曲古抑素A对耐顺铂人肺腺癌细胞株凋亡影响及其机制的探讨

目的:探讨曲古抑素A(TSA)诱导耐顺铂(DDP)人肺腺癌A549/DDP细胞株凋亡的作用及机制。方法:荧光染色检测细胞凋亡,蛋白质印迹法分析cFLIP、Caspase-8、Caspase-3和聚腺苷二磷酸核糖聚合酶(PARP)蛋白表达的变化,同时比色法测定Caspase-8活性。结果:曲古抑素A能诱导凋亡A549/DDP细胞株凋亡,随着浓度增加,其凋亡率逐渐增加。蛋白质印迹法结果显示,TSA处理细胞后,cFLIP蛋白水平下降,Pro-caspase-8减少,提示该酶被激活,促使Bid蛋白切割。Procaspase-3减少,提示酶被激活。PARP蛋白减少,切割的条带逐渐增加,提示PARP活性增加,促进细胞凋亡。比色法结果显示TSA对Caspase-8活性和cFLIP的影响具有浓度和时间依赖性。结论:TSA可以通过降低cFLIP水平激活Caspase-8诱导A549/DDP细胞凋亡。     

Pharmacodynamics of curcumin as DNA hypomethylation agent in restoring the expression of Nrf2 via promoter CpGs demethylation

Prostate cancer (PCa) is one of the most deadly malignancies among men in the United States. Although localized prostate cancer can be effectively treated via surgery or radiation, metastatic disease is usually lethal. Recent evidence suggests that the development and progression of human prostate cancer involves complex interplay between epigenetic alterations and genetic defects. We have recently demonstrated that Nrf2, a master regulator of cellular antioxidant defense systems, was epigenetically silenced during the progression of prostate tumorigenesis in TRAMP mice. The aim of this study is to investigate the potential of curcumin (CUR), a dietary compound that we have reported to be able to prevent the development of prostate cancer in TRAMP mice, as a DNA hypomethylation agent. Using bisulfite genomic sequencing (BGS), treatment of TRAMP C1 cells we showed that CUR reversed the methylation status of the first 5 CpGs in the promoter region of the Nrf2 gene. Methylation DNA immunoprecipitation (MeDIP) analysis revealed that CUR significantly reduced the anti-mecyt antibody binding to the first 5 CpGs of the Nrf2 promoter, corroborated the BGS results. Demethylation of Nrf2 was found to be associated with the re-expression of Nrf2 and one of its downstream target gene, NQO-1, one of the major anti-oxidative stress enzymes, both at the mRNA and protein levels. Taken together, our current study suggests that CUR can elicit its prostate cancer chemopreventive effect, potentially at least in part, through epigenetic modification of the Nrf2 gene with its subsequent induction of the Nrf2-mediated anti-oxidative stress cellular defense pathway.     

组蛋白去乙酰化调控软骨细胞Ⅱ型胶原表达的机理研究

目的　探讨通过TSA抑制组蛋白去乙酰化水平,研究组蛋白去乙酰化对软骨细胞表型相关基因的影响及其机制,从表观遗传学角度为维持软骨细胞表型提供新的思路。 方法 体外培养人关节软骨细胞,建立软骨细胞去分化模型,采用不同浓度TSA刺激,在不同时间点收集细胞,提取总RNA,利用qRT-PCR检测Wnt-5a、SOX-9、COL-Ⅱ、COL-Ⅰ的mRNA表达情况。利用免疫荧光及Westerblot进行COL-Ⅱ蛋白表达水平的检测。 结果　与对照组比较,TSA（0.25~1.0 μmol/L）显著降低COL-Ⅱ mRNA表达水平及蛋白表达水平,升高Wnt-5a 和SOX-9 mRNA表达水平;抑制Wnt-5a信号通路减弱TSA 对COL-Ⅱ的抑制效应。 结论 TSA通过激活Wnt-5a和 SOX-9从而抑制COL-Ⅱ的表达,导致软骨细胞表型丧失。因此,组蛋白去乙酰化通过降低Wnt-5a和SOX-9,升高COL-Ⅱ的表达水平,发挥维持软骨细胞表型的作用。     

Le syndrome d’évitement pathologique des demandes : psychopathie autistique ? Syndrome d’Asperger ? Autisme atypique ? Ou trouble envahissant du développement (TED) spécifique ?

The aim of this paper is to inform French clinicians about “pathological demand avoidance” syndrome, also referred to as PDA, described by Elizabeth Newson (1929–2014), professor of developmental psychology at the University of Nottingham in the 1980s. E. Newson discerned a particular behavioral pattern in a subgroup of children who were referred to her for suspicion of autism or Asperger's syndrome without confirmed diagnostic assessment. These children have an inability to tolerate demands imposed upon them and try to resist with strategies of avoidance; being essentially socially manipulative is not compatible with the shared representation of autism. They give an impression of sociability, but they often lack a sense of social identity (e.g. believing themselves to be on a par with or superior to adults), pride or shame. They have mood swings led by need to control their relationship. They appear comfortable in role playing and pretending – often adopting borrowed roles when interacting with others (e.g. relating to peers in the manner of a teacher). In recent years, PDA has attracted increasing clinical attention mainly in the United Kingdom and Northern Europe, but little is known in France. Its validity as well as its place in the nosography are still being debated. E. Newson considered PDA to be a specific pervasive developmental disorder while other clinicians classified it in autism spectrum disorders (ASD). It remains true that PDA is a real clinical problem that imposes a therapeutic challenge: the need for these subjects to control the relationship makes it very difficult to treat. In this article, we illustrate the cardinal signs of this syndrome with a clinical case to facilitate its recognition. We discuss two differential diagnoses: oppositional defiant disorder and ASD. We found that the autistic psychopathy described by Hans Asperger resembles PDA. The interest of E. Newson's work is to highlight the affective and emotional presentation of the symptoms not described in DSM-5 which only emphasizes the deficits of social cognition (deficits in socio-emotional reciprocity, non-verbal communication, restricted interests etc.). Educational approaches effective for PDA differ from “typical” ASD and include novelty, humor and flexibility.     

Timing is everything: Order of administration of 5-aza 2′ deoxycytidine,trichostatin A and tamoxifen changes estrogen receptor mRNA expression and cell sensitivity

Restoration of estrogen receptor (ER) expression using epigenetic inhibitors re-establishes expression of the estrogen receptor (ER) and restores tamoxifen sensitivity in ER negative breast cancer cells. We tested if order of administration of the DNMT (5-aza 2′ deoxycytidine/AZA) or HDAC (trichostatin A/TSA) inhibitors and tamoxifen affected ER re-expression and tamoxifen sensitivity. Treatment with AZA followed by co-administration of TSA plus tamoxifen resulted in the greatest ER re-expression and tamoxifen sensitivity, although sensitivity was not increased as robustly as expected. This could be due to increased cytoplasmic levels of HuR, suggesting that cytoplasmic HuR levels are central to tamoxifen responsiveness.     

TSA诱导人肝癌HepG2细胞凋亡及对FHIT表达的影响

[目的]研究去乙酰化转移酶抑制剂TSA对人肝癌HepG2细胞的作用及其FHIT表达的影响。[方法]培养的人肝癌HepG2细胞随机分为两组:对照组给予等量DMSO,实验组给予终浓度分别为125、250、500、1 000、2 000nmol/L的TSA,培养24 h后收集细胞,MTT比色法检测细胞活性,TUNEL法检测细胞凋亡率,逆转录聚合酶链反应(RT-PCR)和免疫细胞化学检测FHIT的mRNA和蛋白表达水平。[结果]与对照组相比,经TSA处理的细胞增殖速度明显减慢,TUNEL阳性细胞百分率随TSA浓度的升高呈剂量依赖性增高(P﹤0.01),细胞FHIT mRNA表达增强(P﹤0.01),FHIT蛋白表达差异具有统计学意义(P﹤0.01)。[结论]TSA可能通过抑制HDACs的活性,上调FHIT表达,诱导细胞凋亡而抑制肝癌细胞生长。     

Comorbidité TDA/H (Trouble du Déficit de l’Attention avec ou sans Hyperactivité) et TSA (Troubles du Spectre autistique)

The publication of the fifth version of the DSM in May 2013 officially recognized comorbidity between Attention-Deficit Disorder with or without Hyperactivity (ADD/ADHD) and Autism Spectrum Disorders (ASD). Indeed, the DSM-IV didn’t allow concomitant diagnosis. However, there is a clinical, neuropsychological and genetic overlap between these two disorders. Thus, 30–80 % of patients with ASD fill criteria for ADD/ADHD and in 20–50 % of patients with ADD/ADHD are found the diagnostic criteria for ASD. These observations raise the question of the link between ADD/ADHD and ASD: Is ADD/ADHD a minor form of ASD? Are ASD and ADD/ADHD different manifestations from a single neurodevelopmental disorder? Finally, are they two distinct developmental disorders whose clinical expressions would approach? Recent studies seem to distinguish two types of situations: Comorbid patients with less severe symptoms of ASD do not differ qualitatively from ADD/ADHD patients alone, which argues for a continuum between ADD/ADHD and ASD. Patients with ASD symptoms predominate are qualitatively different subjects from ADD/ADHD alone, thus corresponds to the hypothesis of two distinct nosological entities. Anyway, when ADD/ADHD and ASD are associated, there are specific clinical expression of developmental pathways and prognosis. Thus, these comorbid patients suffer more frequently from other psychiatric disorders, have a poorer quality of life, poorer adaptive functioning and clinical expression is more persistent over time. The modalities of treatment of comorbid patients may associate psychoeducational, psychotherapeutic approaches and medication (methylphenidate, atomoxetine, guanfacine, risperidone, aripiprazole).     

曲古抑菌素A在体细胞核移植中的应用

体细胞核移植(SCNT)技术已成功获得多种哺乳动物的克隆后代,但一直以来克隆的成功率都很低,并且存活个体大多表型异常.研究表明,重构胚的重编程不完全是导致克隆动物存活率低下和发育异常的主要原因之一.DNA甲基化、组蛋白乙酰化都是影响重编程的重要因素,曲古抑菌素A(TSA)是链霉素的代谢产物,同时也是一种组蛋白去乙酰化酶抑制剂,能降低DNA甲基化水平,促进重编程率,进而提高克隆效率.本文对TSA的生物学功能及其在动物SCNT中的应用进行了探究.