OBJECTIVE: This study aimed to examine the effects of adenovirus-mediated expression of p35, a baculovirus gene, on apoptosis induced by hypoxia/reoxygenation (H/R) in cardiomyocytes. METHODS: Neonatal rat cardiomyocytes were infected with recombinant adenoviral vectors expressing p35 (Ad2/CMVp35) or no transgene (Ad2/CMVEV) and were then subjected to H/R. Separate groups of non-infected cardiomyocytes were treated with pharmacological caspase inhibitors or antioxidants. Cell viability, apoptosis, caspase activity, and cellular reactive oxygen species (ROS) were measured using various assays. RESULTS: H/R decreased cell viability and increased cellular ROS levels, caspase activity, and cell apoptosis. Infection with Ad2/CMVp35 effectively inhibited the increase in cellular ROS levels, the activities of caspases 3 and 8, apoptosis, and cell death following H/R, whereas Ad2/CMVEV had no effect. Despite its ability to abolish the increase in caspase activity and partially inhibit apoptosis, the pan-caspase inhibitor ZVAD-fmk (100 microM) failed to significantly reduce cell death induced by H/R. N-acetyl-L-cysteine, an antioxidant, completely inhibited H/R-induced increase in cellular ROS levels, but reduced apoptosis and cell death by 30% only. CONCLUSIONS: Adenovirus-mediated expression of p35 effectively inhibits H/R-induced cardiomyocyte apoptosis by reducing cellular ROS levels and inhibiting caspase activity.
OBJECTIVE: This study aimed to examine the effects of adenovirus-mediated expression of p35, a baculovirus gene, on apoptosis induced by hypoxia/reoxygenation (H/R) in cardiomyocytes. METHODS: Neonatal rat cardiomyocytes were infected with recombinant adenoviral vectors expressing p35 (Ad2/CMVp35) or no transgene (Ad2/CMVEV) and were then subjected to H/R. Separate groups of non-infected cardiomyocytes were treated with pharmacological caspase inhibitors or antioxidants. Cell viability, apoptosis, caspase activity, and cellular reactive oxygen species (ROS) were measured using various assays. RESULTS: H/R decreased cell viability and increased cellular ROS levels, caspase activity, and cell apoptosis. Infection with Ad2/CMVp35 effectively inhibited the increase in cellular ROS levels, the activities of caspases 3 and 8, apoptosis, and cell death following H/R, whereas Ad2/CMVEV had no effect. Despite its ability to abolish the increase in caspase activity and partially inhibit apoptosis, the pan-caspase inhibitor ZVAD-fmk (100 microM) failed to significantly reduce cell death induced by H/R. N-acetyl-L-cysteine, an antioxidant, completely inhibited H/R-induced increase in cellular ROS levels, but reduced apoptosis and cell death by 30% only. CONCLUSIONS: Adenovirus-mediated expression of p35 effectively inhibits H/R-induced cardiomyocyte apoptosis by reducing cellular ROS levels and inhibiting caspase activity.
Authors: Merry L Lindsey; Roberto Bolli; John M Canty; Xiao-Jun Du; Nikolaos G Frangogiannis; Stefan Frantz; Robert G Gourdie; Jeffrey W Holmes; Steven P Jones; Robert A Kloner; David J Lefer; Ronglih Liao; Elizabeth Murphy; Peipei Ping; Karin Przyklenk; Fabio A Recchia; Lisa Schwartz Longacre; Crystal M Ripplinger; Jennifer E Van Eyk; Gerd Heusch Journal: Am J Physiol Heart Circ Physiol Date: 2018-01-12 Impact factor: 4.733