Regulatory T cells use programmed death 1 ligands to directly suppress autoreactive B cells in vivo

The mechanisms by which regulatory T cells (T(regs)) suppress autoantibody production are unclear. Here we have addressed this question using transgenic mice expressing model antigens in the kidney. We report that T(regs) were essential and sufficient to suppress autoreactive B cells in an antigen-specific manner and to prevent them from producing autoantibodies. Most of this suppression was mediated through the inhibitory cell-surface-molecule programmed death-1 (PD-1). Suppression required PD-1 expression on autoreactive B cells and expression of the two PD-1 ligands on T(regs). PD-1 ligation inhibited activation of autoreactive B cells, suppressed their proliferation, and induced their apoptosis. Intermediate PD-1(+) cells, such as T helper cells, were dispensable for suppression. These findings demonstrate in vivo that T(regs) use PD-1 ligands to directly suppress autoreactive B cells, and they identify a previously undescribed peripheral B-cell tolerance mechanism against tissue autoantigens.     

Neuregulin and dopamine modulation of hippocampal gamma oscillations is dependent on dopamine D4 receptors

The neuregulin/ErbB signaling network is genetically associated with schizophrenia and modulates hippocampal γ oscillations-a type of neuronal network activity important for higher brain processes and altered in psychiatric disorders. Because neuregulin-1 (NRG-1) dramatically increases extracellular dopamine levels in the hippocampus, we investigated the relationship between NRG/ErbB and dopamine signaling in hippocampal γ oscillations. Using agonists for different D1- and D2-type dopamine receptors, we found that the D4 receptor (D4R) agonist PD168077, but not D1/D5 and D2/D3 agonists, increases γ oscillation power, and its effect is blocked by the highly specific D4R antagonist L-745,870. Using double in situ hybridization and immunofluorescence histochemistry, we show that hippocampal D4R mRNA and protein are more highly expressed in GAD67-positive GABAergic interneurons, many of which express the NRG-1 receptor ErbB4. Importantly, D4 and ErbB4 receptors are coexpressed in parvalbumin-positive basket cells that are critical for γ oscillations. Last, we report that D4R activation is essential for the effects of NRG-1 on network activity because L-745,870 and the atypical antipsychotic clozapine dramatically reduce the NRG-1-induced increase in γ oscillation power. This unique link between D4R and ErbB4 signaling on γ oscillation power, and their coexpression in parvalbumin-expressing interneurons, suggests a cellular mechanism that may be compromised in different psychiatric disorders affecting cognitive control. These findings are important given the association of a DRD4 polymorphism with alterations in attention, working memory, and γ oscillations, and suggest potential benefits of D4R modulators for targeting cognitive deficits.     

Seasonal effect of GnIH on gonadotrope functions in the pituitary of goldfish

Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin release in birds and mammals. To investigate its role in teleosts, we examined the effects of synthetic goldfish (g)GnIH on pituitary LH-β and FSH-β subunit, and gGnIH receptor (gGnIH-R) mRNA levels and LH secretion in goldfish. Intraperitoneal injections of gGnIH increased pituitary LH-β and FSH-β mRNA levels at early to late gonadal recrudescence, but reduced serum LH and pituitary gGnIH-R mRNA levels, respectively, at early to mid-recrudescence and later stages of recrudescence. Static incubation with gGnIH elevated LH secretion from dispersed pituitary cell cultures from prespawning fish, but not at other recrudescent stages; suppressed LH-β mRNA levels at early recrudescence and prespawning but elevated LH-β at mid-recrudescence; and consistently attenuated FSH-β mRNA in a dose-specific manner. Results indicate that in goldfish, regulation of LH secretion and gonadotropin subunit mRNA levels are dissociated in the presence of gGnIH and dependent on maturational status and administration route.     

Social Stress Alters Inhibitory Synaptic Input to Distinct Subpopulations of Raphe Serotonin Neurons

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Clinical study on anti-fungal drug activity against clinically isolated strains of oral Candida species

ObjectivesThe present study was undertaken to evaluate the anti-fungal activity of amphotericin B (AMPH-B), flucytosine (5-FC), fluconazole (FLCZ), miconazole (MCZ), itraconazole (ITCZ), and micafungin (MCFG) against clinically isolated Candida strains from oral candidiasis (OC) patients and to collect information useful for the treatment of OC.Subjects and methodsThe study includes 116 strains of Candida isolated from patients. The Candida species were identified by polymerase chain reaction. The minimum inhibitory concentration (MIC) of each drug against each Candida species was determined.ResultsOf the 106 participants (30 males and 76 females), 57 had OC, including 42 cases of pseudomembranous OC, 11 cases of erythematous OC, 2 cases of hypertrophic OC, and 2 cases of mixed pseudomembranous/erythematous OC. The Candida species isolated were Candida albicans (93 strains), C. glabrata (19 strains), and C. tropicalis (4 strains). AMPH-B and 5-FC had low MIC values against all species of Candida and a low incidence of resistance development. In some species of Candida, FLCZ and ITCZ showed high MICs, but MCZ had a low MIC value. AMPH-B, MCZ, and ITCZ prescribed to OC patients were effective against OC with respect to alleviation of OC symptoms.ConclusionMIC values of anti-fungal drugs against Candida strains isolated from OC patients were obtained and the 3 anti-fungal drugs given to OC patients were found to be effective against OC in spite of differences in their MIC values and in the number of resistant strains (or strains with a high MIC value).     

Profiling of differentially expressed genes in haemophilia A with inhibitor

Inhibitor development is the most significant complication in the therapy of haemophilia A (HA) patients. In spite of many studies, not much is known regarding the mechanism underlying inhibitor development. To understand the mechanism, we analysed profiles of differentially expressed genes (DEGs) between inhibitor and non-inhibitor HA via a microarray technique. Twenty unrelated Korean HAs were studied: 11 were non-inhibitor and nine were HA with inhibitor (≥5 BU mL(-1)). Microarray analysis was conducted using a Human Ref-8 expression Beadchip system (Illumina) and the data were analysed using Beadstudio software. We identified 545 DEGs in inhibitor HA as compared with the non-inhibitor patients; 384 genes were up-regulated and 161 genes were down-regulated. Among them, 75 genes whose expressions were altered by at least two-fold (>+2 or <-2) were selected and classified via the PANTHER classification method. The expressions of signal transduction and immunity-related genes differed significantly in the two groups. For validation of the DEGs, semi-quantitative RT-PCR (semi-qRT-PCR) was conducted with the six selected DEGs. The results corresponded to the microarray data, with the exception of one gene. We also examined the expression of the genes associated with the antigen presentation process via real-time PCR. The average levels of IL10, CTLA4 and TNFα slightly reduced, whereas that of IFNγ increased in the inhibitor HA group. We are currently unable to explain whether this phenomenon is a function of the inhibitor-inducing factor or is an epiphenomenon of antibody production. Nevertheless, our results provide a possible explanation for inhibitor development.     

白血病抑制因子与支气管哮喘

在支气管哮喘(简称哮喘)的发病过程中,机体神经、免疫与内分泌系统均参与其中,它是一个多步骤的过程,涉及到大量的细胞因子、炎症介质和神经递质.白血病抑制因子(leukemia inhibitory factor,LIF)是连接神经-免疫-内分泌系统网络的桥梁,LIF通过调节多种炎症细胞,如嗜酸粒细胞、淋巴细胞和肥大细胞等,促进炎性介质的释放;促进气道感觉神经末梢释放P物质等神经肽,上调气道上皮细胞神经激肽-1受体(neurokinin-1 receptor,NK-1R)的表达,诱发气道神经源性炎症;此外,LIF还可下调糖皮质激素受体的表达,导致糖皮质激素抵抗.因此LIF水平在哮喘患者血清、痰液、支气管肺泡灌洗液、支气管黏膜中均可有所升高.本文就LIF的生物学特征以及与哮喘发病的关系作一综述,旨在为探讨哮喘的发病机制和临床治疗提供理论依据.     

Somatostatin receptors: From signaling to clinical practice

Somatostatin is a peptide with a potent and broad antisecretory action, which makes it an invaluable drug target for the pharmacological management of pituitary adenomas and neuroendocrine tumors. Somatostatin receptors (SSTR1, 2A and B, 3, 4 and 5) belong to the G protein coupled receptor family and have a wide expression pattern in both normal tissues and solid tumors. Investigating the function of each SSTR in several tumor types has provided a wealth of information about the common but also distinct signaling cascades that suppress tumor cell proliferation, survival and angiogenesis. This provided the rationale for developing multireceptor-targeted somatostatin analogs and combination therapies with signaling-targeted agents such as inhibitors of the mammalian (or mechanistic) target of rapamycin (mTOR). The ability of SSTR to internalize and the development of rabiolabeled somatostatin analogs have improved the diagnosis and treatment of neuroendocrine tumors.     

Seasonal Effect of Gonadotrophin Inhibitory Hormone on Gonadotrophin‐Releasing Hormone‐induced Gonadotroph Functions in the Goldfish Pituitary

We have shown that native goldfish gonadotrophin inhibitory hormone (gGnIH) differentially regulates luteinsing hormone (LH)‐β and follicle‐stimulating hormone (FSH)‐β expression. To further understand the functions of gGnIH, we examined its interactions with two native goldfish gonadotrophin‐releasing hormones, salmon gonadotrophin‐releasing hormone (sGnRH) and chicken (c)GnRH‐II in vivo and in vitro. Intraperitoneal injections of gGnIH alone reduced serum LH levels in fish in early and mid gonadal recrudescence; this inhibition was also seen in fish co‐injected with either sGnRH or cGnRH‐II during early recrudescence. Injection of gGnIH alone elevated pituitary LH‐β and FSH‐β mRNA levels at early and mid recrudescence, and FSH‐β mRNA at late recrudescence. Co‐injection of gGnIH attenuated the stimulatory influences of sGnRH on LH‐β in early recrudescence, and LH‐β and FSH‐β mRNA levels in mid and late recrudescence, as well as the cGnRH‐II‐elicited increase in LH‐β, but not FSH‐β, mRNA expression at mid and late recrudescence. sGnRH and cGnRH‐II injection increased pituitary gGnIH‐R mRNA expression in mid and late recrudescence but gGnIH reduced gGnIH‐R mRNA levels in late recrudescence. gGnIH did not affect basal LH release from perifused pituitary cells and continual exposure to gGnIH did not alter the LH responses to acute applications of GnRH. However, a short 5‐min GnIH treatment in the middle of a 60‐min GnRH perifusion selectively reduced the cGnRH‐II‐induced release of LH. These novel results indicate that, in goldfish, gGnIH and GnRH modulate pituitary GnIH‐R expression and gGnIH differentially affects sGnRH and cGnRH‐II regulation of LH secretion and gonadotrophin subunit mRNA levels. Furthermore, these actions are manifested in a reproductive stage‐dependent manner.     

组蛋白去乙酰化酶抑制剂的合成及其体外抗肿瘤研究

目的设计并合成组蛋白去乙酰化酶抑制剂(HDACi),并对其组蛋白去乙酰化酶(HDACs)抑制活性和体外抗肿瘤活性进行研究。方法以N-Boc-对苯二胺和辛二酸酐为起始原料,反应制得7-(N-Boc-氨基)苯胺甲酰基庚酸,再通过胺醛缩合反应合成HDACi;并采用HDACs试剂盒和CCK-8试剂盒测试所合成目标化合物抑制HDACs的活性和抗肿瘤活性。结果合成了26个新化合物,其结构均经过核磁共振氢谱和质谱进行了确证。初步的生物活性测试结果表明,所合成的目标化合物对HDACs的抑制活性均强于阳性药物伏立诺他,并对MCF-7、PC-3、HepG2、MGC-803和KB 5种肿瘤细胞有不同程度的抑制活性,其中希夫碱含有吸电子基的化合物对HDACs的抑制活性以及抗肿瘤活性强于其他衍生物。尤其是4-氰基化合物11c对HDACs展现出了最强的抑制活性,是阳性药伏立诺他的58倍;同时,化合物11c对肿瘤细胞MCF-7、PC3、MGC-803和HepG2展现出了最强的抗肿瘤活性,其抗胃癌MGC-803甚至是阳性药物伏立诺他的7.2倍。结论希夫碱是一类重要的抗肿瘤药效团,能够提高HDACi的抗肿瘤活性,为今后发展新型、高效的HDACi提供了新的思路。