Objective To investigate the effects of adenosine 2A receptor (A2AR) activation on oxidative stress in small-forsize liver transplantation. Methods A rat orthotopic liver transplantation model was performed using 40% graft, 18 recipients were given intravenously saline (control group), CGS21680 (A2AR agonist, CGS21680 group) or ZM241385 (A2AR antagonist, CGS21680+ZM241385 group) randomly. Aspartate aminotransferase (AST), enzymatic antioxidants 〔superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase (GSH-Px)〕, non-enzymatic antioxidants 〔ascorbic acid (AA); glutathione (GSH); α-tocopherol (TOC)〕 and lipid oxidant metabolites malondialdehyde (MDA) were measured and analyzed at 6 h after reperfusion. Results Compared with the control group and CGS21680+ZM241385 group, A2AR activation increased the activities of SOD and GSHPx (Plt;0.05), reduced the productions of AST and MDA (Plt;0.05), increased the levels of AA, GSH and TOC (Plt;0.05) in CGS21680 group. But there was no significant change in CAT activity (Pgt;0.05) among 3 groups. Conclusions A2AR activation improves the antioxidant enzyme activities, promotes the production of antioxidants, and slowes down the increase in MDA level, depresses of the increase in AST activity. A2AR activation suppresses oxidative damage and increases the antioxidant capacity which in turn minimizes their harmful effects of ischemia-reperfusion in small-for-size liver transplantation.
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 observe the protective effect of dl-3-n-Butylphthalide (NBP) on apoptosis of retinal Müller cells induced by hydrogen peroxide (H2O2).MethodsHuman retinal Müller cells cultured in vitro were divided into normal control group, model group (H2O2 group) and experimental group (H2O2+NBP group). The cells in the H2O2 group and H2O2+NBP group were cultured with 200 μmol/L H2O2 for 2 h. Then the culture solution of the H2O2 group replace with complete medium and the H2O2+NBP group replace with complete medium containing 1 μmol/L NBP. The normal control group was a conventional cultured cells. Müller cells were identified by immunofluorescence staining. Hematoxylin-eosin (HE) staining was used to observe the apoptosis morphological changes. MTT assay was used to detect the activity of of retinal Müller cells after after 24 h and 48 h of NBP intervention. Hoechst33258 staining was used to observe the apoptosis. LIVE/DEAD ® cell activity/cytotoxicity kit was used to detect cell viability. Dichlorofluorescein diacetate (DCFH-DA) + endoplasmic reticulum (ER) red fluorescent probe (ER-Tracker Red) double staining was used to observe the expression level of reactive oxygen species (ROS) in ER of cells. One-way ANOVA combined with Dunnett statistical method were used for data analysis.ResultsHE staining showed that the number of cells in H2O2+NBP group was higher than that in H2O2 group. MTT assay showed that after 24 h and 48 h of NBP intervention, the differences in cell viability between the normal control group and the H2O2 group, the H2O2 group and the H2O2+NBP group were statistically significant (t=28.96, 3.658, 47.58, 20.33; P＜0.001, 0.022). The results of Hoechst33258 showed that the nuclear nucleus of a few cells in the H2O2+NBP group was crescent-shaped and the nuclear fragmentation was reduced, and the blue fluorescence of the remaining cells was uniform. The LIVE/DEAD ® cell activity/cytotoxicity kit showed that the number of dead cells with red fluorescence in the H2O2 group increased significantly, and the number of viable cells with green fluorescence decreased significantly. In the H2O2+NBP group, the number of viable cells with green fluorescence increased, and the number of dead cells with red fluorescence decreased. The double staining results of DCFH-DA+ER-Tracker Red showed that the green fluorescence intensity of H2O2 group was significantly enhanced; the green fluorescence intensity of H2O2+NBP group was lower than that of H2O2 group.ConclusionNBP alleviates H2O2-induced apoptosis of human retinal Müller cells by inhibiting ROS production.
Objective To investigate the implication of oxidation protein product ( advanced oxidation protein product, AOPP) , an index of oxidative stress in obstructive sleep apnea-hypopnea syndrome ( OSAHS) . Methods 47 patients with OSAHS and 48 normal controls were enrolled. The concentration of AOPP was measured by spextrophotometry after ameliorated, while superoxide ( SOD) , malonaldehyde ( MDA) , glutathione peroxidase ( GSH-PX) in morning blood samples were detected by Xanthine oxidase test. Results ( 1) Plasma AOPP and MDA were significantly elevated in OSAHS compared with those in control group ( both P lt;0. 01) . Plasma SOD and GSH-PX were significantly lower in OSAHS compared with those in control group ( both P lt;0. 01) . There were significant differences in the plasma AOPP, MDA, SODand GSH-PX among different severity of OSAHS ( all P lt; 0. 01) . Plasma AOPP and MDA were increased and SOD and GSH-PX were gradually decreased with the progression of OSAHS. ( 2) Plasma AOPP correlated well with MDA, SOD and GSH-PX, moreover, AOPP was positively correlated with apnea hyponea index or lowest oxygen saturation. Conclusion AOPP is an alternative index reflecting both oxidative streess and tissue injury in patients with OSAHS.
Objective Bone marrow mesenchymal stem cells (BMSCs) transplantation can potentially regenerate the degenerated intervertebral disc, with the underlying regenerating mechanism remaining largely unknown. To investigate the potential of human BMSCs protecting nucleus pulposus cells (NPCs) from oxidative stress-induced apoptosis in a coculturesystem, and to illustrate the possible mechanisms of BMSCs transplantation for intervertebral disc regeneration. Methods BMSCs collected by density gradient centrifugation in Percoll solution were cultured and sub-cultured till passage 3, and the surface molecules of CD34, CD45, and CD13 were identified. NPCs were isolated by collagenase digestion and the chondrocyte l ike phenotype was confirmed by morphologic observation after HE staining, inverted phase contrast microscope, proteoglycan, and collagen type II expression after toluidine blue and immunocytochemistry staining. The 3rd passage BMSCs and the 1st passage NPCs were divided into four groups: group A, NPCs (1 × 106 cells) were cultured alone without apoptosis inducing (negative control); group B, NPCs (1 × 106 cells) were co-cultured with BMSCs (1 × 106 cells) with apoptosis inducing; group C, NPCs (1 × 106 cells) were co-cultured with BMSCs (3 × 105 cells) with apoptosis inducing; group D, NPCs (1 × 106 cells) were cultured alone with apoptosis inducing (positive control). After 3 or 7 days of culture or co-culture, the NPCs in groups B, C, and D were exposed to 0.1 mmol hydrogen peroxide for 20 minutes to induce apoptosis. With DAPI staining cellular nucleus, Annexin-V/propidium iodide staining cellular membrane for flow cytometry analysis, the apoptosis of NPCs in each group was studied both qual itatively and quantitatively. Besides, the changes in Bax/Bcl-2 gene transcription and Caspase-3 protein content, were analyzed with semi-quantitative RT-PCR and Western blot. Results BMSCs were successfully isolated and CD34-, CD45-, and CD13+ were demonstrated; after isolated from degenerated intervertebral discs and sub-cultured, the spindle-shaped 1st passage NPCs maintained chondrocyte phenotype with the constructive expressions of proteoglycan and collagen type II in cytoplasm. DAPI staining showed the nucleus shrinkage of apoptosis NPCs. Co-cultured with BMSCs for 3 days and 7 days, the apoptosis rates of NPCs in groups B (29.26% ± 8.90% and 18.03% ± 2.25%) and C (37.10% ± 3.28% and 13.93% ± 1.25%) were lower than that in group D (54.90% ± 5.97% and 26.97% ± 3.10%), but higher than that of groupA (15.67% ± 1.74% and 8.87% ± 0.15%); all showing significant differences (P lt; 0.05). Besides, semi-quantitative RT-PCR showed Bcl-2 gene transcription up-regulated (P lt; 0.05) and no significant change of Bax (P gt; 0.05); Western blot result showed that the Caspase-3 protein expression of groups B and C was lower than that of group D, and was higher than that of group A; all showing significant differences (P lt; 0.05). Conclusion In a co-culture system without direct cellular interactions, the oxidative stress-induced apoptosis of human NPCs was amel iorated by BMSCs. The enhanced anti-apoptosis abil ity of NPCs preconditioned by co-culturing with BMSCs might come from the decreased Bax/Bcl-2 gene transcription ratio.
Diabetic retinopathy (DR) constitutes a major retinal vascular disorder leading to blindness in adults. Current therapeutic approaches for DR exhibit certain degrees of efficacy but are constrained by a spectrum of limitations. Hence, there is a pressing need to deeply investigate the underlying pathogenesis of DR and explore novel therapeutic targets. Ferroptosis, a distinctive form of programmed cell death, has emerged as a pertinent phenomenon in recent years. Notably, ferroptosis has been implicated in the progression of DR through mechanisms involving the induction of retinal oxidative stress, provocation of anomalous retinal vascular alterations, exacerbation of retinal neural damage, and elicitation of immune dysregulation. Thus, elucidating the mechanistic role of ferroptosis in DR holds the potential to establish a robust foundational rationale. This could potentially facilitate the clinical translation of ferroptosis inhibitors as promising agents for the prevention and treatment of DR, thereby forging novel avenues in the landscape of DR management.
Objective To investigate the effects of curcumin on oxidative stress in the co-culture system including human fetal lung fibroblasts and A549 cells, and discuss the potential and protective mechanism of the prophylactic effect of curcumin on pulmonary fibrosis. Methods The human fetal lung fibroblasts co-cultured with A549 cells were divided into five groups. The cells in the control group were cultured in DMEM without TGF-β1 or curcumin. The cells in the TGF-β1 group were cultured in DMEM containing 5 ng/mL TGF-β1 . In three TGF-β1 + cucurmin treatment groups, the cells were cultured in DMEM containing 5 ng/mL TGF-β1 and three different concentration of curcumin( 5, 10, 20 μmol /L, respectively) . ELISA was used to analyze the content of TNF-α. Serum level of MDA and SOD were tested by spectrophotometric analysis. Intracellular ROS production was detected by flow cytometry. NF-κB was measured by western blot. Results The serum MDA, intracellular ROS, the content of TNF-αand NF-κB protein expression in the TGF-β1 group were significantly increased while the activity of SOD was significantly decreased( P lt; 0. 01) , suggesting that the oxidative level of human fetal lung fibroblasts was obviously increased after TGF-β1 stimulation. After intervening by different concentration of curcumin, the serum MDA, intracellular ROS, content of TNF-αand NF-κB were significantly decreased while the activity of SOD was obviously increased( P lt;0.01) . Conclusion Low concentration of curcumin can reduce the oxidative level of human fetal lung fibroblasts co-cultured with A549 after TGF-β1 stimulation, and significantly increase the level of SOD, implying that curcumin may intervene pulmonary fibrosis by reduce oxidative level.
ObjectiveTo investigate the effect of α-lipoic acid on the oxidative stress of wound tissues and diabetic wound healing in mice with diabetic feet. MethodsSixty male C57BL/6J mice weighting 200-300 g were randomly divided into model group (control group, n=15), α-lipoic acid-treated model group (n=15), miR-29b mimic group (n=15), and miR-29b mimic negative control group (NC group, n=15). All animals received intraperitoneal injection of streptozocin to establish the diabetic model. Then, a full thickness wound of 5 mm×2 mm in size was created at 4 weeks after modeling. All mice were administrated with high-sugar-fat-diet. At the same day after modeling, α-lipoic acid-treated model group was continuously given intravenous injection of 100 mg/(kg·d) α-lipoic acid for 14 days; miR-29b mimic group and NC group received the tail intravenous injection of lentiviral vector for miR-29b mimic and miR-29b mimic negative control (a total of 2×107 TU), respectively, with the treatment of α-lipoic acid. The wound healing was observed and wound area was measured at 7 and 14 days. The wound tissues were harvested to detect the levels of superoxide dismutase (SOD) and glutathione (GSH) using xanthine oxidase method and 5, 5-dithiobis-2-nitrobenzoic acid staining method at 14 days. At the same day, 7, and 14 days after modeling, the relative miR-29b expression in wound tissues from control and α-lipoic acid-treated model groups was detected by real-time fluorescence quantitative PCR. ResultsAll mice survived to the experiment end. The wound healing was faster in α-lipoic acid-treated group than control group. At 7 and 14 days, the relative wound area and miR-29b expression level were significantly lower, while the contents of SOD and GSH were significantly higher in α-lipoic acid-treated group than control group (P < 0.05). In addition, miR-29b mimic group had significantly increased relative wound area and significantly decreased the contents of SOD and GSH when compared with NC group at 7 and 14 days (P < 0.05). Conclusionα-lipoic acid could inhibit oxidative stress and promote diabetic wound healing by suppressing expression of miR-29b in mice.
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.
ObjectiveTo investigate the effects of MK-801 on antioxidant system activity in the central nervous system of rats with obstructive jaundice. MethodsTwenty rats were divided into four groups: sham operation group, control group, MK-801 low dose group, and MK-801 high dose group. The control group, MK-801 low dose group, and MK-801 high dose group were the obstructive jaundice model groups (OJ groups). From the first day after operation, MK-801 low dose group were processed intraperitoneal injection of MK-801 0.025 mg/(kg·d) and MK-801 high dose group were processed intraperitoneal injection of MK-801 0.25 mg/(kg·d). Meanwhile, sham operation group and control group were injected the same volume of normal saline everyday for 10 days. Three days after operation, rats' tail vein blood were collected for examining the direct bilirubin DBIL) and total bile acids (TBA) in order to determine whether the model were successfully established. And malondialdehyde (MDA), catalase (CAT), total superoxide dismutase (T-SOD), and total antioxidant capacity (T-AOC) were determined on the 10th day to evaluate the oxdative status of the rats. Results①Obstructive jaundice model was established successfully.②The content of MDA in control group, MK-801 low dose group and MK-801 high dose group were significantly increased than the sham operation group, and there was statistical difference (P < 0.05). The content of MDA decreased in MK-801groups compared with the control group (P < 0.05).③Compared with the sham operation group, the activity of CAT in control group decreased significantly (P < 0.05). The activity of CAT in the MK-801 groups increased compared with the control group with significant difference (P < 0.05). There was no statistical difference on the activity of CAT between MK-801 low dose group and high dose group (P > 0.05).④Compared with sham operation group, the activity of T-SOD was decreased significantly in control group with statistical significance (P < 0.05). The activity of T-SOD were increased in the MK-801 groups compared with control group with significant difference (P < 0.05), but the activity of T-SOD was decreased significantly in the high dose group than the low dose group (P < 0.05).⑤In the Oj groups, the T-AOC were significantly increased compared with the sham operation group, and there was statistical significance (P < 0.05). The T-AOC in MK-801 groups were increased compared with the control group with statistical significance (P < 0.05), but there was no statistical difference between the MK-801 groups. Conciusions Oxidative stress exists when obstructive jaundice occurs, and obstructive jaundice can aggravate the oxidative stress damage in the rats' central nervous system and cause increasing expression of enzymes such as CAT which enhance antioxidant capacity of the whole body. MK-801 can decrease lipid peroxidation, and increase activity of CAT and SOD as well as T-AOC in CNS of jaundice rats. But High dose of MK-801 has no better effect than low dose of MK-801. On the contrary, activity of T-SOD decrease in the high dose group than in the low dose group. Further research is needed on the specific mechanism.