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Analyzing the SOD-like activity of nanozymes in vitro is of great importance for identifying new nanozymes and predicting their potential biological effects in vivo. However, false negative or positive results occasionally occur d...
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Analyzing the SOD-like activity of nanozymes in vitro is of great importance for identifying new nanozymes and predicting their potential biological effects in vivo. However, false negative or positive results occasionally occur due to the mismatch between the detection methods and nanozymes. Here, five typical SOD-like nanozymes, including CeO_2, Mn_3O_4, Prussian blue (PB), PCN222-Mn, and Pt NPs, have been used to evaluate the sensitivity and accuracy of several commonly used in vitro detection methods. By systematically analyzing the detection results, several precautions have been taken. (1) The hydroethidine (HE) probe could be disturbed by the nanozyme with oxidative ability. (2) The nitro blue tetrazolium (NBT) probe has a moderate sensitivity due to the poor water solubility of its reduced product. (3) The water-soluble tetrazolium salt (WST)-8 probe has a higher sensitivity than both NBT and iodonitrotetrazolium chloride (INT). (4) The detection system using the irradiation of riboflavin to produce ?O_2~? might be interfered by the nanozyme with photosensibility. (5) Both the quality of DMPO and incubation time are important factors for electron paramagnetic resonance (EPR) measurement. This study will be useful for choosing more suitable in vitro detection methods of SOD-like activity for nanozymes in the future.
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Various raw materials are used to produce vinegars that contain functional compounds associated with disease prevention. We evaluated changes in functional compounds during tomato vinegar production and superoxide dismutase-like a...
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Various raw materials are used to produce vinegars that contain functional compounds associated with disease prevention. We evaluated changes in functional compounds during tomato vinegar production and superoxide dismutase-like activity of tomato vinegar. Tomato vinegar contained abundant anti-hypertensive compounds, e.g., -aminobutyric acid and potassium derived from tomatoes and acetic acid and pyroglutamic acid produced during fermentation. It had stronger superoxide dismutase-like activity than commercial vinegars because of tomato-derived superoxide dismutase-like compounds, including phenolic acids, flavonoids, and glutathione. These data indicate that tomato vinegar is a candidate dietary supplement with potential preventive effects against cardiovascular diseases due to its anti-hypertensive and superoxide dismutase-like compounds.
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Pathogenic bacteria infections have posed a threat to human health worldwide. Nanomaterials with natural enzymatic activity provide an opportunity for the development of new antibacterial pathways. We successfully constructed iron...
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Pathogenic bacteria infections have posed a threat to human health worldwide. Nanomaterials with natural enzymatic activity provide an opportunity for the development of new antibacterial pathways. We successfully constructed iron phosphate nanozyme-hydrogel (FePO4-HG) with the traits of positive charge and macropores. Interestingly, FePO4-HG displayed not only peroxidase-like activity under acidic bacterial infectious microenvironment but also superoxide dismutase-catalase-like synergistic effects in neutral or weak alkaline conditions, thus protecting normal tissues from the peroxidase-like protocol with exogenous H2O2 damage. Furthermore, the positive charge and macropore structure of FePO4-HG could capture and restrict bacteria in the range of ROS destruction. Obviously, FePO4-HG exhibited excellent antibacterial ability against MRSA and AREC with the assistance of H2O2. Significantly, the FePO4-HG + H2O2 system could efficiently disrupt the bacterial biofilm formation and facilitate the glutathione oxidation process to rapid bacterial death with low cytotoxicity. Moreover, FePO4-HG was unsusceptible to bacterial resistance development in MRSA. Animal experiments showed that the FePO4-HG + H2O2 group could efficiently eliminate the MRSA infection and present excellent wound healing without inflammation and tissue adhesions. With further development and optimization, FePO4-HG has great potential as a new class of antibacterial agents to fight antibiotic-resistant pathogens.
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Previously, we reported that an optimal dose of lipopolysaccharide (LPS) markedly extends the life span of mouse primary-cultured microglia by suppressing apoptotic and autophagic cell death pathways. The aim of the present study ...
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Previously, we reported that an optimal dose of lipopolysaccharide (LPS) markedly extends the life span of mouse primary-cultured microglia by suppressing apoptotic and autophagic cell death pathways. The aim of the present study was to assess how these cells protect themselves against reactive oxygen species (ROS) generated by LPS treatment. The study was conducted in microglia obtained from murine neonate brain, which are destined to die within a few days under ordinary culture conditions. The generation of ROS was maximal after 15 h LPS treatment (1 ng/mL LPS and 100 ng/mL LPS). The expression of inducible nitric oxide (NO) synthase protein was significantly increased by Day 1 of LPS treatment and was followed by the production of NO. The expression of either Cu/Zn- or Mn-superoxide dismutase protein (SOD) was also increased by 16 h and Day 1 of LPS treatment. LPS did not affect the expression of Cu/Zn- and Mn-SOD proteins, nor did it extend the life span of microglia that had mutated Toll-like receptor (TLR) 4. The findings of the present study suggest that SODs function as a potent barrier to overcome ROS generated in primary-cultured microglia following LPS treatment and that TLR4 may be significantly involved in inducing these proteins. The microglia may be able to protect themselves against oxidative stress, allowing them to live for more than 1 month. Because long-lived microglia may play a critical role in the exacerbation of neurodegeneration, bringing activated microglia back to their resting stage could be a new and promising strategy to inhibit the deterioration underlying neurodegenerative disorders.
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Chitinase-3-like protein 1 (CHI3L1), which is secreted by immune and inflammatory cells, is associated with several inflammatory diseases. However, the basic cellular pathophysiological functions of CHI3L1 are not well characteriz...
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Chitinase-3-like protein 1 (CHI3L1), which is secreted by immune and inflammatory cells, is associated with several inflammatory diseases. However, the basic cellular pathophysiological functions of CHI3L1 are not well characterized. To investigate the novel pathophysiological function of CHI3L1, we performed LC-MS/MS analysis of cells transfected with Myc-vector and Myc-CHI3L1. We analyzed the changes in the protein distribution in Myc-CHI3L1 transfected-cells, and identified 451 differentially expressed proteins (DEPs) compared with Myc-vector-transfected-cells. The biological function of the 451 DEPs was analyzed and it was found that the proteins with endoplasmic reticulum (ER)-associated function were much more highly expressed in CHI3L1-overexpressing cells. We then compared and analyzed the effect of CHI3L1 on the ER chaperon levels in normal lung cells and cancer cells. We identified that CHI3L1 is localized in the ER. In normal cells, the depletion of CHI3L1 did not induce ER stress. However, the depletion of CHI3L1 induces ER stress and eventually activates the unfolded protein response, especially the activation of Protein kinase R-like endoplasmic reticulum kinase (PERK), which regulates protein synthesis in cancer cells. CHI3L1 may not affect ER stress owing to the lack of misfolded proteins in normal cells, but instead activate ER stress as a defense mechanism only in cancer cells. Under ER stress conditions induced by the application of thapsigargin, the depletion of CHI3L1 induces ER stress through the upregulation of PERK and PERK downstream factors (eIF2α and ATF4) in both normal and cancer cells. However, these signaling activations occur more often in cancer cells than in normal cells. The expression of Grp78 and PERK in the tissues of patients with lung cancer was higher compared with healthy tissues. It is well known that ER stress-mediated PERK-eIF2α-ATF4 signaling activation causes apoptotic cell death. ER stress-mediated apoptosis induced by the depletion of CHI3L1 occurs in cancer cells, but rarely occurs in normal cells. Consistent with results from the in vitro model, ER stress-mediated apoptosis was greatly increased during tumor growth and in the lung metastatic tissue of CHI3L1-knockout (KO) mice. The analysis of “big data” identified superoxide dismutase-1 (SOD1) as a novel target of CHI3L1 and interacted with CHI3L1. The depletion of CHI3L1 increased SOD1 expression, resulting in ER stress. Furthermore, the depletion of SOD1 reduced the expression of ER chaperones and ER-mediated apoptotic marker proteins, as well as apoptotic cell death induced by the depletion of CHI3L1 in in vivo and in vitro models. These results suggest that the depletion of CHI3L1 increases ER stress-mediated apoptotic cell death through SOD1 expression, and subsequently inhibits lung metastasis.
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Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease that is characterized by the loss of motor neurons, which results in progressive muscle atrophy. The pathology spreads from the initial site of onset to con...
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Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease that is characterized by the loss of motor neurons, which results in progressive muscle atrophy. The pathology spreads from the initial site of onset to contiguous anatomic regions. Mutations in the gene encoding Cu/Zn-superoxide dismutase (SOD1) have been identified in a dominantly inherited form of ALS (ALS-5OD1). A major hallmark of ALS-SOD1 is the abnormal accumulation of conformationally aberrant SOD1 protein (z.e., misfolded SOD1) within motor neurons. Emerging experimental evidence has suggested that misfolded proteins associated with neurodegenerative diseases exhibit prion-like properties, i.e., misfolded proteins act as conformational templates that convert normal proteins into a pathogenic form. Possibly as a result of this prion-like self-propagation property, misfolded forms of pathological proteins are considered to accumulate in the central nervous system and cause neurodegeneration. In this article, we review recent evidence for the role of prion-like mechanisms in ALS-SODL In particular, we discuss the propensity of misfolded SOD1 to act as a pathological seed, spread between cells, and propagate neuroanatomically.
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Motor neurons containing aggregates of superoxide dismutase 1 (SOD1) are hallmarks of amyotrophic lateral sclerosis (ALS) caused by mutations in the gene encoding SOD1. We have previously reported that two strains of mutant human ...
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Motor neurons containing aggregates of superoxide dismutase 1 (SOD1) are hallmarks of amyotrophic lateral sclerosis (ALS) caused by mutations in the gene encoding SOD1. We have previously reported that two strains of mutant human (h) SOD1 aggregates (denoted A and B) can arise in hSOD1-transgenic models for ALS and that inoculation of such aggregates into the lumbar spinal cord of mice results in rostrally spreading, templated hSOD1 aggregation and premature fatal ALS-like disease. Here, we explored whether mutant hSOD1 aggregates with prion-like properties also exist in human ALS. Aggregate seeds were prepared from spinal cords from an ALS patient carrying the hSOD1(G127Gfs*7) truncation mutation and from mice transgenic for the same mutation. To separate from mono-, di- or any oligomeric hSOD1 species, the seed preparation protocol included ultracentrifugation through a density cushion. The core structure of hSOD1(G127Gfs*7) aggregates present in mice was strain A-like. Inoculation of the patient- or mouse-derived seeds into lumbar spinal cord of adult hSOD1-expressing mice induced strain A aggregation propagating along the neuraxis and premature fatal ALS-like disease (p<0.0001). Inoculation of human or murine control seeds had no effect. The potencies of the ALS patient-derived seed preparations were high and disease was initiated in the transgenic mice by levels of hSOD1(G127Gfs*7) aggregates much lower than those found in the motor system of patients carrying the mutation. The results suggest that prion-like growth and spread of hSOD1 aggregation could be the primary pathogenic mechanism, not only in hSOD1 transgenic rodent models, but also in human ALS.
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Seeds of double low oilseed rape variety Mango (Brassica napus, var. oleifera) were subjected to a 7-day germination at 25℃ and 95% moisture content in darkness in a conditioning cabinet. The effects of the germination process on...
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Seeds of double low oilseed rape variety Mango (Brassica napus, var. oleifera) were subjected to a 7-day germination at 25℃ and 95% moisture content in darkness in a conditioning cabinet. The effects of the germination process on the superoxide dismutase-like activity (SOD-like activity), thiamine (vitamin B_1) and riboflavin (vitamin B_2) and minerals, such as Ca, Mg, Cu, Fe and Mn, were studied. Correlations between individual mineral contents, vitamin B_1 and B_2 contents, and the ability of phosphate buffered saline (PBS) extracts from germinated rapeseed to scavenge superoxide anion radicals in vitro were also investigated. SOD-like activity showed a gradual increase after the second day of germination, reaching a maximum level on the sixth day, and remained almost constant up to the end of the germination period. During germination, thiamine underwent a progressive decrease up to the sixth day, reaching a constant level between the sixth and the seventh day. In contrast, riboflavin content increased throughout the germination period up to the fifth day, and after that a constant level was observed. Levels of Ca and Mg were almost constant up to the fourth day and after that an increase of these minerals was observed. Cu and Mn increased during the germination process, and retentions of 33% and 22%, respectively, were observed at the end of germination. Fe content dropped after 1 day of germination and from there onward it started to increase gradually and an 18% retention was observed in 7-day germinated seeds. Positive correlations between SOD-like activity and riboflavin (r = 0.87), Cu (r = 0.74) and Mn (r = 0.87) were found during rapeseed germination.
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The purpose of this experiment was to evaluate the superoxide dismutase (SOD)-like activity of boar seminal plasma, the change of SOD-like activity in the semen stored in Modena extender during preservation and to clarify the effe...
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The purpose of this experiment was to evaluate the superoxide dismutase (SOD)-like activity of boar seminal plasma, the change of SOD-like activity in the semen stored in Modena extender during preservation and to clarify the effect of addition of SOD to Modena extender on the motility of boar spermatozoa. The SOD-like activity was measured by Electron Spin Resonance Spectroscopy. The SOD-like activities of semina plasma of boar A and B were 9.7+-0.9#mu#/ml and 6.1+-0.2#mu#/ml, respectively. The SOD-like activity in the semen diluted with Modena extender did not change during the storage peiod of 28 days at 10 deg C. The addition of SOD to the extended semen improved sperm viability during storage of 28 days and the best result was obtained from the spermatozoa suspended in Modena extender added 800#mu#/ml of SOD. The results suggest that the addition of SOD to Modena extender is useful for long-term maintenance of good motility in liquid storage of boar spermatozoa.
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