Cytoprotective effect of dieckol on human endothelial progenitor cells (hEPCs) from oxidative stress-induced apoptosis

Abstract

Although endothelial progenitor cells (EPCs) have been used to promote revascularization after peripheral or myocardial ischemia, excess amounts of reactive oxygen species (ROS) are often involved in senescence and apoptosis of EPCs, thereby causing defective neovascularization and reduced or failed recovery. Here, we examined the cytoprotective effect of Ecklonia cava-derived antioxidant dieckol (DK) on oxidative stress-induced apoptosis in EPCs to improve EPC bioactivity for vessel repair. Although H2O2 (10 (- 3) M) increased the intracellular ROS level in EPCs, DK (10ug/ml) pretreatment suppressed the H2O2-induced ROS increase and drastically reduced the ratios of apoptotic cells. H2O2-induced ROS increased the phosphorylation of p38 MAPK and JNK; this was inhibited by DK pretreatment. H2O2 treatment increased the phosphorylation of NF-κB, which was blocked by pretreatment with SB 203580, a p38 MAPK inhibitor, or SP 600125, a JNK inhibitor. H2O2 decreased the cellular levels of Bcl-2 and c-IAPs, cellular inhibitors of apoptosis proteins, but increased caspase-3 activation. However, all these effects were inhibited by pretreatment with DK. Injection of DK-mixed EPCs (DK + EPCs) into myocardial ischemic sites in vivo induced cellular proliferation and survival of cells at the ischemic sites and, thereby, enhanced the secretion of angiogenic cytokines at the ischemic sites. These results show that DK + EPC exhibit markedly enhanced anti-apoptotic and antioxidative capabilities, unlike that shown by EPCs alone; thus, they contribute to improved repair of ischemic myocardial injury through cell survival and angiogenic cytokine production.

Diazoxide preconditioning of endothelial progenitor cells improves their ability to repair the infarcted myocardium

“…EPCs impart ischemic tissue repair by promotion of cell proliferation and angiogenesis (Lee et al, 2013;Sun et al, 2014). The expression of Ki67 (associated with cell proliferation), a-SMA and vWF (an indicator of blood vessels) was observed to be significantly greater in DZ EPCs transplanted group (Figure 7).…”

“…It induces cell damage by propagation of inflammation, apoptosis and cell death. H 2 O 2 has been commonly used to induce in vitro oxidative stress for mimicking the ischemic tissue environment (Pfister et al, 2013;Lee et al, 2013). Therefore H 2 O 2 was used to induce oxidative stress in EPCs in vitro in this study.…”

“…Most of the transplanted cells die in the adverse conditions in infarcted myocardium because of ischemia, inflammation, and apoptosis (Higuchi et al, 2009;Zhu et al, 2014). EPCs survival is also compromised under oxidative stress conditions (Lee et al, 2013). In this regard, various preconditioning strategies are being currently explored to improve the survival of stem and progenitor cells to be used for transplantation in injured tissues.…”

Brown algae phlorotannins enhance the tumoricidal effect of cisplatin and ameliorate cisplatin nephrotoxicity

“…ROS formation can activate the Akt pathway, which is upstream of the NFκB pathway, and can therefore induce activation of NFκB [34]. Notably, many sea and terrestrial polyphenols are generally recognized as antioxidants and show cytoprotective effects in some cells by reducing ROS levels [20,[35][36][37]. These observations suggest that polyphenols can act as a double-edged sword, both as an antioxidant and a prooxidant.…”

From alga to omega; have we reached peak (fish) oil?

“…67 They also display anti-allergy, anti-coagulative, anti-hypertensive, anti-diabetic, immuno-modulatory, antimutagenic, anti-tumour and anti-cancer activity and can reasonably be categorised as gerosuppressants. [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69] In light of the above, it seems probable that many and perhaps all the health benefits associated with the tradition Inuit diet, and which were attributed to the o3 highly unsaturated fatty acids they consumed, were at least partly due to their co-ingestion of phlorotannins.…”