1
|
Gharai PK, Khan J, Mallesh R, Garg S, Saha A, Ghosh S, Ghosh S. Vanillin Benzothiazole Derivative Reduces Cellular Reactive Oxygen Species and Detects Amyloid Fibrillar Aggregates in Alzheimer's Disease Brain. ACS Chem Neurosci 2023; 14:773-786. [PMID: 36728363 DOI: 10.1021/acschemneuro.2c00771] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The misfolding of amyloid beta (Aβ) peptides into Aβ fibrillary aggregates is a major hallmark of Alzheimer's disease (AD), which responsible for the excess production of hydrogen peroxide (H2O2), a prominent reactive oxygen species (ROS) from the molecular oxygen (O2) by the reduction of the Aβ-Cu(I) complex. The excessive production of H2O2 causes oxidative stress and inflammation in the AD brain. Here, we have designed and developed a dual functionalized molecule VBD by using π-conjugation (C═C) in the backbone structure. In the presence of H2O2, the VBD can turn into fluorescent probe VBD-1 by cleaving of the selective boronate ester group. The fluorescent probe VBD-1 can undergo intramolecular charge transfer transition (ICT) by a π-conjugative system, and as a result, its emission increases from the yellow (532 nm) to red (590 nm) region. The fluorescence intensity of VBD-1 increases by 3.5-fold upon binding with Aβ fibrillary aggregates with a high affinity (Kd = 143 ± 12 nM). Finally, the VBD reduces the cellular toxic H2O2 as proven by the CCA assay and DCFDA assay and the binding affinity of VBD-1 was confirmed by using in vitro histological staining in 8- and 18-month-old triple transgenic AD (3xTg-AD) mice brain slices.
Collapse
Affiliation(s)
- Prabir Kumar Gharai
- Organic and Medicinal Chemistry and Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, WB, India.,Department of Bioscience & Bioengineering, Indian Institute of Technology, Jodhpur, NH 65, Surpura Bypass Road, Karwar, Rajasthan 342037, India
| | - Juhee Khan
- Organic and Medicinal Chemistry and Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, WB, India.,Department of Bioscience & Bioengineering, Indian Institute of Technology, Jodhpur, NH 65, Surpura Bypass Road, Karwar, Rajasthan 342037, India
| | - Rathnam Mallesh
- Organic and Medicinal Chemistry and Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, WB, India.,Department of Bioscience & Bioengineering, Indian Institute of Technology, Jodhpur, NH 65, Surpura Bypass Road, Karwar, Rajasthan 342037, India.,National Institute of Pharmaceutical Education and Research, Kolkata, Chunilal Bhawan 168, Maniktala Main Road, Kolkata 700054, India
| | - Shubham Garg
- Department of Bioscience & Bioengineering, Indian Institute of Technology, Jodhpur, NH 65, Surpura Bypass Road, Karwar, Rajasthan 342037, India
| | - Abhijit Saha
- Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, India
| | - Subhajit Ghosh
- Organic and Medicinal Chemistry and Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, WB, India
| | - Surajit Ghosh
- Organic and Medicinal Chemistry and Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, WB, India.,Department of Bioscience & Bioengineering, Indian Institute of Technology, Jodhpur, NH 65, Surpura Bypass Road, Karwar, Rajasthan 342037, India.,National Institute of Pharmaceutical Education and Research, Kolkata, Chunilal Bhawan 168, Maniktala Main Road, Kolkata 700054, India
| |
Collapse
|
2
|
Wu ZG, Huang YJ, Wang TY, Deng CY, Xu ZR, Tang CZ. Effect of acupuncture on neuroinflammation in animal models of Alzheimer's disease: A preclinical systematic review and meta-analysis. Front Aging Neurosci 2023; 15:1110087. [PMID: 36936500 PMCID: PMC10014858 DOI: 10.3389/fnagi.2023.1110087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Background Despite neuroinflammation being an important component of the pathology of Alzheimer's disease (AD), effective therapies to alleviate neuroinflammation are still lacking. Many animal experiments in AD have found that acupuncture may ameliorate cognition by decreasing neuroinflammation and modulating cytokines, but its effects have not been systematically examined. We aimed to assess its efficacy on neuroinflammation in AD and to investigate the potential mechanisms. Materials and methods The following databases were searched from inception until 24 August 2022: Web of Science, EMBASE, PubMed, the Cochrane Library, and China National Knowledge Infrastructure. Animal studies that reported the efficacy of acupuncture on neuroinflammation in AD were included. The SYRCLE Robt was utilized to evaluate methodological quality. Stata 17 was utilized to conduct a meta-analysis of cytokine levels and the results of the Morris water maze. Results 23 studies were included, with a total of 417 rats/mice. The overall quality of all included reports was medium. The results indicated that acupuncture significantly reduced the expressions of pro-inflammatory cytokines which included IL-1β [SMD = -3.50, 95% CI (-4.31, -2.69); I 2 = 78.6%] (P < 0.05), TNF-α [SMD = -3.05, 95% CI (-3.86, -2.24); I 2 = 69.6%] (P < 0.05), IL-6 [SMD = -3.22, 95% CI (-4.62, -1.81); I 2 = 77.6%] and enhanced the expressions of anti-inflammatory cytokines including IL-4 [SMD = 2.77, 95% CI (1.95, 3.59); I 2 = 33.9%] (P < 0.05), IL-10 [SMD = 1.84, 95% CI (1.20, 2.49); I 2 = 41.0%] (P < 0.05) in an animal model of AD. Regarding the Morris water maze, compared to the control group, the acupuncture group showed a shorter escape latency [SMD = -2.23, 95% CI (-2.89, -1.57); I 2 = 79.2%] (P < 0.05), longer duration in platform quadrant [SMD = 2.34, 95% CI (1.44, 3.23); I 2 = 81.7%] (P < 0.05), and increased platform crossing number [SMD = 2.79, 95% CI (2.06, 3.53); I 2 = 71.9%] (P < 0.05). Conclusion Acupuncture may reduce neuroinflammation in AD by modulating cytokine expression. This modulation significantly improved cognitive function in animal models of AD. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022354878.
Collapse
|
3
|
Yang H, Zeng F, Luo Y, Zheng C, Ran C, Yang J. Curcumin Scaffold as a Multifunctional Tool for Alzheimer's Disease Research. Molecules 2022; 27:molecules27123879. [PMID: 35745002 PMCID: PMC9227459 DOI: 10.3390/molecules27123879] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative disorders, which is caused by multi-factors and characterized by two histopathological hallmarks: amyloid-β (Aβ) plaques and neurofibrillary tangles of Tau proteins. Thus, researchers have been devoting tremendous efforts to developing and designing new molecules for the early diagnosis of AD and curative purposes. Curcumin and its scaffold have fluorescent and photochemical properties. Mounting evidence showed that curcumin scaffold had neuroprotective effects on AD such as anti-amyloidogenic, anti-inflammatory, anti-oxidative and metal chelating. In this review, we summarized different curcumin derivatives and analyzed the in vitro and in vivo results in order to exhibit the applications in AD diagnosis, therapeutic monitoring and therapy. The analysis results showed that, although curcumin and its analogues have some disadvantages such as short wavelength and low bioavailability, these shortcomings can be conquered by modifying the structures. Curcumin scaffold still has the potential to be a multifunctional tool for AD research, including AD diagnosis and therapy.
Collapse
Affiliation(s)
- Haijun Yang
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China; (H.Y.); (Y.L.)
| | - Fantian Zeng
- School of Public Health, Xiamen University, Xiamen 361000, China;
| | - Yunchun Luo
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China; (H.Y.); (Y.L.)
| | - Chao Zheng
- PET Center, School of Medicine, Yale University, New Haven, CT 06520, USA;
| | - Chongzhao Ran
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
- Correspondence: (C.R.); (J.Y.)
| | - Jian Yang
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China; (H.Y.); (Y.L.)
- Correspondence: (C.R.); (J.Y.)
| |
Collapse
|
4
|
Albrecht DS, Sagare A, Pachicano M, Sweeney MD, Toga A, Zlokovic B, Chui H, Joe E, Schneider L, Morris JC, Benzinger T, Pa J. Early neuroinflammation is associated with lower amyloid and tau levels in cognitively normal older adults. Brain Behav Immun 2021; 94:299-307. [PMID: 33486003 PMCID: PMC8793040 DOI: 10.1016/j.bbi.2021.01.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 12/15/2022] Open
Abstract
CNS inflammation is a key factor in Alzheimer's Disease (AD), but its relation to pathological Aβ, tau, and APOE4 is poorly understood, particularly prior to the onset of cognitive symptoms. To better characterize early relationships between inflammation, APOE4, and AD pathology, we assessed correlations between cerebrospinal fluid (CSF) inflammatory markers and brain levels of Aβ and tau in cognitively normal older adults. Each participant received a lumbar puncture to collect and quantify CSF levels of TNFα, IL-6, IL-8, and IL-10, a T1-weighted MRI, and PET scanning with [18F]flortaucipir (FTP; n = 57), which binds to tau tangles and/or [18F]florbetapir (FBP; n = 58), which binds to Aβ. Parallel voxelwise regressions assessed relationships between each CSF inflammatory marker and FTP and FBP SUVR, as well as APOE4*CSF inflammation interactions. Unexpectedly, we detected significant negative associations between regional Aβ and tau PET uptake and CSF inflammatory markers. For Aβ PET, we detected negative associations with CSF IL-6 and IL-8 in regions known to show early accumulation of Aβ (i.e. lateral and medial frontal lobes). For tau PET, negative relationships were observed with CSF TNFα and IL-8, predominantly in regions known to exhibit early tau accumulation (i.e. medial temporal lobe). In subsequent analyses, significant interactions between APOE4 status and IL-8 on Aβ and tau PET levels were observed in spatially distinct regions from those showing CSF-Aβ/tau relationships. Results from the current cross-sectional study support previous findings that neuroinflammation may be protective against AD pathology at a given stage of the disease, and extend these findings to a cognitively normal aging population. This study provides new insight into a dynamic relationship between neuroinflammation and AD pathology and may have implications for whom and when neuroinflammatory therapies may be appropriate.
Collapse
Affiliation(s)
- Daniel S. Albrecht
- Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Abhay Sagare
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Maricarmen Pachicano
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Melanie D. Sweeney
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Arthur Toga
- Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Berislav Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Helena Chui
- Alzheimer Disease Research Center, Department of Neurology, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Elizabeth Joe
- Alzheimer Disease Research Center, Department of Neurology, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - Lon Schneider
- Alzheimer Disease Research Center, Department of Neurology, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States
| | - John C. Morris
- Department of Neurology, Department of Radiology, and Division of Biostatistics, Washington University School of Medicine, St Louis, MO, United States
| | - Tammie Benzinger
- Department of Neurology, Department of Radiology, and Division of Biostatistics, Washington University School of Medicine, St Louis, MO, United States
| | - Judy Pa
- Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States; Alzheimer Disease Research Center, Department of Neurology, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, United States.
| |
Collapse
|
5
|
Alasmari F, Alshammari MA, Alasmari AF, Alanazi WA, Alhazzani K. Neuroinflammatory Cytokines Induce Amyloid Beta Neurotoxicity through Modulating Amyloid Precursor Protein Levels/Metabolism. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3087475. [PMID: 30498753 PMCID: PMC6222241 DOI: 10.1155/2018/3087475] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/19/2018] [Accepted: 10/11/2018] [Indexed: 01/06/2023]
Abstract
Neuroinflammation has been observed in association with neurodegenerative diseases including Alzheimer's disease (AD). In particular, a positive correlation has been documented between neuroinflammatory cytokine release and the progression of the AD, which suggests these cytokines are involved in AD pathophysiology. A histological hallmark of the AD is the presence of beta-amyloid (Aβ) plaques and tau neurofibrillary tangles. Beta-amyloid is generated by the sequential cleavage of beta (β) and gamma (γ) sites in the amyloid precursor protein (APP) by β- and γ-secretase enzymes and its accumulation can result from either a decreased Aβ clearance or increased metabolism of APP. Previous studies reported that neuroinflammatory cytokines reduce the efflux transport of Aβ, leading to elevated Aβ concentrations in the brain. However, less is known about the effects of neuroinflammatory mediators on APP expression and metabolism. In this article, we review the modulatory role of neuroinflammatory cytokines on APP expression and metabolism, including their effects on β- and γ-secretase enzymes.
Collapse
Affiliation(s)
- Fawaz Alasmari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Musaad A. Alshammari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah F. Alasmari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Wael A. Alanazi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Alhazzani
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| |
Collapse
|
6
|
Amyloid precursor protein modulates macrophage phenotype and diet-dependent weight gain. Sci Rep 2017; 7:43725. [PMID: 28262782 PMCID: PMC5338020 DOI: 10.1038/srep43725] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/26/2017] [Indexed: 02/07/2023] Open
Abstract
It is well known that mutations in the gene coding for amyloid precursor protein are responsible for autosomal dominant forms of Alzheimer’s disease. Proteolytic processing of the protein leads to a number of metabolites including the amyloid beta peptide. Although brain amyloid precursor protein expression and amyloid beta production are associated with the pathophysiology of Alzheimer’s disease, it is clear that amyloid precursor protein is expressed in numerous cell types and tissues. Here we demonstrate that amyloid precursor protein is involved in regulating the phenotype of both adipocytes and peripheral macrophages and is required for high fat diet-dependent weight gain in mice. These data suggest that functions of this protein include modulation of the peripheral immune system and lipid metabolism. This biology may have relevance not only to the pathophysiology of Alzheimer’s disease but also diet-associated obesity.
Collapse
|
7
|
Epigenetics in Alzheimer's Disease: Perspective of DNA Methylation. Mol Neurobiol 2017; 55:1026-1044. [PMID: 28092081 DOI: 10.1007/s12035-016-0357-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 12/28/2016] [Indexed: 12/12/2022]
Abstract
Research over the years has shown that causes of Alzheimer's disease are not well understood, but over the past years, the involvement of epigenetic mechanisms in the developing memory formation either under pathological or physiological conditions has become clear. The term epigenetics represents the heredity of changes in phenotype that are independent of altered DNA sequences. Different studies validated that cytosine methylation of genomic DNA decreases with age in different tissues of mammals, and therefore, the role of epigenetic factors in developing neurological disorders in aging has been under focus. In this review, we summarized and reviewed the involvement of different epigenetic mechanisms especially the DNA methylation in Alzheimer's disease (AD), late-onset Alzheimer's disease (LOAD), familial Alzheimer's disease (FAD), and autosomal dominant Alzheimer's disease (ADAD). Down to the minutest of details, we tried to discuss the methylation patterns like mitochondrial DNA methylation and ribosomal DNA (rDNA) methylation. Additionally, we mentioned some therapeutic approaches related to epigenetics, which could provide a potential cure for AD. Moreover, we reviewed some recent studies that validate DNA methylation as a potential biomarker and its role in AD. We hope that this review will provide new insights into the understanding of AD pathogenesis from the epigenetic perspective especially from the perspective of DNA methylation.
Collapse
|
8
|
Domingues C, Cruz e Silva OA, Henriques AG. Impact of Cytokines and Chemokines on Alzheimer's Disease Neuropathological Hallmarks. Curr Alzheimer Res 2017; 14:870-882. [PMID: 28317487 PMCID: PMC5543563 DOI: 10.2174/1567205014666170317113606] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 02/08/2017] [Accepted: 03/13/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common neurodegenerative disorder, neuropathologically characterized by aggregates of β-amyloid peptides, which deposit as senile plaques, and of TAU protein, which forms neurofibrillary tangles. It is now widely accepted that neuroinflammation is implicated in AD pathogenesis. METHOD Indeed, inflammatory mediators, such as cytokines and chemokines (chemotactic cytokines) can impact on the Alzheimer´s amyloid precursor protein by affecting its expression levels and amyloidogenic processing and/or β -amyloid aggregation. Additionally, cytokines and chemokines can influence kinases' activities, leading to abnormal TAU phosphorylation. To date there is no cure for AD, but several therapeutic strategies have been directed to prevent neuroinflammation. Anti-inflammatory, but also anti-amyloidogenic compounds, such as flavonoids were shown to favourably modulate some pathological events associated with neurodegeneration. CONCLUSION This review focuses on the role of cytokines and chemokines in AD-associated pathologies, and summarizes the potential anti-inflammatory therapeutic approaches aimed at preventing or slowing down disease progression.
Collapse
Affiliation(s)
- Catarina Domingues
- Neurosciences and Signalling Laboratory, Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193Aveiro, Portugal
| | - Odete A.B. Cruz e Silva
- Neurosciences and Signalling Laboratory, Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193Aveiro, Portugal
| | - Ana Gabriela Henriques
- Neurosciences and Signalling Laboratory, Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193Aveiro, Portugal
| |
Collapse
|
9
|
Imaging hydrogen peroxide in Alzheimer's disease via cascade signal amplification. Sci Rep 2016; 6:35613. [PMID: 27762326 PMCID: PMC5071891 DOI: 10.1038/srep35613] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/28/2016] [Indexed: 01/08/2023] Open
Abstract
In brains of Alzheimer’s disease (AD), reactive oxygen species (ROS) levels are significantly higher than that of healthy brains. Evidence suggests that, during AD onset and progression, a vicious cycle revolves around amyloid beta (Aβ) production, aggregation, plaque formation, microglia/immunological responses, inflammation, and ROS production. In this cycle, ROS species play a central role, and H2O2 is one of the most important ROS species. In this report, we have designed a fluorescent imaging probe CRANAD-88, which is capable of cascade amplifying near infrared fluorescence (NIRF) signals at three levels upon interacting with H2O2 in AD brains. We demonstrated that the amplification was feasible in vitro and in vivo. Remarkably, we showed that, for the first time, it was feasible to monitor the changes of H2O2 concentrations in AD brains before and after treatment with an H2O2 scavenger. Our method opens new revenues to investigate H2O2 in AD brains and can be very instructive for drug development.
Collapse
|
10
|
Atwood CS, Bowen RL. The endocrine dyscrasia that accompanies menopause and andropause induces aberrant cell cycle signaling that triggers re-entry of post-mitotic neurons into the cell cycle, neurodysfunction, neurodegeneration and cognitive disease. Horm Behav 2015; 76:63-80. [PMID: 26188949 PMCID: PMC4807861 DOI: 10.1016/j.yhbeh.2015.06.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 06/23/2015] [Accepted: 06/23/2015] [Indexed: 12/26/2022]
Abstract
This article is part of a Special Issue "SBN 2014". Sex hormones are physiological factors that promote neurogenesis during embryonic and fetal development. During childhood and adulthood these hormones support the maintenance of brain structure and function via neurogenesis and the formation of dendritic spines, axons and synapses required for the capture, processing and retrieval of information (memories). Not surprisingly, changes in these reproductive hormones that occur with menopause and during andropause are strongly correlated with neurodegeneration and cognitive decline. In this connection, much evidence now indicates that Alzheimer's disease (AD) involves aberrant re-entry of post-mitotic neurons into the cell cycle. Cell cycle abnormalities appear very early in the disease, prior to the appearance of plaques and tangles, and explain the biochemical, neuropathological and cognitive changes observed with disease progression. Intriguingly, a recent animal study has demonstrated that induction of adult neurogenesis results in the loss of previously encoded memories while decreasing neurogenesis after memory formation during infancy mitigated forgetting. Here we review the biochemical, epidemiological and clinical evidence that alterations in sex hormone signaling associated with menopause and andropause drive the aberrant re-entry of post-mitotic neurons into an abortive cell cycle that leads to neurite retraction, neuron dysfunction and neuron death. When the reproductive axis is in balance, gonadotropins such as luteinizing hormone (LH), and its fetal homolog, human chorionic gonadotropin (hCG), promote pluripotent human and totipotent murine embryonic stem cell and neuron proliferation. However, strong evidence supports menopausal/andropausal elevations in the LH:sex steroid ratio as driving aberrant mitotic events. These include the upregulation of tumor necrosis factor; amyloid-β precursor protein processing towards the production of mitogenic Aβ; and the activation of Cdk5, a key regulator of cell cycle progression and tau phosphorylation (a cardinal feature of both neurogenesis and neurodegeneration). Cognitive and biochemical studies confirm the negative consequences of a high LH:sex steroid ratio on dendritic spine density and human cognitive performance. Prospective epidemiological and clinical evidence in humans supports the premise that rebalancing the ratio of circulating gonadotropins:sex steroids reduces the incidence of AD. Together, these data support endocrine dyscrasia and the subsequent loss of cell cycle control as an important etiological event in the development of neurodegenerative diseases including AD, stroke and Parkinson's disease.
Collapse
Affiliation(s)
- Craig S Atwood
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA; Geriatric Research, Education and Clinical Center, Veterans Administration Hospital, Madison, WI 53705, USA; School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, 6027 WA, Australia.
| | - Richard L Bowen
- OTB Research, 217 Calhoun St, Unit 1, Charleston, SC 29401, USA
| |
Collapse
|
11
|
Cai Z, Xiao M, Chang L, Yan LJ. Role of insulin resistance in Alzheimer's disease. Metab Brain Dis 2015; 30:839-51. [PMID: 25399337 DOI: 10.1007/s11011-014-9631-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 11/07/2014] [Indexed: 01/01/2023]
Abstract
A critical role of insulin resistance (IR) in Alzheimer's disease (AD) includes beta-amyloid (Aβ) production and accumulation, the formation of neurofibrillary tangles (NFTs), failure of synaptic transmission and neuronal degeneration. Aβ is sequentially cleavaged from APP by two proteolytic enzymes: β-secretase and γ-secretase. IR could regulate Aβ production via enhancing β- and γ-secretase activity. Meanwhile, IR induces oxidative stress and inflammation in the brain which contributes to Aβ and tau pathology. Aβ accumulation can enhance IR through Aβ-mediated inflammation and oxidative stress. IR is a possible linking between amyloid plaques and NFTs pathology via oxidative stress and neuroinflammation. Additionally, IR could disrupt acetylcholine activity, and accelerate axon degeneration and failures in axonal transport, and lead to cognitive impairment in AD. Preclinical and clinical studies have supported that insulin could be useful in the treatment of AD. Thus, an effective measure to inhibit IR may be a novel drug target in AD.
Collapse
Affiliation(s)
- Zhiyou Cai
- Department of Neurology, Renmin Hospital, Hubei University of Medicine, Shiyan Renmin Hospital, No. 39 Chaoyang Middle Road, Shiyan, 442000, Hubei Province, People's Republic of China,
| | | | | | | |
Collapse
|
12
|
Lardenoije R, Iatrou A, Kenis G, Kompotis K, Steinbusch HWM, Mastroeni D, Coleman P, Lemere CA, Hof PR, van den Hove DLA, Rutten BPF. The epigenetics of aging and neurodegeneration. Prog Neurobiol 2015; 131:21-64. [PMID: 26072273 PMCID: PMC6477921 DOI: 10.1016/j.pneurobio.2015.05.002] [Citation(s) in RCA: 246] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 05/13/2015] [Accepted: 05/13/2015] [Indexed: 12/14/2022]
Abstract
Epigenetics is a quickly growing field encompassing mechanisms regulating gene expression that do not involve changes in the genotype. Epigenetics is of increasing relevance to neuroscience, with epigenetic mechanisms being implicated in brain development and neuronal differentiation, as well as in more dynamic processes related to cognition. Epigenetic regulation covers multiple levels of gene expression; from direct modifications of the DNA and histone tails, regulating the level of transcription, to interactions with messenger RNAs, regulating the level of translation. Importantly, epigenetic dysregulation currently garners much attention as a pivotal player in aging and age-related neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, where it may mediate interactions between genetic and environmental risk factors, or directly interact with disease-specific pathological factors. We review current knowledge about the major epigenetic mechanisms, including DNA methylation and DNA demethylation, chromatin remodeling and non-coding RNAs, as well as the involvement of these mechanisms in normal aging and in the pathophysiology of the most common neurodegenerative diseases. Additionally, we examine the current state of epigenetics-based therapeutic strategies for these diseases, which either aim to restore the epigenetic homeostasis or skew it to a favorable direction to counter disease pathology. Finally, methodological challenges of epigenetic investigations and future perspectives are discussed.
Collapse
Affiliation(s)
- Roy Lardenoije
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Artemis Iatrou
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Gunter Kenis
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Konstantinos Kompotis
- Center for Integrative Genomics, University of Lausanne, Genopode Building, 1015 Lausanne-Dorigny, Switzerland
| | - Harry W M Steinbusch
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Diego Mastroeni
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands; L.J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA
| | - Paul Coleman
- L.J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA
| | - Cynthia A Lemere
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Daniel L A van den Hove
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands; Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany
| | - Bart P F Rutten
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands.
| |
Collapse
|
13
|
Wan Z, Mah D, Simtchouk S, Kluftinger A, Little JP. Role of amyloid β in the induction of lipolysis and secretion of adipokines from human adipose tissue. Adipocyte 2015; 4:212-6. [PMID: 26257989 DOI: 10.4161/21623945.2014.985020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/19/2014] [Accepted: 11/03/2014] [Indexed: 11/19/2022] Open
Abstract
Amyloid-β (Aβ) peptide, which is generated from proteolytic cleavage of amyloid precursor protein (APP), is a key molecule involved in the pathology of Alzheimer disease. Both APP and Aβ peptides are expressed in adipose tissue, however it is currently unclear whether Aβ can affect the key functions of adipose tissue. We aimed to explore whether Aβ affected lipolysis and adipokine secretion in cultured human adipose tissue. We found that Aβ25-35, which contains the main functional domain of the Aβ, stimulated lipolysis via PKA and ERK1/2-dependent pathways and that Aβ25-35 induced leptin and IL-6 secretion. It is concluded that Aβ peptide exerts functional effects on adipose tissue that may lead to increased release of free fatty acids and pro-inflammatory adipokines.
Collapse
|
14
|
Jeong JI, Kim J, Kim KM, Choi I, Pratley RE, Lee YH. Altered gene expression of amyloid precursor protein in the adipose tissue and brain of obese mice fed with long-term high-fat diet and streptozotocin-induced diabetic mice. Anim Cells Syst (Seoul) 2014. [DOI: 10.1080/19768354.2014.940383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
15
|
Wang J, Yu JT, Tan MS, Jiang T, Tan L. Epigenetic mechanisms in Alzheimer's disease: implications for pathogenesis and therapy. Ageing Res Rev 2013; 12:1024-41. [PMID: 23688931 DOI: 10.1016/j.arr.2013.05.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/08/2013] [Indexed: 12/14/2022]
Abstract
The vast majority of Alzheimer's disease (AD) are late-onset forms (LOAD) likely due to the interplay of environmental influences and individual genetic susceptibility. Epigenetic mechanisms, including DNA methylation, histone modifications and non-coding RNAs, constitute dynamic intracellular processes for translating environmental stimuli into modifications in gene expression. Over the past decade it has become increasingly clear that epigenetic mechanisms play a pivotal role in aging the pathogenesis of AD. Here, we provide a review of the major mechanisms for epigenetic modification and how they are reportedly altered in aging and AD. Moreover, we also consider how aberrant epigenetic modifications may lead to AD pathogenesis, and we review the therapeutic potential of epigenetic treatments for AD.
Collapse
Affiliation(s)
- Jun Wang
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, China
| | | | | | | | | |
Collapse
|
16
|
Clark IA, Vissel B. Treatment implications of the altered cytokine-insulin axis in neurodegenerative disease. Biochem Pharmacol 2013; 86:862-71. [PMID: 23939185 DOI: 10.1016/j.bcp.2013.07.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 11/15/2022]
Abstract
The disappointments of a series of large anti-amyloid trials have brought home the point that until the driving force behind Alzheimer's disease, and the way it causes harm, are firmly established and accepted, researchers will remain ill-equipped to find a way to treat patients successfully. The origin of inflammation in neurodegenerative diseases is still an open question. We champion and expand the argument that a shift in intracellular location of α-synuclein, thereby moving a key methylation enzyme from the nucleus, provides global hypomethylation of patients' cerebral DNA that, through being sensed by TLR9, initiates production of the cytokines that drive these cerebral inflammatory states. After providing a background on the relevant inflammatory cytokines, this commentary then discusses many of the known alternatives to the primary amyloid argument of the pathogenesis of Alzheimer's disease, and the treatment approaches they provide. A key point to appreciate is the weight of evidence that inflammatory cytokines, largely through increasing insulin resistance and thereby reducing the strength of the ubiquitously important signaling mediated by insulin, bring together most of these treatments under development for neurodegenerative disease under the one roof. Moreover, the principles involved apply to a wide range of inflammatory diseases on both sides of the blood brain barrier.
Collapse
Affiliation(s)
- Ian A Clark
- Research School of Biology, Australian National University, Canberra, Australia.
| | | |
Collapse
|
17
|
Daulatzai MA. Neurotoxic Saboteurs: Straws that Break the Hippo’s (Hippocampus) Back Drive Cognitive Impairment and Alzheimer’s Disease. Neurotox Res 2013; 24:407-59. [DOI: 10.1007/s12640-013-9407-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/06/2013] [Accepted: 06/17/2013] [Indexed: 12/29/2022]
|
18
|
Wright AL, Zinn R, Hohensinn B, Konen LM, Beynon SB, Tan RP, Clark IA, Abdipranoto A, Vissel B. Neuroinflammation and neuronal loss precede Aβ plaque deposition in the hAPP-J20 mouse model of Alzheimer's disease. PLoS One 2013; 8:e59586. [PMID: 23560052 PMCID: PMC3613362 DOI: 10.1371/journal.pone.0059586] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/15/2013] [Indexed: 12/20/2022] Open
Abstract
Recent human trials of treatments for Alzheimer's disease (AD) have been largely unsuccessful, raising the idea that treatment may need to be started earlier in the disease, well before cognitive symptoms appear. An early marker of AD pathology is therefore needed and it is debated as to whether amyloid-βAβ? plaque load may serve this purpose. We investigated this in the hAPP-J20 AD mouse model by studying disease pathology at 6, 12, 24 and 36 weeks. Using robust stereological methods, we found there is no neuron loss in the hippocampal CA3 region at any age. However loss of neurons from the hippocampal CA1 region begins as early as 12 weeks of age. The extent of neuron loss increases with age, correlating with the number of activated microglia. Gliosis was also present, but plateaued during aging. Increased hyperactivity and spatial memory deficits occurred at 16 and 24 weeks. Meanwhile, the appearance of plaques and oligomeric Aβ were essentially the last pathological changes, with significant changes only observed at 36 weeks of age. This is surprising given that the hAPP-J20 AD mouse model is engineered to over-expresses Aβ. Our data raises the possibility that plaque load may not be the best marker for early AD and suggests that activated microglia could be a valuable marker to track disease progression.
Collapse
MESH Headings
- Age Factors
- Alzheimer Disease/diagnosis
- Alzheimer Disease/genetics
- Alzheimer Disease/metabolism
- Alzheimer Disease/pathology
- Amyloid beta-Protein Precursor/genetics
- Amyloid beta-Protein Precursor/metabolism
- Animals
- Biomarkers/metabolism
- CA1 Region, Hippocampal/metabolism
- CA1 Region, Hippocampal/pathology
- CA3 Region, Hippocampal/cytology
- CA3 Region, Hippocampal/metabolism
- Cell Count
- Disease Models, Animal
- Early Diagnosis
- Gene Expression
- Gliosis/diagnosis
- Gliosis/genetics
- Gliosis/metabolism
- Gliosis/pathology
- Humans
- Inflammation
- Male
- Memory Disorders/diagnosis
- Memory Disorders/genetics
- Memory Disorders/metabolism
- Memory Disorders/pathology
- Mice
- Mice, Transgenic
- Microglia/metabolism
- Microglia/pathology
- Neurons/metabolism
- Neurons/pathology
- Plaque, Amyloid/diagnosis
- Plaque, Amyloid/genetics
- Plaque, Amyloid/metabolism
- Plaque, Amyloid/pathology
- Stereotaxic Techniques
Collapse
Affiliation(s)
- Amanda L. Wright
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Raphael Zinn
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Barbara Hohensinn
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Lyndsey M. Konen
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
| | - Sarah B. Beynon
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
| | - Richard P. Tan
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
| | - Ian A. Clark
- Research School of Biology, Australian National University, Canberra, Australia
| | - Andrea Abdipranoto
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
| | - Bryce Vissel
- Neurodegenerative Disorders, Garvan Institute of Medical Research, Neuroscience Department, Sydney, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| |
Collapse
|
19
|
Clark I, Atwood C, Bowen R, Paz-Filho G, Vissel B. Tumor necrosis factor-induced cerebral insulin resistance in Alzheimer's disease links numerous treatment rationales. Pharmacol Rev 2012; 64:1004-26. [PMID: 22966039 DOI: 10.1124/pr.112.005850] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The evident limitations of the amyloid theory of the pathogenesis of Alzheimer's disease are increasingly putting alternatives in the spotlight. We argue here that a number of independently developing approaches to therapy-including specific and nonspecific anti-tumor necrosis factor (TNF) agents, apolipoprotein E mimetics, leptin, intranasal insulin, the glucagon-like peptide-1 mimetics and glycogen synthase kinase-3 (GSK-3) antagonists-are all part of an interlocking chain of events. All these approaches inform us that inflammation and thence cerebral insulin resistance constitute the pathway on which to focus for a successful clinical outcome in treating this disease. The key link in this chain presently absent is a recognition by Alzheimer's research community of the long-neglected history of TNF induction of insulin resistance. When this is incorporated into the bigger picture, it becomes evident that the interventions we discuss are not competing alternatives but equally valid approaches to correcting different parts of the same pathway to Alzheimer's disease. These treatments can be expected to be at least additive, and conceivably synergistic, in effect. Thus the inflammation, insulin resistance, GSK-3, and mitochondrial dysfunction hypotheses are not opposing ideas but stages of the same fundamental, overarching, pathway of Alzheimer's disease pathogenesis. The insight this provides into progenitor cells, including those involved in adult neurogenesis, is a key part of this approach. This pathway also has therapeutic implications for other circumstances in which brain TNF is pathologically increased, such as stroke, traumatic brain injury, and the infectious disease encephalopathies.
Collapse
Affiliation(s)
- Ian Clark
- Division of Medical Science and Biochemistry, Research School of Biology, Australian National University, Canberra ACT, Australia.
| | | | | | | | | |
Collapse
|
20
|
Mutant amyloid precursor protein differentially alters adipose biology under obesogenic and non-obesogenic conditions. PLoS One 2012; 7:e43193. [PMID: 22912823 PMCID: PMC3422309 DOI: 10.1371/journal.pone.0043193] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 07/20/2012] [Indexed: 12/25/2022] Open
Abstract
Mutations in amyloid precursor protein (APP) have been most intensely studied in brain tissue for their link to Alzheimer’s disease (AD) pathology. However, APP is highly expressed in a variety of tissues including adipose tissue, where APP is also known to exhibit increased expression in response to obesity. In our current study, we analyzed the effects of mutant APP (E693Q, D694N, K670N/M671L) expression toward multiple aspects of adipose tissue homeostasis. These data reveal significant hypoleptinemia, decreased adiposity, and reduced adipocyte size in response to mutant APP, and this was fully reversed upon high fat diet administration. Additionally, mutant APP was observed to significantly exacerbate insulin resistance, triglyceride elevations, and macrophage infiltration of adipose tissue in response to a high fat diet. Taken together, these data have significant implications for linking mutant APP expression to adipose tissue dysfunction and global changes in endocrine and metabolic function under both obesogenic and non-obesogenic conditions.
Collapse
|
21
|
Puig KL, Combs CK. Expression and function of APP and its metabolites outside the central nervous system. Exp Gerontol 2012; 48:608-11. [PMID: 22846461 DOI: 10.1016/j.exger.2012.07.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/12/2012] [Accepted: 07/13/2012] [Indexed: 11/24/2022]
Abstract
Amyloid precursor protein (APP) derived amyloid beta (Aβ) peptides have been extensively investigated in Alzheimer's disease pathology of the brain. However, the function of full length APP in the central nervous system remains unclear. Even less is known about the function of this ubiquitously expressed protein and its metabolites outside of the central nervous system. This review summarizes key aspects of the current understanding of the expression and function of APP and its proteolytic fragments in specific non-neuronal tissues.
Collapse
Affiliation(s)
- Kendra L Puig
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
| | | |
Collapse
|
22
|
Clark IA, Atwood CS. Is TNF a link between aging-related reproductive endocrine dyscrasia and Alzheimer's disease? J Alzheimers Dis 2012; 27:691-9. [PMID: 21891866 DOI: 10.3233/jad-2011-110887] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This commentary addresses a novel mechanism by which aging-related changes in reproductive hormones could mediate their action in the brain. It presents the evidence that dyotic endocrine signals modulate the expression of tumor necrosis factor (TNF) and related cytokines, and that these cytokines are a functionally important downstream link mediating neurodegeneration and dysfunction. This convergence of dyotic signaling on TNF-mediated degeneration and dysfunction has important implications for understanding the pathophysiology of AD, stroke, and traumatic brain disease, and also for the treatment of these diseases.
Collapse
Affiliation(s)
- Ian A Clark
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
| | | |
Collapse
|
23
|
Amyloid precursor protein and proinflammatory changes are regulated in brain and adipose tissue in a murine model of high fat diet-induced obesity. PLoS One 2012; 7:e30378. [PMID: 22276186 PMCID: PMC3261903 DOI: 10.1371/journal.pone.0030378] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 12/19/2011] [Indexed: 11/23/2022] Open
Abstract
Background Middle age obesity is recognized as a risk factor for Alzheimer's disease (AD) although a mechanistic linkage remains unclear. Based upon the fact that obese adipose tissue and AD brains are both areas of proinflammatory change, a possible common event is chronic inflammation. Since an autosomal dominant form of AD is associated with mutations in the gene coding for the ubiquitously expressed transmembrane protein, amyloid precursor protein (APP) and recent evidence demonstrates increased APP levels in adipose tissue during obesity it is feasible that APP serves some function in both disease conditions. Methodology/Principal Findings To determine whether diet-induced obesity produced proinflammatory changes and altered APP expression in brain versus adipose tissue, 6 week old C57BL6/J mice were maintained on a control or high fat diet for 22 weeks. Protein levels and cell-specific APP expression along with markers of inflammation and immune cell activation were compared between hippocampus, abdominal subcutaneous fat and visceral pericardial fat. APP stimulation-dependent changes in macrophage and adipocyte culture phenotype were examined for comparison to the in vivo changes. Conclusions/Significance Adipose tissue and brain from high fat diet fed animals demonstrated increased TNF-α and microglial and macrophage activation. Both brains and adipose tissue also had elevated APP levels localizing to neurons and macrophage/adipocytes, respectively. APP agonist antibody stimulation of macrophage cultures increased specific cytokine secretion with no obvious effects on adipocyte culture phenotype. These data support the hypothesis that high fat diet-dependent obesity results in concomitant pro-inflammatory changes in brain and adipose tissue that is characterized, in part, by increased levels of APP that may be contributing specifically to inflammatory changes that occur.
Collapse
|
24
|
Epigenetic mechanisms in Alzheimer's disease. Neurobiol Aging 2011; 32:1161-80. [PMID: 21482442 DOI: 10.1016/j.neurobiolaging.2010.08.017] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 07/20/2010] [Accepted: 08/07/2010] [Indexed: 12/20/2022]
Abstract
Epigenetic modifications help orchestrate sweeping developmental, aging, and disease-causing changes in phenotype by altering transcriptional activity in multiple genes spanning multiple biologic pathways. Although previous epigenetic research has focused primarily on dividing cells, particularly in cancer, recent studies have shown rapid, dynamic, and persistent epigenetic modifications in neurons that have significant neuroendocrine, neurophysiologic, and neurodegenerative consequences. Here, we provide a review of the major mechanisms for epigenetic modification and how they are reportedly altered in aging and Alzheimer's disease (AD). Because of their reach across the genome, epigenetic mechanisms may provide a unique integrative framework for the pathologic diversity and complexity of AD.
Collapse
|
25
|
|