Use of cultured cerebral capillary endothelial cells in modeling the central nervous system availability of 2′,3′-dideoxyinosine

Author(s):  
Mark D. Johnson ◽  
Bradley D. Anderson
2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yinan Zhao ◽  
Yanguo Xin ◽  
Zhiyi He ◽  
Wenyu Hu

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.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 492
Author(s):  
Charlotte A. René ◽  
Robin J. Parks

The central nervous system (CNS) is surrounded by the blood–brain barrier (BBB), a semipermeable border of endothelial cells that prevents pathogens, solutes and most molecules from non-selectively crossing into the CNS. Thus, the BBB acts to protect the CNS from potentially deleterious insults. Unfortunately, the BBB also frequently presents a significant barrier to therapies, impeding passage of drugs and biologicals to target cells within the CNS. This review provides an overview of different approaches to deliver therapeutics across the BBB, with an emphasis in extracellular vesicles as delivery vehicles to the CNS.


2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Christoph Konradt ◽  
Norikiyo Ueno ◽  
David A. Christian ◽  
Jonathan H. Delong ◽  
Gretchen Harms Pritchard ◽  
...  

1984 ◽  
Vol 118 (4) ◽  
pp. 243-248 ◽  
Author(s):  
Kenichirou Inomata ◽  
Takafumi Yoshioka ◽  
Fumio Nasu ◽  
Hiroshi Mayahara

2013 ◽  
Vol 59 (1) ◽  
pp. 180-189 ◽  
Author(s):  
Robert R Langley ◽  
Isaiah J Fidler

BACKGROUND It is estimated that at least 200 000 cases of brain metastases occur each year in the US, which is 10 times the number of patients diagnosed with primary brain tumors. Brain metastasis is associated with poor prognosis, neurological deterioration, diminished quality of life, and extremely short survival. Favorable interactions between tumor cells and cerebral microvascular endothelial cells encourage tumor growth in the central nervous system, while tumor cell interactions with astrocytes protect brain metastases from the cytotoxic effects of chemotherapy. CONTENT We review the pathogenesis of brain metastasis and emphasize the contributions of microvascular endothelial cells and astrocytes to disease progression and therapeutic resistance. Animal models used to study brain metastasis are also discussed. SUMMARY Brain metastasis has many unmet clinical needs. There are few clinically relevant tumor models and no targeted therapies specific for brain metastases, and the mean survival for untreated patients is 5 weeks. Improved clinical outcomes are dependent on an enhanced understanding of the metastasis-initiating population of cells and the identification of microenvironmental factors that encourage disease progression in the central nervous system.


2015 ◽  
Vol 21 (13) ◽  
pp. 1644-1654 ◽  
Author(s):  
Samira Saadoun ◽  
Marios C Papadopoulos

Background: It is unclear why AQP4-IgG primarily causes central nervous system lesions by activating complement, but generally spares peripheral AQP4-expressing organs. Objectives: To determine whether peripheral AQP4-expressing cells are protected from complement-mediated damage by expressing complement regulators. Methods: Human tissue and cultured human cells were immunostained for aquaporin-4 (AQP4), CD46, CD55 and CD59. We also determined the vulnerability to AQP4-IgG and complement-mediated damage of astrocytes cultured alone or co-cultured with endothelial cells. Results: In normal brain, astrocyte end-feet express AQP4, but are devoid of CD46, CD55 and CD59. Immunoreactivity for CD46, CD55 and CD59 is not increased in or around neuromyelitis optica lesions. In kidney AQP4 is co-expressed with CD46 and CD55, in stomach AQP4 is co-expressed with CD46 and in skeletal muscle AQP4 is co-expressed with CD46. Astrocytes cultured alone co-express AQP4 and CD59 but, in astrocyte-endothelial co-cultures, AQP4 is found in cell processes devoid of CD59. Astrocytes co-cultured with endothelial cells are more vulnerable to AQP4-IgG and complement-mediated lysis than astrocytes cultured alone. Conclusions: Complement regulators protect peripheral organs, but not the central nervous system, from AQP4-IgG and complement-mediated damage. Our findings may explain why neuromyelitis optica primarily damages the central nervous system, but spares peripheral organs.


2021 ◽  
Vol 22 (15) ◽  
pp. 8248
Author(s):  
Ximena Vásquez ◽  
Pilar Sánchez-Gómez ◽  
Verónica Palma

Glioblastoma (GBM) is the most aggressive and common primary tumor of the central nervous system. It is characterized by having an infiltrating growth and by the presence of an excessive and aberrant vasculature. Some of the mechanisms that promote this neovascularization are angiogenesis and the transdifferentiation of tumor cells into endothelial cells or pericytes. In all these processes, the release of extracellular microvesicles by tumor cells plays an important role. Tumor cell-derived extracellular microvesicles contain pro-angiogenic molecules such as VEGF, which promote the formation of blood vessels and the recruitment of pericytes that reinforce these structures. The present study summarizes and discusses recent data from different investigations suggesting that Netrin-1, a highly versatile protein recently postulated as a non-canonical angiogenic ligand, could participate in the promotion of neovascularization processes in GBM. The relevance of determining the angiogenic signaling pathways associated with the interaction of Netrin-1 with its receptors is posed. Furthermore, we speculate that this molecule could form part of the microvesicles that favor abnormal tumor vasculature. Based on the studies presented, this review proposes Netrin-1 as a novel biomarker for GBM progression and vascularization.


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