A human model of Membranous Nephropathy on-a-chip
Astgik Petrosyan, PhD, Paolo Cravedi, MD, Valentina Villani, PhD, Roger De Filippo, MD, Laura Perin, PhD, Stefano Da Sacco, PhD.
Children's Hospital Los Angeles, Los Angeles, CA, USA.
BACKGROUND: Primary membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults worldwide. MN involves the deposition of auto-antibodies against podocyte-expressed antigens in the glomerular subepithelial space, causing podocyte injury and initiating renal damage leading to kidney failure in one third of patients. The study of mechanisms responsible for MN pathogenesis is challenged by the lack of in vitro systems that recapitulate human disease. We have developed a novel glomerulus-on-a-chip system (GOAC) using human primary podocytes human glomerular endothelial cells (GEC) in combination with OrganoPlates and assessed the functional response to human MN serum.
METHODS: Human podocytes were seeded on microfluidic chips with hGEC. Immunofluorescence and WB were performed for podocyte, endothelial and GBM markers. Barrier selective-permeability was investigated. Chips were cultured with serum from MN patients or healthy individuals. Functional response was assessed by albumin permeability assay. IgG/IgG4 deposition was assessed by immunofluorescence while mechanisms of action were explored by Western Blotting and immunostaining.
RESULTS: This system recapitulates salient characteristics and functions of the in vivo glomerular filtration barrier (GFB). The GOAC is permeable to inulin and impermeable to albumin. When exposed to the serum of subjects with MN, the chip displayed IgG and complement C3 deposition on the podocytes and loss of permselectivity to albumin to an extent comparable to urinary protein loss in respective patients. Moreover, we have found evidence suggesting that changes in the ILK/MAPK/SNAIL signaling pathway might contribute to podocyte damage during MN pathogenesis.
CONCLUSIONS: We have successfully developed a glomerulus-on-a-chip system that closely mimics the GFB structure and provides a powerful tool for studying renal regenerative and disease mechanisms in proteinuric diseases, toxicity effects and could inform the discovery of new drugs. This system will increase our ability to individualize treatments, thus ultimately benefiting patients affected by renal failure.
Back to 2019 Abstracts
