Several different mechanical signals have been proposed to control the extent and pattern of myocardial growth and remodeling, though this has largely been studied using in vitro model systems that are not representative of intact myocardium or in vivo models in which isolating the effects of individual candidate stimuli is exceedigly difficult. We used a unique tissue culture system that allows the simultaneous control of multiple mechanical inputs and other potentially confounding stimuli (e.g., hormonal).
Effects of stretch and shortening on gene expression in intact myocardium.
Sex, Age
View SamplesExpression data from antigen-experienced Nfat1+/+ and Nfat1-/- CD4+ T cells following 21 days of Plasmodium yoelii 17XNL infection.
The Transcription Factor NFAT1 Participates in the Induction of CD4<sup>+</sup> T Cell Functional Exhaustion during Plasmodium yoelii Infection.
Sex, Specimen part
View SamplesMicroRNAs (miRNAs) regulate many basic aspects of cell biology including neuronal plasticity, but little is known of their roles in drug addiction. Extended access to cocaine can trigger the emergence of compulsive drug-seeking behaviors, but molecular mechanisms regulating this process remain unclear. Here we report that microRNA-212 (miR-212) is upregulated in the dorsal striatum of rats with extended access to cocaine. Striatal overexpression of miR-212 decreases, whereas its inhibition increases cocaine intake in rats with extended but not restricted drug access, suggesting that miR-212 serves as a protective factor against the development of compulsive drug seeking. The transcription factor CREB (cAMP response element-binding protein) is considered a core regulator of cocaine reward. We show that miR-212 controls responsiveness to cocaine by dramatically amplifying striatal CREB signaling. This action occurs through miR-212-enhanced Raf-1 activity, resulting in adenylyl cyclase sensitization and increased expression of the essential CREB co-activator TORC (Transducer of Regulated CREB; also known as CRTC). Our findings suggest that striatal miR-212 signaling plays a key role in vulnerability to addiction, and that noncoding RNAs such as the miRNAs may serve as novel targets for the development of anti-addiction therapeutics.
Striatal microRNA controls cocaine intake through CREB signalling.
Sex, Specimen part, Cell line
View SamplesThis study characterizes the response of primary human endothelial cells (human umbilical vein endothelial cells, HUVECs) to the relative shear stress changes that occur during the initiation of arteriogenesis at the entrance regions to a collateral artery network. HUVECs were preconditioned to a baseline level of unidirectional shear of 15 dynes/cm2 for 24 hours. After 24 hours preconditioning, HUVECs were subjected to an arteriogenic stimulus that mimics the shear stress changes observed in the opposing entrance regions into a collateral artery network. The arteriogenic stimulus consisted of a 100% step wise increase in shear stress magnitude to a unidirectional 30 dynes/cm2 in either the same or opposite direction of the preconditioned shear stress. This simulates either the feeding entrance to the collateral artery circuit or the region that drains into the vasculature downstream of an obstruction in a major artery, respectively. In vivo analysis of collateral growth in the mouse hindlimb showed enhanced outward remodeling in the re-entrant (direction reversing) region that reconnects to the downstream arterial tree, suggesting reversal of shear stress direction as a key enhancer of arteriogenesis. Transcriptional profiling using microarray techniques identified that the reversal of shear stress direction, but not an increase in shear stress alone, yielded a broad-based enhancement of the mechanotransduction pathways necessary for the induction of arteriogenesis.
Mechanisms of Amplified Arteriogenesis in Collateral Artery Segments Exposed to Reversed Flow Direction.
Specimen part
View SamplesAims: Resident cardiac progenitor cells show homing properties when injected into the injured but not into the healthy myocardium. The molecular background behind this difference in behavior needs to be studied to elucidate how adult progenitor cells can restore cardiac function of the damaged myocardium. Since the brain-derived neurotrophic factor (BDNF) moderates cardioprotection in injured hearts, we focused on delineating its regulatory role in the damaged myocardium.
Brain derived neurotrophic factor contributes to the cardiogenic potential of adult resident progenitor cells in failing murine heart.
Age, Specimen part, Disease, Disease stage
View SamplesUnderstanding the contribution of abnormal genetic and epigenetic programs to acute myeloid leukemia (AML) is necessary for the integrated design of targeted therapies. To investigate this, we determined the effect of epigenetic reprogramming on leukemic behavior by generating induced pluripotent stem cells (iPSCs) from AML patient samples harboring MLL rearrangements. AML-derived iPSCs (AML-iPSCs) retained leukemic mutations, but reset leukemic DNA methylation/gene expression patterns and lacked leukemic potential. However, when differentiated into hematopoietic cells, AML-iPSCs reacquired the ability to give rise to leukemia in vivo and reestablished leukemic methylation/gene expression patterns, including an aberrant MLL signature, indicating that epigenetic reprogramming was insufficient to eliminate leukemic behavior. In one case, we identified distinct AML-iPSC KRAS mutant and wildtype subclones that demonstrated differential growth properties and therapeutic susceptibilities, predicting KRAS wildtype clonal relapse due to increased cytarabine resistance. Increased cytarabine resistance was further observed in a cohort of KRAS wildtype MLL-rearranged AML samples, demonstrating the utility of AML-iPSCs in predicting subclonal relapse and facilitating clonal targeting in AML. Overall design: RNA seq profiling of normal and leukemic differentiated and iPSC populations
Human AML-iPSCs Reacquire Leukemic Properties after Differentiation and Model Clonal Variation of Disease.
Specimen part, Subject
View SamplesThe goal of this study is to compare transcriptome profiling (RNA-seq) in controls, unaffected BMPR2 mutation carriers and affected familial pulmonary arterial hypertension patients, to elucidate a protective feature in iPS derived endothelial cells from the mutation carriers. Overall design: mRNA profiles of iPSC-ECs from unrelated control (n=3), unaffected BMPR2 mutation carriers (n=3) and FPAH patients with BMPR2 mutation (n=5).
Patient-Specific iPSC-Derived Endothelial Cells Uncover Pathways that Protect against Pulmonary Hypertension in BMPR2 Mutation Carriers.
Specimen part, Subject
View SamplesInflammatory hepatocellular adenomas (IHCA) are benign liver tumours defined by the presence of inflammatory infiltrates and by the elevated expression of inflammatory proteins in tumour hepatocytes1,2. Here we show a striking activation of the IL6 signalling pathway in this tumour type, and sequencing candidate genes pinpointed this response to somatic gain-of-function mutations in the IL6ST gene that encodes the signalling co-receptor gp130. Indeed, ~70% of IHCA harbour small in-frame deletions that target the binding site of gp130 for IL6, and expression of the most frequent gp130 mutant, Delta-STVY190, in hepatocellular cells activates STAT3 in absence of ligand. Further, analysis of hepatocellular carcinomas revealed rare gp130 alterations always accompanied by -catenin-activating mutations, suggesting a cooperative effect of these signalling pathways in the malignant conversion of hepatocytes. The recurrent gain-of-function gp130 mutations in these human hepatocellular adenomas explains their inflammatory phenotype, and suggest that similar alterations may occur in other inflammatory epithelial tumours with STAT3 activation.
Frequent in-frame somatic deletions activate gp130 in inflammatory hepatocellular tumours.
Sex, Specimen part, Disease
View SamplesThe character of the earliest cardiac precursor cells remains largely unknown. To elucidate this further, we constructed single cell cDNAs from the mouse embryonic cardiac precurcsor cells of the early allantoic bud stage and the early headfold stage, and subjected them to deep sequencing. Overall design: The most anterior part of the embryos where cardiac precursor cells exist was digested by trypsin to separate into single cells. After a cell was transferred into a reaction tube, single cell cDNAs were constructed as PCR amplicons. cDNAs of cardiac precursor cells were identified by PCR of marker genes.
Single-Cell Expression Profiling Reveals a Dynamic State of Cardiac Precursor Cells in the Early Mouse Embryo.
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View SamplesBackground: Immunoadsorption with subsequent IgG substitution (IA/IgG) represents a novel therapeutic approach in treatment of dilated cardiomyopathy (DCM) which leads to improvement of left ventricular ejection fraction (LVEF). However, response to this therapeutic intervention shows wide inter-individual variability. In this pilot study, we tested the value of clinical, biochemical and molecular parameters for prediction of the response of patients with DCM to IA/IgG.
Myocardial gene expression profiles and cardiodepressant autoantibodies predict response of patients with dilated cardiomyopathy to immunoadsorption therapy.
Sex, Age, Disease
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