NLRs家族成员NLRC5在免疫反应方面的研究进展

NOD样受体(NLRs)是细胞内感应器,能对各种不同的病原体和细胞内危险信号作出应答,从而诱导固有免疫反应。NLRC5是该家族成员之一,目前已经证实NLRC5是核转录因子κB、Ⅰ型干扰素、炎性体信号路径及MHC-Ⅰ基因表达的重要调节器,在固有免疫反应和适应性免疫反应中发挥举足轻重的作用。本文就的相关研究作一综述。     

脂多糖和甲基磺酰苯丙氨酰氯甲酮对巨噬细胞源性泡沫细胞内胆固醇流出和ATP结合盒转运体A1表达的影响

目的观察脂多糖和核因子κB抑制削甲基磺酰苯丙氨酰氯甲（tosyl-phenylalanine chloromethyl-ketone，TPCK）对THP-1巨噬细胞源性泡沫细胞内胆固醇流出和ATP结合盒转运体A1（ABCA1）表达的影响，以探讨脂多糖是否通过Toll样受体4-核因子κB途径影响ABCA1的表达。方法THP-1细胞经佛波酯诱导转化为巨噬细胞，再加入ox-LDL培养使其转化为泡沫细胞，     

罗格列酮对NASH大鼠肝组织IKK-β表达、NF-κB活性的抑制作用

IKK-β是核因子κB（NF-κB）抑制蛋白（IκB）磷酸化激酶,为促炎因子激活NF-κB必需的催化亚单位。过氧化物酶体增殖物激活受体-γ（PPAR-γ）高亲和力配体罗格列酮,可通过抑制NF-κB活化和肿瘤坏死因子（TNF）-α等多种致炎基因表达,发挥抗炎及免疫调节作用。     

肠黏膜屏障损伤与保护分子机制研究进展

介绍肠黏膜屏障损伤因素的分子机制,如内毒素及氧自由基、炎症介质和细胞因子如白细胞介素（interleukin）、肿瘤坏死因子-α（TNF-α）、核转录因子kappa B、TOLL样受体（TLRs）和NOD受体通路、高迁移率族蛋白B1、烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶（NOX）等。对肠黏膜屏障的保护分子机制如肠上皮紧密连接蛋白、白介素家族、其它保护性调控因子等作出介绍。     

替米沙坦通过激活PPARγ而下调NF-κB通路抑制脂多糖诱导的单核细胞THP-1炎症反应

目的探讨替米沙坦（Telm）对脂多糖（LPS）诱导的人THP-1巨噬细胞炎症因子释放的影响及机制。方法体外培养人THP-1单核细胞随机分为对照组、脂多糖组和替米沙坦组（LPS+Telm）。替米沙坦组细胞予替米沙坦（10μmol/L）预孵育2h后与脂多糖组均加入脂多糖刺激24h。应用Westernblot检测各组细胞过氧化体增殖物激活型受体γ（PPARγ）、磷酸化过氧化体增殖物激活型受体γ（p-PPARγ）、IκBα、磷酸化IκBα（p-IκBα）、核因子κB（NF-κB）、磷酸化核因子κB（p-NF-κB）的蛋白表达,ELISA法检测各组细胞培养上清中单核细胞趋化蛋白1（MCP-1）、肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）的表达水平,应用实时定量PCR（RT-PCR）检测各组细胞MCP-1、TNF-α和IL-6的mRNA表达水平。结果Westernblot检测发现,与对照组相比,脂多糖组p-PPARγ、p-NF-κB和p-IκBα蛋白表达水平明显升高（P<0.05）,IκBα表达明显下降（P<0.05）,PPARγ和NF-κB表达水平无显著差异（P>0.05）;RT-PCR和ELISA检测发现,与对照组相比,脂多糖组MCP-1、TNF-α和IL-6蛋白水平和mRNA表达水平均明显增高（P<0.05）。与脂多糖组相比,替米沙坦组p-NF-κB和p-IκBα蛋白水平表达明显下降,MCP-1、TNF-α及IL-6分泌水平和mRNA水平也均明显降低,p-PPARγ和IκBα蛋白表达水平明显增加（P<0.05）,但是NF-κB和PPARγ表达水平依然无显著差异（P>0.05）。结论替米沙坦预处理可通过激活PPARγ而下调NF-κB活化从而抑制脂多糖诱导单核细胞THP-1产生炎症反应。     

核因子-κB与溃疡性结肠炎相关性的研究进展

核因子-κB（NF-κB）被认为是诱导炎性因子基因高表达的核心调节因子,广泛存在于各类细胞中。随着对NF—κB在溃疡性结肠炎（UC）发生、发展中作用认识的逐渐深入,近年诸多相关研究显示,NF—κB在结直肠炎性组织中呈高表达,它能促进多种炎性细胞因子如白细胞介素-1（IL-1）、IL-2、IL-6、IL-8、肿瘤坏死因子α（TNF—α）、Toll样受体等基因的转录,炎性因子激活后又可以正反馈促进NF—κB的活化,从而形成恶性循环,导致NF—κB的靶基因表达上调,促进UC的发生、发展。     

视黄酸相关孤核受体α对脓毒症小鼠心肌损伤的影响

目的 本研究旨在探索视黄酸相关孤核受体α（RORα）对脓毒症炎症反应及其所致的心脏功能损害影响。 方法 通过腹腔注射脂多糖（LPS）建立小鼠脓毒症模型，通过LPS刺激巨噬细胞，建立脓毒症细胞模型，采用细胞转染和小鼠尾静脉注射过表达质粒，以在细胞和组织中过表达RORα，进而探究RORα在脓毒症炎症反应和脓毒症所致心肌损伤中的作用。采用实时定量PCR试验、蛋白免疫印记试验检测RORα、NF-κB p65和炎症因子的变化，采用酶联免疫试验、病理切片等检测脓毒症小鼠心肌损伤的变化。 结果 RORα在LPS刺激巨噬细胞中显著降低（P<0.05）；过表达RORα能够显著抑制LPS刺激巨噬细胞中炎症因子白介素(IL)-1β和肿瘤坏死因子 (TNF)-α的表达（P<0.05）、NF-κB p65的核移位水平（P<0.05）、脓毒症小鼠血清中炎症因子IL-1β和TNF-α的释放、降低脓毒症小鼠肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）的含量以及改善脓毒症所致的心肌病理损害。 结论 RORα能够通过抑制NF-κB p65的核移位进而负性调控LPS刺激巨噬细胞中的炎症反应，从而缓解脓毒症小鼠的炎症反应及心肌损害。     

TLR4/MyD88/NF-κB信号通路与溃疡性结肠炎

溃疡性结肠炎(UC)是一种发病机制尚未完全明确的非特异性炎症性疾病,免疫反应异常是UC发病的主要原因。研究表明,Toll样受体4(TLR4)通过胞内白细胞介素-1受体(IL-1R)同源结构域,并利用IL-1R下游信号传递分子髓样分化因子88(MyD88)、IL-1R相关激酶(IRAK)、肿瘤坏死因子受体相关因子-6(TRAF6)等,介导病原体诱导内皮细胞中NF-κB的活化,产生免疫炎性细胞因子,从而导致UC的发生。本文就TLR4/MyD88/NF-κB信号通路与UC的发病作一综述。     

香烟及脂多糖等诱导巨噬细胞核因子κB的活化及其对黏附分子表达的调控

核因子κB(NF-κB)是炎症、免疫反应中一个关键的调控因子，其可在基因转录水平上调控细胞间黏附分子1(ICAM-1)的表达，有助于炎症和免疫反应^[1]。我们的研究通过检测经香烟烟雾提取物(CSE)、脂多糖(LPS)和肿瘤坏死因子α(TNF-α)诱导后不同时间点小鼠巨噬细胞NF-κB活化和ICAM-1表达的程度，以及地塞米松(DEX)对TNF-α、     

异常血流动力对TLR4/NF-κB信号传导通路及其下游炎症因子的影响

目的研究异常血流应力或压力单独作用对人脐静脉内皮细胞(Human umbilical vein endothelial cells,HUVECs)Toll样受体4(Toll-like receptor 4,TLR4)/NF-κB信号传导通路及下游炎症因子:血凝素样氧化低密度脂蛋白受体-1(lectin-like oxidized low-density lipoprotein receptor-1,LOX-1)、肿瘤坏死因子-α(TNF-α)、细胞间粘附分子-1(ICAM-1)及血管细胞粘附分子-1(VCAM-1)等的影响,探讨异常血流动力导致动脉粥样硬化的机制。方法将生长良好的HUVECs以1×105个/ml密度接种于细胞综合应力刺激实验系统(型号BIO-CCS13)中进行干预。将HUVECs按所受的应力不同分成应力组、压力组和正常组。在各组应力作用下培养一天后收集细胞备用,用q PCR方法测定TLR4、髓样分化因子88(myeloid differentiation factor 88,My D88)、肿瘤坏死因子受体相关因子-6(tumor necrosis factor receptor-associated factor-6,TRAF-6)、血凝素样氧化低密度酯蛋白受体-1(LOX-1)、核因子-κB(NF-κB)、TNF-α、ICAM-1及VCAM-1因子的基因表达,用蛋白质印迹方法测定TLR4、NF-κB、LOX-1、TNF-α、ICAM-1及VCAM-1因子的蛋白表达。结果与正常组比较,应力组和压力组TLR4、My D88、TRAF-6、LOX-1、NF-κB、TNF-α、ICAM-1及VCAM-1m RNA表达水平显著升高(P0.01),TLR4、LOX-1、NF-κB、TNF-α、ICAM-1及VCAM-1蛋白表达显著升高,差异有统计学意义(P0.01)。结论异常血流动力导致动脉粥样硬化的机制可能与激活TLR4/NF-κB信号传导通路和增强下游炎症因子:LOX-1、TNF-α、ICAM-1及VCAM-1等的表达有关。     

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.     

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.     

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.     

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.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.