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Neuroprotective effects of donepezil against Aβ25-35-induced neurotoxicity. Eur J Med Res 2022; 27:219. [PMID: 36307893 PMCID: PMC9617393 DOI: 10.1186/s40001-022-00862-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 10/20/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to investigate the neuroprotective effect of donepezil against β-amyloid25-35 (Aβ25-35)-induced neurotoxicity and the possible mechanism. Methods PC12 cells were conventionally cultured. Serial concentrations of Aβ25-35 and donepezil (0, 0.5, 1, 5, 10, 20 and 50 μmol/L) were added to the PC12 cells, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) staining was performed to detect the effects of these treatments on PC 12 viability. The PC 12 cells were pretreated with 1, 5, 10, 20 or 50 μmol/L donepezil two hours before 20 μmol/L Aβ25-35 was added to pretreatment groups A, B, C, D and E. Normal control group I and the 20 μmol/L Aβ25-35-treated group were selected. An MTT assay was used to detect PC12 cell viability, and the level of lactate dehydrogenase (LDH) was determined. PC12 cells were pretreated with 10 μmol/L GF109203X (a protein kinase C [PKC] antagonist) 30 min before 10 μmol/L donepezil was added to pretreatment group F, and normal control group II, the 10 μmol/L GF109203X-treated group and the 10 μmol/L donepezil-treated group were chosen. The expression of phosphorylation-PKC (P-PKC) and its major substrate phosphorylated myristoylated alanine-rich protein C kinase substrate (P-MARCKS) was measured by Western blotting. The effects of donepezil on the subcellular distribution of the PKCα and PKCε isoforms were detected by immunofluorescence staining. Results Treatment with Aβ25-35 (5, 10, 20 or 50 μmol/L) for 24 h significantly (P < 0.05) decreased PC 12 cell viability in a dose-dependent manner. Compared with the PC12 cells in the control group, those in the 20 μmol/L Aβ25-35-treated group exhibited lower viability but higher LDH release. Compared with the 20 μmol/L Aβ25–35-treated group, pretreatment groups B, C, D and E exhibited significantly (P < 0.05) increased cell viability but significantly (P < 0.05) decreased LDH release. Western blotting demonstrated that compared with control, 10 μmol/L donepezil promoted PKC and MARCKS phosphorylation and that the expression of P-PKC and P-MARCKS in pretreatment group F was significantly (P < 0.05) lower than that in the donepezil-treated group. Immunofluorescence staining revealed that the PKCα and PKCε isoforms were located mainly in the cytoplasm of PC12 control cells, whereas donepezil increased the expression of the PKCα and PKCε isoforms in the membrane fraction. The Western blot results showed that donepezil altered the subcellular distribution of the PKCα and PKCε isoforms by decreasing their expression in the cytosolic fraction but increasing their expression in the membrane fraction. Conclusion Donepezil can antagonize Aβ25–350-induced neurotoxicity in PC 12 cells, and PKC activation may account for the neuroprotective effect of donepezil.
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Vitória JJM, Trigo D, da Cruz E Silva OAB. Revisiting APP secretases: an overview on the holistic effects of retinoic acid receptor stimulation in APP processing. Cell Mol Life Sci 2022; 79:101. [PMID: 35089425 PMCID: PMC11073327 DOI: 10.1007/s00018-021-04090-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 11/18/2021] [Accepted: 12/01/2021] [Indexed: 01/03/2023]
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide and is characterized by the accumulation of the β-amyloid peptide (Aβ) in the brain, along with profound alterations in phosphorylation-related events and regulatory pathways. The production of the neurotoxic Aβ peptide via amyloid precursor protein (APP) proteolysis is a crucial step in AD development. APP is highly expressed in the brain and is complexly metabolized by a series of sequential secretases, commonly denoted the α-, β-, and γ-cleavages. The toxicity of resulting fragments is a direct consequence of the first cleaving event. β-secretase (BACE1) induces amyloidogenic cleavages, while α-secretases (ADAM10 and ADAM17) result in less pathological peptides. Hence this first cleavage event is a prime therapeutic target for preventing or reverting initial biochemical events involved in AD. The subsequent cleavage by γ-secretase has a reduced impact on Aβ formation but affects the peptides' aggregating capacity. An array of therapeutic strategies are being explored, among them targeting Retinoic Acid (RA) signalling, which has long been associated with neuronal health. Additionally, several studies have described altered RA levels in AD patients, reinforcing RA Receptor (RAR) signalling as a promising therapeutic strategy. In this review we provide a holistic approach focussing on the effects of isoform-specific RAR modulation with respect to APP secretases and discuss its advantages and drawbacks in subcellular AD related events.
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Affiliation(s)
- José J M Vitória
- Department of Medical Sciences, Neurosciences and Signalling Group, Institute of Biomedicine, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Diogo Trigo
- Department of Medical Sciences, Neurosciences and Signalling Group, Institute of Biomedicine, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Odete A B da Cruz E Silva
- Department of Medical Sciences, Neurosciences and Signalling Group, Institute of Biomedicine, University of Aveiro, 3810-193, Aveiro, Portugal.
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Mardani M, Tiraihi T, Bathaie SZ, Mirnajafi-Zadeh J. Comparison of the proteome patterns of adipose-derived stem cells with those treated with selegiline using a two dimensional gel electrophoresis analysis. Biotech Histochem 2019; 95:176-185. [PMID: 31589072 DOI: 10.1080/10520295.2019.1656345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Adipose derived stem cells (ADSCs) are multipotent and can transdifferentiate into neural stem cells. We investigated the transdifferentiation of ADSCs to neural phenotype (NP) cells using selegiline and two-dimensional electrophoresis (2-DE). The perinephric and inguinal fat of rats was collected and used to isolate ADSCs that were characterized by immunophenotyping using flow cytometry. The ADSCs were differentiated into osteogenic and lipogenic cells. The NP cells were generated using 10-9 mM selegiline and characterized by immunocytochemical staining of nestin and neurofilament 68 (NF-68), and by qRT-PCR of nestin, neurod1 and NF68. Total protein of ADSCs and NP cells was extracted and their proteome patterns were examined using 2-DE. ADSCs carried CD73, CD44 and CD90 cell markers, but not CD34. ADSCs were differentiated into osteocyte and adipocyte lineages. The differentiated NP cells expressed nestin, neuro d1 and NF-68. The proteome pattern of ADSCs was compared with that of NP cells and eight spots showed more than a two fold increase in protein expression. The molecular weights and isoelectric points of these highly expressed proteins were estimated using Melanie software. We compared these results with those of the mouse proteomic database using the protein isoelectric point database, and the functions of the eight proteins in differentiation of NP cells were predicted using the UniProt database. The probable identities of the proteins that showed higher expression in NP cells included cholinesterase, GFRa2, protein kinase C (PKC-eta) and RING finger protein 121. The sequences of the proteins identified from mouse database were aligned by comparing them with similar proteins in rat database using the Basic Local Alignment Search Tool (BLAST). The E values of all aligned proteins were zero, which indicates consistency of the matched protein. These proteins participate in differentiation of the neuron and their overexpression causes ADSCs transdifferentiation into NP cells.
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Affiliation(s)
- M Mardani
- Department of Anatomical Sciences, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - T Tiraihi
- Department of Anatomical Sciences, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - S Z Bathaie
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - J Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Fries JWU. MicroRNAs as markers to monitor endothelin-1 signalling and potential treatment in renal disease: Carcinoma - proteinuric damage - toxicity. Biol Cell 2019; 111:169-186. [PMID: 30866090 DOI: 10.1111/boc.201800059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/01/2019] [Accepted: 02/25/2019] [Indexed: 12/11/2022]
Abstract
This review highlights new developments in miRNA as diagnostic and surveillance tools in diseases damaging the renal proximal tubule mediated by endothelin in the field of renal carcinoma, proteinuric kidney disease and tubulotoxicity. A new mechanism in the miRNA regulation of proteins leads to the binding of the miRNA directly to the DNA with premature transcriptional termination and hence the formation of truncated protein isoforms (Mxi2, Vim3). These isoforms are mediated through miRNA15a or miRNA 498, respectively. ET-1 can activate a cytoplasmic complex consisting of NF-κB p65, MAPK p38α, and PKCα. Consequently, PKCα does not transmigrate into the nucleus, which leads to the loss of suppression of a primiRNA15a, maturation of this miRNA in the cytoplasm, tubular secretion and detectability in the urine. This mechanism has been shown in renal cell carcinoma and in proteinuric disease as a biomarker for the activation of the signalling pathway. Similarly, ET-1 induced miRNA 498 transmigrates into the nucleus to form the truncated protein Vim3, which is a biomarker for the benign renal cell tumour, oncocytoma. In tubulotoxicity, ET-1 induced miRNa133a down-regulating multiple-drug-resistant related protein-2, relevant for proteinuric and cisplatin/cyclosporine A toxicity. Current advantages and limitations of miRNAs as urinary biomarkers are discussed.
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Affiliation(s)
- Jochen W U Fries
- Department of Pathology, University Hospital of Koeln, 50931, Koeln, Germany
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Kiyota T, Machhi J, Lu Y, Dyavarshetty B, Nemati M, Zhang G, Mosley RL, Gelbard HA, Gendelman HE. URMC-099 facilitates amyloid-β clearance in a murine model of Alzheimer's disease. J Neuroinflammation 2018; 15:137. [PMID: 29729668 PMCID: PMC5935963 DOI: 10.1186/s12974-018-1172-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 04/23/2018] [Indexed: 01/19/2023] Open
Abstract
Background The mixed lineage kinase type 3 inhibitor URMC-099 facilitates amyloid-beta (Aβ) clearance and degradation in cultured murine microglia. One putative mechanism is an effect of URMC-099 on Aβ uptake and degradation. As URMC-099 promotes endolysosomal protein trafficking and reduces Aβ microglial pro-inflammatory activities, we assessed whether these responses affect Aβ pathobiogenesis. To this end, URMC-099’s therapeutic potential, in Aβ precursor protein/presenilin-1 (APP/PS1) double-transgenic mice, was investigated in this model of Alzheimer’s disease (AD). Methods Four-month-old APP/PS1 mice were administered intraperitoneal URMC-099 injections at 10 mg/kg daily for 3 weeks. Brain tissues were examined by biochemical, molecular and immunohistochemical tests. Results URMC-099 inhibited mitogen-activated protein kinase 3/4-mediated activation and attenuated β-amyloidosis. Microglial nitric oxide synthase-2 and arginase-1 were co-localized with lysosomal-associated membrane protein 1 (Lamp1) and Aβ. Importatly, URMC-099 restored synaptic integrity and hippocampal neurogenesis in APP/PS1 mice. Conclusions URMC-099 facilitates Aβ clearance in the brain of APP/PS1 mice. The multifaceted immune modulatory and neuroprotective roles of URMC-099 make it an attractive candidate for ameliorating the course of AD. This is buttressed by removal of pathologic Aβ species and restoration of the brain’s microenvironment during disease.
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Affiliation(s)
- Tomomi Kiyota
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Safety Assessment, Genentech Inc., South San Francisco, CA, USA
| | - Jatin Machhi
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Yaman Lu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Bhagyalaxmi Dyavarshetty
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Maryam Nemati
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Gang Zhang
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - R Lee Mosley
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Harris A Gelbard
- Center for Neurotherapeutics Discovery, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA
| | - Howard E Gendelman
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA. .,Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA. .,Department of Pharmacology and Experimental Neuroscience, 985880 Nebraska Medical Center, Omaha, NE, 68198-5880, USA.
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Xu YQ, Sun ZQ, Wang YT, Xiao F, Chen MW. Function of Nogo-A/Nogo-A receptor in Alzheimer's disease. CNS Neurosci Ther 2015; 21:479-85. [PMID: 25732725 DOI: 10.1111/cns.12387] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/01/2015] [Accepted: 01/02/2015] [Indexed: 12/11/2022] Open
Abstract
Nogo-A is a protein inhibiting axonal regeneration, which is considered a major obstacle to nerve regeneration after injury in mammals. Rapid progress has been achieved in new physiopathological function of Nogo-A in Alzheimer's disease in the past decade. Recent research shows that through binding to Nogo-A receptor, Nogo-A plays an important role in Alzheimer's disease (AD) pathogenesis. Particularly, Nogo-A/Nogo-A receptors modulate the generation of amyloid β-protein (Aβ), which is thought to be a major cause of AD. This review describes the recent development of Nogo-A, Nogo-A receptor, and downstream signaling involved in AD and pharmacological basis of therapeutic drugs. We concluded the Nogo-A/Nogo-A receptor provide new insight into potential mechanisms and promising therapy strategies in AD.
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Affiliation(s)
- Ying-Qi Xu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Zhong-Qing Sun
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, China
| | - Yi-Tao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Fei Xiao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.,Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, China
| | - Mei-Wan Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
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Yang HQ, Sun ZK, Yang WM, Han HM, Ma JJ, Li W. Effects of rivastigmine on secreted amyloid precursor protein and beta-amyloid secretion in neuroblastoma SK-N-SH cells. NEUROCHEM J+ 2013. [DOI: 10.1134/s181971241303015x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Hong-Qi Y, Zhi-Kun S, Sheng-Di C. Current advances in the treatment of Alzheimer's disease: focused on considerations targeting Aβ and tau. Transl Neurodegener 2012; 1:21. [PMID: 23210837 PMCID: PMC3514124 DOI: 10.1186/2047-9158-1-21] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 10/23/2012] [Indexed: 12/13/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder that impairs mainly the memory and cognitive function in elderly. Extracellular beta amyloid deposition and intracellular tau hyperphosphorylation are the two pathological events that are thought to cause neuronal dysfunction in AD. Since the detailed mechanisms that underlie the pathogenesis of AD are still not clear, the current treatments are those drugs that can alleviate the symptoms of AD patients. Recent studies have indicated that these symptom-reliving drugs also have the ability of regulating amyloid precursor protein processing and tau phosphorylation. Thus the pharmacological mechanism of these drugs may be too simply-evaluated. This review summarizes the current status of AD therapy and some potential preclinical considerations that target beta amyloid and tau protein are also discussed.
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Affiliation(s)
- Yang Hong-Qi
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou , Henan Province, 450003, People's Republic of China
| | - Sun Zhi-Kun
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou , Henan Province, 450003, People's Republic of China
| | - Chen Sheng-Di
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
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Yang HQ, Li X, Yang WM, Feng SM, Ma JJ. Neuroprotective effects of new protein kinase C activator TPPB against Aβ₂₅₋₃₅ induced neurotoxicity in PC12 cells. Neurochem Res 2012; 37:2213-21. [PMID: 22832950 DOI: 10.1007/s11064-012-0846-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 06/09/2012] [Accepted: 07/13/2012] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease (AD) is pathologically characterized by presence of senile plaques in the hippocampus, which are composed mainly of extracellular deposition of a polypeptide known as the beta amyloid, the Aβ. It has been demonstrated on numerous occasions that it was the deposition and aggregation of this Aβ peptide that cause neuronal dysfunction and even finally, the dementia. Lowering the deposition of Aβ or decreasing its neurotoxicity has long been one of the purposes of AD therapy. In previous study, we reported that protein kinase C (PKC) activator TPPB could regulate APP processing by increasing α-secretase activity. In this study we further investigated the potential neuroprotective effect of TPPB against Aβ(25-35)-induced neurotoxicity in PC12 cells. The results indicated that TPPB at concentration of 1 μM could antagonize Aβ(25-35) induced cell damage as evidenced by MTT assays, LDH release and by morphological changes. Furthermore, the neuroprotection in cell viability can be blocked by inhibitors of PKC, Akt and MAPK. The experiment also indicated that TPPB could increase the phosphorylation of Akt, PKC, MARCKS and MAPK, which were inhibited by Aβ(25-35) treatment. Finally, TPPB inhibited the activation of caspase-3 induced by Aβ(25-35). Taken together, the experiment here implies that TPPB has a role against Aβ(25-35)-induced neurotoxicity in PC12 cells and may suggest its therapeutic potential in AD.
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Affiliation(s)
- Hong-Qi Yang
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou 450003, Henan Province, People's Republic of China.
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Neuroprotective profile of the multitarget drug rasagiline in Parkinson's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 100:127-49. [DOI: 10.1016/b978-0-12-386467-3.00007-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Rasagiline: A novel anti-Parkinsonian monoamine oxidase-B inhibitor with neuroprotective activity. Prog Neurobiol 2010; 92:330-44. [DOI: 10.1016/j.pneurobio.2010.06.008] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 06/10/2010] [Accepted: 06/14/2010] [Indexed: 11/17/2022]
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Yang HQ, Sun ZK, Ba MW, Xu J, Xing Y. Involvement of protein trafficking in deprenyl-induced alpha-secretase activity regulation in PC12 cells. Eur J Pharmacol 2009; 610:37-41. [PMID: 19324034 DOI: 10.1016/j.ejphar.2009.03.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 03/04/2009] [Accepted: 03/15/2009] [Indexed: 11/29/2022]
Abstract
Deprenyl is a selective B-type monoamine oxidase inhibitor and a neuroprotective agent that has been used to slow the progress of Alzheimer's disease for many years. We previously demonstrated that deprenyl could stem amyloid precursor protein processing (APP) toward the non-amyloidogenic pathway through mitogen activated protein kinase (MAPK) and protein kinase C (PKC)-dependent signaling pathways [Yang, H.Q., Ba, M.W., Ren, R.J., Zhang, Y.H., Ma, J.F., Pan, J., Lu, G.Q., Chen, S.D., 2007a. Mitogen activated protein kinase and protein kinase C mediated promotion of sAPPalpha by deprenyl. Neurochem. Int. 50, 74-82.]. The experiment here further showed that deprenyl could increase alpha-secretase activity in a dose-dependent manner in PC12 cells. Deprenyl increased alpha-secretase activity can be partially blocked by pretreatment with brefeldin A, an intracellular protein transport inhibitor, suggesting involvement of protein trafficking in deprenyl regulated alpha-secretase activity. In accordance with this, the experiment showed that brefeldin A also decreased sAPPalpha release induced by deprenyl. Deprenyl promoted ADAM10 transported to the membrane fraction, and this effect was blocked by pretreatment with brefeldin A. The immunocytochemistry staining revealed that deprenyl promoted colocalization of ADAM10 with PKCalpha and PKCepsilon isoforms. These data suggest a novel pharmacological mechanism in which deprenyl increased alpha-secretase activity via protein trafficking related mechanism.
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Affiliation(s)
- Hong-Qi Yang
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou 450003, Henan Province, People's Republic of China
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Sun ZK, Yang HQ, Pan J, Zhen H, Wang ZQ, Chen SD, Ding JQ. Protective effects of erythropoietin on tau phosphorylation induced by beta-amyloid. J Neurosci Res 2008; 86:3018-27. [PMID: 18512763 DOI: 10.1002/jnr.21745] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neuropathological studies have demonstrated that the presence of neurofibrillary tangles (NFTs) is one of the most prominent pathologic characteristics of Alzheimer's disease (AD). The microtubule-associated protein tau is the major component of NFTs, and its abnormal hyperphosphorylation leads to the destabilization of microtubules, impaired axonal transport, and eventual death of the neurons. The hematopoietic cytokine erythropoietin (Epo) is now considered as a viable agent with regard to central nervous system injury in a variety of cellular systems. Here we report that Epo prevented tau hyperphosphorylation in SH-SY5Y cells exposed to the beta-amyloid peptide and that this effect may depend on the PI3K/Akt-GSK-3beta pathway. This study provides new molecular insight into the neuroprotective effect of Epo and suggests its possible therapeutic role in the management of AD.
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Affiliation(s)
- Zhi-Kun Sun
- Department of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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Kazmierczak A, Strosznajder JB, Adamczyk A. alpha-Synuclein enhances secretion and toxicity of amyloid beta peptides in PC12 cells. Neurochem Int 2008; 53:263-9. [PMID: 18804502 DOI: 10.1016/j.neuint.2008.08.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 08/11/2008] [Accepted: 08/21/2008] [Indexed: 01/10/2023]
Abstract
alpha-Synuclein is the fundamental component of Lewy bodies which occur in the brain of 60% of sporadic and familial Alzheimer's disease patients. Moreover, a proteolytic fragment of alpha-synuclein, the so-called non-amyloid component of Alzheimer's disease amyloid, was found to be an integral part of Alzheimer's dementia related plaques. However, the role of alpha-synuclein in pathomechanism of Alzheimer's disease remains elusive. In particular, the relationship between alpha-synuclein and amyloid beta is unknown. In the present study we showed the involvement of alpha-synuclein in amyloid beta secretion and in the mechanism of amyloid beta evoked mitochondria dysfunction and cell death. Rat pheochromocytoma PC12 cells transfected with amyloid beta precursor protein bearing Swedish double mutation (APPsw) and control PC12 cells transfected with empty vector were used in this study. alpha-Synuclein (10microM) was found to increase by twofold amyloid beta secretion from control and APPsw PC12 cells. Moreover, alpha-synuclein decreased the viability of PC12 cells by about 50% and potentiated amyloid beta toxicity leading to mitochondrial dysfunction and caspase-dependent programmed cell death. Inhibitor of caspase-3 (Z-DEVD-FMK, 100microM), and a mitochondrial permeability transition pore blocker, cyclosporine A (2microM) protected PC12 cells against alpha-synuclein or amyloid beta evoked cell death. In contrast Z-DEVD-FMK and cyclosporine A were ineffective in APPsw cells containing elevated amount of amyloid beta treated with alpha-synuclein. It was found that the inhibition of neuronal and inducible nitric oxide synthase reversed the toxic effect of alpha-synuclein in control but not in APPsw cells. Our results indicate that alpha-synuclein enhances the release and toxicity of amyloid beta leading to nitric oxide mediated irreversible mitochondria dysfunction and caspase-dependent programmed cell death.
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Affiliation(s)
- Anna Kazmierczak
- Medical Research Center, Polish Academy of Sciences, Department of Cellular Signaling, Pawińskiego 5 str., 02-106 Warsaw, Poland.
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Marks N, Berg MJ. Neurosecretases provide strategies to treat sporadic and familial Alzheimer disorders. Neurochem Int 2008; 52:184-215. [PMID: 17719698 DOI: 10.1016/j.neuint.2007.06.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 06/05/2007] [Indexed: 12/30/2022]
Abstract
Recent discoveries on neurosecretases and their trafficking to release fibril-forming neuropeptides or other products, are of interest to pathology, cell signaling and drug discovery. Nomenclature arose from the use of amyloid precursor protein (APP) as a prototypic type-1 substrate leading to the isolation of beta-secretase (BACE), multimeric complexes (gamma-secretase, gamma-SC) for intramembranal cleavage, and attributing a new function to well-characterized metalloproteases of the ADAM family (alpha-secretase) for normal APP turnover. While purified alpha/beta-secretases facilitate drug discovery, gamma-SC presents greater challenges for characterization and mechanisms of catalysis. The review comments on links between mutation or polymorphisms in relation to enzyme mechanisms and disease. The association between lipoprotein receptor LRP11 variants and sporadic Alzheimer's disease (SAD) offers scope to integrate components of pre- and post-Golgi membranes, or brain clathrin-coated vesicles within pathways for trafficking as targets for intervention. The presence of APP and metabolites in brain clathrin-coated vesicles as significant cargo with lipoproteins and adaptors focuses attention as targets for therapeutic intervention. This overview emphasizes the importance to develop new therapies targeting neurosecretases to treat a major neurological disorder that has vast economic and social implications.
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Affiliation(s)
- Neville Marks
- Center for Neurochemistry, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, United States.
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Amyloid-beta peptide binds to microtubule-associated protein 1B (MAP1B). Neurochem Int 2007; 52:1030-6. [PMID: 18079022 DOI: 10.1016/j.neuint.2007.10.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Revised: 10/25/2007] [Accepted: 10/29/2007] [Indexed: 01/17/2023]
Abstract
Extracellular and intraneuronal formation of amyloid-beta aggregates have been demonstrated to be involved in the pathogenesis of Alzheimer's disease. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of targets have deleterious effects on cellular functions. In the present study we have shown for the first time that amyloid-beta 1-42 bound to a peptide comprising the microtubule binding domain of the heavy chain of microtubule-associated protein 1B by the screening of a human brain cDNA library expressed on M13 phage. This interaction may explain, in part, the loss of neuronal cytoskeletal integrity, impairment of microtubule-dependent transport and synaptic dysfunction observed previously in Alzheimer's disease.
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Liron T, Seraya CB, Ish-Shalom M, Souroujon MC, Neumann D. Overexpression of amyloid precursor protein reduces epsilon protein kinase C levels. Neuroscience 2007; 146:152-9. [PMID: 17321053 DOI: 10.1016/j.neuroscience.2007.01.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 12/12/2006] [Accepted: 01/07/2007] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is characterized by extracellular deposits of amyloid beta peptide (Abeta), a peptide that is generated upon proteolytic cleavage of amyloid precursor protein (APP). The events leading to the development of AD and their sequence are not yet fully understood. Protein kinase C (PKC) has been suggested to have a significant role in controlling neuronal degeneration and in the aberrant signal transduction taking place in AD. Several studies document a deficit in PKC levels and activity in brains of AD patients when compared with those of normal controls. Such a decrease in PKC could have serious implications since certain PKC isozymes were shown to drive the APP proteolytic cleavage into a non-amyloidogenic pathway. Reduced levels of distinct PKC isozymes could thus contribute to driving APP processing toward an amyloidogenic pathway. The direct cause for the down-regulation of PKC in AD brains is still unknown. In that respect, we tested in this study whether APP may play a role in PKC reduction. We show in three different cell lines (CHO, COS and BOSC) that overexpression of APP leads to decreased PKC levels. This decrease was found to be specific for the epsilon PKC isozyme whereas the levels of delta, alpha and conventional PKC remained unchanged. Furthermore, we observed this decrease for both active, membrane-associated and inactive, cytosolic epsilon PKC. APP-driven decrease in epsilon PKC is most likely mediated by a factor in the culture medium, since transfer of medium from cultured cells overexpressing APP to naïve, non-overexpressing cells, has also led to the selective decrease in epsilon PKC levels. Taken together, our results suggest that APP expression levels may play a role in the decrease of epsilon PKC levels in AD brains and could thus affect the responsiveness of AD brain tissues to growth factors and neurotransmitters.
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Affiliation(s)
- T Liron
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv, Israel
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