Differentiating neurons activate transcription of the brain lipid-binding protein gene in radial glia through a novel regulatory element

Development ◽  
1995 ◽  
Vol 121 (6) ◽  
pp. 1719-1730 ◽  
Author(s):  
L. Feng ◽  
N. Heintz
Keyword(s):  
Glial Cells ◽  
Radial Glia ◽  
Lipid Binding ◽  
Radial Glial Cell ◽  
Specific Element ◽  
Radial Glial ◽  
And Migration ◽  
The Brain

Formation and maintenance of a radial glial scaffold is fundamental for development of the vertebrate central nervous system. In mammals, radial glia arise in the neuroepithelium immediately prior to differentiation and migration of neurons away from the ventricular zones, and they are maintained until neuronal migration subsides. We have previously shown that expression of the brain lipid-binding protein (BLBP) in radial glia throughout the developing CNS is strictly correlated with the differentiation and migration of neurons upon these cells, and that BLBP function is required to maintain differentiation of primary cerebellar glial cells in vitro (Feng, L., Hatten, M. E. and Heintz, N. (1994). Neuron 12, 895–908). In this study, we demonstrate that BLBP transcription in vivo involves multiple regulatory elements, and that the dynamic temporal and spatial pattern of BLBP expression in radial and Bergmann glial cells throughout the developing CNS is programmed by a single radial glial cell-specific element (RGE). Furthermore, we demonstrate that BLBP expression in primary cerebellar glial cells requires coculture with differentiating neurons, and that this induction is regulated by the radial glia-specific element. The fact that transcription of BLBP in response to neurons in vitro and its dynamic regulation in radial glia throughout the CNS in vivo are both controlled by the RGE provides the first direct evidence supporting a role for differentiating neurons in the epigenetic regulation of radial glial cell function in vivo.

scholarly journals BSCI-12. Inhibition of melanoma brain metastasis by targeting miR-146a

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii3-iii3
Author(s):  
Jiwei Wang ◽  
Emma Rigg ◽  
Taral R Lunavat ◽  
Wenjing Zhou ◽  
Zichao Feng ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Western Blots ◽  
Cell Growth And Migration ◽  
Human Astrocytes ◽  
And Migration ◽  
The Brain

Abstract Background Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released by the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. Materials and Methods miRNAs from exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. Results miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146a in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. Conclusions MiR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

P16.08 Inhibition of melanoma brain metastasis by targeting miR-146a

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii57-ii57
Author(s):  
J Wang ◽  
E K Rigg ◽  
T R Lunavat ◽  
W Zhou ◽  
Z Feng ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Western Blots ◽  
Cell Growth And Migration ◽  
Human Astrocytes ◽  
And Migration ◽  
The Brain

Abstract BACKGROUND Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released from the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. MATERIAL AND METHODS miRNAs in exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. RESULTS miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146 in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. CONCLUSION miR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

scholarly journals Inhibited maturation of astrocytes caused by maternal n-3 polyunsaturated fatty acid intake deficiency hinders the development of brain glial cells in neonatal rats

2021 ◽  
pp. 1-26
Author(s):  
Tatsuro Yamamoto ◽  
Ayako Yamamoto ◽  
Hiroki Tanabe ◽  
Naomichi Nishimura
Keyword(s):  
Glial Cells ◽  
Lipid Binding ◽  
Brain Cell ◽  
Neonatal Rats ◽  
Pufa Intake ◽  
Radial Glial Cells ◽  
Somatosensory Cortices ◽  
Radial Glial ◽  
The Impact ◽  
The Brain

Abstract The brain is rich in long chain polyunsaturated fatty acids (PUFAs), which play an essential role in its development and functions. Here we examined the impact of maternal n-3 PUFA intake deficiency during gestation and lactation on the development of glial cells in the pup’s developing cerebral cortex. In addition, using myelination as indicator and the anti-myelin basic protein (MBP) as measurement to establish the relationship between the number of glial fibrillary acidic protein (GFAP)-positive cells and the development of oligodendrocytes, we determined the myelination state of the somatosensory cortex at day 14 postnatal. Rat dams were fed either a control (Cont) or an n-3 PUFA-deficient (Def) diet for 60 days (acclimatisation :14 days; gestation: 21 days; lactation:21 days). Pups lactated from dams throughout the experiment. The distribution pattern of astrocytes in pups on day 7 postnatal was immunohistochemically analysed using GFAP and brain lipid binding protein (BLBP) as markers for mature astrocytes and astrocyte-specific radial glial cells, respectively. It was observed that, when compared with Cont pups, GFAP-positive cells decreased, BLBP-positive cells increased and myelinated structures were sparser in the somatosensory cortices of Def pups. In the open field test on day 21 postnatal, behavioural parameters did not differ between groups. Our results indicated that inhibited maturation of astrocytes caused by maternal n-3 PUFA deficiency hindered the development of brain glial cells of neonatal rats and hence, maternal n-3 PUFA intake during the gestation and lactation periods may have been crucial for the brain cell composition of pups.

scholarly journals Transcriptional priming as a conserved mechanism of lineage diversification in the developing mouse and human neocortex

2020 ◽  
Vol 6 (45) ◽  
pp. eabd2068
Author(s):  
Zhen Li ◽  
William A. Tyler ◽  
Ella Zeldich ◽  
Gabriel Santpere Baró ◽  
Mayumi Okamoto ◽  
...  
Keyword(s):  
Glial Cells ◽  
Radial Glia ◽  
Radial Glial Cells ◽  
Human Neocortex ◽  
Intermediate Progenitors ◽  
Cell Diversity ◽  
Radial Glial ◽  
The Rich ◽  
Lineage Diversification

How the rich variety of neurons in the nervous system arises from neural stem cells is not well understood. Using single-cell RNA-sequencing and in vivo confirmation, we uncover previously unrecognized neural stem and progenitor cell diversity within the fetal mouse and human neocortex, including multiple types of radial glia and intermediate progenitors. We also observed that transcriptional priming underlies the diversification of a subset of ventricular radial glial cells in both species; genetic fate mapping confirms that the primed radial glial cells generate specific types of basal progenitors and neurons. The different precursor lineages therefore diversify streams of cell production in the developing murine and human neocortex. These data show that transcriptional priming is likely a conserved mechanism of mammalian neural precursor lineage specialization.

scholarly journals MiR-375 attenuates injury of cerebral ischemia/reperfusion via targetting Ctgf

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Jianying Ou ◽  
Li Kou ◽  
Lingyan Liang ◽  
Chaogang Tang
Keyword(s):  
Ischemia Reperfusion ◽  
Protective Effects ◽  
Significant Protection ◽  
Stroke Models ◽  
And Migration ◽  
The Brain ◽  
Insight Into ◽  
Proliferation And Migration

Ischemic stroke is the leading cause of disability and deaths worldwide. MiRNAs have been shown to play an important role in development and pathogenesis of the nervous system. However, the precise function and mechanism of miRNAs are not fully understood in the brain injury induced by ischemia/reperfusion (I/R). Herein, our study showed that miR-375 expression was significantly down-regulated in the rat I/R brain. With the in vivo and in vitro I/R stroke models, we found that miR-375 mimic provides significant protection from injury to cerebral I/R, which is reflected by reduced infarct volumes and cell apoptosis, and increased proliferation and migration of PC12 cells. Mechanistically, our findings showed that miR-375 binds to 3′-UTR region of Ctgf mRNA, subsequently leading to the decreased expression of Ctgf in the I/R brain. Furthermore, we showed that miR-375/Ctgf-mediated protective effects are associated with p21/PI3K/Akt signaling pathways. Our findings thus provide a new insight into the mechanism of cerebral I/R injury and pave a potential new way for the therapy of cerebral I/R injury.

Glial Cells as Progenitors and Stem Cells: New Roles in the Healthy and Diseased Brain

2014 ◽  
Vol 94 (3) ◽  
pp. 709-737 ◽  
Author(s):  
Leda Dimou ◽  
Magdalena Götz
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Glial Cells ◽  
Mammalian Brain ◽  
Radial Glial Cells ◽  
Glial Progenitors ◽  
Stem And Progenitor Cells ◽  
Radial Glial

The diverse functions of glial cells prompt the question to which extent specific subtypes may be devoted to a specific function. We discuss this by reviewing one of the most recently discovered roles of glial cells, their function as neural stem cells (NSCs) and progenitor cells. First we give an overview of glial stem and progenitor cells during development; these are the radial glial cells that act as NSCs and other glial progenitors, highlighting the distinction between the lineage of cells in vivo and their potential when exposed to a different environment, e.g., in vitro. We then proceed to the adult stage and discuss the glial cells that continue to act as NSCs across vertebrates and others that are more lineage-restricted, such as the adult NG2-glia, the most frequent progenitor type in the adult mammalian brain, that remain within the oligodendrocyte lineage. Upon certain injury conditions, a distinct subset of quiescent astrocytes reactivates proliferation and a larger potential, clearly demonstrating the concept of heterogeneity with distinct subtypes of, e.g., astrocytes or NG2-glia performing rather different roles after brain injury. These new insights not only highlight the importance of glial cells for brain repair but also their great potential in various aspects of regeneration.

scholarly journals Local Translation Across Neural Development: A Focus on Radial Glial Cells, Axons, and Synaptogenesis

2021 ◽  
Vol 14 ◽  
Author(s):  
Manasi Agrawal ◽  
Kristy Welshhans
Keyword(s):  
Glial Cells ◽  
Neural Development ◽  
Mrna Localization ◽  
Local Translation ◽  
Radial Glial Cells ◽  
Functional Changes ◽  
Axon Development ◽  
Radial Glial

In the past two decades, significant progress has been made in our understanding of mRNA localization and translation at distal sites in axons and dendrites. The existing literature shows that local translation is regulated in a temporally and spatially restricted manner and is critical throughout embryonic and post-embryonic life. Here, recent key findings about mRNA localization and local translation across the various stages of neural development, including neurogenesis, axon development, and synaptogenesis, are reviewed. In the early stages of development, mRNAs are localized and locally translated in the endfeet of radial glial cells, but much is still unexplored about their functional significance. Recent in vitro and in vivo studies have provided new information about the specific mechanisms regulating local translation during axon development, including growth cone guidance and axon branching. Later in development, localization and translation of mRNAs help mediate the major structural and functional changes that occur in the axon during synaptogenesis. Clinically, changes in local translation across all stages of neural development have important implications for understanding the etiology of several neurological disorders. Herein, local translation and mechanisms regulating this process across developmental stages are compared and discussed in the context of function and dysfunction.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

Targeting Matrix Metalloproteinases in Atherosclerosis and Cardiovascular Dysfunction

2019 ◽  
Vol 70 (2) ◽  
pp. 718-720
Author(s):  
Lucia Corina Dima-Cozma ◽  
Sebastian Cozma ◽  
Delia Hinganu ◽  
Cristina Mihaela Ghiciuc ◽  
Florin Mitu
Keyword(s):  
Smooth Muscle ◽  
Matrix Metalloproteinases ◽  
Cholesterol Synthesis ◽  
Balloon Dilation ◽  
Aortic Aneurysms ◽  
Arterial Lesions ◽  
Smooth Muscle Cell Migration ◽  
And Migration

Matrix metalloproteinases (MMPs) are the primary mediators of extracellular remodeling and their properties are useful in diagnostic evaluation and treatment. They are zinc-dependent proteases. MMPs have been involved in the mechanisms of atherosclerosis in various arterial areas, ischemic heart disease and myocardial infarction, atrial fibrillation and aortic aneurysms. Recently, MMP9 has been implicated in dyslipidemia and cholesterol synthesis by the liver. Increased MMP expression and activity has been associated with neointimal arterial lesions and migration of smooth muscle cells after arterial balloon dilation, while MMP inhibition decreases smooth muscle cell migration in vivo and in vitro.

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