scholarly journals Generation of CSF1-Independent Ramified Microglia-Like Cells from Leptomeninges In Vitro

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Junya Tanaka ◽  
Hisaaki Takahashi ◽  
Hajime Yano ◽  
Hiroshi Nakanishi
Keyword(s):  
Growth Factor Receptor ◽  
Large Cell ◽  
Brain Parenchyma ◽  
Cell Aggregates ◽  
Primary Microglia ◽  
Mixed Glial Culture ◽  
Brain Surface ◽  
Del Rio ◽  
The Brain

Although del Río-Hortega originally reported that leptomeningeal cells are the source of ramified microglia in the developing brain, recent views do not seem to pay much attention to this notion. In this study, in vitro experiments were conducted to determine whether leptomeninges generate ramified microglia. The leptomeninges of neonatal rats containing Iba1+ macrophages were peeled off the brain surface. Leptomeningeal macrophages strongly expressed CD68 and CD163, but microglia in the brain parenchyma did not. Leptomeningeal macrophages expressed epidermal growth factor receptor (EGFR) as revealed by RT-PCR and immunohistochemical staining. Cells obtained from the peeled-off leptomeninges were cultured in a serum-free medium containing EGF, resulting in the formation of large cell aggregates in which many proliferating macrophages were present. In contrast, colony-stimulating factor 1 (CSF1) did not enhance the generation of Iba1+ cells from the leptomeningeal culture. The cell aggregates generated ramified Iba1+ cells in the presence of serum, which express CD68 and CD163 at much lower levels than primary microglia isolated from a mixed glial culture. Therefore, the leptomeningeal-derived cells resembled parenchymal microglia better than primary microglia. This study suggests that microglial progenitors expressing EGFR reside in the leptomeninges and that there is a population of microglia-like cells that grow independently of CSF1.

scholarly journals Vascular Dysfunction Induced by Mercury Exposure

2019 ◽  
Vol 20 (10) ◽  
pp. 2435 ◽  
Author(s):  
Tetsuya Takahashi ◽  
Takayoshi Shimohata
Keyword(s):  
Oxidative Stress ◽  
Vascular Dysfunction ◽  
Brain Parenchyma ◽  
Transport Systems ◽  
Mehg Exposure ◽  
In Vivo Models ◽  
The Central Nervous System ◽  
The Brain

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.

scholarly journals Pathological potential of astroglia

2008 ◽  
pp. S101-S110
Author(s):  
A Chvátal ◽  
M Anděrová ◽  
H Neprašová ◽  
I Prajerová ◽  
J Benešová ◽  
...  
Keyword(s):  
Glial Cells ◽  
Brain Parenchyma ◽  
Brain Diseases ◽  
Brain Pathology ◽  
Pathological Conditions ◽  
Recent Developments ◽  
Neurological Defect ◽  
Del Rio ◽  
The Brain ◽  
Brain Homeostasis

The pathological potential of glial cells was recognized already by Rudolf Virchow, Santiago Ramon y Cajal and Pio Del Rio-Ortega. Many functions and roles performed by astroglia in the healthy brain determine their involvement in brain diseases; as indeed any kind of brain insult does affect astrocytes, and their performance in pathological conditions, to a very large extent, determines the survival of the brain parenchyma, the degree of damage and neurological defect. Astrocytes being in general responsible for overall brain homeostasis are involved in virtually every form of brain pathology. Here we provide an overview of recent developments in identifying the role and mechanisms of the pathological potential of astroglia.

scholarly journals Development of Optically-Controlled “Living Electrodes” with Long-Projecting Axon Tracts for a Synaptic Brain-Machine Interface

2018 ◽  
Author(s):  
Dayo O. Adewole ◽  
Laura A. Struzyna ◽  
James P. Harris ◽  
Ashley D. Nemes ◽  
Justin C. Burrell ◽  
...  
Keyword(s):  
Brain Activity ◽  
Optical Recording ◽  
Neural Interfaces ◽  
New Class ◽  
Brain Surface ◽  
Long Term Performance ◽  
Term Performance ◽  
The Brain

AbstractAchievements in intracortical neural interfaces are compromised by limitations in specificity and long-term performance. A biological intermediary between devices and the brain may offer improved specificity and longevity through natural synaptic integration with deep neural circuitry, while being accessible on the brain surface for optical read-out/control. Accordingly, we have developed the first “living electrodes” comprised of implantable axonal tracts protected within soft hydrogel cylinders for the biologically-mediated monitoring/modulation of brain activity. Here we demonstrate the controlled fabrication, rapid axonal outgrowth, reproducible cytoarchitecture, and simultaneous optical stimulation and recording of neuronal activity within these engineered constructs in vitro. We also present their transplantation, survival, integration, and optical recording in rat cortex in vivo as a proof-of-concept for this neural interface paradigm. The creation and functional validation of these preformed, axon-based “living electrodes” is a critical step towards developing a new class of biohybrid neural interfaces to probe and modulate native circuitry.

scholarly journals In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

2016 ◽  
Vol 36 (5) ◽  
pp. 862-890 ◽  
Author(s):  
Hans C Helms ◽  
N Joan Abbott ◽  
Malgorzata Burek ◽  
Romeo Cecchelli ◽  
Pierre-Olivier Couraud ◽  
...  
Keyword(s):  
Cell Culture ◽  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Brain Parenchyma ◽  
Brain Barrier ◽  
Blood Brain ◽  
Culture Models ◽  
Cell Culture Models ◽  
The Brain

The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug transport to the brain and studies of endothelial cell biology and pathophysiology. In this review, we aim to give an overview of established in vitro blood–brain barrier models with a focus on their validation regarding a set of well-established blood–brain barrier characteristics. As an ideal cell culture model of the blood–brain barrier is yet to be developed, we also aim to give an overview of the advantages and drawbacks of the different models described.

scholarly journals A proline insertion-deletion in the spike glycoprotein fusion peptide of mouse hepatitis virus strongly alters neuropathology

2019 ◽  
Vol 294 (20) ◽  
pp. 8064-8087 ◽  
Author(s):  
Manmeet Singh ◽  
Abhinoy Kishore ◽  
Dibyajyoti Maity ◽  
Punnepalli Sunanda ◽  
Bankala Krishnarjuna ◽  
...  
Keyword(s):  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Brain Parenchyma ◽  
Fusion Peptides ◽  
Spike Glycoprotein ◽  
Fusion Event ◽  
Viral Spread ◽  
Secondary Amino ◽  
The Brain

Fusion peptides (FPs) in spike proteins are key players mediating early events in cell-to-cell fusion, vital for intercellular viral spread. A proline residue located at the central FP region has often been suggested to have a distinctive role in this fusion event. The spike glycoprotein from strain RSA59 (PP) of mouse hepatitis virus (MHV) contains two central, consecutive prolines in the FP. Here, we report that deletion of one of these proline residues, resulting in RSA59 (P), significantly affected neural cell syncytia formation and viral titers postinfection in vitro. Transcranial inoculation of C57Bl/6 mice with RSA59 (PP) or RSA59 (P) yielded similar degrees of necrotizing hepatitis and meningitis, but only RSA59 (PP) produced widespread encephalitis that extended deeply into the brain parenchyma. By day 6 postinfection, both virus variants were mostly cleared from the brain. Interestingly, inoculation with the RSA59 (P)–carrying MHV significantly reduced demyelination at the chronic stage. We also found that the presence of two consecutive prolines in FP promotes a more ordered, compact, and rigid structure in the spike protein. These effects on FP structure were due to proline's unique stereochemical properties intrinsic to its secondary amino acid structure, revealed by molecular dynamics and NMR experiments. We therefore propose that the differences in the severity of encephalitis and demyelination between RSA59 (PP) and RSA59 (P) arise from the presence or absence, respectively, of the two consecutive prolines in FP. Our studies define a structural determinant of MHV entry in the brain parenchyma important for altered neuropathogenesis.

scholarly journals New optical method for analyzing cortical blood flow heterogeneity in small animals: validation of the method

2000 ◽  
Vol 279 (3) ◽  
pp. H1291-H1298 ◽  
Author(s):  
Istvan Schiszler ◽  
Minoru Tomita ◽  
Yasuo Fukuuchi ◽  
Norio Tanahashi ◽  
Koji Inoue
Keyword(s):  
Blood Flow ◽  
Mean Transit Time ◽  
Region Of Interest ◽  
Brain Parenchyma ◽  
Sprague Dawley ◽  
Doppler Flowmetry ◽  
Cranial Window ◽  
Brain Surface ◽  
Fine Glass ◽  
The Brain

In pentobarbital-anesthetized male Sprague-Dawley rats, a small cranial window was trephined, and the cortex was transilluminated with a fine glass fiber inserted into the brain parenchyma. The light intensity at the surface area of 2 × 2 mm was recorded during intracarotid injection of 25 μl of carbon black (CB) solution. The region of interest (ROI) was divided into a 50 × 50 matrix, and the mean transit time of CB transport was calculated in each matrix element. We found rapid transits of CB along the microvasculature, with considerable heterogeneity in the avascular area, and heterogeneous efficiency in autoregulatory capacity in the ROI during hypotension. The method was validated by comparison with laser-Doppler flowmetry. The average mean difference was 0.03 ± 0.05%. Five percent CO2 inhalation increased the flow by 85%, but heterogeneously. We concluded that the technique is exclusively sensitive to indicator transits in a very small area on the brain surface with potential usefulness in detecting regional heterogeneity in blood flow.

scholarly journals Expression of functional CD40 antigen on Reed-Sternberg cells and Hodgkin's disease cell lines

Blood ◽  
1995 ◽  
Vol 85 (3) ◽  
pp. 780-789 ◽  
Author(s):  
A Carbone ◽  
A Gloghini ◽  
V Gattei ◽  
D Aldinucci ◽  
M Degan ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Lines ◽  
Hodgkin's Disease ◽  
Hodgkin’S Disease ◽  
Growth Factor Receptor ◽  
Large Cell ◽  
Distinct Pattern ◽  
Histologic Subtype ◽  
Hodgkin's Lymphomas

CD40 is a member of the nerve growth factor receptor family, showing a significant homology to the Hodgkin's disease (HD)-associated antigen CD30 and is capable of transduce growth signals in a number of cell types. A series of 312 lymphoma samples, including 139 cases of HD, 32 cases of CD30+ anaplastic large cell (ALC) lymphomas, 141 cases of other non-Hodgkin's lymphomas (NHLs), and a panel of HD- or NHL-derived cell lines, were evaluated for CD40 expression by immunostaining of paraffin embedded sections, cell smears and flow cytometry. CD40 was strongly expressed with a highly distinct pattern of staining on Reed- Sternberg (RS) cells and variants in 100% (139/139) of HD cases, irrespective of their antigenic phenotype (T, B, non T-non B) and histologic subtype of HD. Conversely, CD40 was immunodetected on only one third (12/32; 37%) of ALC lymphoma cases and on 105 of 127 B-cell NHLs. The relative cell density of CD40 on HD cell lines (L-428, KM-H2, HDLM-2) as assessed by flow cytometry was significantly higher than on all other lymphoma cells analyzed. Engagement of CD40 by its soluble ligand (CD40L) enhanced both clonogenic capacity and colony cell survival of HD cell lines. Such effect was potentiated by interleukin-9 costimulation in KM-H2 cells. Finally, we have shown that in vitro rosetting of activated CD4+ T cells to HD cells (L-428) is mediated in part by the CD40/CD40L adhesion pathway. Our data indicate that CD40 is a useful antigen for immunodetection and identification of tumor cells in all subtypes of HD, and suggest that it may play a role in the regulation of RS cell expansion and the contact-dependent interactions of these cells with cytokine-producing T lymphocytes.

scholarly journals Application of fluorescent dextrans to the brain surface under constant pressure reveals AQP4-independent solute uptake

2021 ◽  
Vol 153 (8) ◽  
Author(s):  
Alex J. Smith ◽  
Gokhan Akdemir ◽  
Meetu Wadhwa ◽  
Dan Song ◽  
Alan S. Verkman
Keyword(s):  
Constant Pressure ◽  
Water Channel ◽  
Solute Concentration ◽  
External Pressure ◽  
Brain Parenchyma ◽  
Interstitial Space ◽  
Brain Surface ◽  
Solute Uptake ◽  
The Brain

Extracellular solutes in the central nervous system are exchanged between the interstitial fluid, the perivascular compartment, and the cerebrospinal fluid (CSF). The “glymphatic” mechanism proposes that the astrocyte water channel aquaporin-4 (AQP4) is a major determinant of solute transport between the CSF and the interstitial space; however, this is controversial in part because of wide variance in experimental data on interstitial uptake of cisternally injected solutes. Here, we investigated the determinants of solute uptake in brain parenchyma following cisternal injection and reexamined the role of AQP4 using a novel constant-pressure method. In mice, increased cisternal injection rate, which modestly increased intracranial pressure, remarkably increased solute dispersion in the subarachnoid space and uptake in the cortical perivascular compartment. To investigate the role of AQP4 in the absence of confounding variations in pressure and CSF solute concentration over time and space, solutes were applied directly onto the brain surface after durotomy under constant external pressure. Pressure elevation increased solute penetration into the perivascular compartment but had little effect on parenchymal solute uptake. Solute penetration and uptake did not differ significantly between wild-type and AQP4 knockout mice. Our results offer an explanation for the variability in cisternal injection studies and indicate AQP4-independent solute transfer from the CSF to the interstitial space in mouse brain.

scholarly journals The CCL2-CCR2 astrocyte-cancer cell axis in tumor extravasation at the brain

2021 ◽  
Vol 7 (26) ◽  
pp. eabg8139
Author(s):  
Cynthia Hajal ◽  
Yoojin Shin ◽  
Leanne Li ◽  
Jean Carlos Serrano ◽  
Tyler Jacks ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cancer Cell ◽  
Three Dimensional ◽  
Brain Parenchyma ◽  
Cell Axis ◽  
Chemokine Ligand ◽  
Chemokine Ligand 2 ◽  
The Brain

Although brain metastases are common in cancer patients, little is known about the mechanisms of cancer extravasation across the blood-brain barrier (BBB), a key step in the metastatic cascade that regulates the entry of cancer cells into the brain parenchyma. Here, we show, in a three-dimensional in vitro BBB microvascular model, that astrocytes promote cancer cell transmigration via their secretion of C-C motif chemokine ligand 2 (CCL2). We found that this chemokine, produced primarily by astrocytes, promoted the chemotaxis and chemokinesis of cancer cells via their C-C chemokine receptor type 2 (CCR2), with no notable changes in vascular permeability. These findings were validated in vivo, where CCR2-deficient cancer cells exhibited significantly reduced rates of arrest and transmigration in mouse brain capillaries. Our results reveal that the CCL2-CCR2 astrocyte-cancer cell axis plays a fundamental role in extravasation and, consequently, metastasis to the brain.

The betaine-GABA transporter (BGT1, slc6a12) is predominantly expressed in the liver and at lower levels in the kidneys and at the brain surface

2012 ◽  
Vol 302 (3) ◽  
pp. F316-F328 ◽  
Author(s):  
Y. Zhou ◽  
S. Holmseth ◽  
R. Hua ◽  
A. C. Lehre ◽  
A. M. Olofsson ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Renal Medulla ◽  
Brain Parenchyma ◽  
Ependymal Cells ◽  
Main Role ◽  
Mrna Levels ◽  
Physiological Importance ◽  
Brain Surface ◽  
Negative Controls ◽  
The Brain

The Na+- and Cl−-dependent GABA-betaine transporter (BGT1) has received attention mostly as a protector against osmolarity changes in the kidney and as a potential controller of the neurotransmitter GABA in the brain. Nevertheless, the cellular distribution of BGT1, and its physiological importance, is not fully understood. Here we have quantified mRNA levels using TaqMan real-time PCR, produced a number of BGT1 antibodies, and used these to study BGT1 distribution in mice. BGT1 (protein and mRNA) is predominantly expressed in the liver (sinusoidal hepatocyte plasma membranes) and not in the endothelium. BGT1 is also present in the renal medulla, where it localizes to the basolateral membranes of collecting ducts (particularly at the papilla tip) and the thick ascending limbs of Henle. There is some BGT1 in the leptomeninges, but brain parenchyma, brain blood vessels, ependymal cells, the renal cortex, and the intestine are virtually BGT1 deficient in 1- to 3-mo-old mice. Labeling specificity was assured by processing tissue from BGT1-deficient littermates in parallel as negative controls. Addition of 2.5% sodium chloride to the drinking water for 48 h induced a two- to threefold upregulation of BGT1, tonicity-responsive enhancer binding protein, and sodium- myo-inositol cotransporter 1 (slc5a3) in the renal medulla, but not in the brain and barely in the liver. BGT1-deficient and wild-type mice appeared to tolerate the salt treatment equally well, possibly because betaine is one of several osmolytes. In conclusion, this study suggests that BGT1 plays its main role in the liver, thereby complementing other betaine-transporting carrier proteins (e.g., slc6a20) that are predominantly expressed in the small intestine or kidney rather than the liver.

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