Endothelial NF-κB Blockade Abrogates ANCA-Induced GN

Abstract

ANCA-associated vasculitis (AAV) is a highly inflammatory condition in which ANCA-activated neutrophils interact with the endothelium, resulting in necrotizing vasculitis. We tested the hypothesis that endothelial NF-B mediates necrotizing crescentic GN (NCGN) and provides a specific treatment target. Reanalysis of kidneys from previously examined murine NCGN disease models revealed NF-B activation in affected kidneys, mostly as a p50/p65 heterodimer, and increased renal expression of NF-B-dependent tumor necrosis factor (TNF-). NF-B activation positively correlated with crescent formation, and nuclear phospho-p65 staining showed NF-B activation within CD31-expressing endothelial cells (ECs) in affected glomeruli. Therefore, we studied the effect of ANCA on NF-B activation in neutrophil/EC cocultures ANCA did not activate NF-B in primed human neutrophils, but ANCA-stimulated primed neutrophils activated NF-B in ECs, at least in part TNF- release. This effect increased endothelial gene transcription and protein production of NF-B-regulated interleukin-8. Moreover, upregulation of endothelial NF-B promoted neutrophil adhesion to EC monolayers, an effect that was inhibited by a specific IKK inhibitor. In a murine NCGN model, prophylactic application of E-selectin-targeted immunoliposomes packed with p65 siRNA to downregulate endothelial NF-B significantly reduced urine abnormalities, renal myeloid cell influx, and NCGN. Increased glomerular endothelial phospho-p65 staining in patients with AAV indicated that NF-B is activated in human NCGN also. We suggest that ANCA-stimulated neutrophils activate endothelial NF-B, which contributes to NCGN and provides a potential therapeutic target in AAV.

Endothelium-targeted delivery of dexamethasone by anti-VCAM-1 SAINT-O-Somes in mouse endotoxemia

“…This data shows that selective delivery of therapeutic molecules to endothelial cells in sepsis can be achieved using Ab VCAM-1 SAINT-O-Somes. Recently we demonstrated that endothelial cell targeted SAINT-O-Somes containing a different drug are actually capable of abrogating the disease process in ANCA-induced glomerulonephritis in mice, confirming effective homing of the SAINT-O-Somes [ 24 ].…”

Animal Models of ANCA Associated Vasculitis

“…Choi et al identified that release of TNF from ANCA-activated neutrophils upregulated NF-κB in endothelial cells, with subsequent IL-8 production. Prophylactic application of immunoliposomes which downregulated endothelial NF-κB was associated with reduced glomerular necrosis (60).…”

Glomerular Endothelial Cells as Instigators of Glomerular Sclerotic Diseases

“…As epigenetic modifications are regulated by epigenetic enzymes, intervening in the expression of epigenetic enzymes can influence the amount of epigenetic modifications. Endothelial cell-specific delivery of siRNA is feasible and this strategy has previously been used to successfully deliver siRNA to inflamed endothelial cells, including specifically GEnCs, and to decrease the expression of the target gene of interest ( Kowalski et al., 2014 ; Choi et al., 2017 ).…”