Chao Cui1, Huang Lin2, Yanyu Shi3, Ruiyan Pan4. 1. Department of Aesthetic Plastic Surgery and Laser Medicine, Beijing Anzhen Hospital, Capital Medical University, Anzhen Road #2, Chaoyang District, Beijing 100029, China. Electronic address: 15501008735@163.com. 2. Department of Aesthetic Plastic Surgery and Laser Medicine, Beijing Anzhen Hospital, Capital Medical University, Anzhen Road #2, Chaoyang District, Beijing 100029, China. Electronic address: linhuang_72@163.com. 3. Department of Aesthetic Plastic Surgery and Laser Medicine, Beijing Anzhen Hospital, Capital Medical University, Anzhen Road #2, Chaoyang District, Beijing 100029, China. Electronic address: 15225928223@163.com. 4. Beijing Institute of Heart Lung and Blood Vessel Diseases, Anzhen Road #2, Chaoyang District, Beijing 100029, China. Electronic address: panruiyan2011@126.com.
Abstract
BACKGROUND: In recent years, many studies have demonstrated that endogenous adenosine induced by ischemia postconditioning reduces apoptosis in animal and cell models, but no study has clearly elucidated the effects of hypoxia postconditioning (HPC) in human dermal microvascular endothelial cells (HDMECs) of flaps, and the subtype of adenosine receptors involved remains unknown. In our study, we sought to identify the roles of adenosine A2a receptor, NDRG3 (N-myc downstream-regulated gene 3) and Raf-ERK pathway in the anti-apoptotic effects of hypoxia postconditioning. METHODS: Human dermal microvascular endothelial cells were put into a hypoxic incubator (94% N2 + 5% CO2 + 1% O2) for 8 h (hypoxia), and followed 24 h of normoxic culture with 95% air and 5% CO2 (reoxygenation). Hypoxia postconditioning model of HDMECs was achieved as follows: Before HDMECs were put into a normoxic incubator, HDMECs were treated by three cycles of 5 min of brief reoxygenation and 5 min of re-hypoxia. Opening level of mitochondrial permeability transition pore and change of mitochondrial membrane potential were detected with related Kit. The protein expressions of mitochondrion apoptosis, adenosine A2a receptor and NDRG3-Raf-ERK pathway were measured by western blot. RESULT: Hypoxia/reoxygenation (H/R) resulted in injury in HDMRCs as evidenced by an increase in apoptosis percentage, mitochondrial membrane permeability and an increase in expression of pro-apoptosis proteins (Bax, c-caspase-3 and cytochrom C), meanwhile, hypoxia/reoxygenation increased expression of A2a receptor, NDRG3, p-c-Raf, p-ERK, which was significantly attenuated by hypoxia postconditioning treatment. Moreover, Hypoxia/reoxygenation (H/R) resulted in a decrease in expression of anti-apoptotic protein (Bcl-2). However, the protective effect of hypoxia postconditioning treatment could be inhibited by adding CGS21680, a selective adenosine A2a receptor agonist (all P values < 0.05).
BACKGROUND: In recent years, many studies have demonstrated that endogenous adenosine induced by ischemia postconditioning reduces apoptosis in animal and cell models, but no study has clearly elucidated the effects of hypoxia postconditioning (HPC) in human dermal microvascular endothelial cells (HDMECs) of flaps, and the subtype of adenosine receptors involved remains unknown. In our study, we sought to identify the roles of adenosine A2a receptor, NDRG3 (N-myc downstream-regulated gene 3) and Raf-ERK pathway in the anti-apoptotic effects of hypoxia postconditioning. METHODS:Human dermal microvascular endothelial cells were put into a hypoxic incubator (94% N2 + 5% CO2 + 1% O2) for 8 h (hypoxia), and followed 24 h of normoxic culture with 95% air and 5% CO2 (reoxygenation). Hypoxia postconditioning model of HDMECs was achieved as follows: Before HDMECs were put into a normoxic incubator, HDMECs were treated by three cycles of 5 min of brief reoxygenation and 5 min of re-hypoxia. Opening level of mitochondrial permeability transition pore and change of mitochondrial membrane potential were detected with related Kit. The protein expressions of mitochondrion apoptosis, adenosine A2a receptor and NDRG3-Raf-ERK pathway were measured by western blot. RESULT: Hypoxia/reoxygenation (H/R) resulted in injury in HDMRCs as evidenced by an increase in apoptosis percentage, mitochondrial membrane permeability and an increase in expression of pro-apoptosis proteins (Bax, c-caspase-3 and cytochrom C), meanwhile, hypoxia/reoxygenation increased expression of A2a receptor, NDRG3, p-c-Raf, p-ERK, which was significantly attenuated by hypoxia postconditioning treatment. Moreover, Hypoxia/reoxygenation (H/R) resulted in a decrease in expression of anti-apoptotic protein (Bcl-2). However, the protective effect of hypoxia postconditioning treatment could be inhibited by adding CGS21680, a selective adenosine A2a receptor agonist (all P values < 0.05).
Authors: Kyung Rok Kim; Kyung A Kim; Joon Sung Park; Jun Young Jang; Yuri Choi; Hyung Ho Lee; Dong Chul Lee; Kyung Chan Park; Young Il Yeom; Hyun-Jung Kim; Byung Woo Han Journal: Biomolecules Date: 2020-01-06