The transcription factor NF-E2-related factor 2 (Nrf2) induces cytoprotective genes, but has also been linked to the regulation of hepatic energy metabolism. In order to assess the pharmacological potential of hepatic Nrf2 activation in metabolic disease, Nrf2 was activated over 8 weeks in mice on Western diet using two different siRNAs against kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2. Whole genome expression analysis followed by pathway analysis demonstrated that the suppression of Keap1 expression induced genes that are involved in anti-oxidative stress defense and biotransformation, pathways proving the activation of Nrf2 by the siRNAs against Keap1. The expression of neither fatty acid- nor carbohydrate-handling proteins was regulated by the suppression of Keap1. Metabolic profiling of the animals did also not show effects on plasma and hepatic lipids, energy expenditure or glucose tolerance by the activation of Nrf2. The data indicate that hepatic Nrf2 is not a major regulator of intermediary metabolism in mice.
Chronic Activation of Hepatic Nrf2 Has No Major Effect on Fatty Acid and Glucose Metabolism in Adult Mice.
Specimen part, Treatment
View SamplesDevelopment of systems allowing the maintenance of native properties of mesenchymal stromal cells (MSC) is a critical challenge for studying physiological functions of skeletal progenitors, as well as towards cellular therapy and regenerative medicine applications. Conventional stem cell culture in monolayer on plastic dishes (2D) is associated with progressive loss of functionality, likely due to the absence of a biomimetic microenvironment and the selection of adherent populations. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow cells within the pores of 3D scaffolds in a perfusion-based bioreactor system, followed by enzymatic digestion for cell retrieval. The 3D-perfusion system supported MSC growth while maintaining cells of the hematopoietic lineage, and thus generated a cellular environment mimicking some features of the bone marrow stroma. As compared to 2D-expansion, sorted CD45- cells derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7-8 doublings) maintained a 4.3-fold higher clonogenicity and exhibited a superior differentiation capacity towards all typical mesenchymal lineages, with similar immunomodulatory function in vitro. Transcriptomic analysis performed on MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability as well as a significant upregulation of multipotency-related gene clusters following 3D-perfusion as compared to 2D expansion. The described system offers a model to study how factors of a 3D engineered niche may regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems.
Expansion of human mesenchymal stromal cells from fresh bone marrow in a 3D scaffold-based system under direct perfusion.
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View SamplesUtilizing glycerol and cardiotoxin (CTX) injections in the tibialis anterior muscles of M. musculus provides models of skeletal muscle damages followed by skeletal muscle regeneration. In particular, glycerol-induced muscle regeneration is known to be associated with ectopic adipogenesis. We characterized genome-wide expression profiles of tibialis anterior muscles from wild-type mice injured by either glycerol or CTX injection. Our goal was to detect gene expression changes during the time course of glycerol-induced and CTX-induced muscle regeneration models, that can lead to ectopic adipocyte accumulation.
Genomic profiling reveals that transient adipogenic activation is a hallmark of mouse models of skeletal muscle regeneration.
Sex, Age, Specimen part
View SamplesAge-related frailty may in part be due to a decreased competency in skeletal muscle regeneration. The role of the closely related TGFbeta amily molecules myostatin and GDF11 in regeneration is unclear. The commercially available antibody which in a prior report was used to demonstrate an age-related decrease in GDF11 was found to detect both GDF11 and myostatin, and with this reagent it appears that the combination of GDF11 and myostatin increases with age in serum. Mechanistically, GDF11 and myostatin induce SMAD2/3 phosphorylation, and both inhibit myoblast differentiation and regulate identical downstream signaling. GDF11 injected into adult mice in a model of regeneration induces an increase in smaller fibers and a decrease in satellite cell expansion. There are no signs of benefit from GDF11 to regeneration. Thus, GDF11 appears to be an age-associated myokine that inhibits muscle differentiation, and is thus a target for blockade to treat frailty
GDF11 Increases with Age and Inhibits Skeletal Muscle Regeneration.
Treatment, Time
View SamplesWe aimed to analyze the effects of Wnt-1 overexpression on the mRNA expression profile of human melanoma in a mouse xenograft model and correlated the results with then presence or absence of lymphangiogenesis and metastasis. Affymetrix gene expression analysis revealed activation of canonical and non-canonical targets genes in response to Wnt-1 as compared with controls. In regard to lymphangiogenic factors, the amount of VEGF-C was the single best marker to correlate with the amount of lymph-angiogenesis.
Wnt1 is anti-lymphangiogenic in a melanoma mouse model.
Cell line, Treatment
View SamplesMolecular mechanisms underlying sarcopenia, the age-related loss of skeletal muscle mass and function, remain unclear. To identify molecular changes that correlated best with sarcopenia and might contribute to its pathogenesis, we determined global gene expression profiles in muscles of rats aged 6, 12, 18, 21, 24, and 27 months. These rats exhibit sarcopenia beginning at 21 months. Correlation of the gene expression versus muscle mass or age changes, and functional annotation analysis identified gene signatures of sarcopenia distinct from gene signatures of aging. Specifically, mitochondrial energy metabolism (e.g., tricarboxylic acid cycle and oxidative phosphorylation) pathway genes were the most downregulated and most significantly correlated with sarcopenia. Also, perturbed were genes/pathways associated with neuromuscular junction patency (providing molecular evidence of sarcopenia-related functional denervation and neuromuscular junction remodeling), protein degradation, and inflammation. Proteomic analysis of samples at 6, 18, and 27 months confirmed the depletion of mitochondrial energy metabolism proteins and neuromuscular junction proteins. Together, these findings suggest that therapeutic approaches that simultaneously stimulate mitochondrogenesis and reduce muscle proteolysis and inflammation have potential for treating sarcopenia.
Genomic and proteomic profiling reveals reduced mitochondrial function and disruption of the neuromuscular junction driving rat sarcopenia.
Sex, Age, Specimen part
View SamplesUnderstanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy.
Knockdown of MTDH sensitizes endometrial cancer cells to cell death induction by death receptor ligand TRAIL and HDAC inhibitor LBH589 co-treatment.
Disease, Disease stage, Cell line
View SamplesUnderstanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy.
Knockdown of MTDH sensitizes endometrial cancer cells to cell death induction by death receptor ligand TRAIL and HDAC inhibitor LBH589 co-treatment.
Specimen part, Cell line
View SamplesTo examine whether MTDH is a novel RNA binding protein and regulates either metabolism or translation of various mRNAs, we performed a RNA-binding protein immunoprecipitation (RIP) with MTDH and IgG antibodies, and the resulting immunoprecipitated RNA was subjected to a microarray to identify transcripts associating with MTDH. In addition we tested the effect of PI3K inhibition using BEZ235 (a dual PI3K/mTOR inhibitor) on the association of MTDH with target mRNAs.
Cytoplasmic Metadherin (MTDH) provides survival advantage under conditions of stress by acting as RNA-binding protein.
Specimen part
View SamplesGene expression profiles were compared between L-428 HRS cells transduced with shRNA against AP-1 transcription factor BATF3 and L-428 HRS cells transduced with a non-targeting shRNA as control.
An oncogenic axis of STAT-mediated BATF3 upregulation causing MYC activity in classical Hodgkin lymphoma and anaplastic large cell lymphoma.
Specimen part
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