Endothelial surface translocation of mitochondrial PDCE2 involves the non-canonical secretory autophagy pathway: putative molecular target for radiation-guided drug delivery

In this study we examined the mechanism of PDCE2 trafficking in human endothelial cells to better understand its suitability as a vascular target. Ionizing radiation induced PDCE2 surface localization in association with accumulation of autophagosome markers (L3CB and p62) indicative of late-stage inhibition of autophagic flux. This effect was abolished in the presence of Rapamycin, an autophagy-inducer, but replicated in the presence of Bafilomycin A, an autophagy blocker. PDCE2 co-localized with lysosomal markers of the canonical degradative autophagy pathway in response to radiation but also with recycling endosomes and SNARE proteins responsible for autophagosome-plasma membrane fusion. These findings demonstrate that radiation-induced blockade of autophagic flux stimulates redirection of intracellular molecules such as PDCE2 to the cell surface via a non-canonical secretory autophagy pathway. Intracellular membrane proteins trafficked in this way could provide a unique pool of radiation biomarkers for therapeutic drug delivery.PMID:34097858 | DOI:10.1016/j.yexcr.2021.112688

Source: Experimental Cell Research - June 7, 2021 Category: Cytology Authors: F Faqihi M A Stoodley L S McRobb Source Type: research