BACKGROUND/AIMS: Inhibition of Drp-1-mediated mitochondrial fission limits reactive oxygen species (ROS) production and apoptosis in cardiomyocytes subjected to ischemia/reperfusion injury. It remains unknown if Dynamin 2 inhibition results in similar protective effects. Here we studied the role of Dynamin 2 in cardiomyocyte oxidative stress-induced apoptosis and ROS production. METHODS: The effect of lentiviral shRNA (lv5-shRNA) mediated Dynamin 2 knockdown on apopotosis, mitochondria, and ROS production were studied in neonatal mouse cardiomycytes, which were further treated with either selective Drp1 inhibitor mdivi-1 or the Dynamin 2/Drp1 inhibitor Dynasore. Apoptosis was evaluated by flow cytometry. Mitochondrial morphology and transmembrane potential (ΔΨm) were studied by confocal microscopy, and ROS production was detected by dichlorofluorescein diacetate. RESULTS: Inhibition of Drp1 and Dynamin 2 protected against mitochondrial fragmentation, maintained ΔΨm, attenuated cellular ROS production and limited apoptosis. Moreover, Lv5-shRNA mediated knockdown of Dynamin 2 alleviated mitochondrial fragmentation, and reduced both ROS production and oxidative stress-induced apoptosis. The protective effects of Dynamin 2 knockdown were enhanced by Dynasore, indicating an added benefit. CONCLUSIONS: Oxidative stress-induced apoptosis and ROS production are attenuated by not only Drp1 inhibition but also Dynamin 2 inhibition, implicating Dynamin 2 as a mediator of oxidative stress in cardiomyocytes.
BACKGROUND/AIMS: Inhibition of Drp-1-mediated mitochondrial fission limits reactive oxygen species (ROS) production and apoptosis in cardiomyocytes subjected to ischemia/reperfusion injury. It remains unknown if Dynamin 2 inhibition results in similar protective effects. Here we studied the role of Dynamin 2 in cardiomyocyte oxidative stress-induced apoptosis and ROS production. METHODS: The effect of lentiviral shRNA (lv5-shRNA) mediated Dynamin 2 knockdown on apopotosis, mitochondria, and ROS production were studied in neonatal mouse cardiomycytes, which were further treated with either selective Drp1 inhibitor mdivi-1 or the Dynamin 2/Drp1 inhibitor Dynasore. Apoptosis was evaluated by flow cytometry. Mitochondrial morphology and transmembrane potential (ΔΨm) were studied by confocal microscopy, and ROS production was detected by dichlorofluorescein diacetate. RESULTS: Inhibition of Drp1 and Dynamin 2 protected against mitochondrial fragmentation, maintained ΔΨm, attenuated cellular ROS production and limited apoptosis. Moreover, Lv5-shRNA mediated knockdown of Dynamin 2 alleviated mitochondrial fragmentation, and reduced both ROS production and oxidative stress-induced apoptosis. The protective effects of Dynamin 2 knockdown were enhanced by Dynasore, indicating an added benefit. CONCLUSIONS:Oxidative stress-induced apoptosis and ROS production are attenuated by not only Drp1 inhibition but also Dynamin 2 inhibition, implicating Dynamin 2 as a mediator of oxidative stress in cardiomyocytes.
Authors: Rebecca J Wilson; Joshua C Drake; Di Cui; Mei Zhang; Heather M Perry; Jennifer A Kashatus; Christine M Kusminski; Philipp E Scherer; David F Kashatus; Mark D Okusa; Zhen Yan Journal: Mitochondrion Date: 2017-12-20 Impact factor: 4.160
Authors: Andrew Webster; Shravan K Chintala; Jasmine Kim; Michelle Ngan; Tatsuo Itakura; Noorjahan Panjwani; Pablo Argüeso; Joseph T Barr; Shinwu Jeong; M Elizabeth Fini Journal: PLoS One Date: 2018-10-10 Impact factor: 3.240