Hyaluronidase-1 impairs endothelial barrier in a subtype of age-related macular degeneration

Polypoidal choroidal vasculopathy (PCV) is characterized by polyp-like dilatation of blood vessels and turbulent blood flow in the choroid of the eye. Here, we cultivated blood outgrowth endothelial cells (BOECs) from PCV patients and normal controls. When BOECs were exposed to heterogeneous flow, single-cell analysis revealed that PCV BOECs preferentially adopted migratory-angiogenic cell state, while normal BOECs undertook proinflammatory cell state. PCV BOECs also had a repressed protective response to flow stress by demonstrating lower mitochondrial functions. We uncovered that elevated hyaluronidase-1 in PCV BOECs led to increased degradation of hyaluronan, a major component of endothelial glycocalyx. Hyaluronidase-1 was correspondingly detected in PCV patient vitreous humor and plasma samples. Notably, knockdown of hyaluronidase-1 in PCV BOECs modulated their abnormal cell migration and barrier permeability due to glycocalyx impairment. Therefore, hyaluronidase-1 inhibition could be a potential therapeutic modality in preserving glycocalyx integrity and endothelial stability in ocular diseases with vascular origin. Overall design: scRNA-seq of patient/donor-derived BOECs subjected to orbital flow