Skeletal muscle mitochondrial dysfunction is secondary to T2DM and can be improved by long-term regular exercise training
Physical activity is the key determinant of skeletal muscle mitochondrial function in type 2 diabetes.
Age
View SamplesThe insulin-like growth factor (IGF) system consists of two ligands (IGF-I and IGF-II), which both signal through type I IGF receptor (IGF-IR) to stimulate proliferation and inhibit apoptosis, with activity contributing to malignant growth of many types of human cancers. We have developed a humanized, affinity-matured anti-human IGF-IR monoclonal antibody (h10H5), which binds with high affinity and specificity to the extracellular domain. h10H5 inhibits IGF-IR-mediated signaling by blocking IGF-I and IGF-IIbinding and by inducing cell surface receptor down-regulation via internalization and degradation. In vitro, h10H5 exhibits anti-proliferative effects on cancer cell lines. In vivo, h10H5 demonstrates single-agent anti-tumor efficacy in human SK-N-AS neuroblastoma and SW527 breast cancer xenograft models, and even greater efficacy in combination with the chemotherapeutic agent Docetaxel or an anti-VEGF antibody. Anti-tumor activity of h10H5 is associated with decreased AKT activation and glucose uptake, and a 316-gene transcription profile with significant changes involving DNA metabolic and cell cycle machineries. These data support the clinical testing of h10H5 as a biotherapeutic for IGF-IR-dependent human tumors.
Antixenograft tumor activity of a humanized anti-insulin-like growth factor-I receptor monoclonal antibody is associated with decreased AKT activation and glucose uptake.
No sample metadata fields
View SamplesThe LIM-only protein FHL2 is expressed in SMCs and inhibits SMC-rich lesion formation. However, the underlying mechanism behind FHL2's action in SMCs has been only partially resolved. To further elucidate the role of FHL2 in SMCs we compared the transcriptome of cultured SMCs derived from wild-type (WT) and FHL2-knockout (KO) mice.
LIM-only protein FHL2 is a positive regulator of liver X receptors in smooth muscle cells involved in lipid homeostasis.
Specimen part
View SamplesThe skeletal muscle system plays an important role in the independence of older adults. In this study we examine differences in the skeletal muscle transcriptome between healthy young and older subjects and (pre)frail older adults. Additionally, we examine the effect of resistancetype exercise training on the muscle transcriptome in healthy older subjects and (pre)frail older adults. Baseline transcriptome profiles were measured in muscle biopsies collected from 53 young, 73 healthy older subjects, and 61 frail older subjects. Followup samples from these frail older subjects (31 samples) and healthy older subjects (41 samples) were collected after 6 months of progressive resistancetype exercise training. Frail older subjects trained twice per week and the healthy older subjects trained three times per week. At baseline genes related to mitochondrial function and energy metabolism were differentially expressed between older and young subjects, as well as between healthy and frail older subjects. Three hundred seven genes were differentially expressed after training in both groups. Training affected expression levels of genes related to extracellular matrix, glucose metabolism, and vascularization. Expression of genes that were modulated by exercise training was indicative of muscle strength at baseline. Genes that strongly correlated with strength belonged to the protocadherin gamma gene cluster (r=0.73). Our data suggest significant remaining plasticity of ageing skeletal muscle to adapt to resistancetype exercise training. Some agerelated changes in skeletal muscle gene expression appear to be partially reversed by prolonged resistancetype exercise training. The protocadherin gamma gene cluster may be related to muscle denervation and reinnervation in ageing muscle.
Expression of protocadherin gamma in skeletal muscle tissue is associated with age and muscle weakness.
Sex, Specimen part, Subject
View SamplesExpression analysis of migrating and non-migrating mesenchymal stromal cells (MSC) in fetal bone marrow
Nuclear receptors Nur77 and Nurr1 modulate mesenchymal stromal cell migration.
Specimen part
View SamplesMedium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) catalyzes crucial steps in mitochondrial fatty acid oxidation, a process that is of key relevance for maintenance of energy homeostasis, especially during high metabolic demand. To gain insight into the metabolic consequences of MCAD deficiency under these conditions, we compared hepatic carbohydrate metabolism in vivo in wild-type and MCAD-/- mice during fasting and during a lipopolysaccharide (LPS)-induced acute phase response (APR). MCAD-/- mice did not become more hypoglycemic on fasting or during the APR than wild-type mice did. Nevertheless, microarray analyses revealed increased hepatic peroxisome proliferator-activated receptor gamma coactivator-1a (Pgc-1a) and decreased peroxisome proliferator-activated receptor alpha (Ppar a) and pyruvate dehydrogenase kinase 4 (Pdk4) expression in MCAD-/- mice in both conditions,suggesting altered control of hepatic glucose metabolism. Quantitative flux measurements revealed that the de novo synthesis of glucose-6-phosphate (G6P) was not affected on fasting in MCAD-/- mice. During the APR, however, this flux was significantly decreased (-20%) in MCAD-/- mice compared with wild-type mice. Remarkably, newly formed G6P was preferentially directed toward glycogen in MCAD-/- mice under both conditions. Together with diminished de novo synthesis of G6P, this led to a decreased hepatic glucose output during the APR in MCAD-/- mice; de novo synthesis of G6P and hepatic glucose output were maintained in wild-type mice under both conditions. APR-associated hypoglycemia, which was observed in wild-type mice as well as MCAD-/- mice, was mainly due to enhanced peripheral glucose uptake. Conclusion: Our data demonstrate that MCAD deficiency in mice leads to specific changes in hepatic carbohydrate management on exposure to metabolic stress. This deficiency, however, does not lead to reduced de novo synthesis of G6P during fasting alone, which may be due to the existence of compensatory mechanisms or limited rate control of MCAD in murine mitochondrial fatty acid oxidation.
Disturbed hepatic carbohydrate management during high metabolic demand in medium-chain acyl-CoA dehydrogenase (MCAD)-deficient mice.
Sex, Specimen part, Treatment
View SamplesThe HMG-box factor Tcf1 is required during T-cell development in the thymus and mediates the nuclear response to Wnt signals. Tcf1/ mice have previously been characterized and show developmental blocks at the CD4CD8 double negative (DN) to CD4+CD8+ double positive transition. Due to the blocks in T-cell development, Tcf1/ mice normally have a very small thymus. Unexpectedly, a large proportion of Tcf1/ mice spontaneously develop thymic lymphomas with 50% of mice developing a thymic lymphoma/leukemia at the age of 16 wk. These lymphomas are clonal, highly metastatic, and paradoxically show high Wnt signaling when crossed with Wnt reporter mice and have high expression of Wnt target genes Lef1 and Axin2. In wild-type thymocytes, Tcf1 is higher expressed than Lef1, with a predominance of Wnt inhibitory isoforms. Loss of Tcf1 as repressor of Lef1 leads to high Wnt activity and is the initiating event in lymphoma development, which is exacerbated by activating Notch1 mutations. Thus, Notch1 and loss of Tcf1 functionally act as collaborating oncogenic events. Tcf1 deficiency predisposes to the development of thymic lymphomas by ectopic up-regulation of Lef1 due to lack of Tcf1 repressive isoforms and frequently by cooperating activating mutations in Notch1. Tcf1 therefore functions as a T-cellspecific tumor suppressor gene, besides its established role as a Wnt responsive transcription factor. Thus, Tcf1 acts as a molecular switch between proliferative and repressive signals during T-lymphocyte development in the thymus.
The nuclear effector of Wnt-signaling, Tcf1, functions as a T-cell-specific tumor suppressor for development of lymphomas.
Specimen part
View SamplesIntroduction: Mammalian target of rapamycin (mTOR) represents a key downstream intermediate for a myriad of oncogenic receptor tyrosine kinases. In the case of the insulin-like growth factor (IGF) pathway, the mTOR complex (mTORC1) mediates IGF-1 receptor (IGF-1R)-induced estrogen receptor alpha (ERa) phosphorylation/activation and leads to increased proliferation and growth in breast cancer cells. As a result, the prevalence of mTOR inhibitors combined with hormonal therapy has increased in recent years. Conversely, activated mTORC1 provides negative feedback regulation of IGF signaling via insulin receptor substrate (IRS)-1/2 serine phosphorylation and subsequent proteasomal degradation. Thus, the IGF pathway may provide escape (e.g. de novo or acquired resistance) from mTORC1 inhibitors. It is therefore plausible that combined inhibition of mTORC1 and IGF-1R for select subsets of ER-positive breast cancer patients presents as a viable therapeutic option. Methods: Using hormone-sensitive breast cancer cells stably transfected with the aromatase gene (MCF-7/AC-1), works presented herein describe the in vitro and in vivo antitumor efficacy of the following compounds: dalotuzumab (DALO; “MK-0646”; anti-IGF-1R antibody), ridaforolimus (RIDA; “MK-8669”; mTORC1 small molecule inhibitor) and letrozole (“LET”, aromatase inhibitor). Results: With the exception of MK-0646, all single agent and combination treatment arms effectively inhibited xenograft tumor growth, albeit to varying degrees. Correlative tissue analyses revealed MK-0646 alone and in combination with LET induced insulin receptor alpha A (InsR-A) isoform upregulation (both mRNA and protein expression), thereby further supporting a triple therapy approach. Conclusion: These data provide preclinical rationalization towards the combined triple therapy of LET plus MK-0646 plus MK-8669 as an efficacious anti-tumor strategy for ER-positive breast tumors. Overall design: 46 samples, 28 days post treatment
Ridaforolimus (MK-8669) synergizes with Dalotuzumab (MK-0646) in hormone-sensitive breast cancer.
Cell line, Treatment, Subject, Time
View SampleslncRNAs not only participate in normal hematopoiesis but also contribute to the pathogenesis of acute leukemia. However, their clinical and prognostic relevance in MDS remains unclear to date.
A 4-lncRNA scoring system for prognostication of adult myelodysplastic syndromes.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesHeart failure remains a major unmet clinical need and current therapies targeting neurohomonal and hemodynamic regulation have limited efficacy. We report that pharmacological activation of the transcriptional repressor REV-ERBa prevents expression of a pathological gene program and cardiomyocyte hypertrophy. In vivo, REV-ERBa agonism prevents development and halts progression of heart failure in mouse models. Thus, modulation of gene networks by targeting REV-ERBa represents a novel approach to heart failure therapy. Overall design: We performed RNAseq on NRVM at baseline and after PE stimulation (4 hr and 48 hr) in the presence or absence of SR9009 (SR or Veh were given 24 hr prior to PE).
REV-ERBα ameliorates heart failure through transcription repression.
No sample metadata fields
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