Th17细胞与肝脏疾病

辅助性T细胞(Th细胞)根据产生细胞因子和生物学功能分为Th1和Th2细胞.最近研究发现了一种与Th1和Th2细胞亚群不同的活化CD4+T细胞亚群-Th17细胞.TGF-β与IL-6或IL-21的协同作用,诱导Th17细胞分化.IL-12家族的IL-23在促进IL-17分泌、增强Th17细胞效应功能方面发挥重要作用,而RORγt是其特异性转录因子.分化成熟的Th17细胞可以分泌IL-17A、IL-17F、IL-21、IL-22、IL-6、TNF-α等多种细胞因子,在介导炎性反应(防御病原菌感染)、自身免疫性疾病、肿瘤、移植排斥反应等过程中发挥重要作用.Th17细胞也为研究肝脏疾病的发病机制及防治策略提供了新思路和方向.     

Th17细胞与支气管哮喘

T辅助细胞17(Th17细胞)是一种新的CD4+效应T细胞亚群,以分泌白介素(IL)-17A和IL-17F为特征.自被发现以来,Th17细胞被认为在感染时宿主防御及自身免疫所引起的组织炎症中起着重要的作用.近年来,研究者们认为Th17细胞及相关细胞因子亦参与支气管哮喘的形成.一、Th17细胞的发现在Th17细胞被命名为一个独立的T细胞亚型之前,人们已经知道IL-17是活化的CD4+ T细胞所分泌的细胞因子,并且在宿主防御及自身免疫疾病方面发挥着重要的作用.In-fante-Duarte C等[1]首次阐述了Th17细胞,即一种独立于Th1、Th2以外的T细胞亚群.他们在研究中发现,人或鼠CD4+细胞在受到莱姆病螺旋体或分枝杆菌裂解物刺激后分泌IL-17,但并不同时分泌干扰素-γ(IFN-y),且在Th1及Th2细胞体外培养中发现,并没有培养出分泌IL-17细胞群,由此分析出IL-17与Th1、Th2细胞并没有相关性.Murphy CA等[2]在鼠自身免疫疾病模型中发现,缺少IL-23对IFN--γ的分泌并没有产生影响,但是对IL-17的生成却是必需的.进一步证明,IFN-γ与IL-17来源于不同的T细胞亚群,且发现IL-23可能诱导分泌IL-17的T细胞亚群的增殖.有研究者进一步研究发现,原始CD4+T细胞在体内及体外实验中均能分化为产IL-17的T细胞亚群,且不同于Th1、Th2亚群[3].故这一类Th细胞被研究者们称为Th17细胞.     

Th17细胞与肝脏疾病

辅助性T细胞（Th细胞）根据产生细胞因子和生物学功能分为Th1和Th2细胞。最近研究发现了一种与Th1和Th2细胞亚群不同的活化CD4^＋T细胞亚群-Th17细胞。TGF-8与IL-6或IL-21的协同作用,诱导Th17细胞分化。IL-12家族的IL-23在促进IL-17分泌、增强Th17细胞效应功能方面发挥重要作用,而RORγt是其特异性转录因子。分化成熟的Th17细胞可以分泌IL-17A、IL-17F、IL-21、IL-22、IL-6、TNF—α等多种细胞因子,在介导炎性反应（防御病原菌感染）、自身免疫性疾病、肿瘤、移植排斥反应等过程中发挥重要作用。Th17细胞也为研究肝脏疾病的发病机制及防治策略提供了新思路和方向。     

Th17细胞在肝脏疾病中的免疫病理作用

Th17细胞是效应性CD4+T细胞家族的新成员,由IL-6、TGF-β和IL-23等细胞因子诱导和维持分化,通过分泌IL-17、IL-21和IL-22等细胞因子参与炎症、自身免疫性疾病、肿瘤、移植排斥等过程。近年研究证实Th17细胞与多种肝脏疾病有关。     

Th17细胞与自身免疫性疾病的关系

根据细胞的功能,经典地将CD4+T细胞分为Th1、Th2辅助细胞以及调节性T细胞3个亚群.Yh1细胞通过分泌干扰素(IFN)-γ、白细胞介素(IL)-12等细胞因子,在抗感染、抗肿瘤反应中发挥重要作用,而同时,Th1活性异常升高也是器官特异性自身免疫病发病的重要机制之一;Th2细胞则通过分泌IL-4、IL-5、IL-13等细胞因子促进机体的体液免疫应答,另一方面也参与了哮喘、系统性自身免疫病的发病过程;而调节性T细胞则在维护机体免疫平衡中发挥了重要作用~[1].然而随着研究的深入发现,一群在分化、生物学作用等方面都不同于Th1、Th2、调节性T细胞的细胞亚群,它们不表达IL-4或IFN-γ,却高水平分泌IL-17,被命名为Th17细胞~[2].现就近年来关于Th17细胞的分化发育及其在相关疾病中的作用作一综述.     

辅助性T17细胞与系统性红斑狼疮相关性研究进展

系统性红斑狼疮(systemic lupus erythematosus,SLE)是一种多系统受累的自身免疫性疾病,发病与遗传、病毒感染、环境等多种因素有关.效应性CD4+T细胞即辅助性T细胞(Thelper,Th)在机体免疫应答和免疫调节中发挥着重要作用.根据发育、功能及分泌细胞因子的作用不同,CD4+T细胞分为Th1细胞、Th2细胞、调节性T细胞和Th17细胞4个亚群.Th17细胞分泌白细胞介素(IL)-17A、IL-17F、IL-21及IL-22等细胞因子,在许多自身免疫性疾病的发病机制中起作用[1].本文就近几年来对Th17细胞的发育分化机制、免疫调节、分泌细胞因子及与SLE相关性的研究进展总结如下.     

辅助性T17细胞与系统性红斑狼疮相关性研究进展

系统性红斑狼疮(systemic lupus erythematosus,SLE)是一种多系统受累的自身免疫性疾病,发病与遗传、病毒感染、环境等多种因素有关.效应性CD4+T细胞即辅助性T细胞(Thelper,Th)在机体免疫应答和免疫调节中发挥着重要作用.根据发育、功能及分泌细胞因子的作用不同,CD4+T细胞分为Th1细胞、Th2细胞、调节性T细胞和Th17细胞4个亚群.Th17细胞分泌白细胞介素(IL)-17A、IL-17F、IL-21及IL-22等细胞因子,在许多自身免疫性疾病的发病机制中起作用[1].本文就近几年来对Th17细胞的发育分化机制、免疫调节、分泌细胞因子及与SLE相关性的研究进展总结如下.     

Th17细胞及其相关疾病的研究进展

Th17细胞是一类独立于Th1、Th2的CD4^＋T细胞亚群,在其分化过程中需要白细胞介素（IL）-6和转化生长因子-β、转录因子ROR-γt及STAT3等参与,分泌IL-17、IL-22、IL-6等多种细胞因子,并参与多种炎症反应、自身免疫性疾病的发生发展,本文旨在阐述Th17细胞及其相关疾病的研究进展作一综述。     

Th17细胞与慢性阻塞性肺疾病发生发展的相关联系

慢性阻塞性肺疾病(COPD)的发病机制目前仍不清楚,但是中性粒细胞的募集和激活被认为与COPD的发病密切相关.最近,一类新型的CD4+T细胞亚群因能产生白介素17(IL-17),而被命名为Th17细胞.Th17细胞通过分泌IL-17、IL-22、肿瘤坏死因子a及IL-6等细胞因子,介导中性粒细胞的募集和激活,促使气道黏液高分泌的发生和发展,调节气道重塑,进而参与COPD的发病过程.本文旨在综述Th17细胞与COPD发生发展的相关联系.     

效应性T细胞亚群Th17与动脉粥样硬化

效应性T细胞亚群Th17是新近发现的效应性T细胞的又一亚群,因分泌细胞因子IL-17而得名。Th17通过分泌多种效应分子如白细胞介素17、17F、21和肿瘤坏死因子-α等与慢性炎症性疾病、自身免疫性疾病和肿瘤等疾病密切相关。研究发现,动脉粥样硬化的发生发展也与Th17功能的异常密切相关,现拟就此进行综述。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.