ObjectiveTo evaluate the influence of nicotine intake on bone microstructure, bone biomechanics, and oxidative stress state in rats. MethodsThirty-six 6-week-old male Sprague Dawley rats (weight, 160-180 g) were randomly divided into control group, low dose group, and high dose group, 12 rats each group. The rats in high dose group and low dose group were given respectively 6.0 mg/kg and 0.4 mg/kg nicotine gavage intervention for 12 months; no intervention was made in the control group. The survival of rats was observed during experiment, and the weight of rats was measured every month. At 12 months after modeling, the L1 vertebral body was harvested to measure the bone mineral density (BMD), bone volume fraction (BVF), trabecular thickness (TT), trabecular number (TN), and trabecular spacing (TS) by Micro-CT three-dimensional reconstruction; the left femur was harvested for biomechanical tests of maximal load, stiffness, and the maximal fracture energy; and arterial blood was extracted to measure the malonyldialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and cotinine. ResultsDuring the experiment, two rats and one rat were added in the high dose group and the low dose group because of death, and no death in the control group. The body weight of the rats in the high and low dose groups gradually decreased with time when compared with one in the control group, and significant difference was found between two dose groups and the control group at 8-12 months (P < 0.05); the body weight of the high dose group was significantly lower than that of the low dose group at 11 and 12 months (P < 0.05). At 12 months after modeling, BMD, BVF, TT, and TN were significantly lower in the high dose group than the control group and the low dose group, but TS was significantly increased (P < 0.05). Difference in BVF, TN, and TS was significant between the low dose group and the control group (P < 0.05). The maximal load, stiffness, and maximal fracture energy of femoral shaft were significantly lower in the high dose group than the control group and the low dose group, and in the low dose group than the control group (P < 0.05). Compared with the control group, the levels of cotinine and MDA were significantly increased, and the levels of CAT and SOD were significantly decreased in the high and low dose groups (P < 0.05), and there were significant differences between the high and low dose groups (P < 0.05). ConclusionNicotine intake can cause micro-structural changes of the bone, decreased bone mechanical properties, and imbalance of oxidation-antioxidant levels in rats. High-dose nicotine intake may be one of the causes of osteoporosis.
ObjectiveTo evaluate the effects of N-acetylcysteine (NAC) on lung tissue of Wistar rats, which were tracheally instilled fine particulate matter (PM2.5).MethodsForty-eight male Wistar rats were randomly divided into six groups: two control groups [they were blank group (C1), fake treatment group (C2) separately], four treatment groups [they were PM2.5 group (P), low-dose NAC group (L), medium-dose NAC group (M), high-dose NAC group (H) separately]. C1 received no treatments at all. C2 was instilled with sterile water (1 ml/kg) tracheally once a week for four times. P was instilled equivoluminal PM2.5 suspension (7.5 mg/kg) tracheally once a week for four times. The NAC groups received gavage (10 ml/kg) of different dosage of NAC (125, 250, 500 mg/kg) for six days. At the seventh day, the NAC groups were instilled PM2.5 suspension (7.5 mg/kg) tracheally. The procedures were repeated for three times in the NAC groups. Twenty-four hours later after four weeks or after the last instilling, all rats were sacrificed. Lung tissue was stained by hematoxylin-eosin (HE) staining, and histopathological changes of lung tissue were observed by optical microscope. The levels of C-reactive protein (CRP) as well as tumor necrosis factor-α (TNF-α) of serum, TNF-α of bronchoalveolar lavage fluid (BALF), TNF-α as well as interleukin-1β (IL-1β) of homogenates of lung tissue were detected by enzyme-linked immunosorbent assay. The activity of lactate dehydrogenase (LDH) as well as the levels of malondialhyde (MDA) of serum and BALF were detected by standard colorimetric method.ResultsHE staining showed that the normal structure of lung were destroyed in the groups dealed with PM2.5 and NAC could alleviate these changes. Higher dosage of NAC seemed to provide more powerful protections. Structure of the lung in C1 as well as C2 were nearly normal. The levels of CRP as well as TNF-α of serum, TNF-α of BALF, TNF-α as well as IL-1β of homogenates of lung tissue in the groups of P, L, M, H were higher than that in the groups of C1, C2 (all P<0.05). The levels of CRP as well as TNF-α of serum, TNF-α of BALF, TNF-α as well as IL-1β of homogenates of lung tissue in the groups of L, M, H which groups received NAC treatments were lower than that in P group. More, the groups seemed to have lower levels of CRP, TNF-α, IL-1β when higher dosage of NAC were given. The activity of LDH as well as the levels of MDA of serum, and BALF in the groups of P, L, M, H were higher than that in the groups of C1, C2 (all P<0.05). The activity of LDH as well as the levels of MDA of serum and BALF in the groups of L, M, H which groups received NAC treatments were lower than that in P group (all P<0.05). ConlusionTo some extent, NAC demonstrate antagonistic effects on oxidative stress and inflammatory injury on rats’ lung brought by PM2.5.
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.
Age-related macular degeneration (AMD) is a multifactorial disease affected by environmental factors and genetic variation, which is a major cause of irreversible vision loss in the elderly. miRNA is a kind of endogenous non-coding RNA, which plays an important role in the pathogenesis of AMD, such as oxidative stress, pathological neovascularization and inflammation, by inhibiting or silencing the expression of transcription genes. miRNA has unique advantages in terms of ease synthesis, targeting and additive effect, a large number of experiments have proved the therapeutic potential of miRNA in AMD, which is expected to become a new method for the treatment of AMD in the future. Since the pathogenesis of AMD has not been fully elucidated, it is still necessary to continue to study the pathogenesis of AMD, the biological effects and mechanisms of various miRNA in the occurrence and development of AMD, and observe its therapeutic effects in AMD, so as to provide more effective options for the precise prevention and treatment of AMD.
ObjectiveExplore the mechanism of action of Kruppel-like factor 4 (KLF4) in the oxidative damage model of hippocampal neurons in mice induced by glutamate. MethodsTo clarify the role of KLF4 and glutamate in the oxidative toxicity of epilepsy, the mouse hippocampal neuron cell line (HT22) was adopted, and a neuronal death excitotoxicity cell model was formed by induction with glutamate as the in vitro epilepsy experimental model. The expression level of KLF4 was detected by Real-Time PCR. HT22 cells were transfected with KLF4-specific siRNA, and the experiments were grouped as follows: Ctrl group, Glu group, Glu + siKLF4-1 group, and Glu + siKLF4-2 group. The cell viability of each group was detected by the CCK8 method. ResultsKLF4 was significantly increased in the epilepsy model of HT22 cells induced by glutamate, while downregulation of KLF4 improved the proliferation and viability of neurons in the epilepsy model of HT22 cells induced by glutamate. ConclusionIn the hippocampal neuron cells of epileptic mice, KLF4 is highly expressed. The downregulation of KLF4 improves the proliferation function and vitality of glutamate-induced HT22 cells, indicating that KLF4 may contribute to the occurrence and development of epilepsy by participating in the regulation of oxidative stress responses.
ObjectiveTo investigate the protective effect of mangiferin on acute spinal cord injury (SCI) in rats and its mechanism. MethodsNinety Sprague Dawley rats were randomly divided into 5 groups, 18 rats in each group. SCI was induced by using the Allen's method (60 g/cm) at T9 level in the rats of groups B, C, D, and E; laminectomy was performed at T8-10 in group A. The rats were injected intraperitoneally with saline in groups A and B, and with mangiferin in groups C (10 mg/kg), D (25 mg/kg), and E (50 mg/kg) every day for 30 days. The survival condition of rats was observed after operation; at 24, 48, and 72 hours after operation, the motor function of the hind limb was evaluated by the Basso, Beattie, Bresnahan (BBB) scores. The spinal cord edema was assessed by measuring the water content in spinal cord tissues at 72 hours. Meanwhile, malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) were detected by ELISA; nuclear factor κB (NF-κB), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 were measured via ELISA at the same time. Caspase-3 and Caspase-9 were also detected by ELISA after mangiferin treatment for 30 days. The expressions of Bax and Bcl-2 proteins were detected by Western blot. Pathological changes of the spinal cord was observed by HE staining. And Caspase-3 protein expression was detected by immunohistochemical staining. ResultsAll rats survived to the end of experiment. BBB scores of groups B, C, D, and E were significantly less than that of group A (P < 0.05), and it showed an increase trend from groups B to E (P < 0.05). The content of water of groups B, C, D, and E were significantly greater than that of group A (P < 0.05), and it showed a decrease trend from groups B to E (P < 0.05). ELISA showed that the activities of MDA, NF-κB, TNF-α, IL-1β, IL-6, Caspase-3, and Caspase-9 in groups B, C, D, and E were significantly greater than that in group A (P < 0.05), and they showed decrease trends from groups B to E (P < 0.05). Meanwhile, the activities of CAT, SOD, and GSH in groups B, C, D, and E were significantly less than that in group A (P < 0.05), and they showed increase trends from groups B to E (P < 0.05). Western blot showed that the relative expression of Bax protein in groups B, C, D, and E were significantly greater than that in group A (P < 0.05), and it showed a decrease trend from groups B to E (P < 0.05). Meanwhile, the relative expression of Bcl-2 protein in groups B, C, D, and E were significantly less than that in group A (P < 0.05), and it showed an increase trend from groups B to E (P < 0.05). Histological observation showed that the pathological changes in group B were accord with that in SCI, and the degree of necrosis in groups C, D, and E were significantly improved when compared with that in group B, and the effect was better in group E than group D, and group D than group C. Immunohistochemical staining showed that the absorbance (A) value of Caspase-3 in groups B, C, D, and E were significantly greater than that in group A (P < 0.05), and it showed a decrease trend from groups B to E (P < 0.05). ConclusionMangiferin has neuroprotective effects on acute SCI in rats by alleviating edema of spinal cord, inhibiting oxidative stress and inflammation response, and regulating the Bcl-2 and Bax pathway.
This study aims to investigate the protective effect of resveratrol against liver injury in hindlimb unloading rats. Thirty 2-month-old male SD rats were randomly divided into normal group (Control), hindlimb unloading model group (Model), and hindlimb unloading+resveratrol administration group (Model+Res). The Model + Res group was injected intraperitoneally with 30 mg/kg of resveratrol, and the Control and Model groups were injected intraperitoneally with an equal volume of 0.9% NaCl. Liver tissues were collected after 28 days and analyzed for oxidative stress, inflammatory factors, energy metabolism indices, Na+-K+-ATPase and Ca2+-Mg2+-ATPase activity, and morphological changes were observed by hematoxylin-eosin staining. The protein expression levels of Bax, Bcl-2, p-PI3K, PI3K, p-AKT, and AKT were detected by Western blotting. Compared with the Control group, hepatocytes in the Model group showed swelling, abnormal morphology, nuclear consolidation, and cell membrane disruption. Oxidative stress, inflammatory factor levels, hepatic glycogen accumulation, and energy metabolism were increased in the liver tissues of the Model group, while resveratrol treatment significantly reversed these changes. The results of Western blotting showed that resveratrol significantly reduced the expression of Bax and increased the expression levels of Bcl-2, and the proteins of p-PI3K/PI3K and p-AKT/AKT expression levels. It is suggested that 28 days of hindlimb unloading treatment could lead to liver tissue injury in rats, which is manifested as oxidative stress, inflammatory response, energy metabolism disorder and increased apoptosis level, and resveratrol has a certain mitigating effect on this.
Objective To evaluate the expression of reactive oxygen species (ROS), glutataione (GSH), total superoxide dismutase (T-SOD), total antioxidation capacity (T-AOC), thioredoxin reductase (TrxR) under the intervention of hedysarum polysaccharides-1 (HPS-1) in A549 cells. Methods After treated by HPS-1 in different doses (50 mg/L, 100 mg/L, 200 mg/L, respectively), the viability of cell lines was detected by MTT method under microscope. The apoptosis of cell lines was detected by flow cytometry (FCM). The expressions of ROS, GSH, T-SOD, T-AOC, and TrxR in cell supernatant were measured by chemiluminescence method. Results Determined by MTT/FCM/ELISA, the results showed that different doses of HPS-1 could inhibit the proliferation and promote the apoptosis of A549 cells (allP<0.05). The expression levels of GSH, T-SOD, T-AOC, and TrxR were significantly decreased (allP<0.05) and the expression levels of ROS and MDA were significantly increased (allP<0.05) in a concentration-dependent manner in A549 cells treated with HPS-1, and these effects were significantly weakened in A549 cells with time extending (allP<0.05). Conclusion HPS-1 has a markedly effect on inhibiting cellular proliferation and inducing cellular apoptosis of lung adenocarcinoma A549 cells, which may be associated with the change of oxidation/antioxidant.
Age-related macular degeneration (AMD) is one of the leading irreversible causes of blindness in China. The pathogenesis of AMD is not fully understood at present. Under various stress conditions, cellular senescence is activated, characterized by telomere shortening, mitochondrial dysfunction, DNA damage, and the release of various senescence-related secretory phenotype factors. Senescence is implicated in the pathogenesis of AMD through multiple pathways, contributing to chronic inflammation and the onset and progression of AMD. Mechanisms such as oxidative stress, lipofuscin, β amyloid protein and the membrane attack complex have become hotspots of study in the pathogenesis of AMD. The cyclic guanosine phosphate - adenosine synthase - interferon stimulating factor synthase-stimulator of interferon gene pathway has emerged as a critical signaling pathway in the early development of AMD, providing direction for further research on AMD. Currently, senolytics, selective agents targeting the induction of senescent cell apoptosis, show significant potential in the treatment of AMD. The integration of new technologies with cellular senescence may offer a novel approach to AMD treatment, and intervening in the AMD treatment through anti-cellular senescence pathways holds promising prospects.
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.