Long-chain saturated fatty acids, especially palmitic acid (PA), contribute to cardiomyocyte lipotoxicity. This study tests the effects of PA on adult rat cardiomyocyte contractile function and proteins associated with calcium regulating cardiomyocyte contraction and relaxation. Adult rat cardiomyocytes were pretreated with resveratrol (Resv) and then treated with PA. For the reversal study, cardiomyocytes were incubated with PA prior to treatment with Resv. Cardiomyocyte contractility, ratio of rod- to round-shaped cardiomyocytes, and Hoechst staining were used to measure functional and morphological changes in cardiomyocytes. Protein expression of sarco-endoplasmic reticulum ATPase 2a (SERCA2a), native phospholamban (PLB) and phosphorylated PLB (pPLB ser16 and pPLB thr17), and troponin I (TnI) and phosphorylated TnI (pTnI) were measured. SERCA2a activity was also measured. Our results show that PA (200 μM) decreased the rate of cardiomyocyte relaxation, reduced the number of rod-shaped cardiomyocytes, and increased the number of cells with condensed nuclei; pre-treating cardiomyocytes with Resv significantly prevented these changes. Post-treatment with Resv did not reverse morphological changes induced by PA. Protein expression levels of SERCA2a, PLB, pPLBs, TnI, and pTnI were unchanged by PA or Resv. SERCA2a activity assay showed that and Iono ratio were increased with PA and pre-treatment with Resv prevented this increase. In conclusion, our results show that Resv protect cardiomyocytes from contractile dysfunction induced by PA.
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http://dx.doi.org/10.1139/cjpp-2019-0051 | DOI Listing |
J Mol Cell Cardiol Plus
September 2024
O'Brien Institute Department, St Vincent's Institute of Medical Research, Victoria 3065, Australia.
Dynamin-related protein 1 (Drp1) is a mitochondrial fission protein and a viable target for cardioprotection against myocardial ischaemia-reperfusion injury. Here, we reported a novel Drp1 inhibitor (DRP1i1), delivered using a cardiac-targeted nanoparticle drug delivery system, as a more effective approach for achieving acute cardioprotection. DRP1i1 was encapsulated in cubosome nanoparticles with conjugated cardiac-homing peptides (NanoDRP1i1) and the encapsulation efficiency was 99.
View Article and Find Full Text PDFThe cardioprotective effects of histone deacetylase (HDAC) inhibitors (HDIs) are at odds with the deleterious effects of HDAC depletion. Here, we use HDAC3 as a prototype HDAC to address this contradiction. We show that adult-onset cardiac-specific depletion of HDAC3 in mice causes cardiac hypertrophy and contractile dysfunction on a high-fat diet (HFD), excluding developmental disruption as a major reason for the contradiction.
View Article and Find Full Text PDFLife Sci
January 2025
Department of Cardiology, Cardiac Arrhythmia Center, Affiliated Hospital of Nantong University, Nantong 226001, China. Electronic address:
Doxorubicin (DOX), a chemotherapeutic agent utilized in the management of cancer, provokes cardiotoxicity although effective remedy is lacking. Given that DOX provokes oxidative stress and cell death in cardiomyocytes, this study evaluated the possible involvement of cuproptosis, a newly identified form of cell death, in DOX-instigated cardiac remodeling and contractile dysfunction, alongside the impact of the heavy metal scavenger metallothionein (MT) on DOX cardiomyopathy. Cardiac-specific MT transgenic and wild-type (WT) mice were treated with DOX (5 mg/kg/wk.
View Article and Find Full Text PDFJ Mol Cell Cardiol
January 2025
Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA; Institute of Engineering Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92093, USA. Electronic address:
Vinculin (VCL) is a key adapter protein located in force-bearing costamere complexes, which mechanically couples the sarcomere to the ECM. Heterozygous vinculin frameshift genetic variants can contribute to cardiomyopathy when external stress is applied, but the mechanosensitive pathways underpinning VCL haploinsufficiency remain elusive. Here, we show that in response to extracellular matrix stiffening, heterozygous loss of VCL disrupts force-mediated costamere protein recruitment, thereby impairing cardiomyocyte contractility and sarcomere organization.
View Article and Find Full Text PDFJ Exp Biol
January 2025
Hannover Medical School, Institute of Functional and Applied Anatomy, 30625 Hanover, Germany.
Small mammals have a higher heart rate and, relative to body mass (Mb), a higher metabolic rate than large mammals. In contrast, heart weight and stroke volume scale linearly with Mb. With mitochondria filling approximately 50% of a shrew cardiomyocyte - space unavailable for myofibrils - it is unclear how small mammals generate enough contractile force to pump blood into circulation.
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