Hydrogen Repairs LPS-Induced Endothelial Progenitor Cells Injury via PI3K/AKT/eNOS Pathway

Abstract

Endotoxins and other harmful substances may cause an increase in permeability in endothelial cells (ECs) monolayers, as well as ECs shrinkage and death to induce lung damage. Lipopolysaccharide (LPS) can impair endothelial progenitor cells (EPCs) functions, including proliferation, migration, and tube formation. EPCs can migrate to the damaged area, differentiate into ECs, and participate in vascular repair, which improves pulmonary capillary endothelial dysfunction and maintains the integrity of the endothelial barrier. Hydrogen (H2) contributes to the repairment of lung injury and the damage of ECs. We therefore speculate that H2 protects the EPCs against LPS-induced damage, and it’s mechanism will be explored. The bone marrow-derived EPCs from ICR Mice were treated with LPS to establish a damaged model. Then EPCs were incubated with H2, and treated with PI3K inhibitor LY294002 and endothelial nitric oxide synthase (eNOS) inhibitor L-NAME. MTT assay, transwell assay and tube formation assay were used to detect the proliferation, migration and angiogenesis of EPCs. The expression levels of target proteins were detected by Western blot. Results found that H2 repaired EPCs proliferation, migration and tube formation functions damaged by LPS. LY294002 and L-NAME significantly inhibited the repaired effect of H2 on LPS-induced dysfunctions of EPCs. H2 also restored levels of phosphor-AKT (p-AKT), eNOS and phosphor-eNOS (p-eNOS) suppressed by LPS. LY294002 significantly inhibited the increase of p-AKT and eNOS and p-eNOS expression exposed by H2. L-NAME significantly inhibited the increase of eNOS and p-eNOS expression induced by H2. H2 repairs the dysfunctions of EPCs induced by LPS, which is mediated by PI3K/AKT/eNOS signaling pathway.

Fucoidan promotes angiogenesis and accelerates wound healing through AKT/Nrf2/HIF‐1α signalling pathway

“…57,58 The incorporation of LY294002 results in AKT phosphorylation inhibition and subsequent suppression of both HIF-1α and Nrf2 expressions. 59,60 Furthermore, the expressions of eNOS and VEGF were significantly inhibited. 61,62 Consistent with the previous reports, we also observed a significant reduction in the expression levels of p-AKT, Nrf2, HIF-1α, eNOS, and VEGF upon LY294002 addition in vitro.…”

“…As a PI3K inhibitor, LY294002 markedly suppresses the downstream phosphorylation of AKT and hence is commonly employed as an AKT inhibitor 57,58 . The incorporation of LY294002 results in AKT phosphorylation inhibition and subsequent suppression of both HIF‐1α and Nrf2 expressions 59,60 . Furthermore, the expressions of eNOS and VEGF were significantly inhibited 61,62 .…”

Hydrogen therapy: recent advances and emerging materials

“…44,45 Additionally, hydrogen can modulate various inflammation-associated signaling pathways, such as inhibiting NF-κB activation to suppress the release of pro-inflammatory cytokines like TNF-α, IL-1β, and IL-6; 46 furthermore, inhibition of the MAPK pathway reduces pro-inflammatory cytokine release while regulating cell survival; 47,48 and inhibition of the PI3K/Akt pathway suppresses downstream inflammatory mediators and apoptotic proteins, potentially repairing the functionality of lung endothelial progenitor cells. 49 Moreover, by potentiating the Nrf2/ HO-1 pathway, hydrogen induces antioxidant and cytoprotective genes, suppresses pro-inflammatory cytokine production, and mitigates oxidative stress. 50,51 Due to the natural characteristics and ease of administration of hydrogen gas, respiratory diseases characterized by inflammatory processes have also undergone thorough investigation in clinical contexts.…”

Potent anti-inflammatory responses: Role of hydrogen in IL-1α dominated early phase systemic inflammation

“…Hydrogen is a colorless, odorless, tasteless gas that has been proven to have obvious anti-inflammatory effects in animal experiments (Li et al, 2019;Li et al, 2021;Mu et al, 2022;Yin et al, 2022) and clinical practice (Guan et al, 2020;Wang et al, 2020;Yang et al, 2020;Singh et al, 2021;Botek et al, 2022;Luo et al, 2022). However, the early dynamic process of the inflammatory response caused by lipopolysaccharide (LPS) and the anti-inflammatory effect of hydrogen has not been definitively reported.…”