scholarly journals Successful and Unsuccessful Brain Aging in Pets: Pathophysiological Mechanisms behind Clinical Signs and Potential Benefits from Palmitoylethanolamide Nutritional Intervention

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2584
Author(s):  
Caterina Scuderi ◽  
Lorenzo Golini
Keyword(s):  
Molecular Mechanisms ◽  
Brain Aging ◽  
Neurodegenerative Disorder ◽  
Disease Onset ◽  
Clinical Signs ◽  
Endocannabinoid System ◽  
Nutritional Intervention ◽  
Underlying Disease ◽  
Age Related ◽  
Ultramicronized Palmitoylethanolamide

Canine and feline cognitive dysfunction syndrome is a common neurodegenerative disorder of old age and a natural model of human Alzheimer’s disease. With the unavoidable expanding life expectancy, an increasing number of small animals will be affected. Although there is no cure, early detection and intervention are vitally important to delay cognitive decline. Knowledge of cellular and molecular mechanisms underlying disease onset and progression is an equally decisive factor for developing effective approaches. Uncontrolled neuroinflammation, orchestrated in the central nervous system mainly by astrocytes, microglia, and resident mast cells, is currently acknowledged as a hallmark of neurodegeneration. This has prompted scientists to find a way to rebalance the altered crosstalk between these cells. In this context, great emphasis has been given to the role played by the expanded endocannabinoid system, i.e., endocannabinoidome, because of its prominent role in physiological and pathological neuroinflammation. Within the endocannabinoidome, great attention has been paid to palmitoylethanolamide due to its safe and pro-homeostatic effects. The availability of new ultramicronized formulations highly improved the oral bioavailability of palmitoylethanolamide, paving the way to its dietary use. Ultramicronized palmitoylethanolamide has been repeatedly tested in animal models of age-related neurodegeneration with promising results. Data accumulated so far suggest that supplementation with ultramicronized palmitoylethanolamide helps to accomplish successful brain aging.

scholarly journals CIB2 regulates mTORC1 signaling and is essential for autophagy and visual function

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Saumil Sethna ◽  
Patrick A. Scott ◽  
Arnaud P. J. Giese ◽  
Todd Duncan ◽  
Xiaoying Jian ◽  
...  
Keyword(s):  
Visual Function ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Negative Regulator ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Mtorc1 Signaling ◽  
Marked Accumulation

AbstractAge-related macular degeneration (AMD) is a multifactorial neurodegenerative disorder. Although molecular mechanisms remain elusive, deficits in autophagy have been associated with AMD. Here we show that deficiency of calcium and integrin binding protein 2 (CIB2) in mice, leads to age-related pathologies, including sub-retinal pigment epithelium (RPE) deposits, marked accumulation of drusen markers APOE, C3, Aβ, and esterified cholesterol, and impaired visual function, which can be rescued using exogenous retinoids. Cib2 mutant mice exhibit reduced lysosomal capacity and autophagic clearance, and increased mTORC1 signaling—a negative regulator of autophagy. We observe concordant molecular deficits in dry-AMD RPE/choroid post-mortem human tissues. Mechanistically, CIB2 negatively regulates mTORC1 by preferentially binding to ‘nucleotide empty’ or inactive GDP-loaded Rheb. Upregulated mTORC1 signaling has been implicated in lymphangioleiomyomatosis (LAM) cancer. Over-expressing CIB2 in LAM patient-derived fibroblasts downregulates hyperactive mTORC1 signaling. Thus, our findings have significant implications for treatment of AMD and other mTORC1 hyperactivity-associated disorders.

scholarly journals Psychomotor impairments and therapeutic implications revealed by a mutation associated with infantile Parkinsonism-Dystonia

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jenny I Aguilar ◽  
Mary Hongying Cheng ◽  
Josep Font ◽  
Alexandra C Schwartz ◽  
Kaitlyn Ledwitch ◽  
...  
Keyword(s):  
High Speed ◽  
Molecular Mechanisms ◽  
Motor Coordination ◽  
Neurodegenerative Disorder ◽  
Expression System ◽  
Distinct Type ◽  
Underlying Disease ◽  
Deficiency Syndrome ◽  
Motor Deficits ◽  
Therapeutic Implications

Parkinson disease (PD) is a progressive, neurodegenerative disorder affecting over 6.1 million people worldwide. Although the cause of PD remains unclear, studies of highly penetrant mutations identified in early-onset familial parkinsonism have contributed to our understanding of the molecular mechanisms underlying disease pathology. Dopamine (DA) transporter (DAT) deficiency syndrome (DTDS) is a distinct type of infantile parkinsonism-dystonia that shares key clinical features with PD, including motor deficits (progressive bradykinesia, tremor, hypomimia) and altered DA neurotransmission. Here, we define structural, functional, and behavioral consequences of a Cys substitution at R445 in human DAT (hDAT R445C), identified in a patient with DTDS. We found that this R445 substitution disrupts a phylogenetically conserved intracellular (IC) network of interactions that compromise the hDAT IC gate. This is demonstrated by both Rosetta molecular modeling and fine-grained simulations using hDAT R445C, as well as EPR analysis and X-ray crystallography of the bacterial homolog leucine transporter. Notably, the disruption of this IC network of interactions supported a channel-like intermediate of hDAT and compromised hDAT function. We demonstrate that Drosophila melanogaster expressing hDAT R445C show impaired hDAT activity, which is associated with DA dysfunction in isolated brains and with abnormal behaviors monitored at high-speed time resolution. We show that hDAT R445C Drosophila exhibit motor deficits, lack of motor coordination (i.e. flight coordination) and phenotypic heterogeneity in these behaviors that is typically associated with DTDS and PD. These behaviors are linked with altered dopaminergic signaling stemming from loss of DA neurons and decreased DA availability. We rescued flight coordination with chloroquine, a lysosomal inhibitor that enhanced DAT expression in a heterologous expression system. Together, these studies shed some light on how a DTDS-linked DAT mutation underlies DA dysfunction and, possibly, clinical phenotypes shared by DTDS and PD.

scholarly journals RNA Dynamics in Alzheimer’s Disease

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5113
Author(s):  
Agnieszka Rybak-Wolf ◽  
Mireya Plass
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Neurodegenerative Disorder ◽  
Rna Binding Proteins ◽  
Current Evidence ◽  
Circular Rnas ◽  
Rna Dynamics ◽  
Age Related

Alzheimer’s disease (AD) is the most common age-related neurodegenerative disorder that heavily burdens healthcare systems worldwide. There is a significant requirement to understand the still unknown molecular mechanisms underlying AD. Current evidence shows that two of the major features of AD are transcriptome dysregulation and altered function of RNA binding proteins (RBPs), both of which lead to changes in the expression of different RNA species, including microRNAs (miRNAs), circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and messenger RNAs (mRNAs). In this review, we will conduct a comprehensive overview of how RNA dynamics are altered in AD and how this leads to the differential expression of both short and long RNA species. We will describe how RBP expression and function are altered in AD and how this impacts the expression of different RNA species. Furthermore, we will also show how changes in the abundance of specific RNA species are linked to the pathology of AD.

scholarly journals Cannabinoid Receptor 2 Alters Social Memory and Microglial Activity in an Age-Dependent Manner

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5984
Author(s):  
Joanna Agnieszka Komorowska-Müller ◽  
Tanushka Rana ◽  
Bolanle Fatimat Olabiyi ◽  
Andreas Zimmer ◽  
Anne-Caroline Schmöle
Keyword(s):  
Cannabinoid Receptor ◽  
Social Memory ◽  
Brain Aging ◽  
Endocannabinoid System ◽  
Immunohistochemical Analysis ◽  
Cellular Level ◽  
Spatial Learning And Memory ◽  
Dependent Manner ◽  
Cannabinoid Receptor 2 ◽  
Age Related

Physiological brain aging is characterized by gradual, substantial changes in cognitive ability, accompanied by chronic activation of the neural immune system. This form of inflammation, termed inflammaging, in the central nervous system is primarily enacted through microglia, the resident immune cells. The endocannabinoid system, and particularly the cannabinoid receptor 2 (CB2R), is a major regulator of the activity of microglia and is upregulated under inflammatory conditions. Here, we elucidated the role of the CB2R in physiological brain aging. We used CB2R−/− mice of progressive ages in a behavioral test battery to assess social and spatial learning and memory. This was followed by detailed immunohistochemical analysis of microglial activity and morphology, and of the expression of pro-inflammatory cytokines in the hippocampus. CB2R deletion decreased social memory in young mice, but did not affect spatial memory. In fact, old CB2R−/− mice had a slightly improved social memory, whereas in WT mice we detected an age-related cognitive decline. On a cellular level, CB2R deletion increased lipofuscin accumulation in microglia, but not in neurons. CB2R−/− microglia showed an increase of activity markers Iba1 and CD68, and minor upregulation in tnfa and il6 expression and downregulation of ccl2 with age. This was accompanied by a change in morphology as CB2R−/− microglia had smaller somas and lower polarity, with increased branching, cell volume, and tree length. We present that CB2Rs are involved in cognition and age-induced microglial activity, but may also be important for microglial activation itself.

scholarly journals Ionizing Radiation-Induced Brain Cell Aging and the Potential Underlying Molecular Mechanisms

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3570
Author(s):  
Qin-Qi Wang ◽  
Gang Yin ◽  
Jiang-Rong Huang ◽  
Shi-Jun Xi ◽  
Feng Qian ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Global Economy ◽  
Molecular Mechanisms ◽  
Brain Aging ◽  
Healthcare Services ◽  
Cell Aging ◽  
Extrinsic Factors ◽  
Neuropsychological Disorders ◽  
Age Related ◽  
Radiation Induced

Population aging is occurring rapidly worldwide, challenging the global economy and healthcare services. Brain aging is a significant contributor to various age-related neurological and neuropsychological disorders, including Alzheimer’s disease and Parkinson’s disease. Several extrinsic factors, such as exposure to ionizing radiation, can accelerate senescence. Multiple human and animal studies have reported that exposure to ionizing radiation can have varied effects on organ aging and lead to the prolongation or shortening of life span depending on the radiation dose or dose rate. This paper reviews the effects of radiation on the aging of different types of brain cells, including neurons, microglia, astrocytes, and cerebral endothelial cells. Further, the relevant molecular mechanisms are discussed. Overall, this review highlights how radiation-induced senescence in different cell types may lead to brain aging, which could result in the development of various neurological and neuropsychological disorders. Therefore, treatment targeting radiation-induced oxidative stress and neuroinflammation may prevent radiation-induced brain aging and the neurological and neuropsychological disorders it may cause.

scholarly journals Amyloidosis in Alzheimer’s Disease: The Toxicity of Amyloid Beta (Aβ), Mechanisms of Its Accumulation and Implications of Medicinal Plants for Therapy

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Anchalee Prasansuklab ◽  
Tewin Tencomnao
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Herbal Medicines ◽  
Underlying Disease ◽  
Current Therapy ◽  
The Central Nervous System ◽  
Number Of Individuals

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that leads to memory deficits and death. While the number of individuals with AD is rising each year due to the longer life expectancy worldwide, current therapy can only somewhat relieve the symptoms of AD. There is no proven medication to cure or prevent the disease, possibly due to a lack of knowledge regarding the molecular mechanisms underlying disease pathogenesis. Most previous studies have accepted the “amyloid hypothesis,” in which the neuropathogenesis of AD is believed to be triggered by the accumulation of the toxic amyloid beta (Aβ) protein in the central nervous system (CNS). Lately, knowledge that may be critical to unraveling the hidden pathogenic pathway of AD has been revealed. This review concentrates on the toxicity of Aβand the mechanism of accumulation of this toxic protein in the brain of individuals with AD and also summarizes recent advances in the study of these accumulation mechanisms together with the role of herbal medicines that could facilitate the development of more effective therapeutic and preventive strategies.

scholarly journals Amyloid beta acts synergistically as a pro-inflammatory cytokine

2020 ◽  
Author(s):  
Thomas J. LaRocca ◽  
Alyssa N. Cavalier ◽  
Christine M. Roberts ◽  
Maddie R. Lemieux ◽  
Christopher D. Link
Keyword(s):  
Amyloid Beta ◽  
Brain Aging ◽  
Neurodegenerative Disorder ◽  
Biological Action ◽  
Rna Seq ◽  
Transcriptional Signature ◽  
Age Related ◽  
Low Concentrations ◽  
A Cell

SUMMARYThe amyloid beta (Aβ) peptide is believed to play a central role in Alzheimer’s disease (AD), the most common age-related neurodegenerative disorder. However, the natural, evolutionarily-selected functions of Aβ are incompletely understood. Here, we report that nanomolar concentrations of Aβ act synergistically with known cytokines to promote pro-inflammatory activation in primary human astrocytes (a cell type increasingly implicated in brain aging and AD). Using transcriptomics (RNA-seq), we show that Aβ can directly substitute for the complement component C1q in a cytokine cocktail previously shown to induce astrocyte immune activation. Furthermore, we show that astrocytes synergistically activated by Aβ have a transcriptional signature similar to neurotoxic “A1” astrocytes known to accumulate with age and in AD. Interestingly, we find that this biological action of Aβ at low concentrations is distinct from the transcriptome changes induced by the high/supraphysiological doses of Aβ often used in in vitro studies. Collectively, our results suggest an important, cytokine-like function for Aβ and a novel mechanism by which it may directly contribute to the neuroinflammation associated with brain aging and AD.

scholarly journals The endocannabinoid system in normal and pathological brain ageing

2012 ◽  
Vol 367 (1607) ◽  
pp. 3326-3341 ◽  
Author(s):  
Andras Bilkei-Gorzo
Keyword(s):  
Molecular Mechanisms ◽  
Endocannabinoid System ◽  
System Level ◽  
Mitochondrial Activity ◽  
Normal Brain ◽  
Neuroprotective Effects ◽  
Cannabinoid System ◽  
Age Related ◽  
Brain Ageing

The role of endocannabinoids as inhibitory retrograde transmitters is now widely known and intensively studied. However, endocannabinoids also influence neuronal activity by exerting neuroprotective effects and regulating glial responses. This review centres around this less-studied area, focusing on the cellular and molecular mechanisms underlying the protective effect of the cannabinoid system in brain ageing. The progression of ageing is largely determined by the balance between detrimental, pro-ageing, largely stochastic processes, and the activity of the homeostatic defence system. Experimental evidence suggests that the cannabinoid system is part of the latter system. Cannabinoids as regulators of mitochondrial activity, as anti-oxidants and as modulators of clearance processes protect neurons on the molecular level. On the cellular level, the cannabinoid system regulates the expression of brain-derived neurotrophic factor and neurogenesis. Neuroinflammatory processes contributing to the progression of normal brain ageing and to the pathogenesis of neurodegenerative diseases are suppressed by cannabinoids, suggesting that they may also influence the ageing process on the system level. In good agreement with the hypothesized beneficial role of cannabinoid system activity against brain ageing, it was shown that animals lacking CB1 receptors show early onset of learning deficits associated with age-related histological and molecular changes. In preclinical models of neurodegenerative disorders, cannabinoids show beneficial effects, but the clinical evidence regarding their efficacy as therapeutic tools is either inconclusive or still missing.

scholarly journals Age-Related Oxidative Changes in Primary Porcine Fibroblasts Expressing Mutated Huntingtin

2019 ◽  
Vol 19 (1) ◽  
pp. 22-34
Author(s):  
Petra Smatlikova ◽  
Georgina Askeland ◽  
Michaela Vaskovicova ◽  
Jiri Klima ◽  
Jan Motlik ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Nuclear Dna ◽  
Neurodegenerative Disorder ◽  
Cyclin B1 ◽  
Gene Encoding ◽  
Proliferation Capacity ◽  
Mitochondrial Superoxide ◽  
Age Related ◽  
The Impact

Background: Huntington’s disease (HD) is a devastating neurodegenerative disorder caused by CAG triplet expansions in the huntingtin gene. Oxidative stress is linked to HD pathology, although it is not clear whether this is an effect or a mediator of disease. The transgenic (TgHD) minipig expresses the N-terminal part of human-mutated huntingtin and represents a unique model to investigate therapeutic strategies towards HD. A more detailed characterization of this model is needed to fully utilize its potential. Methods: In this study, we focused on the molecular and cellular features of fibroblasts isolated from TgHD minipigs and the wild-type (WT) siblings at different ages, pre-symptomatic at the age of 24–36 months and with the onset of behavioural symptoms at the age of 48 months. We measured oxidative stress, the expression of oxidative stress-related genes, proliferation capacity along with the expression of cyclin B1 and D1 proteins, cellular permeability, and the integrity of the nuclear DNA (nDNA) and mitochondrial DNA in these cells. Results: TgHD fibroblasts isolated from 48-month-old animals showed increased oxidative stress, which correlated with the overexpression of SOD2 encoding mitochondrial superoxide dismutase 2, and the NEIL3 gene encoding DNA glycosylase involved in replication-associated repair of oxidized DNA. TgHD cells displayed an abnormal proliferation capacity and permeability. We further demonstrated increased nDNA damage in pre-symptomatic TgHD fibroblasts (isolated from animals aged 24–36 months). Conclusions: Our results unravel phenotypic alterations in primary fibroblasts isolated from the TgHD minipig model at the age of 48 months. Importantly, nDNA damage appears to precede these phenotypic alterations. Our results highlight the impact of fibroblasts from TgHD minipigs in studying the molecular mechanisms of HD pathophysiology that gradually occur with age.

scholarly journals Psychomotor Impairments and Therapeutic Implications Revealed by a Mutation Associated with Infantile Parkinsonism-Dystonia

2021 ◽  
Author(s):  
Jenny I. Aguilar ◽  
Mary Hongying Cheng ◽  
Josep Font ◽  
Alexandra C. Schwartz ◽  
Kaitlyn Ledwitch ◽  
...  
Keyword(s):  
High Speed ◽  
Molecular Mechanisms ◽  
Motor Coordination ◽  
Neurodegenerative Disorder ◽  
Distinct Type ◽  
Surface Expression ◽  
Underlying Disease ◽  
Deficiency Syndrome ◽  
Motor Deficits ◽  
Therapeutic Implications

ABSTRACTParkinson disease (PD) is a progressive, neurodegenerative disorder affecting over 6.1 million people worldwide. Although the cause of PD remains unclear, studies of highly-penetrant mutations identified in early-onset familial parkinsonism have contributed to our understanding of the molecular mechanisms underlying disease pathology. Dopamine (DA) transporter (DAT) deficiency syndrome (DTDS) is a distinct type of infantile parkinsonism-dystonia that shares key clinical features with PD, including motor deficits (progressive bradykinesia, tremor, hypomimia) and altered DA neurotransmission. Here, we define structural, functional, and behavioral consequences of a Cys substitution at R445 in human DAT (hDAT R445C), identified in a patient with DTDS. We found that this R445 substitution disrupts a phylogenetically conserved intracellular (IC) network of interactions that compromise the hDAT IC gate. This is demonstrated by both Rosetta molecular modeling and fine-grained simulations using hDAT R445C, as well as EPR analysis and X-ray crystallography of the bacterial homolog leucine transporter. Notably, the disruption of this IC network of interactions supported a channel-like intermediate of hDAT and compromised hDAT function. We demonstrate that Drosophila melanogaster expressing hDAT R445C show impaired hDAT activity, which is associated with DA dysfunction in isolated brains and with abnormal behaviors monitored at high-speed time resolution.We show that hDAT R445C Drosophila exhibit motor deficits, lack of motor coordination (i.e. flight coordination) and phenotypic heterogeneity in these behaviors that is typically associated with DTDS and PD. These behaviors are linked with altered dopaminergic signaling stemming from loss of DA neurons and decreased DA availability. We rescued flight coordination through enhanced DAT surface expression via the lysosomal inhibitor chloroquine. Together, these studies shed light on how a DTDS-linked DAT mutation underlies DA dysfunction and, more broadly, the clinical phenotypes shared by DTDS and PD.

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