Rong Li1, Li-Zhao Wang2, Jun-Hui Du3, Lei Zhao4, Yang Yao5. 1. Department of Ophthalmology, the First Affiliated Hospital of Xi'an Medical University, Xi'an 710077, Shaanxi Province, China. 2. Department of Cataract, Xi'an aier eye hospital, Xi'an 710061, Shaanxi Province, China. 3. Department of Ophthalmology, Xi'an Ninth Hospital Affiliated to Medical College of Xi'an Jiaotong University, Xi'an 710054, Shaanxi Province, China. 4. Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA. 5. Department of Central laboratory, the First Affiliated Hospital of Xi'an Medical University, Xi'an 710077, Shaanxi Province, China.
Abstract
AIM: To explore the state of autophagy and related mechanisms in the murine retinal microvascular endothelial cells (RMECs) under hypoxia stimulation. METHODS: The murine RMECs were primarily cultured and randomly divided into three groups: hypoxia group (cultured in 1% O2 environment), hypoxia+autophagy inhibition group [pretreated with 5 mmol/L 3-methyladenine (3-MA) for 4h followed by incubation in 1% O2] and control group (cultured under normoxic condition). The state of autophagy in RMECs was examined by assaying the turnover of light chain 3B (LC3BB) and expression of Beclin-1, Atg3 and Atg5 proteins with Western blotting, by detecting formation of autophagosomes with transmission electron microscopy (TEM) and by counting the number of GFP+ puncta in RMECs. The protein levels of AMPK, P-AMPK, Akt, P-Akt, m-TOR and P-mTOR were also assayed by Western blotting. RESULTS: Primary murine RMECs were successfully cultured. Under hypoxic conditions, the ratio of LC3BB-II/I and the expression of Beclin-1, Atg3 and Atg5 proteins were increased when compared with the control group. In addition, the numbers of autophagosome and the GFP+ puncta were also increased under hypoxia. However, pre-treatment with 3-MA obviously attenuated these changes in autophagy in RMECs under hypoxia. Protein expression of P-Akt and P-AMPK was increased but P-mTOR level was decreased in cells exposed to hypoxia. CONCLUSION: In murine RMECs autophagy is activated under hypoxia possibly through activation of the AMPK/mTOR signaling pathway.
AIM: To explore the state of autophagy and related mechanisms in the murine retinal microvascular endothelial cells (RMECs) under hypoxia stimulation. METHODS: The murine RMECs were primarily cultured and randomly divided into three groups: hypoxia group (cultured in 1% O2 environment), hypoxia+autophagy inhibition group [pretreated with 5 mmol/L 3-methyladenine (3-MA) for 4h followed by incubation in 1% O2] and control group (cultured under normoxic condition). The state of autophagy in RMECs was examined by assaying the turnover of light chain 3B (LC3BB) and expression of Beclin-1, Atg3 and Atg5 proteins with Western blotting, by detecting formation of autophagosomes with transmission electron microscopy (TEM) and by counting the number of GFP+ puncta in RMECs. The protein levels of AMPK, P-AMPK, Akt, P-Akt, m-TOR and P-mTOR were also assayed by Western blotting. RESULTS: Primary murine RMECs were successfully cultured. Under hypoxic conditions, the ratio of LC3BB-II/I and the expression of Beclin-1, Atg3 and Atg5 proteins were increased when compared with the control group. In addition, the numbers of autophagosome and the GFP+ puncta were also increased under hypoxia. However, pre-treatment with 3-MA obviously attenuated these changes in autophagy in RMECs under hypoxia. Protein expression of P-Akt and P-AMPK was increased but P-mTOR level was decreased in cells exposed to hypoxia. CONCLUSION: In murine RMECs autophagy is activated under hypoxia possibly through activation of the AMPK/mTOR signaling pathway.
Authors: David O Zamora; Michael Riviere; Dongseok Choi; Yuzhen Pan; Stephen R Planck; James T Rosenbaum; Larry L David; Justine R Smith Journal: Mol Vis Date: 2007-10-30 Impact factor: 2.367
Authors: Marisa Granato; Roberta Santarelli; Mariarosaria Filardi; Roberta Gonnella; Antonella Farina; Maria Rosaria Torrisi; Alberto Faggioni; Mara Cirone Journal: Autophagy Date: 2015-11-02 Impact factor: 16.016