Session Time: 2:30pm-4:00pm
Presentation Time: 2:42pm-2:54pm
Location: Room 313
*Purpose: Recent data suggest a strong correlation between kidney injury and the occurrence of accelerated senescence process, known as “Inflammaging”. However, the role of TEC senescence and its mediators in the transplant kidney remains incompletely understood. Extracellulr vesicles (EVs) have pivotal role in cellular communication and might induce pathogenic processes.
*Methods: Renal biopsies of 10 transplanted patients with Acute and Chronic Antibody-Mediated Rejection (AMR) were collected with serum samples to isolate extracellular vesicles (EVs, 5E+4EVs/cells target for 24h); primary culture of Renal Proximal Tubular Cells (TEC) were incubated with EVs, then p21 and p53 gene levels were measured by qPCR and Senescence-associated β-galactosidase (SA-β-gal) staining was performed to assess cellular senescence. IHC staining for markers of Inflammaging (p16INK4a and Klotho) were performed on paraffin tissues.
*Results: Compared with control biopsies, both Acute and Chronic AMR presented significant tubular senescence as indicated by p16INK4a expression; interestingly, p16INK4a was significantly expressed in chronic compared with acute AMR patients (p<0.05). In vitro, the exposure of TEC to serum of AMR patients induced senescence by up-regulating p21 and p53 gene levels, compared to basal condition (p<0.05). We then activated TEC with serum derived-EVs; interestingly, we found that EVs from AMR patients induced tubular senescence by promoting a significant increase in p21, p53 and Cyp1b1 expression and down-regulation of Klotho in TEC (p<0.05). Finally, AMR derived-EVs induced a higher number of SA-β-gal+ TEC compared with control serum from stable transplant patients (p<0.05). In vitro, TEC under EVs activation appeared larger and polynucleotide indicating the appearance of a senescence phenotype.
*Conclusions: Our data first demonstrated that patients with AMR present circulating serum EVs with strong capacity to induce accelerated aging in TEC. Considering the occurrence of TEC senescence both in vitro and in vivo, this new pathogenic process may be suitable for specific therapeutic intervention.
To cite this abstract in AMA style:Divella C, Stasi A, Franzin R, Sallustio F, Curci C, Merlotti G, Quaglia M, Gesualdo L, Cantaluppi V, Castellano G. Extracellular Vesicles (EV) Mediate Antibody-Independent Tubular Senescence via Cyclin-Dependent Kinase Inhibitors p21/p16 in Antibody-Mediated Rejection (AMR) [abstract]. Am J Transplant. 2019; 19 (suppl 3). https://atcmeetingabstracts.com/abstract/extracellular-vesicles-ev-mediate-antibody-independent-tubular-senescence-via-cyclin-dependent-kinase-inhibitors-p21-p16-in-antibody-mediated-rejection-amr/. Accessed February 16, 2020.
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