Ex Vivo Expansion of Human outgrowth Endothelial Cells Leads to IL-8-Mediated Replicative Senescence and Impaired Vasoreparative Function

Abstract

Harnessing outgrowth endothelial cells (OECs) for vasoreparative therapy and tissue engineering requires efficient ex vivo expansion. How such expansion impacts on OEC function is largely unknown. In this study, we show that OECs become permanently cell-cycle arrested after ex vivo expansion, which is associated with enlarged cell size, b-galactosidase activity, DNA damage, tumor suppressor pathway activation, and significant transcriptome changes. These senescence hallmarks were coupled with low telomerase activity and telomere shortening, indicating replicative senescence. OEC senescence limited their regenerative potential by impairing vasoreparative properties in vitro and in vivo. Integrated transcriptomeproteome analysis identified inflammatory signaling pathways as major mechanistic components of the OEC senescence program. In particular, IL8 was an important facilitator of this senescence; depletion of IL8 in OECs significantly extended ex vivo lifespan, delayed replicative senescence, and enhanced function. While the ability to expand OEC numbers prior to autologous or allogeneic therapy remains a useful property, their replicative senescence and associated impairment of vasorepair needs to be considered. This study also suggests that modulation of the senescence-associated secretory phenotype could be used to optimize OEC therapy.

Long-Term Expansion in Platelet Lysate Increases Growth of Peripheral Blood-Derived Endothelial-Colony Forming Cells and Their Growth Factor-Induced Sprouting Capacity

“…growth factors, hypoxia) that are commonly used to study the physiological process such as angiogenic sprouting[34]. Previous comparison of angiogenic ability of ECFCs expanded in medium containing FBS or PL has unraveled that the serum supplement modulates sprouting ability of these cells[35].…”

Purple sweet potato color inhibits endothelial premature senescence by blocking the NLRP3 inflammasome

“…Interestingly, PSPC effectively renewed the endothelial function of D-gal-treated HUVECs by remarkably we determined the release of inflammatory cytokine interleukin 8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) from HUVECs. Several papershave also demonstrated that these pro-inflammatory factors are crucial facilitators of endothelial senescence[11,40]. The results of the ELISA analysis showed that both the concentration of IL-8 and MCP-1 in cells treated with D-gal for 24 and 48 hours were higher than that in the control cells and PSPC markedly prevented the release of these endothelial function markers in D-gal-treated cells (Fig.…”

“…Moreover, the release of IL-8 and MCP-1 can be promoted by IL-1β [67,68]. Papers have demonstrated that senescent endothelial cells displayed increased expression of IL-8 and MCP-1, and these cytokines mediated senescence and impaired endothelial function [40,69]. Thus, the levels of IL-8 and MCP-1 can be used as the markers and the cause of endothelial cell senescence.…”

Epigenetic Changes in Endothelial Progenitors as a Possible Cellular Basis for Glycemic Memory in Diabetic Vascular Complications

“…Nevertheless, when compared to their mature counterparts, progenitor cells, that is, ECFCs/OECs, have been shown to undergo a higher number of population doublings and possess a longer in vitro lifespan [135]. Furthermore, umbilical cord blood-derived ECFCs have an enhanced proliferative potential when compared to those obtained from peripheral blood [109].…”