Intracellular p16^INK4aprofile as targeted protein in human endothelial progenitor cells after chronic asymmetric dimethylarginine exposure

Downregulation of circulating EPCs survival affects the ability to maintain and repair the endothelium as a key feature in vascular homeostasis.The current study intends to describe the intracellular protein profile after chronic asymmetric dimethylarginine (ADMA) exposure using the immunofluorescence technique. Human EPCs as targeted cells were purified from peripheral blood mononuclear cells using Ficoll-based gradient centrifugation, cells were seeded on a culture plate and maintained in an endothelial growth medium (EGM) until 7 days. ADMA exposure was performed on the seventh day and incubate for 24 hours. The intensity of phosphorylated SIRT1 (pSIRT1) and p16INK4a as targeted protein in ADMA treated cells were identified using a confocal laser scanning microscope. After 24 hours of ADMA exposure, intracellular protein expression in human EPCs was changed. Expression of p16INK4a as cells cycle inhibitor protein was significantly higher in ADMA treated cells compared with control cells (p=0.000). Otherwise, the expression of pSIRT1 as a survival cells marker tends to decrease in ADMA treated cells compared with control (p=0.000). Our findings prove that elevated ADMA levels downregulating human EPCs viability.