Angiogenesis, the process of forming new blood vessels, is an important process in both cardiovascular health and disease. A recent student has identified a novel role for plasma membrane calcium ATPase (PMCA) 4 in angiogenesis through mediating endothelial cell migration and tubule formation. However, the role of PMCA1 has yet to be investigated. Here, we aim to establish the role of PMCA1 in angiogenesis and endothelial cell behaviours. We hypothesise that PMCA1 modulates key endothelial cell processes which are associated with the development of new blood vessels.
Knockdown of PMCA1 was achieved in human umbilical vein endothelial cells (HUVECs) using siRNA (si-PMCA1) and confirmed with qPCR. Following PMCA1 knockdown, HUVEC viability and migration was assessed using the MTT assay and wound healing assay respectively. Additionally, the rate of HUVEC proliferation was evaluated by Ki-67 immunofluorescence staining. Finally, apoptosis of HUVECs was investigated using a caspase-Glo3/7 assay.
Transient knockdown of PMCA1 in HUVECs resulted in an 85% reduction in PMCA1 gene expression. Phenotypically, si-PMCA1 HUVECs display decreased HUVEC cell viability but also reduced apoptosis. Staining for Ki-67 revealed that si-PMCA1 HUVECs had a larger percentage of cells active in the cell cycle. Furthermore, loss of PMCA1 impairs migration of HUVECs into the ‘wound’, 24 hours after the scratch assay was performed.
Overall it appears loss of PMCA1 is detrimental for HUVEC viability and migration which may result in a reduction in angiogenesis, although further work is required to establish the pumps direct role in vessel formation.