Physiological electrical fields (EFs) can direct some important angiogenic responses of endothelial cells such as directional migration, orientation and proliferation. It has been reported that human umbilical vein endothelial cells (HUVEC) and human microvasculature endothelial cells (HMEC) migrate in opposite directions; to anode and cathode, respectively. Although, in the present study both cell types migrated toward the cathode, HUVEC directedness started at 50mV/mm while HMEC directedness started at 100mV/mm. These results suggest that EFs can promote wound healing by directing endothelial cells to the wound site since EFs of 40 to 100 mV/mm are present in normal healing wounds. EFs also increased cell proliferation and orientated the cleavage plane of dividing cells perpendicular to the EF vector in both endothelial cell lines. The present study showed for the first the time that EFs upregulated the expression of the chemokine receptors CXCR4 and CXCR2 as well as upregulating the levels of phosphorylation of both chemokines in HUVEC and HMEC. It also showed differences of chemokine receptors used by HUVEC and HMEC cells in the early stages of electrotaxis. Ionizing radiation has been shown to directly phosphorylate VEGF receptors in the absence of its ligand VEGF. A question was raised: in the absence of the ligands are EFs able to directly phosphorylate the chemokine receptors? Results showed that in starved HUVEC cells EFs had no effect on the phosphorylation levels of CXCR4 and CXCR2 however in starved HMEC cells an EF may have a direct effect on the phosphorylation levels of CXCR4 and CXCR2. Therefore, EFs represent a physical stimulus that could directly phosphorylate proteins in the absence of its ligand. This work substantiate the importance of endogenous EFs in directing endothelial cells and suggests that EFs might be developed as a component in the clinic to control angiogenesis.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:720585 |
| Date | January 2016 |
| Creators | Cunha, Filipa |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=232613 |
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