Manganese Superoxide Dismutase Levels Research Articles

Extracellular vesicles derived from human umbilical cord mesenchymal stem cells alleviate rat hepatic ischemia‐reperfusion injury by suppressing oxidative stress and neutrophil inflammatory response

Mesenchymal stem cells (MSCs) have been reported to exert therapeutic effects on immunoregulation, tissue repair, and regeneration from the bench to the bedside. Increasing evidence demonstrates that extracellular vesicles (EVs) derived from MSCs could contribute to these effects and are considered as a potential replacement for stem cell-based therapies. However, the efficacy and underlying mechanisms of EV-based treatment in hepatic ischemia-reperfusion injury (IRI) remain unclear. Here, we demonstrated that human umbilical cord MSC-EVs (huc-MSC-EVs) could protect against IRI-induced hepatic apoptosis by reducing the infiltration of neutrophils and alleviating oxidative stress in hepatic tissue in vivo. Meanwhile, huc-MSC-EVs reduced the respiratory burst of neutrophils and prevented hepatocytes from oxidative stress-induced cell death in vitro. Interestingly, we found that the mitochondria-located antioxidant enzyme, manganese superoxide dismutase (MnSOD), was encapsulated in huc-MSC-EVs and reduced oxidative stress in the hepatic IRI model. Knockdown of MnSOD in huc-MSCs decreased the level of MnSOD in huc-MSC-EVs and attenuated the antiapoptotic and antioxidant capacities of huc-MSC-EVs, which could be partially rescued by MnSOD mimetic manganese (III) 5,10,15,20-tetrakis (4-benzoic acid) porphyrin (MnTBAP). In summary, these findings provide new clues to reveal the therapeutic effects of huc-MSC-EVs on hepatic IRI and evaluate their preclinical application.-Yao, J., Zheng, J., Cai, J., Zeng, K., Zhou, C., Zhang, J., Li, S., Li, H., Chen, L., He, L., Chen, H., Fu, H., Zhang, Q., Chen, G., Yang, Y., Zhang, Y. Extracellular vesicles derived from human umbilical cord mesenchymal stem cells alleviate rat hepatic ischemia-reperfusion injury by suppressing oxidative stress and neutrophil inflammatory response.

Dynamics of expression of antibacterial and antioxidant defence genes in Indian major carp, Labeo rohita in response to Aeromonas hydrophila infection

Cells produce large number of antioxidant molecules to prevent reactive oxygen species-induced self-damage during microbial assault while generating simultaneously number of antimicrobial molecules to target the pathogen. The present study was aimed at looking into molecules involved in antibacterial and self-protection mechanism of a host Labeo rohita when challenged with a pathogenic bacterium Aeromonas hydrophila. Expression profiles of few of the important host antibacterial genes viz., inducible nitric oxide synthase (iNOS), lysozyme G (LysoG), apolipoprotein A-I (ApoA-I) and hepcidin, and self-defence anti-oxidant genes viz., manganese superoxide dismutase (MnSOD), catalase and glutathione peroxidases (GPx3) were examined in skin and muscle tissues of bacteria challenged fish. Transcription levels of iNOS, LysoG, ApoA-I, hepcidin, catalase, GPx3 and MnSOD were significantly upregulated (P < 0.05) in both tissues at different time points post-bacterial challenge. Increased expression of antibacterial genes in the muscle and skin clearly explains strong defensive mechanism activated in fish tissues in terms of both oxygen-dependent (iNOS) and independent (lysozyme) ways of microbe reduction, and bacterial lysis via production of antimicrobial molecules (ApoA-I and hepcidin) in the host. Simultaneous upregulation of MnSOD, GPx3 and catalase genes explains their involvement in patrolling the cells with regulated production of reactive oxygen species and keeping at a safe level to protect the host's own cells from oxidative damage.

Expression of antioxidant-related genes in flavedo of cold-stored grapefruit (Citrus paradisi Macfad cv. Rio Red) treated with pectic oligosaccharides

Cold storage is one of the main postharvest technologies for fruit preservation, however, cold-sensitive citrus fruits develop peel physiological alterations affecting external quality known as chilling injury (CI). An efficient antioxidant system has been associated to an enhanced cold stress tolerance in citrus fruits. The application of pectic oligosaccharides (POs) stimulates the enzymatic antioxidant system in plants and reduces CI development in grapefruit fruit (Citrus paradisi) during cold storage. The aim of this study was to contribute to the basic understanding of peel physiological disorders in cold-stressed ‘Rio Red’ grapefruit fruit at ultrastructural level and to determine whether the POs are involved in the CI reduction by modulating the antioxidant enzymatic system at the transcriptional level. Peel morphology in grapefruit fruit stored at chilling (2 °C) and non-chilling (13 °C) temperatures was analyzed by electronic microscopy and the effect of POs treatment on manganese superoxide dismutase (MnSOD), ascorbate peroxidase (APX1), catalase (CAT1) and glutathione reductase (GR2) gene expression was investigated by RT-qPCR. Results indicate that a prolonged cold storage promoted the incidence of CI symptoms in 'Rio Red' grapefruit and altered the ultrastructural morphology of flavedo epidermal tissue. POs significantly modulated the MnSOD, APX1 and CAT1 expression levels mainly in a storage time- and temperature-dependent manner with regards to controls. By contrast, POs only significantly affected the GR2 gene expression when grapefruit were stored at non-chilling temperatures. Our results revealed a possible involvement of the MnSOD, APX1 and CAT1 genes in the CI susceptibility reduction induced by POs in ‘Rio Red’ grapefruit stored at chilling temperatures.

Melatonin alleviates liver steatosis induced by prenatal dexamethasone exposure and postnatal high-fat diet.

Prenatal exposure to glucocorticoids is associated with negative health consequences for the offspring that persist into adulthood, including liver steatosis. Melatonin has previously been demonstrated to suppress liver steatosis and oxidative stress in humans with non-alcoholic fatty liver disease and in animal models of obesity. The present study aimed to determine whether melatonin protects against liver steatosis induced by prenatal dexamethasone exposure followed by postnatal high-fat diet. Pregnant Sprague-Dawley rats at gestational days 14-21 were administered dexamethasone (0.1 mg/kg/day) or saline via intraperitoneal injection. The offspring were then divided into five groups, as follows: Vehicle, postnatal high-fat diet (VHF), prenatal dexamethasone exposure (DEX), prenatal dexamethasone exposure + postnatal high-fat diet (DHF), and prenatal dexamethasone exposure + postnatal high-fat diet + melatonin (DHFM) group. Following vehicle or dexamethasone exposure of the maternal rats, the offspring rats in the VHF, DHF and DHFM groups received a high-fat diet (58% fat) between weaning and 6 months of age. In the DHFM group, melatonin was administered to the mothers from gestational days 14-21 until weaning. The offspring continued to receive melatonin until they were sacrificed at 6 months old. Oil Red O staining demonstrated stronger intensity in the DHF group compared with that in the other four groups. Western blot analysis also revealed higher levels of cleaved caspase-3, tumor necrosis factor-α (TNF-α), suppressor of cytokine signaling 3 (SOCS3) and malondialdehyde (MDA), as well as reduced expression of manganese superoxide dismutase (MnSOD) and phosphoinositide 3-kinase (PI3K) in the DHF group compared with the vehicle and DHFM groups. In addition, melatonin reduced the Oil Red O staining intensity and the levels of cleaved caspase-3, TNF-α, SOCS3 and MDA, while it increased the MnSOD and PI3K levels, in the DHFM group compared with the DHF group. In conclusion, postnatal high-fat diet aggravated the prenatal dexamethasone-induced liver steatosis in adult rat offspring via inflammation, oxidative stress and cellular apoptosis, which may be ameliorated by prenatal melatonin therapy.

Bush sophora root polysaccharide could help prevent aflatoxin B1-induced hepatotoxicity in the primary chicken hepatocytes

The aim of this study was to evaluate the effects of bush sophora root polysaccharide (BSRPS) on the aflatoxin B1 (AFB1)-induced hepatotoxicity and to explore the underlying mechanisms. The primary chicken hepatocytes were used as the model in the present experiment. The results showed that AFB1 induced hepatotoxicity of chicken hepatocytes in a dose dependent manner as demonstrated by decreasing cell viability and increasing LDH activity, ALT and AST levels. AFB1 at 0.16 μM significantly increased the levels of hepatic cytochrome P450 1A5 (CYP450 1A5) mRNA and malondialdehyde (MDA) and decreased the activity and mRNA level of manganese superoxide dismutase(SOD2) and the glutathione peroxidases (GSH-Px) activity in the hepatocytes compared with the blank control. BSRPS at 8.93 μM, 17.86 μM, and 35.72 μM supplementation could significantly reverse the above-mentioned changes induced by AFB1, and 17.86 μM of BSRPS has the largest effects on protecting the AFB1-induced hepatocytes damage. Knock-down of SOD2 by SOD2-specific siRNA significantly eliminated the protective effects of BSRPS on AFB1-induced the increase of CYP450 1A5 mRNA levels and hepatotoxicity. These results suggested that the BSRPS has protective effects on AFB1-induced hepatotoxicity by down-regulating CYP450 1A5 mRNA level via up-regulating SOD2 expression in the primary chicken hepatocytes.

Effects of flow velocity on growth, metabolism and nitrogen and phosphorus budget of Haliotis discus hannai Ino in a recirculating aquaculture system

To study the effects of different flow velocities on growth, metabolism and nitrogen (N) and phosphorus (P) budget of Haliotis discus hannai Ino in a recirculating aquaculture system, abalones (shell length: 45.71 ± 3.09 mm, body weight: 8.62 ± 0.75 g) were cultured at three different flow velocities with four replicates each: high (400 L/hr), medium (300 L/hr) and low (200 L/hr). At the end of the 70 days experiment, the survival rate, food intake and P utilization rate of abalones in the 200 L/hr group were significantly lower than those in any other group (p < .05), whereas the total ammonia nitrogen and nitrite nitrogen concentrations in the water were significantly higher than those in any other group (p < .05). The body weight specific growth rate, food conversion efficiency, abalone-harvested N and P outputs and N utilization rate were ranked as follows: 300 > 400 > 200 L/hr (p < .05). In the 300 L/hr group, the activities of hexokinase, pyruvate kinase and lactate dehydrogenase were significantly lower than those in the 400 L/hr group, whereas the activity of succinate dehydrogenase was significantly higher than that in the other two groups (p < .05). Aerobic metabolism was the main source of energy acquisition for abalones in the 300 L/hr group. In the 400 L/hr group, the expression levels of manganese superoxide dismutase and thioredoxin peroxidase significantly increased from Day 35 to Day 70, but they still were significantly lower than the values in the 200 L/hr group (p < .05). In the 200 L/hr group, the expression levels of catalase and heat shock protein 70 were significantly higher than those in any other group, and they significantly increased from Day 35 to Day 70 (p < .05). These results indicate that maintaining flow velocity at 300 L/hr will minimize oxidative damage due to deterioration of water quality, reduce the energy consumption required for organisms to resist the impact of water flow, improve the N and P utilization rates of the recirculating aquaculture system, and reduce the cost of culturing abalones.

The association between immunoexpression levels of oxidant and antioxidant enzymes and lip squamous cell carcinoma.

The aim of this study was to investigate the associations among the immunoexpression levels of manganese superoxide dismutase (Mn-SOD), glutathione peroxidase (GPx), and myeloperoxidase (MPO) in lip squamous cell carcinoma (LSCC) tissues and the clinicopathological characteristics, and prognostic factors in patients with LSCC. The immunoexpression levels of Mn-SOD, GPx, and MPO were examined in 76 LSCC tissue samples using immunohistochemical staining on tissue microarray slides, and compared to those in normal lip mucosa adjacent to venous lakes (normal controls), normal tissue adjacent to corresponding tumors (NTACT), and recurrent tumors. Associations between immunoexpression levels and clinicopathological characteristics were analyzed using the Student's t-test. The prognostic factors were analyzed using Cox regression. The immunoexpression levels of Mn-SOD, GPx, and MPO were significantly different among the normal controls, NTACTs, tumors, and recurrent tumors (Mn-SOD: p=0.001, GPx: p<0.001, MPO: p<0.001). Lower lip cancer was associated with higher Mn-SOD immunoexpression levels (p=0.04) and probably indicated higher oxidative stress. Lymph node involvement with a lower immunoexpression level of MPO (p=0.007) indicated compensatory mechanism to attenuate oxidative damage. A low Mn-SOD immunoexpression level was borderline significantly associated with a worse prognosis for disease-specific survival, and it was probably related to a lower capacity for coping with oxidative stress.

Sirtuin 3 silencing improves oxaliplatin efficacy through acetylation of MnSOD in colon cancer.

Sirtuin 3 (SIRT3) is the major mitochondria deacetylase and regulates ROS levels by targeting several key proteins, such as those involved in mitochondrial function and antioxidant defenses. This way, SIRT3 balances ROS production and scavenging and promotes cell survival. The aim of this study was to analyze the effect of SIRT3 silencing on the antioxidant response in SW620 colon cancer cell line, and whether this intervention could improve efficacy of oxaliplatin, a common drug used to treat colon cancer. For this purpose, we obtained stable clones of SW620 with SIRT3 knockdown and determined parameters such as ROS levels and ROS production, levels of several antioxidant enzymes, cell viability, and apoptosis. Results showed that after SIRT3 silencing, both ROS levels and production were increased, and antioxidant enzymes gene expression was significantly reduced. Furthermore, manganese superoxide dismutase levels and enzymatic activity were reduced. Combination of SIRT3 knockdown with oxaliplatin treatment further increased ROS production and apoptosis, reducing cell viability. Finally, survival curves on colon cancer patients suggested that SIRT3 expression is related to a poorer prognosis. In conclusion, SIRT3 could be a target for colon cancer, since it regulates the antioxidant response and its knockdown improves the efficacy of oxaliplatin treatment.

Liraglutide ameliorates early renal injury by the activation of renal FoxO1 in a type 2 diabetic kidney disease rat model

AimsThe aim of this study was to investigate the effects of liraglutide on renal injury and the renal expression of FoxO1 in type 2 diabetic rats. MethodsType 2 diabetic rats model was induced by a high-sugar and high-fat diet and intraperitoneal injection of low-dose Streptozotocin (STZ) (30 mg/kg). Five weeks after STZ injection, diabetic rats were randomly treated with or without subcutaneous injection of liraglutide (0.2 mg/kg/12 h) for eight weeks. Diabetes-related physical and biochemical indicators, renal histopathological and ultrastructural changes, the expression of renal transforming growth factor beta-1 (TGF-β1), fibronectin (FN), type IV collagen (Col IV), protein kinase B (Akt), forkhead box protein O1 (FoxO1) and manganese superoxide dismutase (MnSOD) were measured. ResultsRats in DN group showed a significant increase in fasting blood glucose, HbA1c, kidney to body weight index, serum creatinine (Scr), blood urea nitrogen (BUN), urinary albumin excretion, mesangial matrix index, glomerular basement membrane (GBM) thickening, podocyte foot process fusion, the mRNA and protein levels of renal TGF-β1, FN and Col IV and a dramatic decrease in the mRNA and protein levels of renal MnSOD, all of which were significantly ameliorated by liraglutide. In addition, liraglutide also increased the expression of FoxO1 mRNA and reduced renal phosphorylation levels of Akt and FoxO1 protein. ConclusionsThese results suggest that liraglutide may exert a renoprotective effect by a FoxO1-mediated upregulation of renal MnSOD expression in the early DKD.

Upregulation of FoxM1 by MnSOD Overexpression Contributes to Cancer Stem-Like Cell Characteristics in the Lung Cancer H460 Cell Line.

Manganese superoxide dismutase promotes migration and invasion in lung cancer cells via upregulation of the transcription factor forkhead box M1. Here, we assessed whether upregulation of forkhead box M1 by manganese superoxide dismutase overexpression mediates the acquisition of cancer stem-like cell characteristics in non-small cell lung cancer H460 cells. The second-generation spheroids from H460 cells were used as lung cancer stem-like cells. The levels of manganese superoxide dismutase, forkhead box M1, stemness markers (CD133, CD44, and ALDH1), and transcription factors (Bmi1, Nanog, and Sox2) were analyzed by Western blot. Sphere formation in vitro and carcinogenicity of lung cancer stem-like cells were evaluated by spheroid formation assay and limited dilution xenograft assays. Knockdown or overexpression of manganese superoxide dismutase or/and forkhead box M1 by transduction with short hairpin RNA(shRNA) or complementary DNA were performed for mechanistic studies. We showed that manganese superoxide dismutase and forkhead box M1 amounts as well as the expression levels of stemness markers and transcription factors sphere formation in vitro, and carcinogenicity of lung cancer stem-like cells were higher than in monolayer cells. Lung cancer stem-like cells transduced with manganese superoxide dismutase shRNA or FoxM1 shRNA exhibited decreased sphere formation and lower amounts of stemness markers and transcription factors. Overexpression of manganese superoxide dismutase or FoxM1 in H460 cells resulted in elevated sphere formation rates and protein levels of stemness markers and transcription factors. Meanwhile, manganese superoxide dismutase knockdown or overexpression accordingly altered forkhead box M1 levels. However, forkhead box M1 knockdown or overexpression had no effect on manganese superoxide dismutase levels but inhibited or promoted lung cancer stem-like cell functions. Interestingly, forkhead box M1 overexpression alleviated the inhibitory effects of manganese superoxide dismutase knockdown in lung cancer stem-like cells. In a panel of non-small cell lung cancer cells, including H441, H1299, and H358 cells, compared to the respective monolayer counterparts, the expression levels of manganese superoxide dismutase and forkhead box M1 were elevated in the corresponding spheroids. These findings revealed the role of forkhead box M1 upregulation by manganese superoxide dismutase overexpression in maintaining lung cancer stem-like cell properties. Therefore, inhibition of forkhead box M1 upregulation by manganese superoxide dismutase overexpression may represent an effective therapeutic strategy for non-small cell lung cancer.

Curcumin enhances liver SIRT3 expression in the rat model of cirrhosis.

Objective(s):Bill duct ligation (BDL) is a representative model of biliary cholestasis in animals. Curcumin has a protective effect on the liver; however, its underlying mechanisms are not completely known. This study explored the hepatoprotective activity of curcumin on hepatic damage via measuring the expression of sirtuin3 (SIRT3), AMP-activated protein kinase (AMPK), carnitine palmitoyltransferase 1A (CPT-1A), isocitrate dehydrogenase2 (IDH2) and manganese superoxide dismutase (MnSOD) as well as the level of serum lipid profile in the BDL fibrotic rat model.Materials and Methods:The study consisted of four groups (n=8 for each of Wistar rats): sham group, sham+curcumin (sham+Cur) group (received curcumin 100 mg/kg/day), BDL+Cur group, and BDL group. Transcription levels of SIRT3, AMPK, CPT-1A, IDH2, MnSOD and protein expression level of SIRT3 were measured by real-time PCR and Western blotting, respectively.Results:It was identified that SIRT3, AMPK, CPT-1A, IDH2 and MnSOD expression significantly decreased in BDL rats compared to sham rats; however, in the curcumin treatment of BDL rats, the expression of these factors increased significantly compared to BDL (P<0.05). It was, moreover, observed that treatment of BDL rats with curcumin reduced liver injury as verified by a reduction in the levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) and increase in high-density lipoprotein (HDL) (P <0.05).Conclusion:Curcumin reduced liver damage and oxidative stress in the liver tissue of BDL rats through up-regulation of SIRT3, AMPK, CPT-1A, IDH2 and MnSOD as well as changing the level of serum lipid profile.

In situ different antioxidative systems contribute to the site-specific methylmercury neurotoxicity in mice

Methylmercury (MeHg), an environmental toxicant, induces site-specific neurotoxicity in adult human and animal models. In this study, we demonstrated that MeHg-induced neuropathological changes of the brain in mice were remarkable in the cerebrocortical neurons of deeper layers (dl-CCNs), but not in the CCNs of shallow layers (sl-CCNs) and the hippocampal neurons of cornu ammonis 1 (CA1-HNs). Total mercury concentration was not corresponded to the pathological changes. Here, we investigated the cause of such site-specific MeHg neurotoxicity with a focus on in situ antioxidative systems due to its critical role in MeHg intoxication. We performed in situ analyses of antioxidative enzymes expression using RT-qPCR analyses from laser microdissected sl-CCNs, dl-CCNs, and CA1-HNs samples, and immunohistochemistry. The results of antioxidative enzymes expression analyses demonstrated the lowest basal expression levels of mRNA and proteins, especially manganese superoxide dismutase (Mn-SOD) and glutathione peroxidase 1 (GPx1) in dl-CCNs. In addition, the Mn-SOD expression showed a lowest response to MeHg in dl-CCNs. We also performed enzymatic activity analyses for antioxidative enzymes using separated cerebral cortex and hippocampus. The results of enzymatic activity analyses indicate that the expression levels of antioxidative enzymes reflect their enzymatic activities. Immunostaining of thymidine glycerol, a sensitive oxidative stress marker, showed selectively increased expression in dl-CCNs after the exposure to MeHg but not in sl-CCNs and CA1-HNs, suggesting the occurrence of MeHg-induced oxidative stress in dl-CCNs. The differences in MeHg-induced occurrence of oxidative stress and pathological changes in sl-CCNs, dl-CCNs, and CA1-HNs corresponded to the basal level of Mn-SOD and GPx1 expression and the different protective response of Mn-SOD expression to MeHg. These findings suggest that the in situ different antioxidative systems play a role in the site-specific neurotoxicity of MeHg.

Light cycle effects on Haliotis discus hannai Ino growth, energy budget, and related gene expression

This study investigated the effects of different light cycles on growth, food intake, energy budget, and related gene expression of the abalone Haliotis discus hannai Ino. Abalones (mean±standard error shell length: 30.28±1.64mm, body weight: 4.51±0.49g) were exposed to the following light cycles: 0L:24D, 4L:20D, 8L:16D, 12L:12D, and 16L:8D for 60days, four repetitions were provided for each light cycle. At the end of the experiment, there was no significant difference in shell length or body weight growth rate between 0L:24D and 4L:20D (P>0.05), the values of which were significantly higher than in 16L:8D (P<0.05). In 0L:24D, abalone food intake was significantly higher compared with in the other groups (P<0.05), but the food conversion efficiency was significantly lower than in 4L:20D (P<0.05). At the end of the experiment, in 16L:8D, the activity of hexokinase was significantly higher than in any other group (P<0.05), but in 12L:12D and 16L:8D, it significantly increased compared with Day 30 (P<0.05). In 0L:24D, 4L:20D, and 8L:16D, cellulase and pyruvate kinase activity was significantly higher than in 12L:12D and 16L:8D (P<0.05). There was no significant difference in the energy acquired from food in 0L:24D and 4L:20D (P>0.05). However, the energy loss via feces and respiratory metabolism in 0L:24D was significantly higher than in 4L:20D (P<0.05); therefore, the energy accumulated for individual growth was significantly lower than in 4L:20D (P<0.05). Although the energy loss via feces, excretion, and respiratory metabolism was significantly lower in 16L:8D compared with 0L:24D, 4L:20D, and 8L:16D, the ratio of the energy loss via feces and respiratory metabolism to the energy acquired from food intake was significantly higher than in any other group (P<0.05); therefore, the net growth efficiency K2 was significantly lower (P<0.05). In 16L:8D, gene expression levels of manganese superoxide dismutase (Mn-SOD), catalase (CAT), TPx, heat shock protein (HSP) 26, HSP70, and HSP90 were significantly higher than in any other group (P<0.05). At the end of the experiment, Mn-SOD, CAT, and HSP70 expression in 16L:8D significantly increased compared with Day 30 (P<0.05). Therefore, considering aquaculture production and business costs, it would be appropriate to select the light cycle of 4L:20D for the culture of H. d. hannai.

Changes in mitochondrial properties may contribute to enhanced resistance to ischemia-reperfusion injury in the diabetic rat heart.

Diabetes mellitus, besides having deleterious effects, induces cardiac adaptation that may reduce the heart's susceptibility to ischemia-reperfusion (IR) injury. This study aimed to investigate whether changes in mitochondrial properties are involved in the mechanisms of increased resistance of the diabetic heart to IR. Adult male Wistar rats were made diabetic by a single dose of streptozotocin (65 mg·kg-1, i.p.), and on the day 8, Langendorff-perfused hearts were subjected to 30 min global ischemia and 40 min reperfusion. Baseline preischemic parameters in the diabetic hearts did not differ markedly from those in the nondiabetic controls, except for lower left ventricular developed pressure, higher mitochondrial membrane fluidity, and protein levels of manganese superoxide dismutase. On the other hand, diabetic hearts showed significantly better post-IR functional restoration and reduced arrhythmogenesis associated with lower reactive oxygen species production as compared with healthy controls. IR decreased membrane fluidity in both experimental groups; however, it led to a complete recovery of mitochondrial Mg2+-ATPase activity in diabetics in contrast to its reduction in nondiabetics. These findings indicate that the heart may become adapted to diabetes-induced alterations that might increase its tolerance to an ischemic insult. Preserved mitochondrial function might play a role in the mechanisms of the heart's resistance to IR injury in diabetics.

MP12-19 CALCIUM OXALATE CRYSTALS INDUCE MITOCHONDRIAL DYSFUNCTION AND HEME OXYGENASE-1 EXPRESSION IN A HUMAN MONOCYTE DERIVED CELL LINE

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology I1 Apr 2017MP12-19 CALCIUM OXALATE CRYSTALS INDUCE MITOCHONDRIAL DYSFUNCTION AND HEME OXYGENASE-1 EXPRESSION IN A HUMAN MONOCYTE DERIVED CELL LINE Vidhush K Yarlagadda, Dean G Assimos, Ross P Holmes, and Tanecia R Mitchell Vidhush K YarlagaddaVidhush K Yarlagadda More articles by this author , Dean G AssimosDean G Assimos More articles by this author , Ross P HolmesRoss P Holmes More articles by this author , and Tanecia R MitchellTanecia R Mitchell More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.441AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Monocytes and macrophages are essential for renal crystal clearance and are recruited into the renal interstitium during this process. Mitochondria are critical for monocyte function during the immune response and oxidative stress cell signaling. Heme oxygenase-1 (HO-1) and manganese superoxide dismutase (MnSOD) are inducible stress response proteins that have been shown to be involved in mitochondrial and anti-inflammatory signaling. We recently demonstrated that monocyte mitochondrial function is decreased in calcium oxalate (CaOx) stone formers when compared to healthy subjects. The objective of this study was to determine whether CaOx crystals alter mitochondrial function, cell viability, and expression of HO-1 and MnSOD in THP-1 cells, a human monocyte derived cell line. METHODS To test this hypothesis, THP-1 cells were treated with CaOx crystals (0 μg, 50 μg, 100 μg, 200 μg, 500 μg, 1000 μg) for 24 hours prior to measuring mitochondrial function (Seahorse XF96 technology), cell viability (Trypan Blue), and HO-1 and MnSOD expression (Western Blotting). These experiments were repeated in triplicate. RESULTS Exposing CaOx crystals to THP-1 cells caused a dose dependent decrease in mitochondrial function and cell viability (p < 0.05). Both HO-1 and MnSOD protein levels were significantly increased in a dose dependent fashion with CaOx crystal treatment (p < 0.05). Furthermore, HO-1 levels were upregulated to a greater extent than MnSOD levels with increased crystal exposure. CONCLUSIONS In summary, CaOx crystals appear to decrease mitochondrial function and cell viability and induce stress response proteins in THP-1 monocytes. These findings provide potential mechanisms responsible for mitochondrial dysfunction observed in monocytes from CaOx stone formers. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e151-e152 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Vidhush K Yarlagadda More articles by this author Dean G Assimos More articles by this author Ross P Holmes More articles by this author Tanecia R Mitchell More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Effects of 17β-estradiol and 2-methoxyestradiol on the oxidative stress-hypoxia inducible factor-1 pathway in hypoxic pulmonary hypertensive rats.

The present study aimed to investigate the effects of 17β-estradiol (E2) and 2-methoxyestradiol (2ME) on the oxidative stress-hypoxia inducible factor-1 (OS-HIF-1) pathway in hypoxic pulmonary hypertensive rats. Female Sprague-Dawley rats were divided randomly into 4 groups, as follows: i) Control (Group A); ii) ovariectomy (OVX) + hypoxia (Group B); iii) OVX + hypoxia + E2 injection (Group C); and iv) 2ME injection (Group D). The rats were maintained under hypoxic conditions for 8 weeks, and mean pulmonary artery pressure (mPAP) and pulmonary arteriole morphology were measured. The reactive oxygen species, superoxide dismutase (SOD), manganese superoxide dismutase (MnSOD), and copper-zinc superoxide dismutase (Cu/ZnSOD) levels in serum were also measured. MnSOD and HIF-1α expression levels in lung tissue were determined by western blotting and reverse transcription-quantitative polymerase chain reaction. The mPAP and arterial remodeling index were significantly elevated following chronic hypoxia exposure; however, experimental data revealed a reduced response in E2 and 2ME intervention rats. Compared with Group A, Group B had significantly elevated oxidative stress levels, as illustrated by increased serum ROS levels, decreased serum SOD and MnSOD levels and decreased MnSOD mRNA and protein expression levels in lung tissue. Furthermore, HIF-1α mRNA and protein expression in Group B was significantly elevated compared with Group A. E2 and 2ME intervention significantly attenuated the aforementioned parameter changes, suggesting that E2 and 2ME partially ameliorate hypoxic pulmonary hypertension. The underlying mechanism of this may be associated with the increase in MnSOD activity and expression and reduction in ROS level, which reduces the levels of transcription and translation of HIF-1α.

Impaired Mitochondrial Respiration in Large Cerebral Arteries of Rats with Type 2 Diabetes

Mitochondrial dysfunction has been suggested as a potential underlying cause of pathological conditions associated with type 2 diabetes (T2DM). We have previously shown that mitochondrial respiration and mitochondrial protein levels were similar in the large cerebral arteries of insulin-resistant Zucker obese rats and their lean controls. In this study, we extend our investigations into the mitochondrial dynamics of the cerebral vasculature of 14-week-old Zucker diabetic fatty obese (ZDFO) rats with early T2DM. Body weight and blood glucose levels were significantly higher in the ZDFO group, and basal mitochondrial respiration and proton leak were significantly decreased in the large cerebral arteries of the ZDFO rats compared with the lean controls (ZDFL). The expression of the mitochondrial proteins total manganese superoxide dismutase (MnSOD) and voltage-dependent anion channel (VDAC) were significantly lower in the cerebral microvessels, and acetylated MnSOD levels were significantly reduced in the large arteries of the ZDFO group. Additionally, superoxide production was significantly increased in the microvessels of the ZDFO group. Despite evidence of increased oxidative stress in ZDFO, exogenous SOD was not able to restore mitochondrial respiration in the ZDFO rats. Our results show, for the first time, that mitochondrial respiration and protein levels are compromised during the early stages of T2DM.

(−)-Epigallocatechin-3-gallate alleviates doxorubicin-induced cardiotoxicity in sarcoma 180 tumor-bearing mice

Aims(−)-Epigallocatechin-3-gallate (EGCG), a major green tea polyphenol compound, plays an important role in the prevention of cardiovascular disease and cancer. The present study aimed to investigate the effects of EGCG on doxorubicin (DOX)-induced cardiotoxicity in Sarcoma 180 (S180) tumor-bearing mice. Main methodsS180 tumor-bearing mice were established by subcutaneous inoculation of S180 cells attached to the axillary region. The extent of myocardial injury was accessed by the amount of lactate dehydrogenase (LDH) released in serum. Heart tissue was morphologically studied with transmission electron microscopy. Apoptosis, reactive oxygen species (ROS) generation, mitochondrial membrane potential (ΔѰm) as well as calcium concentration were measured by flow cytometric analysis. Expression levels of manganese superoxide dismutase (MnSOD) were analyzed by Western blot. Key findingsResults showed that the combination with EGCG and DOX significantly inhibited tumor growth and enhanced induction of apoptosis compared with DOX alone. Moreover, administration of EGCG could suppress DOX-induced cardiotoxicity as evidenced by alleviating LDH release and apoptosis in cardiomyocyte. EGCG-evoked cardioprotection was in association with the increase of ΔѰm and MnSOD expression. EGCG was also found to attenuate ROS generation and myocardial calcium overload in Sarcoma 180 tumor-bearing mice subjected to DOX. SignificanceEGCG alleviated DOX-induced cardiotoxicity possibly in part mediated by increasing of MnSOD and Ѱm, reducing myocardial calcium overload and subsequently attenuating the apoptosis and LDH release. Our findings suggest that co-administration of EGCG and DOX have potential as a feasible strategy to mitigate cardiotoxicity of DOX without compromising its chemotherapeutic value.

Glucagon-Like Peptide-1 Analog, Liraglutide, Delays Onset of Experimental Autoimmune Encephalitis in Lewis Rats.

Introduction: Recent findings indicate that metabolic disturbances are involved in multiple sclerosis (MS) pathology and influence the susceptibility to treatment, directing attention toward anti-diabetic drugs such as metformin and pioglitazone. Liraglutide, a drug of the glucagon-like peptide-1 (GLP-1) family, is also anti-diabetic and weight-reducing and is, moreover, directly neuroprotective and anti-inflammatory in a broad spectrum of experimental models of brain disease. In this study we investigate the potential for this FDA-approved drug, liraglutide, as a treatment for MS by utilizing the experimental model, experimental autoimmune encephalitis (EAE).Methods: EAE was induced in 30 female Lewis rats that subsequently received twice-daily liraglutide (200 μg/kg s.c.) or saline. Healthy controls were included (saline, n = 6, liraglutide, n = 7). Clinical score and weight were assessed daily by blinded observers. Animals were killed at peak disease severity (day 11) or if exceeding humane endpoint (clinical score ≥4). Protein levels of manganese superoxide dismutase (MnSOD), amyloid precursor protein (APP), and glial fibrillary acidic protein (GFAP) were determined.Results: Liraglutide treatment delayed disease onset (group clinical score significantly >0) by 2 days and markedly reduced disease severity (median clinical score 2 vs. 5; p = 0.0003). Fourteen of 15 (93%) of vehicle-treated rats reached the humane endpoint (clinical score ≥4) by day 11 compared to 5 of 15 (33%) of liraglutide-treated rats (p = 0.0004). Liraglutide substantially increased the mitochondrial antioxidant MnSOD (p < 0.01) and reduced the neurodegenerative marker APP (p = 0.036) in the brain. GFAP levels were not significantly changed with drug treatment (p = 0.09).Conclusion: We demonstrate, for the first time, that liraglutide treatment delays onset of EAE in Lewis rats and is associated with improved protective capacity against oxidative stress. These data suggest GLP-1 receptor agonists should be investigated further as a potential therapy for MS.

Targeting the superoxide/nitric oxide ratio by L-arginine and SOD mimic in diabetic rat skin

Setting the correct ratio of superoxide anion (O2•-) and nitric oxide (•NO) radicals seems to be crucial in restoring disrupted redox signaling in diabetic skin and improvement of •NO physiological action for prevention and treatment of skin injuries in diabetes. In this study we examined the effects of L-arginine and manganese(II)-pentaazamacrocyclic superoxide dismutase (SOD) mimic – M40403 in diabetic rat skin. Following induction of diabetes by alloxan (blood glucose level ≥12 mMol l −1) non-diabetic and diabetic male Mill Hill hybrid hooded rats were divided into three subgroups: (i) control, and receiving: (ii) L-arginine, (iii) M40403. Treatment of diabetic animals started after diabetes induction and lasted for 7 days. Compared to control, lower cutaneous immuno-expression of endothelial NO synthase (eNOS), heme oxygenase 1 (HO1), manganese SOD (MnSOD) and glutathione peroxidase (GSH-Px), in parallel with increased NFE2-related factor 2 (Nrf2) and nitrotyrosine levels characterized diabetic skin. L-arginine and M40403 treatments normalized alloxan-induced increase in nitrotyrosine. This was accompanied by the improvement/restitution of eNOS and HO1 or MnSOD and GSH-Px protein expression levels in diabetic skin following L-arginine, i.e. SOD mimic treatments, respectively. The results indicate that L-arginine and M40403 stabilize redox balance in diabetic skin and suggest the underlying molecular mechanisms. Restitution of skin redox balance by L-arginine and M40403 may represent an effective strategy to ameliorate therapy of diabetic skin.