Insight into mechanisms controlling gene expression in the spermatogonial stem cell (SSC) will improve our understanding of the processes regulating spermatogenesis and aid in treating problems associated with male infertility.
Spermatogonial stem cell self-renewal requires ETV5-mediated downstream activation of Brachyury in mice.
Specimen part, Treatment
View SamplesMicroRNAs (miRs) play a key role in the control of gene expression in a wide array of tissue systems where their functions include the regulation of self-renewal, cellular differentiation, proliferation, and apoptosis. However, the functional importance of individual miRs in controlling spermatogonial stem cell (SSC) homeostasis has not been investigated. Using high-throughout sequencing, we profiled the expression of miRs in the Thy1+ testis cell population, which is highly enriched for SSCs, and the Thy1- cell population, composed primarily of testis somatic cells. In addition, we profiled the global expression of miRs in cultured germ cells, also enriched for SSCs. Our results demonstrate that miR-21, along with miR-34c, -182, -183, -146a, -465a-3p, -465b-3p, -465c-3p, and -465c-5p are preferentially expressed in the Thy1+ SSC-enriched population, as compared to Thy1- somatic cells, and we further observed that Thy1+ SSC-enriched testis cells and SSC-enriched cultured germ cells share remarkably similar miR expression profiles. Overall design: Spermatogonial Stem Cell enriched cell populations (freshly isolated and short-term cultured) and somatic cell populations were isolated from C57B/L6 mouse donors and subjected to small RNA isolation and sequencing.
MicroRNA-21 regulates the self-renewal of mouse spermatogonial stem cells.
Specimen part, Cell line, Subject
View SamplesSkeletal muscle is composed of both slow-twich oxidative myofibers and fast-twitch glycolytic myofibers that differentially impact muscle metabolism, function, and eventually whole-body physiology. In the present study, we find that the mesodermal transcription factor T-box 15 (Tbx15) is highly and specifically expressed in glycolytic myofibers. Ablation of Tbx15 in vivo leads to a decrease in muscle size due to a decrease in the number of glycolytic fibers, associated with a small increase in the number of oxidative fibers. This shift in fiber composition results in muscles with slower myofiber contraction and relaxation, and also results in decreased whole-body oxygen consumption, decreased spontaneous activity, increased adiposity, and glucose intolerance. In order to identify genes regulated by Tbx15, we utilized C2C12 myoblasts with either a stable retroviral over-expression or stable lentiviral knockdown of Tbx15.
Tbx15 controls skeletal muscle fibre-type determination and muscle metabolism.
Specimen part, Cell line, Treatment
View SamplesThe derivation of molecular signatures indicative of disease status and predictive of subsequent behavior could facilitate the optimal choice of treatment for prostate cancer patients. In this study, we conducted a computational analysis of gene expression profile data obtained from 79 cases, 39 of which were classified as having disease recurrence, to investigate whether advanced computational algorithms can derive more accurate prognostic signatures for prostate cancer. At the 90% sensitivity level, a newly derived prognostic genetic signature achieved 85% specificity. This is the first reported genetic signature to outperform a clinically used postoperative nomogram. Furthermore, a hybrid prognostic signature derived by combination of the nomogram and gene expression data significantly outperformed both genetic and clinical signatures, and achieved a specificity of 95%. Our study demonstrates the feasibility of utilizing gene expression information for highly accurate prostate cancer prognosis beyond the current clinical systems, and shows that more advanced computational modeling of tissue-derived microarray data is warranted before clinical application of molecular signatures is considered.
Optimizing molecular signatures for predicting prostate cancer recurrence.
Specimen part
View SamplesExercise training improves whole body glucose homeostasis through effects largely attributed to adaptations in skeletal muscle; however, training also affects other tissues including adipose tissue. To determine if exercise-induced adaptations to adipose tissue contribute to training-induced improvements in glucose homeostasis, subcutaneous white adipose tissue (scWAT) from trained or sedentary donor mice was transplanted into the visceral cavity of sedentary recipients. Remarkably, nine days post-transplantation, mice receiving trained scWAT had improved glucose tolerance and enhanced insulin sensitivity compared to mice transplanted with sedentary scWAT or sham-treated mice. Mice transplanted with trained scWAT had increased insulin-stimulated glucose uptake in tibialis anterior and soleus muscles and brown adipose tissue, suggesting that the transplanted scWAT exerted endocrine effects. Furthermore, the deleterious effects of high-fat feeding on glucose tolerance and insulin sensitivity were completely reversed if high-fat fed recipient mice were transplanted with trained scWAT. In additional experiments, voluntary exercise training by wheel running for only 11 days resulted in profound changes in scWAT including increased expression of 1550 genes involved in numerous cellular functions, including metabolism. Exercise training causes adaptations to scWAT that elicit metabolic improvements in other tissues, demonstrating a previously unrecognized role for adipose tissue in the beneficial effects of exercise on systemic glucose homeostasis.
A novel role for subcutaneous adipose tissue in exercise-induced improvements in glucose homeostasis.
Sex, Age, Specimen part
View SamplesIn this study we applied differential gene expression analysis to exfoliated human urothelia obtained from patients of known bladder disease status. Selected targets from the microarray data were validated in an independent set of samples using a quantitative PCR approach.
A candidate molecular biomarker panel for the detection of bladder cancer.
Specimen part, Disease
View SamplesWe recently identified the nonreceptor tyrosine kinase syk as a tumor suppressor in pancreatic ductal adenocarcinoma cells. Reintroduction of syk into Panc1 cells promoted a more differentiated phenotype and retarded invasion and tumorigenic growth. Gene array analysis identified over 2,000 transcripts differentially expressed at FDR<0.01. Among these were members of the MMP2 axis, which were subsequently shown to regulate Panc1 invasion.
Syk tyrosine kinase acts as a pancreatic adenocarcinoma tumor suppressor by regulating cellular growth and invasion.
Cell line
View SamplesMultipotent C3H10T1/2 cells can be induced to differentiate into mature brown adipocytes by 3-days BMP7 pretreatment followed by standard adipogenic induction.
MicroRNA-455 regulates brown adipogenesis via a novel HIF1an-AMPK-PGC1α signaling network.
Cell line
View SamplesBranched-chain amino acids (BCAA) have emerged as predictors of type 2 diabetes (T2D). However, their potential role in the pathogenesis of insulin resistance and T2D remains unclear. By integrating data from skeletal muscle gene expression and metabolomic analyses, we demonstrate evidence for perturbation in BCAA metabolism and fatty acid oxidation in skeletal muscle from insulin-resistant humans. Experimental modulation of BCAA flux in cultured cells alters fatty acid oxidation in parallel. Furthermore, heterozygosity for the BCAA metabolic enzyme methylmalonyl-CoA mutase (MUT) alters muscle lipid metabolism in vivo, resulting in increased muscle triacylglycerol (TAG) accumulation and increased body weight after high-fat feeding. Together, our results demonstrate that impaired muscle BCAA catabolism may contribute to the development of insulin resistance by reducing fatty acid oxidation and increasing TAG accumulation.
Defects in muscle branched-chain amino acid oxidation contribute to impaired lipid metabolism.
Sex, Age, Specimen part, Treatment
View SamplesIn this study, we investigated signaling pathways in Skeletal muscle precursors that are altered with aging and age-related deficits in muscle regenerative potential. We performed fluorescence activated cell sorting (FACS) to obtain highly purified skeletal muscle satellite cells from young, middle-aged and old mice.
Restoring systemic GDF11 levels reverses age-related dysfunction in mouse skeletal muscle.
Specimen part
View Samples