replacement. Deletion of AnxA2 in dysferlin deficient mice reduces inflammation, adipogenic replacement, and loss in muscle function caused by dysferlin deficit. These results show that: a) AnxA2 facilitates myofiber repair, b) chronic inflammation and adipogenic replacement of dysferlinopathic muscle requires AnxA2, and c) inhibiting AnxA2-mediated inflammation is a novel therapeutic avenue for dysferlinopathy.
Annexin A2 links poor myofiber repair with inflammation and adipogenic replacement of the injured muscle.
Age, Specimen part
View SamplesThe aim of the present study was to compare, on a statistical basis, the performance of different microarray platforms to detect differences in gene expression in a realistic and challenging biological setting. Gene expression profiles in the hippocampus of five wild-type and five transgenic C-doublecortin-like kinase mice were evaluated with five microarray platforms: Applied Biosystems, Affymetrix, Agilent, Illumina and home-spotted oligonucleotide arrays. We observed considerable overlap between the different platforms, the overlap being better detectable with significance level-based ranking than with a p-value based cut-off. Confirming the qualitative agreement between platforms, Pathway analysis consistently demonstrated aberrances in GABA-ergic signalling in the transgenic mice, even though pathways were represented by only partially overlapping genes on the different platforms.
Can subtle changes in gene expression be consistently detected with different microarray platforms?
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