Lyso-globotriaosylsphingosine induces endothelial dysfunction via autophagy-dependent regulation of necroptosis

Fabry disease is a lysosomal storage disorder characterized by the lysosomal accumulations of glycosphingolipids in a variety of cytotypes, which include endothelial cells. The disease is inherited and originates from an error in glycosphingolipid catabolism caused by insufficient α-galactosidase A activity, which causes uncontrolled progressive storage of intracellular globotriaosylceramide (Gb3) in the vasculature and extracellular accumulation of lyso-Gb3 (a deacetylated soluble form of Gb3). Necrosis can lead to inflammation, which exacerbates necrosis and creates a positive feedback loop that triggers necroinflammation. However, the role played by Necroptosis, a form of programmed necrotic cell death, in the cell-to-cell inflammatory reaction between epithelial and endothelial cells is unclear. Thus, the present study was undertaken to determine whether lyso-Gb3 induces Necroptosis and whether Necroptosis inhibition protects endothelial dysfunction against lyso-Gb3 inflamed retinal pigment epithelial cells. We found lyso-Gb3 induced Necroptosis of a retinal pigment epithelial cell line (ARPE-19) in an autophagy-dependent manner and that conditioned media (CM) from ARPE-19 cells treated with lyso-Gb3 induced the Necroptosis, inflammation, and senescence of human umbilical vein endothelial cells. In addition, a pharmacological study showed CM from lyso-Gb3 treated ARPE-19 cells induced endothelial Necroptosis, inflammation, and senescence were significantly inhibited by an Autophagy Inhibitor (3-MA) and by two Necroptosis inhibitors (necrostatin and GSK-872), respectively. These results demonstrate lyso-Gb3 induces Necroptosis via Autophagy and suggest that lyso-Gb3 inflamed retinal pigment epithelial cells trigger endothelial dysfunction via the autophagy-dependent Necroptosis pathway. This study suggests the involvement of a novel autophagy-dependent Necroptosis pathway in the regulation of endothelial dysfunction in Fabry disease.

Autophagy; Cellular senescence; Glycosphingolipids; Inflammation; Necroptosis.