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Zhao X, Liu F, Jin H, Li R, Wang Y, Zhang W, Wang H, Chen W. Involvement of PKCα and ERK1/2 signaling pathways in EGCG's protection against stress-induced neural injuries in Wistar rats. Neuroscience 2017; 346:226-237. [PMID: 28131624 DOI: 10.1016/j.neuroscience.2017.01.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/12/2017] [Accepted: 01/14/2017] [Indexed: 02/08/2023]
Abstract
Stress-induced neural injuries are closely linked to the pathogenesis of various neuropsychiatric disorders and psychosomatic diseases. We and others have previously demonstrated certain protective effects of epigallocatechin-3-gallate (EGCG) in stress-induced cerebral impairments, but the underlying protective mechanisms still remain poorly elucidated. Here we provide evidence to support the possible involvement of PKCα and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways in EGCG-mediated protection against restraint stress-induced neural injuries in rats. In both open-field and step-through behavioral tests, the restraint stress-induced neuronal impairments were significantly ameliorated by administration of EGCG or green tea polyphenols (GTPs), which was associated with a partial restoration of normal plasma glucocorticoid, dopamine and serotonin levels. Furthermore, the stress-induced decrease of PKCα and ERK1/2 expression and phosphorylation was significantly attenuated by EGCG and to a less extent by GTP administration. Additionally, EGCG supplementation restored the production of adenosine triphosphate (ATP) and the expression of a key regulator of cellular energy metabolism, the peroxisome proliferators-activated receptor-γ coactivator-1α (PGC-1α), in stressed animals. In conclusion, PKCα and ERK1/2 signaling pathways as well as PGC-1α-mediated ATP production might be involved in EGCG-mediated protection against stress-induced neural injuries.
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Affiliation(s)
- Xiaoling Zhao
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Fengqin Liu
- Weifang People's Hospital, Weifang, Shandong Province, China
| | - Haimin Jin
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China; Tianjin Medical University, Tianjin, China
| | - Renjia Li
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China; Tianjin Medical University, Tianjin, China
| | - Yonghui Wang
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | | | - Haichao Wang
- The Feinstein Institute for Medical Research, Manhasset, NY, USA; Department of Emergency Medicine, North Shore University Hospital, Manhasset, NY, USA.
| | - Weiqiang Chen
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China; The Feinstein Institute for Medical Research, Manhasset, NY, USA.
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Wang X, Ma Z, Fu Z, Gao S, Yang L, Jin Y, Sun H, Wang C, Fan W, Chen L, Zheng QY, Bi G, Ma CL. Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs. ASN Neuro 2016; 8:8/2/1759091416642345. [PMID: 27067428 PMCID: PMC4828664 DOI: 10.1177/1759091416642345] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 12/30/2015] [Indexed: 11/15/2022] Open
Abstract
Excessive glutamate release causes overactivation of N-methyl d-aspartate receptors (NMDARs), leading to excitatory neuronal damage in cerebral ischemia. Hydroxysafflor yellow A (HSYA), a compound extracted from Carthamus tinctorius L., has been reported to exert a neuroprotective effect in many pathological conditions, including brain ischemia. However, the underlying mechanism of HSYA's effect on neurons remains elusive. In the present study, we conducted experiments using patch-clamp recording of mouse hippocampal slices. In addition, we performed Ca2+ imaging, Western blots, as well as mitochondrial-targeted circularly permuted yellow fluorescent protein transfection into cultured hippocampal neurons in order to decipher the physiological mechanism underlying HSYA's neuroprotective effect. Through the electrophysiology experiments, we found that HSYA inhibited NMDAR-mediated excitatory postsynaptic currents without affecting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and γ-aminobutyric acid A-type receptor-mediated currents. This inhibitory effect of HSYA on NMDARs was concentration dependent. HSYA did not show any preferential inhibition of either N-methyl d-aspartate receptor subtype 2A- or N-methyl d-aspartate receptor subtype 2B- subunit-containing NMDARs. Additionally, HSYA exhibits a facilitatory effect on paired NMDAR-mediated excitatory postsynaptic currents. Furthermore, HSYA reduced the magnitude of NMDAR-mediated membrane depolarization currents evoked by oxygen-glucose deprivation, and suppressed oxygen-glucose deprivation–induced and NMDAR-dependent ischemic long-term potentiation, which is believed to cause severe reperfusion damage after ischemia. Through the molecular biology experiments, we found that HSYA inhibited the NMDA-induced and NMDAR-mediated intracellular Ca2+ concentration increase in hippocampal cultures, reduced apoptotic and necrotic cell deaths, and prevented mitochondrial damage. Together, our data demonstrate for the first time that HSYA protects hippocampal neurons from excitotoxic damage through the inhibition of NMDARs. This novel finding indicates that HSYA may be a promising pharmacological candidate for the treatment of brain ischemia.
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Affiliation(s)
- Xingtao Wang
- Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Zhiyuan Ma
- School of Public Economics and Administration, Shanghai University of Finance and Economics, Shanghai, China
| | - Zhongxiao Fu
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Su Gao
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Liu Yang
- Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China
| | - Yan Jin
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Hui Sun
- Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China
| | - Chaoyun Wang
- Department of Pharmacology, Binzhou Medical University, Yantai, Shandong, China
| | - Weiming Fan
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Lin Chen
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Qing-Yin Zheng
- Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China
| | - Guoqiang Bi
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Chun-Lei Ma
- Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China
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