Abstract
Consumption of different PUFAs (polyunsaturated fatty acids) can induce functional changes in blood vessels via endothelial cells, which interact with dietary factors in the circulation. The basement membrane that separates the endothelium from the smooth muscle cells of the medial layer can also influence the functional state of endothelial cells. However, the effect of basement membrane on the endothelial response to dietary PUFAs in relation to growth state (e.g. proliferation versus quiescence) has never been investigated. We therefore compared the viability (CCK kit) and proliferation (bromodeoxyuridine incorporation) of EA.hy926 endothelial cells grown on Matrigel or collagen versus non-coated plates. EA.hy926 viability and proliferation were also assessed after treatment with 0–150 μM of PUFAs [linoleic acid (LA), arachidonic acid (AA), α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)]. Our study showed that only cells grown on Matrigel-coated plates reached quiescence after becoming confluent with a decreased level of MCM2 and p-cyclin D1 (T286), increased levels of p27kip1 and a low level of apoptosis and senescence. AA, EPA and DHA decreased the viability and proliferation of subconfluent cells grown on plastic dishes in a dose-dependent manner, while the presence of Matrigel made the cells resistant to these adverse effects. Confluent cell viability was less sensitive to higher concentrations of AA, EPA and DHA than subconfluent cells, and a significant increase in caspase-3 cleavage was only observed in confluent cells treated with DHA. Higher concentrations of AA, EPA and DHA suppressed DNA synthesis by both subconfluent and confluent cells, while precursor C18 PUFAs (LA and ALA) had no negative effects on viability and proliferation. Our study is the first to show that extracellular matrix and growth state are important factors in the EA.hy926 cell response to PUFAs, and that the mechanisms by which individual PUFAs operate may be growth state-dependent.
Highlights
The endothelium is formed by a single layer of endothelial cells and lines the luminal surface of all blood vessels
The current study investigated how EA.hy926 endothelial cells, a fusion of human umbilical vein endothelial cells with human carcinoma A549 cells [11], respond to different n-6 [linoleic acid (LA) and arachidonic acid (AA)] and n-3 [α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] polyunsaturated fatty acids (PUFAs) in terms of viability and proliferation when they are grown on different extracellular matrix (ECM) substrates
When EA.hy926 endothelial cells were grown on collagen coated plates, the DNA synthesis rate remained high from day 4 to day 10 (Fig 2C), similar to cells grown without basement membrane
Summary
The endothelium is formed by a single layer of endothelial cells and lines the luminal surface of all blood vessels. Adhesion of endothelial cells to basement membrane proteins through integrins is important for maintaining endothelial cell viability and strongly influences other functions such as proliferation, migration, vessel formation and blood vessel stabilization [2]. Total non-esterified fatty acid (FA) levels can reach 300 μM in healthy individuals and higher in persons with type 2 diabetes [3] At these concentrations, FAs could have a major influence on vascular physiology. The effect of PUFAs on the viability and proliferation of endothelial cells in the context of both ECM substrate and growth state has not been investigated. The response of EA.hy926 endothelial cells to PUFAs in different growth states (i.e., growing and confluent) was considered in relation to proteins involved in cell viability and proliferation as a means of investigating their mechanisms of action
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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
