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Alalwany RH, Hawtrey T, Morgan K, Morris JC, Donaldson LF, Bates DO. Vascular endothelial growth factor isoforms differentially protect neurons against neurotoxic events associated with Alzheimer's disease. Front Mol Neurosci 2023; 16:1181626. [PMID: 37456522 PMCID: PMC10349181 DOI: 10.3389/fnmol.2023.1181626] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/16/2023] [Indexed: 07/18/2023] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia, the chronic and progressive deterioration of memory and cognitive abilities. AD can be pathologically characterised by neuritic plaques and neurofibrillary tangles, formed by the aberrant aggregation of β-amyloid and tau proteins, respectively. We tested the hypothesis that VEGF isoforms VEGF-A165a and VEGF-A165b, produced by differential splice site selection in exon 8, could differentially protect neurons from neurotoxicities induced by β-amyloid and tau proteins, and that controlling expression of splicing factor kinase activity could have protective effects on AD-related neurotoxicity in vitro. Using oxidative stress, β-amyloid, and tau hyperphosphorylation models, we investigated the effect of VEGF-A splicing isoforms, previously established to be neurotrophic agents, as well as small molecule kinase inhibitors, which selectively inhibit SRPK1, the major regulator of VEGF splicing. While both VEGF-A165a and VEGF-A165b isoforms were protective against AD-related neurotoxicity, measured by increased metabolic activity and neurite outgrowth, VEGF-A165a was able to enhance neurite outgrowth but VEGF-A165b did not. In contrast, VEGF-A165b was more effective than VEGF-A165a in preventing neurite "dieback" in a tau hyperphosphorylation model. SRPK1 inhibition was found to significantly protect against neurite "dieback" through shifting AS of VEGFA towards the VEGF-A165b isoform. These results indicate that controlling the activities of the two different isoforms could have therapeutic potential in Alzheimer's disease, but their effect may depend on the predominant mechanism of the neurotoxicity-tau or β-amyloid.
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Affiliation(s)
- Roaa H. Alalwany
- Tumour and Vascular Biology Laboratories, Division of Cancer and Stem Cells, Centre for Cancer Sciences, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
| | - Tom Hawtrey
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia
| | - Kevin Morgan
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jonathan C. Morris
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia
| | - Lucy F. Donaldson
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - David O. Bates
- Tumour and Vascular Biology Laboratories, Division of Cancer and Stem Cells, Centre for Cancer Sciences, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
- Pan African Cancer Research Institute, University of Pretoria, Pretoria, South Africa
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Lantz MJ, Roberts AM, Delgado DD, Nichols RA. The neuroprotective N-terminal amyloid-β core hexapeptide reverses reactive gliosis and gliotoxicity in Alzheimer's disease pathology models. J Neuroinflammation 2023; 20:129. [PMID: 37245024 DOI: 10.1186/s12974-023-02807-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 05/16/2023] [Indexed: 05/29/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by accumulation of extracellular amyloid beta (Aβ) and intracellular neurofibrillary tangles, leading to chronic activation of astrocytes and microglia and persistent neuroinflammation. Aβ-linked activation of microglia and astrocytes leads to increased intracellular calcium and production of proinflammatory cytokines, impacting the progression of neurodegeneration. An N-terminal Aβ fragment (Aβ1-15) and a shorter hexapeptide core sequence within the N-Aβ fragment (N-Aβcore: Aβ10-15) have previously been shown to protect against Aβ-induced mitochondrial dysfunction, oxidative stress and apoptosis in neurons and rescue synaptic and spatial memory deficits in an APP/PSEN1 mouse model. Here, we hypothesized that the N-Aβ fragment and N-Aβcore are protective against Aβ-induced gliotoxicity, promoting a neuroprotective environment and potentially alleviating the characteristically persistent neuroinflammation present in AD. METHODS We treated ex vivo organotypic brain slice cultures from an aged familial AD mouse model, 5xFAD, with the N-Aβcore and used immunocytochemistry to assess the impact on astrogliosis and microgliosis and alterations in synaptophysin-positive puncta engulfed by microglia. Isolated neuron/glia cultures, mixed glial cultures or a microglial cell line were treated with oligomeric human Aβ at concentrations mimicking the pathogenic concentrations (μM) observed in AD in the absence or presence of the non-toxic N-terminal Aβ fragments. Resultant changes in synaptic density, gliosis, oxidative stress, mitochondrial dysfunction, apoptosis, and the expression and release of proinflammatory markers were then determined. RESULTS We demonstrate that the N-terminal Aβ fragments mitigated the phenotypic switch leading to astrogliosis and microgliosis induced by pathological concentrations of Aβ in mixed glial cultures and organotypic brain slice cultures from the transgenic 5xFAD mouse model, while protecting against Aβ-induced oxidative stress, mitochondrial dysfunction and apoptosis in isolated astrocytes and microglia. Moreover, the addition of the N-Aβcore attenuated the expression and release of proinflammatory mediators in microglial cells activated by Aβ and rescued microglia-mediated loss of synaptic elements induced by pathological levels of Aβ. CONCLUSIONS Together, these findings indicate the protective functions of the N-terminal Aβ fragments extend to reactive gliosis and gliotoxicity induced by Aβ, by preventing or reversing glial reactive states indicative of neuroinflammation and synaptic loss central to AD pathogenesis.
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Affiliation(s)
- Megan J Lantz
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Alyssa M Roberts
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Donovan D Delgado
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Robert A Nichols
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, HI, USA.
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Salehi A, Ghanadian M, Zolfaghari B, Jassbi AR, Fattahian M, Reisi P, Csupor D, Khan IA, Ali Z. Neuropharmacological Potential of Diterpenoid Alkaloids. Pharmaceuticals (Basel) 2023; 16:ph16050747. [PMID: 37242531 DOI: 10.3390/ph16050747] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/28/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
This study provides a narrative review of diterpenoid alkaloids (DAs), a family of extremely important natural products found predominantly in some species of Aconitum and Delphinium (Ranunculaceae). DAs have long been a focus of research attention due to their numerous intricate structures and diverse biological activities, especially in the central nervous system (CNS). These alkaloids originate through the amination reaction of tetra or pentacyclic diterpenoids, which are classified into three categories and 46 types based on the number of carbon atoms in the backbone structure and structural differences. The main chemical characteristics of DAs are their heterocyclic systems containing β-aminoethanol, methylamine, or ethylamine functionality. Although the role of tertiary nitrogen in ring A and the polycyclic complex structure are of great importance in drug-receptor affinity, in silico studies have emphasized the role of certain sidechains in C13, C14, and C8. DAs showed antiepileptic effects in preclinical studies mostly through Na+ channels. Aconitine (1) and 3-acetyl aconitine (2) can desensitize Na+ channels after persistent activation. Lappaconitine (3), N-deacetyllapaconitine (4), 6-benzoylheteratisine (5), and 1-benzoylnapelline (6) deactivate these channels. Methyllycaconitine (16), mainly found in Delphinium species, possesses an extreme affinity for the binding sites of α7 nicotinic acetylcholine receptors (nAChR) and contributes to a wide range of neurologic functions and the release of neurotransmitters. Several DAs such as bulleyaconitine A (17), (3), and mesaconitine (8) from Aconitum species have a drastic analgesic effect. Among them, compound 17 has been used in China for decades. Their effect is explained by increasing the release of dynorphin A, activating the inhibitory noradrenergic neurons in the β-adrenergic system, and preventing the transmission of pain messages by inactivating the Na+ channels that have been stressed. Acetylcholinesterase inhibitory, neuroprotective, antidepressant, and anxiolytic activities are other CNS effects that have been investigated for certain DAs. However, despite various CNS effects, recent advances in developing new drugs from DAs were insignificant due to their neurotoxicity.
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Affiliation(s)
- Arash Salehi
- Department of Pharmacognosy, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran
| | - Mustafa Ghanadian
- Department of Pharmacognosy, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran
- Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran
| | - Behzad Zolfaghari
- Department of Pharmacognosy, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran
| | - Amir Reza Jassbi
- Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz 71348-14336, Iran
| | - Maryam Fattahian
- Department of Pharmacognosy, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran
| | - Parham Reisi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81745-33871, Iran
| | - Dezső Csupor
- Institute of Clinical Pharmacy, Faculty of Pharmacy, University of Szeged, 6720 Szeged, Hungary
| | - Ikhlas A Khan
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
| | - Zulfiqar Ali
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
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Collins AE, Saleh TM, Kalisch BE. VANL-100 Attenuates Beta-Amyloid-Induced Toxicity in SH-SY5Y Cells. Int J Mol Sci 2022; 24:ijms24010442. [PMID: 36613883 PMCID: PMC9820495 DOI: 10.3390/ijms24010442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/16/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Antioxidants are being explored as novel therapeutics for the treatment of neurodegenerative diseases such as Alzheimer's disease (AD) through strategies such as chemically linking antioxidants to synthesize novel co-drugs. The main objective of this study was to assess the cytoprotective effects of the novel antioxidant compound VANL-100 in a cellular model of beta-amyloid (Aβ)-induced toxicity. The cytotoxic effects of Aβ in the presence and absence of all antioxidant compounds were measured using the 3-(4,5-dimethylthiazol-2-yl)2-5-diphenyl-2H-tetrazolium bromide (MTT) assay in SH-SY5Y cells in both pre-treatment and co-treatment experiments. In pre-treatment experiments, VANL-100, or one of its parent compounds, naringenin (NAR), alpha-lipoic acid (ALA), or naringenin + alpha-lipoic acid (NAR + ALA), was administrated 24 h prior to an additional 24-h incubation with 20 μM non-fibril or fibril Aβ25-35. Co-treatment experiments consisted of simultaneous treatment with Aβ and antioxidants. Pre-treatment and co-treatment with VANL-100 significantly attenuated Aβ-induced cell death. There were no significant differences between the protective effects of VANL-100, NAR, ALA, and NAR + ALA with either form of Aβ, or in the effect of VANL-100 between 24-h pre-treatment and co-treatment. These results demonstrate that the novel co-drug VANL-100 is capable of eliciting cytoprotective effects against Aβ-induced toxicity.
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Khonsari F, Heydari M, Sharifzadeh M, Valizadeh H, Dinarvand R, Atyabi F. Transferrin decorated-nanostructured lipid carriers (NLCs) are a promising delivery system for rapamycin in Alzheimer's disease: An in vivo study. BIOMATERIALS ADVANCES 2022; 137:212827. [PMID: 35929260 DOI: 10.1016/j.bioadv.2022.212827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/06/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Alzheimer's disease (AD), the most common neurodegenerative disorder, is characterized by progressive cognitive impairment and memory loss. The mammalian target of rapamycin (mTOR) signaling pathway could regulate learning and memory. The effect of rapamycin (Rapa) on mTOR activity could slow or prevent the progression of AD by affecting various essential cellular processes. Previously, we prepared transferrin (Tf) decorated-nanostructured lipid carriers (NLCs) for rapamycin (150 ± 9 nm) to protect the drug from chemical and enzymatic degradation and for brain targeted delivery of rapamycin. Herein, the effect of Tf-NLCs compared to untargeted anionic-NLCs and free rapamycin, were studied in amyloid beta (Aβ) induced rat model of AD. Behavioral test revealed that the Rapa Tf-NLCs were able to significantly improve the impaired spatial memory induced by Aβ. Histopathological studies of hippocampus also showed neural survival in Rapa Tf-NLCs treated group. The immunosuppressive, and delayed wound healing adverse effects in the rapamycin solution treated group were abolished by incorporating the drug into NLCs. The Aβ induced oxidative stress was also reduced by Rapa Tf-NLCs. Molecular studies on the level of Aβ, autophagy (LC3) and apoptotic (caspase-3) markers, and mTOR activity revealed that the Rapa Tf-NLCs decreased the Aβ level and suppressed the toxic effects of Aβ plaques by modulating the mTOR activity and autophagy, and decreasing the apoptosis level. As a conclusion, the designed Tf-NLCs could be an appropriate and a safe brain delivery system for rapamycin and make this drug more efficient in AD for improving memory and neuroprotection.
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Affiliation(s)
- Fatemeh Khonsari
- Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Heydari
- Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sharifzadeh
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
| | - Hadi Valizadeh
- Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Rassoul Dinarvand
- Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; School of Pharmacy, De Mont Fort University, Leicester, UK
| | - Fatemeh Atyabi
- Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
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Baicalin Alleviates Thrombin-Induced Inflammation in Vascular Smooth Muscle Cells. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5799308. [PMID: 35097121 PMCID: PMC8799346 DOI: 10.1155/2022/5799308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/27/2021] [Indexed: 11/26/2022]
Abstract
Atherosclerosis (AS) is a chronic inflammatory disease of the arterial intima. As AS represents the most common type of vascular disease, it affects millions of individuals and is a source of high morbidity and mortality rates worldwide. Overwhelming evidence indicates that AS-related inflammation is mediated by proinflammatory cytokines, chemokines, adhesion molecules and inflammatory signaling pathways, with each of these factors being shown to play critical roles during the entire progression of AS. While a number of drugs have been approved for use in the treatment of AS, their benefits are modest, which underscores the urgency for the development of new drug therapies. In part, these deficits in effective drugs can be attributable to the lack of a clear understanding of the molecular mechanisms of AS. In this study, we investigate the capacity for thrombin to trigger inflammation and induce cell proliferation in vascular smooth muscle cells (VSMCs). We then assessed the effects of baicalin and its potential mechanisms on VSMC inflammation as induced by thrombin. Baicalin, which is a natural bioactive compound of S. baicalensis Georgi (SBG), exerted a protective effect against thrombin-induced VSMC inflammation as resulting from the upregulation of PAR-1. This protection as exerted by baicalin appears to reside in its capacity to produce an inhibitory effect on the thrombin-induced activation of the ERK1/2 pathway. These findings suggest that baicalin may be a promising candidate for the treatment of atherosclerosis.
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Comparison of bovine serum albumin glycation by ribose and fructose in vitro and in vivo. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166283. [PMID: 34601015 DOI: 10.1016/j.bbadis.2021.166283] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/24/2021] [Accepted: 09/22/2021] [Indexed: 12/25/2022]
Abstract
Advanced glycation end products (AGEs) play a critical pathogenic role in the development of diabetic complications. Recent studies have shown that diabetes is associated with not only abnormal glucose metabolism but also abnormal ribose and fructose metabolism, although glucose is present at the highest concentration in humans. The glycation ability and contribution of ribose and fructose to diabetic complications remain unclear. Here, the glycation ability of ribose, fructose and glucose under a mimic physiological condition, in which the concentration of ribose or fructose was one-fiftieth that of glucose, was compared. Bovine serum albumin (BSA) was used as the working protein in our experiments. Ribose generated more AGEs and was markedly more cytotoxic to SH-SY5Y cells than fructose. The first-order rate constant of ribose glycation was found to be significantly greater than that of fructose glycation. LC-MS/MS analysis revealed 41 ribose-glycated Lys residues and 12 fructose-glycated residues. Except for the shared Lys residues, ribose reacted selectively with 17 Lys, while no selective Lys was found in fructose-glycated BSA. Protein conformational changes suggested that ribose glycation may induce BSA into amyloid-like monomers compared with fructose glycation. The levels of serum ribose were correlated positively with glycated serum protein (GSP) and diabetic duration in type 2 diabetes mellitus (T2DM), respectively. These results indicate that ribose has a greater glycation ability than fructose, while ribose largely contributes to the production of AGEs and provides a new insight to understand in the occurrence and development of diabetes complications.
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Mohamed RA, Abdallah DM, El-brairy AI, Ahmed KA, El-Abhar HS. Palonosetron/Methyllycaconitine Deactivate Hippocampal Microglia 1, Inflammasome Assembly and Pyroptosis to Enhance Cognition in a Novel Model of Neuroinflammation. Molecules 2021; 26:5068. [PMID: 34443654 PMCID: PMC8401912 DOI: 10.3390/molecules26165068] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 12/30/2022] Open
Abstract
Since westernized diet-induced insulin resistance is a risk factor in Alzheimer's disease (AD) development, and lipopolysaccharide (LPS) coexists with amyloid β (Aβ)1-42 in these patients, our AD novel model was developed to resemble sporadic AD by injecting LPS into high fat/fructose diet (HFFD)-fed rats. The neuroprotective potential of palonosetron and/or methyllycaconitine, 5-HT3 receptor and α7 nAChR blockers, respectively, was evaluated after 8 days of daily administration in HFFD/LPS rats. All regimens improved histopathological findings and enhanced spatial memory (Morris Water Maze); however, palonosetron alone or with methyllycaconitine promoted animal performance during novel object recognition tests. In the hippocampus, all regimens reduced the expression of glial fibrillary acidic protein and skewed microglia M1 to M2 phenotype, indicated by the decreased M1 markers and the enhanced M2 related parameters. Additionally, palonosetron and its combination regimen downregulated the expression of ASC/TMS1, as well as levels of inflammasome downstream molecules and abated cleaved caspase-1, interleukin (IL)-1β, IL-18 and caspase-11. Furthermore, ACh and 5-HT were augmented after being hampered by the insult. Our study speculates that blocking 5-HT3 receptor using palonosetron overrides methyllycaconitine to combat AD-induced neuroinflammation and inflammasome cascade, as well as to restore microglial function in a HFFD/LPS novel model for sporadic AD.
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Affiliation(s)
- Reem A. Mohamed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October University for Modern Sciences and Arts, 26 July Mehwar Road Intersection with Wahat Road, 6th of October City, Giza 12451, Egypt; (R.A.M.); (A.I.E.-b.)
| | - Dalaal M. Abdallah
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Κasr El-Aini Str., Cairo 11562, Egypt;
| | - Amany I. El-brairy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October University for Modern Sciences and Arts, 26 July Mehwar Road Intersection with Wahat Road, 6th of October City, Giza 12451, Egypt; (R.A.M.); (A.I.E.-b.)
| | - Kawkab A. Ahmed
- Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt;
| | - Hanan S. El-Abhar
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Κasr El-Aini Str., Cairo 11562, Egypt;
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Weng G, Zhou B, Liu T, Huang Z, Huang S. Tetramethylpyrazine Improves Cognitive Function of Alzheimer's Disease Mice by Regulating SSTR4 Ubiquitination. DRUG DESIGN DEVELOPMENT AND THERAPY 2021; 15:2385-2399. [PMID: 34103899 PMCID: PMC8179737 DOI: 10.2147/dddt.s290030] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/12/2021] [Indexed: 01/08/2023]
Abstract
Purpose Many researches have investigated the functions of tetramethylpyrazine (TMP) in Alzheimer's disease (AD). This study aimed to discuss the underlying mechanism of TMP in AD mice. Methods TMP (200 mg/kg) was administered to 6-month-old APP/PS1 transgenic mice, and behavioral changes and hippocampal nerve injury in AD mice were detected. Apoptosis and autophagy-related protein levels were detected. Changes in gene expression before and after TMP treatment were compared using transcriptome sequencing. The effects of Cullin 4B (CUL4B) overexpression and somatostatin receptor 4 (SSTR4) silencing on AD symptoms and SSTR4 ubiquitination in APP/PS1 mice were observed. SH-SY5Y and PC12 cells were treated with 25 μmol/L Aβ25-35 and TMP to observe cell viability, apoptosis, and autophagy. Cell viability and apoptosis were measured again after treatment with proteasome inhibitor MG132 or lysosomal inhibitor 3-mA. Results TMP treatment improved the behavioral cognition of APP/PS1 mice and improved the neuronal apoptosis and damage in brain tissue. CUL4B was significantly upregulated in APP/PS1 mouse brain tissue, and SSRT4 protein was downregulated, and the levels of CUL4B and SSRT4 were negatively correlated. TMP treatment downregulated CUL4B, inhibited SSRT4 ubiquitination and upregulated SSRT4 protein level in APP/PS1 mouse brain tissue, while CUL4B overexpression or SSRT4 silencing reversed the effect of TMP. TMP and MG132 improved the decreased activity, increased apoptosis and increased SSRT4 protein in SH-SY5Y and PC12 cells treated with Aβ25-35, but not 3-mA. CUL4B overexpression promoted the ubiquitination of SSTR4 in cells, which partially reversed the effect of TMP. Conclusion TMP could improve the cognitive ability of AD mice by inhibiting CUL4B expression and the ubiquitination degradation of SSTR, and alleviating neuronal apoptosis and injury. This study may offer a new therapeutic option for AD treatment.
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Affiliation(s)
- Guohu Weng
- Department of Encephalopathy, Hainan Provincial Hospital of Traditional Chinese Medicine, Haikou, 570203, Hainan, People's Republic of China
| | - Bo Zhou
- Department of Cardiology, Hainan Provincial Hospital of Traditional Chinese Medicine, Haikou, 570203, Hainan, People's Republic of China
| | - Tao Liu
- Department of Neurology, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, 570311, Hainan, People's Republic of China
| | - Zhengxin Huang
- Department of Cardiology, Hainan Provincial Hospital of Traditional Chinese Medicine, Haikou, 570203, Hainan, People's Republic of China
| | - Shixiong Huang
- Department of Neurology, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, 570311, Hainan, People's Republic of China
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Das M, Devi KP. Dihydroactinidiolide regulates Nrf2/HO-1 expression and inhibits caspase-3/Bax pathway to protect SH-SY5Y human neuroblastoma cells from oxidative stress induced neuronal apoptosis. Neurotoxicology 2021; 84:53-63. [PMID: 33617922 DOI: 10.1016/j.neuro.2021.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/21/2020] [Accepted: 02/17/2021] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) etiology has been studied for a long time and it is found to be multifaceted involving the accumulation of amyloid β and tau protein. Oxidative stress is an early event in AD associated neurodegeneration provoking neuronal death through mitochondrial dysfunction and activation of caspase-3. Therefore we tested the efficacy of dihydroactinidiolide (DHAc), a monoterpene lactone against the oxidative load involved in AD like pathological conditions induced by sodium dithionite, glutamate, amyloid β and colchicine in SH-SY5Y cells. Some of the indicators of neurotoxicity like acetylcholinesterase activity, intracellular reactive oxygen species (ROS), nitrite content, lipid peroxidation, protein carbonylation, nuclear and membrane damage were found to be significantly high in the toxicant treated cells when compared to the control cells while DHAc pretreatment significantly restored the toxicant induced neuronal damage signatures. Caspase-3 activity was found to be increased in the toxicant treated cells while DHAc significantly reduced it. Western blotting and RT-PCR revealed that DHAc significantly increased anti-apoptotic Bcl-2 expression and mRNA levels of Nrf2 and HO-1. Therefore DHAc was found to protect SH-SY5Y cells from neurotoxicant induced oxidative stress and apoptosis by regulating cellular antioxidant defenses and apoptosis related genes.
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Affiliation(s)
- Mamali Das
- Department of Biotechnology, Alagappa University (Science Campus), Karaikudi, 630003, India
| | - Kasi Pandima Devi
- Department of Biotechnology, Alagappa University (Science Campus), Karaikudi, 630003, India.
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11
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Wiatrak B, Balon K. Protective Activity of Aβ on Cell Cultures (PC12 and THP-1 after Differentiation) Preincubated with Lipopolysaccharide (LPS). Mol Neurobiol 2020; 58:1453-1464. [PMID: 33188619 PMCID: PMC7932962 DOI: 10.1007/s12035-020-02204-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/04/2020] [Indexed: 02/08/2023]
Abstract
Amyloid-β (Aβ), the influence of which is considered the pathomechanism of Alzheimer’s disease, is also present in healthy people. The microbiome’s impact is also taken into account, where bacterial lipopolysaccharide (LPS) activates inflammatory processes and stimulates microglia via TLRs. Molecules of bacterial origin can co-create senile plaques with Aβ. This study evaluated the activity of physiological Aβ concentrations on neuronal and microglial cells after preincubation with LPS. Two cell lines were used in the study: PC12 cells differentiated with NGF and THP-1 cells differentiated with phorbol 12-myristate 13-acetate (PMA). Cells were incubated with LPS at concentrations of 1–100 μM for 24 h and then with Aβ25–35 at a concentration of 0.001 μM or 1.0 μM for another 24 h. The viability of the culture and free oxygen radicals and the number of DNA strand breaks in both cell lines were evaluated. Additionally, for PC12 cells, neural features were assessed. Stimulation of repair processes in the presence of Aβ was observed for both studied cell lines. There was a decrease in free radical level and DNA damage number compared to control cultures (cells treated with LPS and without Aβ). The neurotrophic activity of Aβ was observed—the effect on neurites’ growth even after the preincubation of PC12 cells with LPS. At the lowest concentration of LPS used, the increase in neurite length was about 50% greater than in the negative control. At low concentrations, Aβ has a protective effect on neuron-like PC12 cells pretreated with LPS.
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Affiliation(s)
- Benita Wiatrak
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345, Wrocław, Poland. .,Department of Basic Medical Sciences, Wroclaw Medical University, Wrocław, Poland.
| | - Katarzyna Balon
- Department of Basic Medical Sciences, Wroclaw Medical University, Wrocław, Poland
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Wu L, Zheng Q, Guo YY, Zhang KN, Luo J, Xiao S, Li WJ, Yang M. Effect of Zhenxin Xingshui Yizhi Fang on Aβ 25-35 induced expression of related transporters in HBMEC cell model. JOURNAL OF ETHNOPHARMACOLOGY 2020; 260:112783. [PMID: 32240783 DOI: 10.1016/j.jep.2020.112783] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 03/20/2020] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Aβ (β-amyloid) deposition and abnormal transport were suggested to be risk factors for Alzheimer's disease (AD). Zhenxin Xingshui Yizhi Fang (XSF), an ancient prescription in traditional Chinese medicine, was first recorded in Qianjin Yifang for treating palpitation, hypnosia, amnesia. It is reported that XSF could improve mice learning memory ability, reduce the deposition of senile plaques in hippocampus of rat brain. In this study, the neuroprotective effect of XSF against Aβ25-35-induced apoptosis in cultured human brain microvascular endothelial cells (HBMEC) and its potential mechanism were investigated. MATERIALS AND METHODS HBMEC cells were treated with Aβ25-35 to established neurotoxic cell model. After that, the cells were treated with 125, 250, 500 μg/mL XSF to observe the protective effect. The viability of HBMEC cells were evaluated by MTT assay, the Aβ25-35-induced apoptosis was characterized by Hoechst-33258 and the activity of cysteinyl aspartate specific proteinase-3. The expression level of Aβ1-42 in cells induced by Aβ25-35 was measured by human Aβ1-42 kit. Protein and mRNA expression levels of advanced glycation end products (RAGE), low density lipoprotein receptor-related protein 1 (LRP1), glucose transporter 1 and 3 (GLUT1 and GLUT3) were assayed by capillary electrophoresis immunoassay and quantitative real-time polymerase chain reaction analyses. RESULTS In Aβ25-35 induced neurotoxic cells, the percentage of apoptotic cells, the concentration of Aβ1-42 and CASPASE-3 activity, protein and mRNA expression levels of RAGE increased significantly, but that of LRP1, GLUT1 and GLUT3 significantly decreased. XSF could inhibit the apoptotic of cells, reduced the concentration of Aβ1-42 and CASPASE-3 expression, downregulate RAGE and upregulate LRP1, GLUT1 and GLUT3 expression. CONCLUSION The results suggest that XSF can reduce the cytotoxicity of HBMEC induced by Aβ25-35, inhibit apoptosis, and regulate the transport of Aβ on BBB and energy metabolism disorder in HBMEC.
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Affiliation(s)
- Ling Wu
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
| | - Qin Zheng
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China.
| | - Yuan-Yuan Guo
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
| | - Ke-Nan Zhang
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
| | - Jun Luo
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
| | - Shuai Xiao
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
| | - Wen-Jing Li
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
| | - Ming Yang
- Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, State Key Lab of Innovation Drug and Efficient Energy-Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, 330004, China
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13
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Yu J, Jin T, Zhang T. Suppression of Long Non-Coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) Potentiates Cell Apoptosis and Drug Sensitivity to Taxanes and Adriamycin in Breast Cancer. Med Sci Monit 2020; 26:e922672. [PMID: 32623440 PMCID: PMC7357251 DOI: 10.12659/msm.922672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/04/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is expressed highly in various types of tumors. Moreover, the tumor-initiating role of MALAT1 has been probed in the context of breast cancer. This study was set to investigate the regulatory role of MALAT1 on the chemosensitivity of breast cancer cells to taxanes (Tax) and adriamycin (Adr). MATERIAL AND METHODS Following the measurement of MALAT1 expression in patients with breast cancer by means of qRT-PCR, the connection between the MALAT1 expression pattern and the prognosis of breast cancer patients as well as the molecular typing of breast cancer patients was analyzed using Kaplan-Meier survival analysis and receiver operating characteristic (ROC) curves. Next, the analysis between the expression of MALAT1 and the clinical symptoms of breast cancer patients was carried out. Subsequently, we generated taxane-resistant MCF-7 cells (MCF-7/Tax) and purchased Adr-resistant MCF-7 cells (MCF-7/Adr). Finally, the proliferation, apoptosis and drug resistance of resistant and parental cells were evaluated after transfection of silencing MALAT1 into these cells. RESULTS MALAT1 was highly expressed in the breast cancer tissues. Moreover, patients with relative overexpression of MALAT1 had worse prognosis. MALAT1 expression was remarkably promoted in MCF-7/Tax and MCF-7/Adr cells, whose sensitivity to Tax and Adr was enhanced following MALAT1 knockdown. CONCLUSIONS MALAT1 was elevated in breast cancer tissues and MCF-7-resistant cells, relative to corresponding controls and downregulation of MALAT1 inhibited the growth and chemoresistance of breast cancer cells to Tax and Adr.
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Affiliation(s)
- Jie Yu
- Department of General Surgery I, Zhuji Central Hospital, Zhuji, Zhejiang, P.R. China
| | - Taobo Jin
- Department of Thyroid and Breast Surgery, Zhuji People’s Hospital, Zhuji, Zhejiang, P.R. China
| | - Tianya Zhang
- Department of Thyroid and Breast Surgery, Zhuji People’s Hospital, Zhuji, Zhejiang, P.R. China
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14
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Cuevas E, Rosas-Hernandez H, Burks SM, Ramirez-Lee MA, Guzman A, Imam SZ, Ali SF, Sarkar S. Amyloid Beta 25-35 induces blood-brain barrier disruption in vitro. Metab Brain Dis 2019; 34:1365-1374. [PMID: 31267346 DOI: 10.1007/s11011-019-00447-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 06/05/2019] [Indexed: 11/27/2022]
Abstract
The amyloid β-peptide (Aβ) is transported across the blood-brain barrier (BBB) by binding with the receptor for advanced glycation end products (RAGE). Previously, we demonstrated that the Aβ fraction 25-35 (Aβ25-35) increases RAGE expression in the rat hippocampus, likely contributing to its neurotoxic effects. However, it is still debated if the interaction of Aβ with RAGE compromises the BBB function in Alzheimer' disease (AD). Here, we evaluated the effects of Aβ25-35 in an established in vitro model of the BBB. Rat brain microvascular endothelial cells (rBMVECs) were treated with 20 μM active Aβ25-35 or the inactive Aβ35-25 (control), for 24 h. Exposure to Aβ25-35 significantly decreased cell viability, increased cellular necrosis, and increased the production of reactive oxygen species (ROS), which triggered a decrease in the enzyme glutathione peroxidase when compared to the control condition. Aβ25-35 also increased BBB permeability by altering the expression of tight junction proteins (decreasing zonula occludens-1 and increasing occludin). Aβ25-35 induced monolayer disruption and cellular disarrangement of the BBB, with RAGE being highly expressed in the zones of disarrangement. Together, these data suggest that Aβ25-35-induces toxicity by compromising the functionality and integrity of the BBB in vitro. Graphical abstract Aβ25-35 induces BBB dysfunction in vitro, wich is likely mediated by OS and ultimately leads to disruption of BBB integrity and cell death.
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Affiliation(s)
- Elvis Cuevas
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
| | - Hector Rosas-Hernandez
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Susan M Burks
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Manuel A Ramirez-Lee
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Aida Guzman
- Escuela Nacional Preparatoria-UNAM, Mexico, Mexico
| | - Syed Z Imam
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Syed F Ali
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Sumit Sarkar
- Division of Neurotoxicology, National Center for Toxicological Research/U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
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15
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Dexmedetomidine prevents septic myocardial dysfunction in rats via activation of α7nAChR and PI3K/Akt- mediated autophagy. Biomed Pharmacother 2019; 120:109231. [PMID: 31546082 DOI: 10.1016/j.biopha.2019.109231] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/13/2019] [Accepted: 07/15/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Dexmedetomidine (Dex) has been shown to elicit cardio-protective effects in sepsis. The aim of this study was to investigate the role of autophagy in the protective effects of Dex and its possible mechanism in vivo and vitro. EXPERIMENTAL APPROACH 6-8-week-old male Wistar rats were performed cecal ligation puncture (CLP) and administered 0.9% saline (CLP group), 50 μg/kg Dex (Dex group), Dex plus chloroquine (20 mg/kg; Dex + CQ group), or 40 μg/kg methyllycaconitin (Dex + MLA group), or 25 μM LY294002 (Dex + LY294002 group). After study, cardiac histology, cardiac function, level of autophagy, cardiomyocytes apoptosis and inflammatory mediators including protein IL-1β, IL-6, and TNF-α were measured. The LPS induced-H9C2 cardiomyocytes were treated with Dex, Dex + CQ and detected for cell apoptosis, autophagy level and cell cycle. KEY RESULTS CLP-induced sepsis resulted in cardiac dysfunction, apoptosis, and inflammatory response. Dex exhibited protective effects on the myocardium by the induction of myocardial autophagy and ameliorated the LPS-induced blockade of autophagic flux in H9C2 cells. CQ was found to significantly inhibit Dex-mediated protection of myocardial apoptosis and inflammation. CLP rats treated with Dex in combination with MLA, an antagonist of α7 nicotinic acetylcholine receptor (α7nAChR), exhibited decreased autophagy and increased inflammation and cell death, identifying α7nAchR was involved in the Dex-mediated pathway. In addition, we found that the PI3K/Akt pathway is involved in Dex-mediated autophagy and convergent with α7nAChR-mediated stimulation of autophagy response. CONCLUSIONS AND IMPLICATIONS For the first time, these data indicate that autophagy is central in Dex-mediated cardio-protection in sepsis. These observations provide the foundation for further study, and may serve as the basis for innovative therapeutic strategies against septic myocardial dysfunction.
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16
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Malishev R, Nandi S, Śmiłowicz D, Bakavayev S, Engel S, Bujanover N, Gazit R, Metzler-Nolte N, Jelinek R. Interactions between BIM Protein and Beta-Amyloid May Reveal a Crucial Missing Link between Alzheimer's Disease and Neuronal Cell Death. ACS Chem Neurosci 2019; 10:3555-3564. [PMID: 31141342 DOI: 10.1021/acschemneuro.9b00177] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Extensive neuronal cell death is among the pathological hallmarks of Alzheimer's disease. While neuron death is coincident with formation of plaques comprising the beta-amyloid (Aβ) peptide, a direct causative link between Aβ (or other Alzheimer's-associated proteins) and cell toxicity is yet to be found. Here we show that BIM-BH3, the primary proapoptotic domain of BIM, a key protein in varied apoptotic cascades of which elevated levels have been found in brain cells of patients afflicted with Alzheimer's disease, interacts with the 42-residue amyloid isoform Aβ42. Remarkably, BIM-BH3 modulated the structure, fibrillation pathway, aggregate morphology, and membrane interactions of Aβ42. In particular, BIM-BH3 inhibited Aβ42 fibril-formation, while it simultaneously enhanced protofibril assembly. Furthermore, we discovered that BIM-BH3/Aβ42 interactions induced cell death in a human neuroblastoma cell model. Overall, our data provide a crucial mechanistic link accounting for neuronal cell death in Alzheimer's disease patients and the participation of both BIM and Aβ42 in the neurotoxicity process.
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Affiliation(s)
- Ravit Malishev
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Sukhendu Nandi
- Inorganic Chemistry I – Bioinorganic Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Dariusz Śmiłowicz
- Inorganic Chemistry I – Bioinorganic Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Shamchal Bakavayev
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Stanislav Engel
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nir Bujanover
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Roi Gazit
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nils Metzler-Nolte
- Inorganic Chemistry I – Bioinorganic Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Raz Jelinek
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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Isomerization of Asp7 in Beta-Amyloid Enhances Inhibition of the α7 Nicotinic Receptor and Promotes Neurotoxicity. Cells 2019; 8:cells8080771. [PMID: 31349637 PMCID: PMC6721525 DOI: 10.3390/cells8080771] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 01/02/2023] Open
Abstract
Cholinergic dysfunction in Alzheimer’s disease (AD) can be mediated by the neuronal α7 nicotinic acetylcholine receptor (α7nAChR). Beta-amyloid peptide (Aβ) binds to the α7nAChR, disrupting the receptor’s function and causing neurotoxicity. In vivo not only Aβ but also its modified forms can drive AD pathogenesis. One of these forms, iso-Aβ (containing an isomerized Asp7 residue), shows an increased neurotoxicity in vitro and stimulates amyloidogenesis in vivo. We suggested that such effects of iso-Aβ are α7nAChR-dependent. Here, using calcium imaging and electrophysiology, we found that iso-Aβ is a more potent inhibitor of the α7nAChR-mediated calcium current than unmodified Aβ. However, Asp7 isomerization eliminated the ability of Aβ to decrease the α7nAChR levels. These data indicate differences in the interaction of the peptides with the α7nAChR, which we demonstrated using computer modeling. Neither Aβ nor iso-Aβ competed with 125I-α-bungarotoxin for binding to the orthosteric site of the receptor, suggesting the allosteric binging mode of the peptides. Further we found that increased neurotoxicity of iso-Aβ was mediated by the α7nAChR. Thus, the isomerization of Asp7 enhances the inhibitory effect of Aβ on the functional activity of the α7nAChR, which may be an important factor in the disruption of the cholinergic system in AD.
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18
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Shin JH, Park SJ, Jo DS, Park NY, Kim JB, Bae JE, Jo YK, Hwang JJ, Lee JA, Jo DG, Kim JC, Jung YK, Koh JY, Cho DH. Down-regulated TMED10 in Alzheimer disease induces autophagy via ATG4B activation. Autophagy 2019; 15:1495-1505. [PMID: 30821607 DOI: 10.1080/15548627.2019.1586249] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Several studies have shown that dysfunction of macroautophagy/autophagy is associated with many human diseases, including neurodegenerative disease and cancer. To explore the molecular mechanisms of autophagy, we performed a cell-based functional screening with SH-SY5Y cells stably expressing GFP-LC3, using an siRNA library and identified TMED10 (transmembrane p24 trafficking protein 10), previously known as the γ-secretase-modulating protein, as a novel regulator of autophagy. Further investigations revealed that depletion of TMED10 induced the activation of autophagy. Interestingly, protein-protein interaction assays showed that TMED10 directly binds to ATG4B (autophagy related gene 4B cysteine peptidase), and the interaction is diminished under autophagy activation conditions such as rapamycin treatment and serum deprivation. In addition, inhibition of TMED10 significantly enhanced the proteolytic activity of ATG4B for LC3 cleavage. Importantly, the expression of TMED10 in AD (Alzheimer disease) patients was considerably decreased, and downregulation of TMED10 increased amyloid-β (Aβ) production. Treatment with Aβ increased ATG4B proteolytic activity as well as dissociation of TMED10 and ATG4B. Taken together, our results suggest that the AD-associated protein TMED10 negatively regulates autophagy by inhibiting ATG4B activity.Abbreviations: Aβ: amyloid-β; AD: Alzheimer disease; ATG: autophagy related; BECN1: beclin 1; BiFC: bimolecular fluorescence complementation; CD: cytosolic domain; GFP: green fluorescent protein; GLUC: Gaussia luciferase; IP: immunoprecipitation; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; LD: luminal domain; PD: Parkinson disease; ROS: reactive oxygen species; siRNA: small interfering RNA; SNP: single-nucleotide polymorphisms; TD: transmembrane domain; TMED10: transmembrane p24 trafficking protein 10; VC: C terminus of Venus fluorescent protein; VN: N terminus of Venus fluorescent protein.
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Affiliation(s)
- Ji Hyun Shin
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea.,b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - So Jung Park
- b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - Doo Sin Jo
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
| | - Na Yeon Park
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
| | - Joon Bum Kim
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
| | - Ji-Eun Bae
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea.,b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - Yoon Kyung Jo
- b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - Jung Jin Hwang
- c Asan Institute for Life Sciences, Asan Medical Center , Seoul , South Korea
| | - Jin-A Lee
- d College of Life Sciences and Nanotechnology, Hannam University , Daejeon , South Korea
| | - Dong-Gyu Jo
- e School of Pharmacy, Sungkyunkwan University , Suwon , South Korea
| | - Jin Cheon Kim
- f Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center , Seoul , South Korea
| | - Yong Keun Jung
- g School of Biological Sciences, Seoul National University , Seoul , South Korea
| | - Jae-Young Koh
- h Department of Neurology, University of Ulsan College of Medicine, Asan Medical Center , Seoul , South Korea
| | - Dong-Hyung Cho
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
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19
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Veloso AD, Ferraria AM, Botelho do Rego AM, Tavares PB, Valentão P, Pereira DD, Andrade PB, Fernandes AJ, Oliveira MC, Videira RA. Hydrophilic Carbon Nanomaterials: Characterisation by Physical, Chemical, and Biological Assays. ChemMedChem 2019; 14:699-711. [DOI: 10.1002/cmdc.201900003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/29/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Andreia D. Veloso
- CQ-VR and Chemistry DepartmentUniversity of Trás-os-Montes e Alto Douro 5000-801 Vila Real Portugal
| | - Ana M. Ferraria
- Centro de Química-Física Molecular and IN and IBBInstituto Superior TécnicoUniversidade de Lisboa 1049-001 Lisboa Portugal
| | - Ana M. Botelho do Rego
- Centro de Química-Física Molecular and IN and IBBInstituto Superior TécnicoUniversidade de Lisboa 1049-001 Lisboa Portugal
| | - Pedro B. Tavares
- CQ-VR and Chemistry DepartmentUniversity of Trás-os-Montes e Alto Douro 5000-801 Vila Real Portugal
| | - Patrícia Valentão
- REQUIMTE/LAQV, Laboratório de FarmacognosiaDepartamento de Química, Faculdade de FarmáciaUniversidade do Porto 4050-313 Porto Portugal
| | - David D. Pereira
- REQUIMTE/LAQV, Laboratório de FarmacognosiaDepartamento de Química, Faculdade de FarmáciaUniversidade do Porto 4050-313 Porto Portugal
| | - Paula B. Andrade
- REQUIMTE/LAQV, Laboratório de FarmacognosiaDepartamento de Química, Faculdade de FarmáciaUniversidade do Porto 4050-313 Porto Portugal
| | - António J. Fernandes
- I3N and Physics DepartmentUniversity of Aveiro Campus de Santiago 3810-193 Aveiro Portugal
| | - Maria C. Oliveira
- CQ-VR and Chemistry DepartmentUniversity of Trás-os-Montes e Alto Douro 5000-801 Vila Real Portugal
| | - Romeu A. Videira
- REQUIMTE/LAQV, Laboratório de FarmacognosiaDepartamento de Química, Faculdade de FarmáciaUniversidade do Porto 4050-313 Porto Portugal
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Liang X, Yao Y, Lin Y, Kong L, Xiao H, Shi Y, Yang J. Panaxadiol inhibits synaptic dysfunction in Alzheimer's disease and targets the Fyn protein in APP/PS1 mice and APP-SH-SY5Y cells. Life Sci 2019; 221:35-46. [PMID: 30735733 DOI: 10.1016/j.lfs.2019.02.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/02/2019] [Accepted: 02/04/2019] [Indexed: 12/12/2022]
Abstract
AIM Alzheimer's disease (AD), a neurodegenerative disease, is characterized by memory loss and synaptic damage. Up to now, there are limited drugs to cure or delay the state of this illness. Recently, the Fyn tyrosine kinase is implicated in AD pathology triggered by synaptic damage. Thus, Fyn inhibition may prevent or delay the AD progression. Therefore, in this paper, we investigated whether Panaxadiol could decrease synaptic damage in AD and the underlying mechanism. MAIN METHODS The ability of learning and memory of mice has detected by Morris Water Maze. The pathological changes detected by H&E staining and Nissl staining. The percentage of cell apoptosis and the calcium concentration were detected by Flow Cytometry in vitro. The amount of synaptic protein and related proteins in the Fyn/GluN2B/CaMKIIα signaling pathway were detected by Western Blot. KEY FINDINGS In the present article, Panaxadiol could significantly improve the ability of learning and memory of mice and reduce its synaptic dysfunction. Panaxadiol could down-regulate GluN2B's phosphorylation level by inhibition Fyn kinase activity, Subsequently, decrease Ca2+-mediated synaptic damage, reducing LDH leakage, inhibiting apoptosis in AD, resulting in facilitating the cells survival. For the underlying molecular mechanism, we used PP2 to block the Fyn/GluN2B/CaMKIIα signaling pathway. The results from WB showed that the expression of related proteins in the Fyn signaling pathway decreased with PP2 treated. SIGNIFICANCE Our results indicate that Panaxadiol could decrease synaptic damage, which will cause AD via inhibition of the Fyn/GluN2B/CaMKIIα signaling pathway. Thus, the Panaxadiol is a best promising candidate to test as a potential therapy for AD.
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Affiliation(s)
- Xicai Liang
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Yingjia Yao
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Ying Lin
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Liang Kong
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Honghe Xiao
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Yue Shi
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Jingxian Yang
- School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China.
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21
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Perillyl alcohol alleviates amyloid-β peptides-induced mitochondrial dysfunction and cytotoxicity in SH-SY5Y cells. Int J Biol Macromol 2018; 109:1029-1038. [DOI: 10.1016/j.ijbiomac.2017.11.082] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/21/2017] [Accepted: 11/13/2017] [Indexed: 12/20/2022]
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22
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Xanthoceraside modulates NR2B-containing NMDA receptors at synapses and rescues learning-memory deficits in APP/PS1 transgenic mice. Psychopharmacology (Berl) 2018; 235:337-349. [PMID: 29124300 DOI: 10.1007/s00213-017-4775-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/23/2017] [Indexed: 01/22/2023]
Abstract
RATIONALE Alzheimer's disease (AD) is characterized by memory loss and synaptic damage. Previous studies suggested that xanthoceraside decreases glutamate-induced PC12 cell death, ameliorates memory deficits, and increases the number of dendritic spines in AD mice. These results indicated that xanthoceraside might have activities that protect synaptic plasticity. Herein, we detected the effect of xanthoceraside on synaptic function. MATERIALS AND METHODS Three-month-old APP/PS1 transgenic mice were orally treated with xanthoceraside (0.02, 0.08, or 0.32 mg/kg) once daily for 4 months and then behavioral tests were performed. LTP and Fluo-4/AM were carried out in vivo and in vitro, respectively. CaMKII-GluR1 and NR2B-associated proteins on synapses were measured. RESULTS Xanthoceraside administration alleviated learning-memory deficits and increased the LTP in APP/PS1 transgenic mice. Meanwhile, xanthoceraside increased the expression of pT286-CaMKII in synaptic and extrasynaptic pools and CaMKII, pS831-GluR1, and GluR1 in synaptic pools. In addition, xanthoceraside increased the total pY1472-NR2B and NR2B expression and increased the levels of pY1472-NR2B in synaptic and extrasynaptic pools and NR2B in synaptic pools. However, NR2B was decreased in extrasynaptic pools, which might be associated with decreased expression of STEP61 and pY531-Fyn. In vitro studies showed that xanthoceraside inhibited intracellular calcium overload and increased the number of and extended the length of dendrites in primary hippocampal neurons compared with the Aβ25-35 group. CONCLUSIONS The mechanism of xanthoceraside on ameliorating learning-memory deficits might be related to decrease intracellular calcium overload, increase CaMKII-GluR1 proteins, and up-regulate trafficking of pY1472-NR2B at synapse, thereby improving LTP in APP/PS1 transgenic mice.
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Marinelli L, Fornasari E, Di Stefano A, Turkez H, Arslan ME, Eusepi P, Ciulla M, Cacciatore I. (R)-α-Lipoyl-Gly-l-Pro-l-Glu dimethyl ester as dual acting agent for the treatment of Alzheimer's disease. Neuropeptides 2017; 66:52-58. [PMID: 28993014 DOI: 10.1016/j.npep.2017.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 09/05/2017] [Accepted: 09/25/2017] [Indexed: 12/17/2022]
Abstract
In this study, effects of LA-GPE (R-α-Lipoyl-Gly-l-Pro-l-Glu dimethyl ester) and GPE (Gly-L-Pro-L-Glu) on the cytotoxic action of Aβ1-42 were tested with differentiated human neuroblastoma SH-SY5Y cells as cellular Alzheimer model via measurements of mitochondrial viability (MTT assay) and lactate dehydrogenase release (LDH assay). Effects of LA-GPE and GPE on acetylcholinesterase (AChE) activity, total antioxidant capacity (TAC) and total oxidative status (TOS) levels, and neural cell apoptosis and necrosis were also determined. In addition, biological safety of these novel formulations was evaluated in human blood cells using different cytotoxicity and genotoxicity assays. Our results indicated that both compounds could block Aβ1-42 induced cell death. LA-GPE reduced Aβ-induced AChE activity and oxidative stress, suggesting it as a multifunctional compound potentially valuable for the treatment of Alzheimer's disease (AD).
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Affiliation(s)
- Lisa Marinelli
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy
| | - Erika Fornasari
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy
| | - Antonio Di Stefano
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy
| | - Hasan Turkez
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy; Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University, 25240 Erzurum, Turkey
| | - Mehmet Enes Arslan
- Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University, 25240 Erzurum, Turkey
| | - Piera Eusepi
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy
| | - Michele Ciulla
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy
| | - Ivana Cacciatore
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, Chieti Scalo (CH), Italy.
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Lu JYD, Su P, Barber JEM, Nash JE, Le AD, Liu F, Wong AHC. The neuroprotective effect of nicotine in Parkinson's disease models is associated with inhibiting PARP-1 and caspase-3 cleavage. PeerJ 2017; 5:e3933. [PMID: 29062606 PMCID: PMC5651169 DOI: 10.7717/peerj.3933] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 09/26/2017] [Indexed: 12/20/2022] Open
Abstract
Clinical evidence points to neuroprotective effects of smoking in Parkinson’s disease (PD), but the molecular mechanisms remain unclear. We investigated the pharmacological pathways involved in these neuroprotective effects, which could provide novel ideas for developing targeted neuroprotective treatments for PD. We used the ETC complex I inhibitor methylpyridinium ion (MPP+) to induce cell death in SH-SY5Y cells as a cellular model for PD and found that nicotine inhibits cell death. Using choline as a nicotinic acetylcholine receptor (nAChR) agonist, we found that nAChR stimulation was sufficient to protect SH-SY5Y cells against cell death from MPP+. Blocking α7 nAChR with methyllycaconitine (MLA) prevented the protective effects of nicotine, demonstrating that these receptors are necessary for the neuroprotective effects of nicotine. The neuroprotective effect of nicotine involves other pathways relevant to PD. Cleaved Poly (ADP-ribose) polymerase-1 (PARP-1) and cleaved caspase-3 were decreased by nicotine in 6-hydroxydopamine (6-OHDA) lesioned mice and in MPP+-treated SH-SY5Y cells. In conclusion, our data indicate that nicotine likely exerts neuroprotective effects in PD through the α7 nAChR and downstream pathways including PARP-1 and caspase-3. This knowledge could be pursued in future research to develop neuroprotective treatments for PD.
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Affiliation(s)
- Justin Y D Lu
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Ping Su
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - James E M Barber
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto, Scarborough, Toronto, Ontario, Canada
| | - Joanne E Nash
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto, Scarborough, Toronto, Ontario, Canada
| | - Anh D Le
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Fang Liu
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Albert H C Wong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
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Paul A, Kumar S, Kalita S, Ghosh AK, Mondal AC, Mandal B. A Peptide Based Pro-drug Disrupts Alzheimer’s Amyloid into Non-toxic Species and Reduces Aβ Induced Toxicity In Vitro. Int J Pept Res Ther 2017. [DOI: 10.1007/s10989-017-9602-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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26
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Song N, Zhang L, Chen W, Zhu H, Deng W, Han Y, Guo J, Qin C. Cyanidin 3- O -β-glucopyranoside activates peroxisome proliferator-activated receptor-γ and alleviates cognitive impairment in the APP swe /PS1 ΔE9 mouse model. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1786-800. [DOI: 10.1016/j.bbadis.2016.05.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/04/2016] [Accepted: 05/26/2016] [Indexed: 12/11/2022]
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27
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Xu W, Yang L, Li J. Protection against β-amyloid-induced neurotoxicity by naturally occurring Z-ligustilide through the concurrent regulation of p38 and PI3-K/Akt pathways. Neurochem Int 2016; 100:44-51. [PMID: 27580711 DOI: 10.1016/j.neuint.2016.08.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 08/12/2016] [Accepted: 08/26/2016] [Indexed: 01/06/2023]
Abstract
Alzheimer's disease (AD) is primarily characterized by the progressive loss of functional neurons in the brain. Therefore, compounds with neuroprotective property may have therapeutic value in treating AD. Z-ligustilide (Z-LIG) is an essential oil originally isolated from umbelliferous plants. In the current study, the neuroprotective effects and underlying mechanisms of Z-LIG against fibrillar aggregates of Aβ25-35 and Aβ1-42-induced neurotoxicity were investigated in both SH-SY5Y cells and differentiated PC12 cells. Z-LIG at 1-30 μM provided an effective neuroprotection, as evidenced by the increase in cell viability, as well as the decrease in LDH release and intracellular accumulation of reactive oxygen species. Additionally, Z-LIG markedly blocked Aβ fibrils-induced condensed nuclei and sub-G1 accumulation suggestive of apoptosis. Furthermore, Z-LIG substantially reversed the activation of phosphorylated p38 and the inhibition of phosphorylated Akt caused by Aβ25-35. LY294002, the specific inhibitor of PI3-K, significantly abrogated the protein expression of up-regulated phosphorylated Akt offered by Z-LIG. Most importantly, siRNA-mediated knockdown of PI3-K and p38 significantly abolished the neuroprotective effects of Z-LIG. The results taken together indicate that Z-LIG protects against Aβ fibrils-induced neurotoxicity possibly through the inhibition of p38 and activation of PI3-K/Akt signaling pathways concurrently. Z-LIG might be a potential candidate for further preclinical study aimed at the prevention and treatment of AD.
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Affiliation(s)
- Wei Xu
- Department of Neurology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China.
| | - Li Yang
- Department of Neurology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Ji Li
- Department of Neurology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
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28
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Liang Z, Zhang B, Su WW, Williams PG, Li QX. C-Glycosylflavones Alleviate Tau Phosphorylation and Amyloid Neurotoxicity through GSK3β Inhibition. ACS Chem Neurosci 2016; 7:912-23. [PMID: 27213824 DOI: 10.1021/acschemneuro.6b00059] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Alzheimer's disease (AD) is the most common brain disorder worldwide. Aberrant tau hyperphosphorylation and accumulation play critical roles in the formation of neurofibrillary tangles highly associated with neuronal dysfunction and cognitive impairment in AD pathogenesis. Glycogen synthase kinase-3β (GSK3β) is a key kinase responsible for tau hyperphosphorylation. Selective inhibition of GSK3β is a promising strategy in AD therapy. Corn silks (CS, Zea mays L.) have been traditionally used as a medicinal herb and recently noted for their potentially cognitive benefits. However, the neuroprotective components of CS and their molecular mechanism have received little attention to date. As part of our effort screening phytochemicals against a broad panel of kinases targeting AD tauopathy, we found inhibition of GSK3β by CS extracts. Subsequent bioassay-guided fractionation led to the isolation and identification of two 6-C-glycosylflavones, isoorientin (1) and 3'-methoxymaysin (2), with selective inhibition against GSK3β in vitro. Enzyme kinetics and molecular docking studies demonstrated that 1 specifically inhibited GSK3β via an ATP noncompetitive mechanism, acting as a substrate competitive inhibitor of GSK3β. Further in vitro cellular studies demonstrated that 1 effectively attenuated tau phosphorylation mediated by GSK3β and was neuroprotective against β-amyloid-induced tau hyperphosphorylation and neurotoxicity in SH-SY5Y cells. The C-glycosylflavones represent new lead candidates with a novel mechanism of action for the development of AD phytopharmaceuticals.
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Affiliation(s)
- Zhibin Liang
- Department of Molecular Biosciences and Bioengineering, and ‡Department of
Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Bei Zhang
- Department of Molecular Biosciences and Bioengineering, and ‡Department of
Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Wei Wen Su
- Department of Molecular Biosciences and Bioengineering, and ‡Department of
Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Philip G. Williams
- Department of Molecular Biosciences and Bioengineering, and ‡Department of
Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Qing X. Li
- Department of Molecular Biosciences and Bioengineering, and ‡Department of
Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
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