scholarly journals Cellular Senescence in Brain Aging

2021 ◽  
Vol 13 ◽  
Author(s):  
Ewa Sikora ◽  
Anna Bielak-Zmijewska ◽  
Magdalena Dudkowska ◽  
Adam Krzystyniak ◽  
Grazyna Mosieniak ◽  
...  
Keyword(s):  
Glial Cells ◽  
Cellular Senescence ◽  
Dendritic Spines ◽  
Neuronal Plasticity ◽  
Brain Aging ◽  
Aging Brain ◽  
Peripheral Tissues ◽  
Brain Functions ◽  
The Brain

Aging of the brain can manifest itself as a memory and cognitive decline, which has been shown to frequently coincide with changes in the structural plasticity of dendritic spines. Decreased number and maturity of spines in aged animals and humans, together with changes in synaptic transmission, may reflect aberrant neuronal plasticity directly associated with impaired brain functions. In extreme, a neurodegenerative disease, which completely devastates the basic functions of the brain, may develop. While cellular senescence in peripheral tissues has recently been linked to aging and a number of aging-related disorders, its involvement in brain aging is just beginning to be explored. However, accumulated evidence suggests that cell senescence may play a role in the aging of the brain, as it has been documented in other organs. Senescent cells stop dividing and shift their activity to strengthen the secretory function, which leads to the acquisition of the so called senescence-associated secretory phenotype (SASP). Senescent cells have also other characteristics, such as altered morphology and proteostasis, decreased propensity to undergo apoptosis, autophagy impairment, accumulation of lipid droplets, increased activity of senescence-associated-β-galactosidase (SA-β-gal), and epigenetic alterations, including DNA methylation, chromatin remodeling, and histone post-translational modifications that, in consequence, result in altered gene expression. Proliferation-competent glial cells can undergo senescence both in vitro and in vivo, and they likely participate in neuroinflammation, which is characteristic for the aging brain. However, apart from proliferation-competent glial cells, the brain consists of post-mitotic neurons. Interestingly, it has emerged recently, that non-proliferating neuronal cells present in the brain or cultivated in vitro can also have some hallmarks, including SASP, typical for senescent cells that ceased to divide. It has been documented that so called senolytics, which by definition, eliminate senescent cells, can improve cognitive ability in mice models. In this review, we ask questions about the role of senescent brain cells in brain plasticity and cognitive functions impairments and how senolytics can improve them. We will discuss whether neuronal plasticity, defined as morphological and functional changes at the level of neurons and dendritic spines, can be the hallmark of neuronal senescence susceptible to the effects of senolytics.

scholarly journals Impaired Mitophagy in Neurons and Glial Cells during Aging and Age-Related Disorders

2021 ◽  
Vol 22 (19) ◽  
pp. 10251
Author(s):  
Vladimir Sukhorukov ◽  
Dmitry Voronkov ◽  
Tatiana Baranich ◽  
Natalia Mudzhiri ◽  
Alina Magnaeva ◽  
...  
Keyword(s):  
Glial Cells ◽  
Brain Aging ◽  
Cellular Level ◽  
Aging Brain ◽  
The Past ◽  
Age Related ◽  
Accumulation Of Damage ◽  
Quantity Control ◽  
The Brain

Aging is associated with a decline in cognitive function, which can partly be explained by the accumulation of damage to the brain cells over time. Neurons and glia undergo morphological and ultrastructure changes during aging. Over the past several years, it has become evident that at the cellular level, various hallmarks of an aging brain are closely related to mitophagy. The importance of mitochondria quality and quantity control through mitophagy is highlighted by the contribution that defects in mitochondria–autophagy crosstalk make to aging and age-related diseases. In this review, we analyze some of the more recent findings regarding the study of brain aging and neurodegeneration in the context of mitophagy. We discuss the data on the dynamics of selective autophagy in neurons and glial cells during aging and in the course of neurodegeneration, focusing on three mechanisms of mitophagy: non-receptor-mediated mitophagy, receptor-mediated mitophagy, and transcellular mitophagy. We review the role of mitophagy in neuronal/glial homeostasis and in the molecular pathogenesis of neurodegenerative disorders, such as Parkinson’s disease, Alzheimer’s disease, and other disorders. Common mechanisms of aging and neurodegeneration that are related to different mitophagy pathways provide a number of promising targets for potential therapeutic agents.

scholarly journals The Arc of Astrocyte Aging: Insights From scRNAseq

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 372-372
Author(s):  
Christopher Minteer ◽  
Morgan Levine ◽  
Margarita Meer
Keyword(s):  
Single Cell ◽  
Cellular Senescence ◽  
Brain Aging ◽  
Epigenetic Alterations ◽  
Aging Studies ◽  
Single Cell Rna Sequencing ◽  
Transcriptional Changes ◽  
The Brain ◽  
Human And Mouse

Abstract There is an urgent need to increase our understanding of brain aging and its role in neurodegeneration. While, evidence suggest that many hallmarks of aging, including epigenetic alterations and cellular senescence may be implicated in dementia, studying these and other progressive molecular changes in the brain remains extremely challenging. We asked whether something as simple as artificially aging cells in culture could recapitulate the changes that occur during organismal aging. To test this, we passaged human primary astrocytes and performed single-cell RNA sequencing (scRNAseq) of cells at passages 2-10. We observe that the sequential passaging—that terminates with a cluster of senescent cells—can be captured by manifolds and used to quantify a pseudo-time measure of progressive transcriptional changes. We identify genes underlying this transition and apply this signature of in vitro astrocyte passaging to scRNAseq from human and mouse brain aging studies, demonstrating associations with aging and neuropathology.

scholarly journals The Cellular Senescence Stress Response in Post-Mitotic Brain Cells: Cell Survival at the Expense of Tissue Degeneration

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 229
Author(s):  
Eric Sah ◽  
Sudarshan Krishnamurthy ◽  
Mohamed Y. Ahmidouch ◽  
Gregory J. Gillispie ◽  
Carol Milligan ◽  
...  
Keyword(s):  
Stress Response ◽  
Cell Fate ◽  
Cellular Senescence ◽  
Cell Biology ◽  
Brain Aging ◽  
Complex Stress ◽  
Brain Cell ◽  
Tissue Degeneration ◽  
Cellular Dna

In 1960, Rita Levi-Montalcini and Barbara Booker made an observation that transformed neuroscience: as neurons mature, they become apoptosis resistant. The following year Leonard Hayflick and Paul Moorhead described a stable replicative arrest of cells in vitro, termed “senescence”. For nearly 60 years, the cell biology fields of neuroscience and senescence ran in parallel, each separately defining phenotypes and uncovering molecular mediators to explain the 1960s observations of their founding mothers and fathers, respectively. During this time neuroscientists have consistently observed the remarkable ability of neurons to survive. Despite residing in environments of chronic inflammation and degeneration, as occurs in numerous neurodegenerative diseases, often times the neurons with highest levels of pathology resist death. Similarly, cellular senescence (hereon referred to simply as “senescence”) now is recognized as a complex stress response that culminates with a change in cell fate. Instead of reacting to cellular/DNA damage by proliferation or apoptosis, senescent cells survive in a stable cell cycle arrest. Senescent cells simultaneously contribute to chronic tissue degeneration by secreting deleterious molecules that negatively impact surrounding cells. These fields have finally collided. Neuroscientists have begun applying concepts of senescence to the brain, including post-mitotic cells. This initially presented conceptual challenges to senescence cell biologists. Nonetheless, efforts to understand senescence in the context of brain aging and neurodegenerative disease and injury emerged and are advancing the field. The present review uses pre-defined criteria to evaluate evidence for post-mitotic brain cell senescence. A closer interaction between neuro and senescent cell biologists has potential to advance both disciplines and explain fundamental questions that have plagued their fields for decades.

scholarly journals Emergence Of Consciousness And Qualia From A Complex Brain

Folia Medica ◽  
2014 ◽  
Vol 56 (4) ◽  
pp. 289-296
Author(s):  
Jakob Korf
Keyword(s):  
System Theory ◽  
General System ◽  
Resolution Power ◽  
Brain Functions ◽  
Scientific Exploration ◽  
Brain Changes ◽  
Higher Brain Functions ◽  
The Brain

Abstract Qualia are private conscious experiences of which the associated feelings can be reported to other people. Whether qualia are amenable to scientific exploration has often been questioned, which is challenged by the present article. The following arguments are given: 1. the configuration of the brain changes continuously and irreversibly, because of genetic and environmental influences and interhuman communication; 2. qualia and consciousness are processes, rather than states; 3. private feelings, including those associated with qualia, should be positioned in the context of a personal brain as being developed during life; 4. consciousness and qualia should be understood in the context of general system theory, thus concluding that isolated, in vitro, properties of neurons and other brain constituents might marginally contribute to the understanding of higher brain functions, mind or qualia; 5. current in vivo approaches have too little resolution power - in terms of space and time - to delineate individual and subjective brain processes. When subtle personalized properties of the nervous system can be assessed in vivo or in vitro, qualia can scientifically be investigated. We discuss some approaches to overcome these barriers.

scholarly journals A novel antioxidant ergothioneine PET radioligand for in vivo imaging applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
William J. Behof ◽  
Clayton A. Whitmore ◽  
Justin R. Haynes ◽  
Adam J. Rosenberg ◽  
Mohammed N. Tantawy ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mouse Model ◽  
Peripheral Tissues ◽  
Molar Activity ◽  
Model Of Alzheimer’S Disease ◽  
Specific Retention ◽  
5Xfad Mice ◽  
The Brain

AbstractErgothioneine (ERGO) is a rare amino acid mostly found in fungi, including mushrooms, with recognized antioxidant activity to protect tissues from damage by reactive oxygen species (ROS) components. Prior to this publication, the biodistribution of ERGO has been performed solely in vitro using extracted tissues. The aim of this study was to develop a feasible chemistry for the synthesis of an ERGO PET radioligand, [11C]ERGO, to facilitate in vivo study. The radioligand probe was synthesized with identical structure to ERGO by employing an orthogonal protection/deprotection approach. [11C]methylation of the precursor was performed via [11C]CH3OTf to provide [11C]ERGO radioligand. The [11C]ERGO was isolated by RP-HPLC with a molar activity of 690 TBq/mmol. To demonstrate the biodistribution of the radioligand, we administered approximately 37 MBq/0.1 mL in 5XFAD mice, a mouse model of Alzheimer’s disease via the tail vein. The distribution of ERGO in the brain was monitored using 90-min dynamic PET scans. The delivery and specific retention of [11C]ERGO in an LPS-mediated neuroinflammation mouse model was also demonstrated. For the pharmacokinetic study, the concentration of the compound in the serum started to decrease 10 min after injection while starting to distribute in other peripheral tissues. In particular, a significant amount of the compound was found in the eyes and small intestine. The radioligand was also distributed in several regions of the brain of 5XFAD mice, and the signal remained strong 30 min post-injection. This is the first time the biodistribution of this antioxidant and rare amino acid has been demonstrated in a preclinical mouse model in a highly sensitive and non-invasive manner.

scholarly journals A study on Dowager Cixi’s Yanling-Yishou-Dan of Qing Dynasty in a Japanese laboratory of biochemistry and molecular biology in 1990s: An attempt for TCM modernization

2021 ◽  
pp. 1-21
Author(s):  
Jiankang Liu
Keyword(s):  
Qing Dynasty ◽  
Brain Homogenate ◽  
Modern Technology ◽  
Toxicity Tests ◽  
Brain Functions ◽  
Great Progress ◽  
Theoretical Evidence ◽  
The Brain

Traditional Chinese Medicine (TCM) modernization has been proposed for many years, but the progress is still slow due to both ideological and technical obstacles. When I went to Japan in 1989, I found Japan has made a great progress on TCM by using modern technology. Therefore, I have studied a fine extract prepared from medicinal herbs (renamed Yi-Zhi-Yi-Shou, YZYS), a prescription of Dowager Cixi’s Yanling-Yishou-Dan of Qing Dynasty, with the current drug investigation strategies. I examined its antioxidant activity both in vitro and in vivo. The in-vitro studies found that YZYS possesses strong antioxidant capacity, such as scavenging various kinds of free radicals, and inhibits free radical-induced peroxidation of brain homogenate, microsomes, mitochondria, amino acids, deoxyribose and DNA. The in-vivo study with immobilization-induced emotional stress in rats, showed that YZYS effectively inhibits stress-induced stomach ulcers and oxidative damage in plasma and the brain. In addition, YZYS is shown to be non-toxic in both acute and chronic toxicity tests. These studies demonstrate that YZYS is a potent natural antioxidant and offer theoretical evidence for the beneficial effect of YZYS on health and brain functions, and that TCM prescriptions can be studied scientifically as modern medical drugs.

scholarly journals Changes of Cholinesterase Activity in the Erythrocytes, Plasma, Diaphragm, Liver and Various Parts of the Brain in the Rabbit Following Transfusion of Erythrocytes with Soman Inhibited Acetylcholinesterase

1997 ◽  
Vol 40 (2) ◽  
pp. 37-39
Author(s):  
Jiří Kassa ◽  
Jiří Bajgar ◽  
Josef Fusek
Keyword(s):  
Blood Transfusion ◽  
Cholinesterase Activity ◽  
Acetylcholinesterase Activity ◽  
Significant Inhibition ◽  
Peripheral Compartment ◽  
Peripheral Tissues ◽  
Cholinesterase Activities ◽  
The Brain

1. The changes of cholinesterase activity in rabbit blood, peripheral tissues and the central nervous system following transfusion of erythrocytes with soman inhibited acetylcholinesterase were demonstrated. 2. After incubation with soman for 0.5 or 24 h, erythrocytes without acetylcholinesterase activity were injected to intact rabbits and cholinesterase activity in the erythrocytes, plasma, diaphragm, liver and various parts of the brain were evaluated 24 h following blood-transfusion. 3. When erythrocytes were incubated with soman for 24 h, no changes of cholinesterase activity in the rabbit following blood-transfusion were observed with an exception of erythrocyte acetylcholinesterase. 4. When erythrocytes were incubated with soman for 0.5 h, a significant decrease in cholinesterase activity in the erythrocytes, plasma, diaphragm and liver following blood-transfusion was found. These data show that soman is able to release from erythrocytes and inhibit cholinesterase activities not only in vitro but also in vivo although the significant inhibition of cholinesterase activities by soman was only observed in the peripheral compartment.

scholarly journals Latest Trends in Electrochemical Sensors for Neurotransmitters: A Review

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2037 ◽  
Author(s):  
Tavakolian-Ardakani ◽  
Hosu ◽  
Cristea ◽  
Mazloum-Ardakani ◽  
Marrazza
Keyword(s):  
Electrochemical Sensors ◽  
Ex Vivo ◽  
Analytical Techniques ◽  
Substantial Improvement ◽  
Robust Detection ◽  
Brain Functions ◽  
The Brain ◽  
Made In

Neurotransmitters are endogenous chemical messengers which play an important role in many of the brain functions, abnormal levels being correlated with physical, psychotic and neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's disease. Therefore, their sensitive and robust detection is of great clinical significance. Electrochemical methods have been intensively used in the last decades for neurotransmitter detection, outclassing more complicated analytical techniques such as conventional spectrophotometry, chromatography, fluorescence, flow injection, and capillary electrophoresis. In this manuscript, the most successful and promising electrochemical enzyme-free and enzymatic sensors for neurotransmitter detection are reviewed. Focusing on the activity of worldwide researchers mainly during the last ten years (2010–2019), without pretending to be exhaustive, we present an overview of the progress made in sensing strategies during this time. Particular emphasis is placed on nanostructured-based sensors, which show a substantial improvement of the analytical performances. This review also examines the progress made in biosensors for neurotransmitter measurements in vitro, in vivo and ex vivo.

PDGF receptors in the rat CNS: during late neurogenesis, PDGF alpha-receptor expression appears to be restricted to glial cells of the oligodendrocyte lineage

Development ◽  
1992 ◽  
Vol 115 (2) ◽  
pp. 535-551 ◽  
Author(s):  
N.P. Pringle ◽  
H.S. Mudhar ◽  
E.J. Collarini ◽  
W.D. Richardson
Keyword(s):  
Glial Cells ◽  
Receptor Expression ◽  
Binding Studies ◽  
Temporal And Spatial Distribution ◽  
Inner Limiting Membrane ◽  
Factor Alpha ◽  
The Brain

Using in situ hybridization, we have visualized cells in the rat central nervous system (CNS) that contain mRNA encoding the platelet-derived growth factor alpha receptor (PDGF-alpha R). After embryonic day 16 (E16), PDGF-alpha R mRNA appears to be expressed by a subset of glial cells, but not by neurons. The temporal and spatial distribution of PDGF-alpha R+ cells, together with 125I-PDGF binding studies on subsets of glial cells in vitro, suggests that PDGF-alpha R may be expressed predominantly, or exclusively, by cells of the oligodendrocyte-type-2 astrocyte (O-2A) lineage. This conclusion is supported by the fact that the numbers of PDGF-alpha R+ cells in developing and adult optic nerves correlate well with independent estimates of the number of O-2A progenitor cells in the nerve at equivalent ages. Small numbers of PDGF-alpha R+ cells are present in the brain at E16, at which time they are found outside the subventricular germinal zones, suggesting that these cells do not express PDGF-alpha R until after, or shortly before they start to migrate away from the subventricular layer towards their final destinations. Reduced numbers of PDGF-alpha R+ cells persist in the adult CNS. PDGF-alpha R is also expressed strongly in the meningeal membranes and choroid plexus, and in the inner limiting membrane of the retina.

Dissecting the regional diversity of glial cells by applying -omic technologies

e-Neuroforum ◽  
2015 ◽  
Vol 21 (3) ◽  
Author(s):  
Daniela C. Dieterich ◽  
Moritz J. Rossner
Keyword(s):  
Glial Cells ◽  
Brain Function ◽  
Recent Progress ◽  
Higher Order ◽  
Cell Populations ◽  
Cellular Activity ◽  
Regional Diversity ◽  
Brain Functions ◽  
Exploratory Approach ◽  
The Brain

AbstractNeuronal as well as glial cells contribute to higher order brain functions. Many observations show that neurons and glial cells are not only physically highly intermingled but are physiologically tightly connected and mutually depend at various levels on each other. Moreover, macroglia classes like astrocytes, NG2 cells and oligodendrocytes are not at all homogenous cell populations but do possess a markedly heterogeneity in various aspects similar to neurons. The diversity of differences in morphology, functionality and, cellular activity has been acknowledged recently and will be integrated into a concept of brain function that pictures a neural rather than a puristical neuronal world. With the recent progress in “omic” technologies, an unbiased and exploratory approach toward an enhanced understanding of glial heterogeneity has become possible. Here, we provide an overview on current technical transcriptomic and proteomic approaches used to dissect glial heterogeneity of the brain.

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