Changes in mitochondrial dynamics during ceramide-induced cardiomyocyte early apoptosis

Citations Over TimeTop 10% of 2007 papers

Abstract

In cells, mitochondria are organized as a network of interconnected organelles that fluctuate between fission and fusion events (mitochondrial dynamics). This process is associated with cell death. We investigated whether activation of apoptosis with ceramides affects mitochondrial dynamics and promotes mitochondrial fission in cardiomyocytes. Neonatal rat cardiomyocytes were incubated with C2-ceramide or the inactive analog dihydro-C2-ceramide for up to 6 h. Three-dimensional images of cells loaded with mitotracker green were obtained by confocal microscopy. Dynamin-related protein-1 (Drp-1) and mitochondrial fission protein 1 (Fis1) distribution and levels were studied by immunofluorescence and western blot. Mitochondrial membrane potential (ΔΨm) and cytochrome c (cyt c) distribution were used as indexes of early activation of apoptosis. Cell viability and DNA fragmentation were determined by propidium iodide staining/flow cytometry, whereas cytotoxicity was evaluated by lactic dehydrogenase activity. To decrease the levels of the mitochondrial fusion protein mitofusin 2, we used an antisense adenovirus (AsMfn2). C2-ceramide, but not dihydro-C2-ceramide, promoted rapid fragmentation of the mitochondrial network in a concentration- and time-dependent manner. C2-ceramide also increased mitochondrial Drp-1 and Fis1 content, Drp-1 colocalization with Fis1, and caused early activation of apoptosis. AsMfn2 accentuated the decrease in ΔΨm and cyt c redistribution induced by C2-ceramide. Doxorubicin, which induces cardiomyopathy and apoptosis through ceramide generation, also stimulated mitochondrial fragmentation. Ceramides stimulate mitochondrial fission and this event is associated with early activation of cardiomyocyte apoptosis.

Related Papers

• → Regulation of plasma ceramide levels with fatty acid oversupply: evidence that the liver detects and secretes de novo synthesised ceramide(2012)111 cited
• → Ceramide generation by two distinct pathways in tumor necrosis factor α‐induced cell death(2001)107 cited
• → Ceramide synthase 4 is highly expressed in involved skin of patients with atopic dermatitis(2016)42 cited
• → Bacterial Infections and Ceramide(2013)31 cited
• → Ceramide Signaling in Apoptosis and Cancer Therapy(2006)