To study the genomic changes in senescent porcine coronary arterial endothelial cells by multiple passaging in vitro

Nitric oxide helps to prevent endothelial dysfunction and senescence. This study aimed to define genomic and proteomic changes in cultured porcine senescent endothelial cells and their resemblance with those observed in regenerated endothelial cells. Senescent endothelial cells were produced by passaging primary porcine coronary arterial endothelial cells until passage four. The protein presence of endothelial nitric oxide synthase, cyclic GMP levels [basal and during stimulation (bradykinin and A23187)], were reduced. The mRNA expression level was measured by microarray assays. Genes related to oxidative stress [superoxide dismutase (MnSOD), glutathione peroxidase 3, glutathione S-transferase M1] were downregulated, extracellular matrix components (type III collagen, thrombospondin 1 and 3, transforming growth factor beta) upregulated and nuclear factor kappa B (NFKB)-signaling pathway [IkappaB, TNF receptor-associated factor 1 and 5 (TRAF1 and 5)] activated in senescent cells. The differential gene expression of MnSOD and TRAF5 was confirmed at the protein level by Western blotting and biochemical assay (MnSOD). The basal and stimulated (by tumor necrosis factor-alpha) levels of NFKB were augmented as demonstrated by electrophoretic mobility shift assay. In summary, cultured senescent endothelial cells exhibit reduced nitric oxide production, and decreased antioxidative, proliferative capacities, augmented expression of extracellular matrix components and activation of NFKB. These molecular changes do not exactly mimick those occurring during endothelial regeneration in vivo.

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