Expression and Functional Analysis of Toll-Like Receptors of Peripheral Blood Cells in Asthmatic Patients: Implication for Immunopathological Mechanism in Asthma

Background  We investigated the expression profile of toll-like receptors (TLRs) and TLR ligand-activated production profile of asthma-related inflammatory cytokines in asthmatic patients. The expression of TLR1–8 on monocytes, CD4+ T helper lymphocytes, CD8+ T cytotoxic lymphocytes, CD19+ B lymphocytes, and dendritic cells, and ex vivo production of cytokines from peripheral blood mononuclear cells activated by TLR ligands were measured by flow cytometry. Discussion  Ex vivo productions of TNF-α, IL-10, and IL-1β by TLR4 and TLR5 ligand LPS and flagellin were significantly lower in asthmatic patients (all P < 0.05). Expression of TLR4 and TLR5 was also found to be significantly lower in asthmatic patients when compared to that of control subjects (all P < 0.05). Therefore, the decreased activation of TLR4 and TLR5 in asthmatic patients might contribute to the immunopathological mechanisms of asthma by reducing the release of Th1 and anti-inflammatory cytokines. Samantha W. M. Lun and C. K. Wong contributed equally to this study.     

Peripherally administered ghrelin induces bimodal effects on the mesolimbic dopamine system depending on food-consumptive states

Ghrelin induces orexigenic behavior by activation of growth hormone secretagogue 1 receptors (GHSRs) in the ventral tegmental area (VTA) as well as hypothalamus, suggesting the involvement of mesolimbic dopamine system in the action of ghrelin. The present study aimed to identify neuronal mechanisms by which peripherally administered ghrelin regulates the mesolimbic dopamine system under different food-consumptive states. Ghrelin was administered to rats peripherally (3 nmol, i.v.) as well as locally into the VTA (0.3 nmol). Dopamine in the nucleus accumbens shell (NAc) was measured by microdialysis. Peripheral administration of ghrelin decreased dopamine levels in the NAc when food was removed following ghrelin administration. This inhibitory effect was mediated through GABA_A and N-methyl-d-aspartate (NMDA) receptors in the VTA. In contrast, when animals consumed food following ghrelin administration, dopamine levels increased robustly. This stimulatory effect was mediated through NMDA receptors, but not through GABA_A receptors, in the VTA. Importantly, both the inhibitory and stimulatory effects of ghrelin primarily required activation of GHSRs in the VTA. Furthermore, local injection of ghrelin into the VTA induced dopamine release in the NAc and food consumption, supporting the local action of ghrelin in the VTA. In conclusion, peripherally administered ghrelin activates GHSRs in the VTA, and induces bimodal effects on mesolimbic dopamine neurotransmission depending on food-consumptive states.     

Role of peripheral and spinal 5-HT6 receptors according to the rat formalin test

The present study assessed the possible pronociceptive role of peripheral and spinal 5-HT₆ receptors in the formalin test. For this, local peripheral administration of selective 5-HT₆ receptor antagonists N-[3,5-dichloro-2-(methoxy)phenyl]-4-(methoxy)-3-(1-piperazinyl)-benzenesulphonamide (SB-399885) (0.01–1 nmol/paw) and 4-iodo-N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]benzene-sulfonamide hydrochloride (SB-258585) (0.001–0.1 nmol/paw) significantly reduced formalin-induced flinching. Local peripheral serotonin (5-HT) (10–100 nmol/paw) or 5-chloro-2-methyl-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole hydrochloride (EMD-386088) (0.01–0.1 nmol/paw; a selective 5-HT₆ receptor agonist) augmented 0.5% formalin-induced nociceptive behavior. The local pronociceptive effect of 5-HT (100 nmol/paw) or EMD-386088 (0.1 nmol/paw) was significantly reduced by SB-399885 or SB-258585 (0.1 nmol/paw). In contrast to peripheral administration, intrathecal injection of 5-HT₆ receptor antagonists SB-399885 and SB-258585 (0.1–10 nmol/rat) did not modify 1% formalin-induced nociceptive behavior. Spinal 5-HT (50–200 nmol/rat) significantly reduced formalin-induced flinching behavior during phases 1 and 2. Contrariwise, intrathecal EMD-386088 (0.1–10 nmol/rat) dose-dependently increased flinching during phase 2. The spinal pronociceptive effect of EMD-386088 (1 nmol/rat) was reduced by SB-399885 (1 nmol/rat) and SB-258585 (0.1 nmol/rat). Our results suggest that 5-HT₆ receptors play a pronociceptive role in peripheral as well as spinal sites in the rat formalin test. Thus, 5-HT₆ receptors could be a target to develop analgesic drugs.     

手术应激对成年和婴幼鼠吞噬受体表达及其细菌杀灭能力的影响

目的 吞噬作用是宿主固有免疫抵御外来入侵病原微生物的一个关键因素.手术应激可产生机体免疫抑制,增加感染的危险.本研究旨在探讨手术应激对成年鼠和婴幼鼠吞噬受体表达及其细菌杀灭能力的影响,分析吞噬体成熟及杀菌机制,进而为临床干预提供依据.方法 取婴幼(1～2周龄)和成年(8～10周龄)Balb/C小鼠各40只,分为对照组和手术应激组.腹腔灌洗法分别取术后24 h和对照组腹腔巨噬细胞,流式细胞仪测定巨噬细胞表面吞噬受体FcγR和CR3的表达;巨噬细胞与活菌共同孵育不同时间,计数细菌菌落生长数,计算胞内细菌杀灭数.结果 经流式细胞仪测定,对照组婴幼鼠巨噬细胞吞噬受体CR3和FcγR荧光强度分别为261.77±22.75和38.42±4.29,较对照组成年鼠(453.33±23.80、43.07±12.01)表达低(P＜0.05);手术应激后,婴幼鼠表达(49.87±3.04、9.57±0.76)明显下降(P＜0.05),而成年鼠表达(263.00±9.33、45.43±1.98)下降不明显.与细菌共培养30 min和60 min后,细菌吞噬率分别为43.75％±4.70％和61.29％±10.94％,较成年鼠(58.34％±8.87％和76.02％±3.64％)低(P＜0.05),手术应激后,婴幼鼠细菌吞噬率(38.06％±12.90％和56.15％±11.00％)亦有所下降.结论 婴幼鼠较成年鼠吞噬受体表达低,细菌杀灭能力弱.手术应激后,婴幼鼠吞噬受体的表达进一步降低,吞噬功能明显受损,细菌杀灭能力进一步下降,从而增加了术后感染的风险.     

脓毒症时机体免疫机制变化及意义

脓毒症是感染引起的全身炎症反应综合征,发生机制涉及炎症、感染、免疫、凝血及组织损伤等,其中免疫功能紊乱导致的促炎反应/抗炎反应动态失衡是其发展的重要原因之一.本文扼要介绍Toll样受体、中性粒细胞、树突状细胞和调节性T细胞等因素在免疫反应中的作用机制,以及在脓毒症发病中的变化与意义.     

肝X受体与代谢综合征代谢紊乱

肝X受体是与代谢综合征相关的核受体之一,对体内胆固醇的平衡和脂代谢的调控起重要作用.肝X受体能增加组织对葡萄糖的利用,延缓胰岛素抵抗,同时对胰岛β细胞有不利的作用.肝X受体影响脂肪细胞分化和下调肥胖基因的表达而引发肥胖,参与非酒精性脂肪肝的发生发展,同时具有控制动脉粥样硬化的作用,并参与巨噬细胞和淋巴细胞的炎症反应.作为代谢通路与炎症反应信号通路的结合点,肝X受体有望作为治疗代谢综合征的新靶点.     

Expression of metastasis-associated protein 1 (MTA1) in benign endometrium and endometrial adenocarcinomas

Endometrial carcinoma is one of the most common malignancies of the female genital tract. Metastasis-associated protein 1 (MTA1) is a component of the Mi-2/nucleosome remodeling and deacetylating complex and acts as a potent corepressor of estrogen receptor in breast cancer cells. MTA1 expression has been demonstrated in various cancers but has never been explored in endometrial carcinoma. We investigated the expression profile of MTA1 in different stages of benign endometrium as well as in endometrial endometrioid adenocarcinoma using immunohistochemistry and Western blotting. In the proliferative and secretory phases, MTA1 was expressed in both the glandular and the stromal compartments and was localized in nucleus and cytoplasm of these cells. MTA1 expression in secretory phase was less prominent when compared with the proliferative phase. In postmenopausal sections, MTA1 staining was observed in both glandular and stromal compartments and was localized in both nucleus and cytoplasm. Western blot analysis of 6 tumor specimens showed increased expression of MTA1 in all the tumors analyzed. Immunohistochemical staining performed on tumor microarray containing 70 endometrial endometrioid adenocarcinomas of various grades showed increased expression of MTA1 in 53 (75.7%) tumors. In grade 1 and grade 2 tumors, MTA1 was present in both nucleus and cytoplasm. Interestingly, in grade 3 tumors, MTA1 was localized in the cytoplasm only. Our results suggest a potential role of MTA1 in endometrial carcinomas.     

Calcium ions and integration in neural circuits

Integration in the nervous system is achieved by signal processing within dynamic functional ensembles formed by highly complex neuronal-glial cellular circuits. The interactions between electrically excitable neuronal networks and electrically non-excitable glial syncytium occur through either chemical transmission, which involves the release of transmitters from presynaptic terminals or from astroglial cells, or via direct intercellular contacts, gap junctions. Calcium ions act as a universal intracellular signalling system, which controls many aspects of neuronal-glial communications. In neurones, calcium signalling events regulate the exocytosis of neurotransmitters and establish the link between excitation of postsynaptic cells and integrative intracellular events, which control synaptic strength, expression of genes and memory function. In glial cells metabotropic receptor mediated release of calcium ions from the intracellular endoplasmic reticulum calcium store provide specific form of glial excitability. Glial calcium signals ultimately result in vesicular secretion of "glio" transmitters, which affect neuronal networks thus closing the glial-neuronal circuits. Cellular signalling through calcium ions therefore can be regarded as a molecular mechanism of integration in the nervous system.