Pathological cardiac hypertrophy is a major risk factor associated with heart failure, a state concomitant with increased cell death. However, the mechanism governing progression of hypertrophy to apoptosis at the single-cell level remains elusive. Here, we demonstrate annexin A6 (Anxa6), a calcium (Ca(2+))-dependent phospholipid-binding protein critically regulates the transition of chronic hypertrophied cardiomyocytes to apoptosis. Treatment of the H9c2(2-1) cardiomyocytes with hypertrophic agonists upregulates and relocalizes Anxa6 with increased cytosolic punctate appearance. Live cell imaging revealed that chronic exposure to hypertrophic agonists such as phenylephrine (PE) compromises the mitochondrial membrane potential (ΔΨm) and morphological dynamics. Such chronic hypertrophic induction also activated the caspases 9 and 3 and induced cleavage of the poly-(ADP-ribose) polymerase 1 (Parp1), which are the typical downstream events in the mitochondrial pathways of apoptosis. An increased rate of apoptosis was evident in the hypertrophied cardiomyocytes after 48-72 h of treatment with the hypertrophic agonists. Anxa6 was progressively associated with the mitochondrial fraction under chronic hypertrophic stimulation, and Anxa6 knockdown severely abrogated mitochondrial network and dynamics. Ectopically expressed Anxa6 protected the mitochondrial morphology and dynamics under PE treatment, and also increased the cellular susceptibility to apoptosis. Biochemical analysis showed that Anxa6 interacts with Parp1 and its 89 kDa cleaved product in a Ca(2+)-dependent manner through the N-terminal residues (1-28). Furthermore, expression of Anxa6(S13E), a mutant dominant negative with respect to Parp1 binding, served as an enhancer of mitochondrial dynamics, even under chronic PE treatment. Chemical inhibition of Parp1 activity released the cellular vulnerability to apoptosis in Anxa6-expressing stable cell lines, thereby shifting the equilibrium away from cell death. Taken together, the present study depicts a dual regulatory function of Anxa6 that is crucial for balancing hypertrophy with apoptosis in cardiomyocytes.
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http://dx.doi.org/10.1038/cddis.2015.231 | DOI Listing |
Biomedicines
January 2025
Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil.
: Aging is associated with structural and functional changes in the heart, including hypertrophy, fibrosis, and impaired contractility. Cellular mechanisms such as senescence, telomere shortening, and DNA damage contribute to these processes. Nuclear factor kappa B (NF-κB) has been implicated in mediating cellular responses in aging tissues, and increased NF-κB expression has been observed in the hearts of aging rodents.
View Article and Find Full Text PDFAntioxidants (Basel)
January 2025
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain.
Arterial hypertension has a high prevalence in the population and is considered both a cardiovascular disease and an important risk factor for the development of other cardiovascular diseases. Tea consumption shows antihypertensive effects due to its composition in terms of bioactive substances such as flavan-3-ols and xanthines. The aim of this study was to assess the possible beneficial effects of two tea extracts, one of white tea (ADM White Tea; WTE) and another one composed of a mixture of black tea and green tea (ADM Tea Complex; CTE), on the cardiovascular alterations induced by angiotensin II (AngII) infusion in mice.
View Article and Find Full Text PDFBiol Open
January 2025
Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Manipal 576104, India.
Chromosomal aneuploidies are a major cause of developmental failure and pregnancy loss. To investigate the possible consequences of aneuploidy on early embryonic development in vitro, we focused on primed pluripotent stem cells that are relatable to the epiblast of post-implantation embryos in vivo. We used human induced pluripotent stem cells (iPSCs) as an epiblast model and altered chromosome numbers by treating with reversine, a small-molecule inhibitor of monopolar spindle 1 kinase (MSP1) that inactivates the spindle assembly checkpoint, which has been strongly implicated in chromosome mis-segregation and aneuploidy generation.
View Article and Find Full Text PDFFood Sci Nutr
January 2025
Faculty of Chemical and Food Engineering, Bahir Dar Institute of Technology Bahir Dar University Bahir Dar Ethiopia.
Luteolin is widely distributed phytochemical, a flavonoid, in kingdom plantae. Luteolin with potential antioxidant activity prevent ROS-induced damages and reduce oxidative stress which is mainly responsible in pathogenesis of many diseases. Several chemo preventive activities and therapeutic benefits are associated with luteolin.
View Article and Find Full Text PDFJ Pharmacol Sci
February 2025
Department of Pharmacology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Tokushima, Japan. Electronic address:
Background: The global increase in diabetes, driven by aging populations and lifestyle changes, has led to an increase in the incidence of diabetic cardiomyopathy (DCM). DCM is characterized by metabolic abnormalities, oxidative stress, and inflammation, leading to cardiac remodeling and dysfunction. Goreisan (GRS), a traditional Japanese Kampo medicine, is commonly used to treat fluid control such as edema, due to its diuretic effect.
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