scholarly journals Role of the imprinted allele of the p57Kip2 gene in mouse neocortical development

2019 ◽  
Author(s):  
Yui Imaizumi ◽  
Shohei Furutachi ◽  
Tomoyuki Watanabe ◽  
Hiroaki Miya ◽  
Daichi Kawaguchi ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Brain Size ◽  
Paternal Allele ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Conditional Deletion ◽  
Neocortical Development ◽  
Neural Stem Progenitor Cells ◽  
The Central Nervous System ◽  
And Function

AbstractImprinted genes are expressed from only one allele in a parent of origin–specific manner. The cyclin-dependent kinase inhibitor p57Kip2 (p57) is encoded by an imprinted gene, with the paternal allele being silenced. The possible expression and function of the paternal allele of p57 have remained little studied, however. We now show that the paternal allele of the p57 gene is expressed at a low level in the developing mouse neocortex. Surprisingly, the central nervous system-specific conditional deletion of the paternal allele (pat cKO) at the p57 locus resulted in a marked reduction in brain size. Furthermore, pat cKO gradually reduced the number of neural stem-progenitor cells (NPCs) during neocortical development, and thus reduced the number of upper-layer neurons, which were derived from late-stage NPCs. Our results thus show that the paternal allele of the p57 locus plays a key role in maintenance of NPCs during neocortical development.

Endocannabinoid system in the neurodevelopment of GABAergic interneurons: implications for neurological and psychiatric disorders

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chang-geng Song ◽  
Xin Kang ◽  
Fang Yang ◽  
Wan-qing Du ◽  
Jia-jia Zhang ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Endocannabinoid System ◽  
Autism Spectrum ◽  
Network Activity ◽  
Inhibitory Neurons ◽  
Gabaergic Interneurons ◽  
Neural Stem Progenitor Cells ◽  
The Central Nervous System ◽  
Interneuron Development

Abstract In mature mammalian brains, the endocannabinoid system (ECS) plays an important role in the regulation of synaptic plasticity and the functioning of neural networks. Besides, the ECS also contributes to the neurodevelopment of the central nervous system. Due to the increase in the medical and recreational use of cannabis, it is inevitable and essential to elaborate the roles of the ECS on neurodevelopment. GABAergic interneurons represent a group of inhibitory neurons that are vital in controlling neural network activity. However, the role of the ECS in the neurodevelopment of GABAergic interneurons remains to be fully elucidated. In this review, we provide a brief introduction of the ECS and interneuron diversity. We focus on the process of interneuron development and the role of ECS in the modulation of interneuron development, from the expansion of the neural stem/progenitor cells to the migration, specification and maturation of interneurons. We further discuss the potential implications of the ECS and interneurons in the pathogenesis of neurological and psychiatric disorders, including epilepsy, schizophrenia, major depressive disorder and autism spectrum disorder.

p21−/− Mice Exhibit Spontaneous Articular Cartilage Regeneration Post-Injury

Cartilage ◽  
2019 ◽  
pp. 194760351987634 ◽  
Author(s):  
Christina L. Jablonski ◽  
Bryce A. Besler ◽  
Jahaan Ali ◽  
Roman J. Krawetz
Keyword(s):  
Articular Cartilage ◽  
Kinase Inhibitor ◽  
Cartilage Regeneration ◽  
Cartilage Thickness ◽  
Cartilage Defects ◽  
Post Injury ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Cartilage Healing ◽  
Articular Cartilage Regeneration

Objective Recent studies have implicated the cyclin dependent kinase inhibitor, p21, in enhanced tissue regeneration observed in MRL/MpJ “super-healer” mice. Specifically, p21 is downregulated in MRL cells and similar ear hole closure to MRL mice has been observed in p21−/− mice. However, the direct implications of p21 deletion in endogenous articular cartilage regeneration remain unknown. In this study, we investigated the role of p21 deletion in the ability of mice to heal full-thickness cartilage defects (FTCDs). Design C57BL/6 and p21−/− ( Cdkn1atm1Tyj) mice were subjected to FTCD and assessment of cartilage healing was performed at 1 hour, 3 days, 1 week, 2 weeks, and 4 weeks post-FTCD using a 14-point histological scoring system. X-ray microscopy was used to quantify cartilage healing parameters (e.g., cartilage thickness, surface area/volume) between C57BL/6 and p21−/− mice. Results Absence of p21 resulted in increased spontaneous articular cartilage regeneration by 3 days post-FTCD. Furthermore, p21−/− mice presented with increased cartilage thickness at 1 and 2 weeks post-FTCD compared with uninjured controls, returning to baseline by 4 weeks post-FTCD. Conclusions We report that p21−/− mice display enhanced articular cartilage regeneration post-FTCD compared with C57BL/6 mice. Furthermore, cartilage thickness was increased in p21−/− mice at 1 week post-FTCD compared with uninjured p21−/− mice and C57BL/6 mice.

scholarly journals The Role of Adrenoceptors in the Retina

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2594
Author(s):  
Yue Ruan ◽  
Tobias Böhmer ◽  
Subao Jiang ◽  
Adrian Gericke
Keyword(s):  
Visual Information ◽  
Vision Loss ◽  
Retinal Diseases ◽  
System A ◽  
The Central Nervous System ◽  
The Individual ◽  
And Function ◽  
The Brain

The retina is a part of the central nervous system, a thin multilayer with neuronal lamination, responsible for detecting, preprocessing, and sending visual information to the brain. Many retinal diseases are characterized by hemodynamic perturbations and neurodegeneration leading to vision loss and reduced quality of life. Since catecholamines and respective bindings sites have been characterized in the retina, we systematically reviewed the literature with regard to retinal expression, distribution and function of alpha1 (α1)-, alpha2 (α2)-, and beta (β)-adrenoceptors (ARs). Moreover, we discuss the role of the individual adrenoceptors as targets for the treatment of retinal diseases.

scholarly journals A sart1 Zebrafish Mutant Results in Developmental Defects in the Central Nervous System

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2340
Author(s):  
Hannah E. Henson ◽  
Michael R. Taylor
Keyword(s):  
Central Nervous System ◽  
Cell Death ◽  
Nervous System ◽  
Developmental Defects ◽  
Whole Exome ◽  
The Central Nervous System ◽  
And Function ◽  
Upregulated Genes ◽  
The Brain

The spliceosome consists of accessory proteins and small nuclear ribonucleoproteins (snRNPs) that remove introns from RNA. As splicing defects are associated with degenerative conditions, a better understanding of spliceosome formation and function is essential. We provide insight into the role of a spliceosome protein U4/U6.U5 tri-snRNP-associated protein 1, or Squamous cell carcinoma antigen recognized by T-cells (Sart1). Sart1 recruits the U4.U6/U5 tri-snRNP complex to nuclear RNA. The complex then associates with U1 and U2 snRNPs to form the spliceosome. A forward genetic screen identifying defects in choroid plexus development and whole-exome sequencing (WES) identified a point mutation in exon 12 of sart1 in Danio rerio (zebrafish). This mutation caused an up-regulation of sart1. Using RNA-Seq analysis, we identified additional upregulated genes, including those involved in apoptosis. We also observed increased activated caspase 3 in the brain and eye and down-regulation of vision-related genes. Although splicing occurs in numerous cells types, sart1 expression in zebrafish was restricted to the brain. By identifying sart1 expression in the brain and cell death within the central nervous system (CNS), we provide additional insights into the role of sart1 in specific tissues. We also characterized sart1’s involvement in cell death and vision-related pathways.

scholarly journals Histamine H2 receptor radioligands: triumphs and challenges

2021 ◽  
Author(s):  
Steffen Pockes ◽  
Katharina Tropmann
Keyword(s):  
Receptor Expression ◽  
In Vitro Assays ◽  
Histamine H2 Receptor ◽  
Drug Candidates ◽  
Carbon 14 ◽  
The Central Nervous System ◽  
And Function ◽  
Role And Function

Since the discovery of the histamine H2 receptor (H2R), radioligands were among the most powerful tools to investigate its role and function. Initially, radiolabeling was used to investigate human and rodent tissues regarding their receptor expression. Later, radioligands gained increasing significance as pharmacological tools in in vitro assays. Although tritium-labeling was mainly used for this purpose, labeling with carbon-14 is preferred for metabolic studies of drug candidates. After the more-or-less successful application of numerous labeled H2R antagonists, the recent development of the G protein-biased radioligand [3H]UR-KAT479 represents another step forward to elucidate the widely unknown role of the H2R in the central nervous system through future studies.

scholarly journals Role of Macrophages and Microglia in Zebrafish Regeneration

2020 ◽  
Vol 21 (13) ◽  
pp. 4768 ◽  
Author(s):  
Susanna R. Var ◽  
Christine A. Byrd-Jacobs
Keyword(s):  
Nervous System ◽  
Immune Cells ◽  
Immune Cell ◽  
Innate Immune ◽  
Inflammatory Processes ◽  
The Central Nervous System ◽  
And Function ◽  
High Degree ◽  
Human Nerve

Currently, there is no treatment for recovery of human nerve function after damage to the central nervous system (CNS), and there are limited regenerative capabilities in the peripheral nervous system. Since fish are known for their regenerative abilities, understanding how these species modulate inflammatory processes following injury has potential translational importance for recovery from damage and disease. Many diseases and injuries involve the activation of innate immune cells to clear damaged cells. The resident immune cells of the CNS are microglia, the primary cells that respond to infection and injury, and their peripheral counterparts, macrophages. These cells serve as key modulators of development and plasticity and have been shown to be important in the repair and regeneration of structure and function after injury. Zebrafish are an emerging model for studying macrophages in regeneration after injury and microglia in neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease. These fish possess a high degree of neuroanatomical, neurochemical, and emotional/social behavioral resemblance with humans, serving as an ideal simulator for many pathologies. This review explores literature on macrophage and microglial involvement in facilitating regeneration. Understanding innate immune cell behavior following damage may help to develop novel methods for treating toxic and chronic inflammatory processes that are seen in trauma and disease.

scholarly journals MiR-9 and the Midbrain-Hindbrain Boundary: A Showcase for the Limited Functional Conservation and Regulatory Complexity of MicroRNAs

2020 ◽  
Vol 8 ◽  
Author(s):  
A. Alwin Prem Anand ◽  
Gonzalo Alvarez-Bolado ◽  
Andrea Wizenmann
Keyword(s):  
Neuronal Development ◽  
Brain Size ◽  
Regulatory System ◽  
Large Degree ◽  
Regulate Gene Expression ◽  
Functional Conservation ◽  
Regulatory Complexity ◽  
Species Specific ◽  
And Function

MicroRNAs regulate gene expression at post-transcriptional levels. Some of them appear to regulate brain development and are involved in neurodevelopmental disorders. This has led to the suggestion that the role of microRNAs in neuronal development and function may be more central than previously appreciated. Here, we review the data about miR-9 function to depict the subtlety, complexity, flexibility and limited functional conservation of this essential developmental regulatory system. On this basis we propose that species-specific actions of miR-9 could underlie to a large degree species differences in brain size, shape and function.

scholarly journals Activation and Role of Astrocytes in Ischemic Stroke

2021 ◽  
Vol 15 ◽  
Author(s):  
Xin-Ya Shen ◽  
Zhen-Kun Gao ◽  
Yu Han ◽  
Mei Yuan ◽  
Yi-Sha Guo ◽  
...  
Keyword(s):  
Nervous System ◽  
Ischemic Stroke ◽  
Protective Role ◽  
Reactive Astrocytes ◽  
High Morbidity ◽  
Temporal Expression ◽  
The Central Nervous System ◽  
Controversial Topic ◽  
And Function

Ischemic stroke refers to the disorder of blood supply of local brain tissue caused by various reasons. It has high morbidity and mortality worldwide. Astrocytes are the most abundant glial cells in the central nervous system (CNS). They are responsible for the homeostasis, nutrition, and protection of the CNS and play an essential role in many nervous system diseases’ physiological and pathological processes. After stroke injury, astrocytes are activated and play a protective role through the heterogeneous and gradual changes of their gene expression, morphology, proliferation, and function, that is, reactive astrocytes. However, the position of reactive astrocytes has always been a controversial topic. Many studies have shown that reactive astrocytes are a double-edged sword with both beneficial and harmful effects. It is worth noting that their different spatial and temporal expression determines astrocytes’ various functions. Here, we comprehensively review the different roles and mechanisms of astrocytes after ischemic stroke. In addition, the intracellular mechanism of astrocyte activation has also been involved. More importantly, due to the complex cascade reaction and action mechanism after ischemic stroke, the role of astrocytes is still difficult to define. Still, there is no doubt that astrocytes are one of the critical factors mediating the deterioration or improvement of ischemic stroke.

scholarly journals Astroglial Connexins in Neurodegenerative Diseases

2021 ◽  
Vol 14 ◽  
Author(s):  
Xiaomin Huang ◽  
Yixun Su ◽  
Nan Wang ◽  
Hui Li ◽  
Zhigang Li ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Neuronal Function ◽  
Gap Junction Channels ◽  
Normal Functions ◽  
Functional Remodeling ◽  
The Central Nervous System ◽  
Key Aspects ◽  
And Function ◽  
Lateral Sclerosis

Astrocytes play a crucial role in the maintenance of the normal functions of the Central Nervous System (CNS). During the pathogenesis of neurodegenerative diseases, astrocytes undergo morphological and functional remodeling, a process called reactive astrogliosis, in response to the insults to the CNS. One of the key aspects of the reactive astrocytes is the change in the expression and function of connexins. Connexins are channel proteins that highly expressed in astrocytes, forming gap junction channels and hemichannels, allowing diffusional trafficking of small molecules. Alterations of astrocytic connexin expression and function found in neurodegenerative diseases have been shown to affect the disease progression by changing neuronal function and survival. In this review, we will summarize the role of astroglial connexins in neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Also, we will discuss why targeting connexins can be a plausible therapeutic strategy to manage these neurodegenerative diseases.

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