Human Brain Microvascular Endothelial Cells and Umbilical Vein Endothelial Cells Differentially Facilitate Leukocyte Recruitment and Utilize Chemokines for T Cell Migration

Endothelial cells that functionally express blood brain barrier (BBB) properties are useful surrogates for studying leukocyte-endothelial cell interactions at the BBB. In this study, we compared two different endothelial cellular models: transfected human brain microvascular endothelial cells (THBMECs) and human umbilical vein endothelial cells (HUVECs). With each grow under optimal conditions, confluent THBMEC cultures showed continuous occludin and ZO-1 immunoreactivity, while HUVEC cultures exhibited punctate ZO-1 expression at sites of cell-cell contact only. Confluent THBMEC cultures on 24-well collagen-coated transwell inserts had significantly higher transendothelial electrical resistance (TEER) and lower solute permeability than HUVECs. Confluent THBMECs were more restrictive for mononuclear cell migration than HUVECs. Only THBMECs utilized abluminal CCL5 to facilitate T-lymphocyte migration in vitro although both THBMECs and HUVECs employed CCL3 to facilitate T cell migration. These data establish baseline conditions for using THBMECs to develop in vitro BBB models for studying leukocyte-endothelial interactions during neuroinflammation

Cervicomedullary junction compression caused by vertebral artery dolichoectasia and requiring surgical treatment. Case report

A case of progressive brainstem syndrome secondary to vertebral artery (VA) dolichoectasia is reported. The patient presented with partial bilateral abduction paralysis, which progressed to quadriparesis, ataxia, and areflexia. The initial diagnosis was stroke, but because of the patient\u27s deterioration, a diagnosis of Miller-Fisher syndrome was made. Neuroimages obtained at that time revealed an ectatic left VA with minimal cervicomedullary compression. The patient continued to deteriorate despite medical management. Follow-up imaging demonstrated worsened cervicomedullary compression. An emergency posterior fossa neurovascular decompression was performed using a Gore-Tex sling and resulted in mild neurological improvement. This case emphasizes that early recognition and surgical intervention to prevent progressive neurological sequelae are crucial in symptomatic VA dolichoectasia

Glial-derived neurotrophic factor is essential for blood-nerve barrier functional recovery in an experimental murine model of traumatic peripheral neuropathy.

There is emerging evidence that glial-derived neurotrophic factor (GDNF) is a potent inducer of restrictive barrier function in tight junction-forming microvascular endothelium and epithelium, including the human blood-nerve barrier (BNB) in vitro. We sought to determine the role of GDNF in restoring BNB function in vivo by evaluating sciatic nerve horseradish peroxidase (HRP) permeability in tamoxifen-inducible GDNF conditional knockout (CKO) adult mice following non-transecting crush injury via electron microscopy, with appropriate wildtype (WT) and heterozygous (HET) littermate controls. A total of 24 age-, genotype- and sex-matched mice >12 weeks of age were injected with 30 mg/kg HRP via tail vein injection 7 or 14 days following unilateral sciatic nerve crush, and both sciatic nerves were harvested 30 minutes later for morphometric assessment by light and electron microscopy. The number and percentage of HRP-permeable endoneurial microvessels were ascertained to determine the effect of GDNF in restoring barrier function in vivo. Following sciatic nerve crush, there was significant upregulation in GDNF protein expression in WT and HET mice that was abrogated in CKO mice. GDNF significantly restored sciatic nerve BNB HRP impermeability to near normal levels by day 7, with complete restoration seen by day 14 in WT and HET mice. A significant recovery lag was observed in CKO mice. This effect was independent on VE-Cadherin or claudin-5 expression on endoneurial microvessels. These results imply an important role of GDNF in restoring restrictive BNB function in vivo, suggesting a potential strategy to re-establish the restrictive endoneurial microenvironment following traumatic peripheral neuropathies

Antibodies used for immunohistochemistry and western blot.

<p>Abbreviations: FITC: fluorescein, H+L: heavy and light chain, HRP: horseradish peroxidase, N/A: not applicable, TXRD: Texas Red.</p

Effect of CCR2 drug inhibition on sm-EAN-associated inflammatory demyelination.

<p>Representative digital photomicrographs of toluidine-blue stained, 1 μm semi-thin plastic embedded axial sections of mouse sciatic nerves show multiple foci of demyelinated axons associated with infiltrated mononuclear cells (double white asterisk) in vehicle controls (A), compared to the preserved myelin architecture and lack of inflammation seen in CCR2INB treated mice (B). Clusters of thinly myelinated axons (double black asterisk) surrounded by large myelinated axons, suggestive of recent multifocal axonal injury and repair are commonly seen in human IVIg-treated mice, associated with scattered foci of mononuclear cells (black arrows; C). Higher magnification digital photomicrographs further demonstrate the mononuclear cell-mediated demyelination in Vehicle-treated controls as expected in untreated sm-EAN (white arrows). Active leukocyte extravasation at an endoneurial microvessel (EMV) is also seen (D). Foci of mononuclear cells (white arrow) are rarely seen in CCR2INB treated (white arrow; E); these are more common in human IVIg treated mice (black arrows; F). Scale bar  =  100 μm (A–C), 50 μm (D–F).</p