Paradoxical Roles of Antioxidant Enzymes: Basic Mechanisms and Health Implications.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate "paradoxical" outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of "antioxidant" nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that "paradoxical" roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways.

Zinc Deficiency Exacerbates Behavioral Impediments and Dopaminergic Neuron Degeneration in a Mouse Model of Parkinson Disease.

BACKGROUND: Circulating zinc (Zn) concentrations are lower than normal in patients with Parkinson disease (PD). It is unknown whether Zn deficiency increases the susceptibility to PD. OBJECTIVES: The study aimed to investigate the effect of dietary Zn deficiency on behaviors and dopaminergic neurons in a mouse model of PD and to explore potential mechanisms. METHODS: Male C57BL/6J mice aged 8-10 wk were fed Zn adequate (ZnA; 30 µg/g) or Zn deficient (ZnD; <5 µg/g) diet throughout the experiments. Six weeks later 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was injected to generate the PD model. Controls were injected with saline. Thus, 4 groups (Saline-ZnA, Saline-ZnD, MPTP-ZnA, and MPTP-ZnD) were formed. The experiment lasted 13 wk. Open field test, rotarod test, immunohistochemistry, and RNA sequencing were performed. Data were analyzed with t-test, 2-factor ANOVA, or Kruskal-Wallis test. RESULTS: Both MPTP and ZnD diet treatments led to a significant reduction in blood Zn concentrations (PMPTP = 0.012, PZn = 0.014), reduced total distance traveled (PMPTP < 0.001, PZn = 0.031), and affected the degeneration of dopaminergic neurons in the substantia nigra (PMPTP < 0.001, PZn = 0.020). In the MPTP-treated mice, the ZnD diet significantly reduced total distance traveled by 22.4% (P = 0.026), decreased latency to fall by 49.9% (P = 0.026), and reduced dopaminergic neurons by 59.3% (P = 0.002) compared with the ZnA diet. RNA sequencing analysis revealed a total of 301 differentially expressed genes (156 upregulated; 145 downregulated) in the substantia nigra of ZnD mice compared with ZnA mice. The genes were involved in a number of processes, including protein degradation, mitochondria integrity, and α-synuclein aggregation. CONCLUSIONS: Zn deficiency aggravates movement disorders in PD mice. Our results support previous clinical observations and suggest that appropriate Zn supplementation may be beneficial for PD.

An antisense Alu transposon insertion/deletion polymorphism of ALDH1A1 may functionally associate with Parkinson's disease.

BACKGROUND: Aldehyde dehydrogenase 1 (encoded by ALDH1A1) has been shown to protect against Parkinson's disease (PD) by reducing toxic metabolites of dopamine. We herein revealed an antisense Alu element insertion/deletion polymorphism in intron 4 of ALDH1A1, and hypothesized that it might play a role in PD.  METHODS: A Han Chinese cohort comprising 488 PD patients and 515 controls was recruited to validate the Alu insertion/deletion polymorphism following a previous study of tag-single nucleotide polymorphisms, where rs7043217 was shown to be significantly associated with PD. Functional analyses of the Alu element insertion were performed. RESULTS: The Alu element of ALDH1A1 was identified to be a variant of Yb8 subfamily and termed as Yb8c4. The antisense Yb8c4 insertion/deletion polymorphism (named asYb8c4ins and asYb8c4del, respectively) appeared to be in a complete linkage disequilibrium with rs7043217 and was validated to be significantly associated with PD susceptibility with asYb8c4ins serving as a risk allele (P = 0.030, OR = 1.224, 95% CI = 1.020-1.470). Multiple functional analyses including ALDH1A1 mRNA expression in blood cells of carriers, and reporters of EGFP and luciferase showed that the asYb8c4ins had a suppressive activity on gene transcription. Mechanistic explorations suggested that the asYb8c4ins induced no changes in CpG methylation and mRNA splicing of ALDH1A1 and appeared no binding of transcription factors. CONCLUSIONS: Our results consolidate an involvement of ALDH1 in PD pathogenesis. The asYb8c4 polymorphism may be a functional output of its linkage disequilibrium-linked single nucleotide polymorphisms.

A signal-off photoelectrochemical aptasensor for ultrasensitive 17ß-estradiol detection based on rose-like CdS@C nanostructure and enzymatic amplification.

Carbon-coated cadmium sulfide rose-like nanostructures (CdS@C NRs) were prepared via a facile solvothermal approach and used as the photoelectrochemical (PEC) sensing platform for the integration of functional biomolecules. Based on this, a novel "signal-off" PEC aptasensor mediated by enzymatic amplification was proposed for the sensitive and selective detection of 17ß-estradiol (E2). In the presence of E2, alkaline phosphatase-modified aptamer (ALP-apta) were released from the electrode surface through the specific recognition with E2, which caused the negative effect on PEC response due to the decrease of ascorbic acid (AA) produced by the ALP in situ enzymatic catalysis. The developed PEC aptasensor for detection of E2 exhibited a wide linear range of 1.0-250 nM, with the low detection limit of 0.37 nM. This work provides novel insight into the design of potential phoelectroactive materials and the application of signal amplification strategy in environmental analysis field.

Differential and paradoxical roles of new-generation antidepressants in primary astrocytic inflammation.

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used new-generation drugs for depression. Depressive symptoms are thought to be closely related to neuroinflammation. In this study, we used up-to-date protocols of culture and stimulation and aimed to understand how astrocytes respond to the antidepressants. METHODS: Primary astrocytes were isolated and cultured using neurobasal-based serum-free medium. The cells were treated with a cytokine mixture comprising complement component 1q, tumor necrosis factor α, and interleukin 1α with or without pretreatments of antidepressants. Cell viability, phenotypes, inflammatory responses, and the underlying mechanisms were analyzed. RESULTS: All the SSRIs, including paroxetine, fluoxetine, sertraline, citalopram, and fluvoxamine, show a visible cytotoxicity within the range of applied doses, and a paradoxical effect on astrocytic inflammatory responses as manifested by the promotion of inducible nitric oxide synthase (iNOS) and/or nitric oxide (NO) and the inhibition of interleukin 6 (IL-6) and/or interleukin 1ß (IL-1ß). The SNRI venlafaxine was the least toxic to astrocytes and inhibited the production of IL-6 and IL-1ß but with no impact on iNOS and NO. All the drugs had no regulation on the polarization of astrocytic A1 and A2 types. Mechanisms associated with the antidepressants in astrocytic inflammation route via inhibition of JNK1 activation and STAT3 basal activity. CONCLUSIONS: The study demonstrated that the antidepressants possess differential cytotoxicity to astrocytes and function differently, also paradoxically for the SSRIs, to astrocytic inflammation. Our results provide novel pieces into understanding the differential efficacy and tolerability of the antidepressants in treating patients in the context of astrocytes.

Paroxetine suppresses reactive microglia-mediated but not lipopolysaccharide-induced inflammatory responses in primary astrocytes.

BACKGROUND: Astrocytes are the most abundant glial cells in a brain that mediate inflammatory responses and provide trophic support for neurons. We have previously disclosed that paroxetine, a common selective serotonin reuptake inhibitor, ameliorates LPS-induced microglia activation. However, it remains elusive for the role of paroxetine in astrocytic responses. METHODS: Isolated primary astrocytes were pretreated with paroxetine and stimulated with different stimuli, lipopolysaccharide (LPS) or microglia conditioned medium pre-activated with LPS (M/Lps). Inflammatory and neurotrophic responses, underlying mechanisms and the impact on neuronal survival were assessed. RESULTS: Paroxetine had no impact on LPS-stimulated iNOS, TNF-α, and IL-1ß expression, but inhibited M/Lps-induced TNF-α and IL-1ß expression in primary astrocytes. Paroxetine suppressed M/Lps- but not LPS-induced activation of NF-κB and had no impact on the activation of MAPKs and STAT3. Incubation with the resulted astrocyte conditioned media caused no change in the viability of SH-SY5Y cells. BDNF and MANF mRNA expressions were upregulated by M/Lps and paroxetine, respectively. However, M/Lps- or LPS-induced extracellular releases of NO, TNF-α, and/or BDNF in astrocytes were in minor amount compared to those by microglia. CONCLUSIONS: Paroxetine ameliorates the reactive microglia-mediated inflammatory responses in astrocytes partially via inhibition of the NF-κB pathway but has no impact on LPS-stimulated astrocyte activation. While the effects of paroxetine on secondary astrocytic responses are not robust compared to its effect on the innate immune responses of microglia, the results together may implicate a therapeutic potential of paroxetine against neuroinflammation-associated neurological disorders such as Parkinson's disease.

Selenoprotein T Promotes Proliferation and G1-to-S Transition in SK-N-SH Cells: Implications in Parkinson's Disease.

BACKGROUND: Selenium is prioritized to the brain mainly for selenoprotein expression. Selenoprotein T (SELENOT) protects dopaminergic, postmitotic neurons in a mouse model of Parkinson's disease (PD). OBJECTIVE: We hypothesized a proliferative role of SELENOT in neural cells. METHODS: To assess SELENOT status in PD, sedated male C57BL/6 mice at 10-12 wk of age were injected with 6-hydroxydopamine in neurons, and human peripheral blood mononuclear cells were isolated from 9 healthy subjects (56% men, 68-y-old) and 11 subjects with PD (64% men, 63-y-old). Dopaminergic neural progenitor-like SK-N-SH cells with transient SELENOT overexpression or knockdown were maintained in the presence or absence of the antioxidant N-acetyl-l-cysteine and the calcium channel blocker nimodipine. Cell cycle, proliferation, and signaling parameters were determined by immunoblotting, qPCR, and flow cytometry. RESULTS: SELENOT mRNA abundance was increased (P < 0.05) in SK-N-SH cells treated with 1-methyl-4-phenylpyridinium iodide (3.5-fold) and peripheral blood mononuclear cells from PD patients (1.6-fold). Likewise, SELENOT was expressed in tyrosine hydroxylase-positive dopaminergic neurons of 6-hydroxydopamine-injected mice. Knockdown of SELENOT in SK-N-SH cells suppressed (54%; P < 0.05) 5-ethynyl-2'-deoxyuridine incorporation but induced (17-47%; P < 0.05) annexin V-positive cells, CASPASE-3 cleavage, and G1/S cell cycle arrest. SELENOT knockdown and overexpression increased (88-120%; P < 0.05) and reduced (37-42%; P < 0.05) both forkhead box O3 and p27, but reduced (51%; P < 0.05) and increased (1.2-fold; P < 0.05) cyclin-dependent kinase 4 protein abundance, respectively. These protein changes were diminished by nimodipine or N-acetyl-l-cysteine treatment (24 h) at steady-state levels. While the N-acetyl-l-cysteine treatment did not influence the reduction in the amount of calcium (13%; P < 0.05) by SELENOT knockdown, the nimodipine treatment reversed the decreased amount of reactive oxygen species (33%; P < 0.05) by SELENOT overexpression. CONCLUSIONS: These cellular and mouse data link SELENOT to neural proliferation, expanding our understanding of selenium protection in PD.

Mitochondrial DNA variants modulate genetic susceptibility to Parkinson's disease in Han Chinese.

It is well recognized that mitochondrial dysfunction is involved in the pathogenesis of Parkinson's disease (PD). The mtDNA displacement loop (D-loop) region is known to accumulate structural alterations and mutations. To understand how mtDNA variants contribute to the susceptibility to sporadic PD in Chinese, a total of 500 PD patients and 505 controls were recruited from East China, and their D-loop regions were sequenced. A total of 389 variants were detected out of the 1005 subjects. There were 91 variants with frequencies >1%, which included 88 single nucleotide polymorphisms (SNPs), 2 deletions and 1 insertion. Amongst, 6 SNPs were significantly associated with sporadic PD. Specifically, the SNPs 151T/C, 189G/A, 16086C/T and 16271C/T contributed to increased susceptibility, while 318C/T and 16134T/C were associated with reduced risk for PD. Further analyses of mtDNA haplogroups and their risk for PD occurrence showed that subjects carrying haplogroup A5 were susceptible while haplogroup B5 carriers were more resistant to the disease. In summary, our study for the first time systematically analyzed mtDNA variants by sequencing the D-loop region in a Chinese population to understand their associations with PD. These results demonstrate that mtDNA variants modulate risk for sporadic PD.

Nuclear selenoproteins and genome maintenance.

Selenium is an essential metalloid required for the expression of selenoproteins. While cells are constantly challenged by clastogens of endogenous and exogenous origins, genome integrity is maintained by direct repair of DNA damage, redox balance, and epigenetic regulation. To date, only five selenoproteins are experimentally demonstrated to reside in nucleus, exclusively or partially, including selenoprotein H, methionine-R-sulfoxide reductase 1, glutathione peroxidase-4, thioredoxin reductase-1, and thioredoxin glutathione reductase. All these five selenoproteins have demonstrated or potential roles in redox regulation and genome maintenance. Selenoprotein H is known to transactivate the expression of a couple of genes against oxidative stress. The thioredoxin reductase-1b isoform delivers estrogen receptor-α and -ß to the nucleus. Nuclear glutathione peroxidase-4 epigenetically and globally inhibits gene expression through the maintenance of chromatin compactness in testes. Continued studies on how these and additional nuclear selenoproteins regulate genome stability will have profound impact on advancing our understanding in selenium regulation of optimal health. © 2015 IUBMB Life, 68(1):5-12, 2016.

[Effect of Shouwu Shudi Yin on dopaminegic neurons in MPTP induced Parkinson's disease mouse model].

In order to investigate the effect of Shouwu Shudi Yin on dopaminegic neurons in MPTP induced Parkinson's disease mouse model and the possible mechamism, the experimental mice were randomly divided into 4 groups: control, Shouwu Shudi Yin, MPTP and the treatment (MPTP+Shouwu Shudi Yin) groups. The number of tyrosine hydroxylase (TH) positive cells in the substantia nigra was measured by immunohistochemistry, and mRNA expression of TH and glutathione peroxidase (GPX) were detected by PCR. The results showed that the number of TH positive cells and mRNA expression of TH were significantly reduced in MPTP group compared with the control (P<0.05), and pretreated with Shouwu Shudi Yin didn't show protective effect. Compared to MPTP group, the mRNA expression of four subtypes of GPX were increased in various degrees in the treatment group pretreated with Shouwu Shudi Yin, although the difference was not statistically significant. These indicated that the preventive medication of Shouwu Shudi Yin don't have protective effect on the mice with Parkinson' s disease induced by MPTP, but it may enhance the antioxidant capacity through increasing the expression of GPX.

Paroxetine ameliorates lipopolysaccharide-induced microglia activation via differential regulation of MAPK signaling.

BACKGROUND: Paroxetine, a selective serotonin reuptake inhibitor for counteracting depression, has been recently suggested as having a role in prevention of dopaminergic neuronal degeneration in substantia nigra, a hallmark of Parkinson's disease (PD). The pathogenesis of this type of neurological disorders often involves the activation of microglia and associated inflammatory processes. Thus in this study we aimed to understand the role of paroxetine in microglia activation and to elucidate the underlying mechanism(s). METHODS: BV2 and primary microglial cells were pretreated with paroxetine and stimulated with lipopolysaccharide (LPS). Cells were assessed for the responses of pro-inflammatory mediator and cytokines, and the related signaling pathways were evaluated and analyzed in BV2 cells. RESULTS: Paroxetine significantly inhibited LPS-induced production of nitric oxide (NO) and pro-inflammatory cytokines such as TNF-α and IL-1ß. Further analysis showed inducible nitric oxide synthase (iNOS) and mRNA expression of TNF-α and IL-1ß were attenuated by paroxetine pretreatment. Analyses in signaling pathways demonstrated that paroxetine led to suppression of LPS-induced JNK1/2 activation and baseline ERK1/2 activity, but had little effect on the activation of p38 and p65/NF-κB. Interference with specific inhibitors revealed that paroxetine-mediated suppression of NO production was via JNK1/2 pathway while the cytokine suppression was via both JNK1/2 and ERK1/2 pathways. Furthermore, conditioned media culture showed that paroxetine suppressed the microglia-mediated neurotoxicity. CONCLUSIONS: Paroxetine inhibits LPS-stimulated microglia activation through collective regulation of JNK1/2 and ERK1/2 signaling. Our results indicate a potential role of paroxetine in neuroprotection via its anti-neuroinflammatory effect besides targeting for depression.

Early release of high-mobility group box 1 (HMGB1) from neurons in experimental subarachnoid hemorrhage in vivo and in vitro.

BACKGROUND: Translocation of high-mobility group box 1 (HMGB1) from nucleus could trigger inflammation. Extracellular HMGB1 up-regulates inflammatory response in sepsis as a late mediator. However, little was known about its role in subarachnoid hemorrhage-inducible inflammation, especially in the early stage. This study aims to identify whether HMGB1 translocation occurred early after SAH and also to clarify the potential role of HMGB1 in brain injury following SAH. METHODS: Sprague-Dawley (SD) rats were randomly divided into sham group and SAH groups at 2 h, 12 h and on day 1, day 2. SAH groups suffered experimental subarachnoid hemorrhage by injection of 0.3 ml autoblood into the pre-chiasmatic cistern. Rats injected by recombinant HMGB1(rHMGB1) solution were divided into four groups according to different time points. Cultured neurons were assigned into control group and four hemoglobin (Hb) incubated groups. Mixed glial cells were cultured and stimulated in medium from neurons incubated by Hb. HMGB1 expression is measured by western blot analysis, real-time polymerase chain reaction (PCR), immunohistochemistry and immunofluorescence. Downstream nuclear factor kappa B (NF-κB) subunit P65 and inflammatory factor Interleukin 1ß (IL-1ß) were measured by western blot and real-time PCR, respectively. Brain injury was evaluated by cleaved caspase-3 staining. RESULTS: Our results demonstrated HMGB1 translocation occurred as early as 2 h after experimental SAH with mRNA and protein level increased. Immunohistochemistry and immunofluorescence results indicated cytosolic HMGB1 was mainly located in neurons while translocated HMGB1 could also be found in some microglia. After subarachnoid injection of rHMGB1, NF-κB, downstream inflammatory response and cleaved caspase-3 were up-regulated in the cortex compared to the saline control group. In-vitro, after Hb incubation, HMGB1 was also rapidly released from neurons to medium. Incubation with medium from neurons up-regulated IL-1ß in mixed glial cells. This effect could be inhibited by HMGB1 specific inhibitor glycyrrhizic acid (GA) treatment. CONCLUSION: HMGB1 was released from neurons early after SAH onset and might trigger inflammation as an upstream inflammatory mediator. Extracellular HMGB1 contributed to the brain injury after SAH. These results might have important implications during the administration of specific HMGB1 antagonists early in order to prevent or reduce inflammatory response following SAH.

Growth inhibitory in vitro effects of glycyrrhizic acid in U251 glioblastoma cell line.

Despite dramatic advances in cancer therapy, the overall prognosis of glioblastoma (GBM) remains dismal. Nuclear factor kappa-B (NF-κB) has been previously demonstrated to be constitutively activated in glioblastoma, and it was suggested as a potential therapeutic target. Glycyrrhizic acid (GA) has been proved to have cytotoxic effects in many cancer cell lines. However, its role in glioblastoma has not yet been addressed. Therefore, this study aimed to investigate the effects of GA on human glioblastoma U251 cell line. The effects of GA on proliferation of U251 cells were measured by CCK-8 assay and plate colony-forming test. Cellular apoptosis was detected by Hoechst 33258 fluorescent staining and flow cytometry with annexin V-FITC/PI dual staining. The expression of nuclear p65 protein, the active subunit of NF-κB, was determined by Western blot and immunofluorescence. Our results demonstrated that the survival rate and colony formation of U251 cells significantly decreased in a time- and dose-dependent manner after GA addition, and the apoptotic ratio of GA-treated groups was significantly higher than that of control groups. Furthermore, the expression of NF-κB-p65 in the nucleus was remarkably reduced after GA treatment. In conclusion, our findings suggest that GA treatment can confer inhibitory effects on human glioblastoma U251 cell line including inhibiting proliferation and inducing apoptosis, which is possibly related to the NF-κB mediated pathway.

CCDC62 variant rs12817488 is associated with the risk of Parkinson's disease in a Han Chinese population.

It has been recently proposed by a genome-wide association study (GWAS) meta-analysis that the CCDC62 variant rs12817488 is a new risk locus associated with Parkinson's disease (PD). In this study, we aimed to investigate the association between rs12817488 and PD in a Chinese cohort. A total of 341 PD patients and 423 matched controls were recruited in Eastern China. Our results showed that the A allele of rs12817488 was significantly associated with an aggravated risk of PD (p = 0.006) and represented a major allele in contrast to a minor one in Caucasians. Genotype distributions also differed between PD patients and controls (p = 0.011 for AA/AG/GG). Further analysis showed that the association of rs12817488 with PD only existed in females. We also investigated the protein level of CCDC62 in peripheral blood mononuclear cells from 41 AA or GG carriers and found an apparently higher expression in PD patients carrying the AA genotype. A potential interaction was found between two estrogen-related loci, i.e. rs12817488/CCDC62 and rs2697962/PRDM2, particularly in the female stratum. In conclusion, our study demonstrated for the first time a significant association between the rs12817488 polymorphism and PD predisposition in a Chinese population with gender variations and provides new insight regarding the variant's protein expression and estrogen-related genetic interaction.

Homochiral light-sensitive metal-organic framework photoelectrochemical gated transistor for enantioselective discrimination of monosaccharides.

As pure antipodes may differ in biological interactions, pharmacology, and toxicity, discrimination of enantiomers is important in the pharmaceutical and agrochemical industries. Two major challenges in enantiomer determination are transducing and amplifying the distinct chiral-recognition signals. In this study, a light-sensitive organic photoelectrochemical transistor (OPECT) with homochiral character is developed for enantiomer discrimination. Demonstrated with the discrimination of glucose enantiomers, the photoelectrochemically active gate electrode is prepared by integrating Au nanoparticles (AuNPs) and a chiral Cu(II)-metal-organic framework (c-CuMOF) onto TiO2 nanotube arrays (TNT). The captured glucose enantiomers are oxidized to hydrogen peroxide (H2O2) by the oxidase-mimicking AuNPs-loaded c-CuMOF. Based on the confinement effect of the mesopocket structure of the c-CuMOF and the remarkable charge transfer ability of the 1D nanotubular architecture, variations in H2O2 yield are translated into significant changes in OPECT drain currents (ID) by inducing a catalytic precipitation reaction. Variations in ID confer a sensitive discrimination of glucose enantiomers with a limit of detection (LOD) of 0.07 µM for L-Glu and 0.05 µM for D-Glu. This enantiomer-driven gate electrode response strategy not only provides a new route for enantiomer identification, but also helps to understand the origin of the high stereoselectivity in living systems.

Association analyses of apolipoprotein E genotypes and cognitive performance in patients with Parkinson's disease.

BACKGROUND: Cognitive impairment is a common non-motor symptom of Parkinson's disease (PD). The apolipoprotein E (APOE) ε4 genotype increases the risk of Alzheimer's disease (AD). However, the effect of APOEε4 on cognitive function of PD patients remains unclear. In this study, we aimed to understand whether and how carrying APOEε4 affects cognitive performance in patients with early-stage and advanced PD. METHODS: A total of 119 Chinese early-stage PD patients were recruited. Movement Disorder Society Unified Parkinson's Disease Rating Scale, Hamilton anxiety scale, Hamilton depression scale, non-motor symptoms scale, Mini-mental State Examination, Montreal Cognitive Assessment, and Fazekas scale were evaluated. APOE genotypes were determined by polymerase chain reactions and direct sequencing. Demographic and clinical information of 521 early-stage and 262 advanced PD patients were obtained from Parkinson's Progression Marker Initiative (PPMI). RESULTS: No significant difference in cognitive performance was found between ApoEε4 carriers and non-carriers in early-stage PD patients from our cohort and PPMI. The cerebrospinal fluid (CSF) Amyloid Beta 42 (Aß42) level was significantly lower in ApoEε4 carrier than non-carriers in early-stage PD patients from PPMI. In advanced PD patients from PPMI, the BJLOT, HVLT retention and SDMT scores seem to be lower in ApoEε4 carriers without reach the statistical significance. CONCLUSIONS: APOEε4 carriage does not affect the cognitive performance of early-stage PD patients. However, it may promote the decline of CSF Aß42 level and the associated amyloidopathy, which is likely to further contribute to the cognitive dysfunction of PD patients in the advanced stage.

Evaluation of early precut with needle-knife in difficult biliary cannulation during ERCP.

BACKGROUND: There is scarce information on whether performing the precut procedure early rather than after several cannulation attempts is associated with different success and complication rates. OBJECTIVE: The aim of this retrospective study was is to compare the early precut technique with the standard one in terms of the results and complications. METHODS: The contemporary success rate and postoperative complications in 792 endoscopic retrograde cholangiopancreatography cases were frequently observed during the period from June 2007 to May 2011, and 56 of these cases were carried out with precut biliary sphincterotomy after the standard sphincterotomy had failed. RESULTS: The success rate for standard sphincterotomy was 89.8%: 51 out of 56 cases were carried out with precut biliary sphincterotomy and succeeded. The total success rate was 96.3%. The difference was significant (χ2=25.62, p<0.01) compared to the success rate of first cannulation, while the difference in complication rates between precut and standard sphincterotomy was minor (9.9 vs. 12.5%, p>0.05). CONCLUSION: Early precut with a needle-knife in a difficult biliary cannulation was safe and effective if performed by experienced endoscopists.

Increase of cyclooxygenase-2 inhibition with celecoxib combined with 5-FU enhances tumor cell apoptosis and antitumor efficacy in a subcutaneous implantation tumor model of human colon cancer.

BACKGROUND: The purpose of this study was to investigate the anti-tumor effect and explore the mechanisms of celecoxib (a selective cyclooxygenase-2 inhibitor) combined with 5-fluorouracil (5-FU) on the treatment of human colorectal cancer in a BALB/C nude mouse subcutaneous xenograft model. METHODS: Effects of celecoxib combined with 5-FU on the proliferation of xenograft carcinoma induced by HT-29 were investigated. The apoptotic cells were detected by electron microscope and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. Immunohistochemistry and Western blot were used to estimate the expression of cytochrome C, caspase-3 and caspase-9. RESULTS: Compared with the control group, treatment groups showed significant inhibition of tumor growth. More apoptotic cells existed after treatment with celecoxib combined with 5-FU. Cytochrome C, caspase-3 and caspase-9 were increased in treated groups, and more obviously in the drug combination group. Cyclooxygenase-2 (COX-2) were decreased after treatment with celecoxib only or combined with 5-FU. And the combined group showed a greater decrease. CONCLUSIONS: Celecoxib combined with 5-FU could inhibit the growth of tumors in vivo by inducing apoptosis and activation of the cytochrome C dependency apoptosis signal pathway. A decrease of COX-2 and an increase of cytochrome C, caspase-3 and caspase-9 may be involved in this process.

[Two-dimensional gel electrophoresis map of serum proteins in patients with chronic Keshan disease].

OBJECTIVE: To identify the different serum proteins expressed in patients with Keshan disease (KD). METHODS: Two-dimensional gel electrophoresis (2-DE) was performed with serum samples from the patients with chronic KD and healthy controls to separate serum proteins. The gels were stained by sliver and scanned by Umax scanner. The data were analyzed by ImageMaster 2D software. KD related proteins were identified through searching the ExPASy SWISS-2DPAGE database. RESULTS: Stable two-dimensional gel electrophoresis maps were established for serum samples of KD patients and healthy controls. A total of 808 and 814 protein spots were observed in KD patients and healthy controls, respectively. The two maps had 96.5475% identical protein spots and 44 differentially expressed protein spots. Eleven protein spots were expressed exclusively in KD patients and 12 protein spots only appeared in healthy controls. About 21 proteins were expressed in both groups but varied in quantities (14 proteins were over-expressed by more than 3 times and 7 proteins were under-expressed by more than 3 times in KD patients, P < 0.01). Among the 353 protein spots matched with the ExPASy-SWISS-2DPAGE databank, No. 1177 protein appeared in the KD patient was found to have the closest match with P02774 2-D0004T6 known as vitamin D binding protein (VDBP). CONCLUSION: There is a significant difference in serum protein expression between KD patients and normal people. VDBP might play a role in cardiac muscle damage via inflammatory immune reactions.

Integration of phosphate functionalized Pt/TiO2 and Ru(bpy)32+ sensitization for ultrasensitive assay of adenosine deaminase activity on a novel split-typed PEC aptasensor.

To date, it is still a challenge for high-performance photoelectrochemical (PEC) assay of low-abundance adenosine deaminase (ADA) in fundamental research and clinical diagnosis. Herein, phosphate-functionalized Pt/TiO2 (termed PO43-/Pt/TiO2) was prepared as ideal photoactive material to develop a split-typed PEC aptasensor for detection of ADA activity, coupled by a Ru(bpy)32+ sensitization strategy. We critically studied the effects of the PO43- and Ru(bpy)32+ on the detection signals, and discussed the signal-amplified mechanism. Specifically, hairpin-structured adenosine (AD) aptamer was splited into single chain via ADA-induced catalytic reaction, and subsequently hybridized with complementary DNA (cDNA, initially coating on magnetic beads). The in-situ formed double-stranded DNA (dsDNA) was further intercalated by more Ru(bpy)32+ to amplify the photocurrents. The resultant PEC biosensor showed a broader linear range of 0.05-100 U L-1 and a lower limit of detection (0.019 U L-1), which can fill the blank for analysis of ADA activity. This research would provide some valuable insights for building advanced PEC aptasensors in ADA-related research and clinical diagnosis.