Manganese Superoxide Dismutase mRNA Research Articles

Silver nanoparticle-induced cell damage via impaired mtROS-JNK/MnSOD signaling pathway

This study investigated the mechanism of silver nanoparticle (AgNP) cytotoxicity from a mitochondrial perspective. The effect of AgNP on manganese superoxide dismutase (MnSOD), a mitochondrial antioxidant enzyme, against oxidative stress has not been studied in detail. We demonstrated that AgNP decreased MnSOD mRNA level, protein expression, and activity in human Chang liver cells in a time-dependent manner. AgNP induced the production of mitochondrial reactive oxygen species (mtROS), particularly superoxide anion. AgNP was found to increase mitochondrial calcium level and disrupt mitochondrial function, leading to reduced ATP level, succinate dehydrogenase activity, and mitochondrial permeability. AgNP induced cytochrome c release from the mitochondria into the cytoplasm, attenuated the expression of the anti-apoptotic proteins phospho Bcl-2 and Mcl-1, and induced the expression of the pro-apoptotic proteins Bim and Bax. In addition, c-Jun N-terminal kinase (JNK) phosphorylation was significantly increased by AgNP. Treatment with elamipretide (a mitochondria-targeted antioxidant) and SP600125 (a JNK inhibitor) showed the involvement of MnSOD and JNK in these processes. These results indicated that AgNP damaged human Chang liver cells by destroying mitochondrial function through the accumulation of mtROS.

Multicolor-Encoded DNA Framework Enables Specific and Amplified In Situ Detection of the Mitochondrial Apoptotic Signaling Pathway.

Monitoring the molecular activation networks of cellular processes through fluorescence imaging to accurately elucidate the signaling pathways of mitochondrial apoptosis and the regulation of upstream and downstream molecules remains a current major challenge. In this work, a multicolor-encoded tetrahedral DNA framework (meTDF) carrying two pairs of catalytic hairpins is synthesized to monitor the intracellular upstream manganese superoxide dismutase (MnSOD) mRNA and the downstream cytochrome c (Cyt c) molecules for specific and sensitive detection of the mitochondrial apoptotic signaling pathway. These two types of molecules can trigger catalytic hairpin assembly (CHA) reactions with accelerated reaction kinetics for the hairpin pairs confined on meTDF to show highly amplified fluorescence for sensitive and simultaneous detection of MnSOD mRNA and Cyt c with detection limits of 3.7 pM and 0.23 nM in vitro, respectively. Moreover, the high stability and biocompatibility of the designed meTDF can facilitate efficient delivery of the probes into cells to monitor intracellular MnSOD mRNA and Cyt c for specific detection of the mitochondrial apoptosis pathway regulated by different drugs. With the successful demonstration of their robust capability, the meTDF nanoprobes can thus open new opportunities for detecting cell apoptotic mechanisms for studying the corresponding apoptotic signaling pathways and for screening potential therapeutic drugs.

Mass Nanotags Mediate Parallel Amplifications on Nanointerfaces for Multiplexed Profiling of RNAs.

Multiplexed profiling of RNAs aids in a comprehensive understanding of multiparameter-defined cellular processes and pathological states. We herein present a mass nanotags-enabled interfacial assembly system (MNTs-AS) with parallel amplification motors for simultaneous assaying of multiple RNAs in biosystems by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Four kinds of MNTs encoding corresponding RNA can be cyclically assembled on magnetic beads by target-triggered catalytic hairpin assembly (CHA) machineries on nanointerfaces, generating multiplexed and amplified characteristic ion signals assigned to target RNAs upon MALDI MS interrogation. By virtue of high sensitivity and multiplexing capability, the MNTs-AS-based MS assay allows precision subtyping of diverse breast cancer cells and their exosomes by multiplexed profiling of miRNA-21, miRNA-373, miRNA-155, and manganese superoxide dismutase mRNA via a single MS inquiry. This method provides a promising tool for unraveling multiple RNA-involved biological events in fundamental research and distinguishing different cancer subtypes in clinical practice.

Effects of bamboo leaf extract on energy metabolism, antioxidant capacity, and biogenesis of small intestine mitochondria in broilers.

The present study was carried out to investigate the effects of bamboo leaf extract (BLE) on energy metabolism, antioxidant capacity, and biogenesis of broilers' small intestine mitochondria. A total of 384 one-day-old male Arbor Acres broiler chicks were randomly divided into four groups with six replicates each for 42 d. The control group was fed a basal diet, whereas the BLE1, BLE2, and BLE3 groups consumed basal diets with 1.0, 2.0, and 4.0 g/kg of BLE, respectively. Some markers of mitochondrial energy metabolism including isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase and some markers of redox system including total superoxide dismutase, malondialdehyde, and glutathione were measured by commercial colorimetric kits. Mitochondrial and cellular antioxidant genes, mitochondrial biogenesis-related genes, and mitochondrial DNA copy number were measured by quantitative real-time-polymerase chain reaction (qRT-PCR). Data were analyzed using the SPSS 19.0, and differences were considered as significant at P < 0.05. BLE supplementation linearly increased jejunal mitochondrial isocitrate dehydrogenase (P < 0.05) and total superoxide dismutase (P < 0.05) activity. The ileal manganese superoxide dismutase mRNA expression was linearly affected by increased dietary BLE supplementation (P < 0.05). Increasing BLE supplementation linearly increased jejunal sirtuin 1 (P < 0.05) and nuclear respiratory factor 1 (P < 0.05) mRNA expression. Linear (P < 0.05) and quadratic (P < 0.05) responses of the ileal nuclear respiratory factor 2 mRNA expression occurred with increased dietary BLE levels. In conclusion, BLE supplementation was beneficial to the energy metabolism, antioxidant capacity, and biogenesis of small intestine mitochondria in broilers. The dose of 4.0 g/kg BLE demonstrated the best effects.

Electroacupuncture preconditioning alleviates renal injury and oxidative stress through Sirt3/MnSOD pathway in type 2 diabetic rats

To explore the protective effect and molecular mechanism of electroacupuncture (EA) preconditioning on renal injury in type 2 diabetic rats. Fifty male Wistar rats were randomly divided into control, model, EA, EA+inhibitor, and inhibitor groups, with 10 rats in each group. Diabetes model was established by high fat and high glucose diet and intraperitoneal injection of streptozotocin (40 mg/kg). EA (2 Hz, 1 mA) preconditioning was applied to "Guanyuan" (CV4), "Zhongwan" (CV12), bilateral "Zusanli" (ST36) and "Fenglong" (ST40) for 15 min, once every other day for 8 weeks. Rats of the inhibitor and EA+inhibitor groups were given intraperitoneal injection of 3-TYP (50 mg/kg) once every other day for a total of 3 times. The body weight, kidney mass, and renal index were recorded. The contents of urine microalbumin (ALB), 24 h urine 8-hydroxydeoxyguanosine (8-OHdG) and activities of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione glycine peroxidase (GSH-Px) in kidney were detected by ELISA. The activities of mitochondrial respiratory chain enzyme complex (RCCⅠ-RCCⅣ) in kidney were detected using spectrophotometric method. HE staining, Masson staining and transmission electron microscopy were used to observe the changes of renal structure. The protein and mRNA expressions of silent information regulator 3 (Sirt3), manganese superoxide dismutase (MnSOD) in kidney were detected by Western blot and quantitative real-time PCR, respectively. After modeling and compared with the control group, the contents of ALB, the renal index, activity of ROS and content of 8-OHdG, and the renal collagen volume fraction (CVF) were increased (P<0.01), while the activities of SOD, CAT and GSH-Px, RCCⅠ-RCCⅣ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.01). After the treatment and compared with the model group, the contents of ALB, the renal index, ROS, 8-OHdG, and the CVF were decreased in the EA group(P<0.01, P<0.05), while the activities of SOD, CAT, GSH-Px, RCCⅠ-RCCⅣ, and Sirt3 and MnSOD expression levels were increased (P<0.01, P<0.05)；the RCCⅡ activity and the expression level of MnSOD mRNA were increased (P<0.05) in the EA+inhibitor group; the ALB and 8-OHdG contents and the CVF in the inhibitor group were increased (P<0.05), while the activity of SOD, and Sirt3 and MnSOD expression levels were decreased (P<0.05). In comparison with the EA group, the contents of ALB, the renal index, activities of ROS and 8-OHdG contents, and the CVF were increased (P<0.05, P<0.01), activities of SOD, CAT and GSH-Px and RCCⅠ and RCCⅡ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.05, P<0.01) in both EA+inhibitor group and inhibitor group, whereas the activities of RCCⅢ and RCCⅣ were decreased in the inhibitor group (P<0.05). The therapeutic effect of inhibitor was notably inferior to that of EA+inhibitor in decreasing ALB and 8-OHdG contents, and CVF (P<0.01), and in up-regulating SOD and RCCⅡ activities, Sirt3 and MnSOD expression levels (P<0.01, P<0.05). EA preconditioning can increase the expressions of renal Sirt3 and MnSOD in type 2 diabetic rats, thereby reducing the oxidative stress response and protecting the kidneys.

PKCε Activation Restores Loss of PKCε, Manganese Superoxide Dismutase, Vascular Endothelial Growth Factor, and Microvessels in Aged and Alzheimer's Disease Hippocampus.

Vascular endothelial dysfunction and capillary loss are currently considered to be a primary phenotype of normal human aging and Alzheimer’s disease (AD). Activation of protein kinase C (PKCε) improves several molecular, cellular, physiological, and behavioral endpoints, yet it is not known whether a loss of PKCε activity occurs in the microvascular endothelium in aged and AD hippocampi, whether this loss contributes to microvascular change, or whether activation of PKCε protects against microvascular damage, an early change that induces age-associated memory defect and AD. We investigated the effect of the PKCε activation on microvascular loss in the hippocampus, important for memory storage. In cultured human brain microvascular endothelial cells, tert-butyl hydroperoxide induced oxidative stress and a decrease in manganese superoxide dismutase (MnSOD) mRNA and protein expression that were blocked by the antioxidant drugs. The PKCε activators bryostatin and DCPLA methyl ester increased PKCε, associated with an increase in MnSOD mRNA and its protein as well as vascular endothelial growth factor (VEGF), which was inhibited by the mRNA-stabilizing HuR inhibitors. In rats (>24 months old) and AD transgenic mice Tg2576 (5 months old), bryostatin or DCP-LA prevented a decrease in vascular PKCε, MnSOD, and VEGF and prevented microvascular loss and age-related memory impairment. An autopsy-confirmed AD hippocampus showed a decrease in PKCε and MnSOD mRNAs and their proteins and VEGF as well as in microvascular density compared to non-AD controls. In conclusion, the PKCε activation can rescue a decrease in PKCε, MnSOD, and VEGF via posttranscription regulation and alleviate oxidative stress, and in doing so, prevent microvascular loss during aging and AD.

The role of dietary chromium supplementation in relieving heat stress of juvenile blunt snout bream Megalobrama amblycephala

The present study assessed the role of dietary chromium (Cr) supplementation in relieving heat stress (HS) of juvenile blunt snout bream Megalobrama amblycephala. The supplemented Cr contents by chromium picolinate (Cr-Pic) was 0 mg/kg (control group), 0.4 mg/kg, 1.6 mg/kg and 12.0 mg/kg, respectively. The fish continued to be fed four diets at suitable temperatures (26 °C) for 2 weeks, and then the temperature was then heated up to 33 °C through thermo-regulated system. The results showed that Cr supplementation had no significant effect on the immune indices and antioxidant indices before HS (P > 0.05). However, Cr supplementation played an important role in relieving HS. After HS, compared with the control group, 1.6 mg/kg and 12.0 mg/kg Cr supplementation groups significantly lowered the plasma glucose level and aspartate transaminase (AST) activity (P < 0.05), and 0.4 mg/kg and 1.6 mg/kg Cr supplementation groups significantly lowered alanine aminotransferase (ALT) activity (P < 0.05). 0.4 mg/kg and 1.6 mg/kg supplementation groups significantly improved hepatic total superoxide dismutase (T-SOD) activity (P < 0.05). Furthermore, 0.4mg/kg-12.0 mg/kg Cr supplementation groups significantly improved the activities of hepatic glutathione peroxidase (GPx) and catalase (CAT) and lowered hepatic malondialdehyde (MDA) level in liver (P < 0.05). The mRNA levels of hepatic copper zinc superoxide dismutase (Cu/Zn-SOD), CAT and GPx were significantly improved in 0.4mg/kg-12.0 mg/kg supplementation Cr groups (P < 0.05), however, there was no significant variation of hepatic manganese superoxide dismutase (Mn-SOD) mRNA levels under different levels of supplementation (P > 0.05). Significantly lower mRNA levels of hepatic pro-inflammatory cytokines observed in 0.4mg/kg-12.0 mg/kg Cr supplementation groups including tumour necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and interleukin 8 (IL-8) (P < 0.05), and 0.4mg/kg-12.0 mg/kg Cr supplementation significantly improved the relative expressions of hepatic heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90) (P < 0.05). The present study indicated that dietary Cr supplementation might have no significant effect on immune capacity and antioxidant capacity under normal physiological conditions, whereas it played an important role in relieving HS.

Estrogen Replacement Therapy Induces Antioxidant and Longevity-Related Genes in Women after Medically Induced Menopause.

Females live longer than males in many species, including humans, and estrogens are in part responsible for this protection against aging. We reported previously that estrogens can protect rats against oxidative stress, by inducing antioxidant and longevity-related genes. Thus, this study was aimed at confirming the ability of estrogens to upregulate antioxidant and longevity-related genes in humans. For this purpose, we selected 16 women of reproductive age (18-42 years old) undergoing a fertility treatment that includes a medically induced menopause, at the Valencian Infertility Institute. We took blood samples at each time point of the treatment (basal, induced menopause, estrogen, and estrogen plus progesterone replacement therapy). mRNA expression of antioxidant and longevity-related genes in peripheral blood mononuclear cells (PBMC) was determined by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Determination of reduced glutathione (GSH) in total blood was carried out using high-performance liquid chromatography (HPLC). As expected, we found that medically induced menopause significantly decreased sexual hormone (estrogens and progesterone) levels. It also lowered glutathione peroxidase (GPx), 16S rRNA, P21, and TERF2 mRNA expression and blood GSH levels. Estrogen replacement therapy significantly restored estrogen levels and induced mRNA expression of manganese superoxide dismutase (MnSOD), GPx, 16S rRNA, P53, P21, and TERF2 and restored blood GSH levels. Progesterone replacement therapy induced a significant increase in MnSOD, P53, sestrin 2 (SENS2), and TERF2 mRNA expression when compared to basal conditions. These findings provide evidence for estrogen beneficial effects in upregulating antioxidant and longevity-related genes in women.

Cloning of Mn-SOD gene and its mRNA expression difference and antioxidant enzyme activities under hypoxia stress of cobia Rachycentron canadum.

Environmental hypoxia affects the survival and development of organisms. It is also an important environmental factor that leads to oxidative damage. Hypoxia is a condition in which tissues are deprived of oxygen; reoxygenation is the phenomenon in which hypoxic tissues are exposed to oxygen. Hypoxia-reoxygenation is vital in pathogenesis, where the production of reactive oxygen species and antioxidant disparity significantly contribute to disease progression, and it is one of the most common physiological stressors in the aquaculture industry. In this study, the full length of complementary DNA (cDNA) of the manganese superoxide dismutase (Mn-SOD) gene of healthy cobia Rachycentron canadum was analysed using rapid amplification of cDNA ends. The real-time quantitative Polymerase Chain Reaction was used to measure the expression levels of Mn-SOD mRNAs in various tissues (heart, muscle, brain, liver, kidney, gill, intestine, and spleen). The 2-ΔΔCT method was used to performed the expression analysis. The experimental data were analysed using SPSS ver. 19.0 ( https://spss.software.informer.com/19.0/ ). P < 0.05 and P < 0.01 were set as significant differences. The values were articulated as mean ± standard deviation. The Mn-SOD gene cDNA sequence was 1209bp long, including a 684bp open reading frame, 42bp 5'UTR and 483bp 3'UTR, encoding 227 amino acids. Under hypoxia-reoxygen stress, the expression of Mn-SOD in brain tissue was significantly lower than in the control group after 8h of reoxygenation and higher than the control group after 24h. Hypoxia and subsequent reoxygenation triggered a disturbance in antioxidant homeostasis, displayed in the modification of GPx expression/activity in the liver: GPx was improved. These results provide valuable information on the role of Mn-SOD regulation in oxidative stress caused by hypoxia.

Sirtuin 3 Inhibits Airway Epithelial Mitochondrial Oxidative Stress in Cigarette Smoke-Induced COPD.

Mitochondrial damage in airway epithelial cells plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Sirtuin 3 (Sirt3) is a mitochondrial deacetylase regulating mitochondrial function, but its role in the pathogenesis of COPD is still unknown. The aim of the present study was to investigate the effect of Sirt3 on airway epithelial mitochondria in cigarette smoke-induced COPD. Our present study has shown serious airway inflammation, alveolar space enlargement, and mitochondrial damage of the airway epithelium in COPD rats. Compared to the control rats, Sirt3 protein expression was significantly decreased in the airway epithelium and lung tissue homogenate from COPD rats. In airway epithelial cells (BEAS-2B), cigarette smoke extract (CSE) treatment significantly decreased mRNA and protein expression of Sirt3 and manganese superoxide dismutase (MnSOD), as well as MnSOD activity in a concentration and time-dependent manner. Sirt3 siRNA further significantly intensified the decreases in MnSOD expression and activity and aggravated mitochondrial oxidative stress and cell injury when airway epithelial cells were treated with 7.5% CSE. In contrast, Sirt3 overexpression significantly prevented the decrease of MnSOD expression and activity and improved mitochondrial oxidative stress and cell injury in CSE-treated airway epithelial cells. These data suggest that Sirt3 inhibits airway epithelial mitochondrial oxidative stress possibly through the regulation of MnSOD, thereby contributing to the pathogenesis of COPD.

Exendin-4 Attenuates Remodeling in the Remote Myocardium of Rats After an Acute Myocardial Infarction by Activating β-Arrestin-2, Protein Phosphatase 2A, and Glycogen Synthase Kinase-3 and Inhibiting β-Catenin.

This study tested if the protective anti-remodeling effect of GLP-1 agonist Exendin-4 after an acute myocardial infarction (MI) in rats involves inhibition of the Wnt1/β-catenin signaling pathway. Rats were divided into sham, sham + Exendin-4 (10μg/day, i.p), MI, and MI + Exendin-4. MI was introduced to rats by permanent left anterior descending coronary artery (LAD) ligation. On day 7 post-infraction, MI rats showed LV dysfunction with higher serum levels of cardiac markers. Their remote myocardia showed increased mRNA and protein levels of collagen I/III with higher levels of reactive oxygen species (ROS) and inflammatory cytokines, as well as protein levels of Wnt1, phospho-Akt, transforming growth factor (TGF-β1), Smad, phospho-Smad3, α-SMA, caspase-3, and Bax. They also showed higher protein levels of phospho-glycogen synthase kinase-3β (p-GSK3β), as well as total, phosphorylated, and nuclear β-catenin with a concomitant decrease in the levels of cyclic adenosine monophosphate (cAMP), mRNA of manganese superoxide dismutase (MnSOD), and protein levels of Bcl-2, β-arrestin-2, and protein phosphatase-2 (PP2A). Administration of Exendin-4 to MI rats reduced the infarct size and reversed the aforementioned signaling molecules without altering protein levels of TGF-1β and Wnt1 or Akt activation. Interestingly, Exendin-4 increased mRNA levels of MnSOD, protein levels of β-arrestin-2 and PP2A, and β-catenin phosphorylation but reduced the phosphorylation of GSK3β and Smad3, and total β-catenin levels in the LV of control rats. Exendin-4 inhibits the remodeling in the remote myocardium of rats following acute MI by attenuating β-catenin activation and activating β-arrestin-2, PP2A, and GSK3β. Graphical Abstract A graphical abstract that illustrates the mechanisms by which Exendin-4 inhibits cardiac remodeling in remote myocardium of left ventricle MI-induced rats. Mechanisms are assumed to occur in the cardiomyocytes and/or other resident cells such as fibroblast. Β-catenin activation and nuclear translocation are associated with increased synthesis of inflammatory cytokines and transforming growth factor β-1 (TGF-β1). GSK3β is inhibited by phosphorylation at Ser9. Under normal conditions, β-catenin is degraded in the cytoplasm by the active GSK3β-dependent degradation complex (un-phosphorylated) which usually phosphorylates β-catenin at Ser33/37/Thr41. After MI, TGF-β1, and Wnt 1 levels are significantly increased, the overproduction of Wnt1 induces β-catenin stabilization and nuclear translocation through increasing the phosphorylation of disheveled (DVL) protein which in turn phosphorylates and inhibits GSK3β. TGF-β1 stimulates the phosphorylation of Smad-3 and subsequent nuclear translocation to activate the transcription of collage 1/III and α-smooth muscle actin (α-SMA). Besides, TGF-β1 stabilizes cytoplasmic β-catenin levels indirectly by phosphorylation of Akt at Thr308-induced inhibition of GSK3β by increasing phosphorylation of Ser9. Exendin-4, and possibly through G protein-coupled receptors (GPCRs), increases levels of cAMP and upregulates β-arrestin-2 levels. Both can result in a positive inotropic effect. Besides, β-arrestin-2 can stimulate PP2A to dephosphorylation Smad3 (inhibition) and GSK3β (activation), thus reduces fibrosis and prevents the activation of β-catenin and collagen deposition.

Role of MnSOD in AIFm2‐Mediated Apoptosis During Cardiac Ischemia/Reperfusion Injury

Role of MnSOD in AIFm2‐Mediated Apoptosis During Cardiac Ischemia/Reperfusion Injury

In vitro transfection of manganese superoxide dismutase small interfering rna suppresses stemness of human breast cancer stem cells (aldehyde dehydrogenase 1-positive): Focus on OCT4 mRNA expression and mammosphere-forming capacity

Introduction: Aldehyde dehydrogenase 1-positive (ALDH1+) breast cancer stem cells (BCSCs) are a small population of tumor cells with high capacity of tumorigenicity and oxidative stress. Manganese superoxide dismutase (MnSOD) is specifically expressed in mitochondria as the primary defense against superoxides, which are one of the causes of oxidative stress in cells. The aim of this study was to determine the impact of suppressing MnSOD expression using small interfering RNA (siRNA) on the stemness, tumorigenicity, and viability of BCSCs. Materials and Methods: In vitro transfection of ALDH1+ BCSCs was performed using 33 and 66 μM specific MnSOD siRNA under standard culture conditions. Total RNA and protein were extracted from the transfected cells using TriPure® Isolation Reagent and RIPA® lysis buffer. Cell viability was measured using a trypan blue exclusion assay. The relative expression of MnSOD and OCT4 mRNAs was analyzed using one-step quantitative reverse transcription polymerase chain reaction. MnSOD activity was determined by xanthine oxidase inhibition assay (RanSOD® kit). Cellular superoxides were measured using a dihydroethidium assay, and tumorigenicity was observed with mammosphere-forming unit. Results: After siRNA incubation for 48 h, MnSOD was suppressed by 0.176-fold (P < 0.01), MnSOD enzyme-specific activity was reduced 70.4%, cellular superoxide levels increased by 1.13-fold, OCT4 expression was suppressed by 1.98-fold (P < 0.05), and mammosphere-forming unit decreased by 36.5% (P < 0.05) compared with the corresponding negative controls. The viability of the ALDH1+ BCSCs was reduced 75% (P < 0.05). Conclusion: Our results suggest that suppression of MnSOD expression may be a promising target to reduce stemness and tumorigenicity of ALDH1+ BCSCs.

Dual-Responsive DNA Nanodevice for the Available Imaging of an Apoptotic Signaling Pathway in Situ.

Fluorescence imaging tools enable the in situ visualization of those molecules involved in various cell signaling pathways, but directly describing these pathways instead of the separate mediators in situ is much more meaningful and still full of challenges. In this work, a dual-responsive DNA nanodevice that allows the available imaging of an apoptotic signaling pathway in living cells has been developed. The nanodevice is constructed through assembling an elaborately designed Y-shaped DNA (Y-DNA) layer on gold nanoparticles (AuNPs). Only if an apoptotic signaling pathway involving the manganese superoxide dismutase (MnSOD) mRNA and downstream cytochrome c (Cyt c) is presented to serve as the input, the nanodevice can perform an "AND" logic gate operation, disassembling the Y-DNA from the AuNP surface and thereafter outputting a fluorescence signal. In comparison with the fluorescence imaging methods that target individual specific molecules, our strategy allows direct profiling of a specific signaling pathway by connected characterization of two correlative targets. The programmable feature of this strategy also shows the potential for the profiling of other signaling pathways. The concept of studying the line connecting two points will contribute to the systematic interrogation on the signaling networks in situ as the networks are composed of lines instead of individual points.

SENSITIVITY OF BREAST CANCER STEM CELLS (CD24-/CD44+) TO DOXORUBICIN IS ASSOCIATED WITH OXIDATIVE STRESS STATUS

Objective: The aim of this study was to analyze the sensitivity of BCSCs to doxorubicin and its association with oxidative stress.&#x0D; Methods: BCSCs (CD24-/CD44+) were treated with doxorubicin every 2 d for 14 d. The determination of cell viability was performed using a trypan blue exclusion assay. The levels of reactive oxygen species (ROS) were measured using a dihydroethidium (DHE) and a 2’,7’-dichlorofluorescein diacetate (DCFH-DA) probes. Manganese superoxide dismutase (MnSOD) mRNA expression and specific activity were also analyzed. Glutathione (GSH) level was measured using Ellman’s method.&#x0D; Results: The viability of the BCSCs decreased after 2 d of treatment with doxorubicin, but started to increase after 8 d. After 8 d of doxorubicin treatment, the ROS level in the BCSCs decreased, while the MnSOD specific activity increased. In addition, the MnSOD mRNA expression and GSH level were suppressed after 8 d of treatment.&#x0D; Conclusion: Doxorubicin treatment induced cytotoxicity after 2 d by increasing the superoxide levels of the BCSCs. After 8 d of treatment, the sensitivity of BCSCs to doxorubicin decreased due to the suppressed oxidative stress from the enhanced antioxidant activity of the MnSOD.

Preventive Effect of Alkaloids from Lotus plumule on Acute Liver Injury in Mice

Lotus plumule is a traditional Chinese food that can be used as a beverage. In this study, three kinds of Lotus plumules from different regions of China were selected to observe the preventive effects of extracted alkaloids on CCl4-induced liver injuries. Animal experiments revealed that alkaloids extracted from Lotus plumules decreased the serum AST (aspartate aminotransferase), ALT (alanine aminotransferase), and TBIL (total bilirubin) levels, enhanced SOD (superoxide dismutase) activity, and reduced MDA (malondialdehyde) level in the liver tissues of mice with liver injury. H&E observation confirmed that alkaloids from Lotus plumules could alleviate CCl4-induced injuries of liver tissues and inhibit the inflammatory effect on hepatocytes. Further qPCR experiments also demonstrated that alkaloids from Lotus plumules upregulated the expression of IκB-α (inhibitor of NF-κB alpha), Cu/Zn-SOD (copper/zinc superoxide dismutase), Mn-SOD (manganese superoxide dismutase), and CAT (catalase) mRNA and downregulated TNF-α (tumor necrosis factor alpha) and NF-κB (nuclear factor kappa B) expression in the liver tissues of mice with liver injury. All three kinds of alkaloids from Lotus plumules could prevent CCl4-induced liver injuries by regulating the levels of oxidative stress and inflammation in mice, and the therapeutic effect was comparable to that of silymarin, the medicine commonly used in the treatment of liver diseases. In summary, alkaloids from Lotus plumules contain bioactive substances with hepatic protective efficacy and possess potential application value in the field of functional food.

Antioxidant response to acute cold exposure and during recovery in juvenile Chinese soft-shelled turtles (Pelodiscus sinensis).

The antioxidant defense protects turtles from oxidative stress caused by adverse environment conditions, such as acute thermal fluctuations. However, it remains unclear how these defenses work. The present study examined changes in key enzymes of the enzymatic antioxidant system and the glutathione (GSH) system at both the mRNA and enzyme activity levels during acute cold exposure and recovery in juvenile Chinese soft-shelled turtles, Pelodiscus sinensis Transcript levels of the upstream regulator NF-E2-related factor 2 (Nrf2) were also measured. Turtles were acclimated at 28°C (3 weeks), then given acute cold exposure (8°C, 12 h) and finally placed in recovery (28°C, 24 h). The mRNA levels of cerebral and hepatic Nrf2 and of genes encoding downstream antioxidant enzymes did not change, whereas levels of nephric Nrf2, manganese superoxide dismutase (MnSOD) and glutathione peroxidase 4 (GPx4) mRNA decreased upon cold exposure. During recovery, Nrf2 mRNA remained stable in all three tissues, hepatic Cu/ZnSOD, MnSOD and catalase (CAT) mRNA levels increased, and nephric MnSOD and GPx4 mRNAs did not change from the values during cold exposure. In the GSH system, mRNA levels of most enzymes remained constant during cold exposure and recovery. Unmatched with changes in mRNA level, high and stable constitutive antioxidant enzyme activities were maintained throughout, whereas GPx activity significantly reduced in the kidney during cold exposure, and in liver and kidney during recovery. Our results suggest that the antioxidant defense regulation in response to acute cold exposure in P. sinensis may not be achieved at the transcriptional level, but may rely mainly on high constitutive antioxidant enzyme activities.

Estradiol ameliorates antioxidant axis SIRT1-FoxO3a-MnSOD/catalase in the heart of fructose-fed ovariectomized rats

Harmful effects of fructose-rich diet (FRD) were predominantly observed in males, suggesting protective effects of estrogens. Little is known about AMPK/sirtuin-1 (SIRT1)/forkhead box O3 (FoxO3a)/manganese superoxide dismutase (MnSOD)/catalase signaling in the heart in state of metabolic syndrome and oxidative stress induced by fructose over-consumption. We investigated the effect of 10% FRD on expression of AMPK-SIRT1-FoxO3a-MnSOD/catalase axis in myocardium and potentially beneficial effect of 17β-estradiol replacement. The expression of NADPH oxidase 4 (Nox4) and miRNA-155, unfavorable regulators of this axis, were also investigated. FRD significantly increased AMPK and decreased FoxO3a activity, decreased SIRT1, MnSOD and Nox4 protein expression while E2 reverted these changes, except for Nox4, and increased catalase protein level. E2 diminished Nox4 and MnSOD mRNA level in FRD ovariectomized rats. These results suggest independent response of AMPK and SIRT to FRD treatment. The proposed signaling in the heart should be further investigated in the prooxidative and antioxidative milieu.

Dietary fructooligosaccharide can mitigate the negative effects of immunity on Chinese mitten crab fed a high level of plant protein diet

An 8-week feeding trial was carried out under controlled condition to evaluate the effect of dietary fructooligosaccharide (FOS) on growth performance, whole body composition, antioxidant status and immunity of crabs fed high levels of plant protein diets. Thus, six experimental diets were formulated (designated as F0P50, F0P60, F0P70, F0.2P50, F0.2P60 and F0.2P70), which contain two FOS levels (0 or 0.2%) and three plant protein levels (50, 60, or 70%) according to a 2 × 3 factorial design. The results showed that weight gain increased significantly as dietary plant protein level decreased from 70% to 50%. At 50% plant protein level, the addition of 0.2% FOS can significantly elevate weight gain (WG) (P < 0.05). The highest value in survival rate was observed in crabs fed F0.2P50 and F0.2P60 diet. Crabs fed F0.2P50 diet showed significantly higher crude protein content (P < 0.05) compared with those in other groups, but there were no significant differences in the contents of moisture, crude lipid and ash among all groups (P > 0.05). Catalase (CAT) activity in crabs fed F0.2P50 increased significantly (P < 0.05) compared with crabs fed F0P60, F0P70, F0.2P60 and F0.2P70, but malondialdehyde (MDA) concentrations decreased significantly (P < 0.05). Meanwhile, nitric oxide (NO) concentration, acid phosphatase (ACP) and alkaline phosphatase (AKP) activities of crabs fed 0.2% FOS diets increased significantly (P < 0.05) compared with crabs fed 0% FOS diets. The expressions of prophenoloxidase (propo) was significantly (P < 0.05) affected only by dietary plant protein levels with the highest values observed in 50% plant protein diet, whereas the opposite was true for Myeloid differentiation factor 88 (myd88). The mRNA expressions of mitochondrial manganese superoxide dismutase (mtmnsod), lipopolysaccharide-induced TNF-α factor (litaf) and toll like receptors (tlrs) were significantly affected (P < 0.05) by both FOS and plant protein levels. The cytosolic manganese superoxide dismutase (cytmnsod) mRNA expressions in F0.2P50 and F0.2P60 groups were significantly higher than those in F0P70 and F0.2P70 groups. The results in this study indicated that supplementation with 0.2% FOS can enhance growth performance in crabs fed lower plant protein diets and as well improve immunity in those fed with higher plant protein diets.

Evaluation and prognostic significance of manganese superoxide dismutase in clear cell renal cell carcinoma

The antioxidant enzyme manganese superoxide dismutase (MnSOD) is up-regulated in renal cell carcinoma (RCC) and has been implicated in multiple stages of RCC tumorigenesis and progression. However, the prognostic significance of MnSOD in RCC has not been fully elucidated. This study aimed to investigate the expression profile of MnSOD in clear cell RCC (ccRCC) tissues and evaluate the clinical significance of this enzyme in ccRCC patients. MnSOD mRNA was assessed in 42 ccRCC and 33 normal kidney tissues using the Oncomine database, and its protein was detected in 145 ccRCCs and 3 normal tissues by immunohistochemistry staining. The Oncomine database confirmed higher MnSOD mRNA expression in ccRCC than in normal tissues, and immunohistochemistry analysis revealed that MnSOD protein expression was inversely associated with pathologic grade, clinical stage, tumor size, M status, and cancer-specific survival. In addition, univariate survival analysis demonstrated that high-grade, late-stage, large tumors, stage M1, and low MnSOD expression were associated with a poorer prognosis for cancer-specific survival, and further multivariate analysis revealed that tumor grade, stage, M1 stage, and MnSOD were identified as independent prognostic factors for cancer-specific survival in patients with ccRCC. Collectively, these findings imply that MnSOD is a promising prognostic marker in ccRCC and implies that oxidative stress might be involved in the tumorigenesis and progression of ccRCC.