Telomerase- and angiogenesis-related gene responses to irradiation in human umbilical vein endothelial cells

Abstract

In this study, we investigated the effects of ionizing radiation (IR) on human umbilical vein endothelial cells (HUVECs) in the context of senescence. HUVECs at passage number (PN)1, PN2 and PN3 were exposed to irradiation (2 Gy). The growth rate of the HUVECS was measured by proliferation assay and senescence-associated β-galactosidase assay was used to measure the number of senescent cells. Telomerase activity and the expression of telomerase- and angiogenesis-related genes were measured by telomerase assay and real-time PCR, respectively. The number of senescent cells was significantly increased in the irradiated HUVECs at all PNs. Compared to the controls, telomerase activity, the expression of human telomerase reverse transcriptase (hTERT) and c-Myc in the irradiated HUVECs were downregulated during serial passage. The downregulation of vascular endothelial growth factor (VEGF) was observed in the irradiated HUVECs as the PN increased. The data presented in this study may aid in the understanding of the mechanisms behind IR‑induced EC senescence and telomerase- and angiogenesis‑related gene response.

Senescent Cells: A Therapeutic Target in Cardiovascular Diseases

“…EC senescence seems to drive dysfunctional phenotypes through upregulation of several canonical SASP factors, such as IL-6, TNF-α, and PAI-1, leading to dysfunction in other vascular cells [108,109]. Angiogenesis is another aspect of endothelial function, protecting tissues against ischemia in ischemic heart disease and peripheral arterial diseases, primarily through vascular endothelial growth factor (VEGF) [110], fibroblast growth factor (FGF) [111], and hypoxia-inducible factor (HIF) 1α [112]. Senescent ECs decrease expression of these factors in vessels due to signaling through the p53-p21 senescence pathways, as evidenced by increased angiogenesis after this pathway is inhibited [96].…”

Human telomerase reverse transcriptase regulates vascular endothelial growth factor expression via human papillomavirus oncogene E7 in HPV-18-positive cervical cancer cells

“…Increasing evidence has shown that telomerase expressions are associated with VEGF expressions in both normal and cancer cells [28,[32][33][34][35]. For instance, telomerase activities, as well as hTERT and VEGF expressions, were down-regulated during serial passage in irradiated human umbilical vein endothelial cells [38]. Expressions of hTERT were significantly associated with VEGF expressions in prostate, gastric [37], and breast cancers [39].…”

Evaluation of Energy Balance on Human Telomerase Reverse Transcriptase (hTERT) Alternative Splicing by Semi-quantitative RT-PCR in Human Umbilical Vein Endothelial Cells

“…Quantitative real time RT-PCR, PCR-based TRAP analysis, linear range of TRAP assay are most often used methods. [2627282930] Some investigators have also used RT-PCR for assessment of telomerase gene expression in HUVECs in instances like assessment of telomerase activity by RT-PCR after induction of TERT over-expression. [3132] Indeed, RT-PCR was used to assess telomerase gene expression in HUVECs after administration of agents, which increase telomerase gene expression as 17beta-estradiol.…”