Cyclin-dependent kinase 1 () is a master regulator of the G2-M transition between DNA replication and cell division. This study investigates the regulation of cardiomyocyte (CM) proliferation during the early neonatal period and following ischemic injury in adult mice. We analyzed cell cycle dynamics with the assessment of DNA synthesis, and cytokinesis in murine hearts during the first 15 days after birth.
View Article and Find Full Text PDFNeutrophils are not only involved in immune defense against infection but also contribute to the exacerbation of tissue damage after ischemia and reperfusion. We have previously shown that genetic ablation of regulatory Gα proteins in mice has both protective and deleterious effects on myocardial ischemia reperfusion injury (mIRI), depending on which isoform is deleted. To deepen and analyze these findings in more detail the contribution of Gα proteins in resident cardiac vs circulating blood cells for mIRI was first studied in bone marrow chimeras.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
March 2024
Heart failure with preserved ejection fraction (HFpEF) afflicts over half of all patients with heart failure and is a debilitating and fatal syndrome affecting postmenopausal women more than any other demographic. This bias toward older females calls into question the significance of menopause in the development of HFpEF, but this question has not been probed in detail. In this study, we report the first investigation into the impact of ovary-intact menopause in the context of HFpEF.
View Article and Find Full Text PDFBackground: Doxorubicin-induced cardiomyopathy (DICM) is one of the complications that can limit treatment for a significant number of cancer patients. In animal models, the administration of statins can prevent the development of DICM. Therefore, the use of statins with anthracyclines potentially could enable cancer patients to complete their chemotherapy without added cardiotoxicity.
View Article and Find Full Text PDFAdult mammalian cardiomyocytes (CM) are postmitotic, differentiated cells that cannot re-enter the cell cycle after any appreciable injury. Therefore, understanding the factors required to induce CM proliferation for repair is of great clinical importance. While expression of muscle pyruvate kinase 2 (Pkm2), a cytosolic enzyme catalyzing the final step in glycolysis, is high in end-stage heart failure (HF), the loss of Pkm2 promotes proliferation in some cellular systems, in vivo.
View Article and Find Full Text PDFThe maintenance of normal heart function requires proper control of protein turnover. The ubiquitin-proteasome system is a principal regulator of protein degradation. Mdm2 is the main E3 ubiquitin ligase for p53 in mitotic cells thereby regulating cellular growth, DNA repair, oxidative stress and apoptosis.
View Article and Find Full Text PDFDefining the roadblocks responsible for cell cycle arrest in adult cardiomyocytes lies at the core of developing cardiac regenerative therapies. p53 and Mdm2 are crucial mediators of cell cycle arrest in proliferative cell types, however, little is known about their function in regulating homeostasis and proliferation in terminally differentiated cell types, like cardiomyocytes. To explore this, we generated a cardiac-specific conditional deletion of p53 and Mdm2 (DKO) in adult mice.
View Article and Find Full Text PDFThe tumor suppressor Trp53 (p53) inhibits cell growth after acute stress by regulating gene transcription. The mammalian genome contains hundreds of p53-binding sites. However, whether p53 participates in the regulation of cardiac tissue homeostasis under normal conditions is not known.
View Article and Find Full Text PDFCardiac homeostasis requires proper control of protein turnover. Protein degradation is principally controlled by the Ubiquitin-Proteasome System. Mule is an E3 ubiquitin ligase that regulates cellular growth, DNA repair and apoptosis to maintain normal tissue architecture.
View Article and Find Full Text PDFThe cyclin-dependent kinase inhibitor p21(CIP1/WAF1) (p21) is highly expressed in the adult heart. However, in response to stress, its expression is downregulated. Therefore, we investigated the role of p21 in the regulation of cardiac hypertrophic growth.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2013
Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the ability of an organism to eliminate these toxic intermediates. Although the Parkinson-susceptibility gene, Parkinson protein 7/DJ-1 (DJ-1), has been linked to the regulation of oxidative stress, the exact mechanism by which this occurs and its in vivo relevance have remained elusive. In the heart, oxidative stress is a major contributor to the development of heart failure (HF).
View Article and Find Full Text PDFStatins are widely used clinical drugs that exert beneficial growth-suppressive effects in patients with cardiac hypertrophy. We investigated the role of the cell cycle inhibitor p21(CIP1/WAF1) (p21) in statin-dependent inhibition of hypertrophic growth in postmitotic cardiomyocytes. We demonstrate that lovastatin fails to inhibit cardiac hypertrophy to angiotensin II in p21(-/-) mice and that reconstitution of p21 function by TAT.
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