Metabolic Syndrome Blunts the Capacity of Mesenchymal Stem Cell‐Derived Extracellular Vesicles to Preserve the Post‐Stenotic Kidney in Swine Renal Artery Stenosis

Background Mesenchymal stem/stromal cells (MSCs) release extracellular vesicles (EVs), which shuttle proteins to recipient cells, promoting cellular repair. We hypothesized that cardiovascular risk factors may alter the pattern of proteins packed within MSC‐derived EVs, blunting their capacity to preserve the post‐stenotic kidney in pigs with metabolic syndrome (MetS) and renal artery stenosis (RAS). Methods We compared the protein cargo of EVs to their parent MSCs obtained from pigs with MetS and Lean controls. Porcine MSCs were harvested from abdominal fat after 16 weeks of Lean‐ or MetS‐diet (n=5 each), and their EVs isolated. Following LC‐MS/MS proteomics, clustering analysis was performed to identify primary functional categories of proteins enriched in Lean‐ and MetS‐EVs. In addition, MetS pigs were studied after 16 weeks of RAS untreated or treated 4 weeks earlier with a single intrarenal delivery of allogeneic labeled Lean‐ or MetS‐EVs (2.5x10^5/Kg). Lean and MetS Sham served as controls (n=6 each). Single‐kidney volume, renal blood flow (RBF), and glomerular filtration rate (GFR) were studied in‐vivo (multi‐detector CT), and tubular injury (Periodic Acid Schiff) and fibrosis (Trichrome) ex‐vivo. Results Proteomics analysis identified 6,690 and 6,790 distinct proteins in Lean‐ and MetS‐EVs, respectively. Differential expression analysis revealed that 91 proteins were upregulated in Lean‐EVs and 130 proteins in MetS‐EVs compared to their parent MSCs (FDR<0.05 and log2 fold‐change EVs/MSCs>2). Proteins enriched exclusively in Lean‐EVs modulate pathways related to the MSC reparative capacity, including cell proliferation, differentiation, and activation, as well as transforming growth factor‐β signaling (Figure 1A). Contrarily, proteins enriched only in MetS‐EVs are linked to pro‐inflammatory pathways, including acute inflammatory response, leukocyte transendothelial migration, and cytokine production (Figure 1B). Blood pressure was elevated in all MetS groups and all RAS groups develop moderate, but significant stenosis of a similar degree (Table). EVs were detected in the stenotic‐kidney 4 weeks after injection (Figure 2A). Renal volume, RBF, and GFR, which increased in MetS compared to Lean (consistent with hyperfiltration), fell in MetS+RAS, but restored in pigs treated with Lean‐EVs. Lean‐EVs also attenuated tubular injury and renal fibrosis (Figure 2B). Yet, these renoprotective effects were blunted in pigs treated with MetS‐EVs. Conclusion MetS alters the protein cargo of porcine MSC‐derived EVs, selectively packaging specific pro‐inflammatory signatures. Intrarenal delivery of Lean‐EVs attenuated renal injury and fibrosis and improved function in pigs with MetS+RAS, whereas these beneficial effects were blunted in pigs treated with MetS‐EVs. Therefore, our observations suggest that approaches to improve the therapeutic efficacy of autologous MSC‐derived EVs might be useful for patients with MetS+RAS. Support or Funding Information This study was partly supported by the National Institutes of Health grant numbers: DK104273, HL123160, DK102325, and DK106427. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .