解偶联蛋白及其基因多态性与能量代谢

解偶联蛋白（uncoupling proteins,UCPs）是线粒体内膜蛋白质, 目前已至少发现有5种（UCP1、UCP2、UCP3、UCP4和UCP5）,这个家族的蛋白质已经在人类、哺乳动物、禽类、鱼,甚至在植物的不同组织线粒体的内膜上被发现。UCPs 具有调节能量代谢, 促进脂肪酸的氧化作用,UCPs的基因多态性与脂肪代谢相关。     

解偶联蛋白mRNA研究进展

解偶联蛋白（UCPs）是机体组织特异表达的线粒体内膜蛋白质，有阻止肥胖的作用。UCPs有5种同族体，UCP1在啮齿类动物调节动物体重、维持体温有重要作用。UCP2主要存在于成年大型动物和人类，与糖尿病有关，UCP3主要存在于骨骼肌一啮齿类动物的棕色脂肪组织中，提供非颤抖的生热作用。UCP4是小鼠和非人类的灵长目动物大脑特有的线粒体UCPs同族体，可能与控制食欲有关。UCP5存在于人和小鼠的多 , 大脑和附睾特别丰富，受寒冷和绝食的影响，在UCPs转基因或基因敲出的实验动物可改善肥胖症，UCPs同族体受到多种因子调控。食物调节影响UCPs mRNA同族体在不同组织的特异表达。高等植物线粒体UCPs同族体PUMP、stUCP也有同样的解偶联作用。     

UCP基因在肉质方面的研究现状

解偶联蛋白（UCP）是机体组织特异表达的一种线粒体内膜蛋白质，它可以驱散质子电化学梯度，使呼吸链和ATP的合成解偶联，从而影响产热和能量代谢，进而影响肉质。目前已发现6种不同的家族成员，组成它们的氨基酸序列具有不同程度的同源性。本文综述了近年来UCPs在家禽及猪肉质方面的研究现状，为深入开展UCPs肉质方面的研究奠定基础。     

猪解耦联蛋白3(UCP3)基因的研究进展

解耦联蛋白(uncoupling protein,UCPs)是一类位于线粒体内膜的质子转运载体蛋白,它们参与机体的能量代谢,可将呼吸链与ATP的产生过程解耦联,使质子化学梯度消失,能量以产热形式散发,增加能量的消耗.目前,在哺乳动物中已发现的解耦联蛋白家族成员包括UCP1、UCP2、UCP3、UCP4、UCP5.在骨骼肌中分布最为广泛的成员为UCP3,研究显示,它可能是影响猪胴体和肉质性状的主效基因或与主效基因紧密连锁的标记基因[1].文章对猪解耦联蛋白3基因的研究进展进行了综述.     

猪UCP3基因的分离与多态分析

解偶联蛋白3是一种线粒体内膜上的转运蛋白,可以使氧化过程与ADP磷酸化过程解偶联。本研究分离了猪UCP3基因的外显子2~3和外显子6。经过序列分析,发现猪UCP3基因共有3处框移突变和18个SNP位点。在猪UCP3片段中分别包含一个SmaⅠ和SduⅠ酶切位点。UCP3片段SmaⅠ位点在大白×梅山F2家系中经PCR-RFLP分析,表现为AA、AB和BB 3种基因型,A基因频率为0.57,B基因频率为0.43。因此,可以将UCP3基因作为猪分子遗传育种的候选基因。     

解偶联蛋白与动物的冷适应

动物的脂肪组织为棕色脂肪组织(brow n ad ipose tissue,BAT)和白色脂肪组织(w h ite ad ipose tissue,W AT)。棕色脂肪组织中含有大量线粒体,是哺乳动物非颤抖产热的主要器官,对动物的体温控制和能量平衡调节起重要作用,位于线粒体内膜的解偶联蛋白(uncoup ling prote in,UCP)的含量和活性是决定其功能的关键因素。作者综述了UCP的结构、UCP基因的多态性及其与肥胖的关系、影响UCPmRNA表达的因素,并对UCP进行了讨论与展望。     

解偶联蛋白对动物能量代谢的作用

生物体内能量平衡问题始终是营养学研究的主要内容。已知影响生物体内能量平衡的因素很多,由解偶联蛋白(uncoupling proteins,UCPs)调控能量诱发脂肪组织和肌肉组织的生热作用是影响机体能量平衡的重要因素之一。本文综述了近年来UCPs的研究进展,着重论述了UCPs产热机制及其基因表达的影响因素,为深入开展UCPs能量代谢调控方面的研究奠定基础。     

牛UCP3基因多态性及其与血清生化指标的相关性研究

解耦联蛋白3(UCP3)是位于线粒体内膜的质子转运体,其在适应性产热、体重调节和能量代谢中发挥重要作用。本试验利用PCR-RFLP技术研究了鲁西牛、西门塔尔牛、摩拉水牛和尼里-拉菲水牛4个品种151头牛的UCP3基因的多态性及其与血清生化指标的相关性,为研究牛的能量代谢及耐热、耐寒性提供参考依据。结果表明:牛UCP3基因的第3外显子存在限制性内切酶BglⅠ多态。4个群体中的优势等位基因均为A,鲁西牛和西门塔尔牛的优势基因型均为AB型,在尼里水牛和摩拉水牛中AA基因型略占优势。在所研究的群体中,该多态基因座均处于Hardy-Weinberg平衡状态(P>0.05)。对遗传多态性与血清生化指标进行相关性分析后,发现鲁西牛的β球蛋白含量AA基因型个体显著高于AB型(P<0.05),尼里水牛的血清钾和α2球蛋白含量AA型个体显著高于AB型(P<0.05),水牛品种白蛋白含量和α2球蛋白含量与鲁西牛和西门塔尔牛差异显著,为进一步研究水牛与黄牛的差异提供了参考。     

牛UCP3基因多态性及其与血清生化指标的相关性研究

解耦联蛋白3(UCP3)是位于线粒体内膜的质子转运体,其在适应性产热、体重调节和能量代谢中发挥重要作用.本试验利用PCR-RFLP技术研究了鲁西牛、西门塔尔牛、摩拉水牛和尼里-拉菲水牛4个品种151头牛的UCP3基因的多态性及其与血清生化指标的相关性,为研究牛的能量代谢及耐热、耐寒性提供参考依据.结果表明:牛UCP3基因的第3外显子存在限制性内切酶BglⅠ多态.4个群体中的优势等位基因均为A,鲁西牛和西门塔尔牛的优势基因型均为AB型,在尼里水牛和摩拉水牛中AA基因型略占优势.在所研究的群体中,该多态基因座均处于Hardy-Weinberg平衡状态(P＞0.05).对遗传多态性与血清生化指标进行相关性分析后,发现鲁西牛的β球蛋白含量AA基因型个体显著高于AB型(P＜0.05),尼里水牛的血清钾和α2球蛋白含量AA型个体显著高于AB型(P＜0.05),水牛品种白蛋白含量和α2球蛋白含量与鲁西牛和西门塔尔牛差异显著,为进一步研究水牛与黄牛的差异提供了参考.     

绵羊褐色脂肪活性影响因素的研究进展

褐色脂肪细胞的结构和功能都与白色脂肪不同,其细胞富含线粒体,能够利用过剩的能量代谢底物进行产热,是幼龄哺乳动物非颤抖性产热的主要热量来源,在维持机体能量平衡方面具有重要作用。其产热过程由细胞线粒体内膜上的解偶联蛋白1(UCP1)介导,机体所处环境以及对激素的响应都可以影响褐色脂肪的活性。受到刺激后,褐色脂肪细胞表面的肾上腺素受体得到激活,激发细胞内的级联反应,同时使产热相关基因表达增强,增加能量消耗,减少脂肪沉积。褐色脂肪已经成为治疗肥胖以及能量代谢相关疾病的潜在靶点。鉴于褐色脂肪在脂肪沉积以及能量代谢方面的作用,关于畜禽褐色脂肪的研究也越来越深入。作者归纳了绵羊褐色脂肪的相关研究,主要包括影响绵羊褐色脂肪活性的环境因素如冷刺激、营养限制、长期缺氧和饲喂添加剂,以及激素因子(催乳素及其受体、甲状腺激素、瘦素、生殖激素),以期为绵羊产热脂肪的应用研究提供一定的理论依据。     

Association of single nucleotide polymorphism of chicken uncoupling protein gene with muscle and fatness traits

Uncoupling proteins (UCPs) are in the mitochondrial inner membrane and belong to the transporter family. The biological function of UCPs is regulating discharge of proton gradient generated by the respiratory chain. As a result, the production of ATP is diminished, and dissipative heat is yielded. The present study was designed to investigate the association of UCP gene with chicken growth and body composition traits. The ninth generation of the broiler lines divergently selected for abdominal fat was used as a research population. Primers for UCP gene were designed from chicken genomic sequence. A single-nucleotide polymorphism, in the exon3 (T1316C) of UCP gene was detected by the polymerase chain reaction and restriction fragment polymorphism (PCR-RFLP) method. The UCP polymorphism was associated with muscle and fatness traits, such as pectoralis minor weight and abdominal fat weight. The results indicated that UCP gene could be a candidate locus or linked to a major gene which affects muscle and fatness traits in chicken.     

Role of uncoupling protein 1 in the anti-obesity effect of beta3-adrenergic agonist in the dog

We have reported that chronic treatment with beta3-adrenoceptor agonists reduces body fat content and induces the expression of mitochondrial thermogenic uncoupling protein 1 (UCP1) in adipose tissue in the dog. To evaluate the role of UCP1 in the anti-obesity effect of the agonists, we isolated adipocytes from subcutaneous fat pad of beagles before and after a 2-week treatment with AJ-9677, a specific beta3-adrenoceptor agonist, and examined their thermogenic activity in vitro. Histological and protein analysis revealed that adipose tissues before the treatment were composed of unilocular cells filled with a single large droplet, while the tissues after the treatment contained many smaller and some multilocular adipocytes expressing UCP1 and abundant mitochondrial proteins. Before the treatment, oxygen consumption rate was very low and did not change even when the cells were stimulated by AJ-9677. Two-week AJ-9677 treatment increased basal oxygen consumption rate by 7-fold, and produced a clear responsiveness to AJ-9677 stimulation. Thus, chronic treatment with AJ-9677 induced UCP1 in adipocytes, where oxygen consumption increased in response to AJ-9677 stimulation. It was suggested that UCP1-dependent energy expenditure in adipose tissue contributes to the anti-obesity effect of beta3-adrenoceptor agonist in dogs.     

贵州地方猪种UCP3基因多态性与肉质性状的相关性分析

解耦联蛋白3(uncoupling protein 3,UCP3)是调节能量和脂肪代谢的重要因子。以商品猪(杂交猪)为对照,采用SSCP方法对贵州地方猪品种糯谷猪和萝卜猪的UCP3基因进行了多态性分析。结果表明:3个猪群体中,都检测到了3种基因型(AA、BB、AB),χ2独立性检验结果显示,3种基因型在3个群体间的分布不一致,糯谷猪和萝卜猪以AB基因型为主,杂交猪以BB基因型占优势,杂交猪与地方猪种之间的差异显著(P<0.01);对纯合基因型的UCP3基因片段进行克隆测序,证实AA基因型中UCP3基因外显子6编码区第842位碱基发生了单碱基突变(T→C),导致编码的氨基酸从苏氨酸突变为甲硫氨酸。进一步分析3种基因型与胴体和肉质性状之间的相关性,证明AB基因型个体的肉质最优,贵州地方猪种的大理石纹、肌内脂肪含量和嫩度3项指标显著优于商品猪(P<0.01),因此推测UCP3基因与贵州地方猪种的肉质性状具有相关性,可能是贵州地方猪种肉质性状的候选基因。     

Molecular and histological evidence of brown adipose tissue in adult cats

Brown adipose tissue (BAT) can influence glucose, lipid, and energy metabolism in rodents. Active BAT is now known to be present in adult humans, and interventions targeting BAT are being investigated for the treatment of human obesity and disorders of glucose and lipid metabolism. Domestic cats, like humans, are at increasing risk for obesity and diabetes but little is known about the presence and role of BAT in adult cats. The purpose of this study was to determine if brown adipocytes, identifiable by histological features and molecular markers, were present in the fat depots of adult cats. Adipose tissue samples from intrascapular, perirenal, and subcutaneous depots of eleven 8–12 year old cats (6 lean, 5 obese), were analyzed by real-time PCR for brown adipocyte markers uncoupling protein 1 (UCP1) and Type II iodothyronine 5′deiodinase (D2), by histological examination and by immunohistochemistry for UCP1.UCP1 mRNA was detectable in interscapular and subcutaneous depots in all cats, and in the perirenal depot in 10/11 cats. D2 mRNA was detectable in all depots from all cats. Multilocular adipocytes were identified in the interscapular depots of 4/11 cats and these were positive for UCP1 immunoreactivity. The results demonstrate that UCP1-expressing brown adipocytes are present in multiple depots of adult lean and long-term obese cats, even at 8–12 years of age. It is possible that dietary components or pharmacological agents that influence brown fat activity could exert a relevant biological effect in cats.     

MC4R基因研究进展

黑素皮质素受体-4(melanocortin-4 receptor,MC4R)是下丘脑腹内侧核分泌的一类肽类物质,为黑素皮质素受体家族5个亚型(MC1-5R)之一。在哺乳动物中,MC4R具有介导瘦蛋白(leptin)的功能,是一个调节能量平衡与能量动态平衡的重要信号分子,可与其内源性配体黑素皮质素激素(melanocortin,MC)或刺鼠色蛋白(agouti protein,agouti蛋白)和agouti相关蛋白(agouti related protein,AGRP)相结合,从而在控制食欲和体重稳态中起关键作用。因此,MC4R在人类肥胖研究中作为重要的调节因子倍受关注。最近有研究表明:MC4R的1232位点的G→A的突变与绵羊背膘厚度间存在关联,AG和AA型较GG型具有较高的背膘厚度。