Grain and Bean Lysates Improve Function of Endothelial Progenitor Cells from Human Peripheral Blood: Involvement of the Endogenous Antioxidant Defenses

Abstract

Increased oxidative stress contributes to the functional impairment of endothelial progenitor cells (EPCs), the pivotal players in the servicing of the endothelial cell lining. Several evidences suggest that decreasing oxidative stress by natural compounds with antioxidant properties may improve EPCs bioactivity. Here, we investigated the effects of Lisosan G (LG), a Triticum Sativum grain powder, and Lady Joy (LJ), a bean lysate, on function of EPCs exposed to oxidative stress. Peripheral blood mononuclear cells were isolated and plated on fibronectin-coated culture dishes; adherent cells, identified as early EPCs, were pre-treated with different concentrations of LG and LJ and incubated with hydrogen peroxide (H2O2). Viability, senescence, adhesion, ROS production and antioxidant enzymes gene expression were evaluated. Lysate-mediated Nrf-2 (nuclear factor (erythroid-derived 2)-like 2)/ARE (antioxidant response element) activation, a modulator of oxidative stress, was assessed by immunocytochemistry. Lady Joy 0.35–0.7 mg/ml increases EPCs viability; pre-treatment with either LG 0.7 mg/ml and LJ 0.35–0.7 mg/ml protect EPCs viability against H2O2-induced injury. LG 0.7 and LJ 0.35–0.7 mg/ml improve EPCs adhesion; pre-treatment with either LG 0.35 and 0.7 mg/ml or LJ 0.35, 0.7 and 1.4 mg/ml preserve adhesiveness of EPCs exposed to H2O2. Senescence is attenuated in EPCs incubated with lysates 0.35 mg/ml. After exposure to H2O2, LG pre-treated cells show a lower senescence than untreated EPCs. Lysates significantly decrease H2O2-induced ROS generation. Both lysates increase glutathione peroxidase-1 and superoxide dismutase-2 (SOD-2) expression; upon H2O2 exposure, pre-treatment with LJ allows higher SOD-2 expression. Heme oxigenase-1 increases in EPCs pre-treated with LG even upon H2O2 exposure. Finally, incubation with LG 0.7 mg/ml results in Nrf-2 translocation into the nucleus both at baseline and after the oxidative challenge. Our data suggest a protective effect of lysates on EPCs exposed to oxidative stress through the involvement of antioxidant systems. Lisosan G seems to activate the Nrf-2/ARE pathways.

A Fermented Whole Grain Prevents Lipopolysaccharides‐Induced Dysfunction in Human Endothelial Progenitor Cells

“…The highest concentration showing no effect on cells viability (10  μ g/mL) was used in all subsequent experiments (cell viability, as determined by AB reagent, was >95%). Conversely, the dose of LG (0.7 mg/mL) was selected based on a previous study [17]. EPCs were treated with 0.7 mg/mL LG and/or 10  μ g/mL LPS as previously described in Study Protocol.…”

“…On the other hand, treatment of EPCs with the prebiotic Lisosan G, a fermented powder from organic whole wheat grains [13, 16, 17] (LG and 1 h LG experimental conditions), reduces intracellular ROS, without affecting expression of both proinflammatory and proapoptotic factors; expression of antioxidant enzymes was also significantly increased. Interestingly, we have observed that ROS levels were reduced to the same extent in EPCs continuously exposed to LG (LG) and in EPCs pretreated with LG (1 h LG) and that those changes were consistent when EPCs were examined at 5-hour and 24-hour exposures (Figures 4(a) and 4(b)).…”

“…The resulting lysate was extracted with distilled water and sonicated (three cycles: 10 s on/10 s off). Then, the extract was centrifuged for 10 minutes at 2300 ×g at 4°C (Jouan CR3i centrifuge, Newport Pagnell, UK), and the supernatant was collected, filtered (0.2  μ m VWR International PBI, Milan, Italy), and kept at 4°C in the dark until use [17]. …”

“…More recently, protective effects of LG on cell functional properties have been described in human endothelial progenitor cells (EPCs) exposed to oxidative stress. LG enhances EPCs viability and adhesiveness, while reducing their senescence, probably via augmentation of antioxidant defense systems and activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway [17]. …”

Nutraceuticals and cardiovascular risk: potential role of EPCs modulation

“…In an our study EPCs treatment with a fermented grain, Lisosan G, increased not only viability but also cell function through the enhancement of antioxidative defenses, involving Nrf-2 pathway [79] . Whole grain cereals contain a lot of nutrients and bioactive substances that have health-promoting effects and epidemiological studies extensively demonstrated that whole grains consumption correlates with a reduced risk of type 2 diabetes and cardiovascular diseases [80] .…”