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Buck SA, Mabry SJ, Glausier JR, Banks-Tibbs T, Ward C, Kozel JG, Fu C, Fish KN, Lewis DA, Logan RW, Freyberg Z. Aging disrupts the coordination between mRNA and protein expression in mouse and human midbrain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.01.596950. [PMID: 38854057 PMCID: PMC11160743 DOI: 10.1101/2024.06.01.596950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Age-related dopamine (DA) neuron loss is a primary feature of Parkinson's disease. However, it remains unclear whether similar biological processes occur during healthy aging, albeit to a lesser degree. We therefore determined whether midbrain DA neurons degenerate during aging in mice and humans. In mice, we identified no changes in midbrain neuron numbers throughout aging. Despite this, we found age-related decreases in midbrain mRNA expression of tyrosine hydroxylase (Th), the rate limiting enzyme of DA synthesis. Among midbrain glutamatergic cells, we similarly identified age-related declines in vesicular glutamate transporter 2 (Vglut2) mRNA expression. In co-transmitting Th +/Vglut2 + neurons, Th and Vglut2 transcripts decreased with aging. Importantly, striatal Th and Vglut2 protein expression remained unchanged. In translating our findings to humans, we found no midbrain neurodegeneration during aging and identified age-related decreases in TH and VGLUT2 mRNA expression similar to mouse. Unlike mice, we discovered diminished density of striatal TH+ dopaminergic terminals in aged human subjects. However, TH and VGLUT2 protein expression were unchanged in the remaining striatal boutons. Finally, in contrast to Th and Vglut2 mRNA, expression of most ribosomal genes in Th + neurons was either maintained or even upregulated during aging. This suggests a homeostatic mechanism where age-related declines in transcriptional efficiency are overcome by ongoing ribosomal translation. Overall, we demonstrate species-conserved transcriptional effects of aging in midbrain dopaminergic and glutamatergic neurons that are not accompanied by marked cell death or lower striatal protein expression. This opens the door to novel therapeutic approaches to maintain neurotransmission and bolster neuronal resilience.
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Affiliation(s)
- Silas A. Buck
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Samuel J. Mabry
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jill R. Glausier
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tabitha Banks-Tibbs
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA, USA
- College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Caroline Ward
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jenesis Gayden Kozel
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chen Fu
- Department of Psychiatry, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kenneth N. Fish
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - David A. Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ryan W. Logan
- Department of Psychiatry, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
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2
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Labandeira-Garcia JL, Labandeira CM, Guerra MJ, Rodriguez-Perez AI. The role of the brain renin-angiotensin system in Parkinson´s disease. Transl Neurodegener 2024; 13:22. [PMID: 38622720 PMCID: PMC11017622 DOI: 10.1186/s40035-024-00410-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 03/22/2024] [Indexed: 04/17/2024] Open
Abstract
The renin-angiotensin system (RAS) was classically considered a circulating hormonal system that regulates blood pressure. However, different tissues and organs, including the brain, have a local paracrine RAS. Mutual regulation between the dopaminergic system and RAS has been observed in several tissues. Dysregulation of these interactions leads to renal and cardiovascular diseases, as well as progression of dopaminergic neuron degeneration in a major brain center of dopamine/angiotensin interaction such as the nigrostriatal system. A decrease in the dopaminergic function induces upregulation of the angiotensin type-1 (AT1) receptor activity, leading to recovery of dopamine levels. However, AT1 receptor overactivity in dopaminergic neurons and microglial cells upregulates the cellular NADPH-oxidase-superoxide axis and Ca2+ release, which mediate several key events in oxidative stress, neuroinflammation, and α-synuclein aggregation, involved in Parkinson's disease (PD) pathogenesis. An intraneuronal antioxidative/anti-inflammatory RAS counteracts the effects of the pro-oxidative AT1 receptor overactivity. Consistent with this, an imbalance in RAS activity towards the pro-oxidative/pro-inflammatory AT1 receptor axis has been observed in the substantia nigra and striatum of several animal models of high vulnerability to dopaminergic degeneration. Interestingly, autoantibodies against angiotensin-converting enzyme 2 and AT1 receptors are increased in PD models and PD patients and contribute to blood-brain barrier (BBB) dysregulation and nigrostriatal pro-inflammatory RAS upregulation. Therapeutic strategies addressed to the modulation of brain RAS, by AT1 receptor blockers (ARBs) and/or activation of the antioxidative axis (AT2, Mas receptors), may be neuroprotective for individuals with a high risk of developing PD or in prodromal stages of PD to reduce progression of the disease.
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Affiliation(s)
- Jose Luis Labandeira-Garcia
- Cellular and Molecular Neurobiology of Parkinson´S Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain.
- Networking Research Center On Neurodegenerative Diseases (CIBERNED), Madrid, Spain.
| | | | - Maria J Guerra
- Cellular and Molecular Neurobiology of Parkinson´S Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain
- Networking Research Center On Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Ana I Rodriguez-Perez
- Cellular and Molecular Neurobiology of Parkinson´S Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain.
- Networking Research Center On Neurodegenerative Diseases (CIBERNED), Madrid, Spain.
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3
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Rocha GS, Freire MAM, Paiva KM, Oliveira RF, Morais PLAG, Santos JR, Cavalcanti JRLP. The neurobiological effects of senescence on dopaminergic system: A comprehensive review. J Chem Neuroanat 2024; 137:102415. [PMID: 38521203 DOI: 10.1016/j.jchemneu.2024.102415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/26/2024] [Accepted: 03/15/2024] [Indexed: 03/25/2024]
Abstract
Over time, the body undergoes a natural, multifactorial, and ongoing process named senescence, which induces changes at the molecular, cellular, and micro-anatomical levels in many body systems. The brain, being a highly complex organ, is particularly affected by this process, potentially impairing its numerous functions. The brain relies on chemical messengers known as neurotransmitters to function properly, with dopamine being one of the most crucial. This catecholamine is responsible for a broad range of critical roles in the central nervous system, including movement, learning, cognition, motivation, emotion, reward, hormonal release, memory consolidation, visual performance, sexual drive, modulation of circadian rhythms, and brain development. In the present review, we thoroughly examine the impact of senescence on the dopaminergic system, with a primary focus on the classic delimitations of the dopaminergic nuclei from A8 to A17. We provide in-depth information about their anatomy and function, particularly addressing how senescence affects each of these nuclei.
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Affiliation(s)
- Gabriel S Rocha
- Behavioral and Evolutionary Neurobiology Laboratory, Federal University of Sergipe (UFS), Itabaiana, Brazil
| | - Marco Aurelio M Freire
- Behavioral and Evolutionary Neurobiology Laboratory, Federal University of Sergipe (UFS), Itabaiana, Brazil
| | - Karina M Paiva
- Laboratory of Experimental Neurology, State University of Rio Grande do Norte (UERN), Mossoró, Brazil
| | - Rodrigo F Oliveira
- Laboratory of Experimental Neurology, State University of Rio Grande do Norte (UERN), Mossoró, Brazil
| | - Paulo Leonardo A G Morais
- Laboratory of Experimental Neurology, State University of Rio Grande do Norte (UERN), Mossoró, Brazil
| | - José Ronaldo Santos
- Behavioral and Evolutionary Neurobiology Laboratory, Federal University of Sergipe (UFS), Itabaiana, Brazil
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4
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Alushaj E, Handfield-Jones N, Kuurstra A, Morava A, Menon RS, Owen AM, Sharma M, Khan AR, MacDonald PA. Increased iron in the substantia nigra pars compacta identifies patients with early Parkinson'sdisease: A 3T and 7T MRI study. Neuroimage Clin 2024; 41:103577. [PMID: 38377722 PMCID: PMC10944193 DOI: 10.1016/j.nicl.2024.103577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/19/2023] [Accepted: 02/07/2024] [Indexed: 02/22/2024]
Abstract
Degeneration in the substantia nigra (SN) pars compacta (SNc) underlies motor symptoms in Parkinson's disease (PD). Currently, there are no neuroimaging biomarkers that are sufficiently sensitive, specific, reproducible, and accessible for routine diagnosis or staging of PD. Although iron is essential for cellular processes, it also mediates neurodegeneration. MRI can localize and quantify brain iron using magnetic susceptibility, which could potentially provide biomarkers of PD. We measured iron in the SNc, SN pars reticulata (SNr), total SN, and ventral tegmental area (VTA), using quantitative susceptibility mapping (QSM) and R2* relaxometry, in PD patients and age-matched healthy controls (HCs). PD patients, diagnosed within five years of participation and HCs were scanned at 3T (22 PD and 23 HCs) and 7T (17 PD and 21 HCs) MRI. Midbrain nuclei were segmented using a probabilistic subcortical atlas. QSM and R2* values were measured in midbrain subregions. For each measure, groups were contrasted, with Age and Sex as covariates, and receiver operating characteristic (ROC) curve analyses were performed with repeated k-fold cross-validation to test the potential of our measures to classify PD patients and HCs. Statistical differences of area under the curves (AUCs) were compared using the Hanley-MacNeil method (QSM versus R2*; 3T versus 7T MRI). PD patients had higher QSM values in the SNc at both 3T (padj = 0.001) and 7T (padj = 0.01), but not in SNr, total SN, or VTA, at either field strength. No significant group differences were revealed using R2* in any midbrain region at 3T, though increased R2* values in SNc at 7T MRI were marginally significant in PDs compared to HCs (padj = 0.052). ROC curve analyses showed that SNc iron measured with QSM, distinguished early PD patients from HCs at the single-subject level with good diagnostic accuracy, using 3T (mean AUC = 0.83, 95 % CI = 0.82-0.84) and 7T (mean AUC = 0.80, 95 % CI = 0.79-0.81) MRI. Mean AUCs reported here are from averages of tests in the hold-out fold of cross-validated samples. The Hanley-MacNeil method demonstrated that QSM outperforms R2* in discriminating PD patients from HCs at 3T, but not 7T. There were no significant differences between 3T and 7T in diagnostic accuracy of QSM values in SNc. This study highlights the importance of segmenting midbrain subregions, performed here using a standardized atlas, and demonstrates high accuracy of SNc iron measured with QSM at 3T MRI in identifying early PD patients. QSM measures of SNc show potential for inclusion in neuroimaging diagnostic biomarkers of early PD. An MRI diagnostic biomarker of PD would represent a significant clinical advance.
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Affiliation(s)
- Erind Alushaj
- Department of Neuroscience, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 3K7, Canada; Western Institute for Neuroscience, Western University, London, Ontario N6A 3K7, Canada
| | - Nicholas Handfield-Jones
- Department of Neuroscience, Schulich School of Medicine and Dentistry, Western University, London, Ontario N6A 3K7, Canada; Western Institute for Neuroscience, Western University, London, Ontario N6A 3K7, Canada
| | - Alan Kuurstra
- Robarts Research Institute, Western University, London, Ontario N6A 3K7, Canada; Department of Medical Biophysics, Western University, London, Ontario N6A 3K7, Canada
| | - Anisa Morava
- School of Kinesiology, Faculty of Health Sciences, Western University, London, Ontario N6A 3K7, Canada
| | - Ravi S Menon
- Robarts Research Institute, Western University, London, Ontario N6A 3K7, Canada; Department of Medical Biophysics, Western University, London, Ontario N6A 3K7, Canada
| | - Adrian M Owen
- Western Institute for Neuroscience, Western University, London, Ontario N6A 3K7, Canada; Department of Physiology and Pharmacology, Western University, London, Ontario N6A 3K7, Canada
| | - Manas Sharma
- Department of Radiology, Western University, London, Ontario N6A 3K7, Canada; Department of Clinical Neurological Sciences, Western University, London, Ontario N6A 3K7, Canada
| | - Ali R Khan
- Robarts Research Institute, Western University, London, Ontario N6A 3K7, Canada; Department of Medical Biophysics, Western University, London, Ontario N6A 3K7, Canada
| | - Penny A MacDonald
- Western Institute for Neuroscience, Western University, London, Ontario N6A 3K7, Canada; Department of Clinical Neurological Sciences, Western University, London, Ontario N6A 3K7, Canada.
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5
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Coleman CR, Pallos J, Arreola-Bustos A, Wang L, Raftery D, Promislow DEL, Martin I. Natural Variation in Age-Related Dopamine Neuron Degeneration is Glutathione-Dependent and Linked to Life Span. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.12.580013. [PMID: 38405950 PMCID: PMC10888861 DOI: 10.1101/2024.02.12.580013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Aging is the biggest risk factor for Parkinson's disease (PD), suggesting that age-related changes in the brain promote dopamine neuron vulnerability. It is unclear, however, whether aging alone is sufficient to cause significant dopamine neuron loss and if so, how this intersects with PD-related neurodegeneration. Here, through examining a large collection of naturally varying Drosophila strains, we find a strong relationship between life span and age-related dopamine neuron loss. Naturally short-lived strains exhibit a loss of dopamine neurons but not generalized neurodegeneration, while long-lived strains retain dopamine neurons across age. Metabolomic profiling reveals lower glutathione levels in short-lived strains which is associated with elevated levels of reactive oxygen species (ROS), sensitivity to oxidative stress and vulnerability to silencing the familial PD gene parkin . Strikingly, boosting neuronal glutathione levels via glutamate-cysteine ligase (GCL) overexpression is sufficient to normalize ROS levels, extend life span and block dopamine neurons loss in short-lived backgrounds, demonstrating that glutathione deficiencies are central to neurodegenerative phenotypes associated with short longevity. These findings may be relevant to human PD pathogenesis, where glutathione depletion is frequently reported in idiopathic PD patient brain. Building on this evidence, we detect reduced levels of GCL catalytic and modulatory subunits in brain from PD patients harboring the LRRK2 G2019S mutation, implicating possible glutathione deficits in familial LRRK2-linked PD. Our study across Drosophila and human PD systems suggests that glutathione plays an important role in the influence of aging on PD neurodegeneration.
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Woulfe J, Munoz DG, Gray DA, Jinnah HA, Ivanova A. Inosine monophosphate dehydrogenase intranuclear inclusions are markers of aging and neuronal stress in the human substantia nigra. Neurobiol Aging 2024; 134:43-56. [PMID: 37992544 DOI: 10.1016/j.neurobiolaging.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/24/2023]
Abstract
We explored mechanisms involved in the age-dependent degeneration of human substantia nigra (SN) dopamine (DA) neurons. Owing to its important metabolic functions in post-mitotic neurons, we investigated the developmental and age-associated changes in the purine biosynthetic enzyme inosine monophosphate dehydrogenase (IMPDH). Tissue microarrays prepared from post-mortem samples of SN from 85 neurologically intact participants humans spanning the age spectrum were immunostained for IMPDH combined with other proteins. SN DA neurons contained two types of IMPDH structures: cytoplasmic IMPDH filaments and intranuclear IMPDH inclusions. The former were not age-restricted and may represent functional units involved in sustaining purine nucleotide supply in these highly metabolically active cells. The latter showed age-associated changes, including crystallization, features reminiscent of pathological inclusion bodies, and spatial associations with Marinesco bodies; structures previously associated with SN neuron dysfunction and death. We postulate dichotomous roles for these two subcellularly distinct IMPDH structures and propose a nucleus-based model for a novel mechanism of SN senescence that is independent of previously known neurodegeneration-associated proteins.
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Affiliation(s)
- John Woulfe
- Neuroscience Program, The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada.
| | - David G Munoz
- Li Ka Shing Knowledge Institute & Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine, St. Michael's Hospital, Unity Health, University of Toronto, Toronto, Ontario, Canada
| | - Douglas A Gray
- Center for Cancer Therapeutics, The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Hyder A Jinnah
- Departments of Neurology, Human Genetics & Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Alyona Ivanova
- The Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children and Neurosurgery Research Department, St. Michael's Hospital, Toronto Unity Health, Toronto, Ontario, Canada
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7
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Troyano-Rodriguez E, Blankenship HE, Handa K, Branch SY, Beckstead MJ. Preservation of dendritic D2 receptor transmission in substantia nigra dopamine neurons with age. Sci Rep 2023; 13:1025. [PMID: 36658269 PMCID: PMC9852430 DOI: 10.1038/s41598-023-28174-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 01/13/2023] [Indexed: 01/20/2023] Open
Abstract
Substantia nigra pars compacta (SNc) dopamine neurons are required for voluntary movement and reward learning, and advanced age is associated with motor and cognitive decline. In the midbrain, D2-type dopamine receptors located at dendrodendritic synapses between dopamine neurons control cell firing through G protein-activated potassium (GIRK) channels. We previously showed that aging disrupts dopamine neuron pacemaker firing in mice, but only in males. Here we show that the amplitude of D2-receptor inhibitory postsynaptic currents (D2-IPSCs) are moderately reduced in aged male mice. Local application of dopamine revealed a reduction in the amplitude of the D2-receptor currents in old males compared to young, pointing to a postsynaptic mechanism. Further experiments indicated that reduced D2 receptor signaling was not due to a general reduction in GIRK channel currents or degeneration of the dendritic arbor. Kinetic analysis showed no differences in D2-IPSC shape in old versus young mice or between sexes. Potentiation of D2-IPSCs by corticotropin releasing factor (CRF) was also not affected by age, indicating preservation of one mechanism of plasticity. These findings have implications for understanding dopamine transmission in aging, and reduced D2 receptor inhibition could contribute to increased susceptibility of males to SNc dopamine neuron degeneration in Parkinson's disease.
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Affiliation(s)
- Eva Troyano-Rodriguez
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Harris E Blankenship
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Kylie Handa
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Sarah Y Branch
- Department of Cellular and Integrative Physiology, University of Texas Health, San Antonio, TX, USA
| | - Michael J Beckstead
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
- Oklahoma City VA Medical Center, Oklahoma City, OK, USA.
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Knopper RW, Hansen B. Locus coeruleus and the defensive activation theory of rapid eye movement sleep: A mechanistic perspective. Front Neurosci 2023; 17:1094812. [PMID: 36908790 PMCID: PMC9995765 DOI: 10.3389/fnins.2023.1094812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023] Open
Abstract
The defensive activation theory (DAT) was recently proposed to explain the biological function of dreaming. Briefly, DAT states that dreams are primarily visual to prevent plastic take-over of an otherwise inactive visual cortex during sleep. Evidence to support the DAT revolve around the interplay between dream activity (REM%) and cortical plasticity found in evolutionary history, primate studies, and coinciding decline in human cortical plasticity and REM% with age. As the DAT may prove difficult to test experimentally, we investigate whether further support for the DAT can be found in the literature. Plasticity and REM sleep are closely linked to functions of the Locus Coeruleus (LC). We therefore review existing knowledge about the LC covering LC stability with age, and the role of the LC in the plasticity of the visual cortex. Recent studies show the LC to be more stable than previously believed and therefore, the LC likely supports the REM% and plasticity in the same manner throughout life. Based on this finding, we review the effect of aging on REM% and visual cortex plasticity. Here, we find that recent, weighty studies are not in complete agreement with the data originally provided as support for DAT. Results from these studies, however, are not in themselves irreconcilable with the DAT. Our findings therefore do not disprove the DAT. Importantly, we show that the LC is involved in all mechanisms central to the DAT. The LC may therefore provide an experimental window to further explore and test the DAT.
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Affiliation(s)
- Rasmus West Knopper
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, China
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Markussen NB, Knopper RW, Hasselholt S, Skoven CS, Nyengaard JR, Østergaard L, Hansen B. Locus coeruleus ablation in mice: protocol optimization, stereology and behavioral impact. Front Cell Neurosci 2023; 17:1138624. [PMID: 37180952 PMCID: PMC10172584 DOI: 10.3389/fncel.2023.1138624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
The Locus Coeruleus (LC) is in the brainstem and supplies key brain structures with noradrenaline, including the forebrain and hippocampus. The LC impacts specific behaviors such as anxiety, fear, and motivation, as well as physiological phenomena that impact brain functions in general, including sleep, blood flow regulation, and capillary permeability. Nevertheless, the short- and long-term consequences of LC dysfunction remain unclear. The LC is among the brain structures first affected in patients suffering from neurodegenerative diseases such as Parkinson's disease and Alzheimer's Disease, hinting that LC dysfunction may play a central role in disease development and progression. Animal models with modified or disrupted LC function are essential to further our understanding of LC function in the normal brain, the consequences of LC dysfunction, and its putative roles in disease development. For this, well-characterized animal models of LC dysfunction are needed. Here, we establish the optimal dose of selective neurotoxin N-(2-chloroethyl)-N-ethyl-bromo-benzylamine (DSP-4) for LC ablation. Using histology and stereology, we compare LC volume and neuron number in LC ablated (LCA) mice and controls to assess the efficacy of LC ablation with different numbers of DSP-4 injections. All LCA groups show a consistent decrease in LC cell count and LC volume. We then proceed to characterize the behavior of LCA mice using a light-dark box test, Barnes maze test, and non-invasive sleep-wakefulness monitoring. Behaviorally, LCA mice differ subtly from control mice, with LCA mice generally being more curious and less anxious compared to controls consistent with known LC function and projections. We note an interesting contrast in that control mice have varying LC size and neuron count but consistent behavior whereas LCA mice (as expected) have consistently sized LC but erratic behavior. Our study provides a thorough characterization of an LC ablation model, firmly consolidating it as a valid model system for the study of LC dysfunction.
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Affiliation(s)
- Nanna Bertin Markussen
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Rasmus West Knopper
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, China
| | - Stine Hasselholt
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christian Stald Skoven
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jens Randel Nyengaard
- Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Brian Hansen,
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Reddy DS, Abeygunaratne HN. Experimental and Clinical Biomarkers for Progressive Evaluation of Neuropathology and Therapeutic Interventions for Acute and Chronic Neurological Disorders. Int J Mol Sci 2022; 23:11734. [PMID: 36233034 PMCID: PMC9570151 DOI: 10.3390/ijms231911734] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/27/2022] Open
Abstract
This article describes commonly used experimental and clinical biomarkers of neuronal injury and neurodegeneration for the evaluation of neuropathology and monitoring of therapeutic interventions. Biomarkers are vital for diagnostics of brain disease and therapeutic monitoring. A biomarker can be objectively measured and evaluated as a proxy indicator for the pathophysiological process or response to therapeutic interventions. There are complex hurdles in understanding the molecular pathophysiology of neurological disorders and the ability to diagnose them at initial stages. Novel biomarkers for neurological diseases may surpass these issues, especially for early identification of disease risk. Validated biomarkers can measure the severity and progression of both acute neuronal injury and chronic neurological diseases such as epilepsy, migraine, Alzheimer's disease, Parkinson's disease, Huntington's disease, traumatic brain injury, amyotrophic lateral sclerosis, multiple sclerosis, and other brain diseases. Biomarkers are deployed to study progression and response to treatment, including noninvasive imaging tools for both acute and chronic brain conditions. Neuronal biomarkers are classified into four core subtypes: blood-based, immunohistochemical-based, neuroimaging-based, and electrophysiological biomarkers. Neuronal conditions have progressive stages, such as acute injury, inflammation, neurodegeneration, and neurogenesis, which can serve as indices of pathological status. Biomarkers are critical for the targeted identification of specific molecules, cells, tissues, or proteins that dramatically alter throughout the progression of brain conditions. There has been tremendous progress with biomarkers in acute conditions and chronic diseases affecting the central nervous system.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
- Institute of Pharmacology and Neurotherapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
- Intercollegiate School of Engineering Medicine, Texas A&M University, Houston, TX 77030, USA
- Department of Biomedical Engineering, College of Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Hasara Nethma Abeygunaratne
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
- Institute of Pharmacology and Neurotherapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
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Carving the senescent phenotype by the chemical reactivity of catecholamines: An integrative review. Ageing Res Rev 2022; 75:101570. [PMID: 35051644 DOI: 10.1016/j.arr.2022.101570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/11/2022] [Accepted: 01/15/2022] [Indexed: 11/21/2022]
Abstract
Macromolecules damaged by covalent modifications produced by chemically reactive metabolites accumulate in the slowly renewable components of living bodies and compromise their functions. Among such metabolites, catecholamines (CA) are unique, compared with the ubiquitous oxygen, ROS, glucose and methylglyoxal, in that their high chemical reactivity is confined to a limited set of cell types, including the dopaminergic and noradrenergic neurons and their direct targets, which suffer from CA propensities for autoxidation yielding toxic quinones, and for Pictet-Spengler reactions with carbonyl-containing compounds, which yield mitochondrial toxins. The functions progressively compromised because of that include motor performance, cognition, reward-driven behaviors, emotional tuning, and the neuroendocrine control of reproduction. The phenotypic manifestations of the resulting disorders culminate in such conditions as Parkinson's and Alzheimer's diseases, hypertension, sarcopenia, and menopause. The reasons to suspect that CA play some special role in aging accumulated since early 1970-ies. Published reviews address the role of CA hazardousness in the development of specific aging-associated diseases. The present integrative review explores how the bizarre discrepancy between CA hazardousness and biological importance could have emerged in evolution, how much does the chemical reactivity of CA contribute to the senescent phenotype in mammals, and what can be done with it.
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12
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Quijano A, Diaz-Ruiz C, Lopez-Lopez A, Villar-Cheda B, Muñoz A, Rodriguez-Perez AI, Labandeira-Garcia JL. Angiotensin Type-1 Receptor Inhibition Reduces NLRP3 Inflammasome Upregulation Induced by Aging and Neurodegeneration in the Substantia Nigra of Male Rodents and Primary Mesencephalic Cultures. Antioxidants (Basel) 2022; 11:antiox11020329. [PMID: 35204211 PMCID: PMC8868290 DOI: 10.3390/antiox11020329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/31/2022] [Accepted: 02/05/2022] [Indexed: 12/17/2022] Open
Abstract
The tissue renin–angiotensin system (RAS) has been shown to be involved in prooxidative and proinflammatory changes observed in aging and aging-related diseases such as dopaminergic degeneration in Parkinson’s disease (PD). We studied the activation of the NLRP3 inflammasome in the substantia nigra with aging and early stages of dopaminergic degeneration in PD models and, particularly, if the brain RAS, via its prooxidative proinflammatory angiotensin II (AngII) type 1 (AT1) receptors, mediates the inflammasome activation. Nigras from aged rats and mice and 6-hydroxydopamine PD models showed upregulation in transcription of inflammasome-related components (NLRP3, pro-IL1β and pro-IL18) and IL1β and IL18 protein levels, which was inhibited by the AT1 receptor antagonist candesartan. The role of the AngII/AT1 axis in inflammasome activation was further confirmed in rats intraventricularly injected with AngII, and in primary mesencephalic cultures treated with 6-hydroxydopamine, which showed inflammasome activation that was blocked by candesartan. Observations in the nigra of young and aged AT1 and AT2 knockout mice confirmed the major role of AT1 receptors in nigral inflammasome activation. In conclusion, the inflammasome is upregulated by aging and dopaminergic degeneration in the substantia nigra, possibly related with a decrease in dopamine levels, and it is mediated by the AngII/AT1 axis.
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Affiliation(s)
- Aloia Quijano
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
| | - Carmen Diaz-Ruiz
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
- Networking Research Center on Neurodegenerative Diseases (CiberNed), 28031 Madrid, Spain
| | - Andrea Lopez-Lopez
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
- Networking Research Center on Neurodegenerative Diseases (CiberNed), 28031 Madrid, Spain
| | - Begoña Villar-Cheda
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
- Networking Research Center on Neurodegenerative Diseases (CiberNed), 28031 Madrid, Spain
| | - Ana Muñoz
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
- Networking Research Center on Neurodegenerative Diseases (CiberNed), 28031 Madrid, Spain
| | - Ana I. Rodriguez-Perez
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
- Networking Research Center on Neurodegenerative Diseases (CiberNed), 28031 Madrid, Spain
| | - Jose L. Labandeira-Garcia
- Laboratory of Cellular and Molecular Neurobiology of Parkinson’s Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Department of Morphological Sciences, IDIS, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (A.Q.); (C.D.-R.); (A.L.-L.); (B.V.-C.); (A.M.); (A.I.R.-P.)
- Networking Research Center on Neurodegenerative Diseases (CiberNed), 28031 Madrid, Spain
- Correspondence: ; Tel.: +34-881-812223
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Carmichael K, Sullivan B, Lopez E, Sun L, Cai H. Diverse midbrain dopaminergic neuron subtypes and implications for complex clinical symptoms of Parkinson's disease. AGEING AND NEURODEGENERATIVE DISEASES 2021; 1. [PMID: 34532720 PMCID: PMC8442626 DOI: 10.20517/and.2021.07] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Parkinson’s disease (PD), the most common degenerative movement disorder, is clinically manifested with various motor and non-motor symptoms. Degeneration of midbrain substantia nigra pas compacta (SNc) dopaminergic neurons (DANs) is generally attributed to the motor syndrome. The underlying neuronal mechanisms of non-motor syndrome are largely unexplored. Besides SNc, midbrain ventral tegmental area (VTA) DANs also produce and release dopamine and modulate movement, reward, motivation, and memory. Degeneration of VTA DANs also occurs in postmortem brains of PD patients, implying an involvement of VTA DANs in PD-associated non-motor symptoms. However, it remains to be established that there is a distinct segregation of different SNc and VTA DAN subtypes in regulating different motor and non-motor functions, and that different DAN subpopulations are differentially affected by normal ageing or PD. Traditionally, the distinction among different DAN subtypes was mainly based on the location of cell bodies and axon terminals. With the recent advance of single cell RNA sequencing technology, DANs can be readily classified based on unique gene expression profiles. A combination of specific anatomic and molecular markers shows great promise to facilitate the identification of DAN subpopulations corresponding to different behavior modules under normal and disease conditions. In this review, we first summarize the recent progress in characterizing genetically, anatomically, and functionally diverse midbrain DAN subtypes. Then, we provide perspectives on how the preclinical research on the connectivity and functionality of DAN subpopulations improves our current understanding of cell-type and circuit specific mechanisms of the disease, which could be critically informative for designing new mechanistic treatments.
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Affiliation(s)
- Kathleen Carmichael
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.,The Graduate Partnership Program of NIH and Brown University, National Institutes of Health, Bethesda, MD 20892, USA
| | - Breanna Sullivan
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elena Lopez
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lixin Sun
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Huaibin Cai
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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14
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Beardmore R, Hou R, Darekar A, Holmes C, Boche D. The Locus Coeruleus in Aging and Alzheimer's Disease: A Postmortem and Brain Imaging Review. J Alzheimers Dis 2021; 83:5-22. [PMID: 34219717 PMCID: PMC8461706 DOI: 10.3233/jad-210191] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2021] [Indexed: 12/21/2022]
Abstract
The locus coeruleus (LC), a tiny nucleus in the brainstem and the principal site of noradrenaline synthesis, has a major role in regulating autonomic function, arousal, attention, and neuroinflammation. LC dysfunction has been linked to a range of disorders; however particular interest is given to the role it plays in Alzheimer's disease (AD). The LC undergoes significant neuronal loss in AD, thought to occur early in the disease process. While neuronal loss in the LC has also been suggested to occur in aging, this relationship is less clear as the findings have been contradictory. LC density has been suggested to be indicative of cognitive reserve and the evidence for these claims will be discussed. Recent imaging techniques allowing visualization of the LC in vivo using neuromelanin-sensitive MRI are developing our understanding of the role of LC in aging and AD. Tau pathology within the LC is evident at an early age in most individuals; however, the relationship between tau accumulation and neuronal loss and why some individuals then develop AD is not understood. Neuromelanin pigment accumulates within LC cells with age and is proposed to be toxic and inflammatory when released into the extracellular environment. This review will explore our current knowledge of the LC changes in both aging and AD from postmortem, imaging, and experimental studies. We will discuss the reasons behind the susceptibility of the LC to neuronal loss, with a focus on the role of extracellular neuromelanin and neuroinflammation caused by the dysfunction of the LC-noradrenaline pathway.
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Affiliation(s)
- Rebecca Beardmore
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Memory Assessment and Research Centre, Moorgreen Hospital, Southern Health Foundation Trust, Southampton, UK
| | - Ruihua Hou
- Clinical and Experimental Sciences, Department of Psychiatry, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Angela Darekar
- Department of Medical Physics, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Clive Holmes
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Memory Assessment and Research Centre, Moorgreen Hospital, Southern Health Foundation Trust, Southampton, UK
| | - Delphine Boche
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
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15
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Yu Y, Wu M, Zhang N, Yin H, Shu B, Duan W. A pilot study on searching for peri-nuclear NeuN-positive cells. PeerJ 2020; 8:e8254. [PMID: 31938576 PMCID: PMC6953339 DOI: 10.7717/peerj.8254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 11/20/2019] [Indexed: 02/02/2023] Open
Abstract
The aim of this study was to find out neuron (-like) cells in peripheral organs by cell markers in rats. Adult male Sprague-Dawley rats were anaesthetized. Their organs including brain, heart, lung, liver, kidney, stomach, duodenum, and ileum were harvested. The mRNA and protein in these organs were extracted. RNA sequencing (RNA-Seq) was carried out, and NeuN, a “specific” marker for neuronal soma, was assayed with Western blotting. The sections of the aforementioned organs were obtained after a routine fixation (4% methanal)-dehydration (ethanol)-embedding (paraffin) process. NeuN in the sections and seven non-neuronal cell lines was analyzed by immunofluorescence (IF) or immunohistochemistry (IHC). Neuronal markers, such as Eno2, NeuN (Rbfox3), choline acetyltransferase (Chat), as well as tyrosine hydroxylase (Th), and neuronal-glial markers, e.g., glial fibrillary acidic protein (Gfap), S100b, 2′, 3′-cyclic nucleotide 3′-phosphodiesterase (Cnp), and other related markers, were positively expressed in all the organs at mRNA level. NeuN was further analyzed by Western blotting. The IF and IHC assays showed that NeuN-positive cells were distributed in all the peripheral tissues (mainly peri-nuclear NeuN-positive cells) though with different patterns from that in brain (nuclear NeuN-positive cells), and a NeuN-negative tissue could not be found. Especially, NeuN and Myl3 co-expressed in the cytoplasm of myocardial cells, suggesting that NeuN could possess other functions than neuronal differentiation. Also, the protein was positively expressed in seven non-neuronal cell lines. Our findings suggested that NeuN-positive cells exist widely, and without identification of its distribution pattern, the specificity of NeuN for neurons could be limited.
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Affiliation(s)
- Yun Yu
- Department of Pharmacology, School of Basic Medicine, Kunming Medical University, Kunming, Yunnan, China
| | - Meiyu Wu
- Yunnan Provincial Key Laboratory of Molecular Biology for Sinomedicine, Faculty of Basic Medicine, Yunnan University of Traditional Chinese Medicine, Kunming, Yunnan, China
| | - Nan Zhang
- Department of Pharmacology, School of Basic Medicine, Kunming Medical University, Kunming, Yunnan, China
| | - Hua Yin
- Yunnan Provincial Key Laboratory of Molecular Biology for Sinomedicine, Faculty of Basic Medicine, Yunnan University of Traditional Chinese Medicine, Kunming, Yunnan, China
| | - Bin Shu
- Jiangsu Center for Safety Evaluation of Drugs, Jiangsu Provincial Institute of Materia Medica, Nanjing Tech University, Nanjing, Jiangsu, China
| | - Weigang Duan
- Yunnan Provincial Key Laboratory of Molecular Biology for Sinomedicine, Faculty of Basic Medicine, Yunnan University of Traditional Chinese Medicine, Kunming, Yunnan, China
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16
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Abstract
PURPOSE OF REVIEW Being a disease with heterogeneous presentations and unclear consensus on its diagnostic criteria, it is difficult to differentiate vascular parkinsonism (VaP) from other neurodegenerative parkinsonism variants. Ongoing research on structural and functional neuroimaging targeting dopaminergic pathway provides us more insight into the pathophysiology of VaP to improve diagnostic accuracy. The aim of this article is to review how the emerging imaging modalities help the diagnostic process and treatment decision in VaP. RECENT FINDINGS Dopamine transporter imaging is a promising tool in differentiating presynaptic parkinsonism and VaP. It also predicts the levodopa responders in VaP. Advanced MRI techniques including volumetry, diffusion tensor imaging and sequences visualising substantia nigra are under development, and they are complementary to each other in detecting structural and functional changes in VaP, which is crucial to ensure the quality of future therapeutic trials for VaP. Dopamine transporter imaging is recommended to patients with suspected VaP. Multimodal MRI in VaP would be an important area to be investigated in the near future.
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Affiliation(s)
- Karen K Y Ma
- Division of Neurology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
- Margaret K.L. Cheung Research Centre for Management of Parkinsonism, Gerald Choa Neuroscience Centre, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Shi Lin
- Margaret K.L. Cheung Research Centre for Management of Parkinsonism, Gerald Choa Neuroscience Centre, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Imaging & Interventional Radiology, Prince of Wales Hospital, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
- BrainNow Research Institute, Guangdong Province, Shenzhen, China
| | - Vincent C T Mok
- Division of Neurology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
- Margaret K.L. Cheung Research Centre for Management of Parkinsonism, Gerald Choa Neuroscience Centre, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
- BrainNow Research Institute, Guangdong Province, Shenzhen, China.
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17
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Pattern of tyrosine hydroxylase expression during aging of mesolimbic pathway of the rat. J Chem Neuroanat 2018; 92:83-91. [DOI: 10.1016/j.jchemneu.2018.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/24/2018] [Accepted: 05/25/2018] [Indexed: 12/13/2022]
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18
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Ribeiro MJ, Castelo-Branco M. Age-related differences in event-related potentials and pupillary responses in cued reaction time tasks. Neurobiol Aging 2018; 73:177-189. [PMID: 30366291 DOI: 10.1016/j.neurobiolaging.2018.09.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 09/18/2018] [Accepted: 09/22/2018] [Indexed: 10/28/2022]
Abstract
Deficits in the noradrenergic system are associated with age-related cognitive decline, yet how healthy aging influences the functional properties of this arousal system is still poorly understood. We addressed this question in humans using pupillometry, a well-established indicator of activity levels in the locus coeruleus (LC), the main noradrenergic center in the brain. We recorded the pupillogram and the electroencephalogram of 36 young and 39 older adults, while they were engaged in cued reaction time tasks known to elicit LC responses in monkeys. Event-related potentials (ERPs) revealed significant group differences. Older adults showed higher cortical activation during preparatory processes reflected in enhanced cue-evoked frontocentral ERPs and reduced parietal ERPs at the time of the motor response. In contrast, the amplitude of the task-related pupillary responses did not show a significant group effect. Our findings suggest that aging-related changes in cortical processing during motor preparation and execution, as documented by electroencephalogram, are not accompanied by changes in the amplitude of activation of the LC, as documented by pupillography.
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Affiliation(s)
- Maria J Ribeiro
- CIBIT, Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Coimbra, Portugal; Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
| | - Miguel Castelo-Branco
- CIBIT, Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Coimbra, Portugal; Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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19
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Prenatal exposure to oxidative phosphorylation xenobiotics and late-onset Parkinson disease. Ageing Res Rev 2018; 45:24-32. [PMID: 29689408 DOI: 10.1016/j.arr.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 12/21/2022]
Abstract
Late-onset Parkinson disease is a multifactorial and multietiological disorder, age being one of the factors implicated. Genetic and/or environmental factors, such as pesticides, can also be involved. Up to 80% of dopaminergic neurons of the substantia nigra are lost before motor features of the disorder begin to appear. In humans, these neurons are only formed a few weeks after fertilization. Therefore, prenatal exposure to pesticides or industrial chemicals during crucial steps of brain development might also alter their proliferation and differentiation. Oxidative phosphorylation is one of the metabolic pathways sensitive to environmental toxicants and it is crucial for neuronal differentiation. Many inhibitors of this biochemical pathway, frequently found as persistent organic pollutants, affect dopaminergic neurogenesis, promote the degeneration of these neurons and increase the risk of suffering late-onset Parkinson disease. Here, we discuss how an early, prenatal, exposure to these oxidative phosphorylation xenobiotics might trigger a late-onset, old age, Parkinson disease.
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20
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Sulzer D, Cassidy C, Horga G, Kang UJ, Fahn S, Casella L, Pezzoli G, Langley J, Hu XP, Zucca FA, Isaias IU, Zecca L. Neuromelanin detection by magnetic resonance imaging (MRI) and its promise as a biomarker for Parkinson's disease. NPJ PARKINSONS DISEASE 2018; 4:11. [PMID: 29644335 PMCID: PMC5893576 DOI: 10.1038/s41531-018-0047-3] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 11/10/2022]
Abstract
The diagnosis of Parkinson’s disease (PD) occurs after pathogenesis is advanced and many substantia nigra (SN) dopamine neurons have already died. Now that therapies to block this neuronal loss are under development, it is imperative that the disease be diagnosed at earlier stages and that the response to therapies is monitored. Recent studies suggest this can be accomplished by magnetic resonance imaging (MRI) detection of neuromelanin (NM), the characteristic pigment of SN dopaminergic, and locus coeruleus (LC) noradrenergic neurons. NM is an autophagic product synthesized via oxidation of catecholamines and subsequent reactions, and in the SN and LC it increases linearly during normal aging. In PD, however, the pigment is lost when SN and LC neurons die. As shown nearly 25 years ago by Zecca and colleagues, NM’s avid binding of iron provides a paramagnetic source to enable electron and nuclear magnetic resonance detection, and thus a means for safe and noninvasive measure in living human brain. Recent technical improvements now provide a means for MRI to differentiate between PD patients and age-matched healthy controls, and should be able to identify changes in SN NM with age in individuals. We discuss how MRI detects NM and how this approach might be improved. We suggest that MRI of NM can be used to confirm PD diagnosis and monitor disease progression. We recommend that for subjects at risk for PD, and perhaps generally for older people, that MRI sequences performed at regular intervals can provide a pre-clinical means to detect presymptomatic PD.
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Affiliation(s)
- David Sulzer
- 1Department of Psychiatry, Columbia University Medical Center , New York State Psychiatric Institute, New York, NY USA.,2Department of Neurology, Columbia University Medical Center, New York, NY USA.,3Department of Pharmacology, Columbia University Medical Center, New York, NY USA
| | - Clifford Cassidy
- 4The Royal's Institute of Mental Health Research, Affiliated with the University of Ottawa, Ottawa, ON Canada
| | - Guillermo Horga
- 1Department of Psychiatry, Columbia University Medical Center , New York State Psychiatric Institute, New York, NY USA
| | - Un Jung Kang
- 2Department of Neurology, Columbia University Medical Center, New York, NY USA
| | - Stanley Fahn
- 2Department of Neurology, Columbia University Medical Center, New York, NY USA
| | - Luigi Casella
- 5Department of Chemistry, University of Pavia, Pavia, Italy
| | - Gianni Pezzoli
- Parkinson Institute, ASST "Gaetano Pini-CTO", Milan, Italy
| | - Jason Langley
- 7Center for Advanced NeuroImaging, University of California Riverside, Riverside, CA USA
| | - Xiaoping P Hu
- 8Department of Bioengineering, University of California Riverside, Riverside, CA USA
| | - Fabio A Zucca
- 9Institute of Biomedical Technologies, National Research Council of Italy, Milan, Italy
| | - Ioannis U Isaias
- Department of Neurology, University Hospital and Julius-Maximillian-University, Wuerzburg, Germany
| | - Luigi Zecca
- 9Institute of Biomedical Technologies, National Research Council of Italy, Milan, Italy
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21
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Altered function of neuronal L-type calcium channels in ageing and neuroinflammation: Implications in age-related synaptic dysfunction and cognitive decline. Ageing Res Rev 2018; 42:86-99. [PMID: 29339150 DOI: 10.1016/j.arr.2018.01.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 12/29/2022]
Abstract
The rapid developments in science have led to an increase in human life expectancy and thus, ageing and age-related disorders/diseases have become one of the greatest concerns in the 21st century. Cognitive abilities tend to decline as we get older. This age-related cognitive decline is mainly attributed to aberrant changes in synaptic plasticity and neuronal connections. Recent studies show that alterations in Ca2+ homeostasis underlie the increased vulnerability of neurons to age-related processes like cognitive decline and synaptic dysfunctions. Dysregulation of Ca2+ can lead to dramatic changes in neuronal functions. We discuss in this review, the recent advances on the potential role of dysregulated Ca2+ homeostasis through altered function of L-type voltage gated Ca2+ channels (LTCC) in ageing, with an emphasis on cognitive decline. This review therefore focuses on age-related changes mainly in the hippocampus, and with mention of other brain areas, that are important for learning and memory. This review also highlights age-related memory deficits via synaptic alterations and neuroinflammation. An understanding of these mechanisms will help us formulate strategies to reverse or ameliorate age-related disorders like cognitive decline.
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22
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Garrido-Gil P, Dominguez-Meijide A, Moratalla R, Guerra MJ, Labandeira-Garcia JL. Aging-related dysregulation in enteric dopamine and angiotensin system interactions: implications for gastrointestinal dysfunction in the elderly. Oncotarget 2018. [PMID: 29541380 PMCID: PMC5834264 DOI: 10.18632/oncotarget.24330] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Gastrointestinal dysfunction is a common problem in the elderly. Aging-related changes in interactions between local dopaminergic and renin-angiotensin systems (RAS) have been observed in the brain, renal and vascular tissues. However, it is not known if these interactions also occur in the gut, and are dysregulated with aging. We showed a mutual regulation between the colonic dopaminergic system and RAS using young and aged mice deficient for major angiotensin and dopamine receptors. Aged rats showed a marked decrease in colonic dopamine D2 receptor expression, together with an increase in angiotensin type 1 (AT1) receptor expression, a decrease in angiotensin type 2 (AT2) receptor expression (i.e. an increase in the RAS pro-inflammatory arm activity), and increased levels of inflammatory and oxidative markers. Aged rats also showed increased levels of colonic dopamine and noradrenalin, and a marked decrease in acetylcholine and serotonin levels. The present observations contribute to explain an aging-related pro-inflammatory state and dysregulation in gastrointestinal function, which may be counteracted by treatment of aged animals with the AT1 receptor blocker candesartan.
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Affiliation(s)
- Pablo Garrido-Gil
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Research Center for Molecular Medicine and Chronic Diseases, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Centre on Neurodegenerative Diseases, Madrid, Spain
| | - Antonio Dominguez-Meijide
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Research Center for Molecular Medicine and Chronic Diseases, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Centre on Neurodegenerative Diseases, Madrid, Spain
| | - Rosario Moratalla
- Networking Research Centre on Neurodegenerative Diseases, Madrid, Spain.,Instituto Cajal, Madrid, Spain
| | - Maria J Guerra
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Research Center for Molecular Medicine and Chronic Diseases, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Centre on Neurodegenerative Diseases, Madrid, Spain
| | - Jose L Labandeira-Garcia
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Research Center for Molecular Medicine and Chronic Diseases, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Centre on Neurodegenerative Diseases, Madrid, Spain
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23
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Betts MJ, Cardenas-Blanco A, Kanowski M, Jessen F, Düzel E. In vivo MRI assessment of the human locus coeruleus along its rostrocaudal extent in young and older adults. Neuroimage 2017; 163:150-159. [PMID: 28943414 DOI: 10.1016/j.neuroimage.2017.09.042] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 12/24/2022] Open
Abstract
The locus coeruleus (LC), a major origin of noradrenergic projections in the central nervous system (CNS), may serve a critical role in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). As such, there is considerable interest to develop magnetic resonance imaging (MRI) techniques to assess the integrity of the LC in vivo. The high neuromelanin content of the LC serves as an endogenous contrast for MRI but existing protocols suffer from low spatial resolution along the rostrocaudal axis of the LC rendering it difficult to differentiate its integrity in caudal and rostral portions. This study presents a novel approach to investigate the human LC in vivo using T1-weighted Fast Low Angle Shot (FLASH) MRI at 3 T (T). Using high-resolution isotropic imaging to minimise the effect of low spatial resolution in the slice direction, this study aimed to characterise the rostrocaudal distribution of LC signal intensity attributed to neuromelanin from 25 young (22-30) and 57 older (61-80) adults. We found a significant age-related increase in maximum but not median signal intensity, indicating age-related differences were not homogenous. Instead, they were confined to the rostral third of the LC with relative sparing of the caudal portion. The findings presented demonstrate in vivo T1-weighted FLASH imaging may be used to characterise signal intensity changes across the entire rostrocaudal length of the LC (a corresponding standardised LC map is available for download), which may help to identify how the human LC is differentially affected in aging and neurodegenerative disease.
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Affiliation(s)
- Matthew J Betts
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.
| | - Arturo Cardenas-Blanco
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Martin Kanowski
- Department of Neurology, University Hospital of Magdeburg, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Frank Jessen
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; Department of Psychiatry, University of Cologne, Cologne, Germany
| | - Emrah Düzel
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany; Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, UK
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24
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von Bartheld CS. Myths and truths about the cellular composition of the human brain: A review of influential concepts. J Chem Neuroanat 2017; 93:2-15. [PMID: 28873338 DOI: 10.1016/j.jchemneu.2017.08.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 11/17/2022]
Abstract
Over the last 50 years, quantitative methodology has made important contributions to our understanding of the cellular composition of the human brain. Not all of the concepts that emerged from quantitative studies have turned out to be true. Here, I examine the history and current status of some of the most influential notions. This includes claims of how many cells compose the human brain, and how different cell types contribute and in what ratios. Additional concepts entail whether we lose significant numbers of neurons with normal aging, whether chronic alcohol abuse contributes to cortical neuron loss, whether there are significant differences in the quantitative composition of cerebral cortex between male and female brains, whether superior intelligence in humans correlates with larger numbers of brain cells, and whether there are secular (generational) changes in neuron number. Do changes in cell number or changes in ratios of cell types accompany certain diseases, and should all counting methods, even the theoretically unbiased ones, be validated and calibrated? I here examine the origin and the current status of major influential concepts, and I review the evidence and arguments that have led to either confirmation or refutation of such concepts. I discuss the circumstances, assumptions and mindsets that perpetuated erroneous views, and the types of technological advances that have, in some cases, challenged longstanding ideas. I will acknowledge the roles of key proponents of influential concepts in the sometimes convoluted path towards recognition of the true cellular composition of the human brain.
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Affiliation(s)
- Christopher S von Bartheld
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Mailstop 352, Reno, NV 89557, USA.
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25
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Fabbri M, Reimão S, Carvalho M, Nunes RG, Abreu D, Guedes LC, Bouça R, Lobo PP, Godinho C, Coelho M, Gonçalves NC, Rosa MM, Antonini A, Ferreira JJ. Substantia Nigra Neuromelanin as an Imaging Biomarker of Disease Progression in Parkinson’s Disease. JOURNAL OF PARKINSONS DISEASE 2017; 7:491-501. [DOI: 10.3233/jpd-171135] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Margherita Fabbri
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Sofia Reimão
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
- Department of Neurological Imaging, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - Miguel Carvalho
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, University of Lisbon, Lisbon, Portugal
| | - Rita G. Nunes
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, University of Lisbon, Lisbon, Portugal
- Department of Bioengineering and Institute for Systems and Robotics (LARSyS), Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Daisy Abreu
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Leonor Correia Guedes
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
- Department of Neurosciences, Hospital Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - Raquel Bouça
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Patricia P. Lobo
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Catarina Godinho
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
- Center for Interdisciplinary Research Egas Moniz(CiiEM), Instituto Superior de Ciências da Saúde EgasMoniz, Monte de Caparica, Portugal
- CNS – Campus Neurológico Sénior, Torres Vedras, Portugal
| | - Miguel Coelho
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
- Department of Neurosciences, Hospital Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - Nilza C. Gonçalves
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Mario Miguel Rosa
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
- Department of Neurosciences, Hospital Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - Angelo Antonini
- Fondazione Ospedale San Camillo”-I.R.C.C.S., Parkinson and Movement Disorders Unit, Venice, Italy
| | - Joaquim J. Ferreira
- Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
- CNS – Campus Neurológico Sénior, Torres Vedras, Portugal
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
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26
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Labandeira-Garcia JL, Rodríguez-Perez AI, Garrido-Gil P, Rodriguez-Pallares J, Lanciego JL, Guerra MJ. Brain Renin-Angiotensin System and Microglial Polarization: Implications for Aging and Neurodegeneration. Front Aging Neurosci 2017; 9:129. [PMID: 28515690 PMCID: PMC5413566 DOI: 10.3389/fnagi.2017.00129] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/18/2017] [Indexed: 12/12/2022] Open
Abstract
Microglia can transform into proinflammatory/classically activated (M1) or anti-inflammatory/alternatively activated (M2) phenotypes following environmental signals related to physiological conditions or brain lesions. An adequate transition from the M1 (proinflammatory) to M2 (immunoregulatory) phenotype is necessary to counteract brain damage. Several factors involved in microglial polarization have already been identified. However, the effects of the brain renin-angiotensin system (RAS) on microglial polarization are less known. It is well known that there is a “classical” circulating RAS; however, a second RAS (local or tissue RAS) has been observed in many tissues, including brain. The locally formed angiotensin is involved in local pathological changes of these tissues and modulates immune cells, which are equipped with all the components of the RAS. There are also recent data showing that brain RAS plays a major role in microglial polarization. Level of microglial NADPH-oxidase (Nox) activation is a major regulator of the shift between M1/proinflammatory and M2/immunoregulatory microglial phenotypes so that Nox activation promotes the proinflammatory and inhibits the immunoregulatory phenotype. Angiotensin II (Ang II), via its type 1 receptor (AT1), is a major activator of the NADPH-oxidase complex, leading to pro-oxidative and pro-inflammatory effects. However, these effects are counteracted by a RAS opposite arm constituted by Angiotensin II/AT2 receptor signaling and Angiotensin 1–7/Mas receptor (MasR) signaling. In addition, activation of prorenin-renin receptors may contribute to activation of the proinflammatory phenotype. Aged brains showed upregulation of AT1 and downregulation of AT2 receptor expression, which may contribute to a pro-oxidative pro-inflammatory state and the increase in neuron vulnerability. Several recent studies have shown interactions between the brain RAS and different factors involved in microglial polarization, such as estrogens, Rho kinase (ROCK), insulin-like growth factor-1 (IGF-1), tumor necrosis factor α (TNF)-α, iron, peroxisome proliferator-activated receptor gamma, and toll-like receptors (TLRs). Metabolic reprogramming has recently been involved in the regulation of the neuroinflammatory response. Interestingly, we have recently observed a mitochondrial RAS, which is altered in aged brains. In conclusion, dysregulation of brain RAS plays a major role in aging-related changes and neurodegeneration by exacerbation of oxidative
stress (OS) and neuroinflammation, which may be attenuated by pharmacological manipulation of RAS components.
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Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Ana I Rodríguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Pablo Garrido-Gil
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Jannette Rodriguez-Pallares
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Jose L Lanciego
- Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain.,Neurosciences Division, Center for Applied Medical Research (CIMA), University of NavarraPamplona, Spain
| | - Maria J Guerra
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
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27
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Feinstein DL, Kalinin S, Braun D. Causes, consequences, and cures for neuroinflammation mediated via the locus coeruleus: noradrenergic signaling system. J Neurochem 2016; 139 Suppl 2:154-178. [PMID: 26968403 DOI: 10.1111/jnc.13447] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 12/31/2022]
Abstract
Aside from its roles in as a classical neurotransmitter involved in regulation of behavior, noradrenaline (NA) has other functions in the CNS. This includes restricting the development of neuroinflammatory activation, providing neurotrophic support to neurons, and providing neuroprotection against oxidative stress. In recent years, it has become evident that disruption of physiological NA levels or signaling is a contributing factor to a variety of neurological diseases and conditions including Alzheimer's disease (AD) and Multiple Sclerosis. The basis for dysregulation in these diseases is, in many cases, due to damage occurring to noradrenergic neurons present in the locus coeruleus (LC), the major source of NA in the CNS. LC damage is present in AD, multiple sclerosis, and a large number of other diseases and conditions. Studies using animal models have shown that experimentally induced lesion of LC neurons exacerbates neuropathology while treatments to compensate for NA depletion, or to reduce LC neuronal damage, provide benefit. In this review, we will summarize the anti-inflammatory and neuroprotective actions of NA, summarize examples of how LC damage worsens disease, and discuss several approaches taken to treat or prevent reductions in NA levels and LC neuronal damage. Further understanding of these events will be of value for the development of treatments for AD, multiple sclerosis, and other diseases and conditions having a neuroinflammatory component. The classical neurotransmitter noradrenaline (NA) has critical roles in modulating behaviors including those involved in sleep, anxiety, and depression. However, NA can also elicit anti-inflammatory responses in glial cells, can increase neuronal viability by inducing neurotrophic factor expression, and can reduce neuronal damage due to oxidative stress by scavenging free radicals. NA is primarily produced by tyrosine hydroxylase (TH) expressing neurons in the locus coeruleus (LC), a relatively small brainstem nucleus near the IVth ventricle which sends projections throughout the brain and spinal cord. It has been known for close to 50 years that LC neurons are lost during normal aging, and that loss is exacerbated in neurological diseases including Parkinson's disease and Alzheimer's disease. LC neuronal damage and glial activation has now been documented in a variety of other neurological conditions and diseases, however, the causes of LC damage and cell loss remain largely unknown. A number of approaches have been developed to address the loss of NA and increased inflammation associated with LC damage, and several methods are being explored to directly minimize the extent of LC neuronal cell loss or function. In this review, we will summarize some of the consequences of LC loss, consider several factors that likely contribute to that loss, and discuss various ways that have been used to increase NA or to reduce LC damage. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Douglas L Feinstein
- Department of Anesthesiology, University of Illinois, Chicago, IL, USA. .,Jesse Brown VA Medical Center, Chicago, IL, USA.
| | - Sergey Kalinin
- Department of Anesthesiology, University of Illinois, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
| | - David Braun
- Department of Anesthesiology, University of Illinois, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
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28
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Mather M, Harley CW. The Locus Coeruleus: Essential for Maintaining Cognitive Function and the Aging Brain. Trends Cogn Sci 2016; 20:214-226. [PMID: 26895736 PMCID: PMC4761411 DOI: 10.1016/j.tics.2016.01.001] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/04/2016] [Accepted: 01/05/2016] [Indexed: 12/15/2022]
Abstract
Research on cognitive aging has focused on how decline in various cortical and hippocampal regions influence cognition. However, brainstem regions play essential modulatory roles, and new evidence suggests that, among these, the integrity of the locus coeruleus (LC)-norepinephrine (NE) system plays a key role in determining late-life cognitive abilities. The LC is especially vulnerable to toxins and infection and is often the first place Alzheimer's-related pathology appears, with most people showing at least some tau pathology by their mid-20s. On the other hand, NE released from the LC during arousing, mentally challenging, or novel situations helps to protect neurons from damage, which may help to explain how education and engaging careers prevent cognitive decline in later years.
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Affiliation(s)
- Mara Mather
- Davis School of Gerontology and Department of Psychology, University of Southern California, Los Angeles, CA, USA.
| | - Carolyn W Harley
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada.
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29
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Arnold JC, Salvatore MF. Exercise-Mediated Increase in Nigral Tyrosine Hydroxylase Is Accompanied by Increased Nigral GFR-α1 and EAAC1 Expression in Aging Rats. ACS Chem Neurosci 2016; 7:227-39. [PMID: 26599339 PMCID: PMC4926611 DOI: 10.1021/acschemneuro.5b00282] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Exercise may alleviate locomotor impairment in Parkinson's disease (PD) or aging. Identifying molecular responses immediately engaged by exercise in the nigrostriatal pathway and allied tissue may reveal critical targets associated with its long-term benefits. In aging, there is loss of tyrosine hydroxylase (TH) and the glial cell line-derived neurotrophic factor (GDNF) receptor, GFR-α1, in the substantia nigra (SN). Exercise can increase GDNF expression, but its effect on GFR-α1 expression is unknown. Infusion of GDNF into striatum or GFR-α1 in SN, respectively, can increase locomotor activity and TH function in SN but not striatum in aged rats. GDNF may also increase glutamate transporter expression, which attenuates TH loss in PD models. We utilized a footshock-free treadmill exercise regimen to determine the immediate impact of short-term exercise on GFR-α1 expression, dopamine regulation, glutamate transporter expression, and glutamate uptake in 18 month old male Brown-Norway/Fischer 344 F1 hybrid rats. GFR-α1 and TH expression significantly increased in SN but not striatum. This exercise regimen did not affect glutamate uptake or glutamate transporter expression in striatum. However, EAAC1 expression increased in SN. These results indicate that nigral GFR-α1 and EAAC1 expression increased in conjunction with increased nigral TH expression following short-term exercise.
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Affiliation(s)
- Jennifer C. Arnold
- Department of Pharmacology, Toxicology & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, United States
| | - Michael F. Salvatore
- Department of Pharmacology, Toxicology & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, United States
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
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30
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Di Lorenzo Alho AT, Suemoto CK, Polichiso L, Tampellini E, de Oliveira KC, Molina M, Santos GAB, Nascimento C, Leite REP, de Lucena Ferreti-Rebustini RE, da Silva AV, Nitrini R, Pasqualucci CA, Jacob-Filho W, Heinsen H, Grinberg LT. Three-dimensional and stereological characterization of the human substantia nigra during aging. Brain Struct Funct 2015; 221:3393-403. [PMID: 26386691 DOI: 10.1007/s00429-015-1108-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/05/2015] [Indexed: 11/24/2022]
Abstract
The human brain undergoes non-uniform changes during aging. The substantia nigra (SN), the source of major dopaminergic pathways in the brain, is particularly vulnerable to changes in the progression of several age-related neurodegenerative diseases. To establish normative data for high-resolution imaging, and to further clinical and anatomical studies we analyzed SNs from 15 subjects aged 50-91 cognitively normal human subjects without signs of parkinsonism. Complete brains or brainstems with substantia nigra were formalin-fixed, celloidin-mounted, serially cut and Nissl-stained. The shapes of all SNs investigated were reconstructed using fast, high-resolution computer-assisted 3D reconstruction software. We found a negative correlation between age and SN volume (p = 0.04, rho = -0.53), with great variability in neuronal numbers and density across participants. The 3D reconstructions revealed SN inter- and intra-individual variability. Furthermore, we observed that human SN is a neuronal reticulum, rather than a group of isolated neuronal islands. Caution is required when using SN volume as a surrogate for SN status in individual subjects. The use of multimodal sequences including those for fiber tracts may enhance the value of imaging as a diagnostic tool to assess SN in vivo. Further studies with a larger sample size are needed for understanding the structure-function interaction of human SN.
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Affiliation(s)
- Ana Tereza Di Lorenzo Alho
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Labor für Morphologische Hirnforschung der Klinik und Poliklinik für Psychiatrie und Psychotherapie, Institut Rechtsmedizin, Universitätsklinikum Würzburg, Würzburg, Germany.,Instituto do Cérebro, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Claudia Kimie Suemoto
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Discipline of Geriatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Lívia Polichiso
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil
| | - Edilaine Tampellini
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil
| | - Kátia Cristina de Oliveira
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Labor für Morphologische Hirnforschung der Klinik und Poliklinik für Psychiatrie und Psychotherapie, Institut Rechtsmedizin, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Mariana Molina
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil
| | - Glaucia Aparecida Bento Santos
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Instituto do Cérebro, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Camila Nascimento
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil
| | - Renata Elaine Paraizo Leite
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Discipline of Geriatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Renata Eloah de Lucena Ferreti-Rebustini
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Discipline of Geriatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Alexandre Valotta da Silva
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Instituto do Cérebro, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Ricardo Nitrini
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Department of Neurology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Carlos Augusto Pasqualucci
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, São Paulo, Brazil
| | - Wilson Jacob-Filho
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil.,Discipline of Geriatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Helmut Heinsen
- Labor für Morphologische Hirnforschung der Klinik und Poliklinik für Psychiatrie und Psychotherapie, Institut Rechtsmedizin, Universitätsklinikum Würzburg, Würzburg, Germany.,Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, São Paulo, Brazil
| | - Lea Tenenholz Grinberg
- Grupo de Estudos em Envelhecimento Cerebral e LIM 22, Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 sala 1353, São Paulo, CEP 01246-903, Brazil. .,Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA. .,Department of Pathology, Faculdade de Medicina da Universidade de Sao Paulo, São Paulo, Brazil.
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31
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Aging causes morphological alterations in astrocytes and microglia in human substantia nigra pars compacta. Neurobiol Aging 2015; 36:3321-3333. [PMID: 26433682 DOI: 10.1016/j.neurobiolaging.2015.08.024] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/30/2015] [Accepted: 08/25/2015] [Indexed: 12/20/2022]
Abstract
Age being a risk factor for Parkinson's disease, assessment of age-related changes in the human substantia nigra may elucidate its pathogenesis. Increase in Marinesco bodies, α-synuclein, free radicals and so forth in the aging nigral neurons are clear indicators of neurodegeneration. Here, we report the glial responses in aging human nigra. The glial numbers were determined on Nissl-stained sections. The expression of glial fibrillary acidic protein, S100β, 2', 3'-cyclic nucleotide 3' phosphodiesterase, and Iba1 was assessed on cryosections of autopsied midbrains by immunohistochemistry and densitometry. The glial counts showed a biphasic increase, of which, the first prominent phase from fetal age to birth could be physiological gliogenesis whereas the second one after middle age may reflect mild age-related gliosis. Astrocytic morphology was altered, but glial fibrillary acidic protein expression increased only mildly. Presence of type-4 microglia suggests possibility of neuroinflammation. Mild reduction in 2', 3'-cyclic nucleotide 3' phosphodiesterase-labeled area denotes subtle demyelination. Stable age-related S100β expression indicates absence of calcium overload. Against the expected prominent gliosis, subtle age-related morphological alterations in human nigral glia attribute them a participatory role in aging.
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Parkinson GM, Dayas CV, Smith DW. Age-related gene expression changes in substantia nigra dopamine neurons of the rat. Mech Ageing Dev 2015; 149:41-9. [PMID: 26065381 DOI: 10.1016/j.mad.2015.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 06/01/2015] [Accepted: 06/02/2015] [Indexed: 02/01/2023]
Abstract
Ageing affects most, if not all, functional systems in the body. For example, the somatic motor nervous system, responsible for initiating and regulating motor output to skeletal musculature, is vulnerable to ageing. The nigrostriatal dopamine pathway is one component of this system, with deficits in dopamine signalling contributing to major motor dysfunction, as exemplified in Parkinson's disease (PD). However, while the dopamine deficit in PD is due to degeneration of substantia nigra (SN) dopamine (DA) neurons, it is unclear whether there is sufficient loss of SN DA neurons with ageing to explain observed motor impairments. Instead, evidence suggests that age-related loss of DA neuron function may be more important than frank cell loss. To further elucidate the mechanisms of functional decline, we have investigated age-related changes in gene expression specifically in laser microdissected SN DA neurons. There were significant age-related changes in the expression of genes associated with neurotrophic factor signalling and the regulation of tyrosine hydroxylase activity. Furthermore, reduced expression of the DA neuron-associated transcription factor, Nurr1, may contribute to these changes. Together, these results suggest that altered neurotrophic signalling and tyrosine hydroxylase activity may contribute to altered DA neuron signalling and motor nervous system regulation in ageing.
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Affiliation(s)
- Gemma M Parkinson
- Preclinical Neurobiology Research Program, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia; Centre for Translational Neuroscience and Mental Health Research, University of Newcastle, Callaghan, NSW 2308, Australia; Hunter Medical Research Institute, 1/Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia.
| | - Christopher V Dayas
- Preclinical Neurobiology Research Program, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia; Centre for Translational Neuroscience and Mental Health Research, University of Newcastle, Callaghan, NSW 2308, Australia; Hunter Medical Research Institute, 1/Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia.
| | - Doug W Smith
- Preclinical Neurobiology Research Program, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia; Centre for Translational Neuroscience and Mental Health Research, University of Newcastle, Callaghan, NSW 2308, Australia; Hunter Medical Research Institute, 1/Kookaburra Circuit, New Lambton Heights, NSW 2305, Australia.
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Decreased expression of organic cation transporters, Oct1 and Oct2, in brain microvessels and its implication to MPTP-induced dopaminergic toxicity in aged mice. J Cereb Blood Flow Metab 2015; 35:37-47. [PMID: 25248837 PMCID: PMC4294392 DOI: 10.1038/jcbfm.2014.162] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 08/25/2014] [Accepted: 08/26/2014] [Indexed: 12/15/2022]
Abstract
This study was to investigate the influence of age on the expression of organic cation transporters (OCTs) that belong to the SLC22 family in brain microvessels (BMVs) and its implications for 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic toxicity in mice. Here, we showed that Oct1 and Oct2, but not Oct3, mRNAs were detected and enriched (compared with cerebral cortex) in BMVs of C57BL/6 (B6) mice using reverse transcription-quantitative PCR (RT-qPCR), and immunofluorescence analysis further revealed that Oct1 and Oct2 proteins were colocalized with endothelial markers. Both the mRNA and protein levels of Oct1 and Oct2 were reduced in aged mice. After an intraperitoneal administration of MPTP, brain extracellular levels of MPTP and 1-methyl-4-phenyl-pyridinium (MPP(+)) were much lower in aged mice and in Oct1/2(-/-) mice compared with younger mice and wild-type control mice, respectively. Knockout of Oct1/Oct2 protected Oct1/2(-/-) mice from MPTP-induced neurotoxicity, whereas the loss of tyrosine hydroxylase (TH)-positive neurons was slightly greater in aged than in younger mice. However, intrastriatal infusion of low-dose MPTP caused more severe dopaminergic toxicity in the substantia nigra of both aged mice and Oct1/2(-/-) mice. These findings show that age-dependent downregulation or knockout of Oct1/Oct2 in BMVs may reduce the transport of MPTP, which, in part, affects its dopaminergic toxicity.
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Mapping dopaminergic deficiencies in the substantia nigra/ventral tegmental area in schizophrenia. Brain Struct Funct 2014; 221:185-201. [PMID: 25269834 DOI: 10.1007/s00429-014-0901-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/23/2014] [Indexed: 01/07/2023]
Abstract
Previous work from our laboratory showed deficits in tyrosine hydroxylase protein expression within the substantia nigra/ventral tegmental area (SN/VTA) in schizophrenia. However, little is known about the nature and specific location of these deficits within the SN/VTA. The present study had two aims: (1) test if tyrosine hydroxylase deficits could be explained as the result of neuronal loss; (2) assess if deficits in tyrosine hydroxylase are sub-region specific within the SN/VTA, and thus, could affect specific dopaminergic pathways. To achieve these objectives: (1) we obtained estimates of the number of dopaminergic neurons, total number of neurons, and their ratio in matched SN/VTA schizophrenia and control samples; (2) we performed a qualitative assessment in SN/VTA schizophrenia and control matched samples that were processed simultaneously for tyrosine hydroxylase immunohistochemistry. We did not find any significant differences in the total number of neurons, dopaminergic neurons, or their ratio. Our qualitative study of TH expression showed a conspicuous decrease in labeling of neuronal processes and cell bodies within the SN/VTA, which was sub-region specific. Dorsal diencephalic dopaminergic populations of the SN/VTA presented the most conspicuous decrease in TH labeling. These data support the existence of pathway-specific dopaminergic deficits that would affect the dopamine input to the cortex without significant neuronal loss. Interestingly, these findings support earlier reports of decreases in tyrosine hydroxylase labeling in the target areas for this dopaminergic input in the prefrontal and entorhinal cortex. Finally, our findings support that tyrosine hydroxylase deficits could contribute to the hypodopaminergic state observed in cortical areas in schizophrenia.
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Aging decreases L-type calcium channel currents and pacemaker firing fidelity in substantia nigra dopamine neurons. J Neurosci 2014; 34:9310-8. [PMID: 25009264 DOI: 10.1523/jneurosci.4228-13.2014] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Substantia nigra dopamine neurons are involved in behavioral processes that include cognition, reward learning, and voluntary movement. Selective deterioration of these neurons is responsible for the motor deficits associated with Parkinson's disease (PD). Aging is the leading risk factor for PD, suggesting that adaptations occurring in dopamine neurons during normal aging may predispose individuals to the development of PD. Previous studies suggest that the unique set of ion conductances that drive spontaneous, rhythmic firing of action potentials could predispose substantia nigra dopamine neurons to selective neurodegeneration. Here we show, using patch-clamp electrophysiological recordings in brain slices, that substantia nigra dopamine neurons from mice 25-30 months of age (old) have comparable membrane capacitance and input resistance to neurons from mice 2-7 months of age (young). However, neurons from old mice exhibit slower firing rates, narrower spike widths, and more variable interspike intervals compared with neurons from young mice. Dopamine neurons from old mice also exhibit smaller L-type calcium channel currents, providing a plausible mechanism that likely contributes to the changes in impulse activity. Age-related decrements in the physiological function of dopamine neurons could contribute to the decrease in voluntary movement and other dopamine-mediated behaviors observed in aging populations. Furthermore, as pharmacological antagonism of L-type calcium channels has been proposed as a potential treatment for the early stages of PD, our results could point to a limited temporal window of opportunity for this therapeutic intervention.
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Labandeira-García JL, Garrido-Gil P, Rodriguez-Pallares J, Valenzuela R, Borrajo A, Rodríguez-Perez AI. Brain renin-angiotensin system and dopaminergic cell vulnerability. Front Neuroanat 2014; 8:67. [PMID: 25071471 PMCID: PMC4086395 DOI: 10.3389/fnana.2014.00067] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 06/24/2014] [Indexed: 01/11/2023] Open
Abstract
Although the renin-angiotensin system (RAS) was classically considered as a circulating system that regulates blood pressure, many tissues are now known to have a local RAS. Angiotensin, via type 1 receptors, is a major activator of the NADPH-oxidase complex, which mediates several key events in oxidative stress (OS) and inflammatory processes involved in the pathogenesis of major aging-related diseases. Several studies have demonstrated the presence of RAS components in the basal ganglia, and particularly in the nigrostriatal system. In the nigrostriatal system, RAS hyperactivation, via NADPH-oxidase complex activation, exacerbates OS and the microglial inflammatory response and contributes to progression of dopaminergic degeneration, which is inhibited by angiotensin receptor blockers and angiotensin converting enzyme (ACE) inhibitors. Several factors may induce an increase in RAS activity in the dopaminergic system. A decrease in dopaminergic activity induces compensatory upregulation of local RAS function in both dopaminergic neurons and glia. In addition to its role as an essential neurotransmitter, dopamine may also modulate microglial inflammatory responses and neuronal OS via RAS. Important counterregulatory interactions between angiotensin and dopamine have also been observed in several peripheral tissues. Neurotoxins and proinflammatory factors may also act on astrocytes to induce an increase in RAS activity, either independently of or before the loss of dopamine. Consistent with a major role of RAS in dopaminergic vulnerability, increased RAS activity has been observed in the nigra of animal models of aging, menopause and chronic cerebral hypoperfusion, which also showed higher dopaminergic vulnerability. Manipulation of the brain RAS may constitute an effective neuroprotective strategy against dopaminergic vulnerability and progression of Parkinson's disease.
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Affiliation(s)
- Jose L Labandeira-García
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Pablo Garrido-Gil
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Jannette Rodriguez-Pallares
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Rita Valenzuela
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Ana Borrajo
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Ana I Rodríguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
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Aging-related dysregulation of dopamine and angiotensin receptor interaction. Neurobiol Aging 2014; 35:1726-38. [PMID: 24529758 DOI: 10.1016/j.neurobiolaging.2014.01.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 01/10/2014] [Accepted: 01/13/2014] [Indexed: 12/22/2022]
Abstract
It is not known whether the aging-related decrease in dopaminergic function leads to the aging-related higher vulnerability of dopaminergic neurons and risk for Parkinson's disease. The renin-angiotensin system (RAS) plays a major role in the inflammatory response, neuronal oxidative stress, and dopaminergic vulnerability via type 1 (AT1) receptors. In the present study, we observed a counterregulatory interaction between dopamine and angiotensin receptors. We observed overexpression of AT1 receptors in the striatum and substantia nigra of young adult dopamine D1 and D2 receptor-deficient mice and young dopamine-depleted rats, together with compensatory overexpression of AT2 receptors or compensatory downregulation of angiotensinogen and/or angiotensin. In aged rats, we observed downregulation of dopamine and dopamine receptors and overexpression of AT1 receptors in aged rats, without compensatory changes observed in young animals. L-Dopa therapy inhibited RAS overactivity in young dopamine-depleted rats, but was ineffective in aged rats. The results suggest that dopamine may play an important role in modulating oxidative stress and inflammation in the substantia nigra and striatum via the RAS, which is impaired by aging.
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Hare DJ, Lei P, Ayton S, Roberts BR, Grimm R, George JL, Bishop DP, Beavis AD, Donovan SJ, McColl G, Volitakis I, Masters CL, Adlard PA, Cherny RA, Bush AI, Finkelstein DI, Doble PA. An iron–dopamine index predicts risk of parkinsonian neurodegeneration in the substantia nigra pars compacta. Chem Sci 2014. [DOI: 10.1039/c3sc53461h] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Imaging of iron and dopamine by laser ablation-inductively coupled plasma-mass spectrometry reveals a risk index for parkinsonian neurodegeneration
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Affiliation(s)
- Dominic J. Hare
- Elemental Bio-imaging Facility
- University of Technology
- Sydney, Australia
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
| | - Peng Lei
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Scott Ayton
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Blaine R. Roberts
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Rudolf Grimm
- Agilent Technologies
- Santa Clara, United States of America
| | - Jessica L. George
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - David P. Bishop
- Elemental Bio-imaging Facility
- University of Technology
- Sydney, Australia
| | - Alison D. Beavis
- Elemental Bio-imaging Facility
- University of Technology
- Sydney, Australia
| | - Sarah J. Donovan
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
- Deakin University
- Burwood, Australia
| | - Gawain McColl
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Irene Volitakis
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Colin L. Masters
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Paul A. Adlard
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Robert A. Cherny
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Ashley I. Bush
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - David I. Finkelstein
- The Florey Institute of Neuroscience and Mental Health
- The University of Melbourne
- Parkville, Australia
| | - Philip A. Doble
- Elemental Bio-imaging Facility
- University of Technology
- Sydney, Australia
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39
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Neuromelanin of the human substantia nigra: an update. Neurotox Res 2013; 25:13-23. [PMID: 24155156 DOI: 10.1007/s12640-013-9435-y] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 01/22/2023]
Abstract
Dopaminergic neurons of the substantia nigra selectively degenerate over the course of Parkinson's disease. These neurons are also the most heavily pigmented cells of the brain, accumulating the dark pigment neuromelanin over a lifetime. The massive presence of neuromelanin in these brain areas has long been suspected as a key factor involved in the selective vulnerability of neurons. The high concentration of neuromelanin in substantia nigra neurons seems to be linked to the presence of considerable amounts of cytosolic dopamine that have not been sequestered into synaptic vesicles. Over the past few years, studies have uncovered a dual nature of neuromelanin. Intraneuronal neuromelanin can be a protective factor, shielding the cells from toxic effects of redox active metals, toxins, and excess of cytosolic catecholamines. In contrast, neuromelanin released by dying neurons can contribute to the activation of neuroglia triggering the neuroinflammation that characterizes Parkinson's disease. This article reviews recent studies on the molecular aspects of neuromelanin of the human substantia nigra.
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Labandeira-Garcia JL, Rodriguez-Pallares J, Dominguez-Meijide A, Valenzuela R, Villar-Cheda B, Rodríguez-Perez AI. Dopamine-angiotensin interactions in the basal ganglia and their relevance for Parkinson's disease. Mov Disord 2013; 28:1337-42. [PMID: 23925977 DOI: 10.1002/mds.25614] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 04/29/2013] [Accepted: 06/26/2013] [Indexed: 01/08/2023] Open
Abstract
Renin-angiotensin systems are known to act in many tissues, for example, the blood vessel wall or kidney, where a close interaction between angiotensin and dopamine has been demonstrated. Regulatory interactions between the dopaminergic and renin-angiotensin systems have recently been described in the substantia nigra and striatum. In animal models, dopamine depletion induces compensatory overactivation of the local renin-angiotensin system, which primes microglial responses and neuron vulnerability by activating NADPH-oxidase. Hyperactivation of the local renin-angiotensin system exacerbates the inflammatory microglial response, oxidative stress, and dopaminergic degeneration, all of which are inhibited by angiotensin receptor blockers and inhibitors of angiotensin-converting enzymes. In this review we provide evidence suggesting that the renin-angiotensin system may play an important role in dopamine's mediated neuroinflammation and oxidative stress changes in Parkinson's disease. We suggest that manipulating brain angiotensin may constitute an effective neuroprotective strategy for Parkinson's disease.
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Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Faculty of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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Fabricius K, Jacobsen JS, Pakkenberg B. Effect of age on neocortical brain cells in 90+ year old human females--a cell counting study. Neurobiol Aging 2012; 34:91-9. [PMID: 22878165 DOI: 10.1016/j.neurobiolaging.2012.06.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/26/2022]
Abstract
An increasing number of people are living past the age of 100 years, but little is known about what differentiates centenarians from the rest of the population. In this study, brains from female subjects in 3 different age groups, 65-75 years (n = 8), 76-85 years (n = 8), and 94-105 years (n = 7), were examined to estimate the total number of neocortical neurons, astrocytes, oligodendrocytes, and microglia. There was no statistically significant difference in the mean number of neocortical neurons between the 3 groups: 17.9 × 10(9) (CV = SD/mean = 0.15) in the youngest group, 18.1 × 10(9) (CV = 0.22) in the second group, and 16.32 × 10(9) (CV = 0.24) in the oldest group. However, there was a significant difference in the total number of neocortical glial cells between the youngest (41.0 × 10(9)) and oldest (29.0 × 10(9)) age groups (p = 0.013). The significance was probably driven by a significant difference in the total number of neocortical oligodendrocytes that differed significantly between the youngest (27.5 × 10(9)) and oldest (18.1. × 10(9), p = 0.006) age groups. In conclusion, very old individuals have brain neuron numbers comparable with younger individuals, which may be encouraging for those who live into the "fourth age" and may contribute to the longevity of this exceptional group of people.
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Affiliation(s)
- Katrine Fabricius
- Research Laboratory for Stereology and Neuroscience, Bispebjerg University Hospital, Copenhagen, Denmark
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Schumm S, Sebban C, Cohen-Salmon C, Callebert J, Launay JM, Golmard JL, Boussicault L, Petropoulos I, Hild A, Rousselet E, Prigent A, Friguet B, Mariani J, Hirsch EC. Aging of the dopaminergic system and motor behavior in mice intoxicated with the parkinsonian toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. J Neurochem 2012; 122:1032-46. [PMID: 22708926 DOI: 10.1111/j.1471-4159.2012.07837.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication of mice is a standard model of Parkinson's disease (PD). However, it does not reproduce functionally PD. Given the occurrence of PD during aging, symptoms might only be detected in MPTP-intoxicated mice after aging. To address this, mice injected with MPTP at 2.5 months were followed up to a maximum age of 21 months. There was no loss of dopamine cells with aging in control mice; moreover, the initial post-MPTP intoxication decrease in dopamine cell was no longer significant at 21 months. With aging, striatal dopamine level remained constant, but concentrations of the dopamine metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were markedly reduced in both groups. There was also a late impairment of fine motor skills. After MPTP intoxication, hyperactivity was immediately detected and it became greater than in control mice from 14 months of age; fine motor skills were also more impaired; both these symptoms were correlated with striatal dopamine, DOPAC and HVA concentrations. In bothgroups, neither motor symptoms nor dopamine changes worsened with age. These findings do not support the notion that PD develops with age in mice after MPTP intoxication and that the motor deficits seen are because of an aging process.
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Affiliation(s)
- Sophie Schumm
- AP-HP, Hôpital Charles Foix, Unité d'Explorations Fonctionnelles, Ivry-sur-Seine, France.
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The aging striatal dopamine function. Parkinsonism Relat Disord 2011; 18:426-32. [PMID: 22176812 DOI: 10.1016/j.parkreldis.2011.11.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 11/23/2011] [Accepted: 11/27/2011] [Indexed: 11/21/2022]
Abstract
Movement disorders are prevalent in the elderly and may have both central and peripheral origins. Age-related parkinsonism often results in movement disorders identical to some of the cardinal symptoms of typical Parkinson's disease (TPD). Nevertheless, there may be limited similarity in the underlying dysfunction of the sensory-motor circuitry since these two conditions exhibit different changes in the nigro-striatal pathway. In this short review, we highlight some of the key distinctions between aging and TPD regarding striatal dopaminergic activity and discuss them in the context of therapeutic strategies to alleviate motor decline in the elderly.
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Age- and duration-dependent effects of MPTP on cortical serotonin systems. Neurosci Lett 2011; 504:160-164. [PMID: 21964387 DOI: 10.1016/j.neulet.2011.09.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 09/08/2011] [Accepted: 09/14/2011] [Indexed: 12/11/2022]
Abstract
It has been well established that aging is the most prominent risk factor for PD. In the MPTP mouse model which has been widely used to study PD, studies have shown that MPTP exhibits its neurotoxic effects on the dopaminergic system in an age-dependent manner. Although it is recognized the serotonergic system is impacted in PD, how aging influences serotonergic neurodegeneration in PD has not been adequately investigated. In the present studies, we examined the long-term effects of MPTP treatment on regional concentrations of dopamine (DA), serotonin (5-HT) and norepinephrine (NE) in the striatum and prefrontal cortex (PFC). We also determined if there are differences in the age-dependent vulnerability of the monoaminergic system to MPTP. In young (3-month-old) mice, MPTP produced significant decreases in striatal DA but no changes in striatal 5-HT and NE three weeks after MPTP treatment. There was partial recovery of striatal DA concentrations 18 months later. This was accompanied by elevated striatal 5-HT. In the PFC, NE was decreased but there was complete recovery 18 months later. By contrast, we observed a long-term decrease in prefrontal 5-HT with no recovery of 5-HT concentrations 18 months after MPTP treatment. Striatal DA and NE but not 5-HT neurons exhibited age-dependent vulnerability to MPTP. Aging had no influence on the neurotoxic effects of MPTP in the PFC. Thus, there is divergence in the response of DA and 5-HT systems to MPTP neurotoxicity.
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Lee MS, Lyoo CH, Ryu YH, Lim HS, Nam CM, Kim HS, Rinne JO. The effect of age on motor deficits and cerebral glucose metabolism of Parkinson's disease. Acta Neurol Scand 2011; 124:196-201. [PMID: 20880270 DOI: 10.1111/j.1600-0404.2010.01446.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND No systematic study has been made to separate age-related clinical deterioration and dysfunctional brain areas from those associated with Parkinson's disease (PD). METHODS This study included 73 de novo patients with PD and 43 age-matched controls. All subjects underwent [(18)F]-fluorodeoxy glucose (FDG) positron emission tomography studies. The severity of parkinsonian motor deficit was measured using unified PD rating scale (UPDRS) motor scores. Multiple linear regression analysis was used to identify those parkinsonian motor deficits for which severity was correlated with the age of the patients and to locate brain areas in which normalized FDG uptake values were inversely correlated with the age of the subjects. RESULTS Patient age was positively correlated with total UPDRS motor scores and with subscores for bradykinesia and axial motor deficits, but not with subscores for tremor and rigidity. In the control group, an age-related decline in glucose uptake was found only in the cingulate cortex. However, in the patient group, an inverse correlation between age and glucose uptake was observed in the prefrontal, cingulate, orbitofrontal, perisylvian areas, caudate, and thalamus. CONCLUSIONS In PD, widespread age-related decline in cerebral function may exaggerate the deterioration associated with bradykinesia and the axial motor deficits associated with nigral neuronal loss.
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Affiliation(s)
- M S Lee
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
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46
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Braak H, Del Tredici K. Non‐Dopaminergic Pathology of Parkinson's Disease. PARKINSON'S DISEASE 2011. [DOI: 10.1002/9781444397970.ch3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Collier TJ, Kanaan NM, Kordower JH. Ageing as a primary risk factor for Parkinson's disease: evidence from studies of non-human primates. Nat Rev Neurosci 2011; 12:359-66. [PMID: 21587290 DOI: 10.1038/nrn3039] [Citation(s) in RCA: 296] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ageing is the greatest risk factor for the development of Parkinson's disease. However, the current dogma holds that cellular mechanisms that are associated with ageing of midbrain dopamine neurons and those that are related to dopamine neuron degeneration in Parkinson's disease are unrelated. We propose, based on evidence from studies of non-human primates, that normal ageing and the degeneration of dopamine neurons in Parkinson's disease are linked by the same cellular mechanisms and, therefore, that markers of cellular risk factors accumulate with age in a pattern that mimics the pattern of degeneration observed in Parkinson's disease. We contend that ageing induces a pre-parkinsonian state, and that the cellular mechanisms of dopamine neuron demise during normal ageing are accelerated or exaggerated in Parkinson's disease through a combination of genetic and environmental factors.
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Affiliation(s)
- Timothy J Collier
- Division of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan 49503, USA.
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48
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González-Hernández T, Cruz-Muros I, Afonso-Oramas D, Salas-Hernandez J, Castro-Hernandez J. Vulnerability of mesostriatal dopaminergic neurons in Parkinson's disease. Front Neuroanat 2010; 4:140. [PMID: 21079748 PMCID: PMC2978035 DOI: 10.3389/fnana.2010.00140] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 09/24/2010] [Indexed: 12/21/2022] Open
Abstract
The term vulnerability was first associated with the midbrain dopaminergic neurons 85 years ago, before they were identified as monoaminergic neurons, when Foix and Nicolesco (1925) reported the loss of neuromelanin containing neurons in the midbrain of patients with post-encephalitic Parkinson's disease (PD). A few years later, Hassler (1938) showed that degeneration is more intense in the ventral tier of the substantia nigra compacta than in its dorsal tier and the ventral tegmental area (VTA), outlining the concept of differential vulnerability of midbrain dopaminergic (DA-) neurons. Nowadays, we know that other neuronal groups degenerate in PD, but the massive loss of nigral DA-cells is its pathological hallmark, having a pivotal position in the pathophysiology of the disease as it is responsible for the motor symptoms. Data from humans as well as cellular and animal models indicate that DA-cell degeneration is a complex process, probably precipitated by the convergence of different risk factors, mediated by oxidative stress, and involving pathogenic factors arising within the DA-neuron (intrinsic factors), and from its environment and distant interconnected brain regions (extrinsic factors). In light of current data, intrinsic factors seem to be preferentially involved in the first steps of the degenerative process, and extrinsic factors in its progression. A controversial issue is the relative weight of the impairment of common cell functions, such as energy metabolism and proteostasis, and specific dopaminergic functions, such as pacemaking activity and DA handling, in the pathogenesis of DA-cell degeneration. Here we will review the current knowledge about the relevance of these factors at the beginning and during the progression of PD, and in the differential vulnerability of midbrain DA-cells.
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49
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Eriksen N, Stark AK, Pakkenberg B. Age and Parkinson's disease-related neuronal death in the substantia nigra pars compacta. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2010:203-13. [PMID: 20411779 DOI: 10.1007/978-3-211-92660-4_16] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
During aging, decline in memory and cognitive abilities as well as motor weakening is of great concern. The dopaminergic system mediates some aspects of manual dexterity, in addition to cognition and emotion, and may be especially vulnerable to aging. A common neurodegenerative disorder of this system, Parkinson's disease, is characterized by a selective, progressive loss of dopaminergic neurons in the substantia nigra pars compacta. This review includes studies quantifying age and Parkinson's-related changes of the substantia nigra, with emphasis on stereological studies performed in the substantia nigra pars compacta.
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Affiliation(s)
- Nina Eriksen
- Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark.
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50
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Troiano AR, Schulzer M, Fuente-Fernandez RDL, Mak E, Mckenzie J, Sossi V, Mccormick S, Ruth TJ, Stoessl AJ. Dopamine transporter PET in normal aging: Dopamine transporter decline and its possible role in preservation of motor function. Synapse 2010; 64:146-51. [DOI: 10.1002/syn.20708] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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