Rationale: The nutrient sensing mechanistic target of rapamycin complex 1 (mTORC1) and its primary inhibitor, tuberin (TSC2), are cues for the development of cardiac hypertrophy. The phenotype of mTORC1 induced hypertrophy is unknown.
Objective: To examine the impact of sustained mTORC1 activation on metabolism, function, and structure of the adult heart.
Methods And Results: We developed a mouse model of inducible, cardiac-specific sustained mTORC1 activation (mTORC1) through deletion of Tsc2. Prior to hypertrophy, rates of glucose uptake and oxidation, as well as protein and enzymatic activity of glucose 6-phosphate isomerase (GPI) were decreased, while intracellular levels of glucose 6-phosphate (G6P) were increased. Subsequently, hypertrophy developed. Transcript levels of the fetal gene program and pathways of exercise-induced hypertrophy increased, while hypertrophy did not progress to heart failure. We therefore examined the hearts of wild-type mice subjected to voluntary physical activity and observed early changes in GPI, followed by hypertrophy. Rapamycin prevented these changes in both models.
Conclusion: Activation of mTORC1 in the adult heart triggers the development of a non-specific form of hypertrophy which is preceded by changes in cardiac glucose metabolism.
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http://dx.doi.org/10.1016/j.yjmcc.2021.05.016 | DOI Listing |
Acta Otolaryngol
January 2025
Department of Medicine, University of Turku, Turku, Finland.
Background: Large palatine tonsils cause a variety of symptoms including obstructive sleep apnea and snoring. In adults, the prevalence of tonsillar hypertrophy remains uncertain.
Aims: We estimated the incidence of tonsillectomy for adult palatine tonsillar hypertrophy using population data and retrospective patient charts.
Turk Kardiyol Dern Ars
January 2025
Department of Cardiology, Istanbul Basaksehir Cam and Sakura City Hospital, Basaksehir, Istanbul, Türkiye.
Objective: Although left ventricular hypertrophy frequently accompanies end-stage renal disease, heart failure (HF) with reduced ejection fraction (EF) is also observed in a subset of patients. In those patients kidney transplantation (KT) is generally avoided due to an increased risk of mortality in addition to the risks associated with HF. This prospective study was designed to follow patients with HF who were being prepared for KT.
View Article and Find Full Text PDFJ Clin Med
December 2024
Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy.
Even if rarely detected, right atrial (RA) masses represent a diagnostic challenge due to their heterogeneous presentation. Para-physiological RA structures, such as a prominent Eustachian valve, Chiari's network, and lipomatous atrial hypertrophy, may easily be misinterpreted as pathological RA masses, including thrombi, myxomas, and vegetations. Each pathological mass should always be correlated with adequate clinical, anamnestic, and laboratory data.
View Article and Find Full Text PDFChronic exposure to high altitudes causes pathophysiological cardiac changes that are characterized by cardiac dysfunction, cardiac hypertrophy, and decreased energy reserves. However, finding specific pharmacological interventions for these pathophysiological changes is challenging. In this study, we identified tetramethylpyrazine (TMP) as a promising drug candidate for cardiac dysfunction caused by simulated high-altitude exposure.
View Article and Find Full Text PDFDiagnostics (Basel)
January 2025
Department of Cardiology, Paphos General Hospital, State Health Organization Services, Paphos 8026, Cyprus.
Hypertension is a major risk factor of various cardiac complications, including hypertensive heart disease (HHD). This condition can lead to a number of structural and functional changes in the heart, such as left ventricular hypertrophy, diastolic dysfunction, and, eventually, systolic dysfunction. In the management of hypertensive heart disease, early diagnosis and appropriate treatment are crucial for preventing the progression to congestive heart failure.
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