Project description:Previous epidemiological studies have shown that males tend to have an increased overall lifetime risk of developing atrial fibrillation (AF), whereas females tend to be more susceptible to the development of ventricular tachyarrhythmias resulting from long-QT syndrome and drug-induced Torsades de Pointes. In this study, we compared the transcript-level expression of 89 ion channel subunits, calcium handling proteins, and other transcription factors in the left atria (LA) and ventricles (LV) of human hearts of both genders.
Project description:<p>The goal of this study was to search for genetic variants that could be responsible for modifying the risk of drug-induced long QT syndrome (diLQTS). diLQTS is a relatively common adverse drug event and has been a leading cause for drug relabeling and withdrawal from the market. Our hypothesis, that variants in genes which regulate electrical properties in the heart modify the risk of diLQTS, was tested by sequencing approximately 225 patients of European descent using next-generation targeted captured or whole exome sequencing. Data from cases and controls (1:2) were analyzed to identify both rare and common genetic variation.</p>
Project description:<p>The goal of this study was to search for genetic variants that could be responsible for modifying the risk of drug-induced long QT syndrome (diLQTS). diLQTS is a relatively common adverse drug event and has been a leading cause for drug relabeling and withdrawal from the market. Our hypothesis, that variants in genes which regulate electrical properties in the heart modify the risk of diLQTS, was tested by genotyping patients of European descent at 1424 single nucleotide polymorphisms (SNPs) in 18 candidate genes. We found that the SNP KCNE1 D85N was highly predictive of diLQTS with an odds ratio of 9.0 (95% confidence interval: 3.5-22.9).</p>
Project description:Regulation of embryonic liver growth remains largely elusive. Progranulin has been discussed in pathological liver growth; however, the functional role of Pgrn in embryonic liver growth has never been addressed. Knockdown of GrnA, the orthologue of mammalian pgrn in zebrafish, displayed a deficient hepatic outgrowth during hepatogenesis. Expression profiles manifested that pgrn-deficiency impaired hepatogenesis associated with dysregulation of Met signaling. Pgrn regulates hepatic expression of Met was further verified in vitro and in vivo. These results indicate that Pgrn is a novel factor required for embryonic hepatic outgrowth and reveal a novel link between Pgrn and Met signaling. To explore the GrnA induced genomic responses during hepatic outgrowth, mRNA expression profiles were compared from grnA morphants and control embryos using zebrafish 14K oligonucleotide microarray at 72 hpf, when hepatocytes were rapid proliferating.
Project description:Previous epidemiological studies have shown that males tend to have an increased overall lifetime risk of developing atrial fibrillation (AF), whereas females tend to be more susceptible to the development of ventricular tachyarrhythmias resulting from long-QT syndrome and drug-induced Torsades de Pointes. In this study, we compared the transcript-level expression of 89 ion channel subunits, calcium handling proteins, and other transcription factors in the left atria (LA) and ventricles (LV) of human hearts of both genders. Total RNA from the LA and LV of failing male (n=9), failing female (n=7), nonfailing male (n=9), and nonfailing female (n=9) hearts was probed using a custom-designed Taqman gene array from Applied Biosystems. Tissues from LA (n=22), LV (n=22), LV endocardium (n=12), and LV epicardium (n=12) were analyzed by the Applied Biosystems SDS 2.3 software using the threshold cycle (Ct) relative quantification method with GAPDH as an endogenous control.
Project description:Engineered human cardiac tissues have been utilized for various biomedical applications, including drug testing, disease modeling, and regenerative medicine. However, the applications of cardiac tissues derived from human pluripotent stem cells are often limited due to their immaturity and lack of functionality. Therefore, in this study, we established a perfusable culture system based on in vivo-like heart microenvironments to improve human cardiac tissue fabrication. The integrated culture platform of a microfluidic chip and a three-dimensional heart extracellular matrix enhanced human cardiac tissue development and their structural and functional maturation. These tissues were comprised of cardiovascular lineage cells, including cardiomyocytes and cardiac fibroblasts derived from human induced pluripotent stem cells, as well as vascular endothelial cells. The resultant macroscale human cardiac tissues exhibited improved efficacy in drug testing (small molecules with various levels of arrhythmia risk), disease modeling (long QT syndrome and cardiac fibrosis), and regenerative therapy (myocardial infarction treatment). Therefore, our culture system can serve as a highly effective tissue-engineering platform to provide human cardiac tissues for versatile biomedical applications.
Project description:<p>The goal of this study was to identify genetic risk factors for drug-induced prolongation of the QT interval (diLQT) and the ventricular arrhythmia torsades de pointes (TdP). We conducted a genome-wide association study (GWAS) focusing on subjects with a history of long QT and/or TdP after taking medication. Controls for this study were individuals with a history of cardiac arrhythmias who had begun treatment with potentially QT-prolonging antiarrhythmics. An additional control group of normal volunteers were given ibutilide, a drug with documented proarrhythmic properties. All study participants were recruited and treated/evaluated at Vanderbilt University Medical Center.</p> <p>This study was conducted by the Pharmacogenomics of Arrhythmia Therapy subgroup of the Pharmacogenetics Research Network, a nationwide collaboration of scientists studying the genetic contributions to drug response variability. Genotyping was performed by the RIKEN research institute in Japan using the Illumina 610 Quad Beadchip platform.</p>