ObjectiveTo establish a cell inflammation model induced by tumor necrosis factor-α (TNF-α) in human bronchus epithelial cells, and investigate the effects of glutathione S-transferase mu 5 (GSTM5) on the inflammation and oxidative stress.
Methods16HBE cells were treated with TNF-α (10 ng/mL, 24 h) in the absence or presence of the constructed GSTM5 eukaryotic expression vector (1 μg/mL). The concentration of malondialdehyde (MDA) and total antioxidation capacity (T-AOC) were detected by colorimetric method. The survival rate of cells was assessed by the methyl thiazolyl tetrazolium (MTT) assay. The transcription level of NADPH oxidase-1 (NOX1), NOX2, NOX3, NOX4, NOX5, dual oxidase-1 (DUOX1) and DUOX2 were evaluated by RT-PCR. Western blot was performed to investigate the protein levels of NOX1 and NOX2.
ResultsTNF-α simulation significantly increased the level of MDA in cells, and decreased the level of T-AOC and survival rate of 16HBE. When transfected with the GSTM5 eukaryotic expression vector, the concentration of MDA significantly decreased (P < 0.05), and the activation of T-AOC increased dramatically (P < 0.05). Consequently, the survival rate of 16HBE in the GSTM5 group improved (P < 0.05). The 16HBE cells transfected with the constructed GSTM5 eukaryotic expression vector had a lower transcription and protein levels of NOX1 and NOX2 (all P < 0.01). There were no significant changes in the mRNA expressions of NOX3, NOX4, NOX5, DUOX1 or DUOX2.
ConclusionGSTM5 may down-regulate the transcription level of NOX1 and NOX2 to reduce the inflammation and oxidative stress induced by TNF-α.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.
Objective To observe the effects of cigarette smoke extract ( CSE) on the proliferation and secretion of hydrogen peroxide ( H2O2 ) in human lung fibroblasts ( HLFs) induced by transforming growth factor-β1 ( TGF-β1 ) . Methods Cultured HLFs were divided into a normal group and a model group induced by TGF-β1 ( 5 ng/mL) , then intervened with CSE at different concentrations ( 0% , 2. 5% , 5% ,10% , respectively) . Brdu ELISA assay was used to detect cell proliferation. H2O2 release from cultured cells was assayed using a fluorimetric method. Cellular localization of H2O2 and expression of α-SMA were performed using a fluorescent-labeling strategy. Results TGF-β1 stimulated group showed positive expression of α-SMA, implying TGF-β1 had induced fibroblasts to differentiate into myofibroblasts. In TGF-β1 stimulated group, 2. 5% and 5% CSE promoted cell proliferation ( P lt; 0. 01 or 0. 05) , while 10% CSE inhibited cell proliferation ( P lt; 0. 01) . In the normal group, both low and high concentration of CSE inhibited cell proliferation ( P lt; 0. 01 or P lt; 0. 05) , and the inhibition effect was dose-dependent. HLF induced by TGF-β1 generated low constitutive levels of extracellular H2O2 that was markedly enhanced by CSE treatment ( P lt; 0. 01) . Pretreatment with DPI, an inhibitor of NADPH oxidase, abolished secretion of H2O2 . Cellular localization of H2O2 by a fluorescent-labeling strategy demonstrated that extracellular secretion of H2O2 is specific to the myofibroblast. Conclusions Low concentration of CSE can promote myofibroblast proliferation, and markedly increase extracellular secretion of H2O2 . CSE possibly take part in the development and progress of idiopathic pulmonary fibrosis by increasing oxidative stress.
ObjectiveTo explore the effect of H2O2-actived RAW264.7 macrophages on the migration, proliferation, and osteogenesis gene expression of MC3T3-E1 in mice.
MethodsMC3T3-E1 cells and RAW264.7 cells were cultured to the 7th generation. RAW264.7 macrophages were stimulated with 0, 25, 50 and 100 μmol/L H2O2, the cell proliferation rate was detected by MTS at 1, 3, and 6 hours after stimulated, and superoxide dismutase (SOD) content by SOD assay kit at 1 hour after stimulated. The appropriate concentration and action time of H2O2-actived RAW264.7 were obtained. The supernatant of RAW264.7 macrophages stimulated by H2O2 or not was collected at 24 hours. Then, the supernatant was used to culture MC3T3-E1 cells in groups B (not stimulated by H2O2) and C (stimulated by H2O2), and DMEM was used as a control in group A. The migration of MC3T3-E1 cells was detected at 12 and 24 hours by cell scratch test, the proliferation of MC3T3-E1 cells at 24, 48, and 72 hours by MTS assay. MC3T3-E1 cells were cultured with only complete medium in blank control group, with complete medium containing 50 μg/mL vitamin C + 10 nmol/L β sodium glycerophosphate in positive group, normal control group (adding the supernatant not stimulated by H2O2), and experimental group (adding the supernatant stimulated by H2O2). At 3, 7, and 14 days, RT-PCR was used to determine the osteogenesis related mRNA expressions of alkaline phosphatase (ALP), Runx2, osteopontin (OPN), osteocalcin (OC), bone sialoprotein (BSP), and collagen type I (COL-I).
ResultsThe results of MTS and SOD assay showed that the appropriate concentration and action time of H2O2-actived RAW264.7 macrophages were 25 μmol/L and 1 hour, respectively. MTS assay showed that the proliferation rate of MC3T3-E1 cells was significant higher in groups B and C than group A (P < 0.05), in group B than group C, and significant difference was shown between groups at 2 and 3 days (P < 0.05). The cell scratch test indicated that the migration of MC3T3-E1 cells was significantly faster in groups B and C than group A, and in group C than group B at 12 hours (P < 0.05); many migrated cells were observed in all scratch sites of groups B and C at 24 hours. When compared with positive control group, the mRNA expressions of ALP, Runx2, OC and BSP in experimental group were significantly down-regulated at 7 and 14 days (P < 0.05). When compared blank control group, the mRNA expressions of OPN and COL-I in experimental group were significantly down-regulated at 7 and 14 days (P < 0.05).
ConclusionThe appropriate concentration and action time of H2O2-actived RAW264.7 macrophages are 25 μmol/L and 1 hour. The H2O2-actived RAW264.7 cells can promote MC3T3-E1 cells migration, and suppress MC3T3-E1 cells proliferation and expressions of osteogenesis related genes.
ObjectiveTo detect the level of oxidative stress markers in serum, including malondialdehyde (MDA), protein carbonyls (PC), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and total antioxidant capacity (TAC), in patients with stable chronic obstructive pulmonary disease (COPD), and explore the impacts of oxidant/antioxidant imbalance in pathogenesis of COPD.
MethodsTwo hundred stable COPD patients (the COPD group) and 100 healthy individuals (the control group) were recruited in the study. The concentrations of MDA, PC, 8-OHdG and TAC in serum were detected. Pulmonary function test was performed and the general informations for each subjects were collected. The COPD patients were divided into a smoking subgroup and a non-smoking subgroup, or divided into a mild-moderate airflow limitation subgroup and a severe-extremely severe airflow limitation subgroup.
ResultsThe levels of serum MDA, PC and 8-OHdG in the COPD group were significantly higher than those in the control group (all P < 0.01), but the level of serum TAC was significantly lower than that in the control group (P < 0.01). In the COPD patients, the levels of PC and 8-OHdG in the smoking subgroup were significantly higher than those in the non-smoking subgroup (both P < 0.05). The level of PC in the severe-extremely severe airflow limitation subgroup was significantly higher when compared with the mild-moderate airflow limitation subgroup (P < 0.01). Multiple linear regression analysis showed that the levels of PC and 8-OHdG were negatively related with FEV1% pred in the COPD patients, and the PC had greater impacts than 8-OHdG (β=-0.230, -0.219, P < 0.01).
ConclusionSmoking can induce the abnormal increase of PC and 8-OHdG in serum which are negatively related with FEV1% pred in COPD patients, which suggests that oxidative stress might play an important role in pathogenesis of COPD.
MiRNAs are stable small RNAs that are expressed abundantly in animals and plants. They can bind to the 3'-untranslated region of the target mRNA, and regulate its expression at the post-transcriptional level. The miRNAs’ abnormal expression and its following abnormal biological regulation are closely related to the occurrence and development of age-related macular degeneration (AMD), including inflammatory response, oxidative stress injury, phagocytosis dysfunction and abnormal angiogenesis. Since the dysregulation of miR-155, miR-125b and miR-34a seems to play a more important role in AMD, these microRNAs may be expected to become the new biomarkers and therapeutic targets for AMD.
ObjectiveTo investigate the protective effects of carboxymethylated chitosan (CMCS) on oxidative stress induced apoptosis of Schwann cells (SCs), and the expressions of brain derived neurotrophic factor (BDNF) and gl ial cell line derived neurotrophic factor (GDNF) in oxidative stress induced SCs.
MethodsTwenty-four 3-5 days old Sprague Dawley rats (weighing 25-30 g, male or female) were involved in this study. The bilateral sciatic nerves of rats were harvested and SCs were isolated and cultured in vitro. The purity of SCs was identified by immunofluorescence staining of S-100. SCs were treated with different concentrations of hydrogen peroxide (H2O2, 0.01, 0.10, and 1.00 mmol/L) for 3, 6, 12, and 24 hours to establ ish the apoptotic model. The cell counting kit 8 (CCK-8) and flow cytometry analysis were used to detect the cell viabil ity and apoptosis induced by H2O2, and the optimal concentration and time for the apoptotic model of SCs were determined. The 2nd passage SCs were divided into 5 groups and were treated with PBS (control), with 1.00 mmol/L H2O2, with 1.00 mmol/L H2O2+50 μg/mL CMCS, with 1.00 mmol/L H2O2+100 μg/mL CMCS, and with 1.00 mmol/L H2O2+200 μg/mL CMCS, respectively. After cultured for 24 hours, the cell viabil ity was assessed by CCK-8, cell apoptosis was detected by flow cytometry analysis, the expressions of mRNA and protein of BDNF and GDNF were detected by real-time quantitative PCR and Western blot.
ResultsThe immunofluorescence staining of S-100 indicated the positive rate was more than 95%. CCK-8 and flow cytometry results showed that H2O2 can inhibit the proliferation of SCs and induce the SCs apoptosis with dose dependent manner, the effect was the most significant at 1.00 mmol/L H2O2 for 24 hours; after addition of CMCS, SCs exhibited the increased proliferation and decreased apoptosis in a dose dependent manner. Real-time quantitative PCR and Western blot analysis showed that 1.00 mmol/L H2O2 can significantly inhibit BDNF and GDNF expression in SCs when compared with control group (P<0.05), 50-200 μg/mL CMCS can reverse the oxidative stress-induced BDNF and GDNF expression in SCs in a dose dependent manner, showing significant difference compared with control group and 1.00 mmol/L H2O2 induced group (P<0.05). There were significant differences among different CMCS treated groups (P<0.05).
ConclusionCMCS has the protective stress on oxidative stress induced apoptosis of SCs, and may promote the BDNF and GDNF expressions of neurotrophic factors in oxidative stress induced SCs.
Objective To observe and preliminarily explore the effect of mogroside on oxidative stress of retinal pigment epitheliaum (RPE) cells induced by hydrogen peroxide (H2O2) and its possible mechanism. MethodsA experimental study. The RPE cells were divided into control group, H2O2 group, silent information regulator of transcription 1 (SIRT1) inhibitor EX527 group (EX527 group), mogroside group, mogroside+EX527 group. Methyl thiazolete trazolium method was used to detect cell survival rate. Flow cytometry was used to detect cell apoptosis rate. 2',7'-dichlorodihydrofluorescein diacetate fluorescent probe method, xanthine method and enzyme-linked immunosorbent assay method were used to detect the level of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in cells respectively. Real-time quantitative polymerase chain reaction and Western blot were used to detect relative expressions of SIRT1, nuclear factor erythroid-2-related actor 2 (Nrf2), heme oxygenase-1 (HO-1) mRNA and protein in cells. One-way ANOVA was used for comparison among groups. The pairwise comparison between groups was tested by the least significant difference t test. Results Compared with the control group, the H2O2 group cell survival rate decreased, the apoptosis rate increased, the ROS level in the cells increased, the SOD activity decreased, the MDA content increased, and the relative expression of SIRT1, Nrf2, HO-1 mRNA and protein decreased (P＜0.05). Compared with H2O2 group, the cell survival rate decreased, apoptosis rate increased, the cell ROS level increased, SOD activity decreased, MDA content increased, SIRT1, Nrf2, HO-1 mRNA and protein expression decreased in EX527 group (P＜0.05); the cell survival rate increased, apoptosis rate decreased, ROS level decreased, SOD activity increased, MDA content decreased, and the relative expression of SIRT1, Nrf2, HO-1 mRNA and protein increased in mogroside group (P＜0.05). Compared with the mogrosides group, the cell survival rate decreased, the apoptosis rate increased, the level of ROS increased, SOD activity decreased, MDA content increased, SIRT1, Nrf2, HO-1 mRNA and protein decreased in mogrosides+EX527 group (P＜0.05). ConclusionsMogrosides can alleviate the oxidative stress response of visual RPE cells induced by H2O2, promote cell proliferation, and reduce cell apoptosis. Mogrosides may exert antioxidant effects by activating the SIRT1/Nrf2 signaling pathway.
ObjectiveTo study the effects of the new small molecular oxygen free radical scavenger Tempol on the survival and vasculogenesis of the long random pattern skin flap (LRPSF) and its mechanism.
MethodsEighty-four male Sprague Dawley rats were randomly divided into control and Tempol groups (42 rats in each group). LRPSF of 9 cm×3 cm in size were prepared on the backs of rats in two groups based on the Mcfarlane flap. Rats were administered with Tempol (100 mg/kg) in the Tempol group and with normal saline in the control group by intraperitoneal injection at 15 minutes before operation and at 1-7 day after operation. The rat and the skin flap survival conditions were observed after operation; the survival rate of skin flap was measured, and the vascular structure, vascular volume, and total length of blood vessels were analyzed with Micro-CT three-dimensional imaging after 7 days; HE staining was used to observe the structure of the skin flaps and inflammation, immumohistochemical staining to observe vascular endothelial growth factor (VEGF) expression; water-soluble tetrazolium-1 method was used to measure the content of superoxide dismutase (SOD) and malondialdehyde (MDA), and ELISA to detect the expressions of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) after 1, 3, and 7 days.
ResultsAll of rats survived after operation, without hemorrhage, edema, and infection. With the extension of time, necrosis occurred in the distal part of the skin flaps in 2 groups, but the necrosis degree of the Tempol group was lower than that of control group; meanwhile, the blood vessel distribution and continuity were better than those of control group. The skin flaps survival rate, vascular volume, and total length of blood vessels of Tempol group were significantly higher than those of control group after 7 days (P<0.05). The clearer skin flaps structure, lighter inflammation reaction and inflammation cell infiltration, and higher VEGF staining intensity were observed in the Tempol group than the control group after 7 days. There was no significant difference in SOD, MDA, and TNF-α, and IL-6 contents between the 2 groups at immediate after operation. SOD significantly increased, but MDA, TNF-α, and IL-6 contents significantly decreased in the Tempol group when compared with control group after 1, 3, and 7 days (P<0.05).
ConclusionTempol can significantly promote the LRPSF survival rates, its mechanism is closely related to the promotion of vasculogenesis and reduction of oxidative stress and inflammation.
Metabolic memory means if the hyperglycemia can't be controlled at early stage of diabetes, chronic complications such as diabetic retinopathy (DR) will continue to develop even if the blood glucose level maintains normal level at later stage. Oxidative stress plays an important role in the "metabolic memory" of DR, which interacts with the nitrative stress, advanced glycation end products, genetic modification and endoplasmic reticulum stress in the pathogenesis of DR. Further elucidation of the relationship between oxidative stress and "metabolic memory" of DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
