scholarly journals Altered Cardiac Energetics and Mitochondrial Dysfunctionin Hypertrophic Cardiomyopathy

Circulation ◽  
2021 ◽  
Author(s):  
Sara Ranjbarvaziri ◽  
Kristina B. Kooiker ◽  
Mathew Ellenberger ◽  
Giovanni Fajardo ◽  
Mingming Zhao ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Drug Targets ◽  
Complex Disease ◽  
Citrate Synthase ◽  
High Energy ◽  
Antioxidant Defenses ◽  
Cardiac Energetics ◽  
Mitochondrial Injury ◽  
Individual Gene ◽  
Functional Components

Background: Hypertrophic cardiomyopathy (HCM) is a complex disease partly explained by the effects of individual gene variants on sarcomeric protein biomechanics. At the cellular level, HCM mutations most commonly enhance force production, leading to higher energy demands. Despite significant advances in elucidating sarcomeric structure-function relationships, there is still much to be learned about the mechanisms that link altered cardiac energetics to HCM phenotypes. In this work, we test the hypothesis that changes in cardiac energetics represent a common pathophysiologic pathway in HCM. Methods: We performed a comprehensive multi-omics profile of the molecular (transcripts, metabolites, and complex lipids), ultrastructural, and functional components of HCM energetics using myocardial samples from 27 HCM patients and 13 normal controls (donor hearts). Results: Integrated omics analysis revealed alterations in a wide array of biochemical pathways with major dysregulation in fatty acid metabolism, reduction of acylcarnitines, and accumulation of free fatty acids. HCM hearts showed evidence of global energetic decompensation manifested by a decrease in high energy phosphate metabolites [ATP, ADP, and phosphocreatine (PCr)] and a reduction in mitochondrial genes involved in creatine kinase and ATP synthesis. Accompanying these metabolic derangements, electron microscopy showed an increased fraction of severely damaged mitochondria with reduced cristae density, coinciding with reduced citrate synthase (CS) activity and mitochondrial oxidative respiration. These mitochondrial abnormalities were associated with elevated reactive oxygen species (ROS) and reduced antioxidant defenses. However, despite significant mitochondrial injury, HCM hearts failed to upregulate mitophagic clearance. Conclusions: Overall, our findings suggest that perturbed metabolic signaling and mitochondrial dysfunction are common pathogenic mechanisms in patients with HCM. These results highlight potential new drug targets for attenuation of the clinical disease through improving metabolic function and reducing mitochondrial injury.

Abstract 235: Hypertrophic Cardiomyopathy, a Disease of Altered Cardiac Energetics

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Sara Ranjbarvaziri ◽  
Mathew Ellenberger ◽  
Kristi Kooiker ◽  
Giovanni Fajardo ◽  
Mingming Zhao ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Drug Targets ◽  
Complex Disease ◽  
Citrate Synthase ◽  
Age Of Onset ◽  
High Energy ◽  
Antioxidant Defenses ◽  
Cardiac Energetics ◽  
Septal Myectomy ◽  
Functional Features

Hypertrophic cardiomyopathy (HCM) is a complex disease, the phenotypes of which are only partly explained by the biomechanical effects of individual genetic variants. At the cellular level, HCM sarcomeric mutations generally enhance maximal force production ultimately leading to higher energy demands. Despite significant advances in elucidating sarcomeric structure-function relationships, there is limited knowledge on the link between altered cardiac energetics and HCM phenotypes. In this work, we test the hypothesis that changes in cardiac energetics are a common pathway leading to the clinical pathophysiological phenotypes of HCM. We performed a comprehensive multi-omic study of the molecular, ultrastructural, and functional features of HCM energetics using septal myectomy samples from 27 HCM patients and 13 normal controls (donor hearts). Combined mass spectrometry and RNA-Seq revealed dramatic alterations in multiple metabolic pathways,with major dysregulation in fatty acid metabolism leading to reduced acylcarnitines and accumulation of free fatty acids. Additionally, HCM hearts showed clear signs of global energetic decompensation manifested by a decrease in high energy phosphate metabolites (ATP, ADP, and PCr) and reduction in several mitochondrial genes involved in creatine kinase and ATP synthesis machinery. Quantitative electron microscopy showed a marked increase in severely damaged mitochondria with reduced cristae density, affecting 10-12% of total mitochondria, coinciding with reduced citrate synthase (CS) activity and mitochondrial respiration. These mitochondrial abnormalities were associated with elevated ROS and reduced antioxidant defenses along with insufficient mitophagic clearance. Overall, our findings suggest that perturbed metabolic signaling and mitochondrial dysfunction are common pathogenic mechanisms in HCM. A central role for compromised energetics in HCM could also help explain the delayed age of onset of the clinical phenotype and present novel drug targets for attenuation of the clinical disease through reducing mitochondrial injury and improving function.

Genetic and Epigenetic Modulation of Drug Resistance in Cancer: Challenges and Opportunities

2020 ◽  
Vol 20 (14) ◽  
pp. 1114-1131 ◽  
Author(s):  
Kanisha Shah ◽  
Rakesh M. Rawal
Keyword(s):  
Drug Resistance ◽  
Drug Targets ◽  
Complex Disease ◽  
Cancer Therapies ◽  
Altered Expression ◽  
Acquired Drug Resistance ◽  
Challenges And Opportunities ◽  
Chemotherapeutic Treatment ◽  
Epigenetic Modulation ◽  
Targeted Drug Therapies

Cancer is a complex disease that has the ability to develop resistance to traditional therapies. The current chemotherapeutic treatment has become increasingly sophisticated, yet it is not 100% effective against disseminated tumours. Anticancer drugs resistance is an intricate process that ascends from modifications in the drug targets suggesting the need for better targeted therapies in the therapeutic arsenal. Advances in the modern techniques such as DNA microarray, proteomics along with the development of newer targeted drug therapies might provide better strategies to overcome drug resistance. This drug resistance in tumours can be attributed to an individual’s genetic differences, especially in tumoral somatic cells but acquired drug resistance is due to different mechanisms, such as cell death inhibition (apoptosis suppression) altered expression of drug transporters, alteration in drug metabolism epigenetic and drug targets, enhancing DNA repair and gene amplification. This review also focusses on the epigenetic modifications and microRNAs, which induce drug resistance and contributes to the formation of tumour progenitor cells that are not destroyed by conventional cancer therapies. Lastly, this review highlights different means to prevent the formation of drug resistant tumours and provides future directions for better treatment of these resistant tumours.

scholarly journals Twelve years of GWAS discoveries for osteoporosis and related traits: advances, challenges and applications

Bone Research ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaowei Zhu ◽  
Weiyang Bai ◽  
Houfeng Zheng
Keyword(s):  
Drug Targets ◽  
Complex Disease ◽  
Association Studies ◽  
Osteoporotic Fractures ◽  
Disease Prediction ◽  
Genome Wide Association Studies ◽  
Mineral Density ◽  
Small Effect Size ◽  
Endocrine Status ◽  
Meta Analyses

AbstractOsteoporosis is a common skeletal disease, affecting ~200 million people around the world. As a complex disease, osteoporosis is influenced by many factors, including diet (e.g. calcium and protein intake), physical activity, endocrine status, coexisting diseases and genetic factors. In this review, we first summarize the discovery from genome-wide association studies (GWASs) in the bone field in the last 12 years. To date, GWASs and meta-analyses have discovered hundreds of loci that are associated with bone mineral density (BMD), osteoporosis, and osteoporotic fractures. However, the GWAS approach has sometimes been criticized because of the small effect size of the discovered variants and the mystery of missing heritability, these two questions could be partially explained by the newly raised conceptual models, such as omnigenic model and natural selection. Finally, we introduce the clinical use of GWAS findings in the bone field, such as the identification of causal clinical risk factors, the development of drug targets and disease prediction. Despite the fruitful GWAS discoveries in the bone field, most of these GWAS participants were of European descent, and more genetic studies should be carried out in other ethnic populations to benefit disease prediction in the corresponding population.

Oxidized low-density lipoprotein and 15-deoxy-Δ12,14-PGJ2 increase mitochondrial complex I activity in endothelial cells

2003 ◽  
Vol 285 (6) ◽  
pp. H2298-H2308 ◽  
Author(s):  
Erin K. Ceaser ◽  
Anup Ramachandran ◽  
Anna-Liisa Levonen ◽  
Victor M. Darley-Usmar
Keyword(s):  
Endothelial Cells ◽  
Complex I ◽  
Citrate Synthase ◽  
Umbilical Vein ◽  
Oxidized Ldl ◽  
Antioxidant Defenses ◽  
Oxidized Lipids ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Complex I Activity

Oxidized lipids are capable of initiating diverse cellular responses through both receptor-mediated mechanisms and direct posttranslational modification of proteins. Typically, exposure of cells to low concentrations of oxidized lipids induces cytoprotective pathways, whereas high concentrations result in apoptosis. Interestingly, mitochondria can contribute to processes that result in either cytoprotection or cell death. The role of antioxidant defenses such as glutathione in adaptation to stress has been established, but the potential interaction with mitochondrial function is unknown and is examined in this article. Human umbilical vein endothelial cells (HUVEC) were exposed to oxidized LDL (oxLDL) or the electrophilic cyclopentenone 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2). We demonstrate that complex I activity, but not citrate synthase or cytochrome- c oxidase, is significantly induced by oxLDL and 15d-PGJ2. The mechanism is not clear at present but is independent of the induction of GSH, peroxisome proliferator-activated receptor (PPAR)-γ, and PPAR-α. This response is dependent on the induction of oxidative stress in the cells because it can be prevented by nitric oxide, probucol, and the SOD mimetic manganese(III) tetrakis(4-benzoic acid) porphyrin chloride. This increased complex I activity appears to contribute to protection against apoptosis induced by 4-hydroxynonenal.

scholarly journals Differences in Cardiac Energetics Between Patients With Familial and Nonfamilial Hypertrophic Cardiomyopathy

Circulation ◽  
2000 ◽  
Vol 101 (12) ◽  
Author(s):  
Wulf-Ingo Jung ◽  
Thomas Hoess ◽  
Michael Bunse ◽  
Stefan Widmaier ◽  
Ludger Sieverding ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Cardiac Energetics

scholarly journals Inflammatory Bowel Disease Through the Lens of Single-cell RNA-seq Technologies

2020 ◽  
Vol 26 (11) ◽  
pp. 1658-1668 ◽  
Author(s):  
Daniele Corridoni ◽  
Thomas Chapman ◽  
Agne Antanaviciute ◽  
Jack Satsangi ◽  
Alison Simmons
Keyword(s):  
Inflammatory Bowel Disease ◽  
Single Cell ◽  
Intestinal Mucosa ◽  
Bowel Disease ◽  
Drug Targets ◽  
Complex Disease ◽  
Cell Types ◽  
Inflammatory Bowel ◽  
Mucosa Cell ◽  
Definition Of

Abstract The intestinal mucosa represents a unique environment where the coordinated function of diverse epithelial, mesenchymal, and immune cells maintains a physiologically balanced environment in the presence of gut microbiota. The intestinal mucosa plays a central role in the pathogenesis of inflammatory bowel disease (IBD), yet the molecular and cellular composition of this diverse environment is poorly understood. However, the recent advent of multimodal single-cell technologies, including single-cell RNA sequencing (scRNA-seq), now provides an opportunity to accurately map the tissue architecture, characterize rare cell types that were previously overlooked, and define function at a single-cell level. In this review, we summarize key advances in single-cell technology and provide an overview of important aspects of computational analysis. We describe emerging data in the field of IBD and discuss how the characterization of novel intestinal mucosa cell populations is reshaping our understanding of this complex disease. We conclude by considering the potential clinical applications, including the definition of novel drug targets and the opportunity for personalization of care in this exciting new era of precision medicine.

Function and bioenergetics in isolated perfused trained rat hearts

1997 ◽  
Vol 272 (1) ◽  
pp. H409-H417 ◽  
Author(s):  
R. G. Spencer ◽  
P. M. Buttrick ◽  
J. S. Ingwall
Keyword(s):  
Diastolic Function ◽  
Citrate Synthase ◽  
Recovery Of Function ◽  
Complete Recovery ◽  
High Energy ◽  
Left Ventricular ◽  
Female Rats ◽  
Saturation Transfer

To evaluate the resistance of physiologically hypertrophied hearts to hypoxic insult, we quantified the development of functional deficits during hypoxia and reoxygenation in hypertrophied hearts from swim-trained female rats and we correlated this with assessment of high-energy phosphate (HEP) metabolites from simultaneous 31P nuclear magnetic resonance (NMR) measurements. Furthermore, in vivo enzymatic studies were carried out with saturation transfer NMR under well-oxygenated perfusion conditions for both beating and KCl-arrested hearts. Finally, in vitro enzymatic assays were performed. During hypoxia, the trained hearts exhibited improved systolic and diastolic function compared with hearts from sedentary animals. After 16 min of hypoxia, left ventricular (LV) developed pressure fell to 9% of baseline in control hearts but to only 21% of baseline in trained hearts (P < 0.01). LV diastolic function was also improved by training, increasing during hypoxia from a baseline of 10 to 71.0 +/- 3.3 mmHg in control hearts and to 55.3 +/- 4.8 mmHg in trained hearts (P < 0.05). Trained hearts also showed more rapid and complete recovery of function during reoxygenation and greater coronary flow per gram of heart throughout the entire protocol. Functional differences were not accompanied by differences in HEP at baseline; moreover, ATP and phosphocreatine (PCr) loss during hypoxia was similar between control and trained hearts, as was the recovery of PCr during reoxygenation. Saturation transfer experiments showed an increase in the forward creatine kinase (CrK) rate constant in trained hearts of 18% while beating, whereas in vitro enzymatic analysis revealed a 16% increase in the ratio of mitochondrial CrK to citrate synthase activity in LV tissue. Thus the relative preservation of function in hearts from trained rats could not be accounted for by overall HEP levels but may reflect adaptations in the CrK system.

scholarly journals Preclinical alterations in cardiac energetics amongst sarcomere mutation carriers in hypertrophic cardiomyopathy

2015 ◽  
Vol 17 (S1) ◽  
Author(s):  
Rachael Lloyd ◽  
Suchi Grover ◽  
Susie F Parnham ◽  
Pey Wen Lou ◽  
Craig Bradbrook ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Cardiac Energetics ◽  
Mutation Carriers

scholarly journals MYBPC3 Haplotype Linked to Hypertrophic Cardiomyopathy in Rhesus Macaques (Macaca mulatta)

2020 ◽  
Vol 70 (5) ◽  
pp. 358-367
Author(s):  
Robert F Oldt ◽  
Kimberly J Bussey ◽  
Matthew L Settles ◽  
Joseph N Fass ◽  
Jeffrey A Roberts ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Sudden Cardiac Death ◽  
Cardiac Death ◽  
Complex Disease ◽  
Rhesus Macaques ◽  
Amplicon Sequencing ◽  
Cardiovascular Disorder ◽  
Left Ventricular ◽  
Risk Haplotype ◽  
Wide Range

In humans, abnormal thickening of the left ventricle of the heart clinically defines hypertrophic cardiomyopathy (HCM), a common inherited cardiovascular disorder that can precede a sudden cardiac death event. The wide range of clinical presentations in HCM obscures genetic variants that may influence an individual's susceptibility to sudden cardiac death. Although exon sequencing of major sarcomere genes can be used to detect high-impact causal mutations, this strategy is successful in only half of patient cases. The incidence of left ventricular hypertrophy (LVH) in a managed research colony of rhesus macaques provides an excellent comparative model in which to explore the genomic etiology of severe HCM and sudden cardiac death. Because no rhesus HCM-associated mutations have been reported, we used a next-generation genotyping assay that targets 7 sarcomeric rhesus genes within 63 genomic sites that are orthologous to human genomic regions known to harbor HCM disease variants. Amplicon sequencing was performed on 52 macaques with confirmed LVH and 42 unrelated, unaffected animals representing both the Indian and Chinese rhesus macaque subspecies. Bias-reduced logistic regression uncovered a risk haplotype in the rhesus MYBPC3 gene, which is frequently disrupted in both human and feline HCM; this haplotype implicates an intronic variant strongly associated with disease in either homozygous or carrier form. Our results highlight that leveraging evolutionary genomic data provides a unique, practical strategy for minimizing population bias in complex disease studies.

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