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Bickel MA, Csik B, Gulej R, Ungvari A, Nyul-Toth A, Conley SM. Cell non-autonomous regulation of cerebrovascular aging processes by the somatotropic axis. Front Endocrinol (Lausanne) 2023; 14:1087053. [PMID: 36755922 PMCID: PMC9900125 DOI: 10.3389/fendo.2023.1087053] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/04/2023] [Indexed: 01/24/2023] Open
Abstract
Age-related cerebrovascular pathologies, ranging from cerebromicrovascular functional and structural alterations to large vessel atherosclerosis, promote the genesis of vascular cognitive impairment and dementia (VCID) and exacerbate Alzheimer's disease. Recent advances in geroscience, including results from studies on heterochronic parabiosis models, reinforce the hypothesis that cell non-autonomous mechanisms play a key role in regulating cerebrovascular aging processes. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) exert multifaceted vasoprotective effects and production of both hormones is significantly reduced in aging. This brief overview focuses on the role of age-related GH/IGF-1 deficiency in the development of cerebrovascular pathologies and VCID. It explores the mechanistic links among alterations in the somatotropic axis, specific macrovascular and microvascular pathologies (including capillary rarefaction, microhemorrhages, impaired endothelial regulation of cerebral blood flow, disruption of the blood brain barrier, decreased neurovascular coupling, and atherogenesis) and cognitive impairment. Improved understanding of cell non-autonomous mechanisms of vascular aging is crucial to identify targets for intervention to promote cerebrovascular and brain health in older adults.
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Affiliation(s)
- Marisa A. Bickel
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Boglarka Csik
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Rafal Gulej
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Anna Ungvari
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Adam Nyul-Toth
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Department of Public Health, Semmelweis University, Budapest, Hungary
- Institute of Biophysics, Biological Research Centre, Eötvös Lorand Research Network (ELKH), Szeged, Hungary
| | - Shannon M. Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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Wang D, Ye J, Shi R, Zhao B, Liu Z, Lin W, Liu X. Dietary protein and amino acid restriction: Roles in metabolic health and aging-related diseases. Free Radic Biol Med 2022; 178:226-242. [PMID: 34890767 DOI: 10.1016/j.freeradbiomed.2021.12.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 12/13/2022]
Abstract
The prevalence of obesity is a worldwide phenomenon in all age groups and is associated with aging-related diseases such as type 2 diabetes, as well metabolic and cardiovascular diseases. The use of dietary restriction (DR) while avoiding malnutrition has many profound beneficial effects on aging and metabolic health, and dietary protein or specific amino acid (AA) restrictions, rather than overall calorie intake, are considered to play key roles in the effects of DR on host health. Whereas comprehensive reviews of the underlying mechanisms are limited, protein restriction and methionine (Met) restriction improve metabolic health and aging-related neurodegenerative diseases, and may be associated with FGF21, mTOR and autophagy, improved mitochondrial function and oxidative stress. Circulating branched-chain amino acids (BCAAs) are inversely correlated with metabolic health, and BCAAs and leucine (Leu) restriction promote metabolic homeostasis in rodents. Although tryptophan (Trp) restriction extends the lifespan of rodents, the Trp-restricted diet is reported to increase inflammation in aged mice, while severe Trp restriction has side effects such as anorexia. Furthermore, inadequate protein intake in the elderly increases the risk of muscle-centric health. Therefore, the restriction of specific AAs may be an effective and executable dietary manipulation for metabolic and aging-related health in humans, which warrants further investigation to elucidate the underlying mechanisms.
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Affiliation(s)
- Danna Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Jin Ye
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Renjie Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Beita Zhao
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Zhigang Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Wei Lin
- Department of Neurosurgery, Xijing Institute of Clinical Neuroscience, Xijing Hospital, Air Force Medical University, Xi'an, Shanxi, China.
| | - Xuebo Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, China.
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Molecular Characteristics of Amyloid Precursor Protein (APP) and Its Effects in Cancer. Int J Mol Sci 2021; 22:ijms22094999. [PMID: 34066808 PMCID: PMC8125876 DOI: 10.3390/ijms22094999] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/02/2021] [Accepted: 05/06/2021] [Indexed: 12/16/2022] Open
Abstract
Amyloid precursor protein (APP) is a type 1 transmembrane glycoprotein, and its homologs amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2) are highly conserved in mammals. APP and APLP are known to be intimately involved in the pathogenesis and progression of Alzheimer's disease and to play important roles in neuronal homeostasis and development and neural transmission. APP and APLP are also expressed in non-neuronal tissues and are overexpressed in cancer cells. Furthermore, research indicates they are involved in several cancers. In this review, we examine the biological characteristics of APP-related family members and their roles in cancer.
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Wang B, Lin X, Zhou J, Xie C, Li C, Dong R, Zhang G, Sun X, Wang M, Bi Y. Insulin-like growth factor-1 improves postoperative cognitive dysfunction following splenectomy in aged rats. Exp Ther Med 2021; 21:215. [PMID: 33574912 PMCID: PMC7818527 DOI: 10.3892/etm.2021.9647] [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: 08/13/2019] [Accepted: 09/29/2020] [Indexed: 11/15/2022] Open
Abstract
Postoperative cognitive dysfunction (POCD) is a serious complication following anesthesia and operations in aged patients undergoing surgical intervention. It is characterized by temporary or permanent cognitive decline, memory impairment and deterioration in language comprehension and social adaption ability. Therefore, the development of POCD prevention and treatment tools has become an area of interest. The current study assessed the therapeutic effects of insulin-like growth factor-1 (IGF-1) on POCD in aged rats and explored the underlying mechanisms. Model rats underwent splenectomy under 1.5-2% isoflurane and mechanical ventilation. IGF-1 (50 µg/kg) was diluted in normal saline and administered by abdominal hypodermic injection daily from the operation to day 7 post-operation. Following splenectomy, the animals showed marked cognitive impairment as determined by the Morris water maze test. Hippocampal protein levels of amyloid precursor protein (APP), β-site APP-cleaving enzyme-1 (BACE-1), amyloid-β (Aβ), capase3, Bax and Bcl-2 were assessed by immunoblotting. Neuronal apoptosis in the hippocampus was analyzed using a TUNEL assay. The results demonstrated that the levels of APP, BACE-1, Aβ, caspase3 and Bax were increased following splenectomy, while the levels of Bcl2 were reduced at days 1, 3 and 7 post-operation in aged rats. However, IGF-1 downregulated APP, BACE-1, Aβ, capase3 and Bax, and upregulated Bcl2 at these time points following splenectomy. TUNEL staining revealed that administration of IGF-1 significantly reduced neuronal apoptosis in the hippocampal CA1 region following splenectomy. These results indicated that IGF-1 decreased Aβ-protein production and inhibited neuronal apoptosis in the hippocampus following splenectomy, subsequently alleviating POCD.
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Affiliation(s)
- Bin Wang
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Xu Lin
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Jiahui Zhou
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Chunhui Xie
- Department of Anesthesiology, Weifang Medical University, Weifang, Shandong 261042, P.R. China
| | - Chuan Li
- Department of Anesthesiology, Weifang Medical University, Weifang, Shandong 261042, P.R. China
| | - Rui Dong
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Gaofeng Zhang
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Xiaopeng Sun
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Mingshan Wang
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Yanlin Bi
- Department of Anesthesiology, Qingdao Municipal Hospital Affiliated to Qingdao University, Qingdao, Shandong 266071, P.R. China
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Herrero-Labrador R, Trueba-Saiz A, Martinez-Rachadell L, Fernandez de Sevilla ME, Zegarra-Valdivia JA, Pignatelli J, Diaz-Pacheco S, Fernandez AM, Torres Aleman I. Circulating Insulin-Like Growth Factor I is Involved in the Effect of High Fat Diet on Peripheral Amyloid β Clearance. Int J Mol Sci 2020; 21:ijms21249675. [PMID: 33352990 PMCID: PMC7766006 DOI: 10.3390/ijms21249675] [Citation(s) in RCA: 4] [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: 10/22/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 01/11/2023] Open
Abstract
Obesity is a risk factor for Alzheimer’s disease (AD), but underlying mechanisms are not clear. We analyzed peripheral clearance of amyloid β (Aβ) in overweight mice because its systemic elimination may impact brain Aβ load, a major landmark of AD pathology. We also analyzed whether circulating insulin-like growth factor I (IGF-I) intervenes in the effects of overweight as this growth factor modulates brain Aβ clearance and is increased in the serum of overweight mice. Overweight mice showed increased Aβ accumulation by the liver, the major site of elimination of systemic Aβ, but unaltered brain Aβ levels. We also found that Aβ accumulation by hepatocytes is stimulated by IGF-I, and that mice with low serum IGF-I levels show reduced liver Aβ accumulation—ameliorated by IGF-I administration, and unchanged brain Aβ levels. In the brain, IGF-I favored the association of its receptor (IGF-IR) with the Aβ precursor protein (APP), and at the same time, stimulated non-amyloidogenic processing of APP in astrocytes, as indicated by an increased sAPPα/sAPPβ ratio after IGF-I treatment. Since serum IGF-I enters into the brain in an activity-dependent manner, we analyzed in overweight mice the effect of brain activation by environmental enrichment (EE) on brain IGF-IR phosphorylation and its association to APP, as a readout of IGF-I activity. After EE, significantly reduced brain IGF-IR phosphorylation and APP/IGF-IR association were found in overweight mice as compared to lean controls. Collectively, these results indicate that a high-fat diet influences peripheral clearance of Aβ without affecting brain Aβ load. Increased serum IGF-I likely contributes to enhanced peripheral Aβ clearance in overweight mice, without affecting brain Aβ load probably because its brain entrance is reduced.
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Affiliation(s)
- Raquel Herrero-Labrador
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
| | - Angel Trueba-Saiz
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
| | - Laura Martinez-Rachadell
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
| | - Mᵃ Estrella Fernandez de Sevilla
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
| | - Jonathan A. Zegarra-Valdivia
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
- Universidad Nacional de San Agustín de Arequipa, 04001 Arequipa, Peru
| | - Jaime Pignatelli
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
| | - Sonia Diaz-Pacheco
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
| | - Ana M. Fernandez
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
| | - Ignacio Torres Aleman
- Cajal Institute, CSIC, 28002 Madrid, Spain; (R.H.-L.); (A.T.-S.); (L.M.-R.); (M.E.F.d.S.); (J.A.Z.-V.); (J.P.); (S.D.-P.); (A.M.F.)
- Ciberned, 28029 Madrid, Spain
- Correspondence:
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Yamamoto F, Taniguchi K, Mamada N, Tamaoka A, Kametani F, Lakshmana MK, Araki W. TFEB-mediated Enhancement of the Autophagy-lysosomal Pathway Dually Modulates the Process of Amyloid β-Protein Generation in Neurons. Neuroscience 2019; 402:11-22. [PMID: 30677488 DOI: 10.1016/j.neuroscience.2019.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 01/08/2019] [Accepted: 01/11/2019] [Indexed: 12/28/2022]
Abstract
Abnormalities of the autophagy-lysosomal pathway (ALP) have been implicated in the pathology of Alzheimer's disease (AD). Activation of TFEB (transcription factor EB), a master regulator of the ALP, leads to ALP facilitation. The present study sought to clarify whether TFEB-mediated ALP facilitation influences the process of amyloid β-protein (Aβ) generation in neurons. TFEB was overexpressed in mature rat primary cortical neurons via recombinant adenoviruses, without (basal conditions) or with co-overexpression of wild-type amyloid precursor protein (APP) or its β-C-terminal fragment (β-CTF). We confirmed that TFEB overexpression upregulated the lysosomal proteins, cathepsin D and LAMP-1. In TFEB-expressing neurons, protein levels of ADAM10 were profoundly increased, whereas those of APP, BACE1, or γ-secretase complex proteins were unaffected. However, TFEB did not affect ADAM10 mRNA levels. TFEB overexpression had different effects on Aβ production depending on the expression level of APP or β-CTF: TFEB slightly decreased Aβ secretion under basal conditions; clearly increased α-CTF levels and marginally increased β-CTF levels with modest increases in secreted Aβ in APP-expressing neurons; and caused a remarkable increase in β-CTF levels with a significant increase in secreted Aβ in β-CTF-expressing neurons. Inhibition of proteasomes, but not lysosomes, markedly increased β-CTF levels in β-CTF-expressing neurons. These results collectively indicate that TFEB modulates Aβ production not only by increasing α-secretase processing of APP through ADAM10 upregulation but also by augmenting β-CTF levels possibly via altered proteasome-mediated catabolism. Thus, TFEB-mediated ALP enhancement appears to have dual, but opposite, effects on Aβ production in neurons.
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Affiliation(s)
- Fumiko Yamamoto
- Department of Demyelinating Disease and Aging, National Institute of Neuroscience, NCNP, Kodaira, Tokyo 187-8502, Japan; Department of Neurology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kaori Taniguchi
- Department of Demyelinating Disease and Aging, National Institute of Neuroscience, NCNP, Kodaira, Tokyo 187-8502, Japan
| | - Naomi Mamada
- Department of Neurology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Akira Tamaoka
- Department of Neurology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Fuyuki Kametani
- Department of Dementia and Higher Brain Function, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506, Japan
| | - Madepalli K Lakshmana
- Section of Neurobiology, Torrey Pines Institute for Molecular Studies, Port Saint Lucie, Florida 34987, United States
| | - Wataru Araki
- Department of Demyelinating Disease and Aging, National Institute of Neuroscience, NCNP, Kodaira, Tokyo 187-8502, Japan.
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Ohshima Y, Iwata K, Ibi M, Matsumoto M, Katsuyama M, Yabe-Nishimura C. Nicotine and methyl vinyl ketone, major components of cigarette smoke extracts, increase protective amyloid-β peptides in cells harboring amyloid-β precursor protein. J Toxicol Sci 2018; 43:257-266. [PMID: 29618714 DOI: 10.2131/jts.43.257] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The increased ratio of longer amyloid-β (Aβ1-42)/shorter amyloid-β (Aβ1-40) peptides, generated from amyloid precursor protein (APP), is known to promote the development of Alzheimer's disease (AD). To investigate the role of smoking in Aβ production, we determined the production of Aβ species in the presence of nicotine or methyl vinyl ketone (MVK), major components of cigarette smoke extracts, in Flp-In™ T-REx™-293 (T-REx293) cells harboring a single copy of human APP. While treatment with nicotine or MVK did not affect the amount of APP, the levels of Aβ1-40 in the culture media were significantly increased. On the other hand, the levels of Aβ1-42 were unaltered by nicotine or MVK treatment. The Aβ1-42/Aβ1-40 ratio was therefore attenuated by cigarette smoke extracts. Similar results were obtained in T-REx293 cells harboring APP of Swedish- or London-type mutation linked to familial AD. T-REx293 cells expressed the nicotinic acetylcholine receptor (nAchR) and tubocurarine, an nAChR antagonist, completely blocked the effects of nicotine. Treatment with nicotine significantly elevated cellular levels of β-secretase that cleaves APP prior to Aβ generation. Taken together, a protective role of nicotine against AD pathology was suggested by enhanced extracellular Aβ1-40 production, which may suppress Aβ fibrillogenesis.
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Affiliation(s)
- Yoichi Ohshima
- Department of Pharmacology, Kyoto Prefectural University of Medicine.,Department of Neurology, Kyoto Yamashiro General Medical Center
| | - Kazumi Iwata
- Department of Pharmacology, Kyoto Prefectural University of Medicine
| | - Masakazu Ibi
- Department of Pharmacology, Kyoto Prefectural University of Medicine
| | - Misaki Matsumoto
- Department of Pharmacology, Kyoto Prefectural University of Medicine
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Amyloid precursor protein and amyloid precursor-like protein 2 in cancer. Oncotarget 2017; 7:19430-44. [PMID: 26840089 PMCID: PMC4991393 DOI: 10.18632/oncotarget.7103] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/23/2016] [Indexed: 12/22/2022] Open
Abstract
Amyloid precursor protein (APP) and its family members amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2) are type 1 transmembrane glycoproteins that are highly conserved across species. The transcriptional regulation of APP and APLP2 is similar but not identical, and the cleavage of both proteins is regulated by phosphorylation. APP has been implicated in Alzheimer's disease causation, and in addition to its importance in neurology, APP is deregulated in cancer cells. APLP2 is likewise overexpressed in cancer cells, and APLP2 and APP are linked to increased tumor cell proliferation, migration, and invasion. In this present review, we discuss the unfolding account of these APP family members’ roles in cancer progression and metastasis.
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Amyloid-β transmission or unexamined bias? Nature 2016; 537:E7-9. [PMID: 27629649 DOI: 10.1038/nature19086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 06/21/2016] [Indexed: 11/08/2022]
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10
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Nieto-Estévez V, Defterali Ç, Vicario-Abejón C. IGF-I: A Key Growth Factor that Regulates Neurogenesis and Synaptogenesis from Embryonic to Adult Stages of the Brain. Front Neurosci 2016; 10:52. [PMID: 26941597 PMCID: PMC4763060 DOI: 10.3389/fnins.2016.00052] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 02/05/2016] [Indexed: 12/28/2022] Open
Abstract
The generation of neurons in the adult mammalian brain requires the activation of quiescent neural stem cells (NSCs). This activation and the sequential steps of neuron formation from NSCs are regulated by a number of stimuli, which include growth factors. Insulin-like growth factor-I (IGF-I) exert pleiotropic effects, regulating multiple cellular processes depending on their concentration, cell type, and the developmental stage of the animal. Although IGF-I expression is relatively high in the embryonic brain its levels drop sharply in the adult brain except in neurogenic regions, i.e., the hippocampus (HP) and the subventricular zone-olfactory bulb (SVZ-OB). By contrast, the expression of IGF-IR remains relatively high in the brain irrespective of the age of the animal. Evidence indicates that IGF-I influences NSC proliferation and differentiation into neurons and glia as well as neuronal maturation including synapse formation. Furthermore, recent studies have shown that IGF-I not only promote adult neurogenesis by regulating NSC number and differentiation but also by influencing neuronal positioning and migration as described during SVZ-OB neurogenesis. In this article we will revise and discuss the actions reported for IGF-I signaling in a variety of in vitro and in vivo models, focusing on the maintenance and proliferation of NSCs/progenitors, neurogenesis, and neuron integration in synaptic circuits.
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Affiliation(s)
- Vanesa Nieto-Estévez
- Consejo Superior de Investigaciones Científicas (CSIC), Instituto CajalMadrid, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)Madrid, Spain
| | - Çağla Defterali
- Consejo Superior de Investigaciones Científicas (CSIC), Instituto CajalMadrid, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)Madrid, Spain
| | - Carlos Vicario-Abejón
- Consejo Superior de Investigaciones Científicas (CSIC), Instituto CajalMadrid, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)Madrid, Spain
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Bloemer J, Bhattacharya S, Amin R, Suppiramaniam V. Impaired insulin signaling and mechanisms of memory loss. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 121:413-49. [PMID: 24373245 DOI: 10.1016/b978-0-12-800101-1.00013-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Insulin is secreted from the β-cells of the pancreas and helps maintain glucose homeostasis. Although secreted peripherally, insulin also plays a profound role in cognitive function. Increasing evidence suggests that insulin signaling in the brain is necessary to maintain health of neuronal cells, promote learning and memory, decrease oxidative stress, and ultimately increase neuronal survival. This chapter summarizes the different facets of insulin signaling necessary for learning and memory and additionally explores the association between cognitive impairment and central insulin resistance. The role of impaired insulin signaling in the advancement of cognitive dysfunction is relevant to the current debate of whether the shared pathophysiological mechanisms between diabetes and cognitive impairment implicate a direct relationship. Here, we summarize a vast amount of literature that suggests a strong association between impaired brain insulin signaling and cognitive impairment.
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Affiliation(s)
- Jenna Bloemer
- Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, Alabama, USA
| | - Subhrajit Bhattacharya
- Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, Alabama, USA
| | - Rajesh Amin
- Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, Alabama, USA
| | - Vishnu Suppiramaniam
- Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, Alabama, USA
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Agbemenyah HY, Agis-Balboa RC, Burkhardt S, Delalle I, Fischer A. Insulin growth factor binding protein 7 is a novel target to treat dementia. Neurobiol Dis 2013; 62:135-43. [PMID: 24075854 DOI: 10.1016/j.nbd.2013.09.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/13/2013] [Accepted: 09/17/2013] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly but effective therapeutic strategies to treat AD are not yet available. This is also due to the fact that the pathological mechanisms that drive the pathogenesis of sporadic AD are still not sufficiently understood and may differ on the individual level. Several risk factors such as altered insulin-like peptide (ILP) signaling have been linked to AD and modulating the ILP system has been discussed as a potential therapeutic avenue. Here we show that insulin-like growth factor binding protein 7 (IGFBP7), a protein that attenuates the function of ILPs, is up-regulated in the brains of AD patients and in a mouse model for AD via a process that involves altered DNA-methylation and coincides with decreased ILP signaling. Mimicking the AD-situation in wild type mice, by increasing hippocampal IGFBP7 levels leads to impaired memory consolidation. Consistently, inhibiting IGFBP7 function in mice that develop AD-like memory impairment reinstates associative learning behavior. These data suggest that IGFBP7 is a critical regulator of memory consolidation and might be used as a biomarker for AD. Targeting IGFBP7 could be a novel therapeutic avenue for the treatment of AD patients.
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Affiliation(s)
- Hope Y Agbemenyah
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Grisebachstr. 5, 37077 Göttingen, Germany
| | - Roberto C Agis-Balboa
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Grisebachstr. 5, 37077 Göttingen, Germany
| | - Susanne Burkhardt
- German Center for Neurodegenerative Diseases (DZNE) Göttingen, Grisebachstr. 5, 37077 Göttingen, Germany
| | - Ivana Delalle
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Andre Fischer
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Grisebachstr. 5, 37077 Göttingen, Germany; German Center for Neurodegenerative Diseases (DZNE) Göttingen, Grisebachstr. 5, 37077 Göttingen, Germany.
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Statins reduce amyloid β-peptide production by modulating amyloid precursor protein maturation and phosphorylation through a cholesterol-independent mechanism in cultured neurons. Neurochem Res 2012; 38:589-600. [PMID: 23269484 DOI: 10.1007/s11064-012-0956-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 12/17/2012] [Accepted: 12/19/2012] [Indexed: 01/19/2023]
Abstract
Statins, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, have been reported to attenuate amyloid-β peptide (Aβ) production in various cellular models. However, the mechanisms by which statins affect neuronal Aβ production have not yet been clarified. Here, we investigated this issue in rat primary cortical neurons using two statins, pitavastatin (PV) and atorvastatin (AV). Treatment of neurons with 0.2-2.5 μM PV or AV for 4 days induced a concentration- and time-dependent reduction in the secretion of both Aβ40 and Aβ42. Moreover, Western blot analyses of cell lysates showed that treatment with PV or AV significantly reduced expression levels of the mature form of amyloid precursor protein (APP) and Thr668-phosphorylated APP (P-APP), but not immature form of APP; the decreases in P-APP levels were more notable than those of mature APP levels. The statin treatment did not alter expression of BACE1 (β-site APP-cleaving enzyme 1) or γ-secretase complex proteins (presenilin 1, nicastrin, APH-1, and PEN-2). In neurons overexpressing APP via recombinant adenoviruses, PV or AV similarly reduced Aβ secretion and the levels of mature APP and P-APP. Statins also markedly reduced cellular cholesterol content in neurons in a concentration-dependent manner. Co-treatment with mevalonate reversed the statin-induced decreases in Aβ secretion and mature APP and P-APP levels, whereas co-treatment with cholesterol did not, despite recovery of cellular cholesterol levels. Finally, cell-surface biotinylation experiments revealed that both statins significantly reduced the levels of cell-surface P-APP without changing those of cell surface mature APP. These results suggest that statins reduce Aβ production by selectively modulating APP maturation and phosphorylation through a mechanism independent of cholesterol reduction in cultured neurons.
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Spencer P, Fry RC, Kisby GE. Unraveling 50-Year-Old Clues Linking Neurodegeneration and Cancer to Cycad Toxins: Are microRNAs Common Mediators? Front Genet 2012; 3:192. [PMID: 23060898 PMCID: PMC3460211 DOI: 10.3389/fgene.2012.00192] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/09/2012] [Indexed: 01/19/2023] Open
Abstract
Recognition of overlapping molecular signaling activated by a chemical trigger of cancer and neurodegeneration is new, but the path to this discovery has been long and potholed. Six conferences (1962–1972) examined the puzzling neurotoxic and carcinogenic properties of a then-novel toxin [cycasin: methylazoxymethanol (MAM)-β-d-glucoside] in cycad plants used traditionally for food and medicine on Guam where a complex neurodegenerative disease plagued the indigenous population. Affected families showed combinations of amyotrophic lateral sclerosis (ALS), parkinsonism (P), and/or a dementia (D) akin to Alzheimer’s disease (AD). Modernization saw declining disease rates on Guam and remarkable changes in clinical phenotype (ALS was replaced by P-D and then by D) and in two genetically distinct ALS-PDC-affected populations (Kii-Japan, West Papua-Indonesia) that used cycad seed medicinally. MAM forms DNA lesions – repaired by O6-methylguanine methyltransferase (MGMT) – that perturb mouse brain development and induce malignant tumors in peripheral organs. The brains of young adult MGMT-deficient mice given a single dose of MAM show DNA lesion-linked changes in cell-signaling pathways associated with miRNA-1, which is implicated in colon, liver, and prostate cancers, and in neurological disease, notably AD. MAM is metabolized to formaldehyde, a human carcinogen. Formaldehyde-responsive miRNAs predicted to modulate MAM-associated genes in the brains of MGMT-deficient mice include miR-17-5p and miR-18d, which regulate genes involved in tumor suppression, DNA repair, amyloid deposition, and neurotransmission. These findings marry cycad-associated ALS-PDC with colon, liver, and prostate cancer; they also add to evidence linking changes in microRNA status both to ALS, AD, and parkinsonism, and to cancer initiation and progression.
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Affiliation(s)
- Peter Spencer
- Global Health Center, Oregon Health and Science University Portland, OR, USA
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15
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Poirier R, Fernandez AM, Torres-Aleman I, Metzger F. Early brain amyloidosis in APP/PS1 mice with serum insulin-like growth factor-I deficiency. Neurosci Lett 2011; 509:101-4. [PMID: 22230888 DOI: 10.1016/j.neulet.2011.12.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 11/28/2011] [Accepted: 12/22/2011] [Indexed: 11/30/2022]
Abstract
The influence of insulin-like growth factor I (IGF-I) on the progression of Alzheimer's disease (AD) is discussed controversially. To help clarify the role of this circulating neurotrophic factor in brain amyloidosis, the major pathological trait in AD, we analyzed plaque formation in a mouse model of AD transgenic for human APP and PS1 mutations with reduced serum IGF-I levels (LIDAD mice). We found that brain amyloidosis in LIDAD mice appeared earlier than in AD mice, at 2 months of age, while attained comparable levels at 6 months. In parallel, early microgliosis was observed in LIDAD mice also at 2 months and remained exacerbated at 6 months. Collectively, these observations suggest a role of serum IGF-I in delaying early brain amyloidosis.
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Affiliation(s)
- R Poirier
- F. Hoffmann-LaRoche, CNS Pharma Research & Early Development, Basel, Switzerland
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The cycad genotoxin MAM modulates brain cellular pathways involved in neurodegenerative disease and cancer in a DNA damage-linked manner. PLoS One 2011; 6:e20911. [PMID: 21731631 PMCID: PMC3121718 DOI: 10.1371/journal.pone.0020911] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 05/16/2011] [Indexed: 02/02/2023] Open
Abstract
Methylazoxymethanol (MAM), the genotoxic metabolite of the cycad azoxyglucoside cycasin, induces genetic alterations in bacteria, yeast, plants, insects and mammalian cells, but adult nerve cells are thought to be unaffected. We show that the brains of adult C57BL6 wild-type mice treated with a single systemic dose of MAM acetate display DNA damage (O6-methyldeoxyguanosine lesions, O6-mG) that remains constant up to 7 days post-treatment. By contrast, MAM-treated mice lacking a functional gene encoding the DNA repair enzyme O6-mG DNA methyltransferase (MGMT) showed elevated O6-mG DNA damage starting at 48 hours post-treatment. The DNA damage was linked to changes in the expression of genes in cell-signaling pathways associated with cancer, human neurodegenerative disease, and neurodevelopmental disorders. These data are consistent with the established developmental neurotoxic and carcinogenic properties of MAM in rodents. They also support the hypothesis that early-life exposure to MAM-glucoside (cycasin) has an etiological association with a declining, prototypical neurodegenerative disease seen in Guam, Japan, and New Guinea populations that formerly used the neurotoxic cycad plant for food or medicine, or both. These findings suggest environmental genotoxins, specifically MAM, target common pathways involved in neurodegeneration and cancer, the outcome depending on whether the cell can divide (cancer) or not (neurodegeneration). Exposure to MAM-related environmental genotoxins may have relevance to the etiology of related tauopathies, notably, Alzheimer's disease.
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Chadwick W, Brenneman R, Martin B, Maudsley S. Complex and multidimensional lipid raft alterations in a murine model of Alzheimer's disease. Int J Alzheimers Dis 2010; 2010:604792. [PMID: 21151659 PMCID: PMC2997345 DOI: 10.4061/2010/604792] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 07/27/2010] [Indexed: 01/18/2023] Open
Abstract
Various animal models of Alzheimer's disease (AD) have been created to assist our appreciation of AD pathophysiology, as well as aid development of novel therapeutic strategies. Despite the discovery of mutated proteins that predict the development of AD, there are likely to be many other proteins also involved in this disorder. Complex physiological processes are mediated by coherent interactions of clusters of functionally related proteins. Synaptic dysfunction is one of the hallmarks of AD. Synaptic proteins are organized into multiprotein complexes in high-density membrane structures, known as lipid rafts. These microdomains enable coherent clustering of synergistic signaling proteins. We have used mass analytical techniques and multiple bioinformatic approaches to better appreciate the intricate interactions of these multifunctional proteins in the 3xTgAD murine model of AD. Our results show that there are significant alterations in numerous receptor/cell signaling proteins in cortical lipid rafts isolated from 3xTgAD mice.
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Affiliation(s)
- Wayne Chadwick
- Receptor Pharmacology Unit, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 21224, USA
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Araki W, Kametani F, Oda A, Tamaoka A. MEK inhibitors suppress β-amyloid production by altering the level of a β-C-terminal fragment of amyloid precursor protein in neuronal cells. FEBS Lett 2010; 584:3410-4. [DOI: 10.1016/j.febslet.2010.06.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 06/04/2010] [Accepted: 06/24/2010] [Indexed: 10/19/2022]
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Sun MK, Nelson TJ, Alkon DL. PKC and Insulin Pathways in Memory Storage: Targets for Synaptogenesis, Anti-apoptosis, and the Treatment of AD. DIABETES, INSULIN AND ALZHEIMER'S DISEASE 2010. [DOI: 10.1007/978-3-642-04300-0_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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