scholarly journals A genome-wide view of the de-differentiation of central nervous system endothelial cells in culture

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Mark F Sabbagh ◽  
Jeremy Nathans

Vascular endothelial cells (ECs) derived from the central nervous system (CNS) variably lose their unique barrier properties during in vitro culture, hindering the development of robust assays for blood-brain barrier (BBB) function, including drug permeability and extrusion assays. In previous work (Sabbagh et al., 2018) we characterized transcriptional and accessible chromatin landscapes of acutely isolated mouse CNS ECs. In this report, we compare transcriptional and accessible chromatin landscapes of acutely isolated mouse CNS ECs versus mouse CNS ECs in short-term in vitro culture. We observe that standard culture conditions are associated with a rapid and selective loss of BBB transcripts and chromatin features, as well as a greatly reduced level of beta-catenin signaling. Interestingly, forced expression of a stabilized derivative of beta-catenin, which in vivo leads to a partial conversion of non-BBB CNS ECs to a BBB-like state, has little or no effect on gene expression or chromatin accessibility in vitro.

2020 ◽  
Author(s):  
Daniela C. Ivan ◽  
Sabrina Walthert ◽  
Giuseppe Locatelli

ABSTRACTThe central nervous system (CNS) parenchyma is enclosed by anatomical interfaces including multilayered meninges, the blood-brain barrier (BBB), the choroid plexuses within ventricles and the glia limitans. These border areas hold distinct functional specializations which control the trafficking of monocyte-derived cells toward the CNS parenchyma, altogether maintaining CNS homeostasis. By crossing activated endothelial, epithelial and glial borders, circulating leukocytes gain however access to the CNS parenchyma in several inflammatory diseases including multiple sclerosis.Studies in animal models of neuroinflammation have helped describing the phenotypic specifications of these invading monocyte-derived cells, able to exert detrimental or beneficial functions depending on the local environment. In this context, in vivo visualization of iNOS+ pro-inflammatory and arginase-1+ anti-inflammatory macrophages has recently revealed that these distinct cell phenotypes are highly compartmentalized by CNS borders. While arginase-1+ macrophages densely populate the leptomeninges, iNOS+ macrophages rather accumulate in perivascular spaces and at the pia mater-CNS parenchymal interface.How and where these macrophages acquire their functional commitment, and whether differentially-activated monocyte-derived cells infiltrate the CNS through distinct gateways, remains however unclear.In this study, we have investigated the interaction of monocyte-derived macrophages with endothelial (BBB) and epithelial (choroid plexus) barriers of the CNS, both in vitro and in vivo. By using primary mouse brain microvascular endothelial cells as in vitro model of the BBB, we observed that, compared to unpolarized primary macrophages, adhesion of functionally-committed macrophages to endothelial cells was drastically reduced, literally abrogating their diapedesis across the BBB. Conversely, when interacting with an activated choroid plexus epithelium, both pro- and anti-inflammatory macrophages displayed substantial adhesive and migratory properties. Accordingly, in vivo analysis of choroid plexuses revealed increased macrophage trafficking and a scattered presence of polarized cells upon induction of anti-CNS inflammation.Altogether, we show that acquisition of distinct macrophage polarizations significantly alters the adhesive and migratory properties of these cells in a barrier-specific fashion. While monocytes trafficking at the level of the BBB seem to acquire their signature phenotype only following diapedesis, other anatomical interfaces can be the entry site for functionally activated monocyte-derived cells. Our study highlights the choroid plexus as a key access gateway for macrophages during neuroinflammation, and its stroma as a potential priming site for their functional polarization.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Marion Clé ◽  
Orianne Constant ◽  
Jonathan Barthelemy ◽  
Caroline Desmetz ◽  
Marie France Martin ◽  
...  

Abstract Background Usutu virus (USUV) is an emerging neurotropic arthropod-borne virus recently involved in massive die offs of wild birds predominantly reported in Europe. Although primarily asymptomatic or presenting mild clinical signs, humans infected by USUV can develop neuroinvasive pathologies (including encephalitis and meningoencephalitis). Similar to other flaviviruses, such as West Nile virus, USUV is capable of reaching the central nervous system. However, the neuropathogenesis of USUV is still poorly understood, and the virulence of the specific USUV lineages is currently unknown. One of the major complexities of the study of USUV pathogenesis is the presence of a great diversity of lineages circulating at the same time and in the same location. Methods The aim of this work was to determine the neurovirulence of isolates from the six main lineages circulating in Europe using mouse model and several neuronal cell lines (neurons, microglia, pericytes, brain endothelial cells, astrocytes, and in vitro Blood-Brain Barrier model). Results Our results indicate that all strains are neurotropic but have different virulence profiles. The Europe 2 strain, previously described as being involved in several clinical cases, induced the shortest survival time and highest mortality in vivo and appeared to be more virulent and persistent in microglial, astrocytes, and brain endothelial cells, while also inducing an atypical cytopathic effect. Moreover, an amino acid substitution (D3425E) was specifically identified in the RNA-dependent RNA polymerase domain of the NS5 protein of this lineage. Conclusions Altogether, these data show a broad neurotropism for USUV in the central nervous system with lineage-dependent virulence. Our results will help to better understand the biological and epidemiological diversity of USUV infection.


2007 ◽  
Vol 98 (10) ◽  
pp. 823-830 ◽  
Author(s):  
Erica Behling-Kelly ◽  
Kwang Kim ◽  
Charles Czuprynski

SummaryThrombotic meningoencephalitis (TME) is a neurological condition in cattle characterized by fibrinopurulent meningitis with hemorrhage, abscess formation and thrombotic vasculitis throughout the central nervous system. The etiologic agent of TME is Haemophilus somnus, a gram-negative pleomorphic coccobacillus. Although the pathogenesis of TME is not well understood, the propensity of H. somnus to cause vasculitis and intravascular thrombosis suggests a critical role for the interactions between the bacteria and endothelial cells in inciting the disease. The goal of this study was to determine if H. somnus elicits an inflammatory and procoagulative response in bovine brain micro- vascular endothelial cells (BBEC) in vitro. We demonstrate that BBEC exposed to H. somnus secrete significant levels of the proinflammatory and procoagulative cytokines TNF-α and IL-1β. BBEC treated with H. somnus also display increased levels of IL-6 mRNA,another cytokine associated with coagulopathy in vivo. H. somnus-treated BBEC exhibited increased procoagulant activity and tissue factor expression and activity,along with a decreased ability to activate protein C and decreased expression of thrombomodulin mRNA. These changes would be expected to promote thrombus formation in vessels of the CNS, and potentially contribute to the pathogenesis of TME.


1946 ◽  
Vol 84 (4) ◽  
pp. 277-292 ◽  
Author(s):  
S. Edward Sulkin ◽  
Christine Zarafonetis ◽  
Andres Goth

Anesthesia with diethyl ether significantly alters the course and outcome of experimental infections with the equine encephalomyelitis virus (Eastern or Western type) or with the St. Louis encephalitis virus. No comparable effect is observed in experimental infections produced with rabies or poliomyelitis (Lansing) viruses. The neurotropic virus infections altered by ether anesthesia are those caused by viruses which are destroyed in vitro by this anesthetic, and those infections not affected by ether anesthesia are caused by viruses which apparently are not destroyed by ether in vitro. Another striking difference between these two groups of viruses is their pathogenesis in the animal host; those which are inhibited in vivo by ether anesthesia tend to infect cells of the cortex, basal ganglia, and only occasionally the cervical region of the cord. On the other hand, those which are not inhibited in vivo by ether anesthesia tend to involve cells of the lower central nervous system and in the case of rabies, peripheral nerves. This difference is of considerable importance in view of the fact that anesthetics affect cells of the lower central nervous system only in very high concentrations. It is obvious from the complexity of the problem that no clear-cut statement can be made at this point as to the mechanism of the observed effect of ether anesthesia in reducing the mortality rate in certain of the experimental neurotropic virus infections. Important possibilities include a direct specific effect of diethyl ether upon the virus and a less direct effect of the anesthetic upon the virus through its alteration of the metabolism of the host cell.


2016 ◽  
Vol 38 (3) ◽  
pp. 859-870 ◽  
Author(s):  
Mingfeng He ◽  
Hongquan Dong ◽  
Yahui Huang ◽  
Shunmei Lu ◽  
Shu Zhang ◽  
...  

Background/Aims: Microglia are an essential player in central nervous system inflammation. Recent studies have demonstrated that the astrocytic chemokine, CCL2, is associated with microglial activation in vivo. However, CCL2-induced microglial activation has not yet been studied in vitro. The purpose of the current study was to understand the role of astrocyte-derived CCL2 in microglial activation and to elucidate the underlying mechanism(s). Methods: Primary astrocytes were pre-treated with CCL2 siRNA and stimulated with TNF-α. The culture medium (CM) was collected and added to cultures of microglia, which were incubated with and without CCR2 inhibitor. Microglial cells were analyzed by quantitative RT-PCR to determine whether they polarized to the M1 or M2 state. Microglial migratory ability was assessed by transwell migration assay. Results: TNF-α stimulated the release of CCL2 from astrocytes, even if the culture media containing TNF-α was replaced with fresh media after 3 h. CM from TNF-α-stimulated astrocytes successfully induced microglial activation, which was ascertained by increased activation of M1 and enhanced migration ability. In contrast, CM from astrocytes pretreated with CCL2 siRNA showed no effect on microglial activation, compared to controls. Additionally, microglia pre-treated with RS102895, a CCR2 inhibitor, were resistant to activation by CM from TNF-α-stimulated astrocytes. Conclusion: This study demonstrates that the CCL2/CCR2 pathway of astrocyte-induced microglial activation is associated with M1 polarization and enhanced migration ability, indicating that this pathway could be a useful target to ameliorate inflammation in the central nervous system.


1996 ◽  
Vol 316 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Ralf BIRKENHÄGER ◽  
Bernard SCHNEPPE ◽  
Wolfgang RÖCKL ◽  
Jörg WILTING ◽  
Herbert A. WEICH ◽  
...  

Vascular endothilial growth factor (VEGF) and placenta growth factor (PIGF) are members of a dimeric-growth-factor family with angiogenic properties. VEGF is a highly potent and specific mitogen for endothelial cells, playing a vital role in angiogenesis in vivo. The role of PIGF is less clear. We expressed the monomeric splice forms VEGF-165, VEGF-121, PIGF-1 and PlGF-2 as unfused genes in Escherichia coli using the pCYTEXP expression system. In vitro dimerization experiments revealed that both homo- and hetero-dimers can be formed from these monomeric proteins. The dimers were tested for their ability to promote capillary growth in vivo and stimulate DNA synthesis in cultured human vascular endothelial cells. Heterodimers comprising different VEGF splice forms, or combinations of VEGF/PlGF splice forms, showed mitogenic activity. The results demonstrate that four different heterodimeric growth factors are likely to have as yet uncharacterized functions in vivo.


2018 ◽  
Vol 5 (4) ◽  
pp. 96 ◽  
Author(s):  
Anders Bailey ◽  
Amreena Suri ◽  
Pauline Chou ◽  
Tatiana Pundy ◽  
Samantha Gadd ◽  
...  

Neuroblastoma (NB) is the most common extracranial solid tumor in pediatrics, with rare occurrences of primary and metastatic tumors in the central nervous system (CNS). We previously reported the overexpression of the polo-like kinase 4 (PLK4) in embryonal brain tumors. PLK4 has also been found to be overexpressed in a variety of peripheral adult tumors and recently in peripheral NB. Here, we investigated PLK4 expression in NBs of the CNS (CNS-NB) and validated our findings by performing a multi-platform transcriptomic meta-analysis using publicly available data. We evaluated the PLK4 expression by quantitative real-time PCR (qRT-PCR) on the CNS-NB samples and compared the relative expression levels among other embryonal and non-embryonal brain tumors. The relative PLK4 expression levels of the NB samples were found to be significantly higher than the non-embryonal brain tumors (p-value < 0.0001 in both our samples and in public databases). Here, we expand upon our previous work that detected PLK4 overexpression in pediatric embryonal tumors to include CNS-NB. As we previously reported, inhibiting PLK4 in embryonal tumors led to decreased tumor cell proliferation, survival, invasion and migration in vitro and tumor growth in vivo, and therefore PLK4 may be a potential new therapeutic approach to CNS-NB.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ni Zhang ◽  
Lichong Zhu ◽  
Qiuhong Ouyang ◽  
Saisai Yue ◽  
Yichun Huang ◽  
...  

Polymyxin B (PMB) exert bactericidal effects on the cell wall of Gram-negative bacteria, leading to changes in the permeability of the cytoplasmic membrane and resulting in cell death, which is sensitive to the multi-resistant Gram-negative bacteria. However, the severe toxicity and adverse side effects largely hamper the clinical application of PMB. Although the molecular pathology of PMB neurotoxicity has been adequately studied at the cellular and molecular level. However, the impact of PMB on the physiological states of central nervous system in vivo may be quite different from that in vitro, which need to be further studied. Therefore, in the current study, the biocompatible ultra-uniform Fe3O4 nanoparticles were employed for noninvasively in vivo visualizing the potential impairment of PMB to the central nervous system. Systematic studies clearly reveal that the prepared Fe3O4 nanoparticles can serve as an appropriate magnetic resonance contrast agent with high transverse relaxivity and outstanding biosafety, which thus enables the following in vivo susceptibility-weighted imaging (SWI) studies on the PMB-treated mice models. As a result, it is first found that the blood-brain barrier (BBB) of mice may be impaired by successive PMB administration, displaying by the discrete punctate SWI signals distributed asymmetrically across brain regions in brain parenchyma. This result may pave a noninvasive approach for in-depth studies of PMB medication strategy, monitoring the BBB changes during PMB treatment, and even assessing the risk after PMB successive medication in multidrug-resistant Gram-negative bacterial infected patients from the perspective of medical imaging.


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