Induction of Plasmalemmal vesicle-associated protein exacerbates glomerular endothelial injury in thrombotic microangiopathy

Glomerular endothelial cell (GEnC) injury is a common feature across the wide spectrum of glomerular diseases. We recently reported that the endothelial-specific knockout of Krüppel-like factor 4 (Klf4) increases the susceptibility to GEnC injury and subsequent development of subacute thrombotic microangiopathy (TMA). However, the mechanism(s) mediating GEnCs response to injury in TMA are poorly understood. Single nucleus RNA sequencing demonstrated an enrichment in pathways involved in angiogenesis, permeability, focal adhesion, dedifferentiation and cytoskeletal organization in the endothelial cluster in mice with TMA. Plasmalemmal vesicle-associated protein (Plvap), a structural component of fenestral diaphragms, was highly enriched specifically in injured GEnCs. Induction of Plvap in cultured GEnCs increased proliferation, migration and cell permeability with an accompanying loss of mature GEnC markers. Immunostaining for PLVAP in human kidney biopsies confirmed the increase in glomerular PLVAP in TMA, which correlated with a higher grade of glomerular injury. To date, this is the first study to show that the induction of Plvap in GEnCs shifts the cells to an immature state, which might exacerbate glomerular injury in TMA.