Abstract: SA-OR091

Neutrophils Induce Endothelial Cell Injury through the Release of Extracellular Vesicles Containing miRNA in ANCA-Associated Renal Vasculitis

Session Information

Category: Hypertension

  • 1103 Vascular Biology and Dysfunction

Authors

  • Glemain, Alexandre, Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France
  • Néel, Mélanie, Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France
  • Le Bloas, Rozenn, Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France
  • Fakhouri, Fadi, Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France
  • Bruneau, Sarah, Centre de Recherche en Transplantation et Immunologie UMR1064, INSERM, Université de Nantes, Nantes, France
Background

To date, the pathophysiological mechanisms by which neutrophils cause endothelial damage in anti-neutrophil cytoplasm antibodies (ANCA)-associated renal vasculitis (AARV) are not fully elucidated. Some data suggest that neutrophil-derived extracellular vesicles (EV) may contribute to endothelial cell (EC) activation, but the mechanisms by which these EV can induce EC damage in the context of AARV, and the role of miRNA they may contain have not been studied.

Methods

In these studies, we used TaqMan Low Density Arrays to identify miRNA released in EV by ANCA-activated neutrophils that are internalized by microvascular EC in vitro. The consequences of this miRNA transfer were analyzed using an overexpression approach in microvascular EC.

Results

We identified three particular miRNA transferred from ANCA-activated neutrophils to microvascular EC in vitro: miR-223, miR-142-3p and miR-451. The overexpression of miR-142-3p and/or of miR-451 in EC led to profound cell damage, especially in inflammatory conditions (TNFα). This was characterized by the induction of EC apoptosis by miR-142-3p (n=8, P<0.01), the inhibition of EC proliferation by miR-451 (n=8, P<0.05) and as a result, impairment of EC repair and angiogenesis by these two miRNA as observed in wound-healing (n=6, P<0.05) and tube formation (n=7, P<0.05) assays. Using phosphokinase protein arrays, we found that miR-142-3p inhibits the mTORC1, ERK1/2 and eNOS signaling pathways in EC, which may explain its strong effect on EC injury. Moreover, miR-142-3p and miR-451 overexpression in EC resulted in marked activation responses, characterized by induced expression of the leukocyte chemoattractant chemokines CXCL10 (2- to 5-fold), CXCL11 (2- to 3-fold) and IL8 (6-fold), as well as the proinflammatory cytokine IL6 (4-fold), as assessed by mRNA expression arrays. In contrast, miR-223 overexpression had no significant impact on EC responses in our studies.

Conclusion

Collectively, these findings identify miR-142-3p and miR-451 as critical mediators of neutrophil-induced endothelial damage in the course of AARV, and suggest that specific targeting of these miRNA in EC may have implications for the prevention of microvascular injury in AARV patients.

Funding

  • Private Foundation Support