A pilot study on DNA methylation changes for non-invasive molecular diagnostics in heart failure.

Aims: The current therapeutic approach to ischaemic (IsHF) and non-ischaemic (NIsHF) heart failure (HF) mainly overlooks the underlying aetiology owing to a lack knowledge of the differential molecular pathways that contribute to HF with reduced ejection fraction (HFrEF). Alterations in myocardial DNA methylation levels have been identified as potential biomarkers for HF irrespective of its aetiology. Due to the limited availability of cardiac tissues in clinics, our goal is to determine if DNA methylation changes in circulating CD4 T lymphocytes, which are strongly involved in left ventricle remodelling, can help in differentiating IsHF and NIsHF causes among patients with HFrEF and if DNA methylation levels associate with key clinical features.

Mitochondrial NNT Promotes Diastolic Dysfunction in Cardiometabolic HFpEF.

Background: Clinical management of heart failure with preserved ejection fraction (HFpEF) is hindered by a lack of disease-modifying therapies capable of altering its distinct pathophysiology. Despite the widespread implementation of a 2-hit model of cardiometabolic HFpEF to inform precision therapy, which utilizes HFD+L-NAME (ad libitum high-fat diet and 0.5% N[ω]-nitro-L-arginine methyl ester), we observe that C57BL6/J mice exhibit less cardiac diastolic dysfunction in response to HFD+L-NAME.

Integrative analysis of single-cell transcriptomics and genetic associations identify cell states associated with vascular disease.

Background: Vascular diseases are accompanied by alterations in cellular phenotypes which underlie disease pathogenesis, with single-cell technologies aiding in the discovery of cellular heterogeneity among endothelial cell (EC) and vascular smooth muscle cell (VSMC) populations. In atherosclerotic disease, VSMCs are hypothesized to transition between contractile and synthetic states; however, the specific vascular subpopulations and intermediate cell states responsible for early vascular dysfunction remain unclear.

Methods: We integrated newly generated and published single-nuclear RNA-sequencing (snRNA-seq) datasets to analyze normal (n = 7), aneurysmal (n = 9), and atherosclerotic (n = 2) flash-frozen human ascending thoracic aortas.

DNA hypermethylation of MED1 and MED23 as early diagnostic biomarkers for unsolved issues in atrial fibrillation.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. Much effort was spent to identify biomarkers useful to stratify AF patients. Mediator complex (MED) is an ancestral regulator of transcriptional mechanisms.

High-resolution DNA methylation changes reveal biomarkers of heart failure with preserved ejection fraction versus reduced ejection fraction.

Novel biomarkers are needed to better identify-and distinguish-heart failure with preserved ejection fraction (HFpEF) from other clinical phenotypes. The goal of our study was to identify epigenetic-sensitive biomarkers useful to a more accurate diagnosis of HFpEF. We performed a network-oriented genome-wide DNA methylation study of circulating CD4 T lymphocytes isolated from peripheral blood using reduced representation bisulfite sequencing (RRBS) in two cohorts (i.

CDK5R1, GSE1, HSPG2 and WDFY3 as indirect epigenetic-sensitive genes in atrial fibrillation.

Background: Although mounting evidence supports that aberrant DNA methylation occurs in the hearts of patients with atrial fibrillation (AF), noninvasive epigenetic characterization of AF has not yet been defined.

Methods: We investigated DNA methylome changes in peripheral blood CD4 T cells isolated from 10 patients with AF relative to 11 healthy subjects (HS) who were enrolled in the DIANA clinical trial (NCT04371809) via reduced-representation bisulfite sequencing (RRBS).

Results: An atrial-specific PPI network revealed 18 hub differentially methylated genes (DMGs), wherein ROC curve analysis revealed reasonable diagnostic performance of DNA methylation levels found within CDK5R1 (AUC = 0.

The Role of Endothelial Cells in Atherosclerosis: Insights from Genetic Association Studies.

Endothelial cells (ECs) mediate several biological functions that are relevant to atherosclerosis and coronary artery disease (CAD), regulating an array of vital processes including vascular tone, wound healing, reactive oxygen species, shear stress response, and inflammation. Although which of these functions is linked causally with CAD development and/or progression is not yet known, genome-wide association studies have implicated more than 400 loci associated with CAD risk, among which several have shown EC-relevant functions. Given the arduous process of mechanistically interrogating single loci to CAD, high-throughput variant characterization methods, including pooled Clustered Regularly Interspaced Short Palindromic Repeats screens, offer exciting potential to rapidly accelerate the discovery of bona fide EC-relevant genetic loci.

Indirect epigenetic testing identifies a diagnostic signature of cardiomyocyte DNA methylation in heart failure.

Precision-based molecular phenotyping of heart failure must overcome limited access to cardiac tissue. Although epigenetic alterations have been found to underlie pathological cardiac gene dysregulation, the clinical utility of myocardial epigenomics remains narrow owing to limited clinical access to tissue. Therefore, the current study determined whether patient plasma confers indirect phenotypic, transcriptional, and/or epigenetic alterations to ex vivo cardiomyocytes to mirror the failing human myocardium.

Deep phenotyping of two preclinical mouse models and a cohort of RBM20 mutation carriers reveals no sex-dependent disease severity in cardiomyopathy.

cardiomyopathy is an arrhythmogenic form of dilated cardiomyopathy caused by mutations in the splicing factor RBM20. A recent study found a more severe phenotype in male patients with cardiomyopathy patients than in female patients. Here, we aim to determine sex differences in an animal model of cardiomyopathy and investigate potential underlying mechanisms.

A novel curricular framework to develop grant writing skills among MD-PhD students.

Background/objectives: Physician-scientists have long been in high demand owing to their role as key drivers of biomedical innovation, but their dwindling prevalence in research and medical communities threatens ongoing progress. As the principal avenue for physician-scientist development, combined MD-PhD training programs and NIH-funded Medical Scientist Training Programs (MSTPs) must address all aspects of career development, including grant writing skills.

Methods: The NIH F-series grants - the F30 grant in particular - model the NIH format of federal funding, and are thus ideal opportunities to acquire biomedical research grant preparation experience.

Fostering a diverse regional community of physician-scientist trainees.

Among the many academic challenges faced by dual-degree MD-PhD students is access to professional support networks designed to overcome the unique academic and personal barriers to physician-scientist training. In the current study, we hypothesized that regional access to a student MD-PhD conference, termed the Southeastern Medical Scientist Symposium (SEMSS), would enhance medical and/or graduate training by fostering such relationships between physician-scientist trainees, doing so by discussing both the challenges of physician-scientist training and effective strategies to overcome them. In the current study, we used a mixed-methods approach to evaluate the overall usefulness of SEMSS over a ten-year period (2010-2020) to identify key areas of particular benefit to trainees.

Identification of Nrf2-responsive microRNA networks as putative mediators of myocardial reductive stress.

Although recent advances in the treatment of acute coronary heart disease have reduced mortality rates, few therapeutic strategies exist to mitigate the progressive loss of cardiac function that manifests as heart failure. Nuclear factor, erythroid 2 like 2 (Nfe2l2, Nrf2) is a transcriptional regulator that is known to confer transient myocardial cytoprotection following acute ischemic insult; however, its sustained activation paradoxically causes a reductive environment characterized by excessive antioxidant activity. We previously identified a subset of 16 microRNAs (miRNA) significantly diminished in Nrf2-ablated (Nrf2) mouse hearts, leading to the hypothesis that increasing levels of Nrf2 activation augments miRNA induction and post-transcriptional dysregulation.

The human aortic endothelium undergoes dose-dependent DNA methylation in response to transient hyperglycemia.

Background: Glycemic control is a strong predictor of long-term cardiovascular risk in patients with diabetes mellitus, and poor glycemic control influences long-term risk of cardiovascular disease even decades after optimal medical management. This phenomenon, termed glycemic memory, has been proposed to occur due to stable programs of cardiac and endothelial cell gene expression. This transcriptional remodeling has been shown to occur in the vascular endothelium through a yet undefined mechanism of cellular reprogramming.

Increased Glucose Availability Attenuates Myocardial Ketone Body Utilization.

Background Perturbations in myocardial substrate utilization have been proposed to contribute to the pathogenesis of cardiac dysfunction in diabetic subjects. The failing heart in nondiabetics tends to decrease reliance on fatty acid and glucose oxidation, and increases reliance on ketone body oxidation. In contrast, little is known regarding the mechanisms mediating this shift among all 3 substrates in diabetes mellitus.

Maintaining Myocardial Glucose Utilization in Diabetic Cardiomyopathy Accelerates Mitochondrial Dysfunction.

Cardiac glucose uptake and oxidation are reduced in diabetes despite hyperglycemia. Mitochondrial dysfunction contributes to heart failure in diabetes. It is unclear whether these changes are adaptive or maladaptive.

Differential DNA Methylation Encodes Proliferation and Senescence Programs in Human Adipose-Derived Mesenchymal Stem Cells.

Adult adipose tissue-derived mesenchymal stem cells (ASCs) constitute a vital population of multipotent cells capable of differentiating into numerous end-organ phenotypes. However, scientific and translational endeavors to harness the regenerative potential of ASCs are currently limited by an incomplete understanding of the mechanisms that determine cell-lineage commitment and stemness. In the current study, we used reduced representation bisulfite sequencing (RRBS) analysis to identify epigenetic gene targets and cellular processes that are responsive to 5'-azacitidine (5'-AZA).

Gamification: An Innovative Approach to Reinforce Clinical Knowledge for MD-PhD Students During Their PhD Research Years.

A longstanding challenge facing MD-PhD students and other dual-degree medical trainees is the loss of clinical knowledge that occurs during the non medical phases of training. Academic medical institutions nationwide have developed continued clinical training and exposure to maintain clinical competence; however, quantitative assessment of their usefulness remains largely unexplored. The current study therefore sought to both implement and optimize an online game platform to support MD-PhD students throughout their research training.

Dysregulation of the Mitochondrial Proteome Occurs in Mice Lacking Adiponectin Receptor 1.

Decreased serum adiponectin levels in type 2 diabetes has been linked to the onset of mitochondrial dysfunction in diabetic complications by impairing AMPK-SIRT1-PGC-1α signaling via impaired adiponectin receptor 1 (AdipoR1) signaling. Here, we aimed to characterize the previously undefined role of disrupted AdipoR1 signaling on the mitochondrial protein composition of cardiac, renal, and hepatic tissues as three organs principally associated with diabetic complications. Comparative proteomics were performed in mitochondria isolated from the heart, kidneys and liver of mice.

The SETD6 Methyltransferase Plays an Essential Role in Hippocampus-Dependent Memory Formation.

Background: Epigenetic mechanisms are critical for hippocampus-dependent memory formation. Building on previous studies that implicate the N-lysine methyltransferase SETD6 in the activation of nuclear factor-κB RELA (also known as transcription factor p65) as an epigenetic recruiter, we hypothesized that SETD6 is a key player in the epigenetic control of long-term memory.

Methods: Using a series of molecular, biochemical, imaging, electrophysiological, and behavioral experiments, we interrogated the effects of short interfering RNA-mediated knockdown of Setd6 in the rat dorsal hippocampus during memory consolidation.

DNA methylation reprograms cardiac metabolic gene expression in end-stage human heart failure.

Heart failure (HF) is a leading cause of morbidity and mortality in the United States and worldwide. As a multifactorial syndrome with unpredictable clinical outcomes, identifying the common molecular underpinnings that drive HF pathogenesis remains a major focus of investigation. Disruption of cardiac gene expression has been shown to mediate a common final cascade of pathological hallmarks wherein the heart reactivates numerous developmental pathways.

Prolactin Receptor Signaling Regulates a Pregnancy-Specific Transcriptional Program in Mouse Islets.

Pancreatic β-cells undergo profound hyperplasia during pregnancy to maintain maternal euglycemia. Failure to reprogram β-cells into a more replicative state has been found to underlie susceptibility to gestational diabetes mellitus (GDM). We recently identified a requirement for prolactin receptor (PRLR) signaling in the metabolic adaptations to pregnancy, where β-cell-specific PRLR knockout (βPRLRKO) mice exhibit a metabolic phenotype consistent with GDM.

Resident macrophages reprogram toward a developmental state after acute kidney injury.

Acute kidney injury (AKI) is a devastating clinical condition affecting at least two-thirds of critically ill patients, and, among these patients, it is associated with a greater than 60% risk of mortality. Kidney mononuclear phagocytes (MPs) are implicated in pathogenesis and healing in mouse models of AKI and, thus, have been the subject of investigation as potential targets for clinical intervention. We have determined that, after injury, F4/80hi-expressing kidney-resident macrophages (KRMs) are a distinct cellular subpopulation that does not differentiate from nonresident infiltrating MPs.