Abstract
and aims The accumulation of the adipose tissue (AT) in the sup- and subepicardium of the atrial myocardium is associated with a high risk of atrial fibrillation. Here we addressed the question of the cellular origin of atrial AT. Human right atrial specimen obtained during cardiac surgery were used for histological, biochemical studies and to harvest epicardial progenitors. Cells were characterized using flow cytometry, proteomic and genic expression assays and maintained in culture conditions, in some experiments they were co cultured with human atrial myocytes using a Transwell system. In atrial section, epicardial progenitors expressing the pre-adipocyte factor 1 (Pref-1) were detected in the epicardial and sub-epicardial layer which contained a number of progenitor cells referred as epicardic progenitorderived cells (EPDCs). Some EPDCs expressed Pref-1 suggesting that they could engaged in the adipocyte pathways. This was tested in vitro using EPDCs harvested from human right atrial samples (n=20). From 1 st to 5-6 cells passages, EPDCs underwent an epithelial-to-mesenchymal transition (EMT), acquired mesenchymal phenotypes and could differentiate into osteocyte or chondrocyte. When cultured using an adipogenic medium, around 40±6% of EPDCs cells showed lipid droplet colored with oil red and expressed mature adipocyte perilipin marker. Culture medium enriched with the secretome of human atria too induced the differentiation of EPDCs in adipocytes (n=6). A shift from pre- to mature adipocytes was indicated by the detection of Pref-1 at 7 but not 30 days of culture, it was the opposite for perilipin. Human atrial myocyte could be the source of pro-adipogenic factor. In fact, after 7 days in coculture, EPDCs are differentiated into adipocytes (n=6). Human EPDCs from atria can differentiate into adipocyte; factors secreted by atrial myocytes regulate this differentiation process. The author hereby declares no conflict of interest
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call