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1.
Physiol Rep ; 12(17): e70045, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39252180

Asunto(s)
Fisiología , Australia , Humanos
2.
Dis Model Mech ; 17(8)2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39189070

RESUMEN

Hypertrophic cardiomyopathy (HCM) is an inherited heart muscle disease that is characterised by left ventricular wall thickening, cardiomyocyte disarray and fibrosis, and is associated with arrhythmias, heart failure and sudden death. However, it is unclear to what extent the electrophysiological disturbances that lead to sudden death occur secondary to structural changes in the myocardium or as a result of HCM cardiomyocyte electrophysiology. In this study, we used an induced pluripotent stem cell model of the R403Q variant in myosin heavy chain 7 (MYH7) to study the electrophysiology of HCM cardiomyocytes in electrically coupled syncytia, revealing significant conduction slowing and increased spatial dispersion of repolarisation - both well-established substrates for arrhythmia. Analysis of rhythmonome protein expression in MYH7 R403Q cardiomyocytes showed reduced expression of connexin-43 (also known as GJA1), sodium channels and inward rectifier potassium channels - a three-way hit that reduces electrotonic coupling and slows cardiac conduction. Our data represent a previously unreported, biophysical basis for arrhythmia in HCM that is intrinsic to cardiomyocyte electrophysiology. Later in the progression of the disease, these proarrhythmic phenotypes may be accentuated by myocyte disarray and fibrosis to contribute to sudden death.


Asunto(s)
Cardiomiopatía Hipertrófica , Conexina 43 , Sistema de Conducción Cardíaco , Miocitos Cardíacos , Cadenas Pesadas de Miosina , Conexina 43/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Humanos , Cardiomiopatía Hipertrófica/patología , Cardiomiopatía Hipertrófica/metabolismo , Cardiomiopatía Hipertrófica/fisiopatología , Cadenas Pesadas de Miosina/metabolismo , Cadenas Pesadas de Miosina/genética , Sistema de Conducción Cardíaco/metabolismo , Sistema de Conducción Cardíaco/fisiopatología , Células Madre Pluripotentes Inducidas/metabolismo , Miosinas Cardíacas/metabolismo , Miosinas Cardíacas/genética , Células Gigantes/metabolismo , Células Gigantes/patología , Arritmias Cardíacas/patología , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatología , Potenciales de Acción
3.
Stem Cell Res Ther ; 14(1): 345, 2023 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-38049901

RESUMEN

BACKGROUND: Genomic sequencing in congenital heart disease (CHD) patients often discovers novel genetic variants, which are classified as variants of uncertain significance (VUS). Functional analysis of each VUS is required in specialised laboratories, to determine whether the VUS is disease causative or not, leading to lengthy diagnostic delays. We investigated stem cell cardiac disease modelling and transcriptomics for the purpose of genetic variant classification using a GATA4 (p.Arg283Cys) VUS in a patient with CHD. METHODS: We performed high efficiency CRISPR gene editing with homology directed repair in induced pluripotent stem cells (iPSCs), followed by rapid clonal selection with amplicon sequencing. Genetic variant and healthy matched control cells were compared using cardiomyocyte disease modelling and transcriptomics. RESULTS: Genetic variant and healthy cardiomyocytes similarly expressed Troponin T (cTNNT), and GATA4. Transcriptomics analysis of cardiomyocyte differentiation identified changes consistent with the patient's clinical human phenotype ontology terms. Further, transcriptomics revealed changes in calcium signalling, and cardiomyocyte adrenergic signalling in the variant cells. Functional testing demonstrated, altered action potentials in GATA4 genetic variant cardiomyocytes were consistent with patient cardiac abnormalities. CONCLUSIONS: This work provides in vivo functional studies supportive of a damaging effect on the gene or gene product. Furthermore, we demonstrate the utility of iPSCs, CRISPR gene editing and cardiac disease modelling for genetic variant interpretation. The method can readily be applied to other genetic variants in GATA4 or other genes in cardiac disease, providing a centralised assessment pathway for patient genetic variant interpretation.


Asunto(s)
Edición Génica , Cardiopatías Congénitas , Humanos , Cardiopatías Congénitas/genética , Cardiopatías Congénitas/metabolismo , Miocitos Cardíacos/metabolismo , Secuencia de Bases , Transducción de Señal
4.
Sci Rep ; 13(1): 11296, 2023 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-37438479

RESUMEN

Familial hypertrophic cardiomyopathy (FHC) patients are advised to avoid strenuous exercise due to increased risk of arrhythmias. Mice expressing the human FHC-causing mutation R403Q in the myosin heavy chain gene (MYH6) recapitulate the human phenotype, including cytoskeletal disarray and increased arrhythmia susceptibility. Following in vivo administration of isoproterenol, mutant mice exhibited tachyarrhythmias, poor recovery and fatigue. Arrhythmias were attenuated with the ß-blocker atenolol and protein kinase A inhibitor PKI. Mutant cardiac myocytes had significantly prolonged action potentials and triggered automaticity due to reduced repolarization reserve and connexin 43 expression. Isoproterenol shortened cycle length, and escalated electrical instability. Surprisingly isoproterenol did not increase CaV1.2 current. We found alterations in CaV1.2-ß1 adrenergic receptor colocalization assessed using super-resolution nanoscopy, and increased CaV1.2 phosphorylation in mutant hearts. Our results reveal for the first time that altered ion channel expression, co-localization and ß-adrenergic receptor signaling associated with myocyte disarray contribute to electrical instability in the R403Q mutant heart.


Asunto(s)
Cardiomiopatía Hipertrófica Familiar , Cardiomiopatía Hipertrófica , Humanos , Animales , Ratones , Isoproterenol , Cardiomiopatía Hipertrófica/genética , Arritmias Cardíacas , Corazón
5.
Commun Biol ; 6(1): 4, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36596888

RESUMEN

Hypertrophic cardiomyopathy is an inherited disorder due to mutations in contractile proteins that results in a stiff, hypercontractile myocardium. To understand the role of cardiac stiffness in disease progression, here we create an in vitro model of hypertrophic cardiomyopathy utilizing hydrogel technology. Culturing wild-type cardiac myocytes on hydrogels with a Young's Moduli (stiffness) mimicking hypertrophic cardiomyopathy myocardium is sufficient to induce a hypermetabolic mitochondrial state versus myocytes plated on hydrogels simulating healthy myocardium. Significantly, these data mirror that of myocytes isolated from a murine model of human hypertrophic cardiomyopathy (cTnI-G203S). Conversely, cTnI-G203S myocyte mitochondrial function is completely restored when plated on hydrogels mimicking healthy myocardium. We identify a mechanosensing feedback mechanism between the extracellular matrix and cytoskeletal network that regulates mitochondrial function under healthy conditions, but participates in the progression of hypertrophic cardiomyopathy pathophysiology resulting from sarcomeric gene mutations. Importantly, we pinpoint key 'linker' sites in this schema that may represent potential therapeutic targets.


Asunto(s)
Cardiomiopatía Hipertrófica , Ratones , Humanos , Animales , Retroalimentación , Cardiomiopatía Hipertrófica/genética , Cardiomiopatía Hipertrófica/metabolismo , Citoesqueleto/metabolismo , Miocitos Cardíacos/metabolismo , Troponina I/genética , Troponina I/metabolismo , Matriz Extracelular/metabolismo , Hidrogeles
7.
J Biomed Mater Res A ; 111(6): 801-813, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36239543

RESUMEN

Present understandings of cardiomyocyte mechanobiology have primarily been developed using 2-dimensional, monocellular cell cultures, however the emergence of 3-dimensional (3D) multicellular cardiac constructs has enabled us to develop more sophisticated recapitulations of the cardiac microenvironment. Several of these strategies have illustrated that incorporating elements of the extracellular matrix (ECM) can promote greater maturation and enhance desirable cardiac functions, such as contractility, but the responses of these cardiac constructs to biophysically aberrant conditions, such as in the post-infarct heart, has remained relatively unexplored. In our study, we employ a stiffness gradient gelatin methacryloyl (GelMA) hydrogel platform to unpack the mechanobiology of cardiac spheroids. We encapsulated neonatal rat cardiac cell spheroids in a 4.4-18.7 kPa linear stiffness gradient up to 120 h. We found the proportion of viable cells within the spheroids increased over time, but the cell number per spheroid decreased. Spheroids expand more in softer matrices while stiffer matrices promote larger nuclei without changing nuclei shape. Volume expansion came primarily from cells expressing vimentin. We did not observe any correlations between stiffness and mechanomarker expression, however we found that after 120 h post-encapsulation, the localization of YAP, the localization of MRTF-A and the expression of Lamin-A was correlated with spheroid morphology. The same trends were not observed 24 h post-encapsulation, indicating that volume adaptation can take a relatively long time. Our data demonstrates that cardiac spheroids are mechanosensitive and that their capacity to respond to ECM-based cues depends on their capacity to adapt their volume with a 3D microenvironment.


Asunto(s)
Gelatina , Miocitos Cardíacos , Animales , Ratas , Gelatina/metabolismo , Metacrilatos , Matriz Extracelular/metabolismo , Esferoides Celulares , Hidrogeles/metabolismo
8.
Biomater Sci ; 10(22): 6628-6629, 2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36285837

RESUMEN

Correction for 'Interrogating cardiac muscle cell mechanobiology on stiffness gradient hydrogels' by Ian L. Chin et al., Biomater. Sci., 2021, 9, 6795-6806, https://doi.org/10.1039/D1BM01061A.

9.
Philos Trans R Soc Lond B Biol Sci ; 377(1864): 20210324, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36189806

RESUMEN

Mitochondria are ubiquitous organelles that play a pivotal role in the supply of energy through the production of adenosine triphosphate in all eukaryotic cells. The importance of mitochondria in cells is demonstrated in the poor survival outcomes observed in patients with defects in mitochondrial gene or RNA expression. Studies have identified that mitochondria are influenced by the cell's cytoskeletal environment. This is evident in pathological conditions such as cardiomyopathy where the cytoskeleton is in disarray and leads to alterations in mitochondrial oxygen consumption and electron transport. In cancer, reorganization of the actin cytoskeleton is critical for trans-differentiation of epithelial-like cells into motile mesenchymal-like cells that promotes cancer progression. The cytoskeleton is critical to the shape and elongation of neurons, facilitating communication during development and nerve signalling. Although it is recognized that cytoskeletal proteins physically tether mitochondria, it is not well understood how cytoskeletal proteins alter mitochondrial function. Since end-stage disease frequently involves poor energy production, understanding the role of the cytoskeleton in the progression of chronic pathology may enable the development of therapeutics to improve energy production and consumption and slow disease progression. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.


Asunto(s)
Proteínas del Citoesqueleto , Neoplasias , Adenosina Trifosfato/metabolismo , Fenómenos Fisiológicos Celulares , Proteínas del Citoesqueleto/metabolismo , Humanos , Mitocondrias/metabolismo , Neoplasias/metabolismo , ARN/metabolismo
10.
J Mol Cell Cardiol ; 172: 100-108, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36041287

RESUMEN

Cardiovascular disease continues to be the leading health burden worldwide and with the rising rates in obesity and type II diabetes and ongoing effects of long COVID, it is anticipated that the burden of cardiovascular morbidity and mortality will increase. Calcium is essential to cardiac excitation and contraction. The main route for Ca2+ influx is the L-type Ca2+ channel (Cav1.2) and embryos that are homozygous null for the Cav1.2 gene are lethal at day 14 postcoitum. Acute changes in Ca2+ influx through the channel contribute to arrhythmia and sudden death, and chronic increases in intracellular Ca2+ contribute to pathological hypertrophy and heart failure. We use a multidisciplinary approach to study the regulation of the channel from the molecular level through to in vivo CRISPR mutant animal models. Here we describe some examples of our work from over 2 decades studying the role of the channel under physiological and pathological conditions. Our single channel analysis of purified human Cav1.2 protein in proteoliposomes has contributed to understanding direct molecular regulation of the channel including identifying the critical serine involved in the "fight or flight" response. Using the same approach we identified the cysteine responsible for altered function during oxidative stress. Chronic activation of the L-type Ca2+ channel during oxidative stress occurs as a result of persistent glutathionylation of the channel that contributes to the development of hypertrophy. We describe for the first time that activation of the channel alters mitochondrial function (and energetics) on a beat-to-beat basis via movement of cytoskeletal proteins. In translational studies we have used this response to "report" mitochondrial function in models of cardiomyopathy and to test efficacy of novel therapies to prevent cardiomyopathy.


Asunto(s)
Canales de Calcio Tipo L , Cardiomiopatías , Animales , Humanos , Calcio/metabolismo , Canales de Calcio Tipo L/fisiología , Cardiomiopatías/metabolismo , COVID-19 , Diabetes Mellitus Tipo 2/metabolismo , Hipertrofia/metabolismo , Miocitos Cardíacos/metabolismo , Síndrome Post Agudo de COVID-19
11.
Mater Today Bio ; 16: 100391, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36042852

RESUMEN

With the adoption of 3-dimensional (3D) cell culture for in vitro modelling of cardiac function and regenerative medicine applications, there is an increased need to understand cardiomyocyte mechanosensation in 3D. With existing studies of cardiomyocyte mechanosensation primarily focussed on the behaviour of individual cells in a 2-Dimensional context, it is unclear whether mechanosensation is the same in a 3D, multicellular context. In this study, H9C2 cardiac-derived myoblasts were encapsulated as individual cells and as cell spheroids within stiffness gradient gelatin methacryloyl (GelMA) hydrogels to investigate individual and collective cardiac cell mechanosensation in 3D. Over a 3.68-17.52 â€‹kPa stiffness range, it was found that H9C2 cells have a limited capacity to adapt their volume to increasing substrate stiffness, demonstrated by the lack of changes in cell volume and shape across the stiffness gradient. Morphological trends were reflected by the expression of the mechanomarkers YAP, MRTF-A and Lamin-A, which were better correlated with cell and nuclear volume than with substrate stiffness. The localisation of YAP and MRTF-A were dependent on the relative volumes of the cytoplasm and nucleus while Lamin-A expression was elevated with increasing cytoplasmic and nuclear volumes. When cultured as spheroids rather than as individual cells, H9C2 cells adopted a distinct morphology with comparably smaller nuclei than individually cultured cells, while retaining the same overall cell volume. As spheroids, H9C2 cells were sensitive to stiffness cues, shown by decreasing YAP and MRTF-A nuclear localisation, increasing Lamin-A expression, and increasing vinculin expression with increasing substrate stiffness. Like the individually cultured H9C2 cells, mechanomarker expression was correlated to volume adaptation. With increasing cytoplasmic volume, YAP and MRTF-A became less nuclear localised, vinculin expression was increased, and with increasing nuclear volume, the Lamin-A expression fincreased. Together, these data suggest that cardiac cell volume adaptation may be enhanced by cell-cell interactions.

12.
Biomater Sci ; 9(20): 6795-6806, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-34542112

RESUMEN

Extracellular matrix (ECM) remodeling is a major facet of cardiac development and disease, yet our understanding of cardiomyocyte mechanotransduction remains limited. To enhance our understanding of cardiomyocyte mechanosensation, we studied stiffness-driven changes to cell morphology and mechanomarker expression in H9C2 cells and neonatal rat cardiomyocytes (NRCMs). Linear stiffness gradient polyacrylamide hydrogels (2-33 kPa) coated with ECM proteins including Collagen I (Col), Fibronectin (Fn) or Laminin (Ln) were used to represent necrotic, healthy, and infarcted cardiac tissue on a continuous stiffness gradient. Cell size, cell shape and nuclear size were found to be mechanosensitive in H9C2 cells, as was the expression or nuclear translocalization of the mechanomarkers Lamin-A, YAP, and MRTF-A. Minor differences were observed between the different ECM coatings, with the same overarching stiffness-dependent trends being observed across Col, Fn and Ln coated hydrogels. Inhibition of mechanotransduction in H9C2 cells using blebbistatin or Y27632 resulted in disruptions to cell shape, nuclear shape, and nuclear size, however, trends in cell size and mechanomarker expression were not significantly attenuated. Mechanosensation in NRCMs was much less marked, with no significant changes in cell morphology being detected, although YAP did become increasingly nuclear localized with increasing stiffness. In α-actinin positive cells, striations formed with regular structure and frequency at all stiffnesses for Col and Fn coated hydrogels, but not Ln coated gels. In this study, we used our stiffness gradient hydrogels to comprehensively map the relationship between ECM stiffness and cardiac cell phenotype and found that less mature H9C2 cardiac cells are more sensitive to ECM changes than the more developed neonatal cardiomyocytes.


Asunto(s)
Hidrogeles , Miocitos Cardíacos , Animales , Biofisica , Matriz Extracelular , Mecanotransducción Celular , Ratas
13.
Sci Adv ; 7(39): eabi7514, 2021 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-34559558

RESUMEN

Mitochondrial energy metabolism plays an important role in the pathophysiology of insulin resistance. Recently, a missense N437S variant was identified in the MRPP3 gene, which encodes a mitochondrial RNA processing enzyme within the RNase P complex, with predicted impact on metabolism. We used CRISPR-Cas9 genome editing to introduce this variant into the mouse Mrpp3 gene and show that the variant causes insulin resistance on a high-fat diet. The variant did not influence mitochondrial gene expression markedly, but instead, it reduced mitochondrial calcium that lowered insulin release from the pancreatic islet ß cells of the Mrpp3 variant mice. Reduced insulin secretion resulted in lower insulin levels that contributed to imbalanced metabolism and liver steatosis in the Mrpp3 variant mice on a high-fat diet. Our findings reveal that the MRPP3 variant may be a predisposing factor to insulin resistance and metabolic disease in the human population.

14.
J Physiol ; 599(14): 3447-3448, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34263447

Asunto(s)
Mitocondrias , Humanos
16.
Aging Cell ; 20(7): e13408, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34096683

RESUMEN

Changes in the rate and fidelity of mitochondrial protein synthesis impact the metabolic and physiological roles of mitochondria. Here we explored how environmental stress in the form of a high-fat diet modulates mitochondrial translation and affects lifespan in mutant mice with error-prone (Mrps12ep/ep ) or hyper-accurate (Mrps12ha/ha ) mitochondrial ribosomes. Intriguingly, although both mutations are metabolically beneficial in reducing body weight, decreasing circulating insulin and increasing glucose tolerance during a high-fat diet, they manifest divergent (either deleterious or beneficial) outcomes in a tissue-specific manner. In two distinct organs that are commonly affected by the metabolic disease, the heart and the liver, Mrps12ep/ep mice were protected against heart defects but sensitive towards lipid accumulation in the liver, activating genes involved in steroid and amino acid metabolism. In contrast, enhanced translational accuracy in Mrps12ha/ha mice protected the liver from a high-fat diet through activation of liver proliferation programs, but enhanced the development of severe hypertrophic cardiomyopathy and led to reduced lifespan. These findings reflect the complex transcriptional and cell signalling responses that differ between post-mitotic (heart) and highly proliferative (liver) tissues. We show trade-offs between the rate and fidelity of mitochondrial protein synthesis dictate tissue-specific outcomes due to commonly encountered stressful environmental conditions or aging.


Asunto(s)
Enfermedades Cardiovasculares/genética , Mitocondrias/metabolismo , Estrés Fisiológico/genética , Animales , Humanos , Longevidad , Masculino , Ratones
17.
J Physiol ; 599(14): 3495-3512, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-32822065

RESUMEN

Sarcomeric gene mutations are associated with the development of hypertrophic cardiomyopathy (HCM). Current drug therapeutics for HCM patients are effective in relieving symptoms, but do not prevent or reverse disease progression. Moreover, due to heterogeneity in the clinical manifestations of the disease, patients experience variable outcomes in response to therapeutics. Mechanistically, alterations in calcium handling, sarcomeric disorganization, energy metabolism and contractility participate in HCM disease progression. While some similarities exist, each mutation appears to lead to mutation-specific pathophysiology. Furthermore, these alterations may precede or proceed development of the pathology. This review assesses the efficacy of HCM therapeutics from studies performed in animal models of HCM and human clinical trials. Evidence suggests that a preventative rather than corrective therapeutic approach may be more efficacious in the treatment of HCM. In addition, a clear understanding of mutation-specific mechanisms may assist in informing the most effective therapeutic mode of action.


Asunto(s)
Cardiomiopatía Hipertrófica , Animales , Calcio/metabolismo , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Cardiomiopatía Hipertrófica/genética , Metabolismo Energético , Humanos , Mutación , Sarcómeros/metabolismo
18.
J Physiol ; 599(14): 3449-3462, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-32710561

RESUMEN

The evolutionary acquisition of mitochondria has given rise to the diversity of eukaryotic life. Mitochondria have retained their ancestral α-proteobacterial traits through the maintenance of double membranes and their own circular genome. Their genome varies in size from very large in plants to the smallest in animals and their parasites. The mitochondrial genome encodes essential genes for protein synthesis and has to coordinate its expression with the nuclear genome from which it sources most of the proteins required for mitochondrial biogenesis and function. The mitochondrial protein synthesis machinery is unique because it is encoded by both the nuclear and mitochondrial genomes thereby requiring tight regulation to produce the respiratory complexes that drive oxidative phosphorylation for energy production. The fidelity and coordination of mitochondrial protein synthesis are essential for ATP production. Here we compare and contrast the mitochondrial translation mechanisms in mammals and fungi to bacteria and reveal that their diverse regulation can have unusual impacts on the health and disease of these organisms. We highlight that in mammals the rate of protein synthesis is more important than the fidelity of translation, enabling coordinated biogenesis of the mitochondrial respiratory chain with respiratory chain proteins synthesised by cytoplasmic ribosomes. Changes in mitochondrial protein fidelity can trigger the activation of the diverse cellular signalling networks in fungi and mammals to combat dysfunction in energy conservation. The physiological consequences of altered fidelity of protein synthesis can range from liver regeneration to the onset and development of cardiomyopathy.


Asunto(s)
Genoma Mitocondrial , Biosíntesis de Proteínas , Animales , Mitocondrias/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Ribosomas/metabolismo
19.
Proc Natl Acad Sci U S A ; 117(37): 23113-23124, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32859761

RESUMEN

Currently there is an unmet need for treatments that can prevent hypertrophic cardiomyopathy (HCM). Using a murine model we previously identified that HCM causing cardiac troponin I mutation Gly203Ser (cTnI-G203S) is associated with increased mitochondrial metabolic activity, consistent with the human condition. These alterations precede development of the cardiomyopathy. Here we examine the efficacy of in vivo treatment of cTnI-G203S mice with a peptide derived against the α-interaction domain of the cardiac L-type calcium channel (AID-TAT) on restoring mitochondrial metabolic activity, and preventing HCM. cTnI-G203S or age-matched wt mice were treated with active or inactive AID-TAT. Following treatment, targeted metabolomics was utilized to evaluate myocardial substrate metabolism. Cardiac myocyte mitochondrial metabolic activity was assessed as alterations in mitochondrial membrane potential and flavoprotein oxidation. Cardiac morphology and function were examined using echocardiography. Cardiac uptake was assessed using an in vivo multispectral imaging system. We identified alterations in six biochemical intermediates in cTnI-G203S hearts consistent with increased anaplerosis. We also reveal that AID-TAT treatment of precardiomyopathic cTnI-G203S mice, but not mice with established cardiomyopathy, restored cardiac myocyte mitochondrial membrane potential and flavoprotein oxidation, and prevented myocardial hypertrophy. Importantly, AID-TAT was rapidly targeted to the heart, and not retained by the liver or kidneys. Overall, we identify biomarkers of HCM resulting from the cTnI mutation Gly203Ser, and present a safe, preventative therapy for associated cardiomyopathy. Utilizing AID-TAT to modulate cardiac metabolic activity may be beneficial in preventing HCM in "at risk" patients with identified Gly203Ser gene mutations.


Asunto(s)
Cardiomiopatía Hipertrófica/tratamiento farmacológico , Cardiomiopatía Hipertrófica/metabolismo , Animales , Calcio/metabolismo , Canales de Calcio Tipo L/metabolismo , Modelos Animales de Enfermedad , Humanos , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Mutación/genética , Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Péptidos/farmacología , Troponina I/metabolismo
20.
Heart Lung Circ ; 29(11): 1588-1595, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32839116

RESUMEN

BACKGROUND: Cardiovascular disease is the leading cause of death in Australia. Investment in research solutions has been demonstrated to yield health and a 9.8-fold return economic benefit. The sector, however, is severely challenged with success rates of traditional peer-reviewed funding in decline. Here, we aimed to understand the perceived challenges faced by the cardiovascular workforce in Australia prior to the COVID-19 pandemic. METHODS: We used an online survey distributed across Australian cardiovascular societies/councils, universities and research institutes over a period of 6 months during 2019, with 548 completed responses. Inclusion criteria included being an Australian resident or an Australian citizen who lived overseas, and a current or past student or employee in the field of cardiovascular research. RESULTS: The mean age of respondents was 42±13 years, 47% were male, 85% had a full-time position, and 40% were a group leader or laboratory head. Twenty-three per cent (23%) had permanent employment, and 82% of full-time workers regularly worked >40 hours/week. Sixty-eight per cent (68%) said they had previously considered leaving the cardiovascular research sector. If their position could not be funded in the next few years, a staggering 91% of respondents would leave the sector. Compared to PhD- and age-matched men, women were less likely to be a laboratory head and to feel they had a long-term career path as a cardiovascular researcher, while more women were unsure about future employment and had considered leaving the sector (all p<0.05). Greater job security (76%) and government and philanthropic investment in cardiovascular research (72%) were highlighted by responders as the main changes to current practices that would encourage them to stay. CONCLUSION: Strategic solutions, such as diversification of career pathways and funding sources, and moving from a competitive to a collaborative culture, need to be a priority to decrease reliance on government funding and allow cardiovascular researchers to thrive.


Asunto(s)
Investigación Biomédica , Enfermedades Cardiovasculares , Infecciones por Coronavirus/epidemiología , Administración Financiera , Neumonía Viral/epidemiología , Investigadores , Apoyo a la Investigación como Asunto , Recursos Humanos , Adulto , Australia , Betacoronavirus , Investigación Biomédica/economía , Investigación Biomédica/organización & administración , Investigación Biomédica/tendencias , COVID-19 , Empleo/economía , Empleo/psicología , Femenino , Administración Financiera/métodos , Administración Financiera/organización & administración , Administración Financiera/estadística & datos numéricos , Financiación Gubernamental , Humanos , Masculino , Cultura Organizacional , Pandemias , Técnicas de Planificación , Investigadores/economía , Investigadores/psicología , Investigadores/estadística & datos numéricos , Apoyo a la Investigación como Asunto/organización & administración , Apoyo a la Investigación como Asunto/tendencias , SARS-CoV-2 , Encuestas y Cuestionarios , Recursos Humanos/estadística & datos numéricos
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