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1.
Int Immunopharmacol ; 133: 112095, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38678668

ABSTRACT

BACKGROUND: Adenosine A3 receptor (A3R) exerts analgesic, anti-inflammatory, and anti-nociceptive effects. In this study, we determined the analgesic mechanism of manual acupuncture (MA) in rats with complete Freund's adjuvant (CFA)-induced arthritis and explored whether MA ameliorates inflammation in these rats by upregulating A3R. METHODS: Sixty Sprague Dawley (SD) rats were randomly divided into the following groups: Control, CFA, CFA + MA, CFA + sham MA, CFA + MA + DMSO, CFA + MA + IB-MECA, and CFA + MA + Reversine groups. The arthritis rat model was induced by injecting CFA into the left ankle joints. Thereafter, the rats were subjected to MA (ST36 acupoint) for 3 days. The clinical indicators paw withdrawal latency (PWL), paw withdrawal threshold (PWT), and open field test (OFT) were used to determine the analgesic effect of MA. In addition, to explore the effect of A3R on inflammation after subjecting arthritis rats to MA, IB-MECA (A3R agonist) and Reversine (A3R antagonist) were injected into ST36 before MA. RESULTS: MA ameliorated the pathological symptoms of CFA-induced arthritis, including the pain indicators PWL and PWT, number of rearing, total ambulatory distance, and activity trajectory. Furthermore, after MA, the mRNA and protein expression of A3R was upregulated in CFA-induced arthritis rats. In contrast, the protein levels of TNF-α, IL-1ß, Rap1, and p-p65 were downregulated after MA. Interestingly, the A3R agonist and antagonist further downregulated and upregulated inflammatory cytokine expression, respectively, after MA. Furthermore, the A3R antagonist increased the degree of ankle swelling after MA. CONCLUSION: MA can alleviate inflammatory pain by inhibiting the NF-κB signaling pathway via upregulating A3R expression of the superficial fascia of the ST36 acupoint site in CFA-induced arthritis rats.


Subject(s)
Acupuncture Therapy , Arthritis, Experimental , Freund's Adjuvant , Rats, Sprague-Dawley , Receptor, Adenosine A3 , Up-Regulation , Animals , Receptor, Adenosine A3/metabolism , Receptor, Adenosine A3/genetics , Arthritis, Experimental/therapy , Rats , Male , Inflammation , Pain/drug therapy , Acupuncture Points , Pain Management/methods
2.
Biosens Bioelectron ; 240: 115640, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37651947

ABSTRACT

Paraquat (PQ) is a typical biotoxic small molecule. Knowledge of how to directly introduce it into cyclic amplification rather than transform it into a secondary target is lacking in current analytical methods. Considering the urgent need for trace pesticide residue detection and the inherent defects of small molecule analysis, a CRISPR/Cas12a-driven small molecule-induced dual-cycle strategy was developed based on the immune competition method. The key to signal amplification is the mutual activation and acceleration between Cycle 1 triggered by the small molecule and Cycle 2 driven by CRISPR/Cas12a. Impressively, small molecules have been successfully incorporated into the dual-cycle strategy, which achieves a low detection limit (3.1 pg/mL) and a wide linear range (from 10 pg/mL to 50 µg/mL). Moreover, the designed biosensor was successfully employed to evaluate the PQ residual level in real samples and showed effective implementation for the bioanalysis of small molecule targets and pesticide residue-related food safety.


Subject(s)
Biosensing Techniques , Pesticide Residues , Paraquat , Food Safety
3.
Adv Sci (Weinh) ; 10(7): e2203869, 2023 03.
Article in English | MEDLINE | ID: mdl-36642847

ABSTRACT

Cadmium (Cd) is a high-risk pathogenic toxin for hepatic diseases. Excessive mitophagy is a hallmark in Cd-induced hepatotoxicity. However, the underlying mechanism remains obscure. Mitochondrial calcium uniporter (MCU) is a key regulator for mitochondrial and cellular homeostasis. Here, Cd exposure upregulated MCU expression and increased mitochondrial Ca2+ uptake are found. MCU inhibition through siRNA or by Ru360 significantly attenuates Cd-induced excessive mitophagy, thereby rescues mitochondrial dysfunction and increases hepatocyte viability. Heterozygous MCU knockout mice exhibit improved liver function, ameliorated pathological damage, less mitochondrial fragmentation, and mitophagy after Cd exposure. Mechanistically, Cd upregulates MCU expression through phosphorylation activation of cAMP-response element binding protein at Ser133(CREBS133 ) and subsequent binding of MCU promoter at the TGAGGTCT, ACGTCA, and CTCCGTGATGTA regions, leading to increased MCU gene transcription. The upregulated MCU intensively interacts with voltage-dependent anion-selective channel protein 1 (VDAC1), enhances its dimerization and ubiquitination, resulting in excessive mitophagy. This study reveals a novel mechanism, through which Cd upregulates MCU to enhance mitophagy and hepatotoxicity.


Subject(s)
Cadmium , Calcium Channels , Chemical and Drug Induced Liver Injury , Mitochondrial Proteins , Mitophagy , Voltage-Dependent Anion Channel 1 , Animals , Mice , Cadmium/toxicity , Calcium Channels/genetics , Calcium Channels/metabolism , Chemical and Drug Induced Liver Injury/metabolism , Dimerization , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Mitophagy/genetics , Mitophagy/physiology , Ubiquitination , Up-Regulation , Voltage-Dependent Anion Channel 1/metabolism
4.
Thorac Cancer ; 12(1): 8-12, 2021 01.
Article in English | MEDLINE | ID: mdl-33225621

ABSTRACT

Malignant pleural mesothelioma (MPM) is a type of cancer originating from the pleura with high aggressiveness and poor prognosis. A timely diagnosis is crucial to improve its prognosis. Laboratory biomarkers have significant advantages of reduced invasiveness, low cost, and are observer-independent, and therefore represent a promising diagnostic tool for MPM. MicroRNA is a family of non-coding RNA that regulates gene expression at the post-transcriptional level. Accumulated studies showed that microRNA, either in tissue, circulating, and body fluid, has potential diagnostic value for various disorders. Here, we reviewed the diagnostic value of microRNA for MPM.


Subject(s)
Mesothelioma, Malignant/genetics , MicroRNAs/genetics , Pleural Neoplasms/genetics , Humans
5.
Ann Transl Med ; 8(9): 601, 2020 May.
Article in English | MEDLINE | ID: mdl-32566627

ABSTRACT

BACKGROUND: Whether routine urinary analysis has a net benefit for urinary tract infection (UTI) screening is unclear. METHODS: Using the laboratory information system (LIS), we retrospectively extracted the data of urine culture and routine analysis between January 2017 and April 2017. Receiver operating characteristic (ROC) curve, logistic regression model, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were used to estimate the screening performance of routine urinary analysis. Decision curve analysis (DCA) was used to estimate the net benefit of routine urinary analysis. RESULTS: A total of 927 specimens with 156 UTIs were included in the present study. The area under ROC curves (AUCs) of white blood cells (WBCs) and bacteria were 0.729 and 0.836, respectively. The logistic regression model incorporating WBCs, bacteria and nitrite together had an AUC of 0.851, which is significantly higher than that of WBCs. NRI and IDI analyses also indicated that WBCs, bacteria and nitrite, when used together, had better a screening performance than each single test alone. DCA revealed that 0.08 net benefit can be obtained for bacteria and the model, while the net benefit of WBCs is limited. CONCLUSIONS: WBCs, bacteria and nitrite, when used together, can significantly improve the efficiency for UTI screening. Bacteria and the model incorporating WBCs, bacteria and nitrite have a net benefit in UTI screening, while the net benefit of WBCs, when used alone, is limited.

6.
Dis Markers ; 2019: 6891537, 2019.
Article in English | MEDLINE | ID: mdl-31281548

ABSTRACT

Non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is the leading cause of morbidity and mortality from cardiovascular disease worldwide. Several recent studies have shown the relationship between the triglyceride-glucose (TyG) index and vascular disease; however, the role of the TyG index in NSTE-ACS has not been extensively assessed. Thus, we aimed to investigate the association of the TyG index with cardiovascular risk factors and outcomes in NSTE-ACS. Overall, 438 patients with NSTE-ACS were enrolled to examine the association of the TyG index with the SYNTAX score and major adverse cardiovascular events (MACEs). The TyG index was calculated as ln (fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2). The severity of coronary lesions was quantified by the SYNTAX score. MACEs included cardiac death, nonfatal myocardial infarction, target vessel revascularization, congestive heart failure, and nonfatal stroke. All the patients underwent a 12-month follow-up for MACEs after admission. Multivariate regression analysis identified metabolic risk factors as independent parameters correlated with the TyG index. The prevalence of glucose metabolism disorder, metabolic syndrome, and MACEs increased with increasing TyG index. The TyG index showed a strong diagnostic performance for cardiovascular risk factors and was independently associated with the SYNTAX score (OR 6.055, 95% CI 2.915-12.579, P < 0.001). The risk of MACEs (12.8% and 22.8% for the low TyG index and high TyG index groups, respectively; adjusted HR = 1.791, 95% CI 1.045-3.068, P = 0.034) significantly increased in the high TyG index group as compared with the low TyG index group. The multivariate Cox regression analysis further revealed that the TyG index was an independent predictor of MACEs (HR 1.878, 95% CI 1.130-3.121, P = 0.015). In conclusion, the TyG index might be an independent predictor of coronary artery disease severity and cardiovascular outcomes in NSTE-ACS.


Subject(s)
Acute Coronary Syndrome/blood , Blood Glucose/analysis , Coronary Artery Disease/blood , Triglycerides/blood , Acute Coronary Syndrome/pathology , Aged , Biomarkers/blood , Coronary Artery Disease/pathology , Electrocardiography , Female , Humans , Male , Middle Aged
7.
Clin Exp Metastasis ; 36(1): 39-56, 2019 02.
Article in English | MEDLINE | ID: mdl-30617444

ABSTRACT

Most lung cancer bone metastasis are characterized by osteolytic destruction and osteoblastic activity is significantly decreased, suggesting that hypoxia may play a critical role in the process, but the underlying mechanisms remain unknown. Semaphorin 4D (Sema4D) is a recently discovered osteogenic inhibitory factor that is expressed at high levels in lung cancers. Here, CoCl2-induced hypoxia significantly enhanced the inhibitory effect of lung cancer cell conditioned media on osteoblast differentiation by inducing the expression and secretion of Sema4D in a HIF-1α- but not HIF-2α-dependent manner. Moreover, HIF-1α directly regulated Sema4D expression by binding to bases 1171 to 798 in the Sema4D promoter. Furthermore, hypoxia increased Sema4D secretion by upregulating a disintegrin and metalloproteinase 17 (ADAM17) expression in lung cancer in a HIF-1α-dependent manner. In bone metastasis samples from 49 patients with lung cancer, Sema4D and ADAM17 expression significantly correlated with HIF-1α expression and strongly correlated with a poor differentiation status and osteolytic bone destruction. These results provide the first evidence that HIF-1α-induced Sema4D expression and secretion play important roles in lung cancer osteolytic bone metastasis by inhibiting osteoblast differentiation, thereby providing potential strategies for the treatment of bone metastasis via targeting osteoblasts.


Subject(s)
Adenocarcinoma/pathology , Antigens, CD/metabolism , Bone Neoplasms/secondary , Carcinoma, Squamous Cell/pathology , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Lung Neoplasms/pathology , Osteogenesis , Semaphorins/metabolism , ADAM17 Protein/genetics , ADAM17 Protein/metabolism , Adenocarcinoma/metabolism , Adenocarcinoma/surgery , Antigens, CD/genetics , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Bone Neoplasms/metabolism , Bone Neoplasms/surgery , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/surgery , Culture Media, Conditioned/pharmacology , Female , Follow-Up Studies , Gene Expression Regulation, Neoplastic , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/surgery , Male , Middle Aged , Osteoblasts/drug effects , Osteoblasts/metabolism , Osteoblasts/pathology , Prognosis , Semaphorins/genetics , Tumor Cells, Cultured
8.
Zhonghua Gan Zang Bing Za Zhi ; 21(4): 279-84, 2013 Apr.
Article in Chinese | MEDLINE | ID: mdl-24021790

ABSTRACT

OBJECTIVE: To determine the differential protein expressions of epithelial mesenchymal transition (EMT) markers E-cadherin and vimentin in hepatocellular carcinorma (HCC) and to investigate their correlation to the molecular mechanisms of metastasis to explore their potential utility as prognostic indicators of HCC. METHODS: Tumor tissues and patient-matched adjacent non-tumor tissues were collected from individuals diagnosed with HCC. E-cadherin and vimentin protein expressions in the tissue specimens were quantified by western blot with densitometry of fluorescence emission and comparatively analyzed to determine the associations with molecular and clinical features. The expressions of E-cadherin and vimentin, as well as the other EMT-related protein Twist, were also detected in the tissue specimens by immunohistochemistry. Statistical analyses were carried out by paired-samples t-test, Mann-Whitney test, and Spearman rank correlation analysis. RESULTS: E-cadherin expression was significantly lower in tumor tissues (0.082 +/- 0.063 vs. adjacent non-tumor tissues: 0.226 +/- 0.215, t = -4.050, P less than 0.01), lower in patients with portal vein tumor thrombus (vs. non-thrombic HCC patients, P = 0.001), and correlated with TNM stage (III/IV > I/II, P = 0.003). Vimentin expression was significantly higher in tumor tissues (vs. adjacent non-tumor tissues, P = 0.002), negatively correlated with E-cadherin expression (t = -0.509, P = 0.004), and closely associated with some clinical parameters, such as portal vein tumor thrombus (P less than 0.01), TNM stage (P less than 0.01), and Milan criteria (P = 0.005). Immunohistochemistry showed that E-cadherin expression was very weak in tumors but very strong in the cell membranes of non-tumor tissues, and that vimentin and Twist expressions were strong in tumors but undetectable in non-tumor tissue. CONCLUSION: Expression levels of the EMT markers E-cadherin and vimentin in HCC are related to clinical parameters, including portal vein tumor thrombus and TNM stage, and may represent useful prognostic markers of metastasis.


Subject(s)
Carcinoma, Hepatocellular , Epithelial-Mesenchymal Transition , Biomarkers, Tumor , Cadherins , Humans , Liver Neoplasms , Vimentin
9.
Int J Radiat Biol ; 89(11): 993-1001, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23952262

ABSTRACT

PURPOSE: To evaluate whether exposure to mobile phone radiation (MPR) can induce DNA damage in male germ cells. MATERIALS AND METHODS: A mouse spermatocyte-derived GC-2 cell line was exposed to a commercial mobile phone handset once every 20 min in standby, listen, dialed or dialing modes for 24 h. DNA damage was determined using an alkaline comet assay. RESULTS: The levels of DNA damage were significantly increased following exposure to MPR in the listen, dialed and dialing modes. Moreover, there were significantly higher increases in the dialed and dialing modes than in the listen mode. Interestingly, these results were consistent with the radiation intensities of these modes. However, the DNA damage effects of MPR in the dialing mode were efficiently attenuated by melatonin pretreatment. CONCLUSIONS: These results regarding mode-dependent DNA damage have important implications for the safety of inappropriate mobile phone use by males of reproductive age and also suggest a simple preventive measure: Keeping mobile phones as far away from our body as possible, not only during conversations but during 'dialed' and 'dialing' operation modes. Since the 'dialed' mode is actually part of the standby mode, mobile phones should be kept at a safe distance from our body even during standby operation. Furthermore, the protective role of melatonin suggests that it may be a promising pharmacological candidate for preventing mobile phone use-related reproductive impairments.


Subject(s)
Cell Phone , DNA Damage , Melatonin/pharmacology , Radiation-Protective Agents/pharmacology , Radio Waves/adverse effects , Spermatocytes/drug effects , Spermatocytes/radiation effects , Animals , Cell Line , Electromagnetic Fields/adverse effects , Male , Mice , Spermatocytes/cytology , Spermatocytes/metabolism , Time Factors
10.
Neurotoxicology ; 38: 9-16, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23727075

ABSTRACT

The oral ingestion of soluble nickel compounds leads to neurological symptoms in humans. Deficiencies in aerobic metabolism induced by neurotoxic stimulus can cause an energy crisis in the brain that results in a variety of neurotoxic effects. In the present study, we focused on the aerobic metabolic states to investigate whether disturbance of aerobic metabolism was involved in nickel-induced neurological effects in mice. Mice were orally administered nickel chloride, and neurobehavioral performance was evaluated using the Morris water maze and open field tests at different time points. Aerobic metabolic states in the cerebral cortex were analyzed at the same time points at which neurobehavioral changes were evident. We found that nickel exposure caused deficits in both spatial memory and exploring activity in mice and that nickel was deposited in their cerebral cortex. Deficient aerobic metabolism manifested as decreased O2 consumption and ATP concentrations, lactate and NADH accumulation, and oxidative stress. Meanwhile, the activity of prototypical iron-sulfur clusters (ISCs) containing enzymes that are known to control aerobic metabolism, including complex I and aconitase, and the expression of ISC assembly scaffold protein (ISCU) were inhibited following nickel deposition. Overall, these data suggest that aerobic metabolic disturbances, which accompanied the neurobehavioral changes, may participate in nickel-induced neurologic effects. The inactivation of ISC containing metabolic enzymes may result in the disturbance of aerobic metabolism. A better understanding of how nickel impacts the energy metabolic processes may provide insight into the prevention of nickel neurotoxicity.


Subject(s)
Brain/drug effects , Brain/metabolism , Exploratory Behavior/drug effects , Maze Learning/drug effects , Nickel/toxicity , Aconitate Hydratase/metabolism , Adenosine Triphosphate/metabolism , Aerobiosis/drug effects , Animals , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Down-Regulation , Iron-Sulfur Proteins/metabolism , Lactic Acid/metabolism , Male , Mice , NAD/metabolism , Oxidative Stress , Oxygen Consumption/drug effects
11.
Mutat Res ; 752(1-2): 57-67, 2013 Apr 15.
Article in English | MEDLINE | ID: mdl-23402883

ABSTRACT

Bisphenol A (BPA) is a well-known endocrine-disrupting chemical (EDC) that has received particular attention because of its widespread distribution in humans. Due to its chemical similarity to diethylstilbestrol, which is carcinogenic to mammals, the possible genotoxicity of BPA has already largely been evaluated. However, the results are still inconclusive and controversial. To investigate the genotoxic effects of BPA in rat germ cells and the potential protective action of melatonin against these effects, adult male Sprague-Dawley rats were orally administered BPA at a dose of 200mg/kg body weight per day for ten consecutive days with or without melatonin pretreatment. The thiobarbituric acid reactive substances (TBARS) level and superoxide dismutase (SOD) activity in the testes were evaluated. Subsequently, their spermatocytes were isolated, and DNA damage was assessed using an alkaline comet assay and the meiotic spread method. BPA administration did not significantly affect the weights of rats and their reproductive organs, and no alteration in sperm count was found. However, we demonstrated that BPA administration induced a significant increase in TBARS levels and a decrease in SOD activity that were concomitant with an increase in DNA migration within male germ cells and γH2AX foci formation on the autosomes of pachytene spermatocytes. Furthermore, a decrease in the proportion of 4C-cells was observed. These BPA effects were significantly alleviated by melatonin pretreatment. Nevertheless, the genotoxic effects of BPA were not accompanied by apoptosis in germ cells and morphological changes in the testes. These results indicate that BPA exposure may induce DNA damage accumulation in germ cells via oxidative stress. Moreover, melatonin may be a promising pharmacological candidate for preventing the potential genotoxicity of BPA following occupational or environmental exposure.


Subject(s)
Antioxidants/pharmacology , Benzhydryl Compounds/toxicity , DNA Damage/drug effects , Melatonin/pharmacology , Mutagens/toxicity , Phenols/toxicity , Spermatozoa/drug effects , Animals , Benzhydryl Compounds/antagonists & inhibitors , Male , Oxidative Stress , Phenols/antagonists & inhibitors , Rats , Rats, Sprague-Dawley
12.
Free Radic Biol Med ; 52(9): 1543-51, 2012 May 01.
Article in English | MEDLINE | ID: mdl-22306509

ABSTRACT

Oxidative stress and mitochondrial dysfunction are involved in the pathogenesis of chronic liver cholestasis. Mitochondrial DNA (mtDNA) is highly susceptible to oxidative stress and mtDNA damage leads to mitochondrial dysfunction. This study aimed to investigate the mtDNA alterations that occurred during liver injury in patients with extrahepatic cholestasis. Along with an increase in malondialdehyde (MDA) levels and a decrease in ATP levels, extrahepatic cholestatic patients presented a significant increase in mitochondrial 8-hydroxydeoxyguanosine (8-OHdG) levels and decreases in mtDNA copy number, mtDNA transcript levels, and mtDNA nucleoid structure. In L02 cells, glycochenodeoxycholic acid (GCDCA) induced similar damage to the mtDNA and mitochondria. In line with the mtDNA alterations, the mRNA and protein levels of mitochondrial transcription factor A (TFAM) were significantly decreased both in cholestatic patients and in GCDCA-treated L02 cells. Moreover, overexpression of TFAM could efficiently attenuate the mtDNA damage induced by GCDCA in L02 cells. However, without its C-tail, ΔC-TFAM appeared less effective against the hepatotoxicity of GCDCA than the wild-type TFAM. Overall, our study demonstrates that mtDNA damage is involved in liver damage in extrahepatic cholestatic patients. The mtDNA damage is attributable to the loss of TFAM. TFAM has mtDNA-protective effects against the hepatotoxicity of bile acid during cholestasis.


Subject(s)
Cholestasis, Extrahepatic/genetics , DNA Damage , DNA, Mitochondrial/genetics , DNA-Binding Proteins/physiology , Liver/injuries , Mitochondrial Proteins/physiology , Transcription Factors/physiology , Adenosine Triphosphate/metabolism , Adult , Base Sequence , Blotting, Western , DNA Primers , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Oxidative Stress , Real-Time Polymerase Chain Reaction
13.
Neurochem Int ; 60(3): 233-42, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22226842

ABSTRACT

Tau protein, a microtubule-associated protein involved in a number of neurological disorders such as Alzheimer's disease (AD), may undergo modifications under both physiological and pathological conditions. However, the signaling pathways that couple tau protein to neuronal physiology such as synaptic plasticity have not yet been elucidated. Here we report that tau protein is involved in morphological plasticity in response to brain derived neurotrophic factor (BDNF). Stimulation of the cultured rat hippocampal neurons with BDNF resulted in increased tau protein expression, as detected by Western blotting. Furthermore, tau protein accumulated in the distal region of the neurite when treated with taxol or taxol plus BDNF. The increased tau protein also protected neurons against nocodazole-induced dendrite loss. Moreover, BDNF promoted spine growth as well as tau protein over-expression. Knockdown of tau protein using specific short-hairpin RNA (shRNA) significantly decreased the spine density. And BDNF could not increase the spine density of tau-knockdown neurons. These results highlight a possible role for tau protein in the dynamic rearrangement of cytoskeletal fibers vital for BDNF-induced synaptic plasticity.


Subject(s)
Brain-Derived Neurotrophic Factor/pharmacology , Hippocampus/cytology , Hippocampus/drug effects , Neuronal Plasticity/drug effects , Neurons/drug effects , Neurons/ultrastructure , tau Proteins/physiology , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents, Phytogenic/pharmacology , Blotting, Western , Cells, Cultured , Dendritic Spines/drug effects , Dendritic Spines/ultrastructure , Fluorescent Antibody Technique , Gene Silencing/drug effects , Immunohistochemistry , Neurites/drug effects , Neurites/ultrastructure , Nocodazole/pharmacology , Paclitaxel/pharmacology , Phosphorylation , Plasmids/genetics , RNA, Small Interfering/pharmacology , Rats , Real-Time Polymerase Chain Reaction , Transfection , tau Proteins/genetics
14.
J Pineal Res ; 51(4): 426-33, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21797922

ABSTRACT

Recent studies suggest that oxidative stress and mitochondrial dysfunction play important roles in the neurotoxicity of nickel. Because mitochondrial DNA (mtDNA) is highly vulnerable to oxidative stress and melatonin can efficiently protect mtDNA against oxidative damage in various pathological conditions, the aims of this study were to determine whether mtDNA oxidative damage was involved in the neurotoxicity of nickel and to assay the neuroprotective effects of melatonin in mtDNA. In this study, we exposed mouse neuroblastoma cell lines (Neuro2a) to different concentrations of nickel chloride (NiCl(2), 0.125, 0.25, and 0.5 mm) for 24 hr. We found that nickel significantly increased reactive oxygen species (ROS) production and mitochondrial superoxide levels. In addition, nickel exposure increased mitochondrial 8-hydroxyguanine (8-OHdG) content and reduced mtDNA content and mtDNA transcript levels. Consistent with this finding, nickel was found to destroy mtDNA nucleoid structure and decrease protein levels of Tfam, a key protein component for nucleoid organization. However, all the oxidative damage to mtDNA induced by nickel was efficiently attenuated by melatonin pretreatment. Our results suggest that oxidative damage to mtDNA may account for the neurotoxicity of nickel. Melatonin has great pharmacological potential in protecting mtDNA against the adverse effects of nickel in the nervous system.


Subject(s)
DNA, Mitochondrial/drug effects , Melatonin/pharmacology , Nickel/toxicity , Oxidative Stress/drug effects , 8-Hydroxy-2'-Deoxyguanosine , Animals , Cell Line, Tumor , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/metabolism , Mice , Reactive Oxygen Species/metabolism , Superoxides/metabolism
15.
Toxicol Appl Pharmacol ; 253(1): 38-44, 2011 May 15.
Article in English | MEDLINE | ID: mdl-21419151

ABSTRACT

Mitochondrial dysfunction is thought to be a part of the mechanism underlying nickel-induced neurotoxicity. L-carnitine (LC), a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine in all mammalian species, manifests its neuroprotective effects by improving mitochondrial energetics and function. The purpose of this study was to investigate whether LC could efficiently protect against nickel-induced neurotoxicity. Here, we exposed a mouse neuroblastoma cell line (Neuro-2a) to different concentrations of nickel chloride (NiCl2) (0.25, 0.5, 1, and 2 mM) for 24 h, or to 0.5 mM and 1 mM NiCl2 for various periods (0, 3, 6, 12, or 24 h). We found that nickel significantly increased the cell viability loss and lactate dehydrogenase (LDH) release in Neuro-2a cells. In addition, nickel exposure significantly elevated reactive oxygen species (ROS) and malondialdehyde (MDA) levels, disrupted the mitochondrial membrane potential (ΔΨ(m)), reduced adenosine-5'-triphosphate (ATP) concentrations and decreased mitochondrial DNA (mtDNA) copy numbers and mtRNA transcript levels. However, all of the cytotoxicities and mitochondrial dysfunctions that were triggered by nickel were efficiently attenuated by pretreatment with LC. These protective effects of LC may be attributable to its role in maintaining mitochondrial function in nickel-treated cells. Our results suggest that LC may have great pharmacological potential in protecting against the adverse effects of nickel in the nervous system.


Subject(s)
Carnitine/pharmacology , Mitochondria/drug effects , Mitochondria/pathology , Nickel/toxicity , Animals , Cell Line, Tumor , Cell Survival/drug effects , Cell Survival/physiology , Dose-Response Relationship, Drug , Mice , Neurotoxicity Syndromes/metabolism , Neurotoxicity Syndromes/pathology , Neurotoxicity Syndromes/prevention & control , Nickel/antagonists & inhibitors , Reactive Oxygen Species/metabolism
16.
J Pineal Res ; 49(1): 86-94, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20536687

ABSTRACT

Nickel is a potential neurotoxic pollutant. Oxidative stress is supposed to be involved in the mechanism underlying nickel-induced neurotoxicity. Melatonin has efficient protective effects against various oxidative damages in nervous system. The purpose of this study was to investigate whether melatonin could efficiently protect against neurotoxicity induced by nickel. Here, we exposed primary cultured cortical neurons and mouse neuroblastoma cell lines (neuro2a) to different concentrations of nickel chloride (NiCl(2)) (0.125, 0.25, 0.5, and 1 mm) for 12 hr or 0.5 mm NiCl(2) for various periods (0, 3, 6, 12, and 24 hr). We found that nickel significantly increased reactive oxygen species production and caused the loss of cell viability both in cortical neurons and neuro2a cells. In addition, nickel exposure obviously inhibited the mitochondrial function, disrupted the mitochondrial membrane potential (DeltaPsim), reduced ATP production, and decreased mitochondrial DNA (mtDNA) content. However, each of these oxidative damages was efficiently attenuated by melatonin pretreatment. These protective effects of melatonin may be attributable to its roles in reducing oxidative stress and improving mitochondrial function in nickel-treated nerve cells. Our results suggested that melatonin may have great pharmacological potential in protecting against the adverse effects of nickel in the nervous system.


Subject(s)
Melatonin/pharmacology , Membrane Potential, Mitochondrial/drug effects , Nervous System Diseases/drug therapy , Neurons/drug effects , Nickel/toxicity , Oxidative Stress/drug effects , Adenosine Triphosphate/metabolism , Animals , Cell Line, Tumor , Cell Survival/drug effects , Cells, Cultured , DNA, Mitochondrial/drug effects , Electron Transport/drug effects , Flow Cytometry , Mice , Mice, Inbred BALB C , Microscopy, Confocal , Nervous System Diseases/chemically induced , Nervous System Diseases/metabolism , Nervous System Diseases/pathology , Neurons/metabolism , Reactive Oxygen Species/metabolism , Toxicity Tests
17.
Appl Microbiol Biotechnol ; 71(6): 927-34, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16307271

ABSTRACT

Microorganisms that bring about the aerobic transformation of imidacloprid (IMI) were isolated and screened, and the microbial regio- and stereoselective hydroxylation of IMI was studied. Some bacteria and fungi transformed IMI to 5-hydroxyl IMI. Bacterium Stenotrophomonas maltophilia CGMCC 1.1788 resting cells transformed IMI into R-5-hydroxyl IMI at the highest conversion rate. The enzyme catalyzed the stereoselective hydroxylation at position C12 of IMI in the imidazolidine ring. Under acidic conditions, 5-hydroxyl IMI was converted into olefin IMI in high molar conversion yield. The olefin IMI exhibited about 19 and 2.2 times more insecticidal efficacy than IMI against horsebean aphid imago and nymph, respectively, and about 1.4 times more active than IMI against brown planthopper imago. The transformation rate of IMI by resting cells of S. maltophilia CGMCC 1.1788 was promoted significantly by some carbohydrates and organic acids. The reaction medium with 5% sucrose resulted in 8.3 times greater biotransformation yield as compared with that without sucrose.


Subject(s)
Imidazoles/metabolism , Insecticides/metabolism , Bacteria/metabolism , Biotransformation , Fungi/metabolism , Hydrogen-Ion Concentration , Hydroxylation , Imidazoles/chemistry , Insecticides/chemistry , Molecular Structure , Neonicotinoids , Nitro Compounds , Oxidation-Reduction , Stereoisomerism , Temperature
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