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Quan Q, Ma X, Li M, Li X, Yuan H. Ginsenoside Rg1 promotes β‑amyloid peptide degradation through inhibition of the ERK/PPARγ phosphorylation pathway in an Alzheimer's disease neuronal model. Exp Ther Med 2024; 27:31. [PMID: 38125359 PMCID: PMC10731411 DOI: 10.3892/etm.2023.12319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 10/27/2023] [Indexed: 12/23/2023] Open
Abstract
β-Amyloid peptide (Aβ) deposition in the brain is an important pathological change in Alzheimer's disease (AD). Insulin-degrading enzyme (IDE), which is regulated transcriptionally by peroxisome proliferator-activated receptor γ (PPARγ), is able to proteolyze Aβ. One of the members of the MAPK family, ERK, is able to mediate the phosphorylation of PPARγ at Ser112, thereby inhibiting its transcriptional activity. Ginsenoside Rg1 is one of the active ingredients in the natural medicine ginseng and has inhibitory effects on Aβ production. The present study was designed to investigate whether ginsenoside Rg1 is able to affect the regulation of PPARγ based on the expression of its target gene, IDE, and whether it is able to promote Aβ degradation via inhibition of the ERK/PPARγ phosphorylation pathway. In the present study, primary cultured rat hippocampal neurons were treated with Aβ1-42, ginsenoside Rg1 and the ERK inhibitor PD98059, and subsequently TUNEL staining was used to detect the level of neuronal apoptosis. ELISA was subsequently employed to detect the intra- and extracellular Aβ1-42 levels, immunofluorescence staining and western blotting were used to detect the translocation of ERK from the cytoplasm to the nucleus, immunofluorescence double staining was used to detect the co-expression of ERK and PPARγ, and finally, western blotting was used to detect the phosphorylation of PPARγ at Ser112 and IDE expression. The results demonstrated that ginsenoside Rg1 or PD98059 were able to inhibit primary cultured hippocampal neuron apoptosis induced by Aβ1-42 treatment, reduce the levels of intra- and extraneuronal Aβ1-42 and inhibit the translocation of ERK from the cytoplasm to the nucleus. Furthermore, administration of ginsenoside Rg1 or PD98059 resulted in attenuated co-expression of ERK and PPARγ, inhibition of phosphorylation of PPARγ at Ser112 mediated by ERK and an increase in IDE expression. In addition, the effects when PD98059 to inhibit ERK followed by treatment with ginsenoside Rg1 were found to be more pronounced than those when using PD98059 alone. In conclusion, ginsenoside Rg1 was demonstrated to exert neuroprotective effects on AD via inhibition of the ERK/PPARγ phosphorylation pathway, which led to an increase in IDE expression, the promotion of Aβ degradation and the decrease of neuronal apoptosis. These results could provide a theoretical basis for the clinical application of ginsenoside Rg1 in AD.
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Affiliation(s)
- Qiankun Quan
- Department of Geriatrics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Xinxin Ma
- Department of Psychology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Ming Li
- Department of Geriatrics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Xi Li
- Department of Geriatrics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Haifeng Yuan
- Department of Rehabilitation, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
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Grünblatt E, Homolak J, Babic Perhoc A, Davor V, Knezovic A, Osmanovic Barilar J, Riederer P, Walitza S, Tackenberg C, Salkovic-Petrisic M. From attention-deficit hyperactivity disorder to sporadic Alzheimer's disease-Wnt/mTOR pathways hypothesis. Front Neurosci 2023; 17:1104985. [PMID: 36875654 PMCID: PMC9978448 DOI: 10.3389/fnins.2023.1104985] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder with the majority of patients classified as sporadic AD (sAD), in which etiopathogenesis remains unresolved. Though sAD is argued to be a polygenic disorder, apolipoprotein E (APOE) ε4, was found three decades ago to pose the strongest genetic risk for sAD. Currently, the only clinically approved disease-modifying drugs for AD are aducanumab (Aduhelm) and lecanemab (Leqembi). All other AD treatment options are purely symptomatic with modest benefits. Similarly, attention-deficit hyperactivity disorder (ADHD), is one of the most common neurodevelopmental mental disorders in children and adolescents, acknowledged to persist in adulthood in over 60% of the patients. Moreover, for ADHD whose etiopathogenesis is not completely understood, a large proportion of patients respond well to treatment (first-line psychostimulants, e.g., methylphenidate/MPH), however, no disease-modifying therapy exists. Interestingly, cognitive impairments, executive, and memory deficits seem to be common in ADHD, but also in early stages of mild cognitive impairment (MCI), and dementia, including sAD. Therefore, one of many hypotheses is that ADHD and sAD might have similar origins or that they intercalate with one another, as shown recently that ADHD may be considered a risk factor for sAD. Intriguingly, several overlaps have been shown between the two disorders, e.g., inflammatory activation, oxidative stress, glucose and insulin pathways, wingless-INT/mammalian target of rapamycin (Wnt/mTOR) signaling, and altered lipid metabolism. Indeed, Wnt/mTOR activities were found to be modified by MPH in several ADHD studies. Wnt/mTOR was also found to play a role in sAD and in animal models of the disorder. Moreover, MPH treatment in the MCI phase was shown to be successful for apathy including some improvement in cognition, according to a recent meta-analysis. In several AD animal models, ADHD-like behavioral phenotypes have been observed indicating a possible interconnection between ADHD and AD. In this concept paper, we will discuss the various evidence in human and animal models supporting the hypothesis in which ADHD might increase the risk for sAD, with common involvement of the Wnt/mTOR-pathway leading to lifespan alteration at the neuronal levels.
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Affiliation(s)
- Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich (PUK), University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and the Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Jan Homolak
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Virag Davor
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Jelena Osmanovic Barilar
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Peter Riederer
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital Würzburg, Würzburg, Germany.,Department and Research Unit of Psychiatry, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich (PUK), University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and the Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Christian Tackenberg
- Neuroscience Center Zurich, University of Zurich and the Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.,Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren, Switzerland
| | - Melita Salkovic-Petrisic
- Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
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Engin AB, Engin A. Risk of Alzheimer's disease and environmental bisphenol A exposure. CURRENT OPINION IN TOXICOLOGY 2021. [DOI: 10.1016/j.cotox.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ding Y, Liu H, Cen M, Tao Y, Lai C, Tang Z. Rapamycin Ameliorates Cognitive Impairments and Alzheimer's Disease-Like Pathology with Restoring Mitochondrial Abnormality in the Hippocampus of Streptozotocin-Induced Diabetic Mice. Neurochem Res 2021; 46:265-275. [PMID: 33140268 DOI: 10.1007/s11064-020-03160-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 10/22/2020] [Accepted: 10/26/2020] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) and diabetes mellitus (DM) share common pathophysiological findings, in particular, the mammalian target of rapamycin (mTOR) has been strongly implied to link to AD, while it also plays a key role in the insulin signaling pathway. However, the mechanism of how DM and AD is coupled remains elusive. In the present study, we found that streptozotocin (STZ)-induced DM mice significantly increased the levels P-mTOR Ser2448, P-p70S6K Thr389, P-tau Ser356 and Aβ levels (Aβ oligomer/monomer), as well as the levels of Drp1 and p-Drp1 S616 (mitochondrial fission proteins) are increased, whereas no change was found in the expression of Opa1, Mfn1 and Mfn2 (mitochondrial fusion proteins) compared with control mice. Moreover, the expression of 4-HNE and 8-OHdG showed an aberrant increase in the hippocampus of STZ-induced DM mice that is associated with a decreased capacity of spatial memory and a loss of synapses. Rapamycin, an inhibitor of mTOR, rescued the STZ-induced increases in mTOR/p70S6K activities, tau phosphorylation and Aβ levels, as well as mitochondria abnormality and cognitive impairment in mice. These findings imply that rapamycin prevents cognitive impairment and protects hippocampus neurons from AD-like pathology and mitochondrial abnormality, and also that rapamycin treatment could normalize these STZ-induced alterations by decreasing hippocampus mTOR/p70S6K hyperactivity.
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Affiliation(s)
- Yuanting Ding
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Heng Liu
- Department of Anesthesiology, Tongren Municipal People's Hospital, Tongren, 554300, Guizhou, China
| | - Mofei Cen
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Yuxiang Tao
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Chencen Lai
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China
| | - Zhi Tang
- Department of Clinical Research Center, The First Affliated Hospital of Guizhou University of Traditional Chinese Medicine, Baoshan Road No.71, Guiyang, 550001, Guizhou, China.
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Engin AB, Engin A. Alzheimer's Disease and Protein Kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:285-321. [PMID: 33539020 DOI: 10.1007/978-3-030-49844-3_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and accounts for more than 60-80% of all cases of dementia. Loss of pyramidal neurons, extracellular amyloid beta (Abeta) accumulated senile plaques, and neurofibrillary tangles that contain hyperphosphorylated tau constitute the main pathological alterations in AD.Synaptic dysfunction and extrasynaptic N-methyl-D-aspartate receptor (NMDAR) hyperactivation contributes to excitotoxicity in patients with AD. Amyloid precursor protein (APP) and Abeta promoted neurodegeneration develop through the activation of protein kinase signaling cascade in AD. Furthermore, ultimate neuronal death in AD is under control of protein kinases-related signaling pathways. In this chapter, critical check-points within the cross-talk between neuron and protein kinases have been defined regarding the initiation and progression of AD. In this context, amyloid cascade hypothesis, neuroinflammation, oxidative stress, granulovacuolar degeneration, loss of Wnt signaling, Abeta-related synaptic alterations, prolonged calcium ions overload and NMDAR-related synaptotoxicity, damage signals hypothesis and type-3 diabetes are discussed briefly.In addition to clinical perspective of AD pathology, recommendations that might be effective in the treatment of AD patients have been reviewed.
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Affiliation(s)
- Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
| | - Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
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Dysfunction of the neurovascular unit in diabetes-related neurodegeneration. Biomed Pharmacother 2020; 131:110656. [PMID: 32841897 DOI: 10.1016/j.biopha.2020.110656] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/10/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022] Open
Abstract
In current aging societies, diabetes mellitus and neurodegenerative diseases represented by Alzheimer's disease are highly prevalent among adults, especially the elderly all over the world. It is worth noting that a substantial body of evidence suggests diabetes contributes to accelerated neurodegenerative processes and the decline of cognition. Over the last few years, some studies have indicated neurovascular uncoupling and disrupted functional connectivity in the early stages of many neurodegenerative diseases, and the concept of the neurovascular unit (NVU) has been highlighted to understand the initiation and progression of neurodegenerative diseases recently. Considering that some components of the NVU are also demonstrated to have abnormal morphology and function under the condition of diabetes, we propose the hypothesis that diabetes may promote the onset and development of neurodegenerative diseases by impairing the integrity of the NVU, named Diabetes-NVU-Neurodegeneration Hypothesis. The existing body of literature supporting the hypothesis and elucidating the underlying mechanisms will be summarized in this review.
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Youssef DA, El-Fayoumi HM, Mahmoud MF. Beta-caryophyllene alleviates diet-induced neurobehavioral changes in rats: The role of CB2 and PPAR-γ receptors. Biomed Pharmacother 2019; 110:145-154. [DOI: 10.1016/j.biopha.2018.11.039] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 10/30/2018] [Accepted: 11/10/2018] [Indexed: 11/16/2022] Open
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Javanshiri K, Waldö ML, Friberg N, Sjövall F, Wickerström K, Haglund M, Englund E. Atherosclerosis, Hypertension, and Diabetes in Alzheimer’s Disease, Vascular Dementia, and Mixed Dementia: Prevalence and Presentation. J Alzheimers Dis 2018; 65:1247-1258. [DOI: 10.3233/jad-180644] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Keivan Javanshiri
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Sweden
| | - Maria Landqvist Waldö
- Department of Clinical Sciences Lund, Division of Clinical Sciences Helsingborg, Lund University, Sweden
| | - Niklas Friberg
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Sweden
| | - Fredrik Sjövall
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Sweden
| | - Karin Wickerström
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Sweden
| | - Mattias Haglund
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Sweden
| | - Elisabet Englund
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Sweden
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The diabetic brain and cognition. J Neural Transm (Vienna) 2017; 124:1431-1454. [PMID: 28766040 DOI: 10.1007/s00702-017-1763-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 07/13/2017] [Indexed: 12/20/2022]
Abstract
The prevalence of both Alzheimer's disease (AD) and vascular dementia (VaD) is increasing with the aging of the population. Studies from the last several years have shown that people with diabetes have an increased risk for dementia and cognitive impairment. Therefore, the authors of this consensus review tried to elaborate on the role of diabetes, especially diabetes type 2 (T2DM) in both AD and VaD. Based on the clinical and experimental work of scientists from 18 countries participating in the International Congress on Vascular Disorders and on literature search using PUBMED, it can be concluded that T2DM is a risk factor for both, AD and VaD, based on a pathology of glucose utilization. This pathology is the consequence of a disturbance of insulin-related mechanisms leading to brain insulin resistance. Although the underlying pathological mechanisms for AD and VaD are different in many aspects, the contribution of T2DM and insulin resistant brain state (IRBS) to cerebrovascular disturbances in both disorders cannot be neglected. Therefore, early diagnosis of metabolic parameters including those relevant for T2DM is required. Moreover, it is possible that therapeutic options utilized today for diabetes treatment may also have an effect on the risk for dementia. T2DM/IRBS contribute to pathological processes in AD and VaD.
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Grünblatt E, Bartl J, Iuhos DI, Knezovic A, Trkulja V, Riederer P, Walitza S, Salkovic-Petrisic M. Characterization of cognitive deficits in spontaneously hypertensive rats, accompanied by brain insulin receptor dysfunction. J Mol Psychiatry 2015; 3:6. [PMID: 26110057 PMCID: PMC4479234 DOI: 10.1186/s40303-015-0012-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/29/2015] [Indexed: 01/05/2023] Open
Abstract
Background The spontaneously hypertensive rat (SHR) has been used to model changes in the central nervous system associated with cognitive-related disorders. Recent human and animal studies indicate a possible relationship between cognitive deficits, insulin resistance and hypertension. We aimed to investigate whether cognitively impaired SHRs develop central and/or peripheral insulin resistance and how their cognitive performance is influenced by the animal’s sex and age as well as strains used for comparison (Wistar and Wistar-Kyoto/WKY). Methods Three and seven-month-old SHR, Wistar, and WKY rats were studied for their cognitive performance using Morris Water Maze (MWM) and Passive Avoidance tests (PAT). Plasma glucose and insulin were obtained after oral glucose tolerance tests. Cerebral cortex, hippocampus, and striatum status of insulin-receptor (IR) β-subunit and glycogen synthase kinase-3β (GSK3β) and their phosphorylated forms were obtained via ELISA. Results SHRs performed poorly in MWM and PAT in comparison to both control strains but more pronouncedly compared to WKY. Females performed poorer than males and 7-month-old SHRs had poorer MWM performance than 3-month-old ones. Although plasma glucose levels remained unchanged, plasma insulin levels were significantly increased in the glucose tolerance test in 7-month-old SHRs. SHRs demonstrated reduced expression and increased activity of IRβ-subunit in cerebral cortex, hippocampus, and striatum with different regional changes in phospho/total GSK3β ratio, as compared to WKYs. Conclusion Results indicate that cognitive deficits in SHRs are accompanied by both central and peripheral insulin dysfunction, thus allowing for the speculation that SHRs might additionally be considered as a model of insulin resistance-induced type of dementia. Electronic supplementary material The online version of this article (doi:10.1186/s40303-015-0012-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Edna Grünblatt
- University Clinics of Child and Adolescent Psychiatry, University of Zurich, Neumuensterallee 9, 8032 Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland ; University Hospital, Clinic and Policlinic for Psychiatry, Psychosomatic and Psychotherapy, University of Würzburg, Füchsleinstr. 15, D-97080 Würzburg, Germany ; University Clinics of Child and Adolescent Psychiatry, University of Zurich, Wagistrasse 12, CH-8952 Schlieren, Switzerland
| | - Jasmin Bartl
- University Clinics of Child and Adolescent Psychiatry, University of Zurich, Neumuensterallee 9, 8032 Zurich, Switzerland
| | - Diana-Iulia Iuhos
- University Hospital, Clinic and Policlinic for Psychiatry, Psychosomatic and Psychotherapy, University of Würzburg, Füchsleinstr. 15, D-97080 Würzburg, Germany
| | - Ana Knezovic
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 11, 10 000 Zagreb, Croatia
| | - Vladimir Trkulja
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 11, 10 000 Zagreb, Croatia
| | - Peter Riederer
- University Hospital, Clinic and Policlinic for Psychiatry, Psychosomatic and Psychotherapy, University of Würzburg, Füchsleinstr. 15, D-97080 Würzburg, Germany
| | - Susanne Walitza
- University Clinics of Child and Adolescent Psychiatry, University of Zurich, Neumuensterallee 9, 8032 Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Melita Salkovic-Petrisic
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 11, 10 000 Zagreb, Croatia
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Strobel S, Grünblatt E, Riederer P, Heinsen H, Arzberger T, Al-Sarraj S, Troakes C, Ferrer I, Monoranu CM. Changes in the expression of genes related to neuroinflammation over the course of sporadic Alzheimer's disease progression: CX3CL1, TREM2, and PPARγ. J Neural Transm (Vienna) 2015; 122:1069-76. [PMID: 25596843 DOI: 10.1007/s00702-015-1369-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/12/2015] [Indexed: 12/28/2022]
Abstract
The role of neuroinflammation in the pathogenesis of neurodegenerative diseases has become more evident in recent years. Research on the etiology and pathogenesis of sporadic Alzheimer's disease (AD) has focused on the role of chemokines such as CX3CL1, on the triggering receptors expressed by myeloid cells (TREMs), especially TREM2, and on the transcription factor/nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARγ). Here we analyzed the expression levels of CX3CL1, TREM2, and PPARγ in tissue homogenates from human brain regions that have different degrees of vulnerability to neuropathological AD-related changes to obtain insights into the pathogenesis and progression of AD. We found that CX3CL1 and TREM2, two genes related to neuroinflammation, are more highly expressed in brain regions with pronounced vulnerability to AD-related changes, such as the hippocampus, and that the expression levels reflect the course of the disease, whereas regions with low vulnerability to AD, seemed generally less affected by neuroinflammation. Furthermore, our results support previous findings of significantly higher CX3CL1 plasma levels in patients with mild to moderate AD than in patients with severe AD. Thus, CX3CL1 should be considered as promising additional marker for the early diagnosis of AD and underlines once more, the involvement of the neuroinflammation in the pathogenesis of this neurodegenerative disease.
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Affiliation(s)
- S Strobel
- Department of Neuropathology, Institute of Pathology, University of Wuerzburg, Josef-Schneider-Str. 2, 97080, Wuerzburg, Germany
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Cai Z, Yan Y, Wang Y. Minocycline alleviates beta-amyloid protein and tau pathology via restraining neuroinflammation induced by diabetic metabolic disorder. Clin Interv Aging 2013; 8:1089-95. [PMID: 23983461 PMCID: PMC3749817 DOI: 10.2147/cia.s46536] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Compelling evidence has shown that diabetic metabolic disorder plays a critical role in the pathogenesis of Alzheimer's disease, including increased expression of β-amyloid protein (Aβ) and tau protein. Evidence has supported that minocycline, a tetracycline derivative, protects against neuroinflammation induced by neurodegenerative disorders or cerebral ischemia. This study has evaluated minocycline influence on expression of Aβ protein, tau phosphorylation, and inflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the brain of diabetic rats to clarify neuroprotection by minocycline under diabetic metabolic disorder. METHOD An animal model of diabetes was established by high fat diet and intraperitoneal injection of streptozocin. In this study, we investigated the effect of minocycline on expression of Aβ protein, tau phosphorylation, and inflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the hippocampus of diabetic rats via immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay. RESULTS These results showed that minocycline decreased expression of Aβ protein and lowered the phosphorylation of tau protein, and retarded the proinflammatory cytokines, but not amyloid precursor protein. CONCLUSION On the basis of the finding that minocycline had no influence on amyloid precursor protein and beta-site amyloid precursor protein cleaving enzyme 1 which determines the speed of Aβ generation, the decreases in Aβ production and tau hyperphosphorylation by minocycline are through inhibiting neuroinflammation, which contributes to Aβ production and tau hyperphosphorylation. Minocycline may also lower the self-perpetuating cycle between neuroinflammation and the pathogenesis of tau and Aβ to act as a neuroprotector. Therefore, the ability of minocycline to modulate inflammatory reactions may be of great importance in the selection of neuroprotective agents, especially in chronic conditions like diabetes and Alzheimer's disease.
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Affiliation(s)
- Zhiyou Cai
- Department of Neurology, the Lu'an Affiliated Hospital of Anhui Medical University, Lu'an People's Hospital, Lu'an, Anhui Province, People's Republic of China.
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Fiolaki A, Tsamis KI, Milionis HJ, Kyritsis AP, Kosmidou M, Giannopoulos S. Atherosclerosis, biomarkers of atherosclerosis and Alzheimer's disease. Int J Neurosci 2013; 124:1-11. [DOI: 10.3109/00207454.2013.821988] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Karczewski P, Pohlmann A, Wagenhaus B, Wisbrun N, Hempel P, Lemke B, Kunze R, Niendorf T, Bimmler M. Antibodies to the α1-adrenergic receptor cause vascular impairments in rat brain as demonstrated by magnetic resonance angiography. PLoS One 2012; 7:e41602. [PMID: 22860001 PMCID: PMC3408502 DOI: 10.1371/journal.pone.0041602] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 06/24/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Circulating agonistic autoantibodies acting at G protein-coupled receptors have been associated with numerous sever pathologies in humans. Antibodies directed predominantly against the α(1)-adrenergig receptor were detected in patients suffering from widespread diseases such as hypertension and type 2 diabetes. Their deleterious action has been demonstrated for peripheral organs. We postulate that antibodies to the α(1)-adrenergig receptor are relevant pathomolecules in diseases of the central nervous system associated with vascular impairments. METHODOLOGY/PRINCIPAL FINDINGS Using a rat model we studied the long-term action of antibodies against the α(1)-adrenergig receptor either induced by immunization with a receptor peptide or applied by intravenous injection. The vasculature in the rat brains was investigated by time-of-flight magnetic resonance angiography using a 9.4 Tesla small animal MR imaging system. Visual examination of maximum-intensity-projections (MIPs) of brain angiographs revealed the development of vascular defects in antibody- exposed animals between three and eight months of treatment. Relative vascular areas were derived from representative MIP image sections by grayscale analysis and used to form an index of vascular circulation. Animals exposed to the action of α(1)-adrenergig receptor antibodies showed significantly reduced vascular areas (p<0.05). Calculated index values indicated attenuated blood flow in both antibody-treated cohorts compared to their respective controls reaching with (relative units ± standard error, n = 10) 0.839 ± 0.026 versus 0.919 ± 0.026 statistical significance (p<0.05) for peptide-immunized rats. CONCLUSION/SIGNIFICANCE We present evidence that antibodies to the α(1)-adrenergig receptor cause cerebrovascular impairments in the rat. Our findings suggest the pathological significance of these antibodies in pathologies of the human central nervous system linked to impairments of brain vasculature such as stroke and dementia.
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Different effects of soluble and aggregated amyloid β42 on gene/protein expression and enzyme activity involved in insulin and APP pathways. J Neural Transm (Vienna) 2012; 120:113-20. [PMID: 22782687 DOI: 10.1007/s00702-012-0852-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
Abstract
Although Alzheimer's dementia (AD) is not characterised any longer simply as the accumulation and deposition of amyloid beta (Aβ) peptides and hyperphosphorylation of tau proteins within the brain, excessive Aβ(42) deposition is still considered to play a major role in this illness. Aβ are able to adopt many differently aggregate forms, including amyloid fibrils as well as nonfibrillar structures (soluble Aβ(42) oligomers). It is not well-established that which Aβ(42) state is most responsible for AD or why. We wanted to verify which effects Aβ(42) oligomers and aggregated peptides have on gene expression, protein level and enzyme activity of insulin and amyloid precursor protein (APP) pathways in vitro. Human neuroblastoma cells (SH-SY5Y) were treated with varying concentrations of soluble and aggregated Aβ(42). Treatment effects on β-secretase (BACE), glycogen synthase kinase 3α (GSK3α), glycogen synthase kinase 3β (GSK3β), phosphatidylinositol-3 kinase (PI-3K), insulin-degrading enzyme (IDE), insulin-receptor substrate 1 (IRS1), insulin receptor (INSR) and monoamine oxidase B (MAO-B) were investigated via quantitative-PCR, western blot, ELISA and enzyme activity assay. We could find different effects of soluble and aggregated peptides especially on gene/protein expression of GSK3β and INSR and on GSK3β and MAO-B activity. Soluble peptides showed significant effects leading to increased gene expression and protein amount of GSK3β and to decreased level of gene and protein expression of INSR. MAO-B activity was enhanced after treatment with aggregated peptides and strongly inhibited after soluble Aβ(42) treatment. Our data might provide insights into selective effects of specific forms of Aβ(42) aggregates in AD.
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