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1.
Health Qual Life Outcomes ; 20(1): 80, 2022 May 19.
Article in English | MEDLINE | ID: mdl-35590333

ABSTRACT

OBJECTIVE: Two EQ-5D-3L (3L) value sets (developed in 2014 and 2018) co-exist in China. The study examined the level of agreement between index scores for all the 243 health states derived from them at both absolute and relative levels and compared the responsiveness of the two indices. METHODS: Intraclass correlations coefficient (ICC) and Bland-Altman plot were adopted to assess the degree of agreement between the two indices at the absolute level. Health gains for 29,403 possible transitions between pairs of 3L health states were calculated to assess the agreement at the relative level. Their responsiveness for the transitions was assessed using Cohen effect size. RESULTS: The mean (SD) value was 0.427 (0.206) and 0.649 (0.189) for the 3L2014 and 3L2018 index scores, respectively. Although the ICC value showed good agreement (i.e., 0.896), 88.9% (216/243) of the points were beyond the minimum important difference limit according to the Bland-Altman plot. The mean health gains for the 29,403 health transitions was 0.234 (3L2014 index score) and 0.216 (3L2018 index score). The two indices predicted consistent transitions in 23,720 (80.7%) of 29,403 pairs. For the consistent pairs, Cohen effective size value was 1.05 (3L2014 index score) or 1.06 (3L2018 index score); and the 3L2014 index score only yielded 0.007 more utility gains. However, the results based on the two measures varied substantially according to the direction and magnitude of health change. CONCLUSION: The 3L2014 and 3L2018 index scores are not interchangeable. The choice between them is likely to influence QALYs estimations.


Subject(s)
Health Status , Quality of Life , China , Humans , Psychometrics , Quality-Adjusted Life Years , Surveys and Questionnaires
2.
Biochim Biophys Acta Mol Basis Dis ; 1867(1): 165982, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33002579

ABSTRACT

Altered redox biology and oxidative stress have been implicated in the progression of heart failure. Glutaredoxin-2 (GRX2) is a glutathione-dependent oxidoreductase and catalyzes the reversible deglutathionylation of mitochondrial proteins. Sirtuin-3 (SIRT3) is a class III histone deacetylase and regulates lysine acetylation in mitochondria. Both GRX2 and SIRT3 are considered as key in the protection against oxidative damage in the myocardium. Knockout of either contributes to adverse heart pathologies including hypertrophy, hypertension, and cardiac dysfunction. Here, we created and characterized a GRX2 and SIRT3 double-knockout mouse model, hypothesizing that their deletions would have an additive effect on oxidative stress, and exacerbate mitochondrial function and myocardial structural remodeling. Wildtype, single-gene knockout (Sirt3-/-, Grx2-/-), and double-knockout mice (Grx2-/-/Sirt3-/-) were compared in heart weight, histology, mitochondrial respiration and H2O2 production. Overall, the hearts from Grx2-/-/Sirt3-/- mice displayed increased fibrosis and hypertrophy versus wildtype. In the Grx2-/- and the Sirt3-/- we observed changes in mitochondrial oxidative capacity, however this was associated with elevated H2O2 emission only in the Sirt3-/-. Similar changes were observed but not worsened in hearts from Grx2-/-/Sirt3-/- mice, suggesting that these changes were not additive. In human myocardium, using genetic and histopathological data from the human Genotype-Tissue Expression consortium, we confirmed that SIRT3 expression correlates inversely with heart pathology. Altogether, GRX2 and SIRT3 are important in the control of cardiac mitochondrial redox and oxidative processes, but their combined absence does not exacerbate effects, consistent with the overall conclusion that they function together in the complex redox and antioxidant systems in the heart.


Subject(s)
Energy Metabolism , Glutaredoxins/deficiency , Heart Failure/metabolism , Hydrogen Peroxide/metabolism , Mitochondria, Heart/metabolism , Myocardium/metabolism , Sirtuin 3/deficiency , Animals , Heart Failure/genetics , Heart Failure/pathology , Mice , Mice, Knockout , Mitochondria, Heart/pathology , Myocardium/pathology
3.
Front Genet ; 11: 562855, 2020.
Article in English | MEDLINE | ID: mdl-33240316

ABSTRACT

Wandong (WD) cattle has recently been identified as a new Chinese native cattle breed by the National Commission for Livestock and Poultry Genetic Resources. The population size of this breed is less than 10,000. WD cattle and Dabieshan (DB) cattle are sympatric but are raised in different ecological environments, on mountains and plains, respectively, and the body sizes of these two breeds are markedly different. Blood samples were obtained from 8 adult female WD cattle and 7 adult female DB cattle (24 months old). The total RNA was extracted from leukocyte cells, and sequencing experiments were conducted on the Illumina HiSeqTM 4000 platform. After the removal of one outlier sample from the WD cattle breed as determined by principal component analysis (PCA), phylogenetic and population structure analyses indicated that WD and DB cattle formed a distinct Central China cattle group and showed evidence of hybridization between Bos. taurus and Bos. indicus. The immune-regulator CD48 (P = 1.3E-6) was associated with breed-specific traits according to loss-of-function variant enrichment analysis. In addition, 113 differentially expressed genes were identified between the two breeds, many of which are associated with the regulation of body growth, which is the major difference between the two breeds. This study showed that WD cattle belong to the group of hybrids between Bos. Taurus and Bos. indicus, and one novel gene associated with breed traits and multiple differentially expressed genes between these two closely related breeds was identified. The results provide insights into the genetic mechanisms that underlie economically important traits, such as body size, in cattle.

4.
Anim Reprod Sci ; 218: 106506, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32507252

ABSTRACT

Activity of transcription factors affect synthesis of G-protein coupled receptor 54 (GPR54), an important factor in regulation of initiation of puberty. Expression of the GPR54 gene in cattle is associated with polymorphisms in the proximal regulatory region (PRR) of the GPR54 gene. Transcription resulting in production of GPR54 mRNA transcript occurs as a result of transcription factor (TF) interactions in the PRR. Polymorphisms in the PRR may be associated with extent of activity of these TFs. Folliculogenesis-specific BHLH TF (FIGLA), neurogenin 2 (NEUROG2), and early growth response 1 (EGR1) are important in modulation of ovarian follicle development and neurons synthesizing GnRH, thus, regulating biosynthesis of luteinizing hormone. The aim of this study, therefore, was to assess the transcription-activating potential of binding sites for FIGLA, NEUROG2, and EGR1 TFs in the GPR54 promoter of cattle. Two luciferase-based promoters, ATC and CCT, which contain three single nucleotide polymorphisms (SNPs), A/C-794, T/C-663, and C/T-601, in the GPR54 PRR, were analyzed to evaluate gene expression and activation of different promoters by FIGLA, NEUROG2, and EGR1. The FIGLA induced GPR54 transcription through the CCT, whereas NEUROG2 and EGR1 induced GPR54 transcription through the ATC promoter-binding site. The CCT-activating effects of FIGLA were greater (2.56-fold) than the ATC-activating effects (P < 0.05). The ATC-activating effects of NEUROG2 and EGR1 were markedly greater (12.91- and 8.41-fold; P < 0.01) than CCT-activating effects. The polymorphisms, CCT and ATC, of the cattle GPR54 affect the activity of transcription factors, therefore, have an important effect on production of GPR54 mRNA transcript.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Cattle/physiology , Early Growth Response Protein 1/metabolism , Nerve Tissue Proteins/metabolism , Polymorphism, Single Nucleotide , Receptors, Kisspeptin-1/metabolism , Animals , Base Sequence , Basic Helix-Loop-Helix Transcription Factors/genetics , Cattle/genetics , Early Growth Response Protein 1/genetics , Gene Expression Regulation , Nerve Tissue Proteins/genetics , Receptors, Kisspeptin-1/genetics , Regulatory Sequences, Nucleic Acid
5.
World J Hepatol ; 11(5): 421-441, 2019 May 27.
Article in English | MEDLINE | ID: mdl-31183003

ABSTRACT

About 10 million people in China are infected with hepatitis C virus (HCV), with the seroprevalence of anti-HCV in the general population estimated at 0.6%. Delaying effective treatment of chronic hepatitis C (CHC) is associated with liver disease progression, cirrhosis, hepatocellular carcinoma, and liver-related mortality. The extrahepatic manifestations of CHC further add to the disease burden of patients. Managing CHC-related advanced liver diseases and systemic manifestations are costly for both the healthcare system and society. Loss of work productivity due to reduced well-being and quality of life in CHC patients further compounds the economic burden of the disease. Traditionally, pegylated-interferon plus ribavirin (PR) was the standard of care. However, a substantial number of patients are ineligible for PR treatment, and only 40%-75% achieved sustained virologic response. Furthermore, PR is associated with impairment of patient-reported outcomes (PROs), high rates of adverse events, and poor adherence. With the advent of direct acting antivirals (DAAs), the treatment of CHC patients has been revolutionized. DAAs have broader eligible patient populations, higher efficacy, better PRO profiles, fewer adverse events, and better adherence rates, thereby making it possible to cure a large proportion of all CHC patients. This article aims to provide a comprehensive evaluation on the value of effective, curative hepatitis C treatment from the clinical, economic, societal, and patient experience perspectives, with a focus on recent data from China, supplemented with other Asian and international experiences where China data are not available.

6.
Mol Metab ; 25: 35-49, 2019 07.
Article in English | MEDLINE | ID: mdl-31060926

ABSTRACT

OBJECTIVE: Brown adipose tissue (BAT) is important for thermoregulation in many mammals. Uncoupling protein 1 (UCP1) is the critical regulator of thermogenesis in BAT. Here we aimed to investigate the deacetylation control of BAT and to investigate a possible functional connection between UCP1 and sirtuin 3 (SIRT3), the master mitochondrial lysine deacetylase. METHODS: We carried out physiological, molecular, and proteomic analyses of BAT from wild-type and Sirt3KO mice when BAT is activated. Mice were either cold exposed for 2 days or were injected with the ß3-adrenergic agonist, CL316,243 (1 mg/kg; i.p.). Mutagenesis studies were conducted in a cellular model to assess the impact of acetylation lysine sites on UCP1 function. Cardiac punctures were collected for proteomic analysis of blood acylcarnitines. Isolated mitochondria were used for functional analysis of OXPHOS proteins. RESULTS: Our findings showed that SIRT3 absence in mice resulted in impaired BAT lipid use, whole body thermoregulation, and respiration in BAT mitochondria, without affecting UCP1 expression. Acetylome profiling of BAT mitochondria revealed that SIRT3 regulates acetylation status of many BAT mitochondrial proteins including UCP1 and crucial upstream proteins. Mutagenesis work in cells suggested that UCP1 activity was independent of direct SIRT3-regulated lysine acetylation. However, SIRT3 impacted BAT mitochondrial proteins activities of acylcarnitine metabolism and specific electron transport chain complexes, CI and CII. CONCLUSIONS: Our data highlight that SIRT3 likely controls BAT thermogenesis indirectly by targeting pathways upstream of UCP1.


Subject(s)
Adipose Tissue, Brown/metabolism , Sirtuin 3/metabolism , Uncoupling Protein 1/metabolism , 3-Hydroxyacyl CoA Dehydrogenases , Acetyl-CoA C-Acyltransferase , Acetylation , Adipose Tissue, Brown/pathology , Adrenergic beta-3 Receptor Antagonists/adverse effects , Animals , Body Composition , Body Temperature Regulation , Carbon-Carbon Double Bond Isomerases , Carnitine/analogs & derivatives , Carnitine/pharmacology , Enoyl-CoA Hydratase , HEK293 Cells , Humans , Male , Mice , Mice, Knockout , Mitochondria/metabolism , Mitochondrial Proteins/metabolism , Models, Animal , Mutagenesis , Oxidative Phosphorylation , Proteomics , Racemases and Epimerases , Sirtuin 3/genetics , Thermogenesis/physiology
7.
Clin Ther ; 41(1): 78-91, 2019 01.
Article in English | MEDLINE | ID: mdl-30559005

ABSTRACT

PURPOSE: The aim of this study was to evaluate the cost-effectiveness of radiofrequency catheter ablation (RFCA) compared with cryoballoon (CB) ablation in the treatment of patients with paroxysmal atrial fibrillation (PAF) from the payer's perspective in China. METHODS: We constructed a cohort model, combining a 12-month decision-tree model with a lifetime Markov state-transition model, in a hypothetical cohort of patients with drug-refractory PAF managed with either RFCA or CB ablation, to compare the cost-effectiveness of the 2 procedures. Data related to clinical outcomes and costs in this model were obtained from a retrospective 12-month follow-up study in patients in China and from related literature. The incremental cost-effectiveness ratio (ICER) over a 10-year time period was calculated and compared against the willingness-to-pay (WTP) threshold. We used a 1-way sensitivity analysis and a probabilistic sensitivity analysis (PSA) to access the structural uncertainty and the parameter uncertainty, respectively. FINDINGS: Over a 10-year time horizon, the total costs per patient of RFCA and CB ablation were ¥98,164.04 (US $15,339.57; €13,058.94) and ¥107,542.37 ($16,805.07; €14,306.55), respectively, and quality-adjusted life-years (QALYs) gained were 5.47 and 5.43, respectively. The ICER ratio was -¥224,365.01 (-$35,060.32; -€29,847.68) per QALY, indicating that RFCA is associated with greater QALYs and lower costs than CB ablation. The 1-way sensitivity analysis demonstrated that the model results were most sensitive to the odds ratio of the atrial fibrillation recurrence within 12 months in the RFCA group versus the CB ablation group, the cost of RFCA, and the perioperative stroke risk with RFCA. According to the results of the PSA, RFCA was associated with a high probability of being cost-effective (99.48%) compared with CB ablation at a WTP threshold of ¥161,940 ($25,305.50; €21,543.17) per QALY. IMPLICATIONS: Our analysis indicates that RFCA is cost-saving compared with CB ablation in the treatment of patients with PAF in China, based on better QALYs and lower costs over a 10-year time horizon, from the payer's perspective.


Subject(s)
Atrial Fibrillation/surgery , Catheter Ablation/methods , Quality-Adjusted Life Years , Aged , China , Cost-Benefit Analysis , Female , Follow-Up Studies , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome
8.
Drug Dev Ind Pharm ; 44(9): 1506-1511, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29676171

ABSTRACT

In order to make a further optimization of process design via increasing the stability of design space, we brought in the model of Support Vector Regression (SVR). In this work, the extraction of podophyllotoxin was researched as a case study based on Quality by Design (QbD). We compared the fitting effect of SVR and the most used quadratic polynomial model (QPM) in QbD, and an analysis was made between the two design spaces obtained by SVR and QPM. As a result, the SVR stayed ahead of QPM in prediction accuracy, the stability of model and the generalization ability. The introduction of SVR into QbD made the extraction process of podophyllotoxin well designed and easier to control. The better fitting effect of SVR improved the application effect of QbD and the universal applicability of SVR, especially for non-linear, complicated and weak-regularity problems, widened the application field of QbD.


Subject(s)
Podophyllotoxin/chemistry , Algorithms , Drug Design , Models, Statistical
9.
Redox Biol ; 14: 509-521, 2018 04.
Article in English | MEDLINE | ID: mdl-29101900

ABSTRACT

Glutaredoxin 2 (GRX2), a mitochondrial glutathione-dependent oxidoreductase, is central to glutathione homeostasis and mitochondrial redox, which is crucial in highly metabolic tissues like the heart. Previous research showed that absence of Grx2, leads to impaired mitochondrial complex I function, hypertension and cardiac hypertrophy in mice but the impact on mitochondrial structure and function in intact cardiomyocytes and in humans has not been explored. We hypothesized that Grx2 controls cardiac mitochondrial dynamics and function in cellular and mouse models, and that low expression is associated with human cardiac dysfunction. Here we show that Grx2 absence impairs mitochondrial fusion, ultrastructure and energetics in primary cardiomyocytes and cardiac tissue. Moreover, provision of the glutathione precursor, N-acetylcysteine (NAC) to Grx2-/- mice did not restore glutathione redox or prevent impairments. Using genetic and histopathological data from the human Genotype-Tissue Expression consortium we demonstrate that low GRX2 is associated with fibrosis, hypertrophy, and infarct in the left ventricle. Altogether, GRX2 is important in the control of cardiac mitochondrial structure and function, and protects against human cardiac pathologies.


Subject(s)
Energy Metabolism , Glutaredoxins/metabolism , Heart Diseases/metabolism , Mitochondrial Dynamics , Acetylcysteine/therapeutic use , Animals , Cardiomegaly/genetics , Cardiomegaly/metabolism , Cardiomegaly/pathology , Cardiomegaly/prevention & control , Cells, Cultured , Glutaredoxins/genetics , Heart Diseases/genetics , Heart Diseases/pathology , Heart Diseases/prevention & control , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitochondria/metabolism , Mitochondria/pathology , Oxidation-Reduction , Oxidative Stress , Protective Factors
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(10): 2680-5, 2015 Oct.
Article in Chinese | MEDLINE | ID: mdl-26904799

ABSTRACT

Pulsed corona discharge in atmosphere has been widely regarded as an efficient flue gas treatment technology for the generation of active radical species, such as the OH radicals. The spatial distribution of OH radicals generated by pulsed corona discharge plays an important role in decomposing pollutants. The two-dimensional (2-D) distribution of OH radicals of positive wire--plate pulsed corona discharge was detected using laser-induced fluorescence (LIF). The influence of relative humidity (RH) and oxygen concentration on the 2-D distribution of OH radicals were investigated. The results indicated that the 2-D distribution of OH radicals was characterized by a fan-shaped distribution from the wire electrode to plate electrode, and both the maximum values of vertical length and horizontal width of the fan area was less than 1 cm. The 2-D distribution area of OH radicals increased significantly with increasing the RH and the optimum condition was 65% RH. The optimal level of the oxygen concentration for the 2-D distribution area of OH radicals was 2%. The process of OH radical generation and 2-D distribution area of OH radicals were significantly interfered when the oxygen concentration was larger than 15%. The total quenching rate coefficients for different RH values and oxygen concentration in this study were used to calculate the fluorescence yield of OH radical. The fluorescence yield, which is the ratio between the emission rate (Einstein coefficient) and the sum of the emission rate and quenching rate, was used to normalize the 2-D distribution area of OH radicals. The fluorescence yield of OH radical decreased with increasing the RH and oxygen concentration linearly and rapidly. It was also found that compared with the RH, the influence of the oxygen concentration had more notable effect on the fluorescence yield of OH radical and 2-D distribution area of OH radicals.

11.
J Biol Chem ; 289(21): 14812-28, 2014 May 23.
Article in English | MEDLINE | ID: mdl-24727547

ABSTRACT

Glutaredoxin-2 (Grx2) modulates the activity of several mitochondrial proteins in cardiac tissue by catalyzing deglutathionylation reactions. However, it remains uncertain whether Grx2 is required to control mitochondrial ATP output in heart. Here, we report that Grx2 plays a vital role modulating mitochondrial energetics and heart physiology by mediating the deglutathionylation of mitochondrial proteins. Deletion of Grx2 (Grx2(-/-)) decreased ATP production by complex I-linked substrates to half that in wild type (WT) mitochondria. Decreased respiration was associated with increased complex I glutathionylation diminishing its activity. Tissue glucose uptake was concomitantly increased. Mitochondrial ATP output and complex I activity could be recovered by restoring the redox environment to that favoring the deglutathionylated states of proteins. Grx2(-/-) hearts also developed left ventricular hypertrophy and fibrosis, and mice became hypertensive. Mitochondrial energetics from Grx2 heterozygotes (Grx2(+/-)) were also dysfunctional, and hearts were hypertrophic. Intriguingly, Grx2(+/-) mice were far less hypertensive than Grx2(-/-) mice. Thus, Grx2 plays a vital role in modulating mitochondrial metabolism in cardiac muscle, and Grx2 deficiency leads to pathology. As mitochondrial ATP production was restored by the addition of reductants, these findings may be relevant to novel redox-related therapies in cardiac disease.


Subject(s)
Glutaredoxins/metabolism , Glutathione/metabolism , Myocardium/metabolism , Oxidative Phosphorylation , Adenosine Triphosphate/metabolism , Animals , Electron Transport Complex I/metabolism , Fibrosis/genetics , Glutaredoxins/genetics , Hypertension/genetics , Hypertrophy, Left Ventricular/genetics , Hypertrophy, Left Ventricular/metabolism , Immunoblotting , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Microscopy, Electron , Mitochondria, Heart/metabolism , Mitochondria, Heart/ultrastructure , Myocardium/pathology , Organ Size/genetics , Oxidation-Reduction
12.
J Biol Chem ; 288(12): 8365-8379, 2013 Mar 22.
Article in English | MEDLINE | ID: mdl-23335511

ABSTRACT

Glutathionylation has emerged as a key modification required for controlling protein function in response to changes in cell redox status. Recently, we showed that the glutathionylation state of uncoupling protein-3 (UCP3) modulates the leak of protons back into the mitochondrial matrix, thus controlling reactive oxygen species production. However, whether or not UCP3 glutathionylation is mediated enzymatically has remained unknown because previous work relied on the use of pharmacological agents, such as diamide, to alter the UCP3 glutathionylation state. Here, we demonstrate that glutaredoxin-2 (Grx2), a matrix oxidoreductase, is required to glutathionylate and inhibit UCP3. Analysis of bioenergetics in skeletal muscle mitochondria revealed that knock-out of Grx2 (Grx2(-/-)) increased proton leak in a UCP3-dependent manner. These effects were reversed using diamide, a glutathionylation catalyst. Importantly, the increased leak did not compromise coupled respiration. Knockdown of Grx2 augmented proton leak-dependent respiration in primary myotubes from wild type mice, an effect that was absent in UCP3(-/-) cells. These results confirm that Grx2 deactivates UCP3 by glutathionylation. To our knowledge, this is the first enzyme identified to regulate UCP3 by glutathionylation and is the first study on the role of Grx2 in the regulation of energy metabolism.


Subject(s)
Glutaredoxins/physiology , Ion Channels/metabolism , Mitochondrial Proteins/metabolism , Protons , Adenosine Triphosphate/metabolism , Animals , Cells, Cultured , Citric Acid Cycle , Diamide/pharmacology , Electron Transport Complex I/metabolism , Energy Metabolism , Glutaredoxins/genetics , Glutaredoxins/metabolism , Glutathione/metabolism , Homeostasis , Hydrogen Peroxide/pharmacology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitochondria, Liver/metabolism , Mitochondria, Muscle/metabolism , Oxidants/pharmacology , Oxidation-Reduction , Oxidative Stress , Oxygen Consumption , Primary Cell Culture , Protein Processing, Post-Translational , Reactive Oxygen Species/metabolism , Uncoupling Protein 3
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(5): 1157-61, 2012 May.
Article in Chinese | MEDLINE | ID: mdl-22827044

ABSTRACT

The spectrum of excited N2 molecules and ions was measured by optical emission spectroscopy in pulsed corona discharge with a wire-to-plate reactor. The ratio of emission intensities emitted by the excited molecules and ions of N2 was compared with numerical simulation to determine average electron energies and electric field distributions. Within 2 cm distance from wire electrode in horizontal and vertical directions, electric field and average electron energies appear to be in the ranges of 11.05 19.6 MV x m(-1) and 10.10-13.92 eV respectively; as the distance increases, average electron energies and electric field show a similar trend: first decrease and then increase. Chemically active species, such as OH, O and O3, can be generated through the energetic electron collisions with H2O and O2 directly or indirectly. For the NO oxidation, there is no coexistence of NO and O3, whereas there is a coexistence of NO and OH. NO is oxidized by O3 or O more efficiently than by OH radical.

14.
FASEB J ; 26(1): 363-75, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21940996

ABSTRACT

Reduced glutathione (GSH) is the major determinant of redox balance in mitochondria and as such is fundamental in the control of cellular bioenergetics. GSH is also the most important nonprotein antioxidant molecule in cells. Surprisingly, the effect of redox environment has never been examined in skeletal muscle and brown adipose tissue (BAT), two tissues that have exceptional dynamic range and that are relevant to the development of obesity and related diseases. Here, we show that the redox environment plays crucial, yet divergent, roles in modulating mitochondrial bioenergetics in skeletal muscle and BAT. Skeletal muscle mitochondria were found to naturally have a highly reduced environment (GSH/GSSG≈46), and this was associated with fairly high (∼40%) rates of state 4 (nonphosphorylating) respiration and decreased reactive oxygen species (ROS) emission. The deglutathionylation of uncoupling protein 3 (UCP3) following an increase in the reductive potential of mitochondria results in a further increase in nonphosphorylating respiration (∼20% in situ). BAT mitochondria were found to have a much more oxidized status (GSH/GSSG≈13) and had basal reactive oxygen species emission that was higher (∼250% increase in ROS generation) than that in skeletal muscle mitochondria. When redox status was subsequently increased (i.e., more reduced), UCP1-mediated uncoupling was more sensitive to GDP inhibition. Surprisingly, BAT was found to be devoid of glutaredoxin-2 (Grx2) expression, while there was abundant expression in skeletal muscle. Taken together, these findings reveal the importance of redox environment in controlling bioenergetic functions in both tissues, and the highly unique characteristics of BAT in this regard.


Subject(s)
Adipose Tissue, Brown/metabolism , Energy Metabolism/physiology , Mitochondria, Muscle/metabolism , Muscle, Skeletal/metabolism , Animals , Cold Temperature , Dithiothreitol/pharmacology , Glutathione/metabolism , Glutathione Disulfide/metabolism , Ion Channels/metabolism , Male , Membrane Potential, Mitochondrial/physiology , Mice , Mice, Inbred C57BL , Mitochondria, Muscle/drug effects , Mitochondrial Proteins/metabolism , Organ Specificity , Oxidation-Reduction/drug effects , Oxygen Consumption/physiology , Protons , Thermogenesis/physiology , Uncoupling Protein 2 , Uncoupling Protein 3
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(11): 2896-900, 2011 Nov.
Article in Chinese | MEDLINE | ID: mdl-22242480

ABSTRACT

In order to get extensive knowledge of wire-to-plate pulsed corona discharge reactor, the influences of different diameters of wire electrode, different wire-to-plate and wire-to-wire spacing on OH radical generation were experimentally investigated under atmospheric pressure based on emission spectrum, and the spatial distribution of OH radicals in the electric field was also discussed in detail The results showed that OH radicals decrease along the X-axis, and the activation radius is approximately 20 mm; showing a trend of first increase and then decrease along the Y-axis, with the activation radius being more than 30 mm. OH radical has small change as the diameter of wire electrode changes below 2 mm, with a sharp decline as the diameter continues to increase. OH radical emission intensity increases as wire-to-wire spacing increases and decrease as wire-to-plate spacing increases.

16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(11): 2901-5, 2011 Nov.
Article in Chinese | MEDLINE | ID: mdl-22242481

ABSTRACT

Streamer plays a key role in the process of OH radical generation. The propagation of primary and secondary streamers of positive wire-plate pulsed corona discharge was observed using a short gate ICCD in air environment. The influence of the applied voltage on the properties was investigated. It was shown that the primary streamer propagation velocity, electric coverage and length of secondary streamer increased significantly with increasing the applied voltage. Then 2-D OH distribution was investigated by the emission spectrum. With the analysis of the OH emission spectra, the distribution of OH radicals showed a trend of decreasing from the wire electrode to its circumambience. Compared with the streamer propagation trace, the authors found that OH radical distribution and streamer are in the same area. Both OH radical concentration and the intensity of streamer decreased when far away from the wire electrode.

17.
J Biol Chem ; 285(8): 5748-58, 2010 Feb 19.
Article in English | MEDLINE | ID: mdl-20032466

ABSTRACT

Oxidative stress in skeletal muscle is a hallmark of various pathophysiologic states that also feature increased reliance on long-chain fatty acid (LCFA) substrate, such as insulin resistance and exercise. However, little is known about the mechanistic basis of the LCFA-induced reactive oxygen species (ROS) burden in intact mitochondria, and elucidation of this mechanistic basis was the goal of this study. Specific aims were to determine the extent to which LCFA catabolism is associated with ROS production and to gain mechanistic insights into the associated ROS production. Because intermediates and by-products of LCFA catabolism may interfere with antioxidant mechanisms, we predicted that ROS formation during LCFA catabolism reflects a complex process involving multiple sites of ROS production as well as modified mitochondrial function. Thus, we utilized several complementary approaches to probe the underlying mechanism(s). Using skeletal muscle mitochondria, our findings indicate that even a low supply of LCFA is associated with ROS formation in excess of that generated by NADH-linked substrates. Moreover, ROS production was evident across the physiologic range of membrane potential and was relatively insensitive to membrane potential changes. Determinations of topology and membrane potential as well as use of inhibitors revealed complex III and the electron transfer flavoprotein (ETF) and ETF-oxidoreductase, as likely sites of ROS production. Finally, ROS production was sensitive to matrix levels of LCFA catabolic intermediates, indicating that mitochondrial export of LCFA catabolic intermediates can play a role in determining ROS levels.


Subject(s)
Electron Transport Complex III/metabolism , Electron-Transferring Flavoproteins/metabolism , Fatty Acids/metabolism , Hydrogen Peroxide/metabolism , Iron-Sulfur Proteins/metabolism , Mitochondria, Liver/metabolism , Mitochondria, Muscle/metabolism , Oxidoreductases Acting on CH-NH Group Donors/metabolism , Animals , Electron Transport/physiology , Male , Membrane Potential, Mitochondrial/physiology , Mice
18.
PLoS One ; 3(3): e1759, 2008 Mar 12.
Article in English | MEDLINE | ID: mdl-18335035

ABSTRACT

The yeast sir2 gene and its orthologues in Drosophila and C. elegans have well-established roles in lifespan determination and response to caloric restriction. We have studied mice carrying two null alleles for SirT1, the mammalian orthologue of sir2, and found that these animals inefficiently utilize ingested food. These mice are hypermetabolic, contain inefficient liver mitochondria, and have elevated rates of lipid oxidation. When challenged with a 40% reduction in caloric intake, normal mice maintained their metabolic rate and increased their physical activity while the metabolic rate of SirT1-null mice dropped and their activity did not increase. Moreover, CR did not extend lifespan of SirT1-null mice. Thus, SirT1 is an important regulator of energy metabolism and, like its orthologues from simpler eukaryotes, the SirT1 protein appears to be required for a normal response to caloric restriction.


Subject(s)
Energy Intake , Energy Metabolism/physiology , Sirtuins/physiology , Animals , Calorimetry , Hormones/blood , Mice , Mice, Knockout , Mitochondria, Liver/metabolism , Reactive Oxygen Species/metabolism , Sirtuin 1
19.
Mol Cancer Ther ; 5(9): 2158-64, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16985048

ABSTRACT

The ability of cancer cells to undergo invasion and migration is a prerequisite for tumor metastasis. Rho, a Ras-related small GTPase, and the Rho-associated coiled coil-containing protein kinases (Rho kinases, ROCK1 and ROCK2) are key regulators of focal adhesion, actomyosin contraction, and thus cell motility. Inhibitors of this pathway have been shown to inhibit tumor cell motility and metastasis. Here, we show that fasudil [1-(5-isoquinolinesulfonyl)-homopiperazine], an orally available inhibitor of Rho kinases, and its metabolite 1-(hydroxy-5-isoquinoline sulfonyl-homopiperazine) (fasudil-OH) modify tumor cell morphology and inhibit tumor cell migration and anchorage-independent growth. In addition, we show that fasudil inhibited tumor progression in three independent animal models. In the MM1 peritoneal dissemination model, tumor burden and ascites production were reduced by > 50% (P < 0.05). In the HT1080 experimental lung metastasis model, fasudil decreased lung nodules by approximately 40% (P < 0.05). In the orthotopic breast cancer model with MDA-MB-231, there were 3-fold more tumor-free mice in the fasudil-treated group versus saline control group (P < 0.01). Fasudil has been approved for the treatment of cerebral vasospasm and associated cerebral ischemic symptoms. In patients, fasudil is well tolerated without any serious adverse reactions. Therefore, the concept of Rho kinase inhibition as an antimetastatic therapy for cancer can now be clinically explored.


Subject(s)
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , Breast Neoplasms/drug therapy , Fibrosarcoma/drug therapy , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , rho-Associated Kinases/antagonists & inhibitors , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Animals , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cell Growth Processes/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Disease Progression , Female , Fibrosarcoma/enzymology , Fibrosarcoma/pathology , Humans , Male , Mice , Mice, Nude , Rats , Xenograft Model Antitumor Assays
20.
Gene ; 380(2): 111-9, 2006 Oct 01.
Article in English | MEDLINE | ID: mdl-16879932

ABSTRACT

The detection and purification of proteins are often time-consuming and frequently involve complicated protocols. The addition of a peptide tag to recombinant proteins can make this process more efficient. Many of the commonly used tags, such as Flagtrade mark, Myc, HA and V5 are recognized by specific monoclonal antibodies and therefore, allow immunoaffinity-based purification. Enhancing the current scope of flexibility in using diverse peptide tags, we report here the development of a novel, short polypeptide tag (Tab2) for detection and purification of recombinant proteins. The Tab2 epitope corresponds to the NH2-terminal seven amino acid residues of human TGFalpha. A monoclonal anti-Tab2 antibody was raised and characterized. To investigate the potential of this peptide sequence as a novel tag for recombinant proteins, we expressed several different recombinant proteins containing this tag in E. coli, baculovirus, and mammalian cells. The data presented demonstrates the Tab2 tag-anti-Tab2 antibody combination is a reliable tool enabling specific Western blot detection, FACS analysis, and immunoprecipitation as well as non-denaturing protein affinity purification.


Subject(s)
Chromatography, Affinity/methods , Epitopes/chemistry , Peptide Fragments/immunology , Recombinant Fusion Proteins/isolation & purification , Transforming Growth Factor alpha/genetics , Amino Acid Motifs/genetics , Animals , Antibodies, Monoclonal/immunology , Antibody Specificity/immunology , Cells, Cultured , Cloning, Molecular , Enzyme-Linked Immunosorbent Assay/methods , Flow Cytometry/methods , Genetic Vectors/chemical synthesis , Humans , Immunoprecipitation/methods , Insecta , Peptide Fragments/genetics , Phosphotransferases/genetics , Phosphotransferases/isolation & purification , Phosphotransferases/metabolism , Protein Binding/immunology , Protein Structure, Tertiary/genetics , Receptors, Cell Surface/genetics , Receptors, Cell Surface/isolation & purification , Receptors, Cell Surface/metabolism , Recombinant Fusion Proteins/chemical synthesis , Recombinant Fusion Proteins/immunology , Transforming Growth Factor alpha/chemistry , Transforming Growth Factor alpha/metabolism
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