曲古抑菌素A体内外杀伤卵巢癌细胞

目的 探讨组蛋白去乙酰化酶(HDAC)抑制剂曲古抑菌素A(TSA)在卵巢癌靶向治疗中的作用及机制.方法 以2种正常卵巢上皮细胞系IOSE-29和IOSE-329及3种卵巢癌细胞系ES-2、SKOV-3和OVCAR-8为研究对象,应用XTT法和流式细胞术检测TSA对卵巢癌细胞的抗增殖及诱导凋亡作用,并观察其体内疗效.结果 对比正常卵巢上皮,卵巢癌及其细胞系中HDAC6蛋白呈强阳性表达,其抑制剂TSA对ES-2,SKOV-3和OVCAR-8卵巢癌细胞系有明显杀伤作用,但正常卵巢上皮细胞对TSA不敏感,TSA处理组的卵巢癌细胞凋亡率和死亡率较未处理组高.体内实验表明:TSA处理组的ES-2裸鼠体内移植瘤生长速度较未处理组慢.结论 TSA可在体内外有效杀伤卵巢癌细胞,其机制部分是通过抑制HDAC6而实现的.     

曲古抑菌素A通过抑制脊髓背角内的炎症反应减轻大鼠神经病理性痛

目的:观察曲古抑菌素A (TSA)对脊神经结扎(SNL)大鼠镇痛效果及分子机制。方法:40只健康雄性Sprague Dawley(SD)大鼠随机分为假手术组(sham)、曲古抑菌素A处理组(TSA)、脊神经结扎组(SNL)和SNL+TSA组(SNL+TSA)。采用L5脊神经结扎(SNL)的方法建立神经病理性痛模型,鞘内注射TSA进行干预,通过von Frey丝和热板实验检测大鼠的痛敏,应用免疫荧光染色方法观察大鼠脊髓背角内HDAC1的表达情况;应用Western Blot方法观察大鼠脊髓背角内胶质纤维酸性蛋白(GFAP)和离子钙接头蛋白分子1(Iba-1)的表达水平;应用real time RT-PCR方法检测大鼠脊髓背角内TNF-α、IL-1β和IL-6的mRNA表达水平。结果:SNL模型大鼠术后机械性痛阈值和热痛阈值均显著降低(P <0.05),鞘内给予TSA能够明显缓解大鼠患侧后足机械性痛敏和热痛敏; SNL模型大鼠脊髓背角内HDAC1的表达较对照组明显增加,而鞘内注射TSA可显著抑制其表达; SNL术后脊髓背角内GFAP和Iba-1的表达显著升高(P <0.05),...     

曲古抑菌素A通过调控蛋白激酶C促进食管鳞癌细胞迁移

目的探讨组蛋白去乙酰化酶抑制剂曲古抑菌素A(TSA)对人食管鳞癌细胞(ESCC)迁移能力的影响及其可能的作用机制。方法培养食管鳞癌细胞KYSE-150和EC9706;Transwell法检测TSA、蛋白激酶C(PKC)抑制剂AEB071对食管鳞癌细胞迁移的影响;观察TSA、PKC抑制剂AEB071对人食管鳞癌细胞形态学的影响;Western blotting检测E-钙黏蛋白(E-cadherin)、波形蛋白(vimentin)、β-连环蛋白(β-catenin)、Slug、ac H3和H3蛋白的表达水平。结果TSA促进食管鳞癌细胞的迁移,PKC抑制剂AEB071部分抑制TSA促进食管鳞癌细胞的迁移作用;TSA促使细胞由类椭圆形的上皮样细胞形态向类似梭形的成纤维细胞样形态的上皮-间质转化(EMT),AEB071抑制TSA诱导的细胞形态学变化;TSA处理后E-cadherin蛋白表达水平降低,vimentin、β-catenin、Slug、ac H3表达水平升高,联合应用TSA与AEB071,TSA诱导的上述EMT相关蛋白水平的变化得到部分抑制,使E-cadherin蛋白表达水平增加,vimentin、β-catenin、Slug表达水平降低。结论TSA通过促进食管鳞癌细胞EMT增加其迁移能力,其机制可能由PKC相关信号通路介导。     

不同浓度曲古抑菌素A对鸡胚翅芽发育的影响

目的 观察组蛋白去乙酰化酶(HDAC)抑制剂曲古抑菌素A(TSA)对鸡胚翅芽发育中某些基因表达水平的作用,探讨不同浓度TSA(75μmol/L、750 μmol/L、1.5mmol/L)对鸡胚翅芽发育的影响,提高我们对染色质结构重组和表观遗传对基因表达的调控作用,以及对正在开发的抗癌药物的认识. 方法以鸡胚翅芽作为实验模型,用TSA处理翅芽,对鸡胚胎实施原位杂交,检测与肌肉发育相关基因的表达,并采用硫酸耐尔蓝(Nile bluesulfate)法检测细胞凋亡状况. 结果 75 μmol/L TSA能够抑制与肌肉发生相关的基因MyoD和Myf5在鸡胚翅芽的表达,经TSA(75μmol/L)处理的胚胎没有发生明显的细胞凋亡.但是随着TSA药物浓度的提高,TSA(≥750μmol/L)不仅强烈抑制相关基因的表达,而且出现翅芽外部畸形(外形改变、体积缩小)以及细胞凋亡. 结论75μmol/LTSA调控某些重要的转录因子及有力地控制肌肉细胞的分化;高浓度TSA(≥750μmol/L)导致细胞凋亡和胚胎翅芽畸形;发育的鸡胚能够作为一个便利的,供体内研究药物(如HDAC抑制剂类等)的模型.     

曲古抑菌素A对心衰大鼠心脏促炎细胞因子及心功能的影响

目的: 观察组蛋白脱乙酰化酶抑制剂曲古抑菌素A(TSA)对心肌梗死后心衰(HF)大鼠心脏肿瘤坏死因子(TNF-α)、白细胞介素-1β(IL-1β)和诱导型一氧化氮合酶(iNOS)及心功能的影响。方法: 采用冠状动脉左前降支结扎术致心肌梗死制备大鼠HF模型和假手术模型(sham),给予TSA或vehicle处理。给药4周后,测定血流动力学参数,应用免疫组织化学和ELISA检测左室心肌TNF-α、IL-1β和iNOS的水平,并测定右室/体重(RV/BW)、肺重/体重(LW/BW)。结果: 与HF+vehide组相比,给予TSA后可使HF大鼠心肌组织内增高的TNF-α、IL-1β和iNOS含量明显降低(P<0.05),左室舒张末压(LVEDP)和LW/BW降低(P<0.05);降低的左室内压最大上升速率(+dp/dt_max)和左室内压最大下降速率(-dp/dt_max)明显升高(P<0.05)。结论: 组蛋白脱乙酰化酶抑制剂TSA抑制心肌梗死后HF大鼠心肌组织TNF-α、IL-1β及iNOS的产生,并且可能通过该抑制作用改善HF大鼠的心功能,减轻肺淤血。     

曲古抑菌素A通过JNK/MAPK信号通路介导乳腺癌MDA-MB-231细胞的凋亡

目的　探讨TSA对乳腺癌MDA-MB-231细胞增殖、凋亡的影响及作用机制。 方法　采用MTT、克隆形成、流式细胞术检测TSA对乳腺癌MDA-MB-231细胞生物学功能的影响;Western Blot 和qRT-PCR 检测细胞增殖、凋亡和MAPK信号通路蛋白及mRNA 的表达水平的影响;抑制JNK通路检测可能的作用机制。 结果　TSA呈剂量依赖性抑制细胞增殖和诱导凋亡,使细胞阻滞于G1期;TSA可上调P21、Caspase-3、Bax、p-JNK蛋白及mRNA表达,下调Cyclin D1、Cdk4、Bcl-2蛋白及mRNA表达;抑制JNK通路后,p-JNK蛋白和细胞总凋亡率降低,Caspase-3、Bax蛋白及mRNA表达减少,Bcl-2蛋白及mRNA表达增多。 结论　TSA通过MAPK信号通路介导JNK的磷酸化,调控乳腺癌MDA-MB-231细胞的凋亡。     

曲古抑菌素A促进小鼠骨髓间充质干细胞分化为胰岛素分泌细胞

 目的： 观察曲古抑菌素A(TSA)诱导小鼠骨髓间充质干细胞分化为胰岛素分泌细胞的适宜浓度。方法: C57BL/6小鼠骨髓间充质干细胞系体外培养。实验分为5组：对照组（DMSO,A组)和TSA干预组（25 nmol/L,B组;50 nmol/L,C组;100 nmol/L,D组;200 nmol/L,E组）。各组分两阶段用相应的培养基培养10 d后进行检测。双硫腙染色鉴定各组的胰岛素分泌细胞,结果进行半定量分析。免疫荧光染色鉴定各组的胰岛素分泌,比较各组胰岛素平均荧光强度。酶联免疫吸附试验检测各组胰岛素分泌细胞胰岛素的分泌量。结果: TSA作用10 d能够诱导C57BL/6 小鼠骨髓间充质干细胞分化成为胰岛素分泌细胞并分泌胰岛素。 B组胰岛素染色阳性面积、阳性率、胰岛素染色积分吸光度以及胰岛素平均荧光强度显著高于其它干预组,差异有统计学意义（均P<0.05）。 随着各干预组TSA浓度的升高,胰岛素的分泌量减少。B组胰岛素含量显著高于其它干预组,差异有统计学意义（均P<0.05）。结论：TSA处理10 d能诱导C57BL/6 小鼠骨髓间充质干细胞分化成为胰岛素分泌细胞,并且25 nmol/L为TSA的适宜浓度。     

组蛋白乙酰化对细胞分化的调控及其机制

近来大量实验提示体内组蛋白乙酰化状态的改变会影响到细胞的分化.目前研究主要集中在组蛋白乙酰化状态对肿瘤细胞分化、干细胞分化和胚胎发育等的影响.但其相关作用机制仍不十分清楚.本文就组蛋白乙酰化过程对细胞分化的调控以及其调控的机制进行讨论.     

5-氮-2-脱氧胞苷与曲古抑菌素A对胃癌细胞生长抑制作用的研究

目的 探讨5-氮-2-脱氧胞苷与曲古抑菌素A对胃癌细胞生长抑制作用.方法 应用MTT比色法检测各组细胞增殖情况.应用金氏公式计算联合用药效果.结果 单独及联合应用不同浓度的5-氮-2-脱氧胞苷与曲古抑菌素A作用MGC-803细胞不同时间,细胞生长抑制作用均随着药物浓度的增加和时间的延长逐渐增加,联合用药效果表现为相加作用(q>0.85).结论 单独应用5-氮-2-脱氧胞苷与曲古抑菌素A,细胞生长抑制率均明显增加;联合用药发挥相加作用,为临床联合用药提供了理论依据.     

Immunohistochemical Analysis of Histone H3 Modifications in Germ Cells during Mouse Spermatogenesis

Histone modification has been implicated in the regulation of mammalian spermatogenesis. However, the association of differently modified histone H3 with a specific stage of germ cells during spermatogenesis is not fully understood. In this study, we examined the localization of variously modified histone H3 in paraffin-embedded sections of adult mouse testis immunohistochemically, focusing on acetylation at lysine 9 (H3K9ac), lysine 18 (H3K18ac), and lysine 23 (H3K23ac); tri-methylation at lysine 4 (H3K4me3) and lysine 27 (H3K27me3); and phosphorylation at serine 10 (H3S10phos). As a result, we found that there was a significant fluctuation in the modifications; in spermatogonia, the stainings for H3K9ac, H3K18ac, and H3K23ac were strong while that for H3K4me3 was weak. In spermatocytes, the stainings for H3K9ac, H3K18ac, H3K23ac, and H3K4me3 were reduced in the preleptotene to pachytene stage, but in diplotene stage the stainings for H3K18ac, H3K23ac, and H3K4me3 seemed to become intense again. The staining for H3K27me3 was nearly constant throughout these stages. In the ensuing spermiogenesis, a dramatic acetylation and methylation of histone H3 was found in the early elongated spermatids and then almost all signals disappeared in the late elongated spermatids, in parallel with the replacement from histones to protamines. In addition, we confirmed that the staining of histone H3S10phos was exclusively associated with mitotic and meiotic cell division. Based upon the above results, we indicated that the modification pattern of histone H3 is subject to dynamic change and specific to a certain stage of germ cell differentiation during mouse spermatogenesis.     

Trichostatin A (TSA) improves the development of rabbit-rabbit intraspecies cloned embryos, but not rabbit-human interspecies cloned embryos.

The interspecies somatic cell nuclear transfer (iSCNT) technique for therapeutic cloning gives great promise for treatment of many human diseases. However, the incomplete nuclear reprogramming and the low blastocyst rate of iSCNT are still big problems. Herein, we observed the effect of TSA on the development of rabbit-rabbit intraspecies and rabbit-human interspecies cloned embryos. After treatment with TSA for 6 hr during activation, we found that the blastocyst rate of rabbit-rabbit cloned embryos was more than two times higher than that of untreated embryos; however, the blastocyst rate of TSA-treated rabbit-human interspecies cloned embryos decreased. We also found evident time-dependent histone deacetylation-reacetylation changes in rabbit-rabbit cloned embryos, but not in rabbit-human cloned embryos from fusion to 6 hr after activation. Our results suggest that TSA-treatment does not improve blastocyst development of rabbit-human iSCNT embryos and that abnormal histone deacetylation-reacetylation changes in iSCNT embryos may account for their poor blastocyst development.     

Histone H3 phosphorylation of mammalian chromosomes

Inferences about the role and location of phosphorylated histone H3 are derived primarily from biochemical studies. A few direct observations at chromosome level have shown that phosphorylation begins at the site of heterochromatin and spreads throughout the chromosome. However, a comparative study of chromosomes of mouse (L929 cells), Chinese hamster (CHO 9 cells) and the Indian muntjac (male cells) reveals some distinguishable details among mammalian species. Whereas the L929 cells exhibit the typical pattern of phosphorylation at the region of centromeric heterochromatin associated with the active centromere, the heterochromatin blocks associated with the inactive centromeres also show label of about equivalent intensity. Throughout the cell cycle, heterochromatin exhibits sharper (denser) and better defined label than does euchromatin which expresses somewhat diffuse label. The centromere constriction on biarmed chromosomes, originating in Robertsonian translocations, appears phosphorylated in some, if not all chromosomes. A similar situation was found for the CHO 9 cells indicating that phosphorylation does include the region in which H3 is supposedly replaced by CENP-A. An interesting feature of the CHO cell line was the dense label at and near the telomeres; this feature was not observed in either the mouse or the Indian muntjac. The centromere regions of the Indian muntjac chromosomes showed three sites of label in the multicentric X chromosome and two each on chromosome pair number 1 and Y₂; the sites coinciding with the reaction sites of antikinetochore antibodies. Also, the X and Y₁ chromosomes of Indian muntjac show intense phosphorylation at the sites of secondary constrictions.The chromosomes of all three species were phosphorylated throughout the cell cycle. As the chromosomes started to decondense during anaphase, heavy phosphorylation was observed in the form of discontinuous beaded structures indicating partial despiralization of the chromosome. Interestingly, when cells had completed karyokinesis and resolved into two independent nuclei, the phosphorylation was observed at the midbody. At this stage, the cytoplasm appeared to be again phosphorylated.     

Histone H3.3 maintains genome integrity during mammalian development

Histone H3.3 is a highly conserved histone H3 replacement variant in metazoans and has been implicated in many important biological processes, including cell differentiation and reprogramming. Germline and somatic mutations in H3.3 genomic incorporation pathway components or in H3.3 encoding genes have been associated with human congenital diseases and cancers, respectively. However, the role of H3.3 in mammalian development remains unclear. To address this question, we generated H3.3-null mouse models through classical genetic approaches. We found that H3.3 plays an essential role in mouse development. Complete depletion of H3.3 leads to developmental retardation and early embryonic lethality. At the cellular level, H3.3 loss triggers cell cycle suppression and cell death. Surprisingly, H3.3 depletion does not dramatically disrupt gene regulation in the developing embryo. Instead, H3.3 depletion causes dysfunction of heterochromatin structures at telomeres, centromeres, and pericentromeric regions of chromosomes, leading to mitotic defects. The resulting karyotypical abnormalities and DNA damage lead to p53 pathway activation. In summary, our results reveal that an important function of H3.3 is to support chromosomal heterochromatic structures, thus maintaining genome integrity during mammalian development.     

Histone deacetylase inhibition enhances adenoviral vector transduction in inner ear tissue

Adenovirus vectors (AdVs) are efficient tools for gene therapy in many tissues. Several studies have demonstrated successful transgene transduction with AdVs in the inner ear of rodents [Kawamoto K, Ishimoto SI, Minoda R, Brough DE, Raphael Y (2003) J Neurosci 23:4395–4400]. However, toxicity of AdVs [Morral N, O'Neal WK, Rice K, Leland MM, Piedra PA, Aguilar-Cordova E, Carey KD, Beaudet AL, Langston C (2002) Hum Gene Ther 13:143–154.] or lack of tropism to important cell types such as hair cells [Shou J, Zheng JL, Gao WQ (2003) Mol Cell Neurosci 23:169–179] appears to limit their experimental and potential clinical utility. Histone deacetylase inhibitors (HDIs) are known to enhance AdV-mediated transgene expression in various organs [Dion LD, Goldsmith KT, Tang DC, Engler JA, Yoshida M, Garver RI Jr (1997) Virology 231:201–209], but their effects in the inner ear have not been documented. We investigated the ability of one HDI, trichostatin A (TSA), to enhance AdV-mediated transgene expression in inner ear tissue. We cultured neonatal rat macular and cochlear explants, and transduced them with an AdV encoding green fluorescent protein (Ad-GFP) under the control of a constitutive promoter for 24 h. In the absence of TSA, GFP expression was limited, and very few hair cells were transduced. TSA did not enhance transduction when applied at the onset of Ad-GFP transduction. However, administration of TSA during or just after Ad-GFP application increased GFP expression in supporting cells approximately fourfold. Moreover, vestibular hair cell transduction was enhanced approximately sixfold, and that of inner hair cells by more than 17-fold. These results suggest that TSA increases AdV-mediated transgene expression in the inner ear, including the successful transduction of hair cells. HDIs, some of which are currently under clinical trials (Sandor et al., 2002), could be useful tools in overcoming current limitations of gene therapy in the inner ear using Ad-GFP.     

Trichostatin A attenuates airway inflammation in mouse asthma model

BACKGROUND: Histone deacetylase (HDAC) inhibition has been demonstrated to change the expression of a restricted set of cellular genes. T cells are essential in the pathogenesis of allergen-induced airway inflammation. It was recently reported that treatment with HDAC inhibitors induces a T cell-suppressive effect. OBJECTIVE: The purpose of this study was to determine whether treatment with trichostatin A (TSA), a representative HDAC inhibitor, would reduce allergen-induced airway inflammation in a mouse asthma model. METHODS: BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA) and challenged with an aerosol of OVA. TSA (1 mg/kg body weight) was injected intraperitoneally every 2 days beginning on day 1. Mouse lungs were assayed immunohistochemically for HDAC1, a major HDAC subtype, and for infiltration of CD4+ cells. The effect of TSA on airway hyper-responsiveness (AHR) was determined, and the bronchoalveolar lavage fluid (BALF) of these mice was assayed for the number and types of inflammatory cells, and for the concentrations of IL-4, IL-5, and IgE. RESULTS: HDAC1 was localized within most airway cells and infiltrating inflammatory cells of asthmatic lungs. Treatment with TSA significantly attenuated AHR, as well as the numbers of eosinophils and lymphocytes in BALF. TSA also reduced infiltration of CD4+ and inflammatory cells and mucus occlusions in lung tissue, and decreased the concentrations of IL-4, IL-5, and IgE in BALF. CONCLUSION: TSA attenuated the development of allergic airway inflammation by decreasing expression of the Th2 cytokines, IL-4 and IL-5, and IgE, which resulted from reduced T cell infiltration. Our results suggest that HDAC inhibition may attenuate the development of asthma by a T cell suppressive effect.     

Histone deacetylase 1, 2, 6 and acetylated histone H4 in B- and T-cell lymphomas

Aims:  Histone deacetylase (HDAC) inhibitors are novel therapeutics in the treatment of peripheral T-cell lymphoma, unspecified (PTCL) and diffuse large B-cell lymphoma (DLBCL), where, for unknown reasons, T-cell malignancies appear to be more sensitive than B-cell malignancies. The aim was to determine HDAC expression in DLBCL and PTCL which has not previously been investigated.
Methods and results:  The expression of HDAC1, HDAC2, HDAC6 and acetylated histone H4 was examined immunohistochemically in 31 DLBCL and 45 PTCL. All four markers showed high expression in both DLBCL and PTCL compared with normal lymphoid tissue. HDAC1 was more abundantly expressed in PTCL than in DLBCL ( P  = 0.0046), whereas acetylated H4 was more frequent in DLBCL ( P  < 0.0001), the latter suggesting a mechanism for T-cell lymphoma sensitivity to HDAC inhibitors. Moderate to strong HDAC6 expression was significantly correlated with favourable outcome ( P  = 0.016) in DLBCL patients, whereas the opposite effect was observed in PTCL patients ( P  < 0.0001). The other markers did not correlate with survival ( P  > 0.05).
Conclusions:  HDAC1, HDAC2, HDAC6 and acetylated H4 are overexpressed in DLBCL and PTCL relative to normal lymphoid tissue. Furthermore, HDAC6 may be an important prognostic marker associated with favourable outcome in DLBCL and a more aggressive course in PTCL.