In the chemical looping with oxygen uncoupling(CLOU)process,CuO is a promising material due to the high oxygen carrier capacity and exothermic reaction in fuel reactor but limited by the low melting point.The combusti...In the chemical looping with oxygen uncoupling(CLOU)process,CuO is a promising material due to the high oxygen carrier capacity and exothermic reaction in fuel reactor but limited by the low melting point.The combustion rate of carbon is faster than the decoupling rate of oxygen carrier(OC).Hence,high temperature tolerance and rapid oxygen release rate of CuO modified by three different ores were investigated in this study.The kinetics analysis of oxygen decoupling with Cu-based oxygen carriers was also evaluated.Results showed that CuO modified by chrysolite had faster oxygen release rate than that of CuO.Limestone showed obvious positive effect on the oxidization process.The selected OCs could keep stable in at least 20 cycles,for about 1200 min.Shrinking core model(SCM)fitted well for the decoupling process in the temperature range of 1123-1223 K.Reduction rate kinetic information may aid in the development of chemical looping with oxygen uncoupling(CLOU)technologies during reactor design and process modeling.Ternary doped copper oxide with chrysolite and limestone could improve the reactivity of CuO in decoupling and coupling process and also improve the high temperature tolerance.展开更多
BACKGROUND Uncoupling protein 1(UCP1)plays a pivotal role in modulating energy expen-diture and maintaining metabolic homeostasis within brown and beige adipo-cytes.It has also been implicated in tumorigenesis.AIM To ...BACKGROUND Uncoupling protein 1(UCP1)plays a pivotal role in modulating energy expen-diture and maintaining metabolic homeostasis within brown and beige adipo-cytes.It has also been implicated in tumorigenesis.AIM To investigate the expression and function of UCP1 in gastric cancer(GC).METHODS UCP1 protein expression in 211 GC tissues was examined using immunohisto-chemistry.Bisulfite sequencing PCR(BSP)was used to detect the methylation status of the UCP1 promoter in GC cell lines and tissues.The relationship between UCP1 expression and clinicopathological parameters was analyzed.CCK8,scratch,transwell,and flow cytometry assays were carried out to analyze the proliferation,migration,invasion,and apoptosis of GC cell lines after knockdown or overexpression of UCP1 in vitro.A nude mouse tumor xenograft model was used to investigate the function of UCP1 in vivo.RNA sequencing,Kyoto Ency-clopedia of Genes and Genomes analysis,and Rap1 pull-down assays were performed to identify the pathway associated with UCP1.RESULTS Loss of UCP1 was significantly associated with gender,poor differentiation,and advanced TNM stage of GC.Hypermethylation of UCP1 was confirmed in GC cells and tumor tissues by BSP.Overexpression of UCP1 suppressed GC cell proliferation,migration,and invasion,and it promoted apoptosis in vitro.UCP1 overexpression also suppressed GC tumor growth in vivo.Moreover,overexpression of UCP1 in GC cells resulted in a significant decrease in active Rap1 protein levels,whereas downregulation of UCP1 markedly enhanced Rap1 activity.CONCLUSION UCP1 downregulation in GC through promoter hypermethylation is related to the progression of GC,indicating that UCP1 plays a role as a tumor suppressor in GC.It regulates Rap1 signaling and may be a potential therapeutic target in GC.展开更多
Overall 5-years survival of pancreatic cancer patients is nearly 5%,making this cancer type one of the most lethal neoplasia.Furthermore,the incidence rate of pancreatic cancer has a growing trend that determines a co...Overall 5-years survival of pancreatic cancer patients is nearly 5%,making this cancer type one of the most lethal neoplasia.Furthermore,the incidence rate of pancreatic cancer has a growing trend that determines a constant increase in the number of deceases caused by this pathology.The poor prognosis of pancreatic cancer is mainly caused by delayed diagnosis,early metastasis of tumor,and resistance to almost all tested cytotoxic drugs.In this respect,the identification of novel potential targets for new and efficient therapies should be strongly encouraged in order to improve the clinical management of pancreatic cancer.Some studies have shown that the mitochondrial uncoupling protein 2(UCP2) is over-expressed in pancreatic cancer as compared to adjacent normal tissues.In addition,recent discoveries established a key role of UCP2 in protecting cancer cells from an excessive production of mitochondrial superoxide ions and in the promotion of cancer cell metabolic reprogramming,including aerobic glycolysis stimulation,promotion of cancer progression.These observations together with the demonstration that UCP2 repression can synergize with standard chemotherapy to inhibit pancreatic cancer cell growth provide the molecular rationale to consider UCP2 as a potential therapeutic target for pancreatic cancer.In this editorial,recent advances describing the relationship between cancer development and mitochondrial UCP2 activity are critically provided.展开更多
Objective:To explore the effects of acupuncture on the expression of uncoupling protein 1（UCP1）gene of brown adipose tissue （BAT）in obese rats.Methods:The expression of UCP1gene ofBAT was determined with RT-PCR te...Objective:To explore the effects of acupuncture on the expression of uncoupling protein 1（UCP1）gene of brown adipose tissue （BAT）in obese rats.Methods:The expression of UCP1gene ofBAT was determined with RT-PCR technique.The changes of body weight,Lee’s index,body fat,andthe expression of UCP1gene of BAT in obese rats were observed before and after acupuncture.Results:The body weight,Lee’s indeX,body fat in obese rats were all markedly higher than those in normal rats,but the expression of UCP1gene of BAT in obese rats was all lower than that in normal rats.There werenegative correlation between the Obesity index and the expression of UCP1gent in BAT.After acupunc-ture the marked effect of weight loss was achieved while the expression of UCP1gene of BAT Obviously in-creased in obese rats.Conclusion:The abnormal reduction for expression of UCP1gene of BAT might bean important cause for the obesity.To promote the expression of UCP1in obese organism might be an im-portant cellular and mole展开更多
Reactive oxygen species（ROS） are free radicals thought to mediate the neurotoxic effects of several neurodegenerative disorders.In the central nervous system,ROS can also trigger a phenotypic switch in both astrocyt...Reactive oxygen species（ROS） are free radicals thought to mediate the neurotoxic effects of several neurodegenerative disorders.In the central nervous system,ROS can also trigger a phenotypic switch in both astrocytes and microglia that further aggravates neurodegeneration,termed reactive gliosis.Negative regulators of ROS,such as mitochondrial uncoupling protein 2（UCP2） are neuroprotective factors that decrease neuron loss in models of stroke,epilepsy,and parkinsonism.However,it is unclear whether UCP2 acts purely to prevent ROS production,or also to prevent gliosis.In this review article,we discuss published evidence supporting the hypothesis that UCP2 is a neuroprotective factor both through its direct effects in decreasing mitochondrial ROS and through its effects in astrocytes and microglia.A major effect of UCP2 activation in glia is a change in the spectrum of secreted cytokines towards a more anti-inflammatory spectrum.There are multiple mechanisms that can control the level or activity of UCP2,including a variety of metabolites and micro RNAs.Understanding these mechanisms will be key to exploitingthe protective effects of UCP2 in therapies for multiple neurodegenerative conditions.展开更多
The effect of target-directed regulation of the uncoupling protein-2 （UCP-2） gene expression on the ischemia-reperfusion injury of hepatocytes under different conditions was investigated. The expression plasmid and ...The effect of target-directed regulation of the uncoupling protein-2 （UCP-2） gene expression on the ischemia-reperfusion injury of hepatocytes under different conditions was investigated. The expression plasmid and RNAi plasmid targeting UCP-2 gene were constructed and trans- fected into normal hepatocytes and fatty liver cells, respectively. The expression of UCP-2 mRNA was detected by real time PCR. The cells were divided into normal cell group （NCG）, group of normal cells transfected with empty vector （EVNCG）, group of normal cells transfected with expression plasmid （EPNCG）, fatty liver cell group （FCG） and group of fatty liver cells transfected with RNAi plasmid （RPFCG）. The ischemia-reperfusion model in vitro was established. One, 6, 12 and 24 h after reperfusion, Annexin V/PI flow cytometry was used to measure cell necrosis rate, apoptosis rate and survival rate. Simultaneously, the intracellular ATP, ROS and MDA levels were determined. The re- sults showed that 1, 6, 12 and 24 h after ischemia-reperfusion, the intracellular ROS, MDA and ATP levels and cell survival rate in EPNCG were significantly lower, and cell necrosis rate significantly higher than in NCG and EVNCG, but there was no significant difference in apoptosis rate among NCG, EVNCG and EPNCG （P〉005）. Six, 12 and 24 h after reperfusion there was no significant dif- ference in ROS, MDA levels and apoptosis rate between FCG and RPFCG （P〉0.05）, but the ATP level and survival rate of cells in RPFCG were higher than in FCG （P〈0.05）. It was concluded that down-regulation of the UCP-2 gene expression in steatotic hepatocytes could alleviate the ische- mia-reperfusion injury of liver cells.展开更多
AIM: To analyze the expression of uncoupling protein 2(UCP2) in retinal pigment epithelium(RPE) cells at the different human age, further explore the possible new target of RPE cells protection.METHODS: Adult retinal ...AIM: To analyze the expression of uncoupling protein 2(UCP2) in retinal pigment epithelium(RPE) cells at the different human age, further explore the possible new target of RPE cells protection.METHODS: Adult retinal pigment epithelial-19(ARPE-19) cells and the primary RPE cells at the different age(9-20 y,50-55 y, 60-70 y, >70 y) were cultured and harvested. The expression of UCP2 in these cells was detected by reverse transcription-polymerase chain reaction(RT-PCR), Western blot and confocal microscopy.RESULTS: Cells from the donors more than 60 y are larger and more fibroblastic in appearance compared to ARPE-19 cells and those primary cultures obtained from the younger individuals by using phase-contrast micrographs. Results of RT-PCR, Western blot and confocal microscopy all showed that UCP2 was highly expressed in ARPE-19 cells and in the younger primary cultured human RPE cells at the age of 9-20 y and 50-55 y, whereas lower expression of UCP2 was measured in the older primary cultured human RPE cells at the age more than 60 y.CONCLUSION: Expression of UCP2 gene is decreased in aged RPE cells, promoting the lower ability of anti-oxidation in these cells. It is indicated that UCP2 gene might be a new target for protecting the cells from oxidative stress damage.展开更多
AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,...AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,which serve as a model for enteroendocrine L-cells,by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid.Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling.NCI-H716 cells were transiently transfected with a small interfering RNA(siRNA) that targets UCP2(siUCP2) or with a nonspecific siRNA using Lipofectamine 2000.The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.RESULTS:Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells.NCI-H716 cells that secreted GLP-1 also expressed UCP2.Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid(the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells,P < 0.05).In an experiment to determine dose dependence,stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium;10 mmol oleic acid diminished the release of GLP-1.Furthermore,GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%,as compared with NCI-H716 cells that were transfected with a non-specific siRNA(P < 0.01).CONCLUSION:UCP2 affected GLP-1 secretion induced by oleic acid.UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.展开更多
Background: Pancreatic ductal adenocarcinoma(PDAC) is a disease of the elderly mostly because its development from preneoplastic lesions depends on the accumulation of gene mutations and epigenetic alterations over ti...Background: Pancreatic ductal adenocarcinoma(PDAC) is a disease of the elderly mostly because its development from preneoplastic lesions depends on the accumulation of gene mutations and epigenetic alterations over time. How aging of non-cancerous tissues of the host affects tumor progression, however, remains largely unknown. Methods: We took advantage of a model of accelerated aging, uncoupling protein 2-deficient( Ucp2 knockout, Ucp2 KO) mice, to investigate the growth of orthotopically transplanted Ucp2 wild-type(WT) PDAC cells(cell lines Panc02 and 6606PDA) in vivo and to study strain-dependent differences of the PDAC microenvironment. Results: Measurements of tumor weights and quantification of proliferating cells indicated a significant growth advantage of Panc02 and 6606PDA cells in WT mice compared to Ucp2 KO mice. In tumors in the knockout strain, higher levels of interferon-γ m RNA despite similar numbers of tumor-infiltrating T cells were observed. 6606PDA cells triggered a stronger stromal reaction in Ucp2 KO mice than in WT animals. Accordingly, pancreatic stellate cells from Ucp2 KO mice proliferated at a higher rate than cells of the WT strain when they were incubated with conditioned media from PDAC cells. Conclusions: Ucp2 modulates PDAC microenvironment in a way that favors tumor progression and implicates an altered stromal response as one of the underlying mechanisms.展开更多
Oxygen uncoupling characteristics of a natural manganese ore and a perovskitetype oxide CaMn_(0.5)Ti0_(37)5Fe_(0.125)O_(3)were studied by using a microfluidized bed thermogravimetric analysis(MFBTGA)technology which i...Oxygen uncoupling characteristics of a natural manganese ore and a perovskitetype oxide CaMn_(0.5)Ti0_(37)5Fe_(0.125)O_(3)were studied by using a microfluidized bed thermogravimetric analysis(MFBTGA)technology which is based on a realtime mass measurement of fluidizing particles inside a bubbling bed reactor.The chemical stability,kinetics of the oxygen release and uptake reactions and fluidization property were investigated and the experimental data measured by MFBTGA were compared with the results in a regular TGA instrument(TGA Q500).The regular TGA Q500 results show the reactivity of both the manganese ore and perovskite oxide are stable for multi cycles,and the oxygen uncoupling capacity of the manganese ore is~1.2%(mass)which is~2 times higher than that of the perovskite oxide.However,the experimental results from the MFBTGA indicated that there is a serious agglomeration for the manganese ore.A very important finding is that the reaction rate of oxygen release and oxygen uptake of the perovskite oxide measured by the MFBTGA are~2 and~4 times faster than that of testedby the TGA Q500.We can conclude that MFBTGA is a very useful tool to measure the reactivity stability and kinetics of oxygen carriers in highthroughput analysis instead of the regular TGA.展开更多
BACKGROUND： Uncoupling protein 2 （UCP2） has been suggested to inhibit mitochondrial production of reactive oxygen species （ROS） by decreasing the mitochondrial membrane potential. Experimental acute pancreatitis ...BACKGROUND： Uncoupling protein 2 （UCP2） has been suggested to inhibit mitochondrial production of reactive oxygen species （ROS） by decreasing the mitochondrial membrane potential. Experimental acute pancreatitis is associated with increased UCP2 expression, whereas UCP2 deficiency retards regeneration of aged mice from acute pancreatitis. Here, we have addressed biological and molecular functions of UCP2 in pancreatic stellate cells （PSCs）, which are involved in pancreatic wound repair and fibrogenesis. METHODS： PSCs were isolated from 12 months old （aged） UCP2^-/- mice and animals of the wild-type （WT） strain C57BL/6. Proliferation and cell death were assessed by em- ploying trypan blue staining and a 5-bromo-2＇-deoxyuridine incorporation assay. Intracellular fat droplets were visualized by oil red O staining. Levels of mRNA were determined by RT-PCR, while protein expression was analyzed by immunoblotting and immunofluorescence analysis. Intracellular ROS levels were measured with 2＇,7＇-dichlorofluorescin diacetate. Expression of senescence-associated β-galactosidase （SA β-Gal） was used as a surrogate marker of cellular senescence. RESULTS： PSCs derived from UCP2^-/- mice proliferated at a lower rate than cells from WT mice. In agreement with this observation, the UCP2 inhibitor genipin displayed dose- dependent inhibitory effects on WT PSC growth. Interestingly, ROS levels in PSCs did not differ between the two strains, and PSCs derived from UCP2^-/- mice did not senesce faster than those from corresponding WT cells. PSCs from UCP2^-/- mice and WT animals were also indistinguishable with respect to the activation-dependent loss of intracellular fat droplets, expression of the activation marker α-smooth muscle actin, type I collagen and the autocrine/paracrine mediators interleukin-6 and transforming growth factor-I~ 1. CONCLUSIONS： A reduced proliferative capacity of PSC from aged UCP2^-/- mice may contribute to the retarded regeneration after acute pancreatitis. Apart from their slower growth, PSC of UCP2^-/- mice displayed no functional abnormalities. The antifibrotic potential of UCP2 inhibitors deserves further attention.展开更多
Objective: Determine the role of uncoupling protein 2 (UCP2) in the myocardial apoptosis of diabetic mellitus(DM). Methods: DM animal models were induced by streptozotocinon (STZ) on UCP2 knock-out mice (UCP2KO) and w...Objective: Determine the role of uncoupling protein 2 (UCP2) in the myocardial apoptosis of diabetic mellitus(DM). Methods: DM animal models were induced by streptozotocinon (STZ) on UCP2 knock-out mice (UCP2KO) and wild-type mice (WT), which were reared for 7 and 28 days after successful modeling, respectively. The expressions of relative protein for myocardial apoptosis, pro-caspase-9, were investigated using western blot. However, the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) was used to explain apoptosis at the DNA level. Results: Image analysis showed that the expression of pro-caspase-9 protein levels increased slightly in UCP-/- + DM-7-day group comparing with DM-7-day group (P > 0.05). The expression of pro-caspase-9 protein levels increased significantly (P < 0.05)in UCP-/- + DM-28-day group comparing with DM-28-day group. TUNEL analysis indicated that UCP2 reduced the number of apoptotic myocytes in the DM-28-day group by 70% in comparison to DM-7-day group by 30% (P < 0.05). Conclusion UCP2 may be one of the most important factors that contribute to the myocardial apoptosis of DM.展开更多
According to the structure of explosive charge in rock blasting, a physical model has been set up in this paper. Based on the model, a methodology for calculating initial shock wave of uncoupling charge has been given...According to the structure of explosive charge in rock blasting, a physical model has been set up in this paper. Based on the model, a methodology for calculating initial shock wave of uncoupling charge has been given. The pressure p3 has been calculated when high explosives act on granite, limestone, marble and shaIe respectively. Some important conclusions are also gained by the analysis of results.展开更多
Uncoupling protein 1 (UCP1) expressed by the brown adipose tissue (BAT) in the mitochondrial crista acts as a homeostatic thermogenerator of eutherians. The evaluation of UCP1 expression in the BAT offers significant ...Uncoupling protein 1 (UCP1) expressed by the brown adipose tissue (BAT) in the mitochondrial crista acts as a homeostatic thermogenerator of eutherians. The evaluation of UCP1 expression in the BAT offers significant scientific insight, especially in studies targeting limited areas such as the periarterial and pericardial regions of small experimental mammals. However, the negligible amount of this adipose tissue would render the general quantitative evaluation of the protein unreliable because of lipid contamination and low protein concentration. To address this problem, we quantitatively evaluated UCP1 expression in the mitochondrion of the mouse interscapular BAT using immunoelectron microscopy and immunohistochemical studies using a combination of primary and secondary antibodies in scheme A (rabbit anti-UCP1 IgG/gold particle-conjugated goat anti-rabbit IgG), B (rabbit IgG/gold particle-conjugated goat anti-rabbit IgG), C (rabbit anti-UCP1 IgG/gold particle-unconjugated goat anti-rabbit IgG), and D (rabbit IgG/gold particle-unconjugated goat anti-rabbit IgG). Scheme A shows the immunopositive reaction of obvious gold particles in the mitochondrial area, whereas other procedures revealed less distinctive reactions. The distinctive gold particle immunoreaction comprised electrical high-density spots with a mean diameter of >5 nm. However, in scheme B, the electrical high-density spots were scattered outside the mitochondrion and were significantly smaller than 4 nm;schemes C and D demonstrated few immunoreactions. Logistic regression analysis between schemes A and B showed that the threshold diameter of the electrical high-density spots measuring >5 nm indicated a true positive immunoreaction to anti-UCP1 antibody specifically in the mitochondrial area. Minor statistical difference was observed in the primary anti-UCP1 antibody between polyclonal IgG and monoclonal antibodies. Therefore, immunoelectron microscopy might be useful for evaluating negligible protein expression in some limited areas, such as UCP1 expression in the BAT of small experimental animals.展开更多
Objective To find out whether dexamethasone induces an uncoupling of the endothelial nitric oxide synthase （eNOS）. Methods ＆ Results A major cause of eNOS uncoupling is a deficiency of its cofactor tetrahydrobiopte...Objective To find out whether dexamethasone induces an uncoupling of the endothelial nitric oxide synthase （eNOS）. Methods ＆ Results A major cause of eNOS uncoupling is a deficiency of its cofactor tetrahydrobiopterin （BH4）. Treatment of human EA.hy 926 endothelial cells with dexamethasone decreased mRNA and protein expression of both BH4-synthesizing enzymes： GTP cyclobydrolase I and dihydrofolate reductase. Consistently, a concentration- and time-dependent reduction of BH4, dihydrobiopterin （BH2） as well as BH4：BH2 ratio was observed in dexamethasone-treated cells. Surprisingly, no evidence for eNOS uncoupling was found. We then analyzed the expression and phosphorylation of the eNOS enzyme. Dexamethasone treatment led to a down-regulation of eNOS protein and a reduction of eNOS phosphorylation at serine 1177. A reduction of eNOS expression may lead to a relatively normal BH4： eNOS molar ratio in dexamethasone-treated cells. Because the BH4-eNOS stoichiometry rather than the absolute BH4 amount is the key determinant of eNOS functionality （i.e., coupled or uncoupled）, the down-regulation of eNOS may represent an explanation for the absence of eNOS uncoupling. Phosphorylation of eNOS at serine 1177 is needed for both the NO-producing activity of the coupled eNOS and the superoxide-producing activity of the uncoupled eNOS. Thus, a reduction of serine 1177 phosphorylation may render a potentially uncoupled eNOS hardly detectable. Conclusions Although dexamethasone reduces BH4 levels in endothelial cells, eNOS uncoupling is not evident. The reduction of NO production in dexamethasone-treated endothelial cells is mainly attributable to reduced eNOS expression and decreased eNOS phosphorylation at serine 1177.展开更多
基金financial support by the Fundamental Research Funds for the Central Universities(xjh012019019)the National Natural Science Foundation of China(51606087)。
文摘In the chemical looping with oxygen uncoupling(CLOU)process,CuO is a promising material due to the high oxygen carrier capacity and exothermic reaction in fuel reactor but limited by the low melting point.The combustion rate of carbon is faster than the decoupling rate of oxygen carrier(OC).Hence,high temperature tolerance and rapid oxygen release rate of CuO modified by three different ores were investigated in this study.The kinetics analysis of oxygen decoupling with Cu-based oxygen carriers was also evaluated.Results showed that CuO modified by chrysolite had faster oxygen release rate than that of CuO.Limestone showed obvious positive effect on the oxidization process.The selected OCs could keep stable in at least 20 cycles,for about 1200 min.Shrinking core model(SCM)fitted well for the decoupling process in the temperature range of 1123-1223 K.Reduction rate kinetic information may aid in the development of chemical looping with oxygen uncoupling(CLOU)technologies during reactor design and process modeling.Ternary doped copper oxide with chrysolite and limestone could improve the reactivity of CuO in decoupling and coupling process and also improve the high temperature tolerance.
基金Supported by the Nanjing Health Science and Technology Development Fund,No.YKK24223.
文摘BACKGROUND Uncoupling protein 1(UCP1)plays a pivotal role in modulating energy expen-diture and maintaining metabolic homeostasis within brown and beige adipo-cytes.It has also been implicated in tumorigenesis.AIM To investigate the expression and function of UCP1 in gastric cancer(GC).METHODS UCP1 protein expression in 211 GC tissues was examined using immunohisto-chemistry.Bisulfite sequencing PCR(BSP)was used to detect the methylation status of the UCP1 promoter in GC cell lines and tissues.The relationship between UCP1 expression and clinicopathological parameters was analyzed.CCK8,scratch,transwell,and flow cytometry assays were carried out to analyze the proliferation,migration,invasion,and apoptosis of GC cell lines after knockdown or overexpression of UCP1 in vitro.A nude mouse tumor xenograft model was used to investigate the function of UCP1 in vivo.RNA sequencing,Kyoto Ency-clopedia of Genes and Genomes analysis,and Rap1 pull-down assays were performed to identify the pathway associated with UCP1.RESULTS Loss of UCP1 was significantly associated with gender,poor differentiation,and advanced TNM stage of GC.Hypermethylation of UCP1 was confirmed in GC cells and tumor tissues by BSP.Overexpression of UCP1 suppressed GC cell proliferation,migration,and invasion,and it promoted apoptosis in vitro.UCP1 overexpression also suppressed GC tumor growth in vivo.Moreover,overexpression of UCP1 in GC cells resulted in a significant decrease in active Rap1 protein levels,whereas downregulation of UCP1 markedly enhanced Rap1 activity.CONCLUSION UCP1 downregulation in GC through promoter hypermethylation is related to the progression of GC,indicating that UCP1 plays a role as a tumor suppressor in GC.It regulates Rap1 signaling and may be a potential therapeutic target in GC.
基金Supported by grants from Associazione Italiana Ricerca Cancro,Milan,ItalyFondazione Cari Pa Ro,Padova,ItalyMinistero dell’Istruzione,dell’Universitàe della Ricerca,Rome,Italy
文摘Overall 5-years survival of pancreatic cancer patients is nearly 5%,making this cancer type one of the most lethal neoplasia.Furthermore,the incidence rate of pancreatic cancer has a growing trend that determines a constant increase in the number of deceases caused by this pathology.The poor prognosis of pancreatic cancer is mainly caused by delayed diagnosis,early metastasis of tumor,and resistance to almost all tested cytotoxic drugs.In this respect,the identification of novel potential targets for new and efficient therapies should be strongly encouraged in order to improve the clinical management of pancreatic cancer.Some studies have shown that the mitochondrial uncoupling protein 2(UCP2) is over-expressed in pancreatic cancer as compared to adjacent normal tissues.In addition,recent discoveries established a key role of UCP2 in protecting cancer cells from an excessive production of mitochondrial superoxide ions and in the promotion of cancer cell metabolic reprogramming,including aerobic glycolysis stimulation,promotion of cancer progression.These observations together with the demonstration that UCP2 repression can synergize with standard chemotherapy to inhibit pancreatic cancer cell growth provide the molecular rationale to consider UCP2 as a potential therapeutic target for pancreatic cancer.In this editorial,recent advances describing the relationship between cancer development and mitochondrial UCP2 activity are critically provided.
基金The item is supported by the National Nature Science Foundation(No.39970923)
文摘Objective:To explore the effects of acupuncture on the expression of uncoupling protein 1（UCP1）gene of brown adipose tissue （BAT）in obese rats.Methods:The expression of UCP1gene ofBAT was determined with RT-PCR technique.The changes of body weight,Lee’s index,body fat,andthe expression of UCP1gene of BAT in obese rats were observed before and after acupuncture.Results:The body weight,Lee’s indeX,body fat in obese rats were all markedly higher than those in normal rats,but the expression of UCP1gene of BAT in obese rats was all lower than that in normal rats.There werenegative correlation between the Obesity index and the expression of UCP1gent in BAT.After acupunc-ture the marked effect of weight loss was achieved while the expression of UCP1gene of BAT Obviously in-creased in obese rats.Conclusion:The abnormal reduction for expression of UCP1gene of BAT might bean important cause for the obesity.To promote the expression of UCP1in obese organism might be an im-portant cellular and mole
文摘Reactive oxygen species（ROS） are free radicals thought to mediate the neurotoxic effects of several neurodegenerative disorders.In the central nervous system,ROS can also trigger a phenotypic switch in both astrocytes and microglia that further aggravates neurodegeneration,termed reactive gliosis.Negative regulators of ROS,such as mitochondrial uncoupling protein 2（UCP2） are neuroprotective factors that decrease neuron loss in models of stroke,epilepsy,and parkinsonism.However,it is unclear whether UCP2 acts purely to prevent ROS production,or also to prevent gliosis.In this review article,we discuss published evidence supporting the hypothesis that UCP2 is a neuroprotective factor both through its direct effects in decreasing mitochondrial ROS and through its effects in astrocytes and microglia.A major effect of UCP2 activation in glia is a change in the spectrum of secreted cytokines towards a more anti-inflammatory spectrum.There are multiple mechanisms that can control the level or activity of UCP2,including a variety of metabolites and micro RNAs.Understanding these mechanisms will be key to exploitingthe protective effects of UCP2 in therapies for multiple neurodegenerative conditions.
基金a grant from National Natural Sciences Foundation of China (No. 30571764).
文摘The effect of target-directed regulation of the uncoupling protein-2 （UCP-2） gene expression on the ischemia-reperfusion injury of hepatocytes under different conditions was investigated. The expression plasmid and RNAi plasmid targeting UCP-2 gene were constructed and trans- fected into normal hepatocytes and fatty liver cells, respectively. The expression of UCP-2 mRNA was detected by real time PCR. The cells were divided into normal cell group （NCG）, group of normal cells transfected with empty vector （EVNCG）, group of normal cells transfected with expression plasmid （EPNCG）, fatty liver cell group （FCG） and group of fatty liver cells transfected with RNAi plasmid （RPFCG）. The ischemia-reperfusion model in vitro was established. One, 6, 12 and 24 h after reperfusion, Annexin V/PI flow cytometry was used to measure cell necrosis rate, apoptosis rate and survival rate. Simultaneously, the intracellular ATP, ROS and MDA levels were determined. The re- sults showed that 1, 6, 12 and 24 h after ischemia-reperfusion, the intracellular ROS, MDA and ATP levels and cell survival rate in EPNCG were significantly lower, and cell necrosis rate significantly higher than in NCG and EVNCG, but there was no significant difference in apoptosis rate among NCG, EVNCG and EPNCG （P〉005）. Six, 12 and 24 h after reperfusion there was no significant dif- ference in ROS, MDA levels and apoptosis rate between FCG and RPFCG （P〉0.05）, but the ATP level and survival rate of cells in RPFCG were higher than in FCG （P〈0.05）. It was concluded that down-regulation of the UCP-2 gene expression in steatotic hepatocytes could alleviate the ische- mia-reperfusion injury of liver cells.
基金Supported by the National Natural Science Foundation of China(No.81100665 No.81770929)
文摘AIM: To analyze the expression of uncoupling protein 2(UCP2) in retinal pigment epithelium(RPE) cells at the different human age, further explore the possible new target of RPE cells protection.METHODS: Adult retinal pigment epithelial-19(ARPE-19) cells and the primary RPE cells at the different age(9-20 y,50-55 y, 60-70 y, >70 y) were cultured and harvested. The expression of UCP2 in these cells was detected by reverse transcription-polymerase chain reaction(RT-PCR), Western blot and confocal microscopy.RESULTS: Cells from the donors more than 60 y are larger and more fibroblastic in appearance compared to ARPE-19 cells and those primary cultures obtained from the younger individuals by using phase-contrast micrographs. Results of RT-PCR, Western blot and confocal microscopy all showed that UCP2 was highly expressed in ARPE-19 cells and in the younger primary cultured human RPE cells at the age of 9-20 y and 50-55 y, whereas lower expression of UCP2 was measured in the older primary cultured human RPE cells at the age more than 60 y.CONCLUSION: Expression of UCP2 gene is decreased in aged RPE cells, promoting the lower ability of anti-oxidation in these cells. It is indicated that UCP2 gene might be a new target for protecting the cells from oxidative stress damage.
基金Supported by Grant from the National Natural Science Foundation of China,No. 30771039
文摘AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,which serve as a model for enteroendocrine L-cells,by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid.Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling.NCI-H716 cells were transiently transfected with a small interfering RNA(siRNA) that targets UCP2(siUCP2) or with a nonspecific siRNA using Lipofectamine 2000.The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.RESULTS:Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells.NCI-H716 cells that secreted GLP-1 also expressed UCP2.Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid(the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells,P < 0.05).In an experiment to determine dose dependence,stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium;10 mmol oleic acid diminished the release of GLP-1.Furthermore,GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%,as compared with NCI-H716 cells that were transfected with a non-specific siRNA(P < 0.01).CONCLUSION:UCP2 affected GLP-1 secretion induced by oleic acid.UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.
基金supported by a grant from the Bundesminis-terium für Bildung und Forschung (01ZX1903A)。
文摘Background: Pancreatic ductal adenocarcinoma(PDAC) is a disease of the elderly mostly because its development from preneoplastic lesions depends on the accumulation of gene mutations and epigenetic alterations over time. How aging of non-cancerous tissues of the host affects tumor progression, however, remains largely unknown. Methods: We took advantage of a model of accelerated aging, uncoupling protein 2-deficient( Ucp2 knockout, Ucp2 KO) mice, to investigate the growth of orthotopically transplanted Ucp2 wild-type(WT) PDAC cells(cell lines Panc02 and 6606PDA) in vivo and to study strain-dependent differences of the PDAC microenvironment. Results: Measurements of tumor weights and quantification of proliferating cells indicated a significant growth advantage of Panc02 and 6606PDA cells in WT mice compared to Ucp2 KO mice. In tumors in the knockout strain, higher levels of interferon-γ m RNA despite similar numbers of tumor-infiltrating T cells were observed. 6606PDA cells triggered a stronger stromal reaction in Ucp2 KO mice than in WT animals. Accordingly, pancreatic stellate cells from Ucp2 KO mice proliferated at a higher rate than cells of the WT strain when they were incubated with conditioned media from PDAC cells. Conclusions: Ucp2 modulates PDAC microenvironment in a way that favors tumor progression and implicates an altered stromal response as one of the underlying mechanisms.
基金The research has received funding from the National Natural Science Foundation of China(51976102)the National Key Research and Development Plan of China(2016YFB0600802-A and No.2017YFE0112500).
文摘Oxygen uncoupling characteristics of a natural manganese ore and a perovskitetype oxide CaMn_(0.5)Ti0_(37)5Fe_(0.125)O_(3)were studied by using a microfluidized bed thermogravimetric analysis(MFBTGA)technology which is based on a realtime mass measurement of fluidizing particles inside a bubbling bed reactor.The chemical stability,kinetics of the oxygen release and uptake reactions and fluidization property were investigated and the experimental data measured by MFBTGA were compared with the results in a regular TGA instrument(TGA Q500).The regular TGA Q500 results show the reactivity of both the manganese ore and perovskite oxide are stable for multi cycles,and the oxygen uncoupling capacity of the manganese ore is~1.2%(mass)which is~2 times higher than that of the perovskite oxide.However,the experimental results from the MFBTGA indicated that there is a serious agglomeration for the manganese ore.A very important finding is that the reaction rate of oxygen release and oxygen uptake of the perovskite oxide measured by the MFBTGA are~2 and~4 times faster than that of testedby the TGA Q500.We can conclude that MFBTGA is a very useful tool to measure the reactivity stability and kinetics of oxygen carriers in highthroughput analysis instead of the regular TGA.
基金supported by a grant from the Bundesministerium für Bildung und Forschung(0315892A,GERONTOSYS program)
文摘BACKGROUND： Uncoupling protein 2 （UCP2） has been suggested to inhibit mitochondrial production of reactive oxygen species （ROS） by decreasing the mitochondrial membrane potential. Experimental acute pancreatitis is associated with increased UCP2 expression, whereas UCP2 deficiency retards regeneration of aged mice from acute pancreatitis. Here, we have addressed biological and molecular functions of UCP2 in pancreatic stellate cells （PSCs）, which are involved in pancreatic wound repair and fibrogenesis. METHODS： PSCs were isolated from 12 months old （aged） UCP2^-/- mice and animals of the wild-type （WT） strain C57BL/6. Proliferation and cell death were assessed by em- ploying trypan blue staining and a 5-bromo-2＇-deoxyuridine incorporation assay. Intracellular fat droplets were visualized by oil red O staining. Levels of mRNA were determined by RT-PCR, while protein expression was analyzed by immunoblotting and immunofluorescence analysis. Intracellular ROS levels were measured with 2＇,7＇-dichlorofluorescin diacetate. Expression of senescence-associated β-galactosidase （SA β-Gal） was used as a surrogate marker of cellular senescence. RESULTS： PSCs derived from UCP2^-/- mice proliferated at a lower rate than cells from WT mice. In agreement with this observation, the UCP2 inhibitor genipin displayed dose- dependent inhibitory effects on WT PSC growth. Interestingly, ROS levels in PSCs did not differ between the two strains, and PSCs derived from UCP2^-/- mice did not senesce faster than those from corresponding WT cells. PSCs from UCP2^-/- mice and WT animals were also indistinguishable with respect to the activation-dependent loss of intracellular fat droplets, expression of the activation marker α-smooth muscle actin, type I collagen and the autocrine/paracrine mediators interleukin-6 and transforming growth factor-I~ 1. CONCLUSIONS： A reduced proliferative capacity of PSC from aged UCP2^-/- mice may contribute to the retarded regeneration after acute pancreatitis. Apart from their slower growth, PSC of UCP2^-/- mice displayed no functional abnormalities. The antifibrotic potential of UCP2 inhibitors deserves further attention.
文摘Objective: Determine the role of uncoupling protein 2 (UCP2) in the myocardial apoptosis of diabetic mellitus(DM). Methods: DM animal models were induced by streptozotocinon (STZ) on UCP2 knock-out mice (UCP2KO) and wild-type mice (WT), which were reared for 7 and 28 days after successful modeling, respectively. The expressions of relative protein for myocardial apoptosis, pro-caspase-9, were investigated using western blot. However, the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) was used to explain apoptosis at the DNA level. Results: Image analysis showed that the expression of pro-caspase-9 protein levels increased slightly in UCP-/- + DM-7-day group comparing with DM-7-day group (P > 0.05). The expression of pro-caspase-9 protein levels increased significantly (P < 0.05)in UCP-/- + DM-28-day group comparing with DM-28-day group. TUNEL analysis indicated that UCP2 reduced the number of apoptotic myocytes in the DM-28-day group by 70% in comparison to DM-7-day group by 30% (P < 0.05). Conclusion UCP2 may be one of the most important factors that contribute to the myocardial apoptosis of DM.
文摘According to the structure of explosive charge in rock blasting, a physical model has been set up in this paper. Based on the model, a methodology for calculating initial shock wave of uncoupling charge has been given. The pressure p3 has been calculated when high explosives act on granite, limestone, marble and shaIe respectively. Some important conclusions are also gained by the analysis of results.
文摘Uncoupling protein 1 (UCP1) expressed by the brown adipose tissue (BAT) in the mitochondrial crista acts as a homeostatic thermogenerator of eutherians. The evaluation of UCP1 expression in the BAT offers significant scientific insight, especially in studies targeting limited areas such as the periarterial and pericardial regions of small experimental mammals. However, the negligible amount of this adipose tissue would render the general quantitative evaluation of the protein unreliable because of lipid contamination and low protein concentration. To address this problem, we quantitatively evaluated UCP1 expression in the mitochondrion of the mouse interscapular BAT using immunoelectron microscopy and immunohistochemical studies using a combination of primary and secondary antibodies in scheme A (rabbit anti-UCP1 IgG/gold particle-conjugated goat anti-rabbit IgG), B (rabbit IgG/gold particle-conjugated goat anti-rabbit IgG), C (rabbit anti-UCP1 IgG/gold particle-unconjugated goat anti-rabbit IgG), and D (rabbit IgG/gold particle-unconjugated goat anti-rabbit IgG). Scheme A shows the immunopositive reaction of obvious gold particles in the mitochondrial area, whereas other procedures revealed less distinctive reactions. The distinctive gold particle immunoreaction comprised electrical high-density spots with a mean diameter of >5 nm. However, in scheme B, the electrical high-density spots were scattered outside the mitochondrion and were significantly smaller than 4 nm;schemes C and D demonstrated few immunoreactions. Logistic regression analysis between schemes A and B showed that the threshold diameter of the electrical high-density spots measuring >5 nm indicated a true positive immunoreaction to anti-UCP1 antibody specifically in the mitochondrial area. Minor statistical difference was observed in the primary anti-UCP1 antibody between polyclonal IgG and monoclonal antibodies. Therefore, immunoelectron microscopy might be useful for evaluating negligible protein expression in some limited areas, such as UCP1 expression in the BAT of small experimental animals.
文摘Objective To find out whether dexamethasone induces an uncoupling of the endothelial nitric oxide synthase （eNOS）. Methods ＆ Results A major cause of eNOS uncoupling is a deficiency of its cofactor tetrahydrobiopterin （BH4）. Treatment of human EA.hy 926 endothelial cells with dexamethasone decreased mRNA and protein expression of both BH4-synthesizing enzymes： GTP cyclobydrolase I and dihydrofolate reductase. Consistently, a concentration- and time-dependent reduction of BH4, dihydrobiopterin （BH2） as well as BH4：BH2 ratio was observed in dexamethasone-treated cells. Surprisingly, no evidence for eNOS uncoupling was found. We then analyzed the expression and phosphorylation of the eNOS enzyme. Dexamethasone treatment led to a down-regulation of eNOS protein and a reduction of eNOS phosphorylation at serine 1177. A reduction of eNOS expression may lead to a relatively normal BH4： eNOS molar ratio in dexamethasone-treated cells. Because the BH4-eNOS stoichiometry rather than the absolute BH4 amount is the key determinant of eNOS functionality （i.e., coupled or uncoupled）, the down-regulation of eNOS may represent an explanation for the absence of eNOS uncoupling. Phosphorylation of eNOS at serine 1177 is needed for both the NO-producing activity of the coupled eNOS and the superoxide-producing activity of the uncoupled eNOS. Thus, a reduction of serine 1177 phosphorylation may render a potentially uncoupled eNOS hardly detectable. Conclusions Although dexamethasone reduces BH4 levels in endothelial cells, eNOS uncoupling is not evident. The reduction of NO production in dexamethasone-treated endothelial cells is mainly attributable to reduced eNOS expression and decreased eNOS phosphorylation at serine 1177.
