Visualizing the endothelial glycocalyx in human glioma vasculature

Gliomas are the most common primary brain tumors in adults. However, glioblastoma is especially difficult to treat despite advancements in treatment. Therefore, new and more effective treatments are needed. The endothelial glycocalyx covers the luminal surface of the endothelium and plays an important role in vascular homeostasis. Tumor blood vessels normally have increased permeability, but some of them mimic normal cerebral blood vessels constituting the blood-brain barrier and retain drug-barrier function. Therefore, brain tumor vessels are considered to constitute the blood-tumor barrier. There are few reports on the endothelial glycocalyx in human brain tumor vessels. We aimed to visualize the endothelial glycocalyx in human brain tumor vessels and evaluate its microstructural differences in glioma vessels and normal capillaries. Surgical specimens from patients with glioma who underwent tumor resection at our institution were evaluated. We visualized the microstructures of the brain tumor vessels in human glioma specimens using electron microscopy with lanthanum nitrate. The endothelial glycocalyx was identified in the human glioma vasculature and its microstructure varied between the tumor margin and core. These variations may influence tumor angiogenesis and vascular remodeling, contributing to advancements in targeted therapies and diagnostics for human gliomas.