IL-6 and IL-10 Anti-Inflammatory Activity Links Exercise to Hypothalamic Insulin and Leptin Sensitivity through IKKβ and ER Stress Inhibition

Overnutrition caused by overeating is associated with insulin and leptin resistance through IKKβ activation and endoplasmic reticulum (ER) stress in the hypothalamus. Here we show that physical exercise suppresses hyperphagia and associated hypothalamic IKKβ/NF-κB activation by a mechanism dependent upon the pro-inflammatory cytokine interleukin (IL)-6. The disruption of hypothalamic-specific IL-6 action blocked the beneficial effects of exercise on the re-balance of food intake and insulin and leptin resistance. This molecular mechanism, mediated by physical activity, involves the anti-inflammatory protein IL-10, a core inhibitor of IKKβ/NF-κB signaling and ER stress. We report that exercise and recombinant IL-6 requires IL-10 expression to suppress hyperphagia-related obesity. Moreover, in contrast to control mice, exercise failed to reverse the pharmacological activation of IKKβ and ER stress in C3H/HeJ mice deficient in hypothalamic IL-6 and IL-10 signaling. Hence, inflammatory signaling in the hypothalamus links beneficial physiological effects of exercise to the central action of insulin and leptin.     

On the Origin of Microtubules’ High-Pressure Sensitivity

For over 50 years, it has been known that the mitosis of eukaryotic cells is inhibited already at high hydrostatic pressure conditions of 30 MPa. This effect has been attributed to the disorganization of microtubules, the main component of the spindle apparatus. However, the structural details of the depolymerization and the origin of the pressure sensitivity have remained elusive. It has also been a puzzle how complex organisms could still successfully inhabit extreme high-pressure environments such as those encountered in the depth of oceans. We studied the pressure stability of microtubules at different structural levels and for distinct dynamic states using high-pressure Fourier-transform infrared spectroscopy and Synchrotron small-angle x-ray scattering. We show that microtubules are hardly stable under abyssal conditions, where pressures up to 100 MPa are reached. This high-pressure sensitivity can be mainly attributed to the internal voids and packing defects in the microtubules. In particular, we show that lateral and longitudinal contacts feature different pressure stabilities, and they define also the pressure stability of tubulin bundles. The intactness of both contact types is necessary for the functionality of microtubules in vivo. Despite being known to dynamically stabilize microtubules and prevent their depolymerization, we found that the anti-cancer drug taxol and the accessory protein MAP2c decrease the pressure stability of microtubule protofilaments. Moreover, we demonstrate that the cellular environment itself is a crowded place and accessory proteins can increase the pressure stability of microtubules and accelerate their otherwise highly pressure-sensitive de novo formation.     

Aspartame Sensitivity? A Double Blind Randomised Crossover Study

Background

Aspartame is a commonly used intense artificial sweetener, being approximately 200 times sweeter than sucrose. There have been concerns over aspartame since approval in the 1980s including a large anecdotal database reporting severe symptoms. The objective of this study was to compare the acute symptom effects of aspartame to a control preparation.

Methods

This was a double-blind randomized cross over study conducted in a clinical research unit in United Kingdom. Forty-eight individual who has self reported sensitivity to aspartame were compared to 48 age and gender matched aspartame non-sensitive individuals. They were given aspartame (100mg)-containing or control snack bars randomly at least 7 days apart. The main outcome measures were acute effects of aspartame measured using repeated ratings of 14 symptoms, biochemistry and metabonomics.

Results

Aspartame sensitive and non-sensitive participants differed psychologically at baseline in handling feelings and perceived stress. Sensitive participants had higher triglycerides (2.05 ± 1.44 vs. 1.26 ± 0.84mmol/L; p value 0.008) and lower HDL-C (1.16 ± 0.34 vs. 1.35 ± 0.54 mmol/L; p value 0.04), reflected in ¹H NMR serum analysis that showed differences in the baseline lipid content between the two groups. Urine metabonomic studies showed no significant differences. None of the rated symptoms differed between aspartame and control bars, or between sensitive and control participants. However, aspartame sensitive participants rated more symptoms particularly in the first test session, whether this was placebo or control. Aspartame and control bars affected GLP-1, GIP, tyrosine and phenylalanine levels equally in both aspartame sensitive and non-sensitive subjects.

Conclusion

Using a comprehensive battery of psychological tests, biochemistry and state of the art metabonomics there was no evidence of any acute adverse responses to aspartame. This independent study gives reassurance to both regulatory bodies and the public that acute ingestion of aspartame does not have any detectable psychological or metabolic effects in humans.

Trial Registration

ISRCTN Registry ISRCTN39650237     

Sensitivity of ortho- and paramyxovirus replication to human interferon α

Replication of the influenza virus strains Influenza Ao/WSN (H0N1), fowl plague (Hav1N1) and B-Lee/40 (ATCC) and the paramyxovirus, New Castle disease virus (Victoria) are highly sensitive to human interfereon type in Madin Darby bovine kidney cells. Pretreatment of cells with human interferon type resulted in protection of the cells against viral cytopathic effect. The inhibition of the orthomyxovirus strains used in this study and New Castle disease virus replication is mediated by an inhibition of viral protein synthesis. Residual WSN virus particles released from interferon treated cells showed the same structural protein pattern as virus particles isolated from control cells. Glycosylation of the viral structural components appeared to be unaffected by interferon.     

MGMT Inhibition Restores ERα Functional Sensitivity to Antiestrogen Therapy

Antiestrogen therapy resistance remains a huge stumbling block in the treatment of breast cancer. We have found significant elevation of O(6) methylguanine DNA methyl transferase (MGMT) expression in a small sample of consecutive patients who have failed tamoxifen treatment. Here, we show that tamoxifen resistance is accompanied by upregulation of MGMT. Further we show that administration of the MGMT inhibitor, O(6)-benzylguanine (BG), at nontoxic doses, leads to restoration of a favorable estrogen receptor alpha (ERα) phosphorylation phenotype (high p-ERα Ser167/low p-ERα Ser118), which has been reported to correlate with sensitivity to endocrine therapy and improved survival. We also show BG to be a dual inhibitor of MGMT and ERα. In tamoxifen-resistant breast cancer cells, BG alone or in combination with antiestrogen (tamoxifen [TAM]/ICI 182,780 [fulvestrant, Faslodex]) therapy enhances p53 upregulated modulator of apoptosis (PUMA) expression, cytochrome C release and poly (ADP-ribose) polymerase (PARP) cleavage, all indicative of apoptosis. In addition, BG increases the expression of p21(cip1/waf1). We also show that BG, alone or in combination therapy, curtails the growth of tamoxifen-resistant breast cancer in vitro and in vivo. In tamoxifen-resistant MCF7 breast cancer xenografts, BG alone or in combination treatment causes significant delay in tumor growth. Immunohistochemistry confirms that BG increases p21(cip1/waf1) and p-ERα Ser167 expression and inhibits MGMT, ERα, p-ERα Ser118 and ki-67 expression. Collectively, our results suggest that MGMT inhibition leads to growth inhibition of tamoxifen-resistant breast cancer in vitro and in vivo and resensitizes tamoxifen-resistant breast cancer cells to antiestrogen therapy. These findings suggest that MGMT inhibition may provide a novel therapeutic strategy for overcoming antiestrogen resistance.     

MGMT Inhibition Restores ERα Functional Sensitivity to Antiestrogen Therapy

Antiestrogen therapy resistance remains a huge stumbling block in the treatment of breast cancer. We have found significant elevation of O⁶ methylguanine DNA methyl transferase (MGMT) expression in a small sample of consecutive patients who have failed tamoxifen treatment. Here, we show that tamoxifen resistance is accompanied by upregulation of MGMT. Further we show that administration of the MGMT inhibitor, O⁶-benzylguanine (BG), at nontoxic doses, leads to restoration of a favorable estrogen receptor alpha (ERα) phosphorylation phenotype (high p-ERα Ser167/low p-ERα Ser118), which has been reported to correlate with sensitivity to endocrine therapy and improved survival. We also show BG to be a dual inhibitor of MGMT and ERα. In tamoxifen-resistant breast cancer cells, BG alone or in combination with antiestrogen (tamoxifen [TAM]/ICI 182,780 [fulvestrant, Faslodex]) therapy enhances p53 upregulated modulator of apoptosis (PUMA) expression, cytochrome C release and poly (ADP-ribose) polymerase (PARP) cleavage, all indicative of apoptosis. In addition, BG increases the expression of p21^cip1/waf1. We also show that BG, alone or in combination therapy, curtails the growth of tamoxifen-resistant breast cancer in vitro and in vivo. In tamoxifen-resistant MCF7 breast cancer xenografts, BG alone or in combination treatment causes significant delay in tumor growth. Immunohistochemistry confirms that BG increases p21^cip1/waf1 and p-ERα Ser167 expression and inhibits MGMT, ERα, p-ERα Ser118 and ki-67 expression. Collectively, our results suggest that MGMT inhibition leads to growth inhibition of tamoxifen-resistant breast cancer in vitro and in vivo and resensitizes tamoxifen-resistant breast cancer cells to antiestrogen therapy. These findings suggest that MGMT inhibition may provide a novel therapeutic strategy for overcoming antiestrogen resistance.     

IL-1，IL-6，IL-8 与胃癌的关系

胃癌是常见的恶性肿瘤之一,在我国其发病率居各类肿瘤前列,导致的死亡人数占所有肿瘤的四分之一,而且每年有近40万新增的胃癌病人,但是其早期诊断率低于20%,胃癌已经成为危害人民健康的最严重的疾病之一。白细胞介素(interleukin,IL)作为在白细胞或免疫细胞间相互作用的淋巴因子,不仅在介导T、B细胞活化、增殖与分化以及炎症反应中起着重要作用,近年来,越来越多的学者发现其与肿瘤的发生及发展也有着密不可分的联系。目前为止,已经发现了29种白细胞介素,分别被命名为IL-1~IL-29,它们各自承担着相应的使命。国内外大量实验及文献表明,IL-1,IL-6,IL-8和胃癌有着密切的关系,这对于胃癌的早期诊断及治疗提出了新的思路,进而提高胃癌的早期诊断率,改善胃癌的治疗状况。本文对IL-1,IL-6,IL-8的来源、分子结构及受体方面进行简要概述,同时阐述了其生物学特性及与胃癌的关系。     

IL-39:IL-12家族的新成员

白细胞介素-39(interleukin,IL-39)是最近发现的IL-12家族新成员,由IL-23p19和EB病毒诱导基因3两个亚基组成。它主要由脂多糖刺激的B细胞和狼疮小鼠体内活化的GL7~+B细胞产生,IL-23R/gp130为其受体,在狼疮小鼠体内通过激活信号转导与转录激活因子1(STAT1)/STAT3信号通路介导炎症反应。因此,深入研究IL-39的结构、信号通路以及生物学功能,对系统性红斑狼疮和其它自身免疫性疾病的治疗具有重要价值。     

Sensitivity of Intracellular Bacteriophage λ to Colicin CA42-E2

Treatment of Escherichia coli K-12 infected by lambda CIts857 with colicin CA42-E2 resulted in partial inhibition of the infectious process. Uninfected bacteria were killed by colicin with a probability of about five times that with which similarly treated lambda-infected bacteria lose plaque-forming ability. The lambda deoxyribonucleic acid (DNA), when present in a bacterial cell either as the replicating DNA of infectious phage or as the nonreplicating DNA of superinfecting phage, was degraded to acid-soluble material after colicin treatment. Analysis of the intermediates of DNA breakdown has revealed that degradation of the DNA to acid-soluble material is preceded by endonucleolytic fragmentation of the chromosome at a limited number of sites. This is the same mechanism of degradation previously observed for E. coli DNA after colicin treatment.     

What Is the Primary Cause of Individual Differences in Contrast Sensitivity?

One of the primary objectives of early visual processing is the detection of luminance variations, often termed image contrast. Normal observers can differ in this ability by at least a factor of 4, yet this variation is typically overlooked, and has never been convincingly explained. This study uses two techniques to investigate the main source of individual variations in contrast sensitivity. First, a noise masking experiment assessed whether differences were due to the observer’s internal noise, or the efficiency with which they extracted information from the stimulus. Second, contrast discrimination functions from 18 previous studies were compared (pairwise, within studies) using a computational model to determine whether differences were due to internal noise or the low level gain properties of contrast transduction. Taken together, the evidence points to differences in contrast gain as being responsible for the majority of individual variation across the normal population. This result is compared with related findings in attention and amblyopia.     

IL-1β Suppresses Innate IL-25 and IL-33 Production and Maintains Helminth Chronicity

Approximately 2 billion people currently suffer from intestinal helminth infections, which are typically chronic in nature and result in growth retardation, vitamin A deficiency, anemia and poor cognitive function. Such chronicity results from co-evolution between helminths and their mammalian hosts; however, the molecular mechanisms by which these organisms avert immune rejection are not clear. We have found that the natural murine helminth, Heligmosomoides polygyrus bakeri (Hp) elicits the secretion of IL-1β in vivo and in vitro and that this cytokine is critical for shaping a mucosal environment suited to helminth chronicity. Indeed in mice deficient for IL-1β (IL-1β^−/−), or treated with the soluble IL-1βR antagonist, Anakinra, helminth infection results in enhanced type 2 immunity and accelerated parasite expulsion. IL-1β acts to decrease production of IL-25 and IL-33 at early time points following infection and parasite rejection was determined to require IL-25. Taken together, these data indicate that Hp promotes the release of host-derived IL-1β that suppresses the release of innate cytokines, resulting in suboptimal type 2 immunity and allowing pathogen chronicity.     

IL-17、IL-8、IL-10水平与早期糖尿病肾病的关系

目的观察糖尿病大鼠肾脏早期IL-17、IL-8、IL-10水平的变化,并分析糖尿病大鼠肾脏早期IL-17、IL-8、IL-10水平与糖尿病肾病的关系。方法健康雄性SD大鼠被随机分为正常对照组和糖尿病模型组,模型组以一次性腹腔注射STZ诱导糖尿病模型;造模成功后在1周、2周、4周、6周,12周时间点分别取两肾,称量两肾的重量及大鼠体重,常规方法检测血清生化指标和尿蛋白含量,ELISA检测IL-17、IL-8、IL-10水平。分析IL-17、IL-8、IL-10水平与糖尿病肾病的关系。结果糖尿病各组大鼠IL-17、IL-8随时间逐渐升高,IL-10随时间逐渐降低,IL-17、IL-8与血糖、CRP、肾脏肥大指数、24小时尿蛋白、肌酐、血尿素氮呈正相关,IL-10与血糖、CRP、肾脏肥大指数、24小时尿蛋白、肌酐、血尿素氮呈负相关,IL-17、IL-8与IL-10呈负相关。结论 IL-17、IL-8可能促进糖尿病大鼠肾病的发展,IL-10可能抑制糖尿病大鼠肾病的进展。     

IL-23和IL-17在结核病中的研究进展

近年来结核病的发病率越来越高,随着对结核病免疫机制的进一步研究,发现了Th17、IL-23、IL-17在结核免疫保护中起着重要作用。对这免疫途径的研究有利于进一步阐明结核病的免疫机制和指导临床诊疗。     

不同镇痛方法对患者IL-6、IL-8、IL-10的影响

目的评价不同镇痛方法对盆腔手术患者血浆中细胞因子变化的影响,并与传统术后镇痛法进行比较,探讨术后充分镇痛对免疫功能的影响。方法根据镇痛方法不同,将60例行子宫切除患者随机分为3组：第1组患者为术后根据临床需要,临时给予哌替啶50mg肌肉注射（Ⅰ组,n=20）;第Ⅱ组患者为罗哌卡因复合芬太尼硬膜外镇痛组（Ⅱ组,n=20）;第Ⅲ组患者为芬太尼静脉镇痛组（Ⅲ组,n=20）;观察麻醉前30min、手术后30min、2h、24h、48h和72h六个时点患者血清中白细胞介素-6（IL-6）、白细胞介素-8（IL-8）、白细胞介素-10（IL-10）水平的变化。结果3组患者术后血清IL-6、IL-8、IL-10水平与麻醉前值比较均升高（P〈0．01）,一般在术后24h达峰值。比较血清IL-6、IL-8、IL-10浓度变化,Ⅱ和Ⅲ组抑制这3种细胞因子释放的能力明显强于Ⅰ组（P〈0．05）,与Ⅲ组比较,Ⅱ组更为明显（P〈0．05）。结论硬膜外局麻药复合阿片受体激动药镇痛模式可更有效地降低术后炎性直激反应。     

应用基因工程技术生产IL-11和IL-12

目前武汉大学生命科学学院科研人员针对人体失血和免疫功能下降,应用基因工程技术生产出了人白细胞介素-11(即IL-11)和人白细胞介素-12(即IL-12)。 1 IL-11为人体自然产生的细胞生长因子,能增加血小板,提高凝血速度,防止伤口出血不止,在临床上用来治疗低血小板症,还能辅助治疗癌症,主要用于化疗。克隆于载体,通过大肠杆菌充分表达,经分离、纯化和精制,生产出质量很高的医用成药,故疗效很好。 2 IL-12这是目前在细胞素中发现对人体免疫活性细胞诱导和调节最强、范围最广的一种。其研制技术是将IL-12的两种不同来源的基因克隆于昆虫病毒载体,在昆虫细胞内表达,经分离纯化成工程蛋白,再制备成医药产品。它能诱导干扰素的产生,激活T细胞和NK细胞产生肿瘤坏死因子,能抗利什曼原虫、疟原虫、结核杆菌、血吸虫、肿瘤和病毒及其各相应的疾病,故美国基因研究所和惠施-阿耶斯特制药公司将它用于治疗艾滋病和肿瘤病,效果很好。秦春圃     

What Can We Learn from Global Sensitivity Analysis of Biochemical Systems?

Most biological models of intermediate size, and probably all large models, need to cope with the fact that many of their parameter values are unknown. In addition, it may not be possible to identify these values unambiguously on the basis of experimental data. This poses the question how reliable predictions made using such models are. Sensitivity analysis is commonly used to measure the impact of each model parameter on its variables. However, the results of such analyses can be dependent on an exact set of parameter values due to nonlinearity. To mitigate this problem, global sensitivity analysis techniques are used to calculate parameter sensitivities in a wider parameter space. We applied global sensitivity analysis to a selection of five signalling and metabolic models, several of which incorporate experimentally well-determined parameters. Assuming these models represent physiological reality, we explored how the results could change under increasing amounts of parameter uncertainty. Our results show that parameter sensitivities calculated with the physiological parameter values are not necessarily the most frequently observed under random sampling, even in a small interval around the physiological values. Often multimodal distributions were observed. Unsurprisingly, the range of possible sensitivity coefficient values increased with the level of parameter uncertainty, though the amount of parameter uncertainty at which the pattern of control was able to change differed among the models analysed. We suggest that this level of uncertainty can be used as a global measure of model robustness. Finally a comparison of different global sensitivity analysis techniques shows that, if high-throughput computing resources are available, then random sampling may actually be the most suitable technique.     

Does Recall after Sleep-Dependent Memory Consolidation Reinstate Sensitivity to Retroactive Interference?

Previous studies have shown that newly encoded memories are more resistant to retroactive interference when participants are allowed to sleep after learning the original material, suggesting a sleep-related strengthening of memories. In the present study, we investigated delayed, long-term effects of sleep vs. sleep deprivation (SD) on the first post-training night on memory consolidation and resistance to interference. On day 1, participants learned a list of unrelated word pairs (AB), either in the morning or in the evening, then spent the post-training night in a sleep or sleep deprivation condition, in a within-subject paradigm. On day 4, at the same time of day, they learned a novel list of word pairs (AC) in which 50% of the word pairs stemmed with the same word than in the AB list, resulting in retroactive interference. Participants had then to recall items from the AB list upon presentation of the “A” stem. Recall was marginally improved in the evening, as compared to the morning learning group. Most importantly, retroactive interference effects were found in the sleep evening group only, contrary to the hypothesis that sleep exerts a protective role against intrusion by novel but similar learning. We tentatively suggest that these results can be explained in the framework of the memory reconsolidation theory, stating that exposure to similar information sets back consolidated items in a labile form again sensitive to retroactive interference. In this context, sleep might not protect against interference but would promote an update of existing episodic memories while preventing saturation of the memory network due to the accumulation of dual traces.     

Integrative “Omic” Analysis for Tamoxifen Sensitivity through Cell Based Models

It has long been observed that tamoxifen sensitivity varies among breast cancer patients. Further, ethnic differences of tamoxifen therapy between Caucasian and African American have also been reported. Since most studies have been focused on Caucasian people, we sought to comprehensively evaluate genetic variants related to tamoxifen therapy in African-derived samples. An integrative “omic” approach developed by our group was used to investigate relationships among endoxifen (an active metabolite of tamoxifen) sensitivity, SNP genotype, mRNA and microRNA expressions in 58 HapMap YRI lymphoblastoid cell lines. We identified 50 SNPs that associate with cellular sensitivity to endoxifen through their effects on 34 genes and 30 microRNA expression. Some of these findings are shared in both Caucasian and African samples, while others are unique in the African samples. Among gene/microRNA that were identified in both ethnic groups, the expression of TRAF1 is also correlated with tamoxifen sensitivity in a collection of 44 breast cancer cell lines. Further, knock-down TRAF1 and over-expression of hsa-let-7i confirmed the roles of hsa-let-7i and TRAF1 in increasing tamoxifen sensitivity in the ZR-75-1 breast cancer cell line. Our integrative omic analysis facilitated the discovery of pharmacogenomic biomarkers that potentially affect tamoxifen sensitivity.