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Zhang Q, Yin J, Xu F, Zhai J, Yin J, Ge M, Zhou W, Li N, Qin X, Li Y, Wang S. Isoflurane post-conditioning contributes to anti-apoptotic effect after cerebral ischaemia in rats through the ERK5/MEF2D signaling pathway. J Cell Mol Med 2021; 25:3803-3815. [PMID: 33621420 PMCID: PMC8051747 DOI: 10.1111/jcmm.16282] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/13/2020] [Accepted: 01/04/2021] [Indexed: 01/14/2023] Open
Abstract
The mechanisms of brain protection during ischaemic reperfusion injury induced by isoflurane (ISO) post‐conditioning are unclear. Myocyte enhancement factor 2 (MEF2D) has been shown to promote neural survival in a variety of models, in which multiple survival and death signals converge on MEF2D and modulate its activity. Here, we investigated the effect of MEF2D on the neuroprotective effects of ISO post‐conditioning on rats after cerebral ischaemia/reperfusion (I/R) injury. Rats underwent middle cerebral artery occlusion (MCAO) surgery with ischaemia for 90 minutes and reperfusion for 24‐48 hours. After MCAO, neurological status was assessed at 12, 24 and 48 hours by the Modified Neurological Severity Score (mNSS) test. The passive avoidance test (PAT) was used to assess cognition function. Histological and neuropathological evaluations were performed with HE staining and Nissl's staining, respectively. We measured the expression of MEF2D, ERK5, GFAP and caspase‐3 by immunofluorescent staining and Western blotting, and TUNEL staining to assess the severity of apoptosis in hippocampal CA1 area. We found that MEF2D was involved in nerve protection after I/R injury, and post‐treatment of ISO significantly promoted the phosphorylation of ERK5, increased MEF2D transcriptional activity, inhibited the expression of caspase‐3 and played a role of brain protection.
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Affiliation(s)
- Qingtong Zhang
- Department of Anesthesiology, Lu'an Hospital Affiliated to Anhui Medical University, Lu'an People's Hospital, Lu'an, China
| | - Jiangwen Yin
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Feng Xu
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Jingwen Zhai
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Jieting Yin
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Mingyue Ge
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Wenyi Zhou
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Nian Li
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Xinlei Qin
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Yan Li
- Department of Anesthesiology, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Sheng Wang
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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2
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Wang N, Yang W, Li L, Tian M. MEF2D upregulation protects neurons from oxygen-glucose deprivation/re-oxygenation-induced injury by enhancing Nrf2 activation. Brain Res 2020; 1741:146878. [PMID: 32407713 DOI: 10.1016/j.brainres.2020.146878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 04/16/2020] [Accepted: 05/06/2020] [Indexed: 12/16/2022]
Abstract
Accumulating evidence suggests that myocyte enhancer factor 2D (MEF2D) is a pro-survival factor for neurons. However, whether MEF2D is involved in protecting neurons from cerebral ischemia/reperfusion injury remains unknown. The current study was designed to investigate the exact role and mechanism of MEF2D in regulating oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced neuronal injury, an in vitro model used to study cerebral ischemia/reperfusion injury. MEF2D expression was significantly induced in neurons in response to OGD/R injury. Functional analysis demonstrated that MEF2D upregulation significantly rescued the decreased viability of OGD/R-injured neurons and suppressed OGD/R-induced apoptosis and reactive oxygen species (ROS) production. By contrast, MEF2D knockdown increased the sensitivity of neurons to OGD/R-induced injury. Moreover, MEF2D overexpression increased the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and enhanced the activation of Nrf2 antioxidant signaling. However, Nrf2 knockdown partially blocked the MEF2D-mediated neuroprotective effect in OGD/R-exposed neurons. Overall, these results reveal that MEF2D overexpression attenuates OGD/R-induced injury by enhancing Nrf2-mediated antioxidant signaling. These findings suggest that MEF2D may serve as a neuroprotective target with a potential application for treatment of cerebral ischemia/reperfusion injury.
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Affiliation(s)
- Nan Wang
- Department of Anesthesiology, Xi'an Ninth Hospital, Xi'an, Shaanxi 710054, China
| | - Weiwei Yang
- Department of Anesthesiology, Xi'an Ninth Hospital, Xi'an, Shaanxi 710054, China
| | - Lan Li
- Department of Anesthesiology, Xi'an Ninth Hospital, Xi'an, Shaanxi 710054, China
| | - Ming Tian
- Department of Anesthesiology, Xi'an Ninth Hospital, Xi'an, Shaanxi 710054, China.
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3
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Li T, Zhang W, Kang X, Yang R, Li R, Huang L, Chen J, Yang Q, Sun X. Salidroside protects dopaminergic neurons by regulating the mitochondrial MEF2D‐ND6 pathway in the MPTP/MPP
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‐induced model of Parkinson's disease. J Neurochem 2019; 153:276-289. [PMID: 31520529 DOI: 10.1111/jnc.14868] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 08/07/2019] [Accepted: 08/28/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Tao Li
- Research Center of Traditional Chinese Medicine Xijing Hospital Fourth Military Medical University Xi'an China
| | - Wei Zhang
- Research Center of Traditional Chinese Medicine Xijing Hospital Fourth Military Medical University Xi'an China
| | - Xiaogang Kang
- Department of Neurology Xijing Hospital Fourth Military Medical University Xi’an China
| | - Ruixin Yang
- Department of Neurosurgery Tangdu Hospital Fourth Military Medical University Xi'an China
| | - Ruru Li
- Research Center of Traditional Chinese Medicine Xijing Hospital Fourth Military Medical University Xi'an China
| | - Lu Huang
- Department of Neurosurgery Tangdu Hospital Fourth Military Medical University Xi'an China
| | - Jianzong Chen
- Research Center of Traditional Chinese Medicine Xijing Hospital Fourth Military Medical University Xi'an China
| | - Qian Yang
- Department of Neurosurgery Tangdu Hospital Fourth Military Medical University Xi'an China
| | - Xiaolong Sun
- Department of Rehabilitation Medicine Xijing Hospital Fourth Military Medical University Xi'an China
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4
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Carvacrol Protects Against 6-Hydroxydopamine-Induced Neurotoxicity in In Vivo and In Vitro Models of Parkinson's Disease. Neurotox Res 2019; 37:156-170. [PMID: 31364033 DOI: 10.1007/s12640-019-00088-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/23/2019] [Accepted: 07/09/2019] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative movement disorder characterized by selective loss of dopaminergic neurons that project from the substantia nigra pars compacta to the striatum. Evidence from human and animal studies has suggested that oxidative damage critically contributes to neuronal loss in PD. Carvacrol (CAR), a monoterpenic phenol, is the main constituents in the essential oil of many aromatic plants and possesses some properties including anti-inflammatory and anti-oxidant effects. In this study, in vitro and in vivo experiments were performed with the CAR in order to investigate its potential neuroprotective effects in models of PD. Post-treatment with CAR in vitro was found to protect rat adrenal pheochromocytoma PC12 cells from toxicity induced by 6-hydroxydopamine (6-OHDA) administration in a dose-dependent manner by (1) increasing cell viability and (2) reduction in intracellular reactive oxygen species, intracellular lipid peroxidation, and annexin-positive cells. In vivo, post-treatment with CAR (15 and 20 mg/kg) was protective against neurodegenerative phenotypes associated with systemic administration of 6-OHDA. Results indicated that CAR improved the locomotor activity, catalepsy, akinesia, bradykinesia, and motor coordination and reduced the apomorphine-caused rotation in 6-OHDA-stimulated rats. Increased level of reduced glutathione content and a decreased level of MDA (malondialdehyde) were observed in the 6-OHDA rats post-treated with CAR. These findings suggest that CAR exerts protective effects, possibly related to an anti-oxidation mechanism, in these in vitro and in vivo models of Parkinson's disease.
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Xu H, Li J, Wang Z, Feng M, Shen Y, Cao S, Li T, Peng Y, Fan L, Chen J, Gu C, Yan F, Wang L, Chen G. Methylene blue attenuates neuroinflammation after subarachnoid hemorrhage in rats through the Akt/GSK-3β/MEF2D signaling pathway. Brain Behav Immun 2017; 65:125-139. [PMID: 28457811 DOI: 10.1016/j.bbi.2017.04.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/14/2017] [Accepted: 04/25/2017] [Indexed: 12/12/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is a serious medical problem with few effective pharmacotherapies available, and neuroinflammation has been identified as an important pathological process in early brain injury (EBI) after SAH. Methylene blue (MB) is an older drug that has been recently proven to exert extraordinary neuroprotective effects in several brain insults. However, no study has reported the beneficial effects of MB in SAH. In the current investigation, we studied the neuroprotective effects of MB in EBI after SAH and focused on its anti-inflammatory role. A total of 303 rats were subjected to an endovascular perforation process to produce an SAH model. We found that MB could significantly ameliorate brain edema secondary to BBB disruption and alleviate neurological dysfunction after SAH. MB administration also promoted the phosphorylation of Akt and GSK-3β, leading to an increased concentration of MEF2D in the nucleus. The cytokine IL-10 was up-regulated, and IL-1β, IL-6 and TNF-α were down-regulated after MB administration. MB administration could also alleviate neutrophil infiltration and microglia activation after SAH. MK2206, a selective inhibitor of Akt, abolished the neuroprotective effects of MB, inhibited the phosphorylation of Akt and prevented the nuclear localization of MEF2D. MK2206 also reduced the expression of IL-10 and increased the expression of pro-inflammatory cytokines. In conclusion, these data suggested that MB could ameliorate neuroinflammatory responses after SAH, and its anti-inflammatory effects might be exerted via activation of the Akt/GSK-3β/MEF2D pathway.
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Affiliation(s)
- Hangzhe Xu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Jianru Li
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Zhijiang Wang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Majing Feng
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China; Department of Neurosurgery, Changxing People's Hospital, Taihuzhong Road 66th, Changxin, Huzhou 313100, China
| | - Yongfeng Shen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China; Department of Neurosurgery, Hangzhou First People's Hospital, Huansha Road 261st, Hangzhou 310006, China
| | - Shenglong Cao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Tao Li
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Yucong Peng
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Linfeng Fan
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Jingyin Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Chi Gu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Feng Yan
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Lin Wang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China
| | - Gao Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou 310016, China.
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Wang R, Yang S, Nie T, Zhu G, Feng D, Yang Q. Transcription Factors: Potential Cell Death Markers in Parkinson's Disease. Neurosci Bull 2017; 33:552-560. [PMID: 28791585 DOI: 10.1007/s12264-017-0168-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 05/07/2017] [Indexed: 12/16/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease with a long preclinical phase. The continuous loss of dopaminergic (DA) neurons is one of the pathogenic hallmarks of PD. Diagnosis largely depends on clinical observation, but motor dysfunctions do not emerge until 70%-80% of the nigrostriatal nerve terminals have been destroyed. Therefore, a biomarker that indicates the degeneration of DA neurons is urgently needed. Transcription factors are sequence-specific DNA-binding proteins that regulate RNA synthesis from a DNA template. The precise control of gene expression plays a critical role in the development, maintenance, and survival of cells, including DA neurons. Deficiency of certain transcription factors has been associated with DA neuron loss and PD. In this review, we focus on some transcription factors and discuss their structure, function, mechanisms of neuroprotection, and their potential for use as biomarkers indicating the degeneration of DA neurons.
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Affiliation(s)
- Ronglin Wang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Shaosong Yang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Tiejian Nie
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Gang Zhu
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Dayun Feng
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Qian Yang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.
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7
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Li GJ, Zhao GQ, Yang JP, Zhou YC, Yang KY, Lei YJ, Huang YC. Effect of miR-1244 on cisplatin-treated non-small cell lung cancer via MEF2D expression. Oncol Rep 2017; 37:3475-3483. [PMID: 28498474 DOI: 10.3892/or.2017.5624] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 08/06/2016] [Indexed: 11/06/2022] Open
Abstract
The aim of this study was to investigate the function of miR-1244 in cisplatin-treated non-small cell lung cancer (NSCLC). The results of quantitative PCR analysis revealed that the expression levels of miR-1244 in cisplatin‑treated A549 and NCI-H522 human lung cancer cell lines were lower than those in untreated A549 and NCI-H522 cells. Similarly, the expression level of miR-1244 in NSCLC tissue samples from cisplatin-treated patients was also lower than that in non-cisplatin-treated NSCLC patients. Notably, the overall survival times of cisplatin-treated NSCLC patients with high miR-1244 expression were superior to those patients with low miR-1244 expression. We found that overexpression of miR-1244 suppressed cell viability and increased LDH toxicity in cisplatin-treated A549 and NCI-H522 cells. Additionally, overexpression of miR-1244 induced the apoptosis of cisplatin-treated A549 and NCI-H522 cells. Furthermore, overexpression of miR-1244 promoted caspase-3 activity and p53 and Bax protein expression, and suppressed myocyte enhancer factor 2D (MEF2D) and cyclin D1 protein expression in cisplatin‑treated A549 and NCI-H522 cells. Small interfering RNA (siRNA) targeting MEF2D suppressed the protein expression of MEF2D, and was able to decrease the proliferation, promote caspase-3 activity, p53 and Bax protein expression and inhibit cyclin D1 protein expression in cisplatin-treated A549 and NCI-H522 cells following the overexpression of miR-1244. In summary, we found that miR-1244 affected cisplatin-treated NSCLC via MEF2D expression.
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Affiliation(s)
- Guang-Jian Li
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Guang-Qiang Zhao
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Jia-Peng Yang
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Yong-Chun Zhou
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Kai-Yun Yang
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Yu-Jie Lei
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Yun-Chao Huang
- Department of Thoracic Surgery, Tumor Hospital of Yunnan Province, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
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8
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Huang L, Deng M, He Y, Lu S, Liu S, Fang Y. β-asarone increases MEF2D and TH levels and reduces α-synuclein level in 6-OHDA-induced rats via regulating the HSP70/MAPK/MEF2D/Beclin-1 pathway: Chaperone-mediated autophagy activation, macroautophagy inhibition and HSP70 up-expression. Behav Brain Res 2016; 313:370-379. [DOI: 10.1016/j.bbr.2016.07.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 07/13/2016] [Accepted: 07/17/2016] [Indexed: 12/31/2022]
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Tseng WT, Hsu YW, Pan TM. Dimerumic Acid and Deferricoprogen Activate Ak Mouse Strain Thymoma/Heme Oxygenase-1 Pathways and Prevent Apoptotic Cell Death in 6-Hydroxydopamine-Induced SH-SY5Y Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:5995-6002. [PMID: 27431098 DOI: 10.1021/acs.jafc.6b01551] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder, which can be modeled using the neurotoxin 6-hydroxydopamine (6-OHDA) to generate oxidative stress. Here, we studied the effects of the antioxidants deferricoprogen (DFC) and dimerumic acid (DMA), produced by rice fermented with Monascus purpureus NTU 568, on 6-OHDA-induced apoptosis in SH-SY5Y cells and their potential protective mechanisms. DMA and DFC inhibited 6-OHDA-induced apoptosis and cellular reactive oxygen species (ROS) in SH-SY5Y human neuroblastoma cells. Molecular analysis demonstrated associated upregulation of the Ak mouse strain thymoma (Akt), heme oxygenase-1 (HO-1), and signal-regulated kinase (ERK) pathways along with inhibited phosphorylation of c-Jun N-terminal kinase (JNK) and p38 pathways and altered homodimeric glycoprotein, N-methyl-d-aspartate (NMDA) receptor, and immunoglobulin Fc receptor gene expression. These results suggested that the neuroprotection elicited by DMA and DFC against 6-OHDA-induced neurotoxicity was associated with the Akt, MAPK, and HO-1 pathways via regulating the gene expression of NMDA receptor, homodimeric glycoprotein, and immunoglobulin Fc receptor.
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Affiliation(s)
- Wei-Ting Tseng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ya-Wen Hsu
- SunWay Biotechnology Company , No. 139, Xing'ai Road, Taipei 11494, Taiwan
| | - Tzu-Ming Pan
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
- SunWay Biotechnology Company , No. 139, Xing'ai Road, Taipei 11494, Taiwan
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10
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Chen ZW, Liu A, Liu Q, Chen J, Li WM, Chao XJ, Yang Q, Liu PQ, Mao ZX, Pi RB. MEF2D Mediates the Neuroprotective Effect of Methylene Blue Against Glutamate-Induced Oxidative Damage in HT22 Hippocampal Cells. Mol Neurobiol 2016; 54:2209-2222. [PMID: 26941101 DOI: 10.1007/s12035-016-9818-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/24/2016] [Indexed: 12/15/2022]
Abstract
Methylene blue (MB) can ameliorate behavioral, neurochemical, and neuropathological impairments in animal models of acute and chronic neurodegenerative disorders, but the underlying mechanism remains unclear. Myocyte enhancer factor 2 (MEF2D) is known to promote neuronal survival in several models, and several survival and death signals converge on MEF2D and regulate its activity. Here, we investigated the role of MEF2D in the neuroprotective effect of MB against glutamate-induced toxicity in HT22 neuronal cells. Our results showed that MB, event at less than 100 nM, improved the viability of HT22 cells exposed to 2 mM glutamate. MB attenuated the mitochondrial impairment and quenches the reactive oxygen species (ROS) induced by glutamate. Surprisingly, MB at 50-200 nM did not affect the Nrf2/HO-1 pathway, an important endogenous anti-oxidative system. Further study showed that MB increased the transcription and translation of MEF2D. In addition, MB upregulated the expression of mitochondrial NADH dehydrogenase 6 (ND6) in a MEF2D-dependent manner. Knockdown of MEF2D abolished both MB-medicated increase of ND6 and MB-induced neuroprotection against glutamate-induced toxicity. Moreover, we showed that MB promoted Akt function activity, suppressed GSK-3β activity, and increased MEF2D level in hippocampus of mice and HT22 cells. These findings for the first time demonstrate that MB protects HT22 neuronal cells against glutamate-induced cell death partially via the regulation of MEF2D-associated survival pathway.
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Affiliation(s)
- Zi-Wei Chen
- Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, China.,International Joint Laboratory (SYSU-PolyU HK) of Novel Anti-Dementia Drugs of Guangdong, Guangzhou, 510006, China.,National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, 510080, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Zhejiang Pharmaceutical College, Hangzhou, Zhejiang Province, China
| | - Anmin Liu
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
| | - Qingyu Liu
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
| | - Jingkao Chen
- Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, China.,International Joint Laboratory (SYSU-PolyU HK) of Novel Anti-Dementia Drugs of Guangdong, Guangzhou, 510006, China.,National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, 510080, China
| | - Wen-Ming Li
- Department of Pharmacology, School of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Xiao-Juan Chao
- Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, China.,International Joint Laboratory (SYSU-PolyU HK) of Novel Anti-Dementia Drugs of Guangdong, Guangzhou, 510006, China.,National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, 510080, China
| | - Qian Yang
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Pei-Qing Liu
- Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, China.,International Joint Laboratory (SYSU-PolyU HK) of Novel Anti-Dementia Drugs of Guangdong, Guangzhou, 510006, China.,National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, 510080, China
| | - Zi-Xu Mao
- Department of Pharmacology, School of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Rong-Biao Pi
- Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, China. .,International Joint Laboratory (SYSU-PolyU HK) of Novel Anti-Dementia Drugs of Guangdong, Guangzhou, 510006, China. .,National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-sen University, Guangzhou, 510080, China. .,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
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11
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miR-218 suppressed the growth of lung carcinoma by reducing MEF2D expression. Tumour Biol 2015; 37:2891-900. [PMID: 26409449 DOI: 10.1007/s13277-015-4038-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/02/2015] [Indexed: 10/23/2022] Open
Abstract
Lung carcinoma is a deadly malignant disease with poor prognosis and increasing incidence in recent years. However, the molecular mechanism underlying the initiation and progression of lung cancer is still not completely elucidated. Recently, myocyte enhancer factor 2D (MEF2D) has been reported to promote the growth of liver cancer, but its implication in lung cancer is still unknown. This study is aimed to determine the role of MEF2D in lung carcinoma. Quantitative PCR (qPCR) and immunoblot assays showed that MEF2D was overexpressed in lung cancer tissues and cell lines, compared with the matched normal tissues and cell lines. Small interfering RNA (siRNA) suppression of MEF2D was able to reduce the proliferation, survival, and invasion of lung carcinoma cells. The transfection of MEF2D-expressing constructs into normal lung fibroblast cells promoted their proliferation and motility. The role of MEF2D in the growth of lung cancer was also confirmed in mice. Further study revealed that miR-218, which was underexpressed in lung carcinoma, was predicted to bind the 3'-untranslated region (UTR) of MEF2D mRNA. miR-218 was shown to suppress the activity of luciferase with MEF2D 3'-UTR. The changes in miR-218 levels affected the expression of MEF2D in lung cancer cells and normal fibroblast cells. There is also an inverse association between miR-218 abundance and MEF2D levels in the lung carcinoma specimen. Furthermore, the transfection of a plasmid that expressed MEF2D resistance to miR-218 regulation abolished the inhibitory effect of miR-218 on lung cancer cells. Collectively, MEF2D overexpression participated in the growth of lung cancers and its aberrant expression may result from the reduction of tumor suppressor miR-218.
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12
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Indirubin-3-Oxime Effectively Prevents 6OHDA-Induced Neurotoxicity in PC12 Cells via Activating MEF2D Through the Inhibition of GSK3β. J Mol Neurosci 2015; 57:561-70. [PMID: 26346600 DOI: 10.1007/s12031-015-0638-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 08/04/2015] [Indexed: 10/23/2022]
Abstract
Indirubin-3-oxime (I3O), a synthetic derivative of indirubin, was originally designed as potent inhibitors of cyclin-dependent kinases (CDKs) and glycogen synthase kinase 3β (GSK3β) for leukemia therapy. In the current study, we have shown, for the first time, that I3O prevented 6-hydroxydopamine (6OHDA)-induced neuronal apoptosis and intracellular reactive oxygen species accumulation in PC12 cells in a concentration-dependent manner. GSK3β inhibitors but not CDK5 inhibitors reduced the neurotoxicity induced by 6OHDA. Moreover, the activation of GSK3β was observed after 6OHDA treatment. Furthermore, 6OHDA substantially decreased the transcriptional activity of myocyte enhancer factor 2D (MEF2D), a transcription factor that plays an important role in dopaminergic neuron survival, and reduced nuclear localized MEF2D expression. Interestingly, indirubin-3-oxime and GSK3β inhibitors prevented 6OHDA-induced dysregulation of MEF2D. In addition, short hairpin RNA-mediated decrease of MEF2D expression significantly abolished the neuroprotective effects of indirubin-3-oxime. Collectively, our results strongly suggested that indirubin-3-oxime prevented 6OHDA-induced neurotoxicity via activating MEF2D, possibly through the inhibition of GSK3β. In view of the capability of indirubin-3-oxime to cross the blood-brain barrier, our findings further indicated that indirubin-3-oxime might be a novel drug candidate for neurodegenerative disorders, including Parkinson's disease in particular.
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13
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Zhao Y, Li Y, Ma Y, Wang S, Cheng J, Yang T, Sun Z, Kuang Y, Huang H, Fan K, Gu J. Myocyte enhancer factor 2D promotes tumorigenicity in malignant glioma cells. Tumour Biol 2015; 37:601-10. [PMID: 26234765 DOI: 10.1007/s13277-015-3791-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/09/2015] [Indexed: 01/12/2023] Open
Abstract
The prognosis of patients with malignant glioma is always quite poor, and this poor prognosis is probably due to our incomplete understanding of the molecular mechanisms underlying malignant glioma. It is known that myocyte enhancer factor-2D (MEF2D) plays an oncogenic role in hepatocellular carcinoma and promotes the survival of various types of cells. However, little is known about the expression profile and function of MEF2D in malignant glioma. In this study, we investigated the function and expression of MEF2D in malignant glioma. We found that in malignant glioma, there is an aberrantly high expression of MEF2D, which leads to poor prognosis of malignant glioma. The downregulation of MEF2D suppresses the proliferation of malignant glioma cell lines by inducing delay of S and G2/M phases of cell cycle and promoting apoptosis. Furthermore, the overexpression of MEF2D in astrocytes accelerates cell proliferation by regulating cell cycle progression. Furthermore, a mouse malignant glioma model demonstrated that MEF2D deficiency blocks malignant glioma formation in vivo. We conclude that MEF2D may act as a potential oncogene in malignant glioma and thus serve as a candidate target for malignant glioma therapy.
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Affiliation(s)
- Youguang Zhao
- Department of Postgraduate, Third Military Medical University, Chongqing, People's Republic of China.,Department of Urology, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Ying Li
- Department of Cardiology, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Yuan Ma
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Songtao Wang
- Section of Scientific Research and Training, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Jingmin Cheng
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Tao Yang
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Zhiyong Sun
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Yongqin Kuang
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Haidong Huang
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Kexia Fan
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China
| | - Jianwen Gu
- Department of Neurosurgery, Chengdu Military General Hospital, Chengdu, People's Republic of China. .,The 306th Hospital of PLA, Beijing, People's Republic of China.
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14
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Zhao X, Liu M, Li D. Oleanolic acid suppresses the proliferation of lung carcinoma cells by miR-122/Cyclin G1/MEF2D axis. Mol Cell Biochem 2014; 400:1-7. [PMID: 25472877 DOI: 10.1007/s11010-014-2228-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/27/2014] [Indexed: 12/13/2022]
Abstract
Oleanolic acid (OA) is a natural compound from plants with anti-tumor activities. However, the mechanism of the inhibitory effect of OA on cell cycle progression has not been completely explored. We employed several lung carcinoma cell lines to investigate the cell cycle-related molecular pathway affected by OA. The data revealed that OA suppressed the proliferation of lung cancer cells in both dose- and time-dependent manners, along with an increase in miR-122 abundance. The suppression of miR-122 abolished the effect of OA on lung cancer cells. CCNG1 and MEF2D, two putative miR-122 targets, were found to be downregulated by OA treatment. Restoring their expression counteracted the effect of OA on lung carcinoma cells. OA was further shown to induce the expression of miR-122-regulating transcriptional factors in lung cancer cells. Collectively, OA induced cell cycle arrest in lung cancer cells through miR-122/Cyclin G1/MEF2D pathway. This finding may contribute to the understanding of the molecular mechanism of OA's anti-tumor activity.
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Affiliation(s)
- Xiaoming Zhao
- Department of Thoracic Surgery, Shandong Cancer Hospital and Institute, 440 Jiyan Road, Jinan, 250117, Shandong, People's Republic of China
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15
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7,8-dihydroxyflavone protects PC12 cells against 6-hydroxydopamine-induced cell death through modulating PI3K/Akt and JNK pathways. Neurosci Lett 2014; 581:85-8. [PMID: 25139527 DOI: 10.1016/j.neulet.2014.08.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 02/04/2023]
Abstract
We have recently shown that 7,8-dihydroxyflavone (7,8-DHF) protects PC12 cells against 6-OHDA-induced cytotoxicity through its antioxidant activity. In the present study, we investigated the molecular mechanisms underlying the neuronal protective activity of 7,8-DHF. Western blot analysis showed that 6-OHDA (100μM, 24h) enhanced the phosphorylation of JNK and ERK1/2, but it markedly suppressed the expression of p-Akt, implying that 6-OHDA induces PC12 cell death through activating the pro-apoptotic MAPKs pathway but suppressing the survival PI3K/Akt pathway. More importantly, addition of 7,8-DHF fully prevented the activation of JNK and suppression of Akt induced by 6-OHDA. Interestingly, pretreatment with the PI3K-specific inhibitor LY294002 largely blocked 7,8-DHF function in protecting PC12 cells from 6-OHDA-induced cell death. In contrast, the MEK inhibitor PD98059 showed little effect on the protective activity of 7,8-DHF. These results suggest that 7,8-DHF might protect PC12 cells from 6-OHDA-induced cell death through activating PI3K/Akt pathway and inhibiting JNK pathway.
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16
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Shah M, Rajagopalan S, Xu L, Voshavar C, Shurubor Y, Beal F, Andersen JK, Dutta AK. The high-affinity D2/D3 agonist D512 protects PC12 cells from 6-OHDA-induced apoptotic cell death and rescues dopaminergic neurons in the MPTP mouse model of Parkinson's disease. J Neurochem 2014; 131:74-85. [PMID: 24848702 DOI: 10.1111/jnc.12767] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 05/19/2014] [Accepted: 05/20/2014] [Indexed: 02/06/2023]
Abstract
In this study, in vitro and in vivo experiments were carried out with the high-affinity multifunctional D2/D3 agonist D-512 to explore its potential neuroprotective effects in models of Parkinson's disease and the potential mechanism(s) underlying such properties. Pre-treatment with D-512 in vitro was found to rescue rat adrenal Pheochromocytoma PC12 cells from toxicity induced by 6-hydroxydopamine administration in a dose-dependent manner. Neuroprotection was found to coincide with reductions in intracellular reactive oxygen species, lipid peroxidation, and DNA damage. In vivo, pre-treatment with 0.5 mg/kg D-512 was protective against neurodegenerative phenotypes associated with systemic administration of MPTP, including losses in striatal dopamine, reductions in numbers of DAergic neurons in the substantia nigra (SN), and locomotor dysfunction. These observations strongly suggest that the multifunctional drug D-512 may constitute a novel viable therapy for Parkinson's disease.
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Affiliation(s)
- Mrudang Shah
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA
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17
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Rotenone upregulates alpha-synuclein and myocyte enhancer factor 2D independently from lysosomal degradation inhibition. BIOMED RESEARCH INTERNATIONAL 2013; 2013:846725. [PMID: 23984410 PMCID: PMC3745903 DOI: 10.1155/2013/846725] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/18/2013] [Accepted: 07/02/2013] [Indexed: 12/21/2022]
Abstract
Dysfunctions of chaperone-mediated autophagy (CMA), the main catabolic pathway for alpha-synuclein, have been linked to the pathogenesis of Parkinson's disease (PD). Since till now there is limited information on how PD-related toxins may affect CMA, in this study we explored the effect of mitochondrial complex I inhibitor rotenone on CMA substrates, alpha-synuclein and MEF2D, and effectors, lamp2A and hsc70, in a human dopaminergic neuroblastoma SH-SY5Y cell line. Rotenone induced an upregulation of alpha-synuclein and MEF2D protein levels through the stimulation of their de novo synthesis rather than through a reduction of their CMA-mediated degradation. Moreover, increased MEF2D transcription resulted in higher nuclear protein levels that exert a protective role against mitochondrial dysfunction and oxidative stress. These results were compared with those obtained after lysosome inhibition with ammonium chloride. As expected, this toxin induced the cytosolic accumulation of both alpha-synuclein and MEF2D proteins, as the result of the inhibition of their lysosome-mediated degradation, while, differently from rotenone, ammonium chloride decreased MEF2D nuclear levels through the downregulation of its transcription, thus reducing its protective function. These results highlight that rotenone affects alpha-synuclein and MEF2D protein levels through a mechanism independent from lysosomal degradation inhibition.
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18
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Mount MP, Zhang Y, Amini M, Callaghan S, Kulczycki J, Mao Z, Slack RS, Anisman H, Park DS. Perturbation of transcription factor Nur77 expression mediated by myocyte enhancer factor 2D (MEF2D) regulates dopaminergic neuron loss in response to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). J Biol Chem 2013; 288:14362-14371. [PMID: 23536182 DOI: 10.1074/jbc.m112.439216] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We have earlier reported the critical nature of calpain-CDK5-MEF2 signaling in governing dopaminergic neuronal loss in vivo. CDK5 mediates phosphorylation of the neuronal survival factor myocyte enhancer factor 2 (MEF2) leading to its inactivation and loss. However, the downstream factors that mediate MEF2-regulated survival are unknown. Presently, we define Nur77 as one such critical downstream survival effector. Following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment in vivo, Nur77 expression in the nigrostriatal region is dramatically reduced. This loss is attenuated by expression of MEF2. Importantly, MEF2 constitutively binds to the Nur77 promoter in neurons under basal conditions. This binding is lost following 1-methyl-4-phenylpyridinium treatment. Nur77 deficiency results in significant sensitization to dopaminergic loss following 1-methyl-4-phenylpyridinium/MPTP treatment, in vitro and in vivo. Furthermore, Nur77-deficient MPTP-treated mice displayed significantly reduced levels of dopamine and 3,4-Dihydroxyphenylacetic acid in the striatum as well as elevated post synaptic FosB activity, indicative of increased nigrostriatal damage when compared with WT MPTP-treated controls. Importantly, this sensitization in Nur77-deficient mice was rescued with ectopic Nur77 expression in the nigrostriatal system. These results indicate that the inactivation of Nur77, induced by loss of MEF2 activity, plays a critical role in nigrostriatal degeneration in vivo.
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Affiliation(s)
- Matthew P Mount
- Department of Neuroscience and Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Yi Zhang
- Department of Neuroscience and Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Mandana Amini
- Department of Neuroscience and Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Steve Callaghan
- Department of Neuroscience and Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Jerzy Kulczycki
- Institute of Neuroscience, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Zixu Mao
- Departments of Pharmacology and Neurology, Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Ruth S Slack
- Department of Neuroscience and Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Hymie Anisman
- Institute of Neuroscience, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - David S Park
- Department of Neuroscience and Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada; Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang 627-706, South Korea.
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19
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Dietrich JB. The MEF2 family and the brain: from molecules to memory. Cell Tissue Res 2013; 352:179-90. [DOI: 10.1007/s00441-013-1565-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/10/2013] [Indexed: 12/31/2022]
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20
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Chen JH, Ou HP, Lin CY, Lin FJ, Wu CR, Chang SW, Tsai CW. Carnosic Acid Prevents 6-Hydroxydopamine-Induced Cell Death in SH-SY5Y Cells via Mediation of Glutathione Synthesis. Chem Res Toxicol 2012; 25:1893-901. [DOI: 10.1021/tx300171u] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Jing-Hsien Chen
- Department of Nutrition, Chung Shan Medical University, Taichung, Taiwan
| | - Hsin-Ping Ou
- Department of Health Food, Chung Chou University of Science and Technology, Changua,
Taiwan
| | - Chia-Yuan Lin
- Department of Nutrition, China Medical University, Taichung, Taiwan
| | - Fung-Ju Lin
- Department of Nutrition, China Medical University, Taichung, Taiwan
| | - Chi-Rei Wu
- The School of Chinese Pharmaceutical
Sciences and Chinese Medicine Resources, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Shu-Wei Chang
- Department of Medicinal Botanicals
and Health Care, Dayeh University, Changhua,
Taiwan
| | - Chia-Wen Tsai
- Department of Nutrition, China Medical University, Taichung, Taiwan
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21
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Speksnijder N, Christensen KV, Didriksen M, De Kloet ER, Datson NA. Glucocorticoid receptor and myocyte enhancer factor 2 cooperate to regulate the expression of c-JUN in a neuronal context. J Mol Neurosci 2012; 48:209-18. [PMID: 22622902 PMCID: PMC3413818 DOI: 10.1007/s12031-012-9809-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 05/07/2012] [Indexed: 12/31/2022]
Abstract
The glucocorticoid receptor (GR) and myocyte enhancer factor 2 (MEF2) are transcription factors involved in neuronal plasticity. c-JUN, a target gene of GR and MEF2, plays a role in regulating both synaptic strength and synapse number. The aim of this study was to investigate the nature of this dual regulation of c-JUN by GR and MEF2 in a neuronal context. First, we showed that GR mediates the dexamethasone-induced suppression of c-JUN mRNA expression. Next, we observed that GR activation resulted in an increase in phosphorylation of MEF2, a post-translational modification known to change MEF2 from a transcriptional enhancer to a repressor. In addition, we observed an enhanced binding of MEF2 to genomic sites directly upstream of the c-JUN gene upon GR activation. Finally, in primary hippocampal neuronal cultures, knockdown of MEF2 not only reduced c-JUN expression levels but abolished GR regulation of c-JUN expression. This suggests that MEF2 is necessary for GR regulation of c-JUN. In conclusion, for the first time, we show that activated GR requires MEF2 to regulate c-JUN. At the same time, GR influences MEF2 activity and DNA binding. These results give novel insight into the molecular interplay of GR and MEF2 in the control of genes important for neuronal plasticity.
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Affiliation(s)
- Niels Speksnijder
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research (LACDR), Leiden University Medical Center, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
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22
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Zhao F, Zhang JB, Cai TJ, Liu XQ, Liu MC, Ke T, Chen JY, Luo WJ. Manganese induces p21 expression in PC12 cells at the transcriptional level. Neuroscience 2012; 215:184-95. [PMID: 22542671 DOI: 10.1016/j.neuroscience.2012.04.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 04/01/2012] [Accepted: 04/13/2012] [Indexed: 01/28/2023]
Abstract
Manganese is a common environmental and occupational pollutant. Excessive intake of manganese can cause toxicity known as manganism. Recently it has been demonstrated that unusual expression of cell cycle proteins and aberrant cell cycle progression in the central nervous system are involved in the pathogenesis of neurodegenerative diseases. The present studies were initiated to investigate whether p21 are induced after manganese exposure and its potential effects in vitro, with particular attention being given to understand the underlying regulatory mechanism of p21 induction by manganese in this process. We found that manganese induced DAergic cells injury and upregulation of p21 levels in nigrostriatal regions. Treatment of the PC12 cells with manganese resulted in a time- and concentration-dependent loss of cell viability. Analysis of cell cycle profile indicated that manganese blocked cell cycle progression by arresting the cell cycle at G2/M phase. Moreover, manganese treatment resulted in an increase in the mRNA and protein levels of p21, but did not have the same effect on other related factors. Silencing p21 by RNA interference showed a marked reversal of both G2/M arrest and the decrease in cell viability induced by manganese. Manganese did not stabilize the p21 protein and mRNA, and caused a marked increase in p21 mRNA levels together with an increase in its promoter activity, indicating a transcriptional mechanism. Overall, the in vivo and in vitro data suggest that exposure to manganese can increase p21 levels. An altered cell cycle status of PC12 cells can be induced by manganese through p21 up-regulation, and the induction of p21 occurs at the transcriptional level via promoter activation and mRNA induction.
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Affiliation(s)
- F Zhao
- Department of Occupational and Environmental Health and The Ministry of Education Key Laboratory of Hazard Assessment and Control in Special Operational Environment, Fourth Military Medical University, Xi'an 710032, China
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23
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Suppression of a MEF2-KLF6 survival pathway by PKA signaling promotes apoptosis in embryonic hippocampal neurons. J Neurosci 2012; 32:2790-803. [PMID: 22357862 DOI: 10.1523/jneurosci.3609-11.2012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In the mammalian nervous system, regulation of transcription factor activity is a crucial determinant of neuronal cell survival, differentiation, and death. The myocyte enhancer factor 2 (MEF2) transcription factors have been implicated in cellular processes underlying neuronal survival and differentiation. A core component of the MEF2 complex is the MEF2D subunit. Recently, we reported that cAMP-dependent protein kinase (cAMP/PKA) signaling negatively regulates MEF2D function in myogenic cells. Here, we assessed whether cAMP signaling converges on the prosurvival role of MEF2D in Sprague Dawley rat embryonic (E18) hippocampal neurons. Initially, we observed that experimental induction of cAMP/PKA signaling promotes apoptosis in primary hippocampal neurons as indicated by TUNEL and FACS analysis. Luciferase reporter gene assays revealed that PKA potently represses MEF2D trans-activation properties in neurons. This effect was largely reversed by engineered neutralizing mutations of PKA phospho-acceptor sites on MEF2D (S121/190A). Krüppel-like factor 6 (KLF6) was identified as a key transcriptional target of MEF2 in hippocampal neurons, and siRNA-mediated knockdown of KLF6 expression promotes neuronal cell death and also antagonizes the prosurvival role of MEF2D. These observations have important implications for understanding the pathways controlling cell survival and death in the mammalian nervous system.
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Folch J, Junyent F, Verdaguer E, Auladell C, Pizarro JG, Beas-Zarate C, Pallàs M, Camins A. Role of Cell Cycle Re-Entry in Neurons: A Common Apoptotic Mechanism of Neuronal Cell Death. Neurotox Res 2011; 22:195-207. [DOI: 10.1007/s12640-011-9277-4] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 09/02/2011] [Accepted: 09/13/2011] [Indexed: 01/24/2023]
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