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GSE34773
Mus musculus
22 Downloadable Samples
Description
Calorie restriction (CR) is a dietary intervention that extends lifespan and healthspan in a variety of organisms. CR improves mitochondrial energy production, fuel oxidation and reactive oxygen species scavenging in skeletal muscle and other tissues, and these processes are thought to be critical to the benefits of CR. PGC-1a is a transcriptional coactivator that regulates mitochondrial function and is induced by CR. Consequently, many of the mitochondrial and metabolic benefits of CR are attributed to increased PGC-1a activity. To test this model for the first time, we examined the metabolic and mitochondrial response to CR in mice lacking skeletal muscle PGC-1a (MKO). Surprisingly, MKO mice demonstrated a normal improvement in glucose homeostasis in response to CR, indicating that skeletal muscle PGC-1a is dispensable for the whole-body benefits of CR. In contrast, gene expression profiling and electron microscopy demonstrated that PGC-1a is required for the full CR-induced increases in mitochondrial gene expression and mitochondrial density in skeletal muscle. These results demonstrate that PGC-1a is a major regulator of the mitochondrial response to CR in skeletal muscle, but surprisingly show that neither PGC-1a nor mitochondrial biogenesis in skeletal muscle are required for the metabolic benefits of CR.
Publication Title
Skeletal muscle transcriptional coactivator PGC-1α mediates mitochondrial, but not metabolic, changes during calorie restriction.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 9 Downloadable Samples
Description
Tumor cells exhibit aberrant metabolism characterized by high glycolysis even in the presence of oxygen. This metabolic reprogramming, known as the Warburg effect, provides tumor cells with the substrates and redox potential required for the generation of biomass. Here, we show that the mitochondrial NAD-dependent deacetylase SIRT3 is a crucial regulator of the Warburg effect. SIRT3 loss promotes a metabolic profile consistent with high glycolysis required for anabolic processes in vivo and in vitro. Mechanistically, SIRT3 mediates metabolic reprogramming independently of mitochondrial oxidative metabolism and through HIF1a, a transcription factor that controls expression of key glycolytic enzymes. SIRT3 loss increases reactive oxygen species production, resulting in enhanced HIF1a stabilization. Strikingly, SIRT3 is deleted in 40% of human breast cancers, and its loss correlates with the upregulation of HIF1a target genes. Finally, we find that SIRT3 overexpression directly represses the Warburg effect in breast cancer cells. In sum, we identify SIRT3 as a regulator of HIF1a and a suppressor of the Warburg effect.
Publication Title
SIRT3 opposes reprogramming of cancer cell metabolism through HIF1α destabilization.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
Description
Using killer cell lectin-like receptor G1 as a marker to distinguish terminal effector cells from memory precursors, we found that despite their diverse cell fates both subsets possessed remarkably similar gene expression profiles and functioned as equally potent killer cells. However, only the memory precursors were capable of making IL-2 thus defining a novel effector cell that was cytotoxic, expressed granzyme B, and produced inflammatory cytokines in addition to IL-2. This effector population then differentiated into long-lived protective memory T cells capable of self-renewal and rapid re-call responses. Mechanistic studies showed that cells that continued to receive antigenic stimulation during the later stages of infection were more likely to become terminal effectors. Importantly, curtailing antigenic stimulation towards the tail-end of the acute infection enhanced the generation of memory cells. These studies support the decreasing potential model of memory differentiation and show that the duration of antigenic stimulation is a critical regulator of memory formation
Publication Title
Functional and genomic profiling of effector CD8 T cell subsets with distinct memory fates.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 11 Downloadable Samples
Description
CD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells.
Publication Title
Prolonged interleukin-2Ralpha expression on virus-specific CD8+ T cells favors terminal-effector differentiation in vivo.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 10 Downloadable Samples
Description
A soy diet worsens the progression of an inherited form of hypertrophic cardiomyopathy (HCM) in male mice when compared to casein-fed mice. Females are largely resistant to this diet effect and better preserve cardiac function. We hypothesized that the abundant phytoestrogens found in soy are mainly responsible for this diet-dependent phenotype. Indeed, feeding male mice a phytoestrogen-supplemented casein-based diet can recapitulate the negative outcome seen when male mice are fed a standard soy-based diet.
Publication Title
Estrogenic compounds are not always cardioprotective and can be lethal in males with genetic heart disease.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 15 Downloadable Samples
Description
Induced pluripotent stem (iPS) cells were produced from reprogramming of somatic cells, and they are shown to possess pluripotent properties similar to embryonic stem (ES) cells. Here we used microarrays to detail the global expression pattern among the ES cells and iPS cells, as well as the original mouse embryo fibroblast (MEF), to identify important players involved in the reprogramming process.
Publication Title
iPS cells produce viable mice through tetraploid complementation.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 20 Downloadable Samples
Description
Inflammation has pleiotropic effects on carcinogenesis and tumor progression. Signaling through the adaptor protein MyD88 promotes carcinogenesis in several chemically induced cancer models. Interestingly, we observed a protective role for MyD88 in the development of AOM/DSS colitis-associated cancer. The inability of Myd88-/- mice to heal ulcers generated upon injury creates an inflammatory environment that increases the frequency of mutations and results in a dramatic increase in adenoma formation and cancer progression. Susceptibility to colitis development and enhanced polyp formation were also observed in Il18-/- mice upon AOM/DSS treatment, suggesting that the phenotype of MyD88 knockouts is in part due to their inability to signal through the IL-18 receptor. This study revealed a previously unknown level of complexity surrounding MyD88 activities downstream of different receptors that differentially impact tissue homeostasis and carcinogenesis.
Publication Title
MyD88-mediated signaling prevents development of adenocarcinomas of the colon: role of interleukin 18.
Sample Metadata Fields
Specimen part, Disease, Disease stage
View Samples- Mus musculus
- 6 Downloadable Samples
Description
To clarify inflammatory genes whose expression is suppressed at high temperatures, we performed comprehensive analysis of gene expression by using a DNA microarray. Two independent primary cultures of mouse embryo fibroblasts (MEF1 and MEF2) were treated with LPS for 4 hours, or treated with LPS for 4 hours after the pretreatment with heat shock at 42C for 1 hour, and we identified 100 genes that undergo more than a 3-fold increase with LPS treatment. Remarkably, 86 genes (86%) underwent less than a 2-fold increase after combined treatments with heat shock and LPS in MEF1 and MEF2 cells.
Publication Title
Heat shock transcription factor 1 inhibits expression of IL-6 through activating transcription factor 3.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
Description
Understanding the response of memory CD8 T cells to persistent antigen re-stimulation and the role of CD4 T cell help is critical to the design of successful vaccines for chronic diseases. However, studies comparing the protective abilities and qualities of memory and nave cells have been mostly performed in acute infections, and little is known about their roles during chronic infections. Herein, we show that memory cells dominate over nave cells and are protective when present in large enough numbers to quickly reduce infection. In contrast, when infection is not rapidly reduced, memory cells are quickly lost, unlike nave cells. This loss of memory cells is due to (i) an early block in cell proliferation, (ii) selective regulation by the inhibitory receptor 2B4, and (iii) increased reliance on CD4 T cell help. These findings have important implications towards the design of T cell vaccines against chronic infections and tumors.
Publication Title
Tight regulation of memory CD8(+) T cells limits their effectiveness during sustained high viral load.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
Description
CD4+ T cell help is critical for optimal CD8+ T cell expansion after priming in many experimental systems. However, a role for CD4+ T cells in regulating the initial steps of CD8+ T cell effector differentiation is not well established. Here we demonstrate that absence of CD4+ T cells at the time of replication-incompetent adenovirus vector immunization of C57BL/6 mice led to immediate CD8+ T cell dysfunction characteristic of exhaustion at the first detectable timepoints as well as impaired expansion of antigen-specific CD8+ T cells. The absence of CD4+ T cell help resulted in antigen-specific CD8+ T cells that had reduced ex vivo cytotoxicity and decreased capacity to produce IFN- and TNF-. CD8+ T cells primed in the absence of CD4+ T cells expressed elevated levels of the inhibitory receptors PD-1, LAG-3, and Tim-3, and these cells exhibited transcriptomic exhaustion profiles by gene set enrichment analysis. This dysfunctional state was imprinted within 3 days of immunization and could not be reversed by provision of CD4+ T cell help after priming. Partial rescue of unhelped CD8+ T cell expansion and effector differentiation could be achieved by PD-1 pathway blockade or recombinant IL-2 administration.
Publication Title
Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells.
Sample Metadata Fields
Specimen part, Time
View Samples