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Abstract: FR-OR39

Extracellular Vesicles and Alport Syndrome: The Role of miR-93 in Modulating Glomerular Cell Biology

Session Information

Category: Glomerular Diseases

  • 1201 Glomerular Diseases: Fibrosis and Extracellular Matrix

Authors

  • Perin, Laura, Children's Hospital of Los Angeles, Los Angeles, California, United States
  • Dedhia, Charmi, Children's Hospital of Los Angeles, Los Angeles, California, United States
  • Aguiari, Paola, Children's Hospital of Los Angeles, Los Angeles, California, United States
  • Petrosyan, Astgik, Children's Hospital of Los Angeles, Los Angeles, California, United States
  • De Filippo, Roger E., Children's Hospital of Los Angeles, Los Angeles, California, United States
  • Sedrakyan, Sargis, Children's Hospital of Los Angeles, Los Angeles, California, United States
Background

miRNAs play important roles in the pathogenesis of various renal diseases miR-93 is a potent regulator of pathways responsible for glomerular damage like VEGF, TGFb, and Msk2. We have evidence that miR-93 is altered in the glomeruli of mice with Alport syndrome (AS, Col4a5-/-), and in glomeruli of AS patients. Here, we investigated the role of miR-93 in mesangial cells, podocytes, and glomerular endothelial cells (GEC) of mouse and human origin. We also used extracellular vesicles (EVs) derived from human amniotic fluid stem cells to assess their disease-modifying activity in vitro and in vivo by regulation of miR-93.

Methods

miR-93 expression was evaluated by qRT-PCR in mesangial cells, podocytes and GEC sorted from glomeruli of male and female WT and homozygous and heterozygous AS mice at different stages of disease (2m, 3.5m, and 5.5m) and in biopsies of AS patients. The role of miR-93-EVs was evaluated in vitro in human glomerular cells using EVmiR93-/-. The therapeutic effect of EVs was tested in vivo. RNA-seq analysis was performed in isolated glomeruli of EV-injected mice vs. controls.

Results


miR-93 expression differs between male and female mice along disease progression. In AS males, miR-93 level was significantly lower in GEC, but not in podocytes or mesangial cells vs. WT cells. miR-93 expression was downregulated in glomeruli and urine of AS patients. Expression of WT1 in PAN damaged human podocytes, of fibronectin and VEGF in damaged human GEC, and expression of PDGFRb in TGFb damaged mesangial cells were restored by miR-93 EV cargo transfer, unlike EVmiR93-/-. EVs showed amelioration of proteinuria and increased lifespan of treated mice. Transcriptomic analysis showed that WT male and female present differences in respiratory and metabolic pathways, extracellular matrix, and cell adhesion molecules. AS males injected with EVs showed improved gene modulations in metabolic function, extracellular matrix interaction, angiogenesis and fibrosis, important miR-93 targeted pathways.

Conclusion

Gender-specific variation in miR-93 expression in glomerular cells might indicate important differences in response to injury in progressive disease. EVs demonstrate great potential to restore lost miR-93 expression and its targets, thus presenting a targeted approach for the treatment of CKD.

Funding

  • NIDDK Support