New neurons in the adult brain: The role of sleep and consequences of sleep loss

The revelation of adult brain exhibiting neurogenesis has established that the brain possesses great plasticity and that neurons could be spawned in the neurogenic zones where hippocampal adult neurogenesis attributes to learning and memory processes. With strong implications in brain functional homeostasis, aging and cognition, various aspects of adult neurogenesis reveal exuberant mechanistic associations thereby further aiding in facilitating the therapeutic approaches regarding the development of neurodegenerative processes in Alzheimer’s Disease (AD). Impaired neurogenesis has been significantly evident in AD with compromised hippocampal function and cognitive deficits. Melatonin the pineal indolamine augments neurogenesis and has been linked to AD development as its levels are compromised with disease progression. Here, in this review, we discuss and appraise the mechanisms via which melatonin regulates neurogenesis in pathophysiological conditions which would unravel the molecular basis in such conditions and its role in endogenous brain repair. Also, its components as key regulators of neural stem and progenitor cell proliferation and differentiation in the embryonic and adult brain would aid in accentuating the therapeutic implications of this indoleamine in line of prevention and treatment of AD.

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Early Consumption of Cannabinoids: From Adult Neurogenesis to Behavior

International Journal of Molecular Sciences ◽

10.3390/ijms22147450 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7450

Author(s):

Citlalli Netzahualcoyotzi ◽

Luis Miguel Rodríguez-Serrano ◽

María Elena Chávez-Hernández ◽

Mario Humberto Buenrostro-Jáuregui

Keyword(s):

Young Adulthood ◽

Adult Neurogenesis ◽

Critical Period ◽

Consumption Rate ◽

Behavioral Outcomes ◽

Endocannabinoid System ◽

Illegal Drug ◽

Adult Brain ◽

As Stress

The endocannabinoid system (ECS) is a crucial modulatory system in which interest has been increasing, particularly regarding the regulation of behavior and neuroplasticity. The adolescent–young adulthood phase of development comprises a critical period in the maturation of the nervous system and the ECS. Neurogenesis occurs in discrete regions of the adult brain, and this process is linked to the modulation of some behaviors. Since marijuana (cannabis) is the most consumed illegal drug globally and the highest consumption rate is observed during adolescence, it is of particular importance to understand the effects of ECS modulation in these early stages of adulthood. Thus, in this article, we sought to summarize recent evidence demonstrating the role of the ECS and exogenous cannabinoid consumption in the adolescent–young adulthood period; elucidate the effects of exogenous cannabinoid consumption on adult neurogenesis; and describe some essential and adaptive behaviors, such as stress, anxiety, learning, and memory. The data summarized in this work highlight the relevance of maintaining balance in the endocannabinoid modulatory system in the early and adult stages of life. Any ECS disturbance may induce significant modifications in the genesis of new neurons and may consequently modify behavioral outcomes.

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AIF3 splicing switch triggers neurodegeneration

Molecular Neurodegeneration ◽

10.1186/s13024-021-00442-7 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Shuiqiao Liu ◽

Mi Zhou ◽

Zhi Ruan ◽

Yanan Wang ◽

Calvin Chang ◽

...

Keyword(s):

Cell Death ◽

Neurodegenerative Diseases ◽

Mitochondrial Dysfunction ◽

Nuclear Translocation ◽

Chromatin Condensation ◽

Neuronal Cell ◽

Adult Brain ◽

Postmortem Brain ◽

Mitochondrial Functions

Abstract Background Apoptosis-inducing factor (AIF), as a mitochondrial flavoprotein, plays a fundamental role in mitochondrial bioenergetics that is critical for cell survival and also mediates caspase-independent cell death once it is released from mitochondria and translocated to the nucleus under ischemic stroke or neurodegenerative diseases. Although alternative splicing regulation of AIF has been implicated, it remains unknown which AIF splicing isoform will be induced under pathological conditions and how it impacts mitochondrial functions and neurodegeneration in adult brain. Methods AIF splicing induction in brain was determined by multiple approaches including 5′ RACE, Sanger sequencing, splicing-specific PCR assay and bottom-up proteomic analysis. The role of AIF splicing in mitochondria and neurodegeneration was determined by its biochemical properties, cell death analysis, morphological and functional alterations and animal behavior. Three animal models, including loss-of-function harlequin model, gain-of-function AIF3 knockin model and conditional inducible AIF splicing model established using either Cre-loxp recombination or CRISPR/Cas9 techniques, were applied to explore underlying mechanisms of AIF splicing-induced neurodegeneration. Results We identified a nature splicing AIF isoform lacking exons 2 and 3 named as AIF3. AIF3 was undetectable under physiological conditions but its expression was increased in mouse and human postmortem brain after stroke. AIF3 splicing in mouse brain caused enlarged ventricles and severe neurodegeneration in the forebrain regions. These AIF3 splicing mice died 2–4 months after birth. AIF3 splicing-triggered neurodegeneration involves both mitochondrial dysfunction and AIF3 nuclear translocation. We showed that AIF3 inhibited NADH oxidase activity, ATP production, oxygen consumption, and mitochondrial biogenesis. In addition, expression of AIF3 significantly increased chromatin condensation and nuclear shrinkage leading to neuronal cell death. However, loss-of-AIF alone in harlequin or gain-of-AIF3 alone in AIF3 knockin mice did not cause robust neurodegeneration as that observed in AIF3 splicing mice. Conclusions We identified AIF3 as a disease-inducible isoform and established AIF3 splicing mouse model. The molecular mechanism underlying AIF3 splicing-induced neurodegeneration involves mitochondrial dysfunction and AIF3 nuclear translocation resulting from the synergistic effect of loss-of-AIF and gain-of-AIF3. Our study provides a valuable tool to understand the role of AIF3 splicing in brain and a potential therapeutic target to prevent/delay the progress of neurodegenerative diseases.

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Loss of Non-Apoptotic Role of Caspase-3 in the PINK1 Mouse Model of Parkinson’s Disease

International Journal of Molecular Sciences ◽

10.3390/ijms20143407 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3407 ◽

Cited By ~ 2

Author(s):

Paola Imbriani ◽

Annalisa Tassone ◽

Maria Meringolo ◽

Giulia Ponterio ◽

Graziella Madeo ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Synaptic Plasticity ◽

Mouse Model ◽

Caspase 3 ◽

Cysteine Proteases ◽

Synaptic Function ◽

Adult Brain ◽

Striatal Slices

Caspases are a family of conserved cysteine proteases that play key roles in multiple cellular processes, including programmed cell death and inflammation. Recent evidence shows that caspases are also involved in crucial non-apoptotic functions, such as dendrite development, axon pruning, and synaptic plasticity mechanisms underlying learning and memory processes. The activated form of caspase-3, which is known to trigger widespread damage and degeneration, can also modulate synaptic function in the adult brain. Thus, in the present study, we tested the hypothesis that caspase-3 modulates synaptic plasticity at corticostriatal synapses in the phosphatase and tensin homolog (PTEN) induced kinase 1 (PINK1) mouse model of Parkinson’s disease (PD). Loss of PINK1 has been previously associated with an impairment of corticostriatal long-term depression (LTD), rescued by amphetamine-induced dopamine release. Here, we show that caspase-3 activity, measured after LTD induction, is significantly decreased in the PINK1 knockout model compared with wild-type mice. Accordingly, pretreatment of striatal slices with the caspase-3 activator α-(Trichloromethyl)-4-pyridineethanol (PETCM) rescues a physiological LTD in PINK1 knockout mice. Furthermore, the inhibition of caspase-3 prevents the amphetamine-induced rescue of LTD in the same model. Our data support a hormesis-based double role of caspase-3; when massively activated, it induces apoptosis, while at lower level of activation, it modulates physiological phenomena, like the expression of corticostriatal LTD. Exploring the non-apoptotic activation of caspase-3 may contribute to clarify the mechanisms involved in synaptic failure in PD, as well as in view of new potential pharmacological targets.

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Retromer subunit, VPS29, regulates synaptic transmission and is required for endolysosomal function in the aging brain

eLife ◽

10.7554/elife.51977 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 4

Author(s):

Hui Ye ◽

Shamsideen A Ojelade ◽

David Li-Kroeger ◽

Zhongyuan Zuo ◽

Liping Wang ◽

...

Keyword(s):

Synaptic Transmission ◽

Protein Complex ◽

Adult Brain ◽

Aging Brain ◽

Gtpase Activating Protein ◽

Ultrastructural Evidence ◽

Aging Adults ◽

And Function ◽

Brain Homeostasis

Retromer, including Vps35, Vps26, and Vps29, is a protein complex responsible for recycling proteins within the endolysosomal pathway. Although implicated in both Parkinson’s and Alzheimer’s disease, our understanding of retromer function in the adult brain remains limited, in part because Vps35 and Vps26 are essential for development. In Drosophila, we find that Vps29 is dispensable for embryogenesis but required for retromer function in aging adults, including for synaptic transmission, survival, and locomotion. Unexpectedly, in Vps29 mutants, Vps35 and Vps26 proteins are normally expressed and associated, but retromer is mislocalized from neuropil to soma with the Rab7 GTPase. Further, Vps29 phenotypes are suppressed by reducing Rab7 or overexpressing the GTPase activating protein, TBC1D5. With aging, retromer insufficiency triggers progressive endolysosomal dysfunction, with ultrastructural evidence of impaired substrate clearance and lysosomal stress. Our results reveal the role of Vps29 in retromer localization and function, highlighting requirements for brain homeostasis in aging.

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Brain Tumors

Goodman's Neurosurgery Oral Board Review ◽

10.1093/med/9780190636937.003.0004 ◽

2016 ◽

pp. 11-24 ◽

Cited By ~ 1

Author(s):

Chikezie Eseonu ◽

Jordina Rincon-Torroella ◽

Alfredo Quiñones-Hinojosa

Keyword(s):

Brain Tumor ◽

Brain Tumors ◽

Demyelinating Disease ◽

Brain Lesion ◽

Pituitary Tumors ◽

Current Treatment ◽

Preoperative Care ◽

Adult Brain ◽

Surgical Approaches

Brain tumor cases make up a significant part of the neurosurgery Oral Board Exam. A multitude of brain tumors exist and can be intraaxial or extraaxial. When considering a differential diagnosis for a brain lesion, infection, hematomas, infarctions, thrombosed aneurysms, inflammation, and demyelinating disease must be considered in addition to tumors. Common adult brain tumors consist of gliomas, meningiomas, metastases, and pituitary tumors. Management of brain tumors consists of understanding preoperative care, indications for surgery, surgical approaches, interpretation of preoperative and postoperative imaging, intraoperative and postoperative complications, and the role of adjuvant therapy, including chemotherapy and radiotherapy. Reviewing these essential points for the most common brain tumor cases and mastering the current treatment recommendations for common tumors will also be helpful for the boards.

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TMIC-56. ROLE OF HUMAN BRAIN TUMOR STEM CELLS-DERIVED EXTRACELLULAR VESICLES ON THE PHENOTYPIC TRANSDIFFERENTIATION OF HUMAN NEURAL PROGENITOR CELLS

Neuro-Oncology ◽

10.1093/neuonc/noz175.1090 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi260-vi260

Author(s):

Natanael Zarco ◽

Emily Norton ◽

Montserrat Lara-Velazquez ◽

Anna Carrano ◽

Alfredo Quinones-Hinojosa ◽

...

Keyword(s):

Stem Cells ◽

Brain Tumor ◽

Tumor Microenvironment ◽

Extracellular Vesicles ◽

Primary Cultures ◽

Adult Brain ◽

Cell Subpopulation ◽

Tumor Stem Cells ◽

Brain Tumor Stem Cells

Abstract Glioblastoma (GBM) is the most aggressive of all the brain tumors with a median patient survival less than 15 months. Despite of surgical resection, radiotherapy, and chemotherapy, recurrence rate is almost 100%. A great percentage of GBM tumors (~60%) infiltrate and contact the ventricular-subventricular zone (V-SVZ). Interestingly, these tumors are the most aggressive, and invariably lead to higher distal recurrence rates, shorter time to tumor progression, and lower overall survival of the patient. The reason for this role of V-SVZ-proximity on the outcome of GBM patients is unknown. We suggest that a potential explanation is the interaction of GBM with the V-SVZ. This region is the largest neurogenic niche in the adult brain where neural stem cells (NSCs) give rise to newborn neuroblasts that migrate toward the olfactory bulb. In GBM there is a cell subpopulation called brain tumor stem cells (BTSCs) with NSCs-like characteristics, but with added potential for tumor initiation, recurrence and invasiveness. Tumor microenvironment plays an important role in migration and invasion process. In the present work, we used the total exosome isolation kit to purify Extracellular Vesicles (EVs) from human primary cultures of BTSCs. We determined that BTSCs-derived EVs contain specific information that is transfer to primary cultures of human Neural Progenitors Cells (NPCs) modulating their proliferation rate, cell viability, and migration. In addition, we identify that NPCs taken up BTSCs-derived EVs and significantly increase the expression levels of stemness-related genes such as Nestin, Nanog, and Sox2, suggesting that a phenotypic transdifferentiation is being carry out. These results support our hypothesis that GBM modulate the tumor microenvironment close to the V-SVZ by releasing EVs that target cellular components in this region and promote their phenotypic transformation, highlighting that NPCs biology changes in the context of tumor environment.

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The Role of Mast Cells in Stroke

Cells ◽

10.3390/cells8050437 ◽

2019 ◽

Vol 8 (5) ◽

pp. 437 ◽

Cited By ~ 8

Author(s):

Edoardo Parrella ◽

Vanessa Porrini ◽

Marina Benarese ◽

Marina Pizzi

Keyword(s):

Central Nervous System ◽

Immune Response ◽

Nervous System ◽

Mast Cells ◽

Brain Edema ◽

Hemorrhagic Stroke ◽

Inflammatory Responses ◽

Adult Brain ◽

The Central Nervous System

Mast cells (MCs) are densely granulated perivascular resident cells of hematopoietic origin. Through the release of preformed mediators stored in their granules and newly synthesized molecules, they are able to initiate, modulate, and prolong the immune response upon activation. Their presence in the central nervous system (CNS) has been documented for more than a century. Over the years, MCs have been associated with various neuroinflammatory conditions of CNS, including stroke. They can exacerbate CNS damage in models of ischemic and hemorrhagic stroke by amplifying the inflammatory responses and promoting brain–blood barrier disruption, brain edema, extravasation, and hemorrhage. Here, we review the role of these peculiar cells in the pathophysiology of stroke, in both immature and adult brain. Further, we discuss the role of MCs as potential targets for the treatment of stroke and the compounds potentially active as MCs modulators.

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