Proteomic Analysis of Urinary Extracellular Vesicles

ABSTRACT: Novel therapies in autosomal dominant polycystic kidney disease (ADPKD) signal the need for markers of disease progression or response to therapy. This study aimed to identify disease-associated proteins in urinary extracellular vesicles (uEVs), which include exosomes, in patients with ADPKD. We performed quantitative proteomics on uEVs using a labeled approach (healthy vs. ADPKD) and then using a label-free approach in different subjects (healthy vs. ADPKD vs. non-ADPKD chronic kidney disease [CKD]). In both experiments, thirty proteins were consistently more abundant (≥ 2-fold) in ADPKD-uEVs compared with healthy and CKD uEVs. Of these proteins, periplakin, envoplakin, villin-1, complement C3 and C9 were selected for confirmation, because (1) they were also significantly overrepresented in pathway analysis, and (2) they have been previously implicated in the pathogenesis of ADPKD. Immunoblotting was used to validate the proteomics results, confirming higher abundances of the selected proteins in ADPKD-uEVs in three independent groups of ADPKD-patients. While villin-1, periplakin and envoplakin were more abundant in advanced stages of the disease, complement was already higher in uEVs of young ADPKD patients with preserved renal function. Furthermore, all five proteins correlated positively with height adjusted total kidney volume. The proteins of interest were also analyzed in kidney tissues from kidney-specific-tamoxifen-inducible Pkd1-deletion mice, demonstrating higher expression in more severe stages of the disease. In summary, proteomic analysis of uEVs identified plakins and complement as disease-associated proteins in ADPKD. These proteins are new candidates for evaluation as biomarkers or targets for therapy in ADPKD.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Urine

DISEASE(S): Polycystic Kidney

SUBMITTER: Jeroen Demmers  

LAB HEAD: Jeroen Demmers

PROVIDER: PXD003298 | Pride | 2016-03-15

REPOSITORIES: Pride