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.

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.

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 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。

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.

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.

2型糖尿病合并非酒精性脂肪肝大鼠肝脏SIRT1、UCP2表达的变化

目的观察2型糖尿病(T2DM)合并非酒精性脂肪肝(NAFLD)大鼠肝脏沉默调节蛋白1(SIRT1)、线粒体脱偶连蛋白2(UCP2)表达的情况,探讨T2DM合并NAFLD的可能发病机制。方法雄性SD大鼠24只,随机分为正常对照组(NC组,12只)和T2DM合并NAFLD模型组(MC组,12只)。NC组喂以常规饲料,MC组喂以高脂高糖饲料。12周末隔夜空腹给予MC组大鼠腹腔注射链脲佐菌素(30 mg/kg)1次,破坏部分胰岛,NC组注射相应体积的柠檬酸缓冲液。14周末测定两组大鼠体质量、空腹血糖、谷丙转氨酶、谷草转氨酶、总胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白、极低密度脂蛋白、游离脂肪酸、空腹胰岛素、计算胰岛素抵抗指数,并观察肝脏组织的病理变化,免疫组化法及Real-time PCR法测定肝脏组织中SIRT1、UCP2的表达情况。结果 14周时MC组大鼠空腹血糖、谷丙转氨酶、谷草转氨酶、总胆固醇、甘油三酯、低密度脂蛋白、极低密度脂蛋白、游离脂肪酸、空腹胰岛素、计算胰岛素抵抗指数均较NC组大鼠升高(P<0.05),高密度脂蛋白较NC组减低(P<0.05)。病理组织学结果表明NC组大鼠肝组织结构完整,肝细胞排列紧密成肝索,细胞质丰富,细胞核圆形;MC组大鼠肝细胞高度气球样变,胞质中有大量脂滴空泡,肝组织均可见中至重度脂肪肝。在免疫组化和mRNA水平上表明,MC组肝脏SIRT1表达较NC组明显降低(P<0.05),而UCP2表达较NC组明显升高(P<0.05)。结论在T2DM合并NAFLD大鼠肝脏组织中SIRT1表达显著降低,UCP2表达显著升高。

加味二陈汤对非酒精性脂肪肝大鼠UCP2影响的动态观察

目的观察加味二陈汤对非酒精性脂肪肝大鼠UCP2的影响。方法 120只SD大鼠随机分为3组,正常组(50只)、模型组(50只)、加味二陈汤组(20只,以下简称二陈组。自第8周开始给药,持续4周)。分别于第4、6、8、10、12周观察各组大鼠各项指标:体重、肝湿重、血清肝功能(ALT)、血脂(血清TC、)、肝脂(肝TC)、肝组织石蜡切片(HE染色)、肝脏UCP2 mRNA(realtime-PCR)。结果 8、10、12周的肝脏病理切片的结果显示,高脂饮食导致大鼠出现了非酒精性脂肪肝(NAFLD),其程度逐渐加重。模型组肝体指数、ALT、血脂、肝脂、解偶联蛋白2(uncoupling protein 2,UCP2)mRNA均随时间延长逐渐增高,与正常组差异有统计学意义。12周末,加味二陈汤组的肝指数、血脂、肝脂、ALT和UCP2 mRNA均低于模型组。结论随着非酒精性脂肪肝的形成和程度加重,肝脏UCP2的表达逐渐增强,脂质代谢紊乱,发生过氧化反应,促使脂肪肝形成和发展。加味二陈汤可降低非酒精性脂肪肝大鼠的肝指数、血脂、肝脂、ALT和UCP2 mRNA,达到调节机体脂质代谢,改善脂肪肝症状的效果。说明从痰瘀着手,采用经典化痰方加味二陈汤治疗脂肪肝,其作用靶点之一可能是引起UCP2表达的下调。

SIRT1/UCP2通路在白藜芦醇抑制血管内皮细胞氧化应激损伤中的作用

目的观察白藜芦醇对血管内皮细胞氧化应激损伤的抑制作用,并围绕SIRT1/UCP2信号通路探讨其作用机制。方法原代培养人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs),用叔丁基过氧化氢(t-BHP)建立HUVECs氧化应激损伤模型。CCK-8法检测细胞增殖,确定半抑制浓度(IC50)。荧光分光光度计检测细胞内活性氧(ROS)生成。CCK-8法检测白藜芦醇对t-BHP诱导的HUVECs活力的影响;qRT-PCR法检测白藜芦醇对SIRT1和UCP2mRNA表达的影响;Western blot法检测白藜芦醇对SIRT1、UCP2和Caspase-3在细胞内蛋白表达的影响。结果 t-BHP明显抑制细胞活力,IC50为80μmol/L。白藜芦醇(0.1、1、10μmol/L)预处理2 h能显著抑制t-BHP诱导的细胞活力下降(P<0.05),并抑制t-BHP诱导的细胞内ROS增加(P<0.05)。同时,白藜芦醇能明显抑制t-BHP诱导的SIRT1的mRNA和蛋白表达下降、UCP2的mRNA和蛋白表达升高及Caspase-3表达增加(P<0.05),而Sirt1抑制剂尼克酰胺能削弱白藜芦醇的抑制作用。结论白藜芦醇可能通过活化SIRT1抑制UCP2表达,削弱t-BHP诱导的细胞内ROS生成,从而抑制血管内皮细胞氧化应激损伤。

成都地区肥胖人群UCP2基因多态性研究及其与肠道菌群关系的初探

目的研究成都地区单纯性肥胖和正常体质量成人解偶联蛋白2基因(UCP2)Ala55Val多态性,初步探讨UCP2基因Ala55Val不同基因型与肠道菌群关系。方法采用PCR-RFLP检测86例成都地区成人(单纯性肥胖组43例,正常体质量组43例)的UCP2基因ALa55Val多态性,并分别比较不同基因型间6种肠道菌群数量的差异。结果单纯性肥胖组和正常体质量组均存在UCP2基因Ala/Ala、Ala/Val、Val/Val多态,两者表型分布差异有统计学意义(χ2=11.97,P<0.05);单纯性肥胖组UCP2等位基因突变频率高于正常体质量组,差异有统计学意义(χ2=10.06,P<0.05);单纯性肥胖组、正常体质量组和研究总体中不同基因型人群的6种肠道菌群数量差异无统计学意义(P>0.05)。结论UCP2基因ALa55Val变异可能是成都地区人群单纯性肥胖的危险因素,但该基因ALa55Val变异与肥胖的关联可能与肠道菌群数量改变无关。

糖毒性下UCP2介导的胰岛功能紊乱的研究

目的研究不同浓度高糖对胰岛INS-1细胞解偶联蛋白2(UCP2)基因表达的影响,探讨UCP2基因与高糖刺激下氧化应激和胰岛素分泌之间的关系,进一步了解糖尿病糖毒性的发病机制。方法将不同浓度的葡萄糖作用于INS-1细胞,镜下观察INS-1细胞的形态改变,应用可见分光光度计测定丙二醛(MDA)含量,运用ELISA方法检测葡萄糖刺激的胰岛素分泌(GSIS),同时应用RT-PCR方法检测UCP2基因的表达。结果①随着糖浓度的增加,INS-1细胞的凋亡增多,MDA含量逐渐增加,GSIS值逐渐下降,不同糖浓度组比较,差异具有显著性意义(P<0.01)。②随着葡萄糖浓度增加,INS-1细胞UCP2 mRNA的表达总体逐渐增强。结论高糖可促进INS-1细胞凋亡,在高糖作用下活性氧物质(ROS)代谢产物MDA增多,通过激活UCP2的途径引起胰岛细胞胰岛素分泌功能受损。这可能也是糖毒性对胰岛β细胞损害的一个重要环节。

真鲷肝脏解偶联蛋白2 (UCP2)基因及其功能的探讨

从真鲷 (Pagrusmajor)肝脏通过简并引物PCR克隆解偶联蛋白 2 (UCP2 )cDNA部分序列。该片段长6 74bp ,编码 2 2 4个氨基酸残基。推测的此部分氨基酸序列包含线粒体载体蛋白的特征结构 ,并与其它脊椎动物UCP2氨基酸序列同源性在 72 8%以上。对变温动物鱼类UCP2组织表达调控研究表明 :与哺乳类UCP2基因不同 ,真鲷UCP2基因在肝脏大量表达 ,而在腹腔肠系膜脂肪组织则仅有痕迹量表达 ,两者表达水平相差 2 0倍以上。饲料中添加 10 %绿鳕油或 48h饥饿对真鲷肝脏UCP2基因的表达水平均无显著影响 ,表明UCP2基因在脂肪含量高的鱼类肝脏表达十分稳定 ,为维持其基本功能所必需。真鲷肝脏和腹腔肠系膜脂肪组织UCP2基因表达水平的强烈反差 ,与鱼类这两种贮脂器官完全不同的氧化活性相一致 [动物学报 49(1) :110～ 117,2 0 0 3]。

中国汉族2型糖尿病人群中UCP基因单核苷酸多态性与视网膜病变的关联分析

背景研究发现血糖水平的短期升高可对细胞和组织造成长期损害，这种损伤可能存在代谢记忆现象，合理管理血糖代谢记忆对糖尿病并发症的预防有重要作用，但其机制尚未完全阐明，推测糖尿病患者中糖尿病视网膜病变（DR）的发生可能与相关机制有关。解偶联蛋白（UCPs）可减少线粒体活性氧（ROS）的生成，可能与DR发病相关。目的探讨中国汉族2型糖尿病人群中DR与UCP基因单核苷酸多态性（SNPs）之间的关系。方法采用横断面研究方法和整群抽样法，于2014年11月至2015年1月在上海市新泾社区对1875例确诊为2型糖尿病的患者进行流行病调查，收集受检者的基本信息、眼科检查和血生物化学检验结果，采集每例患者的全血2ml以提取DNA。采用Sequenom平台将UCP1基因的8个SNPs位点、UCP2基因的3个SNPs位点及UCP3的7个SNPs位点选为标记位点以检测基因型，采用SAS和SHEsis软件计算Hardy—Weinberg平衡、碱基型和基因型频率，评估各位点SNPs与DR之间的关系。结果受检的1875例2型糖尿病患者中530例患DR，占28．27％。UCP2基因的rs660339位点和UCP3基因的rs1626521位点、rs668514位点的检出率低，UCP2基因rs632862位点次要等位碱基频率〈0．01，UCP3基因的rs15763位点不符合Hardy—Weinberg平衡，故均不纳入分析。在纳入分析的13个SNPs位点中，仅有UCP1基因的2个SNPs位点与DR发病有关，其中与非糖尿病视网膜病变（NDR）患者比较，DR患者rsl0011540的G碱基频率增加[P=0．03，OR=1．31，95％可信区间（CI）=1．03～1．67]，rs3811787的T碱基频率下降（P=0．04，OR=0．86，95％CI=0．75～0．99）。基因型分析发现，DR患者UCP1基因的rs3811790位点纯合子C／C和A／A频率明显多于NDR患者，杂合子C／A频率少于NDR患者，差异均有统计学意义（P〈0．01）。Logistic回归分析提示，在排除了血糖水平和糖尿病病程的影响因素后，rs10011540和rs3811787位点SNPs仍是DR发病的独立影响因素。结论中国汉族2型糖尿病患者UCP1基因rs10011540和rs3811787位点SNPs与DR发病相关。

有氧运动下调的脂肪肝小鼠肝脏UCP2表达对肝脏ATP含量及抗氧化功能的影响

目的研究有氧运动下调高脂膳食诱导的C57BL/6J脂肪肝小鼠肝脏UCP2对肝脏ATP含量及抗氧化功能的影响,进而探讨其与抗氧化酶在脂肪肝发病过程中的作用。方法以高脂膳食诱导的脂肪肝小鼠为模型,分析有氧运动20 w后肝脏UCP2及Mn-SOD表达、肝脏ATP的含量及MDA的变化。结果肝脏UCP2与Mn-SOD在高脂膳食组(HS组)均显著升高;恢复正常膳食结合有氧运动20 w组(RE组),Mn-SOD表达进一步升高,而UCP2表达显著降低。肝脏ATP含量在HS组显著降低,RE组明显得到恢复。HS组MDA含量显著升高,RE组明显得到恢复。结论(1)高脂膳食诱导的脂肪肝小鼠肝脏UCP2表达升高在保护肝脏免受氧化损伤方面作用有限;(2)有氧运动可下调高脂膳食诱导的脂肪肝肝脏线粒体UCP2表达,上调Mn-SOD活性及表达,从而减少线粒体能量损耗及活性氧的氧化损伤,保护肝脏免受活性氧和能量损耗导致的损伤。

2型糖尿病伴非酒精性脂肪性肝病大鼠肝脏UCP2的表达及意义

目的探讨持续高脂饲养加链脲佐霉素诱导2型糖尿病伴非酒精性脂肪性肝病(NAFLD)大鼠解偶联蛋白-2(UCP2)在肝脏中的表达及意义。方法 30只雄性SD大鼠随机分为正常对照组、NAFLD组及T2DM伴NAFLD组。分别给予正常饮食和持续高脂饮食喂养,于8、16周末T2DM伴NAFLD组加链脲佐霉素(STZ)30mg/kg腹腔注射。观察各组大鼠肝脏脂肪变性情况,用免疫组织化学染色观察肝脏UCP2蛋白表达,以半定量逆转录-聚合酶链反应(RT-PCR)检测肝脏UCP2 mRNA的表达,同步取血检测各组大鼠血糖、胰岛素、肝功能、血脂水平。结果随喂养时间延长NAFLD组及T2DM伴NAFLD组大鼠出现肝脏广泛水样变性和不同程度脂肪变性及血糖、胰岛素、肝酶、血脂水平升高,与正常对照组比较差异有统计学意义(P=0.002);NAFLD组及T2DM伴NAFLD组肝脏UCP2蛋白表达及mRNA表达均明显升高,与正常对照组比较差异有统计学意义(P<0.001);T2DM伴NAFLD组较单纯NAFLD组UCP2表达增加更为明显(P<0.001)。结论持续高脂喂养加小剂量STZ诱导的T2DM伴NAFLD组大鼠较单纯NAFLD组大鼠肝脏UCP2蛋白及mRNA表达增高显著,伴肝脏脂肪变性及炎症反应更严重,可能是T2DM伴NAFLD发生的因素之一。

迷走神经切除对大鼠胃内UCP_2 mRNA表达及胃酸分泌的影响

目的:观察整体大鼠胃酸分泌与ATP水平之间的关系及迷走神经对解偶联蛋白2(UCP2)mRNA表达的调节。方法:制备大鼠高选择性迷走神经切断模型。采用滴定法检测大鼠胃酸酸度,荧光测定法检测胃体组织内ATP含量,应用Northernblot法检测分析UCP2mRNA表达。结果:迷走神经切断后24h,大鼠胃酸酸度显著降低,胃体组织内ATP含量下降。与假手术组相比,胃体组织UCP2mRNA表达显著增加。结论:迷走神经切断后24h大鼠胃体组织ATP含量下降;迷走神经下调胃体组织UCP2mRNA表达。结果提示大鼠迷走神经可能通过抑制UCP2mRNA表达,提高ATP含量,为质子泵泌酸提供能量来源。

疏肝健脾方药对非酒精性脂肪性肝病大鼠肝组织UCP2 mRNA及蛋白表达的影响

目的观察疏肝健脾方药对非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)大鼠肝组织解偶联蛋白2(uncoupling protein 2,UCP2)mRNA及蛋白表达的影响,初步探讨疏肝健脾方药治疗NAFLD的作用机制。方法采用高脂饲料喂养12周复制雄性SD大鼠NAFLD模型,将模型大鼠分为疏肝组、健脾组、疏肝健脾综合组(综合组)、三七脂肝丸组(三七组)、模型组,各组给予相应治疗8周。测定各组大鼠血清总胆固醇、三酰甘油、低密度脂蛋白胆固醇和高密度脂蛋白胆固醇含量。采用RT-PCR方法检测肝组织UCP2 mRNA的表达,免疫组织化学方法检测肝组织中UCP2蛋白活性变化。结果与正常组比较,模型组大鼠肝组织中UCP2 mRNA表达水平显著升高(P<0.05);与模型组比较,疏肝组、健脾组和综合组UCP2 mRNA表达水平显著下降(P<0.05)。模型组肝组织UCP2蛋白表达水平显著升高;与模型组比较,各用药组UCP2蛋白表达水平均显著下调(P<0.01)。结论疏肝健脾方药可使NAFLD大鼠肝组织中UCP2基因和蛋白表达水平降低。