Hydrogen‑rich medium alleviates high glucose‑induced oxidative stress and parthanatos in rat Schwann cells in�vitro

Abstract

Diabetic peripheral neuropathy (DPN) is considered to be the most common cause of microvascular diabetic complications, for which no effective therapies currently exist. Previous studies have identified that oxidative stress is the common pathway in all possible hypotheses for the induction of DPN, and poly(ADP-ribose) (PAR) polymerase-1 (PARP-1)-dependent cell death (parthanatos) is key in the pathogenic mechanisms of neurodegenerative disease. The aim of the present study was to investigate the protective effects and corresponding mechanisms of hydrogen-rich medium (HM) on high glucose (HG)-induced oxidative stress and parthanatos in primary rat Schwann cells (RSCs) in vitro. The RSCs were divided into groups and treated for 48 h. Cell counting kit-8 and lactate dehydrogenase assays were used to detect cell viability and cytotoxicity, respectively; intracellular OH− levels were measured using a DCFH-DA assay; concentrations of peroxynitrite (ONOO−) and 8-hydroxy deoxyguanosine (8-OHdG) were evaluated with an enzyme-linked immunosorbent assay; relative expression levels of parthanatos-related proteins [PAR, nucleus apoptosis-inducing factor (AIF) and total AIF] were analyzed using western blot analysis, and immunofluorescence was used to determine the nuclear translocation of AIF. After 48 h, HG was shown to induce severe oxidative stress and promote marked levels of parthanatos in the RSCs. Treatment with HM inhibited HG-induced oxidative stress by reducing the production of OH− and ONOO− and suppressed parthanatos by downregulating the levels of 8-OHdG, the expression of PAR and the nuclear translocation of AIF. HM improved cell viability and inhibited cytotoxicity under the HG condition. These results indicate that HM effectively reduces HG-induced oxidative stress in RSCs and protects them against parthanatos. Therefore, HM may be a novel treatment for DPN.

Protective effects of hydrogen‑rich saline against experimental diabetic peripheral neuropathy via activation of the mitochondrial ATP‑sensitive potassium channel channels in rats

“…In the present study, HS treatment resulted in a reversal of the lower paw withdrawal threshold and a reduction of MNCV deficiency in diabetic rats. Oxidative stress is one of the main causes of the complex pathophysiology of DPN (1,7). Previous studies have indicated that hyperglycemia increases the production of free radicals by increasing intracellular glucose oxidation, which subsequently results in neurotoxicity (7).…”

“…Previous studies have indicated the details of HS preparation (7,18). At 0.4 MPa, H2 was dissolved in normal saline for 6 h, until it reached supersaturation.…”

“…The saturated HS was sterilized using γ rays and preserved in an aluminum bag at an atmospheric pressure of 4, as described by Ohsawa et al (19). The concentration of hydrogen gas at different time points were detected by a special microelectrode as described in the authors' previous article (7). The HS was replaced weekly to ensure that the hydrogen concentration was maintained at >0.6 mmol/l, which is the 3/4 of the saturation concentration (0.8 mmol/l) of hydrogen and is enough to produce biological effects (10,20).…”

“…Due to the complex pathogenicity of DPN, investigations into novel injury mechanism interventions for its treatment are urgently required (5). Some studies have suggested that long-term hyperglycemia can cause energy metabolism disorders and vascular imbalance (6,7). Additionally, mitochondrial ATP-sensitive potassium (Mito-K-ATP) channels function as the high-fidelity metabolic sensors, which couple the intracellular metabolic state to membrane excitability and play a homeostatic role in blood glucose regulation in organisms (8).…”

“…In addition, reactive oxygen species (ROS) and inflammatory cytokines also serve different roles at a variety of stages, including in the early and late stages of DPN (7). This is consistent with previous studies that have demonstrated that the inhibition of ROS and inflammation may restore energy metabolism, vascular balance, and improve or reverse neuropathy (7,10).…”