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Jia XT, Ye-Tian, Yuan-Li, Zhang GJ, Liu ZQ, Di ZL, Ying XP, Fang Y, Song EF, Qi JS, Pan YF. Exendin-4, a glucagon-like peptide 1 receptor agonist, protects against amyloid-β peptide-induced impairment of spatial learning and memory in rats. Physiol Behav 2016; 159:72-9. [PMID: 26992957 DOI: 10.1016/j.physbeh.2016.03.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 03/10/2016] [Accepted: 03/14/2016] [Indexed: 02/08/2023]
Abstract
Type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) share specific molecular mechanisms, and agents with proven efficacy in one may be useful against the other. The glucagon-like peptide-1 (GLP-1) receptor agonist exendin-4 has similar properties to GLP-1 and is currently in clinical use for T2DM treatment. Thus, this study was designed to characterize the effects of exendin-4 on the impairment of learning and memory induced by amyloid protein (Aβ) and its probable molecular underlying mechanisms. The results showed that (1) intracerebroventricular (i.c.v.) injection of Aβ1-42 resulted in a significant decline of spatial learning and memory of rats in water maze tests; (2) pretreatment with exendin-4 effectively and dose-dependently protected against the Aβ1-42-induced impairment of spatial learning and memory; (3) exendin-4 treatment significantly decreased the expression of Bax and cleaved caspase-3 and increased the expression of Bcl2 in Aβ1-42-induced Alzheimer's rats. The vision and swimming speed of the rats among all groups in the visible platform tests did not show any difference. These findings indicate that systemic pretreatment with exendin-4 can effectively prevent the behavioral impairment induced by neurotoxic Aβ1-42, and the underlying protective mechanism of exendin-4 may be involved in the Bcl2, Bax and caspase-3 pathways. Thus, the application of exendin-4 or the activation of its signaling pathways may be a promising strategy to ameliorate the degenerative processes observed in AD.
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Affiliation(s)
- Xiao-Tao Jia
- Department of Neurology, The Affiliated Xi'an Central Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710003, PR China
| | - Ye-Tian
- Department of Neurology, The Affiliated Xi'an Central Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710003, PR China
| | - Yuan-Li
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan 030001, PR China
| | - Ge-Juan Zhang
- Department of Neurology, The Affiliated Xi'an Central Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710003, PR China
| | - Zhi-Qin Liu
- Department of Neurology, The Affiliated Xi'an Central Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710003, PR China
| | - Zheng-Li Di
- Department of Neurology, The Affiliated Xi'an Central Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710003, PR China
| | - Xiao-Ping Ying
- Department of Pathology, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 712046, PR China
| | - Yan Fang
- Department of Pathology, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 712046, PR China
| | - Er-Fei Song
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada
| | - Jin-Shun Qi
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan 030001, PR China.
| | - Yan-Fang Pan
- Department of Pathology, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 712046, PR China.
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Naert G, Ferré V, Meunier J, Keller E, Malmström S, Givalois L, Carreaux F, Bazureau JP, Maurice T. Leucettine L41, a DYRK1A-preferential DYRKs/CLKs inhibitor, prevents memory impairments and neurotoxicity induced by oligomeric Aβ25-35 peptide administration in mice. Eur Neuropsychopharmacol 2015; 25:2170-82. [PMID: 26381812 DOI: 10.1016/j.euroneuro.2015.03.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 03/10/2015] [Accepted: 03/22/2015] [Indexed: 01/07/2023]
Abstract
Dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs) and cdc2-like kinases (CLKs) are implicated in the onset and progression of Down syndrome (DS) and Alzheimer's disease (AD). DYRK1A has emerged as a possible link between amyloid-β (Aβ) and Tau, the major pathological proteins in AD. We here assessed the neuroprotective potential of a novel inhibitor of DYRKs/CLKs. The Leucettine L41, acting preferentially on DYRK1A, was tested in Aβ25-35-treated mice, a nontransgenic model of AD-like toxicity. We co-injected intracerebroventricularly oligomeric Aβ25-35 peptide and L41 in Swiss male mice. After 7 days, they were submitted to behavioral tests addressing spatial and non-spatial, short- and long-term memories. The oxidative stress, apoptotic markers, kinases involved in Tau phosphorylation, and synaptic integrity were analyzed by Western blot and ELISA in the hippocampus. L41, tested at 0.4, 1.2, 4 µg, prevented the Aβ25-35-induced memory deficits in the Y-maze, passive avoidance and water-maze tests, with the most active dose being 4 µg. The inhibitor prevented the Aβ25-35-induced oxidative stress, as revealed by measures of lipid peroxidation levels and reactive oxygen species accumulation, and abolished Aβ25-35-induced expression of pro-apoptotic markers. L41 prevented the Aβ25-35-induced decrease of AKT activation and increase of glycogen synthase kinase-3β (GSK-3β) activation, resulting in a decrease of Tau phosphorylation. Finally, L41 restored Aβ25-35-reduced levels of synaptic markers. The novel DYRK1A-preferential inhibitor L41 therefore prevented Aβ25-35-induced memory impairments and neurotoxicity in the mouse hippocampus. These in vivo data highlighted particularly DYRK1A as a major kinase involved in Aβ pathology and suggested therapeutic developments for DYRK1A inhibitors in AD.
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Affiliation(s)
- Gaëlle Naert
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France; Amylgen, 2196, boulevard de la Lironde, Montferrier-sur-Lez 34980, France
| | - Valentine Ferré
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France
| | - Johann Meunier
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France; Amylgen, 2196, boulevard de la Lironde, Montferrier-sur-Lez 34980, France
| | - Emeline Keller
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France; Amylgen, 2196, boulevard de la Lironde, Montferrier-sur-Lez 34980, France
| | - Susanna Malmström
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France; Amylgen, 2196, boulevard de la Lironde, Montferrier-sur-Lez 34980, France
| | - Laurent Givalois
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France
| | - François Carreaux
- Université Rennes, CNRS UMR 6226, Campus de Beaulieu, Bat. 10A, 10C, Avenue du Général Leclerc, Rennes Cedex 35042, France
| | - Jean-Pierre Bazureau
- Université Rennes, CNRS UMR 6226, Campus de Beaulieu, Bat. 10A, 10C, Avenue du Général Leclerc, Rennes Cedex 35042, France
| | - Tangui Maurice
- Université Montpellier, INSERM U. 1198, place Eugène Bataillon, Montpellier Cedex 5 34095, France; Amylgen, 2196, boulevard de la Lironde, Montferrier-sur-Lez 34980, France.
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Puangmalai N, Somani A, Thangnipon W, Ballard C, Broadstock M. A genetically immortalized human stem cell line: a promising new tool for Alzheimer's disease therapy. EXCLI JOURNAL 2015; 14:1135-14. [PMID: 27152108 PMCID: PMC4849102 DOI: 10.17179/excli2015-560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/08/2015] [Indexed: 01/05/2023]
Abstract
Amyloid-β peptides and hyper-phosphorylated tau are the main pathological hallmarks of Alzheimer's disease (AD). Given the recent failure of several large-scale clinical trials and the lack of disease-modifying pharmacological treatments, there is an urgent need to develop alternative therapies. A clinical grade human CTX0E03 neural stem cell line has recently passed phase I trials in people with stroke. However, this cell line has not been investigated in other neurodegenerative disorders. This study investigates the survival of CTX0E03 cells under conditions based on the underlying AD pathology. Cell viability assays showed a concentration dependence of this cell line to the toxic effects of Aβ1-42, but not Aβ1-40, and okadaic acid, a phosphatase 2A inhibitor. Notably, CTX0E03 cell line displayed toxicity at concentrations significantly higher than both rat neural stem cells and those previously reported for primary cultures. These results suggest CTX0E03 cells could be developed for clinical trials in AD patients.
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Affiliation(s)
- Nicha Puangmalai
- King’s College London, Wolfson Centre for Age-Related Diseases, London, SE1 1UL, UK
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhonpathom 73170, Thailand
| | - Alyma Somani
- King’s College London, Wolfson Centre for Age-Related Diseases, London, SE1 1UL, UK
| | - Wipawan Thangnipon
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhonpathom 73170, Thailand
| | - Clive Ballard
- King’s College London, Wolfson Centre for Age-Related Diseases, London, SE1 1UL, UK
| | - Martin Broadstock
- King’s College London, Wolfson Centre for Age-Related Diseases, London, SE1 1UL, UK
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Yao K, Wu J, Zhang J, Bo J, Hong Z, Zu H. Protective Effect of DHT on Apoptosis Induced by U18666A via PI3K/Akt Signaling Pathway in C6 Glial Cell Lines. Cell Mol Neurobiol 2015; 36:801-9. [PMID: 26340949 DOI: 10.1007/s10571-015-0263-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 08/27/2015] [Indexed: 11/27/2022]
Abstract
Various useful animal models, such as Alzheimer's disease and Niemann-Pick disease, were provided by U18666A. However, the pathogenesis of U18666A-induced diseases, including U18666A-mediated apoptosis, remains incompletely elucidated, and therapeutic strategies are still limited. Dihydrotestosterone (DHT) has been reported to contribute to the prevention and treatment of neurodegenerative disorders. Our study investigated the neuroprotective activity of DHT in U18666A-related diseases. Apoptosis of C6 cells was detected by Hoechst 33258 fluorescent staining and flow cytometry with annexin V-FITC/PI dual staining. Cell viability was assessed using Cell Counting Kit-8. Expression of apoptosis-related proteins, such as Akt, seladin-1, Bcl-2 family proteins, and caspase-3, was determined using Western blot. Our results demonstrated that the apoptotic rate of C6 cells significantly increased after U18666A addition, but was remarkably reduced after DHT treatment. Pretreatment with DHT attenuated U18666A-induced cell viability loss. PI3K inhibitor LY294002 could suppress DHT anti-apoptotic effect. Furthermore, we discovered that U18666A could significantly downregulate seladin-1 expression in a dose-dependent manner, but no significant change was observed in Bcl-xL, Bax, and P-Akt protein expressions. Compared with U18666A-treated group, the expression of P-Akt, seladin-1, and Bcl-xL significantly increased, and the expression of Bax and caspase-3 remarkably reduced after DHT treatment. However, in the presence of LY294002, the effect of DHT was reversed. In conclusion, we found that seladin-1 may take part in U18666A-induced apoptosis. DHT may inhibit U18666A-induced apoptosis by regulating downstream apoptosis-related proteins including seladin-1, caspase-3, Bcl-xL, and Bax through activation of the PI3K/Akt signal pathway.
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Affiliation(s)
- Kai Yao
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Junfeng Wu
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Jianfeng Zhang
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Jimei Bo
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Zhen Hong
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Hengbing Zu
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China.
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Wang W, Zhang G, Gu H, Liu Y, Lao J, Li K, Guan H. Role of CtBP2 in the Apoptosis of Retinal Ganglion Cells. Cell Mol Neurobiol 2015; 35:633-40. [PMID: 25627828 DOI: 10.1007/s10571-015-0158-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/13/2015] [Indexed: 10/24/2022]
Abstract
Glaucoma damages the optic nerve and is a leading cause of irreversible blindness, and its pathogenesis remains unclear. C-terminal-binding protein 2 (CtBP2) is a transcriptional repressor which plays an important role in central nervous system injury and repair. Using the glaucoma model of DBA/2J mouse whose retina ganglion cells (RGCs) were degenerating with the process of glaucoma, we demonstrated for the first time the special relationship between CtBP2 protein and RGCs. Our research indicated that the expression of CtBP2 was gradually decreased with aging by the means of Western blotting. The CtBP2 immunoreactivity-positive cells were present in the various retinal layers, and CtBP2-positive cells were dramatically decreased in ganglion cell layer. Our research also found ectopic expression of CtBP2 can protect the apoptosis of primary mouse RGC cells induced by L-glutamate. These results suggest that CtBP2 may have a potential therapeutic effect in protecting RGC.
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Affiliation(s)
- Wenwen Wang
- Department of Pathology of Traditional Chinese Medicine Hospital, Jiangyin, Jiangsu, China
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Akhter R, Sanphui P, Das H, Saha P, Biswas SC. The regulation of p53 up-regulated modulator of apoptosis by JNK/c-Jun pathway in β-amyloid-induced neuron death. J Neurochem 2015; 134:1091-103. [PMID: 25891762 DOI: 10.1111/jnc.13128] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/10/2015] [Accepted: 03/31/2015] [Indexed: 12/29/2022]
Abstract
Neuronal loss in selective areas of brain underlies the pathology of Alzheimer's disease (AD). Recent evidences place oligomeric β-amyloid (Aβ) central to the disease. However, mechanism of neuron death in response to Aβ remains elusive. Activation of the c-Jun N-terminal kinase (JNK) pathway and induction of the AP-1 transcription factor c-Jun are reported in AD. However, targets of JNK/c-Jun in Aβ-induced neuron death are mostly unknown. Our study shows that pro-apoptotic proteins, Bim (Bcl-2 interacting mediator of cell death) and Puma (p53 up-regulated modulator of apoptosis) are targets of c-Jun in Aβ-treated neurons. We demonstrate that the JNK/c-Jun pathway is activated, in cultures of cortical neurons following treatment with oligomeric Aβ and in AD transgenic mice, and that inhibition of this pathway by selective inhibitor blocks induction of Puma by Aβ. We also find that both JNK and p53 pathways co-operatively regulate Puma expression in Aβ-treated neurons. Moreover, we identified a novel AP1-binding site on rat puma gene which is necessary for direct binding of c-Jun with Puma promoter. Finally, we find that knocking down of c-Jun by siRNA provides significant protection from Aβ toxicity and that induction of Bim and Puma by Aβ in neurons requires c-Jun. Taken together, our results suggest that both Bim and Puma are target of c-Jun and elucidate the intricate regulation of Puma expression by JNK/c-Jun and p53 pathways in neurons upon Aβ toxicity. JNK/c-Jun pathway is shown to be activated in neurons of the Alzheimer's disease (AD) brain and plays a vital role in neuron death in AD models. However, downstream targets of c-Jun in this disease have not been thoroughly elucidated. Our study shows that two important pro-apoptotic proteins, Bim (Bcl-2 interacting mediator of cell death) and Puma (p53 up-regulated modulator of apoptosis) are targets of c-Jun in Aβ-treated neurons. We demonstrate that the JNK/c-jun pathway is activated, in cultures of cortical neurons following treatment with oligomeric Aβ and in AD transgenic mice, and that inhibition of this pathway by selective inhibitor blocks induction of Puma by Aβ. We have also observed functional co-operation of both JNK and p53 pathway in regulation of Puma under Aβ toxicity. Most importantly, we identified a novel AP1-binding site on rat puma gene which is necessary for direct binding of c-Jun with Puma promoter. Thus, our results suggest that both Bim and Puma are target of c-Jun and elucidate the intricate regulation of Puma expression by JNK/c-Jun and p53 pathways in neurons upon Aβ toxicity.
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Affiliation(s)
- Rumana Akhter
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Priyankar Sanphui
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Hrishita Das
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Pampa Saha
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Subhas Chandra Biswas
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
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Sendrowski K, Sobaniec W, Stasiak-Barmuta A, Sobaniec P, Popko J. Study of the protective effects of nootropic agents against neuronal damage induced by amyloid-beta (fragment 25–35) in cultured hippocampal neurons. Pharmacol Rep 2015; 67:326-31. [DOI: 10.1016/j.pharep.2014.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/21/2014] [Accepted: 09/30/2014] [Indexed: 12/16/2022]
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Hu WY, He ZY, Yang LJ, Zhang M, Xing D, Xiao ZC. The Ca(2+) channel inhibitor 2-APB reverses β-amyloid-induced LTP deficit in hippocampus by blocking BAX and caspase-3 hyperactivation. Br J Pharmacol 2015; 172:2273-85. [PMID: 25521332 DOI: 10.1111/bph.13048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/30/2014] [Accepted: 12/04/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE At the early stage of Alzheimer's disease (AD), the accumulation of β-amyloid (Aβ) oligomers disturbs intracellular Ca(2+) homeostasis and disrupts synaptic plasticity of brain neurons. Prevention of Aβ-induced synaptic failure remains an unsolved problem for the treatment of AD. Here, the effects of 2-aminoethoxydiphenyl borate (2-APB), a non-specific, but moderately potent Ca(2+) channel inhibitor, on Aβ-induced deficit of synaptic long-term potentiation (LTP) and the underlying molecular mechanisms were explored. EXPERIMENTAL APPROACH We used hippocampal slices and primary cultures of hippocampal neurons from C57BL/6 mice. Methods applied in our study included electrophysiological recording, membrane protein extraction, Western blot assay and Ca(2+) imaging. KEY RESULTS 2-APB at 10 μM effectively reversed suppression by oligomeric Aβ1-42 (500 nM) of LTP in hippocampal slices. 2-APB also restored phosphorylation and trafficking of the glutamate receptor subunit GluA1 in Aβ-treated hippocampal slices, supporting its protective action on synaptic function. Aβ-mediated abnormal neuronal [Ca(2+) ]i elevation and hyperactivation of the mitochondrial apoptotic proteins BAX, caspase-3, and glycogen synthase kinase-3β, were blocked by 2-APB pretreatment. Moreover, the defict in long term potentiation deficit in hippocampal slices from APPswe /PS1ΔE 9 gene mutant mice was rescued by 2-APB at 10 μM. CONCLUSIONS AND IMPLICATION These data demonstrate that 2-APB is a potentially useful chemical to protect synaptic plasticity against neurotoxic effects of Aβ in AD.
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Affiliation(s)
- Wei-Yan Hu
- The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, China; Shunxi-Monash Immune Regeneration and Neuroscience Laboratories, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia; School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming, China
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Bing L, Wu J, Zhang J, Chen Y, Hong Z, Zu H. DHT inhibits the Aβ25-35-induced apoptosis by regulation of seladin-1, survivin, XIAP, bax, and bcl-xl expression through a rapid PI3-K/Akt signaling in C6 glial cell lines. Neurochem Res 2014; 40:41-8. [PMID: 25347962 DOI: 10.1007/s11064-014-1463-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 10/15/2014] [Accepted: 10/23/2014] [Indexed: 11/28/2022]
Abstract
Previous evidences indicate that androgen is neuroprotective in the brain. However, the underling mechanisms remain to be fully elucidated. Moreover, it is controversial whether dihydrotestosterone (DHT) modulates the expression of apoptosis-related effectors, such as survivin, XIAP, bax, and bcl-xl proteins mediated by the PI3-K/Akt pathway, which contributes to androgen neuroprotection. In this study using a C6 glial cell model, apoptotic cells were detected by flow cytometry. Akt, seladin-1, survivin, XIAP, bcl-xl, and bax protein expression is investigated by Western blot. After amyloid β-protein fragment (Aβ25-35) treatment, apoptotic cells at early (annexin V+, PI-) and late (annexin V+, PI+) stages were significantly increased. Apoptosis at early and late was obviously inhibited in the presence of DHT. The effect of DHT was markedly blocked by PI3-K inhibitor LY294002.To elicit the mechanism of DHT protection, the expression of seladin-1, survivin, XIAP, bax, and bcl-xl protein was determined in C6 cells treated with Aβ25-35, DHT, or LY294002. Aβ25-35 significantly downregulated the expression of seladin-1, survivin, XIAP, bcl-xl protein and upregulated the expression of bax protein. DHT significantly inhibited the expression of bax, seladin-1, survivin, XIAP, and bcl-xl protein induced by Aβ25-35. Further, we found the effect of DHT was significantly inhibited by LY294002. Collectively, in a C6 glial cell model, we firstly found that DHT inhibits Aβ25-35-induced apoptosis by a rapid nongenic PI-3K/Akt activation as well as regulation of seladin-1, survivin, XIAP, bcl-xl, and bax proteins.
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Affiliation(s)
- Lelin Bing
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
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Dong YL, Wang YM, Yang HJ, Yang XZ, Yu HJ. Phytoestrogen α-zearalanol exerts antiapoptotic effects in differentiated pc12 cells via oestrogen receptor α. Basic Clin Pharmacol Toxicol 2014; 116:110-4. [PMID: 25052567 DOI: 10.1111/bcpt.12296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 07/10/2014] [Indexed: 10/25/2022]
Abstract
Our previous studies have demonstrated that phytoestrogen α-zearalanol (α-ZAL) possesses potential benefits in alleviating cell apoptotic death just like oestrogen. However, the underlying mechanism is not fully understood. This study was designed to test the hypothesis that the neuroprotective effect of α-ZAL is mediated by oestrogen receptor (ER) as α-ZAL owns the benzene ring structure may interact with ER. The present results showed a significant increase in apoptosis in differentiated PC12 cells after a 24-hr exposure to amyloid β-peptide fragment 25-35 (Aβ25-35 ), accompanied by decreasing of bcl-2 expression and increasing bax expression, whereas a pre-treatment with α-ZAL ameliorated these changes induced by Aβ25-35 . In addition, the α-ZAL-mediated cytoprotection was abrogated by ERα antagonist but not by ERβ antagonist. In summary, these data suggest that α-ZAL intervenes against Aβ-induced apoptosis via intersecting bcl-2-bax apoptotic pathway in an ERα-sensitive manner.
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Affiliation(s)
- Yi Long Dong
- The School of Medicine, Yunnan University, Kunming, Yunnan, China
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Protective effect of a sesamin derivative, 3-bis (3-methoxybenzyl) butane-1, 4-diol on Aβ-stressed PC12 cells. Arch Pharm Res 2014; 38:543-8. [PMID: 25074037 DOI: 10.1007/s12272-014-0426-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 06/12/2014] [Indexed: 10/25/2022]
Abstract
Amyloid beta-protein (Aβ) is involved in the pathogenesis of Alzheimer's disease (AD). Aβ induces free radical production in neuronal cells, leading to oxidative stress and up-regulation of c-Jun N-terminal kinases (JNK), extracellular-signal-regulated kinases (ERK), p38 mitogen-activated protein kinase (MAPK) pathways and pro-apoptotic Bax expression. Sesamin has been shown to have protection to several models of neurodegenerative diseases by its antioxidant and anti-inflammatory properties. In the present study, we examined the neuroprotective effect of a sesamin derivative, 3-bis (3-methoxybenzyl) butane-1,4-diol (BBD) on Aβ1-42 induced cytotoxicity of PC12 cells. Aβ1-42 induced lipid peroxidation, calcium, reactive oxygen species from the PC12 cells. The effect of BBD on these harmful factors and the related signaling pathways were examined by biochemical and western blot assays. The result showed that BBD protected PC12 cells from Aβ1-42 induced cytotoxicity with the increased cell viability and acetylcholine release, and the decreased lactate dehydrogenase, malondialdehyde and calcium release. BBD significantly reduced Aβ-induced JNK, ERK, p38 MAPK pathways and Bax expression in PC12 cells. Therefore the neuroprotective effect of BBD on Aβ-induced cytotoxicity was involved with antioxidant and anti-inflammatory effects. The result would help the development of new CNS drug for protection of AD.
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Zeldich E, Chen CD, Colvin TA, Bove-Fenderson EA, Liang J, Tucker Zhou TB, Harris DA, Abraham CR. The neuroprotective effect of Klotho is mediated via regulation of members of the redox system. J Biol Chem 2014; 289:24700-15. [PMID: 25037225 DOI: 10.1074/jbc.m114.567321] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Generation of reactive oxygen species (ROS), leading to oxidative damage and neuronal cell death, plays an important role in the pathogenesis of neurodegenerative disorders, including Alzheimer disease. The present study aimed to examine the mechanism by which the anti-aging protein Klotho exerts neuroprotective effects against neuronal damage associated with neurodegeneration and oxidative stress. Pretreatment of rat primary hippocampal neurons and mouse hippocampal neuronal cell line HT22 with recombinant Klotho protected these cells from glutamate and oligomeric amyloid β (oAβ)-induced cytotoxicity. In addition, primary hippocampal neurons obtained from Klotho-overexpressing mouse embryos were more resistant to both cytotoxic insults, glutamate and oAβ, compared with neurons from wild-type littermates. An antioxidative stress array analysis of neurons treated with Klotho revealed that Klotho significantly enhances the expression of the thioredoxin/peroxiredoxin (Trx/Prx) system with the greatest effect on the induction of Prx-2, an antioxidant enzyme, whose increase was confirmed at the mRNA and protein levels. Klotho-induced phosphorylation of the PI3K/Akt pathway, a pathway important in apoptosis and longevity, was associated with sustained inhibitory phosphorylation of the transcription factor forkhead box O3a (FoxO3a) and was essential for the induction of Prx-2. Down-regulation of Prx-2 expression using a lentivirus harboring shRNA almost completely abolished the ability of Klotho to rescue neurons from glutamate-induced death and significantly, but not completely, inhibited cell death mediated by oAβ, suggesting that Prx-2 is a key modulator of neuroprotection. Thus, our results demonstrate, for the first time, the neuroprotective role of Klotho and reveal a novel mechanism underlying this effect.
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Affiliation(s)
| | | | | | | | | | - Tracey B Tucker Zhou
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
| | | | - Carmela R Abraham
- From the Department of Biochemistry, Program in Molecular Medicine, and Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
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Yu W, Bonnet M, Farso M, Ma K, Chabot JG, Martin E, Torriglia A, Guan Z, McLaurin J, Quirion R, Krantic S. The expression of apoptosis inducing factor (AIF) is associated with aging-related cell death in the cortex but not in the hippocampus in the TgCRND8 mouse model of Alzheimer's disease. BMC Neurosci 2014; 15:73. [PMID: 24915960 PMCID: PMC4070095 DOI: 10.1186/1471-2202-15-73] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/30/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent evidence has suggested that Alzheimer's disease (AD)-associated neuronal loss may occur via the caspase-independent route of programmed cell death (PCD) in addition to caspase-dependent mechanisms. However, the brain region specificity of caspase-independent PCD in AD-associated neurodegeneration is unknown. We therefore used the transgenic CRND8 (TgCRND8) AD mouse model to explore whether the apoptosis inducing factor (AIF), a key mediator of caspase-independent PCD, contributes to cell loss in selected brain regions in the course of aging. RESULTS Increased expression of truncated AIF (tAIF), which is directly responsible for cell death induction, was observed at both 4- and 6-months of age in the cortex. Concomitant with the up-regulation of tAIF was an increase in the nuclear translocation of this protein. Heightened tAIF expression or translocation was not observed in the hippocampus or cerebellum, which were used as AD-vulnerable and relatively AD-spared regions, respectively. The cortical alterations in tAIF levels were accompanied by increased Bax expression and mitochondrial translocation. This effect was preceded by a significant reduction in ATP content and an increase in reactive oxygen species (ROS) production, detectable at 2 months of age despite negligible amounts of amyloid-beta peptides (Aβ). CONCLUSIONS Taken together, these data suggest that AIF is likely to play a region-specific role in AD-related caspase-independent PCD, which is consistent with aging-associated mitochondrial impairment and oxidative stress.
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Affiliation(s)
- Wenfeng Yu
- Key laboratory of Molecular Biology, Guiyang Medical University, Guiyang 550004, China
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Mathilde Bonnet
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Mark Farso
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Keran Ma
- Department Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jean-Guy Chabot
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | | | | | - Zhizhong Guan
- Key laboratory of Molecular Biology, Guiyang Medical University, Guiyang 550004, China
- Department of Pathology in the Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China
| | - JoAnne McLaurin
- Department Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Rémi Quirion
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Slavica Krantic
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
- Centre de Recherche des Cordeliers, UMRS872, Paris, France
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Ono T, Kuhara S. A novel method for gathering and prioritizing disease candidate genes based on construction of a set of disease-related MeSH® terms. BMC Bioinformatics 2014; 15:179. [PMID: 24917541 PMCID: PMC4068192 DOI: 10.1186/1471-2105-15-179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 06/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding the molecular mechanisms involved in disease is critical for the development of more effective and individualized strategies for prevention and treatment. The amount of disease-related literature, including new genetic information on the molecular mechanisms of disease, is rapidly increasing. Extracting beneficial information from literature can be facilitated by computational methods such as the knowledge-discovery approach. Several methods for mining gene-disease relationships using computational methods have been developed, however, there has been a lack of research evaluating specific disease candidate genes. RESULTS We present a novel method for gathering and prioritizing specific disease candidate genes. Our approach involved the construction of a set of Medical Subject Headings (MeSH) terms for the effective retrieval of publications related to a disease candidate gene. Information regarding the relationships between genes and publications was obtained from the gene2pubmed database. The set of genes was prioritized using a "weighted literature score" based on the number of publications and weighted by the number of genes occurring in a publication. Using our method for the disease states of pain and Alzheimer's disease, a total of 1101 pain candidate genes and 2810 Alzheimer's disease candidate genes were gathered and prioritized. The precision was 0.30 and the recall was 0.89 in the case study of pain. The precision was 0.04 and the recall was 0.6 in the case study of Alzheimer's disease. The precision-recall curve indicated that the performance of our method was superior to that of other publicly available tools. CONCLUSIONS Our method, which involved the use of a set of MeSH terms related to disease candidate genes and a novel weighted literature score, improved the accuracy of gathering and prioritizing candidate genes by focusing on a specific disease.
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Affiliation(s)
| | - Satoru Kuhara
- Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki Higashi-ku, Fukuoka 812-8581, Japan.
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Song J, Hur BE, Bokara KK, Yang W, Cho HJ, Park KA, Lee WT, Lee KM, Lee JE. Agmatine improves cognitive dysfunction and prevents cell death in a streptozotocin-induced Alzheimer rat model. Yonsei Med J 2014; 55:689-99. [PMID: 24719136 PMCID: PMC3990080 DOI: 10.3349/ymj.2014.55.3.689] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/18/2014] [Accepted: 02/18/2014] [Indexed: 12/03/2022] Open
Abstract
PURPOSE Alzheimer's disease (AD) results in memory impairment and neuronal cell death in the brain. Previous studies demonstrated that intracerebroventricular administration of streptozotocin (STZ) induces pathological and behavioral alterations similar to those observed in AD. Agmatine (Agm) has been shown to exert neuroprotective effects in central nervous system disorders. In this study, we investigated whether Agm treatment could attenuate apoptosis and improve cognitive decline in a STZ-induced Alzheimer rat model. MATERIALS AND METHODS We studied the effect of Agm on AD pathology using a STZ-induced Alzheimer rat model. For each experiment, rats were given anesthesia (chloral hydrate 300 mg/kg, ip), followed by a single injection of STZ (1.5 mg/kg) bilaterally into each lateral ventricle (5 μL/ventricle). Rats were injected with Agm (100 mg/kg) daily up to two weeks from the surgery day. RESULTS Agm suppressed the accumulation of amyloid beta and enhanced insulin signal transduction in STZ-induced Alzheimer rats [experimetal control (EC) group]. Upon evaluation of cognitive function by Morris water maze testing, significant improvement of learning and memory dysfunction in the STZ-Agm group was observed compared with the EC group. Western blot results revealed significant attenuation of the protein expressions of cleaved caspase-3 and Bax, as well as increases in the protein expressions of Bcl2, PI3K, Nrf2, and γ-glutamyl cysteine synthetase, in the STZ-Agm group. CONCLUSION Our results showed that Agm is involved in the activation of antioxidant signaling pathways and activation of insulin signal transduction. Accordingly, Agm may be a promising therapeutic agent for improving cognitive decline and attenuating apoptosis in AD.
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Affiliation(s)
- Juhyun Song
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
| | - Bo Eun Hur
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
- Brain Korea 21 Plus Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Kiran Kumar Bokara
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
| | - Wonsuk Yang
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
| | - Hyun Jin Cho
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
| | - Kyung Ah Park
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
| | - Won Taek Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
| | - Kyoung Min Lee
- Department of Neurology, Seoul National University College of Medicine, Seoul, Korea
| | - Jong Eun Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
- Brain Korea 21 Plus Project for Medical Science, Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
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Akhter R, Sanphui P, Biswas SC. The essential role of p53-up-regulated modulator of apoptosis (Puma) and its regulation by FoxO3a transcription factor in β-amyloid-induced neuron death. J Biol Chem 2014; 289:10812-10822. [PMID: 24567336 DOI: 10.1074/jbc.m113.519355] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Neurodegeneration underlies the pathology of Alzheimer disease (AD). The molecules responsible for such neurodegeneration in AD brain are mostly unknown. Recent findings indicate that the BH3-only proteins of the Bcl-2 family play an essential role in various cell death paradigms, including neurodegeneration. Here we report that Puma (p53-up-regulated modulator of apoptosis), an important member of the BH3-only protein family, is up-regulated in neurons upon toxic β-amyloid 1-42 (Aβ(1-42)) exposure both in vitro and in vivo. Down-regulation of Puma by specific siRNA provides significant protection against neuron death induced by Aβ(1-42). We further demonstrate that the activation of p53 and inhibition of PI3K/Akt pathways induce Puma. The transcription factor FoxO3a, which is activated when PI3K/Akt signaling is inhibited, directly binds with the Puma gene and induces its expression upon exposure of neurons to oligomeric Aβ(1-42). Moreover, Puma cooperates with another BH3-only protein, Bim, which is already implicated in AD. Our results thus suggest that Puma is activated by both p53 and PI3K/Akt/FoxO3a pathways and cooperates with Bim to induce neuron death in response to Aβ(1-42).
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Affiliation(s)
- Rumana Akhter
- Cell Biology and Physiology Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Priyankar Sanphui
- Cell Biology and Physiology Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Subhas Chandra Biswas
- Cell Biology and Physiology Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India.
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67
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Sanphui P, Pramanik SK, Chatterjee N, Moorthi P, Banerji B, Biswas SC. Efficacy of cyclin dependent kinase 4 inhibitors as potent neuroprotective agents against insults relevant to Alzheimer's disease. PLoS One 2013; 8:e78842. [PMID: 24244372 PMCID: PMC3823981 DOI: 10.1371/journal.pone.0078842] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 09/16/2013] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease with no cure till today. Aberrant activation of cell cycle regulatory proteins is implicated in neurodegenerative diseases including AD. We and others have shown that Cyclin dependent kinase 4 (Cdk4) is activated in AD brain and is required for neuron death. In this study, we tested the efficiency of commercially available Cdk4 specific inhibitors as well as a small library of synthetic molecule inhibitors targeting Cdk4 as neuroprotective agents in cellular models of neuron death. We found that several of these inhibitors significantly protected neuronal cells against death induced by nerve growth factor (NGF) deprivation and oligomeric beta amyloid (Aβ) that are implicated in AD. These neuroprotective agents inhibit specifically Cdk4 kinase activity, loss of mitochondrial integrity, induction of pro-apoptotic protein Bim and caspase3 activation in response to NGF deprivation. The efficacies of commercial and synthesized inhibitors are comparable. The synthesized molecules are either phenanthrene based or naphthalene based and they are synthesized by using Pschorr reaction and Buchwald coupling respectively as one of the key steps. A number of molecules of both kinds block neurodegeneration effectively. Therefore, we propose that Cdk4 inhibition would be a therapeutic choice for ameliorating neurodegeneration in AD and these synthetic Cdk4 inhibitors could lead to development of effective drugs for AD.
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Affiliation(s)
- Priyankar Sanphui
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | | | - Nandini Chatterjee
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Ponnusamy Moorthi
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Biswadip Banerji
- Chemistry Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
- * E-mail: (SCB); (BB)
| | - Subhas Chandra Biswas
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
- * E-mail: (SCB); (BB)
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Sindi IA, Tannenberg RK, Dodd PR. Role for the neurexin-neuroligin complex in Alzheimer's disease. Neurobiol Aging 2013; 35:746-56. [PMID: 24211009 DOI: 10.1016/j.neurobiolaging.2013.09.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/20/2013] [Accepted: 09/22/2013] [Indexed: 11/29/2022]
Abstract
Synaptic damage is a critical hallmark of Alzheimer's disease, and the best correlate with cognitive impairment ante mortem. Synapses, the loci of communication between neurons, are characterized by signature protein combinations arrayed at tightly apposed pre- and post-synaptic sites. The most widely studied trans-synaptic junctional complexes, which direct synaptogenesis and foster the maintenance and stability of the mature terminal, are conjunctions of presynaptic neurexins and postsynaptic neuroligins. Fluctuations in the levels of neuroligins and neurexins can sway the balance between excitatory and inhibitory neurotransmission in the brain, and could lead to damage of synapses and dendrites. This review summarizes current understanding of the roles of neurexins and neuroligins proteolytic processing in synaptic plasticity in the human brain, and outlines their possible roles in β-amyloid metabolism and function, which are central pathogenic events in Alzheimer's disease progression.
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Affiliation(s)
- Ikhlas A Sindi
- Centre for Psychiatry and Clinical Neuroscience, School of Medicine, The University of Queensland, Brisbane, Australia
| | - Rudolph K Tannenberg
- Centre for Psychiatry and Clinical Neuroscience, School of Medicine, The University of Queensland, Brisbane, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Peter R Dodd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.
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Building blocks of the apoptotic pore: how Bax and Bak are activated and oligomerize during apoptosis. Cell Death Differ 2013; 21:196-205. [PMID: 24162660 DOI: 10.1038/cdd.2013.139] [Citation(s) in RCA: 292] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 09/03/2013] [Accepted: 09/03/2013] [Indexed: 12/18/2022] Open
Abstract
The central role of the Bcl-2 family in regulating apoptotic cell death was first identified in the 1980s. Since then, significant in-roads have been made in identifying the multiple members of this family, characterizing their form and function and understanding how their interactions determine whether a cell lives or dies. In this review we focus on the recent progress made in characterizing the proapoptotic Bcl-2 family members, Bax and Bak. This progress has resolved longstanding controversies, but has also challenged established theories in the apoptosis field. We will discuss different models of how these two proteins become activated and different 'modes' by which they are inhibited by other Bcl-2 family members. We will also discuss novel conformation changes leading to Bak and Bax oligomerization and speculate how these oligomers might permeabilize the mitochondrial outer membrane.
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70
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Suh EC, Jung YJ, Kim YA, Park EM, Lee SJ, Lee KE. Knockout of Toll-like receptor 2 attenuates Aβ25-35-induced neurotoxicity in organotypic hippocampal slice cultures. Neurochem Int 2013; 63:818-25. [PMID: 24161618 DOI: 10.1016/j.neuint.2013.10.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 09/13/2013] [Accepted: 10/15/2013] [Indexed: 12/21/2022]
Abstract
Toll-like receptors (TLRs), which have been implicated in various neuroinflammatory responses, are thought to act in defense mechanisms by inhibiting neuronal cell death in Alzheimer's disease. In this study, we evaluated the effects of TLR2 on amyloid beta peptide 25-35 (Aβ25-35)-induced neuronal cell death, synaptic dysfunction, and microglial activation in organotypic hippocampal slice cultures (OHSCs) from wild-type (WT) C57BL/6 mice and TLR2-knockout (KO) mice. In WT mice, Aβ25-35 induced β-amyloid aggregation and surrounding TLR2 expression. And, propidium iodide (PI) uptake, which is a measure of cell death, increased in a dose-dependent manner in slices with Aβ25-35 treatment. In the Aβ25-35-treated TLR2-KO OHSCs, the PI uptake was significantly attenuated to the control level, indicating that the cells were less susceptible to Aβ25-35-induced neuronal toxicity. In the ultrastructural analysis, nuclear shrinkage, slightly swollen mitochondria, and degraded organelles were detected in the Aβ25-35-treated slices from WT mice but not in the Aβ25-35-treated slices from TLR2-KO, suggesting the resistance of TLR2-KO to Aβ25-35-induced neurotoxicity. In Aβ25-35-treated OHSCs of WT mice, the levels of phosphorylated tau were increased and the levels of synaptophysin were decreased in a dose-dependent manner, but they were not changed in OHSCs of TLR2-KO mice. In WT mice, Aβ25-35 increased total protein level and immunoreactivity of Iba-1, which was colocalized with TLR2. However, there were no significant changes in the slices of Aβ25-35-treated TLR2-KO mice. These results suggested that TLR2 may play a role in Aβ25-35-induced neuronal cell loss and synaptic dysfunction through the activation of microglia in OHSCs.
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Affiliation(s)
- Eun Cheng Suh
- Department of Pharmacology and Ewha Medical Research Institute, School of Medicine, Ewha Womans University, Seoul, South Korea
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Li X, Li Z, Zhou W, Xing X, Huang L, Tian L, Chen J, Chen C, Ma X, Yang Z. Overexpression of 4EBP1, p70S6K, Akt1 or Akt2 differentially promotes Coxsackievirus B3-induced apoptosis in HeLa cells. Cell Death Dis 2013; 4:e803-9. [PMID: 24030155 PMCID: PMC3789189 DOI: 10.1038/cddis.2013.331] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/04/2013] [Accepted: 08/06/2013] [Indexed: 12/17/2022]
Abstract
Our previous studies have shown that the inhibition of phosphatidylinositol 3-kinase (PI3K) or mTOR complex 1 can obviously promote the Coxsackievirus B3 (CVB3)-induced apoptosis of HeLa cells by regulating the expression of proapoptotic factors. To further illustrate it, Homo sapiens eIF4E-binding protein 1 (4EBP1), p70S6 kinase (p70S6K), Akt1 and Akt2 were transfected to HeLa cells, respectively. And then, we established the stable transfected cell lines. Next, after CVB3 infection, apoptosis in different groups was determined by flow cytometry; the expressions of Bim, Bax, caspase-9 and caspase-3 were examined by real-time fluorescence quantitative PCR and western blot analysis; the expression of CVB3 mRNA and viral capsid protein VP1 were also analyzed by real-time fluorescence quantitative PCR, western blot analysis and immunofluorescence, respectively. At the meantime, CVB3 replication was observed by transmission electron microscope. We found that CVB3-induced cytopathic effect and apoptosis in transfected groups were more obvious than that in controls. Unexpectedly, apoptosis rate in Akt1 group was higher than others at the early stage after viral infection and decreased with the viral-infected time increasing, which was opposite to other groups. Compared with controls, the expression of CVB3 mRNA was increased at 3, 6, 12 and 24 h postinfection (p. i.) in all groups. At the meantime, VP1 expression in 4EBP1 group was higher than control during the process of infection, while the expressions in the other groups were change dynamically. Moreover, overexpression of 4EBP1 did not affect the mRNA expressions of Bim, Bax, caspase-9 and caspase-3; while protein expressions of Bim and Bax were decreased, the self-cleavages of caspase-9 and caspase-3 were stimulated. Meanwhile, overexpression of p70S6K blocked the CVB3-induced Bim, Bax and caspase-9 expressions but promoted the self-cleavage of caspase-9. In the Akt1 group, it is noteworthy that the expressions of Bim protein were higher than controls at 3 and 6 h p. i. but lower at 24 h p. i., and the expression of Bax protein were higher at 6 and 24 h p. i., while their mRNA expressions were all decreased. Furthermore, overexpression of Akt1 stimulated the procaspase-9 and procaspase-3 expression but blocked their self-cleavages. Overexpression of Akt2, however, had little effect on Bim, Bax and caspase-3, while prevented caspase-9 from self-cleavage at the late stage of CVB3 infection. As stated above, our results demonstrated that overexpression of 4EBP1, p70S6K, Akt1 or Akt2 could promote the CVB3-induced apoptosis in diverse degree via different mediating ways in viral replication and proapoptotic factors in BcL-2 and caspase families. As 4EBP1, p70S6K and Akt are the important substrates of PI3K and mammalian target of rapamycin (mTOR), we further illustrated the role of PI3K/Akt/mTOR signaling pathway in the process of CVB3-induced apoptosis.
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Affiliation(s)
- X Li
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, China
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72
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Dai X, Chang P, Zhu Q, Liu W, Sun Y, Zhu S, Jiang Z. Chitosan oligosaccharides protect rat primary hippocampal neurons from oligomeric β-amyloid 1-42-induced neurotoxicity. Neurosci Lett 2013; 554:64-9. [PMID: 23999027 DOI: 10.1016/j.neulet.2013.08.046] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/20/2013] [Accepted: 08/22/2013] [Indexed: 10/26/2022]
Abstract
β-Amyloid peptide (Aβ), the major component of senile plaques in patients with Alzheimer's disease (AD), is believed to facilitate the progressive neurodegeneration that occurs in this disease. Mounting natural compounds are proved to be potential candidates for the prevention and treatment of AD. Chitosan oligosaccharides (COSs), the enzymatic hydrolysates of chitosan, have been reported to possess diverse biological activities. Here we investigated the effect of COSs on oligomeric Aβ-mediated toxicity in rat primary hippocampal neurons. Pretreatment with COSs markedly inhibited cell death induced by Aβ exposure as determined by cell viability assay and lactate dehydrogenase release assay. In parallel, the generation of reactive oxygen species and lipid peroxidation were attenuated by COSs. Furthermore, our results indicated that COSs remarkably prevented Aβ-induced cell apoptosis as manifested by depressing the elevation of Bax/Bcl-2 ratio and caspase-3 activation, suggesting that the neuroprotective effect of COSs could be partially due to apoptosis regulation. In addition, pretreatment with COSs significantly blocked Aβ-induced phosphorylation of c-Jun N-terminal kinase. Taken together, these findings may shed light on the role of COSs as a potential therapeutic agent for AD.
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Affiliation(s)
- Xueling Dai
- Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing 100191, China; Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing 100191, China; Research Institute for Science and Technology of Functional Food, Beijing Union University, Beijing 100191, China
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Li X, Zhang J, Chen Z, Yang L, Xing X, Ma X, Yang Z. Both PI3K- and mTOR-signaling pathways take part in CVB3-induced apoptosis of Hela cells. DNA Cell Biol 2013; 32:359-70. [PMID: 23705975 DOI: 10.1089/dna.2013.2003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This work illustrated the mechanism contributing to the process of Phosphatidylinostiol 3-kinase (PI3K)/protein kinase B (PKB)/mammalian target of rapamycin (mTOR) signaling pathway, which has been demonstrated to play an important role in virus-induced apoptosis, which contributes to the Viral Myocarditis (VMC) pathogeneses. We examined the expression of Bax, Bim, caspase-3, caspase-9, and viral replication after Coxsackievirus B3 (CVB3) infection using the mTOR inhibitor and PI3K inhibitor pretreated HeLa cells, respectively. Apoptosis in different groups was determined by flow cytometry. Bax, Bim, caspase-9, and caspase-3 were examined by semiquantitative polymerase chain reaction (PCR) and Western blot analysis. The expression of CVB3 mRNA and viral capsid protein VP1 were analyzed by semiquantitative PCR and Western blot analysis distinctively. We found that rapamycin and LY294002 promote CVB3-induced cytopathic effect (CPE) and apoptosis. CVB3 replication in host cells is mediated in mRNA and protein expression by rapamycin and LY294002. Moreover, comparing with controls, at 12 and 24 h of postinfection (p.i.), Bim and Bax expression increased in cells after treated with rapamycin or LY294002, which also stimulates the activation of procaspase-9, and the CVB3-induced caspase-3 self-cleavage. However, in the meantime, the mRNA expression of caspase-9 and caspase-3 did not have an obvious change. In summary, our results demonstrated that the mTOR-signaling pathway plays an important role in CVB3-induced CPE and apoptosis, which is indispensable in VMC, via regulating Bim, Bax, caspase-9, caspase-3, and viral replication. Our findings may provide a new perspective and a deeper understanding of the mechanism of CVB3-induced apoptosis which, in turn, may help with the development of new therapy for the CVB3 infection.
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Affiliation(s)
- Xin Li
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, China
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Abstract
The molecules that mediate death of selective neurons in Alzheimer's disease (AD) are mostly unknown. The Forkhead transcription factor FoxO3a has emerged as an important mediator of cell fate including apoptosis. When phosphorylated by Akt, it is localized in the cytosol as an inactive complex bound with 14-3-3 protein. For activation and localization of FoxO3a in the nucleus, further modifications are required, such as phosphorylation by mammalian sterile 20-like kinase 1 (MST1) and arginine methylation by protein arginine methyltransferase1. We report here that Akt-mediated phosphorylation of FoxO3a is diminished in neurons exposed to oligomeric β-amyloid (Aβ), in vitro and in vivo. We also find that oligomeric Aβ activates FoxO3a by MST1 phosphorylation and arginine methylation in primary cultures of hippocampal and cortical neurons. Moreover, FoxO3a translocates from the cytosol to nucleus in cultured neurons in response to Aβ. Most importantly, the nuclear redistribution of FoxO3a is significantly increased in Aβ-overexpressing AβPPswe-PS1dE9 mice and Aβ-infused rat brains. We further find that FoxO3a is essential for loss of neurons and neural networks in response to Aβ. Recent reports implicate Bim, a pro-apoptotic member of Bcl-2 family, in neuron death in AD, as a key target of this transcription factor. We show that Bim is a direct target of FoxO3a in Aβ-treated neurons. Our findings thus indicate that FoxO3a is activated, translocated to the nucleus and mediates neuron death via Bim in response to Aβ toxicity.
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Affiliation(s)
- P Sanphui
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
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Kong J, Ren G, Jia N, Wang Y, Zhang H, Zhang W, Chen B, Cao Y. Effects of Nicorandil in Neuroprotective Activation of PI3K/AKT Pathways in a Cellular Model of Alzheimer's Disease. Eur Neurol 2013; 70:233-41. [DOI: 10.1159/000351247] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 04/08/2013] [Indexed: 11/19/2022]
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Diet and aging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:741468. [PMID: 22928085 PMCID: PMC3425961 DOI: 10.1155/2012/741468] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 07/12/2012] [Accepted: 07/16/2012] [Indexed: 11/17/2022]
Abstract
Nutrition has important long-term consequences for health that are not only limited to the individual but can be passed on to the next generation. It can contribute to the development and progression of chronic diseases thus effecting life span. Caloric restriction (CR) can extend the average and maximum life span and delay the onset of age-associated changes in many organisms. CR elicits coordinated and adaptive stress responses at the cellular and whole-organism level by modulating epigenetic mechanisms (e.g., DNA methylation, posttranslational histone modifications), signaling pathways that regulate cell growth and aging (e.g., TOR, AMPK, p53, and FOXO), and cell-to-cell signaling molecules (e.g., adiponectin). The overall effect of these adaptive stress responses is an increased resistance to subsequent stress, thus delaying age-related changes and promoting longevity. In human, CR could delay many diseases associated with aging including cancer, diabetes, atherosclerosis, cardiovascular disease, and neurodegenerative diseases. As an alternative to CR, several CR mimetics have been tested on animals and humans. At present, the most promising alternatives to the use of CR in humans seem to be exercise, alone or in combination with reduced calorie intake, and the use of plant-derived polyphenol resveratrol as a food supplement.
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