Uncoupling protein 2 deficiency of non-cancerous tissues inhibits the progression of pancreatic cancer in mice

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.

VEGFR2、miR-21、UCP1及UCP3在非小细胞肺癌组织中表达及与其预后的相关性分析

目的分析血管内皮细胞生长因子受体2(VEGFR2)、微小RNA-21(miR-21)、解偶联蛋白1(UCP1)、解偶联蛋白3(UCP3)在非小细胞肺癌(NSCLC)组织内的表达及与其预后的相关性。方法选取98例NSCLC患者,术中取其癌组织与癌旁正常组织,检测VEGFR2、miR-21、UCP1及UCP3表达;分析VEGFR2、miR-21、UCP1及UCP3表达与其临床病理特征的关系;随访1年,分析VEGFR2、miR-21、UCP1及UCP3表达与患者生存率的关系。结果癌组织内的VEGFR2、UCP1阳性表达率及miR-21相对表达量高于癌旁正常组织,UCP3阳性表达率低于癌旁正常组织,差异有统计学意义(P<0.05);VEGFR2、miR-21、UCP1及UCP3表达与淋巴结转移、临床分期、分化程度有关(P<0.05);VEGFR2、UCP1阳性表达及miR-21高表达患者的1年生存率分别低于VEGFR2、UCP1阴性表达及miR-21低表达患者,UCP3阳性表达患者的1年生存率高于UCP3阴性表达者,差异有统计学意义(P<0.05)。结论VEGFR2、miR-21、UCP1及UCP3在NSCLC癌组织内呈异常表达,与患者的预后具有紧密联系。

Mitochondrial uncoupling protein 2 expression in colon cancer and its clinical significance

AIM: To detect the expression of mitochondrial uncoupling protein 2 (UCP2) in colon cancer and analyze the relation between UCP2 expression and clinical pathological features of colon cancer.METHODS: Fifteen colon tissue samples and 15 its adjacent tissue samples were obtained from colon cancer patients during surgical interventions. UCP2 expression was detected with immunohistochemical method in 10 normal controls, 10 hyperplastic polyp patients, 20 tubular adenoma patients and 78 colon cancer patients. Patients with rectal cancer were excluded. Quantitative reverse transcription polymerase chain reaction and Western blotting were used to detect UCP2 expressions in colon cancer tissue samples and its adjacent tissue samples. Relation between UCP2 expression and clinical pathological features of colon cancer was also analyzed. RESULTS: The UCP2 mRNA expression level was fourfold higher in colon cancer tissue samples than in its adjacent tissue samples. The UCP2 protein expression level was three-fold higher in colon cancer tissue samples than in its adjacent normal tissue samples. The UCP2 was mainly expressed in cytoplasm. The UCP2 was not expressed in normal colon mucosa. Strong positive staining for UCP2 with a diffuse distribution pattern was identified throughout the mucosa in colon cancer tissue samples with a positive expression rate of 85.9%. The UCP2 expression level was higher in colon cancer tissue samples at clinical stages Ⅲ and Ⅳ than in those at stageⅠ+ Ⅱ. Univariate analysis showed that the high UCP2 expression level was significantly correlated to colon cancer metastasis (hazard ratio = 4.321, confidence interval = 0.035-0.682, P = 0.046). CONCLUSION: UCP2 is highly expressed in human colon cancer tissue and may be involved in colon cancer metastasis.

Mitochondrial uncoupling protein 2 and pancreatic cancer:A new potential target therapy

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.

Uncoupling protein 2 in the glial response to stress:implications for neuroprotection

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.

Effect of Acupuncture on Uncoupling Protein 1 Gene Expression for Brown Adipose Tissue of Obese Rats

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

Effect of Target-directed Regulation of Uncoupling Protein-2 Gene Expression on Ischemia-reperfusion Injury of Hepatocytes

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.

UCP3对民猪前脂肪细胞产热相关基因表达的影响

为了探究解偶联蛋白3(UCP3)在民猪不同组织中的表达情况以及对民猪前脂肪细胞中线粒体相关基因和ATP合成酶相关基因表达的影响,采集1月龄民猪的背部脂肪组织作为研究材料,通过酶消化法分离前脂肪细胞进行体外培养,同时采集腋下脂肪、胸部脂肪、背部脂肪、腹股沟脂肪、肾周脂肪和肌内脂肪构建组织表达谱。通过体外转染UCP3基因的过表达载体或干扰片段的方法,采用实时荧光定量PCR技术检测MCU家族基因(MCU、MICU1、MICU2)、ATP合成酶(ATP5B、ATP5E)和1,4,5-三磷酸肌醇受体1型基因(ITPR1)的表达情况以及不同脂肪组织中UCP3基因的表达情况。结果显示:采用酶消化法可以在背部脂肪组织中快速获得足量的前脂肪细胞,细胞边缘折光性良好,边界清晰,形态与成纤维细胞相似。UCP3基因在不同脂肪组织中均有表达,在背部脂肪组织中表达量最高,在腹股沟脂肪中表达量最低。过表达UCP3基因后,MCU家族基因和ITPR1基因表达水平显著升高,ATP5B基因表达水平显著下降。干扰UCP3基因后,MCU家族基因和ITPR1基因表达水平显著降低,ATP合成酶基因表达水平显著升高。结果说明:UCP3基因在不同脂肪组织中存在表达差异,可促进MCU家族基因和ITPR1基因表达、抑制ATP5B基因表达。

Uncoupling protein 2 regulates glucagon-like peptide-1 secretion in L-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.

Decreased uncoupling protein 2 expression in aging retinal pigment epithelial cells

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.

Uncoupling protein 2 deficiency reduces proliferative capacity of murine pancreatic stellate cells

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.

β-石竹烯通过上调PPARγ/PGC-1α/UCP1通路促进肥胖小鼠白色脂肪棕色化作用

目的探究β-石竹烯(BCP)对肥胖小鼠白色脂肪棕色化的作用及其机制。方法雄性昆明小鼠高脂饮食辅以丙硫氧嘧啶生理盐水溶液[14.4 mg/(kg·d)]腹腔注射建立肥胖小鼠模型。肥胖模型小鼠随机分为模型组(Model组)和BCP给药组(BCP-50组),正常饮食小鼠设为对照组(Control组),每组8只。BCP给药组按50 mg/kg早晚灌胃给药各一次,其余组用吐温80水溶液灌胃,持续4周。4周给药结束后进行口服糖耐量实验,实验结束禁食过夜后处死小鼠,快速收集血液样本和脂肪组织用于后续实验检测。试剂盒检测血清学相关指标;苏木精-伊红染色观察脂肪组织形态;免疫组化染色观察脂肪组织解偶联蛋白1(UCP1)表达;Western blot检测附睾白色脂肪(eWAT)中过氧化物酶体增殖物激活受体γ共激活剂1-α(PGC-1α)、过氧化物酶体增殖物激活受体γ(PPARγ)、UCP1和大麻素受体2(CNR2)蛋白的表达。结果与Model组相比,BCP-50组肥胖小鼠的体质量显著减轻(P<0.05),摄食量减少(P<0.01),胰岛素抵抗得到改善(P<0.0001),肥胖小鼠血清中低密度脂蛋白胆固醇(LDL-C)和非酯化脂肪酸(NEFA)含量降低(P<0.0001和P<0.01),总胆固醇(TC)、三酰甘油(TG)和高密度脂蛋白胆固醇(HDL-C)含量无明显变化。此外,BCP-50组肥胖小鼠的脂肪系数和eWAT比重降低(P<0.05);eWAT和BAT中脂肪细胞减小,UCP1蛋白表达升高(P<0.01和P<0.05);除了UCP1外,BCP-50组肥胖小鼠eWAT中PGC1α、PPARγ和CNR2蛋白的表达水平也明显升高(P<0.01,P<0.05和P<0.001)。结论BCP通过上调PPARγ/PGC-1α/UCP1通路表达促进白色脂肪棕色化,从而改善肥胖。

Uncoupling protein 2 regulates myocardial apoptosis via the diabetogenic action of streptozotocin

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.

A Statistical Evaluation of Uncoupling Protein 1 in the Limited Area of Brown Adipose Tissue by Immunoelectron Microscopy

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.

大鼠脑线粒体UCPs活性改变对缺氧过程中氧化磷酸化效能的影响

目的:通过观察GDP对缺氧大鼠离体脑线粒体UCPs活性的影响,探讨UCPs活性改变在高原缺氧大鼠脑线粒体氧化磷酸化效能改变中的作用。方法:健康成年SD大鼠随机分为对照组、急性缺氧组和慢性缺氧组,分别于模拟海拔5000米高原环境连续缺氧暴露0d、3d和30d,分离脑线粒体,通过体外GDP干预后采用[3H]-GTP结合法测定UCPs的活性(以Scatchard作图法计算两者结合的解离常数Kd和最大结合量Bmax),采用Rhodamine123法和Clark氧电极法分别测定线粒体膜电位(MMP)和线粒体呼吸氧耗。结果:急、慢性缺氧使大鼠脑组织线粒体UCPs与[3H]-GTP的最大结合量(Bmax)均显著升高,而解离常数(Kd)、线粒体膜电位(MMP)和呼吸控制率(RCR)均显著降低,但解偶联呼吸氧耗增加。给予GDP干预后,各组UCPs的活性均被显著抑制,表现为Kd升高,Bmax降低;而MMP和RCR则升高,其中急性缺氧组的变化最显著。结论:模拟高原缺氧条件下GDP能通过抑制UCPs的活性提高大鼠脑线粒体呼吸活性和膜电位,提示UCPs的活性改变是高原缺氧条件下脑线粒体氧化磷酸化效率改变的原因之一。

血清UCP2水平对脓毒症诊断和预后评估的临床价值

目的探讨血清解偶联蛋白2(UCP2)水平对脓毒症的诊断价值和预后意义。方法选取2021年1月~2022年5月在四川省人民医院诊治的脓毒症患者104例(脓毒症组),根据28 d内预后情况将脓毒症患者分为存活组(n=68)与死亡组(n=36);另选取同期收治的局部感染患者100例作为对照组;检测患者入院24 h内血清UCP2、降钙素原(PCT)、C反应蛋白(CRP)、白细胞计数(WBC)、中性粒细胞(NEU)和血乳酸(Lac)等实验室指标;采用Spearman相关性检验对脓毒症患者血清UCP2水平与PCT水平进行相关性分析;采用多因素Logsitic回归模型分析各指标与脓毒症发生以及患者28 d预后的关系;并采用受试者工作特征(ROC)曲线评价各指标对脓毒症的诊断价值及预后预测价值。结果脓毒症组血清UCP2、PCT、CRP和Lac水平均显著高于对照组(P<0.05),两组WBC、NEU对比差异无统计学意义(P>0.05)。脓毒症患者血清UCP2水平与PCT水平呈正相关(r=0.351,P<0.05)。Logisitic回归分析显示,UCP2、PCT是脓毒症发生的独立危险因素(P<0.05),且是患者28 d死亡的独立危险因素(P<0.05)。ROC曲线分析显示,UCP2诊断脓毒症发生和预测患者28 d死亡的曲线下面积(AUC)分别为0.937、0.711。结论血清UCP2是脓毒症诊断的潜在标志物,其检测对于患者预后有预测意义。

无毛基因敲除小鼠PPARγ-PGC1α-UCP1信号通路蛋白的表达及棕色脂肪组织能量代谢状态的变化

目的:探讨无毛(Hr)基因缺陷对小鼠能量代谢的影响及机制。方法:雄性Hr基因敲除(Hr^(-/-))小鼠和同窝野生型(Hr^(+/+))小鼠各10只,记录小鼠从出生后10周内的体重;于第10周,使用代谢监测系统对小鼠的耗氧量、产热量、活动量以及24 h进食量和饮水量进行监测,测量肛温,ELISA法检测血清游离三碘甲状腺原氨酸(fT3)浓度,HE染色观察棕色脂肪组织(BAT),Western blot法检测BAT中过氧化物酶体增殖物激活受体γ(PPARγ)、PPARγ共激活因子1α(PGC1α)、解偶联蛋白1(UCP1)蛋白的表达。结果:出生后第1周至第10周,两组小鼠体重差异无统计学意义(P>0.05)。第10周,两组小鼠血清fT3浓度和活动量差异无统计学意义(P>0.05);与Hr^(+/+)小鼠比较,Hr^(-/-)小鼠的肛温、24 h进食量和饮水量、耗氧量和产热量升高(P<0.05),BAT内较多小空泡脂滴和较少大空泡脂滴,BAT中PPARγ、PGC1α、UCP1蛋白表达增加(P<0.05)。结论:Hr基因缺陷可能通过激活PPARγ-PGC1α-UCP1信号通路,调节BAT能量代谢,从而使小鼠处于高能量代谢和高体温状态。

银杏叶提取物通过UCP2/SIRT3通路改善大鼠脑缺血-再灌注损伤

目的:研究银杏叶提取物(EGb761)能否通过线粒体解偶联蛋白2(UCP2)/去乙酰化酶3(SIRT3)通路改善大鼠脑缺血再灌注(CIRI)损伤。方法:雄性SD大鼠分成以下四组:假手术组(sham)、脑缺血再灌注(CIRI)损伤组(CIRI)、银杏叶提取物组(EGb761)和UCP2抑制剂组(EGb761+Genipin)。对EGb761组和EGb761+Genipin组每天尾静脉注射10 mg/kg EGb761注射液,sham组和CIRI组给予尾静脉注射等剂量生理盐水,连续7 d;在第5~7 d,同时对EGb761+Genipin组每天灌胃50 mg/kg Genipin生理盐水溶液。末次给药次日,通过大脑左侧中动脉闭塞法(MCAO)构建大鼠脑CIRI模型。记录各组大鼠Longa神经功能评分和体重变化,取鼠脑制成石蜡切片,通过HE和尼氏染色并观察脑皮质损伤区病理变化;通过免疫组织化学技术检测脑皮质损伤区UCP2、SIRT3及天冬氨酸蛋白半胱氨酸酶3(caspase-3)的表达;收集动脉血,测定血清中总超氧化物歧化酶(SOD)活力和丙二醛(MDA)浓度。结果:与sham组比较,CIRI组大鼠神经功能评分上升(P<0.01),再灌注后体重减轻(P<0.01),脑组织病理损伤加重,UCP2、SIRT3表达减少,caspase-3表达增加(P<0.01),血清SOD活力下降,MDA浓度上升(P<0.01);与CIRI组比较,EGb761组大鼠神经功能评分下降(P<0.01),再灌注后体重增加(P<0.01),脑组织病理损伤减轻,UCP2、SIRT3表达增加,caspase-3表达减少(P<0.01),血清SOD活力增高,MDA浓度下降(P<0.01);与EGb761组比较,EGb761+Genipin组大鼠神经功能评分增加(P<0.05),再灌注后体重减轻(P<0.05),脑组织病理损伤较严重,UCP2、SIRT3表达减少,caspase-3表达增加(P<0.05),血清SOD活力下降,MDA浓度上升(P<0.01)。结论:EGb761可通过调控UCP2/SIRT3通路改善大鼠脑CIRI损伤。

Ginsenoside F1 administration promotes UCP1-dependent fat browning and ameliorates obesity-associated insulin resistance

Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.

高尿酸通过下调UCP2表达水平引起线粒体损伤的研究

目的在细胞水平探究高尿酸对线粒体解偶联蛋白2(UCP2)表达水平的影响,以探索高尿酸对HL7702细胞线粒体损伤作用的可能机制。方法通过实时荧光定量聚合酶链式反应(Q-PCR)和Western blot法分析3个不同浓度尿酸(400、800、1200μmol/L)对线粒体UCP2表达的影响,免疫荧光、荧光探针法等技术分析UCP2相关的线粒体损伤指标活性氧(ROS)、线粒体膜电位、三磷酸腺苷(ATP)合成的变化情况。结果与对照组相比,随着尿酸浓度的升高,3个浓度组(400、800、1200μmol/L)的线粒体UCP2 mRNA转录水平分别为对照组的46.30%、16.40%和5.00%(P<0.01),随着尿酸浓度的升高,线粒体UCP2蛋白表达也逐渐减少。ROS生成量随着尿酸浓度的升高呈现明显增加的趋势,3个浓度组(400、800、1200μmol/L)的ROS荧光强度分别为对照组的133、184和253倍(P<0.01),线粒体膜电位和ATP合成率与对照组比较则呈现明显降低趋势,3个浓度组(400、800、1200μmol/L)线粒体膜电位分别为对照组的14.53%、8.30%和4.70%(P<0.01),ATP合成率为对照组的83.45%、69.92%和55.64%(P<0.01)。结论随着尿酸浓度的增加,高尿酸对线粒体UCP2的mRNA和蛋白表达存在着抑制作用,并造成线粒体损伤。