Abstract P3166: Circulating Extracellular Vesicles In Human Cardiorenal Syndrome Promote Renal Injury In Kidney On A Chip System

Abstract

Objective: Cardiorenal syndrome (CRS)—renal injury during heart failure (HF)—is linked to higher morbidity. Whether circulating extracellular vesicles (EVs) and their RNA cargo directly impact its pathogenesis remains unclear. Methods: We investigated the transcriptional effects of circulating EVs from patients with CRS on renal epithelial/endothelial cells, using a microfluidic kidney chip model (KC). We performed small RNA-seq and regression against serum creatinine to prioritize subsets of EV miRNAs associated with renal function. Long RNA-seq was performed on the same EVs to identify the source organs via deconvolution analysis. In silico pathway analysis, human genetics, and interrogation of expression of miRNA target genes in the KC model and in a separate cohort of individuals post-renal transplant with microarray-based gene expression were performed for validation. To enhance the rigor of our observation, kidney epithelial cells were treated with corresponding anti-miRs and ago-miRs under various experimental conditions. Results: Renal epithelial and endothelial cells in the KC model exhibited uptake of EVs. EVs from patients with CRS led to higher expression of renal injury markers ( IL18 , NGAL , KIM-1 ), a greater cystatin C secretion relative to non-CRS EVs. Small RNA-seq and regression identified 15 miRNAs related to creatinine, targeting 1143 gene targets specifying pathways relevant to renal injury, including TGF-b and AMPK signaling. Deconvolution analysis identified 6 major organs as the main source of the EVs. Finally, we observed directionally consistent changes in expression of TGF-b pathway members (BMP6, FST, TIMP3) in KC model exposed to CRS EVs, as well as in the cells treated with corresponding inhibitors and mimics of miRNAs. Similar trend was observed in renal tissue after transplant rejection. Mendelian randomization suggested a role for FST in renal function. Conclusion: EVs from patients with CRS directly elicit adverse transcriptional and phenotypic responses in a KC model by regulating biologically relevant pathways, suggesting a novel role for EVs in CRS.