哺乳动物子宫自然杀伤(uNK)细胞对妊娠的调控作用

子宫自然杀伤(uterine natural killer, uNK)细胞是哺乳动物妊娠早期胎盘蜕膜中数量最多的免疫细胞。妊娠期间,uNK细胞对子宫免疫耐受环境建立,胎盘以及胎儿的发育等均具有重要调控作用。目前,有关妊娠中uNK细胞独特生物活性调控机制研究非常缺乏。本文综合相关研究,介绍了妊娠过程中uNK细胞在母-胎免疫耐受建立、胎盘和胎儿发育过程中重要调控作用,并总结激素、糖代谢以及DNA甲基化等对其他组织NK细胞调控机制研究,为探索uNK细胞调控分子机制提供新的研究方向和思路。     

哺乳动物子宫自然杀伤(uNK)细胞对妊娠的调控作用

子宫自然杀伤(uterine natural killer, uNK)细胞是哺乳动物妊娠早期胎盘蜕膜中数量最多的免疫细胞。妊娠期间,uNK细胞对子宫免疫耐受环境建立,胎盘以及胎儿的发育等均具有重要调控作用。目前,有关妊娠中uNK细胞独特生物活性调控机制研究非常缺乏。本文综合相关研究,介绍了妊娠过程中uNK细胞在母-胎免疫耐受建立、胎盘和胎儿发育过程中重要调控作用,并总结激素、糖代谢以及DNA甲基化等对其他组织NK细胞调控机制研究,为探索uNK细胞调控分子机制提供新的研究方向和思路。     

大足黑山羊妊娠不同阶段胎盘组织线粒体酶活性和超微结构变化

山羊的胎盘属于子叶型胎盘,胎盘子叶性状和结构与山羊繁殖性能具有较强的相关性。胎盘子叶组织线粒体发挥正常功能是保证胎儿生长发育,进而维持正常妊娠的关键。本试验采用大足黑山羊妊娠60,90,120d的胎盘和胎儿组织为研究对象,检测胎盘子叶及胎儿心、肝、脾、肺、肾组织的线粒体细胞色素C氧化酶(CCO)、琥珀酸脱氢酶(SDH)、Ca++-Mg++-ATP酶和Na+-K+-ATP酶的活性变化,并通过透射电镜技术观测胎盘子叶组织线粒体的形态结构。结果发现,胎盘子叶及胎儿心、肝、脾、肺、肾的线粒体CCO、SDH及ATP酶的活性都有随着妊娠时间的增加而显著提高的趋势,且在妊娠90~120d的上升趋势高于妊娠60~90d,表明妊娠中后期的胎儿生长发育所需要的能量较多;在同一妊娠阶段,胎盘子叶线粒体酶活性均高于胎儿各组织,且差异显著(P<0.05),说明胎盘子叶是妊娠过程中的重要部位,胎儿组织器官在发育过程中存在先后顺序,并且与该器官的功能作用有关;透射电镜观察发现,随着妊娠时间的增加胎盘线粒体数量增多,密度增大且主要聚集在子叶绒毛附近,这体现了胎盘子叶的营养交换作用。     

Leptin的生殖调控机制研究进展

Ｌｅｐｔｉｎ是一种具有多种生殖生理效应的活性多肽。研究表明，它促进生殖系统发育，参与卵母细胞动物极的决定，影响内细胞团的建立和滋养层的形成。在妊娠中参与附植，母体妊娠状态，胎盘功能和胎儿生长发育的调节，另外还影响多种生殖激素的释放。     

微小RNA调控母猪胎盘发育的研究进展

微小RNA(miRNA)是内源性非编码的小分子RNA,它们存在于动物、植物和病毒中，主要通过调控靶基因的翻译和mRNA稳定性而参与多种生理过程。胎盘是哺乳动物妊娠过程中存在的一个临时性的内分泌器官，对胎儿的发育至关重要。而母猪胎盘的不良发育不仅会影响到妊娠期仔猪的发育，还会对生产效益造成一定的损失。研究表明，miRNA对哺乳动物的胎盘滋养层细胞和血管生成等方面具有重要的调控作用。本文综述了miRNA生成过程及其功能，以及目前关于miRNA对母猪胎盘发育的调控作用，旨在为提高母猪繁殖效率、提高生产效益提供理论参考。     

胎盘氧化应激及营养调控研究进展

胎盘作为联系母体和胎儿的桥梁,是保障胎儿正常生长的前提条件。据报道胎盘氧化应激与妊娠疾病和胎儿的生长发育密切相关。文章综述了胎盘氧化应激与血管发生、凋亡、内质网应激、自噬和转运载体及营养调控方面的研究进展,为抗氧化剂在实际动物生产中的应用提供指导。     

反刍动物双核滋养层巨细胞及其妊娠特异蛋白家族的研究进展

双核滋养层巨细胞是反刍动物胎盘特有的滋养层巨细胞群。作为母胎界面的第1层细胞,其从胚胎附着启动直接参与子宫上皮的变形和母胎交换过程。研究发现,牛、绵羊和山羊的该细胞群能特异表达胎盘催乳素等妊娠特异蛋白家族,以参与胚胎附着、胎盘形成、血管发生、免疫调节和母胎交换等生理过程,在妊娠维持中起着不同的重要作用,但具体生物学功能和调节机制仍有待深入研究。本文综述了反刍动物双核滋养层巨细胞的特征和其妊娠特异蛋白家族表达及生物学功能的研究进展。     

绵羊日粮中添加亚硒酸钠对胎盘中SelP和ApoER-2蛋白表达的影响

试验通过在妊娠母羊日粮中添加不同水平的亚硒酸钠,研究硒对绵羊胎盘SelP和ApoER-2的蛋白表达的影响,为进一步揭示硒的胎盘转运及硒对胎儿发育的调控机制提供实验依据。选取体重、体型、年龄、胎次相近的湖羊妊娠母羊80只,随机分为两组,分别饲喂基础日粮和添加0.5 mg/(kg DM·d)亚硒酸钠的日粮。预试期7 d,正试期150 d。结果表明:SelP和ApoER-2主要在妊娠母羊胎盘滋养层细胞中表达。日粮中亚硒酸钠的添加,极显著提高了妊娠母羊胎盘滋养层细胞中SelP的表达量(P<0.01),却极显著降低了ApoER-2蛋白的表达量(P<0.01)。     

猪妊娠过程中胎盘发育及其调控基因研究进展

胎盘是母体与胎儿进行营养物质、气体及废弃物交换的重要器官。妊娠过程中,猪胎盘功能是影响母猪产仔数、死胎数及断奶前死亡率的最重要因素之一。作者介绍了猪妊娠早期胎盘的建立过程及形态变化、妊娠中期胎盘褶皱的形成、妊娠后期胎盘的进一步发育,阐述了这3个妊娠阶段猪胎盘的形态变化与其对应的胎盘功能之间的关系,并介绍了目前所发现的调控猪胎盘建立和发育的相关基因,包括透明质酸酶（HYAL）、组织蛋白酶（CTSB和CTSL1）及乙酰肝素酶（HPSE）基因,为提高母猪胎盘效率、增加母猪繁殖力提供科学依据。     

母猪流产常见原因及防治

母猪流产是指母猪在怀孕期间,由于各种原因造成胚胎或胎儿与母体之间的生理关系发生紊乱,致使妊娠中断,未充分完成其发育阶段的胚胎或胎儿被排出体外的现象。由于胎儿未足月便提前产出,所产出的胎儿一般已死或产出后不久即死。从生理结构来说,猪的胎盘属于弥散型胎盘（上皮-绒毛膜胎盘）,胎盘的绒毛基本上均匀分布绒毛膜上,绒毛膜插入子宫上皮腺窝内,绒毛膜从子宫内膜拔出并不牵连、伤及子宫内膜。此类胎盘结构较简单,     

猪繁殖与呼吸综合征感染与细胞凋亡的研究进展

细胞凋亡是指在一定的生理或病理情况下,机体为维护内环境的稳定,通过基因调控,激活内源性核酸内切酶,发生细胞自动消亡的过程。研究猪繁殖与呼吸综合征（PRRSV）感染与细胞凋亡的关系及凋亡的可能机制将有助于人们认识PRRSV感染性的发生、发展及转归机制,现综述国内外近年来对PRRSV诱导细胞凋亡的相关研究进展,为进一步阐明PRRSV的致病机制和该病的防治提供一些新的思路。     

细胞凋亡在肾脏疾病中的作用

细胞凋亡是基因调控的细胞生理性死亡形式 ,是一种主动、自发性的过程 ,是目前生物学和医学界的研究热点。文章通过对细胞凋亡的形态学、生物化学、免疫化学和分子生物学的检测方法、促进细胞凋亡和抑制细胞凋亡的基因、以及细胞凋亡与肾脏疾病的关联作一综述。旨在阐明细胞凋亡在肾小球肾炎、肾小管疾病以及继发性肾脏疾病等肾脏疾病发病机制中的重要作用     

Proliferation and Apoptosis in Fetal Membranes and Endometrium During Placental Retention in Heavy Draft Mares

Placental retention (retained placenta [RP]) is a serious and common peripartum disease in mares, but the etiology and pathogenesis of RP still remain unclear. The alteration of cell proliferation and apoptosis is considered to be an important factor in RP. Fetal membranes and endometrial biopsies were collected from mares with RP (n = 8) and from control mares (n = 10). The proliferation and apoptosis levels in the chorionic and the endometrial epithelia were assessed by proliferating cell nuclear antigen immunostaining and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, respectively. The study revealed that there was an insignificant decrease in proliferation and a significant increase in apoptosis in the chorionic epithelium from mares with RP. This result excludes a proliferation imbalance from the possible causes of RP. In the area of the nonpregnant horn of the placenta, proliferation was negatively correlated and apoptosis was positively correlated with the degree of fetomaternal anchorage. It was observed that, in all mares with placental retention, the endometrial epithelium (both luminal and glandular) showed decreased proliferation and increased apoptosis, which may indicate a delay in postpartum uterine regeneration.     

Proliferation and Apoptosis in Aged and Photoregressed Mammalian Seminiferous Epithelium,with Particular Attention to Rodents and Humans

Imbalances in the proliferation and apoptosis processes are involved in numerous epithelial alterations. In the seminiferous epithelium, normal spermatogenesis is regulated by spermatogonia proliferation and germ cell apoptosis, and both processes are involved in diverse pathological alterations of the seminiferous epithelium. Other physiological phenomena including aging and short photoperiod, in which apoptosis and proliferation seem to play important roles, cause testicular changes. Aging is accompanied by diminished proliferation and increased apoptosis, the latter occurring in specific states of the seminiferous cycle and considered the cause of epithelium involution. However, there is no clear evidence concerning whether proliferation decreases in the spermatogonia themselves or is due to an alteration in the cell microenvironment that surrounds them. As regards the factors that regulate the process, the data are scant, but it is considered that the diminution of c‐kit expression in the spermatagonia, together with the diminution in antiapoptotic factors (Bcl‐x_L)) of the intrinsic molecular pathway of apoptosis play a part in epithelial regression. A short photoperiod, especially in rodents, produces a gradual involution of the seminiferous epithelium, which is related with increased apoptosis during the regression phase and a diminution of apoptosis during recrudescence. Proliferative activity varies, especially during the total regression phase, when it usually increases in the undifferentiated spermatogonia. In other species showing seasonal reproduction, however, decreased proliferation is considered the main factor in the regression of the seminiferous epithelium. Little is known about how both phenomena are regulated, although data in rodents suggest that both the intrinsic and extrinsic pathways of apoptosis contribute to the increase in this process. In conclusion, regression of the seminiferous epithelium in physiological situations, as in many pathological situations, is a result of alterations in equilibrium between the proliferation and apoptosis of germinal cell types. However, both physiological phenomena showed important differences as regard proliferation/apoptosis and their regulation pathways, probably as a result of their irreversible or reversible character.     

Does Apoptosis Occur during Follicular Atresia in the Follicular Walls of the Porcine Ovary?

Contents In this experiment, the possibility that the follicular-wall cells' death during ovarian follicular atresia occurs as a result of apoptosis was examined. Programmed cell death or apoptosis is a process whereby cells die in a controlled fashion, triggered by changes in levels of specific physiological stimuli. Morphological transformations of the cells are preceded by endo- nuclease-mediated genomic-DNA cleavage. The analysis of DNA from the theca and granulosa layers of follicles indicated that internucleosomal fragmentation of DNA occurred in atretic granulosa cells but not in atretic theca cells. The healthy granulosa and theca cells in all classes of follicles showed no apoptosis. This paper demonstrates that the death of porcine ovarian-follicle walls can be caused by different processes and, contrary to granulosa cells' apoptosis, either does not or only partly concerns the internal theca layer.     

Caspase家族与细胞凋亡的关系

凋亡是导致细胞死亡的调节性生理过程。Caspase半胱氨酸蛋白酶家族引发的级联反应是细胞凋亡过程的中心环节,其激活主要包括线粒体依赖途径和死亡受体介导的信号转导途径,激活后的下游Caspase,通过切割特异性底物,导致细胞凋亡。现以Caspase家族与细胞凋亡的关系为主,对Caspase基因家族生物学特性、调控细胞凋亡的分子机制进行综述。     

Morphological and biochemical aspects of apoptosis,oncosis and necrosis

Recent investigations have demonstrated the need for a precise differentiation of various forms of cell death such as apoptosis, oncosis, necrosis and programmed cell death. Apoptosis is marked by cellular shrinking, condensation and margination of the chromatin and ruffling of the plasma membrane with eventually breaking up of the cell in apoptotic bodies. Cell death marked by cellular swelling should be called oncosis, whereas the term necrosis refers to the morphological alterations appearing after cell death. Apoptosis and oncosis are therefore pre-mortal processes, while necrosis is a post-mortal condition. The term programmed cell death refers to the 'fixed' pathway followed by dying cells, whether or not with the characteristic morphology of apoptosis. Three mechanisms are actually known to be involved in the apoptotic process: a receptor-ligand mediated mechanism, a mitochondrial pathway and a mechanism in which the endoplasmic reticulum plays a central role. All three mechanisms activate caspases which are responsible for the characteristic morphological changes observed during apoptosis. A review of the different methods used for detecting apoptotic cells demonstrates that most of these techniques are not entirely specific.     

Immunolocalization of gastrin-releasing peptide (GRP) in the uteroplacenta of the mouse deer

The considerable phylogenetical differences between mouse deer and other ruminants have been established by means of DNA sequence analysis and anatomical observations. To clarify the physiological role of the uteroplacenta of the mouse deer, immunohistochemical observation was attempted by using GRP, which has been suggested as a novel regulatory peptide in the female reproductive tract, as an indicator to compare with other ruminants. Strong positive reactions for the GRP were detected in the uterine glands of the pregnant animals, but not in the non-pregnant ones. Although the placenta of the mouse deer is categorized as a diffuse placenta that is different from other ruminants' polycotyledonary placenta, in terms of GRP immunoreactivity, the mouse deer placenta can be classified as a synepithecholial placenta like the other ruminants'. The secretion of GRP from the uterine glands is of some importance to the fetus in the mouse deer.     

Sensitivity of skeletal muscle to pro-apoptotic factors

In mononuclear cells, apoptosis leads to DNA fragmentation and cell destruction, regardless of the activated pathway. As regards multinuclear cells, e.g. skeletal muscle fibers, apoptosis rarely induces the death of the entire cell, and it generally affects single nuclei. This process, referred to as nuclear apoptosis, has a negative effect on the expression of genes in the myonuclear domain. Apoptosis may be initiated in muscle cells by external stimuli which activate cell membrane death receptors as well as by internal stimuli which stimulate the mitochondrial release of pro-apoptotic proteins. Reactive oxygen species also play an important role in the initiation of apoptosis. In muscle cells, ROS are produced in response to extracellular reactions or by cell mitochondria. It is, therefore, believed that mitochondria play a central role in apoptosis within skeletal muscle. Skeletal muscles have a well-developed system that protects them against oxidative damage. Myogenic stem cells are an integral part of multinucleated myofibers, and they are critically important for the maintenance of normal muscle mass, muscle growth, regeneration and hypertrophy. The latest research results indicate that myogenic cells are more sensitive to oxidative stress and pro-apoptotic factors than well-differentiated cells, such as myotubes. The complex structure and activity of skeletal muscle prompted research into the role of apoptosis and its intensity under various physiological and pathological conditions. This review summarizes the results of research investigating control mechanisms and the apoptosis process in skeletal muscle fibers, and indicates unresearched areas where further work is required.     

Current views on apoptosis in theory and medical practice

Apoptosis is a kind of cell death essential for normal functioning and survival of most multicellular organisms. Apoptosis plays an important role in physiological processes and in pathophysiology of some chronic diseases, including autoimmunity, cancer, lymphoma, AIDS, neurodegeneration and others. The present paper describes the interdisciplinary pathogenesis of programmed cell death, the mechanisms inducing apoptosis and the role of apoptosis in some physiological phenomena and in medical practice.