组学技术在山羊乳研究中的应用

山羊乳是一种含有丰富营养成分的生物学流体,也是全球乳源的重要组成部分。山羊乳生物分子结构和功能一直是研究的热点,组学技术可以对这些生物分子成分进行全面分析。对蛋白质组学、脂质组学和代谢组学在山羊乳研究中的应用进行了综述。     

代谢组学在奶牛营养与牛奶质量安全方面的研究进展

代谢组学是检测低分子质量(通常分子质量小于1 000u)代谢物的变化,并以此来研究生物体受到病理/生理刺激或基因改变后所产生代谢产物的构成及其变化规律的学科。它是后基因时代发展起来的一门新的学科,是系统生物学的重要组成部分。代谢组学已经广泛应用于生理学、病理学、药理学、动物营养学、动物学和植物学等各个领域,但代谢组学在奶牛营养与牛奶质量安全研究中的应用还比较少。本文从代谢组学的基本概念、研究思路和方法等入手,综述了目前代谢组学在奶牛营养、疾病、热应激、牛奶质量与奶品安全中的应用。     

植物多酚对动物脂质代谢影响的研究进展

脂肪组织是动物体内的重要组成部分,脂质代谢过程对动物生长性能以及畜禽屠宰后肉品质有重要影响。植物多酚作为一种天然的活性物质,可以通过调节肠道微生物多样性、激活能量感受器腺苷酸活化蛋白激酶(AMPK)、促进线粒体生物合成等途径发挥其对脂质代谢的调节作用。目前,利用植物多酚来调控动物脂质代谢,从而改善屠宰后肉品质的研究已逐步成为各领域的研究热点。本文根据国内外对植物多酚调控脂质代谢的研究现状,综述了植物多酚的功能作用对动物体内脂质代谢的影响,为提高畜禽屠宰后肉品质提供理论基础。     

镁的营养作用研究进展

镁是生物体内重要的阳离子,参与了体内所有的能量代谢,催化或激化300多种酶体系。本文综述了镁对动物体脂质过氧化、应激及脂类代谢等方面影响的研究近况,并探讨了其可能的作用机制。     

黄芩苷药代动力学的研究进展

药代动力学（Pharmacokinetics）是定量研究药物在生物体内吸收、分布、代谢和排泄规律，并运用数学原理和方法阐述血药浓度随时间变化的规律的一门学科，即研究给药后药物在体内的位置、数量、疗效与时间之间的关系。目前已成为生物制药、临床药学、药理学、分子药理学、毒理学、药剂学、病理学、生物化学等学科的基础。     

外泌体长链非编码RNA对脂代谢调控机制的研究进展

外泌体(exosomes)是一类由细胞分泌并且可远距离传递生物信息的纳米级胞外囊泡。它通过细胞分泌释放,在体液中传播,最后被其他细胞吞噬以达到传递生物信息的作用。脂类代谢一直是生命科学研究领域的热点,虽然影响脂质代谢的长链非编码RNA(lncRNA)很多,但外泌体中影响脂质代谢的lncRNA研究却相对较少。基于这个原因,对于外泌体源lncRNA的研究就十分必要。作为外泌体所携带的重要遗传物质之一,lncRNA是一类长度200 nt的RNA分子,行使着诸如转录激活、染色质修饰等许多重要的生物功能。文章介绍了外泌体源lncRNA的生物学特点,列举了外泌体源lncRNA通过不同的分子机制来直接或间接的对脂质代谢产生影响的实例,分析了外泌体源lncRNA由于表达异常所导致的脂类代谢疾病,并且举例说明了外泌体源lncRNA作为生物标记的原理,最后对外泌体源lncRNA可作为家畜脂肪沉积生物标记功能的前景做了展望。如果在未来的研究中有更多的外泌体源lncRNA被检出,并足够对脂类代谢异常情况进行标记的话,那么对于预测和调控家畜脂肪沉积无疑会产生积极的意义。     

外泌体长链非编码RNA对脂代谢调控机制的研究进展

外泌体（exosomes）是一类由细胞分泌并且可远距离传递生物信息的纳米级胞外囊泡。它通过细胞分泌释放，在体液中传播，最后被其他细胞吞噬以达到传递生物信息的作用。脂类代谢一直是生命科学研究领域的热点，虽然影响脂质代谢的长链非编码RNA（lncRNA）很多，但外泌体中影响脂质代谢的lncRNA研究却相对较少。基于这个原因，对于外泌体源lncRNA的研究就十分必要。作为外泌体所携带的重要遗传物质之一，lncRNA是一类长度 > 200 nt的RNA分子，行使着诸如转录激活、染色质修饰等许多重要的生物功能。文章介绍了外泌体源lncRNA的生物学特点，列举了外泌体源lncRNA通过不同的分子机制来直接或间接的对脂质代谢产生影响的实例，分析了外泌体源lncRNA由于表达异常所导致的脂类代谢疾病，并且举例说明了外泌体源lncRNA作为生物标记的原理，最后对外泌体源lncRNA可作为家畜脂肪沉积生物标记功能的前景做了展望。如果在未来的研究中有更多的外泌体源lncRNA被检出，并足够对脂类代谢异常情况进行标记的话，那么对于预测和调控家畜脂肪沉积无疑会产生积极的意义。     

脂质组学技术在家畜精液质量评价和体外保存研究中的应用研究进展

精液质量评价是公畜繁殖力评定的重要手段之一。随着组学技术的快速发展，研究人员可以获得精子细胞高通量的基因、转录本、蛋白和代谢物等信息，对于精液质量评价以及相关的辅助生殖技术研究具有重要意义。最近，研究人员尝试采用脂质组学技术探讨影响哺乳动物精子细胞受精能力的因素。脂质组学（lipidomics）主要是利用高通量技术研究细胞、组织或生物体内的脂类成分和分布等基本生物学特征，在对脂类进行精确定量的基础上，探讨脂类多样性与细胞代谢调控和相应生物学功能的关系。作为蛋白质和核酸的下游产物，脂类可以更直接地反映组织细胞的实时生理状态。精子细胞质膜富含各种脂类，这些脂类对精子细胞的结构和功能具有重要影响。此外，通过脂质组学研究可以获得一些潜在的标记物用于家畜精液质量评价。目前，脂质组学已经应用于精子细胞脂肪酸研究。然而，虽然脂质组学研究发展迅速，但该方法仍存在一定的局限性，主要表现为样品脂类提取技术流程没有统一标准，导致对同一个结果产生不同的解释，因此，脂质组学技术仍有较大的提升空间。作者系统介绍了家畜精子的脂质组基本特征，并总结了脂质组学在精液质量评价和体外保存研究领域的发展现状，同时对其未来发展趋势进行了展望。     

茶多酚（GTPP）的抗脂质过氧化作用

活性氧和自由基引发的脂质过氧化反应与细胞突变或机体衰老及多种疾病的发生发展密切相关［１］。细胞代谢过程中连续不断产生的具有高度活性的自由基和细胞自身的抗氧化酶不断消除作用的失衡,致使体内自由基过剩,自由基及其诱导的氧化反应会引起细胞膜中含量丰富的脂类物质发生氧化作用,产生过氧化脂质（ＬＰＯ）。ＬＰＯ的产生和积累,导致生物膜功能障碍和膜酶及其他生物大分子的损伤,从而影响细胞活性物质的正常代谢,促进衰老和诱发疾病。这种过量自由基导致脂质过氧化反应的非组织特异性,使得体内重要脏器如肝、心、脑等都有受害…     

超氧化物歧化酶研究和应用进展

超氧化物歧化酶是一类广泛存在于动物、植物和微生物多种生物体内的金属酶,与铜(Cu)、锌(Zn)、铁(Fe)、锰(Mn)等微量元素代谢有密切关系.该酶是生物体内一种重要的氧自由基清除剂,具有重要的生物学功能,已成为化学、生物学、医学、食品科学和畜牧兽医学等多个学科领域研究的热点.文章从其来源、种类和分布,结构和理化特性,基因克隆、表达和调控,蛋白的制备,开发应用等方面进行了回顾和综述,并就存在的问题和前景进行了分析和探讨.     

The Structure and Function of Epidermal Lipids

Abstract— This review article examines current knowledge of the structure and function of epidermal lipids in human and veterinary dermatology. Dynamic transformations in lipid composition and structure occur as cells migrate through the epidermis. The lipids which are formed have a direct effect on epidermal functions. Ceramides appear to be the most important lipid component for lamellar arrangement in the stratum corneum and barrier protection. Polyunsaturated fatty acids in the epidermis are also important because they are incorporated into the ceramides. Additionally, arachidonic acid is bound to the phospholipid portion of cell membranes and is the most important precursor of endogenous eicosanoids. The eicosanoids are vital for epidermal homeostasis and play an important role in the pathogenesis of inflammatory dermatoses when produced in abnormal quantities. In addition to barrier protection, other vital epidermal functions associated with the lipids include stratum corneum water-holding, cohesion and desquamation of corneocytes, and control of epidermal proliferation and differentiation.     

Characteristics of lipids and their feeding value in swine diets

In livestock diets, energy is one of the most expensive nutritional components of feed formulation. Because lipids are a concentrated energy source, inclusion of lipids are known to affect growth rate and feed efficiency, but are also known to affect diet palatability, feed dustiness, and pellet quality. In reviewing the literature, the majority of research studies conducted on the subject of lipids have focused mainly on the effects of feeding presumably high quality lipids on growth performance, digestion, and metabolism in young animals. There is, however, the wide array of composition and quality differences among lipid sources available to the animal industry making it essential to understand differences in lipid composition and quality factors affecting their digestion and metabolism more fully. In addition there is often confusion in lipid nomenclature, measuring lipid content and composition, and evaluating quality factors necessary to understand the true feeding value to animals. Lastly, advances in understanding lipid digestion, post-absorption metabolism, and physiological processes(e.g., cell division and differentiation, immune function and inflammation); and in metabolic oxidative stress in the animal and lipid peroxidation, necessitates a more compressive assessment of factors affecting the value of lipid supplementation to livestock diets. The following review provides insight into lipid classification, digestion and absorption, lipid peroxidation indices, lipid quality and nutritional value, and antioxidants in growing pigs.     

The effect of retinol on the changes of lipid composition in serum of rabbit

Serum retinol is considered to increase when the beef cattle is fattened up or in a muscle marbling process. We examined the effects of retinol on the total lipids, triglycerides, phospholipids, cholesterols and lipid peroxides using rabbits. The animals were given 15,000 or 150,000 IU/kg of retinol (retinyl palmitate) intramuscularly once every 4 days for 48 days. When treated with 150,000 IU/kg of retinol, animals showed changes in the serum concentrations of total lipids, triglycerides, phospholipids, cholesterols and lipid peroxides. In particular, lipid peroxides remarkably increased. These results indicated that retinol accelerated the oxidation of serum lipids and that the effect of retinol was more prominent in unsaturated fatty acids than in saturated fatty acids. Furthermore, it was suggested that a large amount of administrated retinol may cause qualitative change of lipid composition in muscle.     

Evaluating the quality of feed fats and oils and their effects on pig growth performance

Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition,quality, feeding value, and price among sources. Common measures of lipid quality include moisture, insolubles,and unsaponifiables(MIU), titer, and free fatty acid content, but provide limited information regarding their feeding value. Lipid peroxidation is an important quality factor related to animal growth performance and health, but maximum tolerable limits in various lipids have not been established. Several indicative assays can be used to detect the presence of various peroxidation compounds, but due to the complexity and numerous compounds produced and degraded during peroxidation process, no single method can adequately determine the extent of peroxidation. Until further information is available, using a combination of peroxide value, thiobarbituric acid reactive substances(TBARS), and anisidine value appear to provide a reasonable assessment of the extent of peroxidation in a lipid at a reasonable cost. However, fatty acid composition of the lipid being evaluated should be considered when selecting specific assays. Predictive tests can also be used to estimate the stability or susceptibility of lipids to peroxidation and include active oxygen method, oil stability index, and oxygen bomb method. A review of 16 published studies with pigs has shown an average decrease of 11.4% in growth rate, 8.8% feed intake fed isocaloric diets containing peroxidized lipids compared to diets containing unperoxidized lipids of the same source.Furthermore, serum vitamin E content was generally reduced and serum TBARS content was increased when peroxidized lipids were fed in these studies, suggesting that feeding peroxidized lipids negatively affects metabolic oxidative status of pigs. However, it is unclear if antioxidants are useful additions to lipids to maintain optimal nutritional value, or if their addition to swine diets is beneficial in overcoming a metabolic oxidative challenge.     

Lipolysis and ultrastructural changes of intracellular lipid vesicles after cooling of bovine and porcine GV-oocytes

The aim of our investigation was to compare the ultrastructure of lipid droplets, and the effect of cooling on intracellular lipid vesicles of bovine and porcine GV oocytes. The lipid droplets in bovine GV oocytes have a homogeneous structure. The utilization of lipids takes place directly from these vesicles without formation of interim lipid compounds. In contrast, there are two kinds of lipid droplets in porcine GV oocytes: 'dark', homogeneous vesicles next to 'grey' vesicles with electron-lucent streaks. Vesicles of each specific group are connected to each other. After a 12-h culture, the formation of the cisternal smooth endoplasmic reticulum layer was always associated with 'grey' lipid vesicles. This is evidence that during oogenesis lipolysis takes place only in 'grey' vesicles. It is supposed that cytoplasmic lipolysis has two stages: 'dark' vesicles change into a 'grey' form followed by a utilization of these 'grey' lipids. Furthermore, both types of lipid droplets in porcine oocytes changed morphologically during cooling: they changed into a spherical form with lucent streaks. Lipid droplets in bovine GV oocytes revealed no visible morphological changes after cooling.     

Electron microscopic observations of stratum corneum intercellular lipids in normal and atopic dogs.

The barrier function of mammalian skin is maintained by intercellular stratum corneum lipids. In human patients with atopic dermatitis, an abnormal lipid barrier results in dry skin and increased transepidermal water loss. At this time, it is not known if a defective lipid barrier is present in atopic dogs. Normal and atopic canine skin were postfixed in ruthenium tetroxide and studied using transmission electron microscopy to determine structural differences within stratum corneum lipids. Intercellular lipid lamellae were graded on a semiquantitative scale. The deposition of stratum corneum lipid lamellae in atopic canine skin appeared markedly heterogeneous compared with that seen in normal canine skin. When present, the lamellae often exhibited an abnormal structure. The continuity and thickness of the intercellular lipid lamellae were significantly less in nonlesional atopic than in normal canine skin. These preliminary observations suggest that the epidermal lipid barrier is defective in atopic canine skin. Additional studies are needed to further characterize the biochemical defect and to possibly correct it with nutritional and/or pharmacologic intervention.     

Phospholipid- and fatty acid-composition in the erythrocyte membrane of the one-humped camel [Camelus dromedarius] and its influence on vesicle properties prepared from these lipids

The lipid composition of the membrane of erythrocytes from the one-humped camel (Camelus dromedarius) concerning the different lipid classes and the fatty acids was investigated for the first time. The most frequently occurring lipids are sphingomyelin (28.8% of total lipids), phosphatidylcholine and phosphatidylserine (each about 12%). The cholesterol/lipid ratio was calculated to be 0.30 (w/w). The fatty acids consist of shorter and/or more unsaturated chains, which resulted in a more fluid membrane compared to human RBC membranes. Liposomes prepared from erythrocyte lipid extracts were used to investigate the membrane properties resulting from this special lipid mixture. These vesicles were sufficient stable in buffer and significantly more stable than vesicles prepared from human erythrocyte lipid extracts in serum at 37 degrees C. Lipoplexes prepared from cationic erythrocyte lipid liposomes and a reporter gene showed in vitro an improved transfection on two colon carcinoma cells with an enhancement of up to 400% in beta-galactosidase activity in comparison to Lipofectin.     

Differential effects of Mycobacterium bovis - derived polar and apolar lipid fractions on bovine innate immune cells

ABSTRACT: Mycobacterial lipids have long been known to modulate the function of a variety of cells of the innate immune system. Here, we report the extraction and characterisation of polar and apolar free lipids from Mycobacterium bovis AF 2122/97 and identify the major lipids present in these fractions. Lipids found included trehalose dimycolate (TDM) and trehalose monomycolate (TMM), the apolar phthiocerol dimycocersates (PDIMs), triacyl glycerol (TAG), pentacyl trehalose (PAT), phenolic glycolipid (PGL), and mono-mycolyl glycerol (MMG). Polar lipids identified included glucose monomycolate (GMM), diphosphatidyl glycerol (DPG), phenylethanolamine (PE) and a range of mono- and di-acylated phosphatidyl inositol mannosides (PIMs). These lipid fractions are capable of altering the cytokine profile produced by fresh and cultured bovine monocytes as well as monocyte derived dendritic cells. Significant increases in the production of IL-10, IL-12, MIP-1β, TNFα and IL-6 were seen after exposure of antigen presenting cells to the polar lipid fraction. Phenotypic characterisation of the cells was performed by flow cytometry and significant decreases in the expression of MHCII, CD86 and CD1b were found after exposure to the polar lipid fraction. Polar lipids also significantly increased the levels of CD40 expressed by monocytes and cultured monocytes but no effect was seen on the constitutively high expression of CD40 on MDDC or on the levels of CD80 expressed by any of the cells. Finally, the capacity of polar fraction treated cells to stimulate alloreactive lymphocytes was assessed. Significant reduction in proliferative activity was seen after stimulation of PBMC by polar fraction treated cultured monocytes whilst no effect was seen after lipid treatment of MDDC. These data demonstrate that pathogenic mycobacterial polar lipids may significantly hamper the ability of the host APCs to induce an appropriate immune response to an invading pathogen.     

急性冷刺激后巴马猪背膘和腹股沟皮下脂肪组织的脂质组比较

本研究旨在获得巴马猪皮下脂肪组织（包括背膘（backfat）和腹股沟皮下脂肪组织（inguinal subcutaneous white adipose tissue，iWAT））在急性冷刺激（4 ℃、4 h）后其脂质组成应答的差异。正常饲喂的6月龄巴马公猪在急性冷刺激处理后进行屠宰，收集背膘和腹股沟皮下脂肪组织，利用液相二级质谱（LC-MS/MS）高通量脂质组学检测技术分析其脂质组成。结果表明，在巴马猪皮下脂肪组织中，中性脂类、游离脂肪酸、磷脂类和鞘脂类4大类脂质含量差异巨大，其中含量最高的为中性脂类，在腹股沟皮下脂肪组织和背膘中分别占4大脂类总和的97.43%和98.53%；含量最低的为鞘脂类，在腹股沟皮下脂肪组织和背膘中所占比例分别为0.10%和0.07%。在16亚类脂质组成中含量最高的脂质为甘油三酯，在腹股沟皮下脂肪组织和背膘分别占16亚类脂质总和的95.97%和97.33%；含量最低的脂质为磷脂酸，在腹股沟皮下脂肪组织和背膘中所占比例分别为3.98E-04%和1.13E-04%。主成分分析表明，背膘和腹股沟皮下脂肪组织在急性冷刺激后脂质组成存在差异。以∣差异倍数∣>1.5和P<0.05为标准筛选，共获得18种差异显著的脂类，其中16种脂类在背膘中含量显著低于腹股沟皮下脂肪组织，其中包括14种甘油三酯、DAG32：1（16：1/16：0）和PE40：6p；只有2种脂质（CL74：8（18：2）和TAG54：3（16：0））在背膘中的含量显著高于腹股沟皮下。巴马猪皮下脂肪主要脂质组成为甘油三酯；急性冷刺激后，背膘和腹股沟皮下脂肪组织对急性冷刺激存在不同的应答。     

Comparison of Lipid Profiles of Backfat and Inguinal Subcutaneous White Adipose Tissue from Acute Cold-treated Bama Pigs

This experiment aimed to study the difference of lipid metabolism between backfat and inguinal subcutaneous white adipose tissue (iWAT) after acute cold exposure (4 ℃ for 4 h).The LC-MS/MS based lipidomics of backfat and iWAT from chow diet-fed and cold-treated six-month-old male Bama pigs were profiled.The results showed that the content of 4 lipids classes,including neutral lipids,free fatty acids,phospholipids and sphingolipids were varies greatly in iWAT of Bama pigs.The highest lipid class in both iWAT and backfat was neutral lipids,which accounted for 97.43% and 98.53% respectively;The lowest lipid class was sphingolipids,which accounted for 0.10%and 0.07% in iWAT and backfat,respectively.Among 16 subclass lipids,the highest content in iWAT and backfat was TAG,which accounted for 95.97% and 97.33%,respectively,while the lowest content was PA,which accounted for 3.98E-04% and 1.13E-04% in iWAT and backfat,respectively.PCA analysis showed that backfat and iWAT could be separated clearly,which indicated the distinct changes in lipid composition of both fat tissues.And 18 different lipid species were determined using a criteria of fold change>1.5 and P<0.05,the results showed that 16 lipid species were significantly downregulated in backfat,including 14 TAGs,DAG32:1 (16:1/16:0) and PE40:6p.Two lipid species,including CL74:8(18:2) and TAG54:3 (16:0),were observed to be upregulated in backfat.The above results indicated that TAG was the main content of iWAT in Bama pigs,the backfat and iWAT had different physiological responses for acute cold stimulation.