Objective To study the changes of receptor activator of nuclear factor-κB ligand (RANKL, an osteoclastogenesis-promoting factor) and osteoprotegerin (OPG, the decoy receptor for RANKL), oxidative stress and bone turnover markers in obstructive sleep apnea-hypopnea syndrome (OSAHS), in order to understand the potential mechanisms underlying bone loss in OSAHS patients. Methods Ninety-eight male patients with OSAHS, confirmed by polysomnography (PSG) study, were enrolled. The patients were divided into mild-moderate groups and severe groups. Forty-two male subjects who were confirmed as not having OSAHS served as the controls. The subjects’ bone mineral density (BMD) and T-score were assessed in lumbar spine and femoral neck using dual-energy X-ray absorptiometry. Blood samples were collected from all subjects for measurement of RANKL, OPG, the bone formation marker bone-specific alkaline phosphatase (BAP), the bone resorption marker tartrate-resistant acid phosphatase-5b (TRAP-5b), total antioxidant capacity (TAOC). Twenty-eight severe OSAHS patients accepted continuous positive airway pressure (CPAP) treatment voluntarily. After 6 months, PSG was conducted, and serum RANKL, OPG, TAOC, TRAP-5b, BAP was measured after six months treatment. Results The BMD, T-score of the femoral neck and the lumbar spine were significantly lower in OSAHS patients as compared to the control group. The level of BAP was significantly decreased in the OSAHS group as compared to the control group, and there was no significant difference in TRAP-5b level between two groups. As compared with the control group, levels of OPG, TAOC and the OPG/RANKL ratio decreased significantly. None of these parameters (BMD, T-score, RANKL, OPG, TRAP-5b, BAP) showed significant difference between patients with mild-moderate and severe OSAHS group. Correlation analysis showed that the apnea hypopnea index and oxygen desaturation index were correlated with TAOC. BAP level was positively correlated with TAOC and lowest pulse oxygen saturation. The serum level of TAOC was lower in the OSAHS group after CPAP therapy, but the levels of RANKL, OPG, TRAP-5b, BAP were not different. As compared with the OSAHS group before CPAP therapy, the BMD of the femoral neck and the lumbar spine were not significant difference. Conclusions In patients with OSAHS, the oxidative stress response is enhanced, and imbalance of OPG/RANKL is shifted, which participates in the occurrence of osteoporosis. The oxidative stress injury of severe OSAHS patients was relieved after non-invasive ventilation treatment, but the effect of oxidative stress response on bone metabolism still needs further evaluation.
Reactive oxygen species (ROS) play an important role in the pathogenesis of various cardiovascular diseases, by leading to cell apoptosis and thus causing organic injuries. Anti-ROS therapy is highly anticipated, but currently, there is still no appropriate prevention method. Studies have shown that thioredoxin (Trx), being a kind of significant endogenous antioxidant system, has excellent antioxidant capacity. Promotion of Trx can reduce key biomolecules to eliminate ROS or regulate many signaling pathways, thus resisting ROS injuries, which may be a new anti-ROS strategy. Therefore, we reviewed the research progress of Trx in cardiac antioxidant therapy to discuss its potential and possibility to be a target for prevention of heart-related ROS injury.
Acute lung injury (ALI), in which various factors inside and outside the lung lead to hypoxemic respiratory insufficiency and even the development of acute respiratory distress syndrome, has a high morbidity and mortality rate, and its pathogenesis is characterized by complex signaling pathways and limited therapeutic options. A large number of studies have reported that nuclear factor kappa B (NF-κB), phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase (MAPK), AMP-activated protein kinase (AMPK), vascular endothelial growth factors (VEGF) and JAK/signal transducer and activator of transcription (STAT) signaling pathways are all related to the inflammatory response of ALI, and they are involved in regulating the inflammatory response process of ALI individually or cooperatively. Therefore, this article reviews the research progress on the pathogenesis-related signaling pathways and the drug interventions, aiming to provide a reference for early intervention in lung injury, optimizing the donor pool to increase the proportion of donation after cardiac death and providing quality donor protection conditions.
ObjectiveTo investigate the effect of ozone on oxidative stress and energy metabolism change of blood from aortic dissection (AD) patients for providing preliminary evidence of application of ozonated autohemotherapy (ozone-AHT) in AD patients. MethodsTwenty AD patients (16 males and 4 females with a mean age of 48.51±10.21 years) were consecutively included in the First Affiliated Hospital of Harbin Medical University from March 2016 to August 2016, and blood samples were collected from all participants and ozonized in vitro at different ozone concentrations (0 μg/ml, 40 μg/ml, 60 μg/ml, 80 μg/ml, 160 μg/ml). Malondialdehyde (MDA), red blood cells (RBCs) superoxide dismutase (SOD), Na+-K+-ATP, 2,3-bisphosphoglyceric acid (2,3-DPG) at different ozone concentrations were evaluated by enzyme-linked immunosorbent assay (ELISA). ResultsIn the control group (0 μg/ml), the content of postoperative MDA was significantly higher than that of preoperation (P<0.05). The contents of postoperative SOD, Na+-K+-ATP and 2,3-DPG were significantly lower than that of preoperation (P<0.05). The content of MDA at the concentrations of 40 μg/ml, 60 μg/ml, 80 μg/ml group increased after the operation (P>0.05), and the SOD, Na+-K+-ATP, 2,3-DPG decreased compared with the preoperation (P>0.05). But all the values were not statistically significant at the concentrations of 40 μg/ml, 80 μg/ml and 160 μg/ml respectively between preoperation and postoperation (P>0.05). Compared with other concentration groups, the content of preoperative and postoperative MDA increased in the ozone group (160 μg/ml), and oppositely, the contents ofpreoperative and postoperative SOD, Na+-K+- ATP and 2,3-DPG decreased (P<0.05). Conclusion The concentrations of 40 to 80 μg/ml of ozone can improve the antioxidant capacity of erythrocyte membrane, reduce oxidative stress in blood samples of AD patients and improve the energy metabolism of erythrocyte membranes, so the concentration range of ozone is safe and feasible for the ozone-AHT of perioperative AD.
The aim of this research is to investigate the influence of microencapsulation on the expression of the oxidative stress genes and exogenous regulation of HepG2 cells. We compared the expression of hemeoxygenase-1 (HO-1) and glutathione S-transferases-A1 (GST-A1) in HepG2 cells under different culture conditions through real-time PCR. The effects of exogenous antioxidants on cell viability and albumin levels were also evaluated through MTT assay and ELISA assay. The results showed that after culturing for 6 and 16 days, the expression levels of HO-1 in encapsulated cells were approximately 4.9 and 3.1 times higher than that of monolayer cells at the same culture period; As for the expression levels of GST-A1, they were elevated to 11.2 and 33 times of monolayer cells (P<0.05). Accordingly, we found that NAC at 5-10 mmol/L significantly increased the viability by 40%-70% and the biosynthetic function by 20%-30% in microencapsulated HepG2 cells (P<0.05). GSH increased the viability of the encapsulated cells by 20%-55% and the biosynthetic function by 15% (P<0.05). In conclusion, oxidative stress exists in the microcapsules and affects genes expression. Exogenous antioxidants can prevent the inhibition effects of oxidative stress on cellular growth.
ObjectiveTo investigate the effect of nicotinamide mononucleotide adenosyl transferase 3 (NMNAT3) on the mitochondrial function and anti-oxidative stress of rabbit bone marrow mesenchymal stem cells (BMSCs) under oxidative stress in vitro by regulating nicotinamide adenine dinucleotide (NAD+) levels.MethodsThe bone marrow of femur and tibia of New Zealand white rabbits were extracted. BMSCs were isolated and cultured in vitro by density gradient centrifugation combined with adherent culture. The third generation cells were identified by flow cytometry and multi-directional induction. Overexpression of NMNAT3 gene was transfected into rabbit BMSCs by enhanced green fluorescent protein (EGFP) labeled lentivirus (BMSCs/Lv-NMNAT3-EGFP), and then the expression of NMNAT3 was detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot and cell proliferation by cell counting kit 8 (CCK-8) method. BMSCs transfected with negative lentivirus (BMSCs/Lv-EGFP) and untransfected BMSCs were used as controls. The oxidative stress injury cell model was established by using H2O2 to treat rabbit BMSCs. According to the experimental treatment conditions, they were divided into 4 groups: Group A was normal BMSCs without H2O2 treatment; untransfected BMSCs, BMSCs/Lv-EGFP, and BMSCs/Lv-NMNAT3-EGFP in groups B, C, and D were treated with H2O2 simulated oxidative stress, respectively. The effects of NMNAT3 on the mitochondrial function of BMSCs under oxidative stress [changes of mitochondrial membrane potential, NAD+ and adenosine triphosphate (ATP) levels], the changes of anti-oxidative stress ability of BMSCs [reactive oxygen species (ROS) and malondialdehyde (MDA) levels, manganese superoxide dismutase (Mn-SOD) and catalase (CAT) activities], and the effects of BMSCs on senescence and apoptosis [senescence associated-β-galactosidase (SA-β-gal) staining and TUNEL staining] were detected after 24 hours of treatment.ResultsThe rabbit BMSCs were successfully isolated and cultured in vitro. The stable strain of rabbit BMSCs with high expression of NMNAT3 gene was successfully obtained by lentiviral transfection, and the expressions of NMNAT3 gene and protein significantly increased (P<0.05). There was no significant difference in the trend of cell proliferation compared with normal BMSCs. After treatment with H2O2, the function of mitochondria was damaged and apoptosis increased in all groups. However, compared with groups B and C, the group D showed that the mitochondrial function of BMSCs improved, the membrane potential increased, the level of NAD+ and ATP synthesis of mitochondria increased; the anti-oxidative stress ability of BMSCs enhanced, the levels of ROS and MDA decreased, and the activities of antioxidant enzymes (Mn-SOD, CAT) increased; and the proportion of SA-β-gal positive cells and the rate of apoptosis decreased. The differences in all indicators between group D and groups B and C were significant (P<0.05).ConclusionNMNAT3 can effectively improve the mitochondrial function of rabbit BMSCs via increasing the NAD+ levels, and enhance its anti-oxidative stress and improve the survival of BMSCs under oxidative stress conditions.
Objective To investigate the feasibility of selenium-methylselenocysteine (SMC) to promote peripheral nerve regeneration and its mechanism of action. Methods Rat Schwann cells RSC96 cells were randomly divided into 5 groups, which were group A (without any treatment, control group), group B (adding 100 μmol/L H2O2), group C (adding 100 μmol/L H2O2+100 μmol/L SMC), group D (adding 100 μmol/L H2O2+200 μmol/L SMC), group E (adding 100 μmol/L H2O2+400 μmol/L SMC); the effect of SMC on cell proliferation was detected by MTT method, and the level of oxidative stress was detected by immunofluorescence for free radicals [reactive oxygen species (ROS)] after determining the appropriate dose group. Thirty-six 4-week-old male Sprague Dawley rats were randomly divided into 3 groups, namely, the sham operation group (Sham group), the sciatic nerve injury group (PNI group), and the SMC treatment group (SMC group), with 12 rats in each group; the rats in the PNI group were fed with food and water normally after modelling operation, and the rats in the SMC group were added 0.75 mg/kg SMC to the drinking water every day. At 4 weeks after operation, the sciatic nerves of rats in each group were sampled for neuroelectrophysiological detection of highest potential of compound muscle action potential (CMAP). The levels of inflammatory factors [interleukin 17 (IL-17), IL-6, IL-10 and oxidative stress factors catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA)] were detected by ELISA assay. The luxol fast blue (LFB) staining was used to observe the myelin density, fluorescence intensity of glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) was observed by immunofluorescence staining, and myelin morphology was observed by transmission electron microscopy with measurement of axon diameter. Western blot was used to detect the protein expressions of p38 mitogen-activated protein kinases (p38MAPK), phosphorylated p38MAPK (p-p38MAPK), heme oxygenase 1 (HO-1), and nuclear factor erythroid 2-related factor 2 (Nrf2). ResultsMTT assay showed that the addition of SMC significantly promoted the proliferation of RSC96 cells, and the low concentration could achieve an effective effect, so the treatment method of group C was selected for the subsequent experiments; ROS immunofluorescence test showed that group B showed a significant increase in the intensity of ROS fluorescence compared with that of group A, and group C showed a significant decrease in the intensity of ROS fluorescence compared with that of group B (P<0.05). Neuroelectrophysiological tests showed that the highest potential of CMAP in SMC group was significantly higher than that in PNI and Sham groups (P<0.05). ELISA assay showed that the levels of IL-6, IL-17, and MDA in PNI group were significantly higher than those in Sham group, and the levels of IL-10, SOD, and CAT were significantly lower; the levels of IL-6, IL-17, and MDA in SMC group were significantly lower than those in PNI group, and the levels of IL-10, SOD, and CAT were significantly higher (P<0.05). LFB staining and transmission electron microscopy showed that the myelin density and the diameter of axons in the SMC group were significantly higher than those of the PNI group and the Sham group (P<0.05). Immunofluorescence staining showed that the fluorescence intensity of GFAP and MBP in the SMC group were significantly stronger than those in the PNI group and Sham group (P<0.05). Western blot showed that the relative expressions of Nrf2 and HO-1 proteins in the SMC group were significantly higher than those in the PNI group and Sham group, and the ratio of p-p38MAPK/p38MAPK proteins was significantly higher in the PNI group than that in the SMC group and Sham group (P<0.05). Conclusion SMC may inhibit oxidative stress and inflammation after nerve injury by up-regulating the Nrf2/HO-1 pathway, and then inhibit the phosphorylation of p38MAPK pathway to promote the proliferation of Schwann cells, which ultimately promotes the formation of myelin sheaths and accelerates the regeneration of peripheral nerves.
ObjectiveTo identify causal effects and potential mechanisms of oxidative stress (OS)-related genes in lung cancer. MethodsOS-related genes were extracted from the GeneCards database. Integration analysis of genome-wide association study (GWAS) data for lung cancer with gene expression and DNA methylation quantitative trait locus (QTL), including eQTL and mQTL in blood was performed using the summary data-based Mendelian randomization (SMR) approach to determine the causal relationship between OS-related genes and lung cancer risk. Colocalization analysis of OS-related gene QTL and lung cancer risk locus was performed to gain insight into the potential regulatory mechanisms of lung cancer risk. ResultsA total of 1 188 OS-related genes were obtained from the GeneCards database. A potential causal relationship between OS-related genes and lung cancer was identified by SMR analysis. AGER expression level [OR=1.944, 95%CI (1.431, 2.640), P<0.001], and ATF6B expression level [OR=1.508, 95%CI (1.287, 1.767), P<0.001] were associated with lung cancer risk. Meanwhile, ATF6B methylation level was also associated with lung cancer risk. ConclusionOS-related genes are associated with lung cancer, which may be a potential target of anti-cancer drugs.
ObjectiveTo explore the protective effects of sodium valproic acid (VPA) on oxidative stress injury of osteoblasts induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and its mechanism. Methods Osteoblasts were isolated from the skulls of 10 newborn Sprague Dawley rats and cultured by tissue block method, and the 1st generation cells were identified by alkaline phosphatase (ALP) and alizarin red staining. The 3rd generation osteoblasts were cultured with 2-18 μmol/L CCCP for 2-18 minutes, and cell counting kit 8 (CCK-8) was used to detect the cell survival rate. An appropriate inhibitory concentration and culture time were selected for the preparation of osteoblasts oxidative stress injury model based on half maximal concentration principle. The cells were cultured with 0.2- 2.0 mmol/mL VPA for 12-72 hours, and CCK-8 was used to detect cell activity, and appropriate concentration was selected for further treatment. The 3rd generation cells were randomly divided into 4 groups, including blank control group (normal cultured cells), CCCP group (the cells were cultured according to the selected appropriate CCCP concentration and culture time), VPA+CCCP group (the cells were pretreated according to the appropriate VAP concentration and culture time, and then cultured with CCCP), VPA+CCCP+ML385 group (the cells were pretreated with 10 μmol/L Nrf inhibitor ML385 for 2 hours before VPA treatment, and other treatments were the same as VPA+CCCP group). After the above treatment was complete, the cells of 4 groups were taken to detect oxidative stress indicators [reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA)], cell apoptosis rate, ALP/alizarin red staining, and the relative expressions of osteogenic related proteins [bone morphogenetic protein 2 (BMP-2), RUNX2], anti-apoptotic family protein (Bcl2), apoptotic core protein (Cleaved-Caspase-3, Bax), channel protein (Nrf2) by Western blot. Results The osteoblasts were successfully extracted. According to the results of CCK-8 assay, the oxidative stress injury model was established by 10 μmol/L CCCP cultured for 10 minutes and 0.8 mmol/mL VPA cultured for 24 hours was selected for subsequent experiments. Compared with blank control group, the activity and mineralization capacity of osteoblasts in CCCP group decreased, the contents of ROS and MDA increased, the activity of SOD decreased, and the apoptosis rate increased. Meanwhile, the relative expressions of BMP-2, RUNX2, and Bcl2 decreased, and the relative expressions of Cleaved-Caspase-3, Nrf2, and Bax increased. The differences were significant (P<0.05). After further VPA treatment, the oxidative stress damage of osteoblasts in VPA+CCCP group was relieved, and the above indexes showed a recovery trend (P<0.05). In VPA+CCCP+ML385 group, the above indexes showed an opposite trend (P<0.05), and the protective effects of VPA were reversed. Conclusion VPA can inhibit the CCCP-induced oxidative stress injury of osteoblasts and promote osteogenesis via Keap1/Nrf2/Are pathway.
Objective To investigate the efficacy of phloretin combined with sodium hyaluronate in preventing postoperative abdominal adhesion formation in rats and its possible mechanisms. Methods Forty rats were randomly divided into five groups, the rats in the sham-operatinon group only underwent open and closed abdominal surgery, and the remaining rats of four groups underwent cecum scratch-and-rub method of modeling to receive different treatments: the rats in the control group and the phloretin group (PHL group) were closed abdominally after modeling, while the rats in the sodium hyaluronate group (HA group) and the phloretin combined with sodium hyaluronate group (PHL+HA group) were closed abdominally by using 2 mL of sodium hyaluronate gel coated with the damaged abdominal wall and the cecum; the postoperative groups treated with phloretin (the PHL and PHL+HA groups) were treated with 2 mL of40 mg/kg phloretin dissolved in 0.5% sodium carboxymethylcellulose by gavage daily, and the rest of the groups were treated with 2 mL of 0.5% sodium carboxymethylcellulose solution by gavage. After general anesthesia, the rats were executed on the 7th day after surgery, and the Nair’s score was used to evaluate the adhesion status of each group on the 7th day after surgery; the adhesive tissue or normal peritoneal tissue were collected (cecum and its opposite side of the peritoneal tissue was collected in the sham-operation group), and immunohistochemistry was performed to evaluate the degree of staining with Nrf2 antibody, HE staining was performed to evaluate the inflammation scores, and Sirius red staining was performed to evaluate the thickness of the collagen fibers, and levels of transforming growth factor β1 (TGF-β1), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. Results All rats successfully completed the experiment. Compared with the control group, Nair’s score, inflammation score, expression level of TGF-β1, thickness of collagen fibers in the adherent tissues, and MDA level were significantly lower in the PHL+HA group (P<0.05), but the SOD level and expression lever of Nrf2 were significantly higher in the PHL+HA group (P<0.05). Conclusion Phloretin combined with sodium hyaluronate can prevent the formation of postoperative abdominal adhesions in the rat model, which may be related to reducing inflammation, reducing collagen deposition, activating Nrf2 pathway and inhibiting oxidative stress.