Islet-1 在乙酰化调控网络中特异性辅助C3H10T1/2细胞向心肌样细胞分化

 目的 筛选并分析转染Islet-1慢病毒载体的C3H10T1/2细胞转化为心肌样细胞过程中与Islet-1 相互作用的组蛋白乙酰化酶（HATs）和组蛋白去乙酰化酶（HDACs）,明确Islet-1在C3H10T1/2细胞分化为心肌样细胞乙酰化调控网络中的关键枢纽作用。方法 培养转染Islet-1慢病毒载体的C3H10T1/2细胞,观察细胞形态。免疫荧光和免疫印迹检测Islet-1的表达部位和最高表达时间点。免疫共沉淀沉淀与Islet-1结合的蛋白。免疫印迹验证Islet-1 相互作用的HATs和HDACs。结果 诱导组细胞形态出现心肌样细胞改变。各组Islet-1主要在胞浆表达。诱导组Islet-1表达量在诱导后3周最高（0.782±0.015）。诱导组Islet-1表达量显著高于空白对照组和C3H10组（分别为0.819±0.026,0.127±0.006和0.126±0.001）（P<0.05）,免疫共沉淀技术可行。与Islet-1相互作用的HATs和HDACs有GCN5、P300/CBP和HDAC4。结论 Islet-1 与GCN5、P300/CBP和HDAC4相互作用特异性辅助C3H10T1/2细胞向心肌样细胞分化。     

Global histone modification pattern associated with recurrence and disease-free survival in non-small cell lung cancer patients

Global histone modification patterns are presumed to establish epigenetic patterns of gene expression and determine the biology of the cell. In the present study, the global modification status of histone H3 and H4 was evaluated in 408 non-small cell lung cancer (NSCLC) tissues by immunostaining. NSCLC showed variable staining scores for each antibody. Clinicopathological analyses demonstrated a positive correlation between weak nuclear staining for H3K9Ac (P < 0.001), H3K9TriMe (P= 0.001), H4K16Ac (P < 0.001) and tumor recurrence except H4K20 TriMe (P= 0.201). Staining scores of four different antibodies were not correlated with other clinicopathologic variables. Patients were further clustered according to histone modification patterns: acetylation dominant, methylation dominant, co-dominant and modification-negative. The acetylation-dominant group (P= 0.009) and co-dominant group exhibited less frequent lymph node metastasis (P= 0.050), recurrence (P= 0.002) and distant metastasis (P= 0.010). The acetylation-dominant group showed better prognosis in survival analysis (P < 0.001, log-rank), whereas methylation-dominant and modification-negative status was associated with poor prognosis. In conclusion, our data suggest that global histone H3 and H4 modification patterns are potential markers of tumor recurrence and disease-free survival in NSCLC patients.     

三氧化二砷对MRL/lpr狼疮鼠IFN-γ基因表达的调控

目的: 探讨三氧化二砷(ATO)调控MRL/lpr狼疮鼠干扰素γ(IFN-γ)基因表达的机制。方法: 将20周龄MRL/lpr狼疮鼠和正常C57BL/6J小鼠无菌条件下取出脾脏,制成脾脏淋巴细胞悬液。体外经植物血球凝集素P(PHA-P,终浓度20 mg/L)和白细胞介素-2(IL-2,终浓度10⁶ IU/L)常规刺激48 h后,随机分为PBS组(空白对照)和 ATO(1.0 μmol/L)组,继续培养24 h。酶联免疫吸附法(ELISA)测定各组培养上清液IFN-γ的表达量,采用实时荧光定量PCR(Q-PCR)检测各组IFN-γ mRNA的表达情况,应用基于半定量PCR和Q-PCR的染色质免疫共沉淀(ChIP)技术检测各组细胞 IFN-γ 启动子区乙酰化组蛋白H3、H4(acH3, acH4)及启动子区结合RNA聚合酶Ⅱ(RNAPⅡ)的水平。结果: (1)MRL/lpr狼疮鼠PBS组IFN-γ的分泌和IFN-γ mRNA的表达均高于C57BL/6J小鼠PBS组(分别P<0.01和 P<0.05),并且 IFN-γ 启动子区acH3、acH4的水平及启动子区域富集RNAPⅡ水平高于C57BL/6J小鼠PBS组(均P<0.01)。(2)在MRL/lpr狼疮鼠中,与PBS组相比,ATO组IFN-γ的分泌和IFN-γ mRNA的表达下降(分别P<0.01, P<0.05),IFN-γ基因启动子区域acH3、acH4的水平及启动子区域富集RNAPⅡ水平也下降(均P<0.01)。(3)在C57BL/6J小鼠中,PBS组和ATO组之间以上指标均无差异。结论: ATO下调MRL/lpr狼疮鼠IFN-γ的分泌和IFN-γ mRNA的表达可能是通过降低基因启动子区域acH3、acH4的水平减弱了RNAPⅡ依赖的转录,而ATO对正常C57BL/6J小鼠无明显影响。     

hMOF蛋白在子宫内膜癌组织中的表达及临床意义

目的探讨hMOF（human male absent on the first）蛋白在子宫内膜癌组织中的表达及临床意义。方法采用免疫组织化学（IHC）的方法检测58例子宫内膜癌组织（子宫内膜癌WTO分级G1级20例,G2级18例,G3级20例）及癌旁正常组织的hMOF蛋白的表达水平,并与临床及病理资料进行分析比较,统计学方法采用单因素多元方差分析及Fisher检验明确hMOF蛋白表达水平与子宫内膜癌患者临床病例特点的关系。结果免疫组织化学显示：hMOF蛋白在23例（39.6%）子宫内膜癌组织中的表达为阴性或弱阳性,癌旁正常组织仅5例（13.1%）表达为阴性或弱阳性,两组有显著差异（P〈0.05）。根据IHC评分将患者分为≤4分组和≥5分组,比较两组间患者的临床特点：≤4分组中,子宫内膜癌为低分化（G3级）的病例占52.1%（12/23）,FIGO分级为Ⅲ-Ⅳ级的病例占47.8%（11/23）;≥5分组中G3病例仅占22.8%（8/35）,FIGO分级为Ⅲ-Ⅳ级的病例占14.3%,两组间差异显著（P〈0.05）。结论 hMOF蛋白在子宫内膜癌组织,尤其低分化、高分期的子宫内膜癌组织中的表达明显下降。这提示hMOF蛋白可能在子宫内膜癌的发生发展中起到重要作用,hMOF蛋白可以作为一个判断子宫内膜癌疾病严重程度和预后的生物分子指标。     

Pharmacology of epigenetics in brain disorders

Epigenetics is a rapidly growing field and holds great promise for a range of human diseases, including brain disorders such as Rett syndrome, anxiety and depressive disorders, schizophrenia, Alzheimer disease and Huntington disease. This review is concerned with the pharmacology of epigenetics to treat disorders of the epigenome whether induced developmentally or manifested/acquired later in life. In particular, we will focus on brain disorders and their treatment by drugs that modify the epigenome. While the use of DNA methyl transferase inhibitors and histone deacetylase inhibitors in in vitro and in vivo models have demonstrated improvements in disease-related deficits, clinical trials in humans have been less promising. We will address recent advances in our understanding of the complexity of the epigenome with its many molecular players, and discuss evidence for a compromised epigenome in the context of an ageing or diseased brain. We will also draw on examples of species differences that may exist between humans and model systems, emphasizing the need for more robust pre-clinical testing. Finally, we will discuss fundamental issues to be considered in study design when targeting the epigenome.     

Epigenetic enhancement of p66Shc during cellular replicative or premature senescence

The cytoplasmic protein p66Shc is expressed in a wide range of cell types, initially believed to be involved in signaling pathways that regulate cell growth and oxidative stress. Here the epigenetic alterations in the promoter of p66Shc were investigated in replicative senescence and in premature senescence induced by hydrogen peroxide in human embryonic pulmonary fibroblast cells. In both cases p66Shc expression was elevated compared to that seen in growing cultures. However, methylation-specific PCR and bisulfite sequencing revealed that the CpG sites were hypermethylated in all cultures. In addition, quantitative chromatin immunoprecipitation showed increased histone H4 acetylation and histone H3 Lys-4 methylation during replicative senescence, while the increased acetylation of histone H3 and H4, as well as increased H3 Lys-4 methylation, was seen in premature senescence persistence. These findings suggest that histone modifications of p66Shc might be the molecular event in cellular senescence. Taken together, the epigenetic enhancement of p66Shc is associated with the specifically increased histone acetylation and methylation, which may contribute to cellular replicative senescence or premature senescence.     

多糖化学结构修饰方法的研究进展

多糖是一类重要的生物大分子物质,具有抗肿瘤、抗病毒、抗氧化、免疫活性调节等生物活性。多糖的生物活性与其结构有直接关系,因而对多糖结构通过适当的方法进行修饰是目前多糖领域研究的重要方向之一。简要地阐述多糖的化学修饰方法（包括硫酸化、羧甲基化、乙酰化和磷酸化等）研究进展,以及修饰后对生物活性的影响,以期为新药发现提供依据。