scholarly journals Low-Level Endothelial TRAIL-Receptor Expression Obstructs the CNS-Delivery of Angiopep-2 Functionalised TRAIL-Receptor Agonists for the Treatment of Glioblastoma

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7582
Author(s):  
Nivetha Krishna Krishna Moorthy ◽  
Oliver Seifert ◽  
Stephan Eisler ◽  
Sara Weirich ◽  
Roland E. Kontermann ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Fusion Proteins ◽  
Receptor Expression ◽  
Brain Barrier ◽  
Trail Receptor ◽  
Binding Studies ◽  
Receptor Agonists ◽  
Blood Brain ◽  
The Central Nervous System

Glioblastoma (GBM) is the most malignant and aggressive form of glioma and is associated with a poor survival rate. Latest generation Tumour Necrosis Factor Related Apoptosis-Inducing Ligand (TRAIL)-based therapeutics potently induce apoptosis in cancer cells, including GBM cells, by binding to death receptors. However, the blood–brain barrier (BBB) is a major obstacle for these biologics to enter the central nervous system (CNS). We therefore investigated if antibody-based fusion proteins that combine hexavalent TRAIL and angiopep-2 (ANG2) moieties can be developed, with ANG2 promoting receptor-mediated transcytosis (RMT) across the BBB. We demonstrate that these fusion proteins retain the potent apoptosis induction of hexavalent TRAIL-receptor agonists. Importantly, blood–brain barrier cells instead remained highly resistant to this fusion protein. Binding studies indicated that ANG2 is active in these constructs but that TRAIL-ANG2 fusion proteins bind preferentially to BBB endothelial cells via the TRAIL moiety. Consequently, transport studies indicated that TRAIL-ANG2 fusion proteins can, in principle, be shuttled across BBB endothelial cells, but that low TRAIL receptor expression on BBB endothelial cells interferes with efficient transport. Our work therefore demonstrates that TRAIL-ANG2 fusion proteins remain highly potent in inducing apoptosis, but that therapeutic avenues will require combinatorial strategies, such as TRAIL-R masking, to achieve effective CNS transport.

scholarly journals Crossing the Blood-Brain Barrier by Neuroinvasive Pathogens

2018 ◽  
Vol 62 (1) ◽  
pp. 44-51
Author(s):  
Z. Tkáčová ◽  
E. Káňová ◽  
I. Jiménez-Munguía ◽  
Ľ. Čomor ◽  
I. Širochmanová ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Endothelial Cells ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Brain Cells ◽  
Blood Brain ◽  
The Central Nervous System ◽  
Vector Borne ◽  
Host Brain

Abstract The penetration of the blood-brain barrier (BBB) and invasion of the central nervous system (CNS) are important steps for all neuroinvasive pathogens. All of the ways of pathogens passing through the BBB are still unclear. Among known pathways, pathogen traversal can occur paracellularly, transcellularly or using a “Trojan horse” mechanism. The first step of translocation across the BBB is the interactions of the pathogen’s ligands with the receptors of the host brain cells. Lyme disease, the most common vector-borne disease in the temperate zones of Europe and North America, are caused by Borreliella species (former Borrelia burgdorferi sensu lato) that affects the peripheral and the CNS. In this review, we have presented various pathogen interactions with endothelial cells, which allow the disruption of the BBB so that the pathogens can pass across the BBB.

scholarly journals Size-selective loosening of the blood-brain barrier in claudin-5–deficient mice

2003 ◽  
Vol 161 (3) ◽  
pp. 653-660 ◽  
Author(s):  
Takehiro Nitta ◽  
Masaki Hata ◽  
Shimpei Gotoh ◽  
Yoshiteru Seo ◽  
Hiroyuki Sasaki ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Endothelial Cells ◽  
Nervous System ◽  
Blood Vessels ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Blood Brain ◽  
The Central Nervous System ◽  
Deficient Mice

Tight junctions are well-developed between adjacent endothelial cells of blood vessels in the central nervous system, and play a central role in establishing the blood-brain barrier (BBB). Claudin-5 is a major cell adhesion molecule of tight junctions in brain endothelial cells. To examine its possible involvement in the BBB, claudin-5–deficient mice were generated. In the brains of these mice, the development and morphology of blood vessels were not altered, showing no bleeding or edema. However, tracer experiments and magnetic resonance imaging revealed that in these mice, the BBB against small molecules (<800 D), but not larger molecules, was selectively affected. This unexpected finding (i.e., the size-selective loosening of the BBB) not only provides new insight into the basic molecular physiology of BBB but also opens a new way to deliver potential drugs across the BBB into the central nervous system.

scholarly journals Function of Connexins in the Interaction between Glial and Vascular Cells in the Central Nervous System and Related Neurological Diseases

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yinan Zhao ◽  
Yanguo Xin ◽  
Zhiyi He ◽  
Wenyu Hu
Keyword(s):  
Central Nervous System ◽  
Endothelial Cells ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
Neurological Diseases ◽  
Brain Barrier ◽  
Blood Brain ◽  
Capillary Endothelial Cells ◽  
The Central Nervous System ◽  
Junction Proteins

Neuronal signaling together with synapse activity in the central nervous system requires a precisely regulated microenvironment. Recently, the blood-brain barrier is considered as a “neuro-glia-vascular unit,” a structural and functional compound composed of capillary endothelial cells, glial cells, pericytes, and neurons, which plays a pivotal role in maintaining the balance of the microenvironment in and out of the brain. Tight junctions and adherens junctions, which function as barriers of the blood-brain barrier, are two well-known kinds in the endothelial cell junctions. In this review, we focus on the less-concerned contribution of gap junction proteins, connexins in blood-brain barrier integrity under physio-/pathology conditions. In the neuro-glia-vascular unit, connexins are expressed in the capillary endothelial cells and prominent in astrocyte endfeet around and associated with maturation and function of the blood-brain barrier through a unique signaling pathway and an interaction with tight junction proteins. Connexin hemichannels and connexin gap junction channels contribute to the physiological or pathological progress of the blood-brain barrier; in addition, the interaction with other cell-cell-adhesive proteins is also associated with the maintenance of the blood-brain barrier. Lastly, we explore the connexins and connexin channels involved in the blood-brain barrier in neurological diseases and any programme for drug discovery or delivery to target or avoid the blood-brain barrier.

scholarly journals Membrane transporter proteins: a challenge for CNS drug development

2006 ◽  
Vol 8 (3) ◽  
pp. 311-321 ◽  
Keyword(s):  
Central Nervous System ◽  
Endothelial Cells ◽  
Nervous System ◽  
Choroid Plexus ◽  
Blood Brain Barrier ◽  
Drug Transporters ◽  
Brain Barrier ◽  
Brain Capillary ◽  
Blood Brain ◽  
The Central Nervous System

Drug transporters are membrane proteins present in various tissues such as the lymphocytes, intestine, liver, kidney, testis, placenta, and central nervous system. These transporters play a significant role in drug absorption and distribution to organic systems, particularly if the organs are protected by blood-organ barriers, such as the blood-brain barrier or the maternal-fetal barrier. In contrast to neurotransmitters and receptor-coupled transporters or other modes of interneuronal transmission, drug transporters are not directly involved in specific neuronal functions, but provide global protection to the central nervous system. The lack of capillary fenestration, the low pinocytic activity and the tight junctions between brain capillary and choroid plexus endothelial cells represent further gatekeepers limiting the entrance of endogenous and exogenous compounds into the central nervous system. Drug transport is a result of the concerted action of efflux and influx pumps (transporters) located both in the basolateral and apical membranes of brain capillary and choroid plexus endothelial cells. By regulating efflux and influx of endogenous or exogenous substances, the blood-brain barrier and, to a lesser extent the blood-cerebrospinal barrier in the ventricles, represents the main interface between the central nervous system and the blood, i.e., the rest of the body. As drug distribution to organs is dependent on the affinity of a substrate for a specific transport system, membrane transporter proteins are increasingly recognized as a key determinant of drug disposition. Many drug transporters are members of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter superfamily or the solute-linked carrier (SLC) class. The multidrug resistance protein MDR1 (ABCB1), also called P-glycoprotein, the multidrug resistance-associated proteins MRP1 (ABCC1) and MRP2 (ABCC2), and the breast cancer-resistance protein BCRP (ABCG2) are ATP-dependent efflux transporters expressed in the blood-brain barrier They belong to the superfamily of ABC transporters, which export drugs from the intracellular to the extracellular milieu. Members of the SLC class of solute carriers include, for example, organic ion transporting peptides, organic cation transporters, and organic ion transporters. They are ATP-independent polypeptides principally expressed at the basolateral membrane of brain capillary and choroid plexus endothelial cells that also mediate drug transport through central nervous system barriers.

scholarly journals The Blood–Brain Barrier, Oxidative Stress, and Insulin Resistance

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1695
Author(s):  
William A. Banks ◽  
Elizabeth M. Rhea
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Insulin Signaling ◽  
Brain Barrier ◽  
Blood Brain ◽  
The Central Nervous System ◽  
The Impact ◽  
Peripheral Metabolism

The blood–brain barrier (BBB) is a network of specialized endothelial cells that regulates substrate entry into the central nervous system (CNS). Acting as the interface between the periphery and the CNS, the BBB must be equipped to defend against oxidative stress and other free radicals generated in the periphery to protect the CNS. There are unique features of brain endothelial cells that increase the susceptibility of these cells to oxidative stress. Insulin signaling can be impacted by varying levels of oxidative stress, with low levels of oxidative stress being necessary for signaling and higher levels being detrimental. Insulin must cross the BBB in order to access the CNS, levels of which are important in peripheral metabolism as well as cognition. Any alterations in BBB transport due to oxidative stress at the BBB could have downstream disease implications. In this review, we cover the interactions of oxidative stress at the BBB, how insulin signaling is related to oxidative stress, and the impact of the BBB in two diseases greatly affected by oxidative stress and insulin resistance: diabetes mellitus and Alzheimer’s disease.

scholarly journals Analysis of regional heterogeneities of the blood-brain barrier in humans and mice

2018 ◽  
Vol 91 (1) ◽  
pp. 26-36
Author(s):  
Nyúl-Tóth Ádám ◽  
Mészáros Ádám ◽  
Győri Fanni ◽  
Wilhelm Imola ◽  
István A. Krizbai
Keyword(s):  
Endothelial Cells ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
Molecular Level ◽  
Single Gene ◽  
Brain Regions ◽  
Brain Barrier ◽  
Blood Brain ◽  
The Central Nervous System ◽  
Brain And Spinal Cord

Abstract Proper functioning of the nervous system is largely dependent on the precise regulation of the neuronal environment. By shielding the central nervous system (CNS) from potentially harmful substances, the blood-brain barrier (BBB) has an indispensable role in this process. The BBB is a specialized system of endothelial cells lining brain microvessels, which – supported by pericytes and glial cells – form a selective barrier between the blood and the neural tissue. Under abnormal conditions, permeability of the BBB may increase, which may either trigger or aggravate the disease. Since CNS disorders – at least in their initial phase – usually do not involve the whole brain and spinal cord, but are localized to a certain region, our aim was to understand whether the BBB is regionally heterogeneous at the molecular level. By using bioinformatics tools, we analyzed expression levels of genes specific to cerebral endothelial cells, pericytes or astrocytes in different brain territories. Our results revealed regional heterogeneities in the expression of BBB-associated genes in both human and mouse. Expression pattern of efflux transporters – which have a major role in blocking passage of therapeutic agents through the BBB – proved to be diverse both among brain regions and between mouse and human. Our results indicate that: (1) in silico database analyses are suitable for group-based studies on gene functions, overcoming the limitations of single-gene analyses; (2) high-throughput tests should always be validated using other methods; (3) when using animal models, inter-species differences have to be always considered; (4) when comparing different brain regions, the BBB is heterogeneous at the molecular level, and this might have clinical significance.

scholarly journals Cryptococcal Yeast Cells Invade the Central Nervous System via Transcellular Penetration of the Blood-Brain Barrier

2004 ◽  
Vol 72 (9) ◽  
pp. 4985-4995 ◽  
Author(s):  
Yun C. Chang ◽  
Monique F. Stins ◽  
Michael J. McCaffery ◽  
Georgina F. Miller ◽  
Dan R. Pare ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Endothelial Cells ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
Yeast Cells ◽  
Brain Barrier ◽  
Blood Brain ◽  
The Central Nervous System ◽  
The Brain

ABSTRACT Cryptococcal meningoencephalitis develops as a result of hematogenous dissemination of inhaled Cryptococcus neoformans from the lung to the brain. The mechanism(s) by which C. neoformans crosses the blood-brain barrier (BBB) is a key unresolved issue in cryptococcosis. We used both an in vivo mouse model and an in vitro model of the human BBB to investigate the cryptococcal association with and traversal of the BBB. Exposure of human brain microvascular endothelial cells (HBMEC) to C. neoformans triggered the formation of microvillus-like membrane protrusions within 15 to 30 min. Yeast cells of C. neoformans adhered to and were internalized by the HBMEC, and they crossed the HBMEC monolayers via a transcellular pathway without affecting the monolayer integrity. The histopathology of mouse brains obtained after intravenous injection of C. neoformans showed that the yeast cells either were associated with endothelial cells or escaped from the brain capillary vessels into the neuropil by 3 h. C. neoformans was found in the brain parenchyma away from the vessels by 22 h. Association of C. neoformans with the choroid plexus, however, was not detected during up to 10 days of observation. Our findings indicate that C. neoformans cells invade the central nervous system by transcellular crossing of the endothelium of the BBB.

scholarly journals Screening for Interacting Proteins with Peptide Biomarker of Blood–Brain Barrier Alteration under Inflammatory Conditions

2021 ◽  
Vol 22 (9) ◽  
pp. 4725
Author(s):  
Karina Vargas-Sanchez ◽  
Monica Losada-Barragán ◽  
Maria Mogilevskaya ◽  
Susana Novoa-Herrán ◽  
Yehidi Medina ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Neurovascular Unit ◽  
Specific Interaction ◽  
Brain Barrier ◽  
Mass Spectrometry Analysis ◽  
Peptide Ligand ◽  
Inflammatory Conditions ◽  
Blood Brain ◽  
Potential Biomarker

Neurodegenerative diseases are characterized by increased permeability of the blood–brain barrier (BBB) due to alterations in cellular and structural components of the neurovascular unit, particularly in association with neuroinflammation. A previous screening study of peptide ligands to identify molecular alterations of the BBB in neuroinflammation by phage-display, revealed that phage clone 88 presented specific binding affinity to endothelial cells under inflammatory conditions in vivo and in vitro. Here, we aimed to identify the possible target receptor of the peptide ligand 88 expressed under inflammatory conditions. A cross-link test between phage-peptide-88 with IL-1β-stimulated human hCMEC cells, followed by mass spectrometry analysis, was used to identify the target of peptide-88. We modeled the epitope–receptor molecular interaction between peptide-88 and its target by using docking simulations. Three proteins were selected as potential target candidates and tested in enzyme-linked immunosorbent assays with peptide-88: fibronectin, laminin subunit α5 and laminin subunit β-1. Among them, only laminin subunit β-1 presented measurable interaction with peptide-88. Peptide-88 showed specific interaction with laminin subunit β-1, highlighting its importance as a potential biomarker of the laminin changes that may occur at the BBB endothelial cells under pathological inflammation conditions.

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