TY - JOUR
T1 - Mitochondrial fission in endothelial cells after simulated ischemia/reperfusion
T2 - Role of nitric oxide and reactive oxygen species
AU - Giedt, Randy J.
AU - Yang, Changjun
AU - Zweier, Jay L.
AU - Matzavinos, Anastasios
AU - Alevriadou, B. Rita
PY - 2012/1/15
Y1 - 2012/1/15
N2 - Ischemia (I)/reperfusion (RP)-induced endothelial cell (EC) injury is thought to be due to mitochondrial reactive oxygen species (mtROS) production. MtROS have been implicated in mitochondrial fission. We determined whether cultured EC exposure to simulated I/RP causes morphological changes in the mitochondrial network and the mechanisms behind those changes. Because shear stress results in nitric oxide (NO)-mediated endothelial mtROS generation, we simulated I/RP as hypoxia (H) followed by oxygenated flow over the ECs (shear stress of 10 dyn/cm 2). By exposing ECs to shear stress, H, H/reoxygenation (RO), or simulated I/RP and employing MitoTracker staining, we assessed the differential effects of changes in mechanical forces and/or O 2 levels on the mitochondrial network. Static or sheared ECs maintained their mitochondrial network. H- or H/RO-exposed ECs underwent changes, but mitochondrial fission was significantly less compared to that in ECs exposed to I/RP. I/RP-induced fission was partially inhibited by antioxidants, a NO synthase inhibitor, or an inhibitor of the fission protein dynamin-related protein 1 (Drp1) and was accompanied by Drp1 oligomerization and phosphorylation (Ser616). Hence, shear-induced NO, ROS (including mtROS), and Drp1 activation are responsible for mitochondrial fission in I/RP-exposed ECs, and excessive fission may be an underlying cause of EC dysfunction in postischemic hearts.
AB - Ischemia (I)/reperfusion (RP)-induced endothelial cell (EC) injury is thought to be due to mitochondrial reactive oxygen species (mtROS) production. MtROS have been implicated in mitochondrial fission. We determined whether cultured EC exposure to simulated I/RP causes morphological changes in the mitochondrial network and the mechanisms behind those changes. Because shear stress results in nitric oxide (NO)-mediated endothelial mtROS generation, we simulated I/RP as hypoxia (H) followed by oxygenated flow over the ECs (shear stress of 10 dyn/cm 2). By exposing ECs to shear stress, H, H/reoxygenation (RO), or simulated I/RP and employing MitoTracker staining, we assessed the differential effects of changes in mechanical forces and/or O 2 levels on the mitochondrial network. Static or sheared ECs maintained their mitochondrial network. H- or H/RO-exposed ECs underwent changes, but mitochondrial fission was significantly less compared to that in ECs exposed to I/RP. I/RP-induced fission was partially inhibited by antioxidants, a NO synthase inhibitor, or an inhibitor of the fission protein dynamin-related protein 1 (Drp1) and was accompanied by Drp1 oligomerization and phosphorylation (Ser616). Hence, shear-induced NO, ROS (including mtROS), and Drp1 activation are responsible for mitochondrial fission in I/RP-exposed ECs, and excessive fission may be an underlying cause of EC dysfunction in postischemic hearts.
KW - Dynamin-related protein 1
KW - Endothelial cell
KW - Free radicals
KW - Hypoxia/reoxygenation
KW - Ischemia/reperfusion
KW - Mitochondrial fission
KW - Mitochondrial superoxide
KW - Nitric oxide
KW - Shear stress
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U2 - 10.1016/j.freeradbiomed.2011.10.491
DO - 10.1016/j.freeradbiomed.2011.10.491
M3 - Article
C2 - 22100972
AN - SCOPUS:84855462583
SN - 0891-5849
VL - 52
SP - 348
EP - 356
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 2
ER -