PRESENCE OF EXOSOMES CONTAINING THE AUTOPHAGY-RELATED PROTEIN VMP1 IN HUMAN SERUM

MARIA NOE GARCIA; PAULA SEPÚLVEDA ACUÑA; FELIPE RENNA; TAMARA ORQUERA; LISANDRO ALLE; SANDRA MUZIETTI; BEATRIZ CARACCIOLO; MARÍA INÉS VACCARO

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Investigación Clínica

PRESENCE OF EXOSOMES CONTAINING THE AUTOPHAGY-RELATED PROTEIN VMP1 IN HUMAN SERUMAbstractVMP1 is a transmembrane protein that participates of the autophagic process. Overexpression of VMP1 induces autophagy even in full nutrient medium. VMP1 is induced in pancreas diseases such as pancreatitis and pancreas ductal adenocarcinoma (PDAC). In both diseases there are an increased need to find early biochemical markers. Autophagy has been implicated in the endosome/exosome secretory pathway. Exosomes are small vesicles (40-120 nm) which are excreted by cells and mediate long distance cell communication. The objective of this work was to evaluate the presence of VMP1 in human serum in response to a pancreatic diseases. By western blot, and using three differents antibodies, we were able to detect VMP1 in human serum from donors (N=20). Since VMP1 possess 6 transmembrane domains and is not a soluble protein, we hypothesize that its presence in serum is as a part of exosomes vesicles. Setting up two exosomes purification protocols, by ultracentrifugation and by magnetic beads, we determined the presence of VMP1 in supernatant of PDAC cell lines. Moreover, this presence was confirmed in the exosomal fraction, even under optimum nutrient conditions. Next, we purified exosomes from human serum and evidenced the presence of VMP1. Finally, in serum samples from patients with confirmed acute pancreatitis diagnosis (N=13) we observe a tendency of increased VMP1 in these subject compared to donors (p