组蛋白去乙酰化酶抑制剂的研究进展

组蛋白乙酰化和去乙酰化可调节染色体的多种功能,如基因表达和染色体分离等。研究发现,组蛋白去乙酰化酶抑制剂(histone deacetylase inhibitors, HDACIs)可诱导肿瘤细胞及干细胞分化、生长阻断和凋亡。现综述HDAC抑制剂的种类、生物学作用、抗肿瘤作用机制的研究进展及应用前景等。     

组蛋白去乙酰化酶抑制剂治疗多聚谷氨酰胺病的研究进展

近年研究发现基因转录异常可导致亨廷顿病(Huntington's disease,HD)等多聚谷氨酰胺(polyglutamine,PolyQ)病中的神经元功能异常.组蛋白去乙酰化酶(histone deacetylases,HDACs)作为一种转录抑制因子,可与辅阻遏物复合体相互作用导致染色质重塑,最终抑制目的基因的转录.PolyQ蛋白与基因转录调控因子异常的相互作用可能是PolyQ病转录失调的原因之一.作者就PolyQ病转录失调的可能发生机制,尤其是组蛋白乙酰转移酶(histone acetyltransferases,HATs)和HDACs在其中所起的作用,以及组蛋白去乙酰化酶抑制剂(histone deacetylases inhibitors,HDACIs)的治疗潜能等方面予以综述.     

Ⅱ类组蛋白去乙酰化酶与临床

Ⅱ类组蛋白去乙酰化酶(HDACs)及其相互作用分子在与临床相关的生物学过程中发挥着重要作用.近年来发现,Ⅱ类组蛋白去乙酰化酶与临床心血管疾病、呼吸系统疾病和骨软骨疾病的发生、肿瘤进展以及药学研究等密切相关.本文就Ⅱ类HDACs与临床的关系进行了综述.     

RNA干扰组蛋白去乙酰化酶4诱导骨肉瘤细胞凋亡

目的探讨沉默组蛋白去乙酰化酶4(HDAC4)对骨肉瘤细胞HOS,U2OS生物学行为的影响。方法用脂质体瞬时转染法将化学合成HDAC4-siRNA转染至骨肉瘤HOS及U2OS细胞中,实时荧光定量PCR(q-PCR)法检测细胞中HDAC4 mRNA的表达;蛋白质免疫印迹法(Western blot)检测细胞HDAC4及其下游基因HIF-1α的蛋白表达;CCK-8法检测细胞的增殖能力;流式细胞仪检测细胞凋亡;Transwell小室法检测细胞的侵袭能力。结果转染后HOS及U2OS细胞中HDAC4 mRNA表达明显降低(P0.01)。沉默HDAC4后HOS细胞早期凋亡率为(16.8±2.1)%,较si-control组(10.2±2.5)%明显增加(P0.05);U2OS细胞早期凋亡率为(21.4±3.1)%,较si-control组(12.5±2.3)%明显增加(P0.05);HOS细胞si-con组及si-HDAC4组细胞的穿膜细胞数分别为(146±34)个、(45±20)个,U2OS细胞为(207±35)个、(121±23)个,分别显著低于si-con组(P0.05)。si-HDAC4能够明显降低HDAC4以及下游基因HIF-1α的表达。结论针对HDAC4基因的特异性RNA小干扰片段能够下调HDAC4mRNA及蛋白的表达,并抑制骨肉瘤细胞的增殖和侵袭,诱导细胞凋亡。     

组蛋白去乙酰化酶抑制剂与细胞周期和凋亡关系的研究进展

表观遗传学是目前遗传学研究的热点。组蛋白乙酰化修饰是一种重要的表观遗传学调控方式,参与调控染色质构象变化和转录表达过程,组蛋白乙酰化状态紊乱与肿瘤的发生发展关系密切。研究发现,组蛋白去乙酰化酶抑制剂(histone deacetylase in-hibitor,HDACi)可以纠正肿瘤细胞异常的乙酰化状态,诱导肿瘤细胞发生细胞周期停滞和凋亡,逆转肿瘤细胞恶性表型。1组蛋白乙酰化酶(histone acetyltransferase,HAT)和组蛋白去乙酰化酶(histone deacetylase,HDAC)真核生物染色体的基本单位是核小体,核小体的核心是由4种组蛋白(H2A、H2B、H3和H4)各2…     

组蛋白去乙酰化酶抑制剂SAHA诱导骨髓瘤细胞的凋亡

背景：SAHA是一种新型的组蛋白去乙酰化酶抑制剂,目前有关其对多发性骨髓瘤细胞作用的研究还少见报道,而且其诱导细胞凋亡的分子机制还不十分清楚。 目的：观察SAHA对多发性骨髓瘤细胞株U266细胞增殖和凋亡的影响,并分析其可能机制。 方法：采用锥虫蓝拒染法、四氮唑蓝比色法检测SAHA 对U266细胞增殖的影响。AllllexinV和PI染色后应用流式细胞仪检测SAHA 作用U266细胞的凋亡率,Hoechst33342染色法检测凋亡细胞的形态。Western-blot方法检测信号转导通路Ras/Raf/Mek/Erk相关蛋白的表达水平。 结果与结论：锥虫蓝拒染法和四氮唑蓝比色法均显示,SAHA可明显抑制U266细胞增殖,且具有时间剂量依赖性。0.5,2,4 μmol/L SAHA作用U266细胞48 h后,经流式细胞仪检测细胞凋亡率分别为 (17.61±1.30)%,(43.13±3.80)%和(74.01±4.39)%,呈剂量依赖性(P < 0.05)。Hoechst33342染色荧光显微镜下可见,SAHA组细胞胞核出现明显的核固缩、核碎裂,而对照组改变不明显。Western-blot结果显示U266细胞经SAHA处理后,Raf-1和Erk蛋白的磷酸化水平受到明显抑制,药物作用48 h时出现显著降低。提示SAHA抑制多发性骨髓瘤细胞株U266细胞增殖并诱导凋亡,信号转导通路Ras/Raf/Mek/Erk阻断是机制之一。     

组蛋白去乙酰化酶抑制剂有效对抗卵巢癌细胞

他们发现并表达了一种突变的无功能p53蛋白的9种卵巢癌细胞系对组蛋白去乙酰化酶抑制剂(HDACIs)的生长抑制作用敏感。HDACIs，包括丙戊酸和SAHA，有效地抑制了人类卵巢癌细胞的增生，并诱发了凋亡。     

组蛋白去乙酰化酶抑制剂SAHA对小鼠淋巴细胞增殖和凋亡的影响

研究辛二酰苯胺异羟肟酸(SAHA)对小鼠淋巴细胞活化、增殖和凋亡的影响,并对其免疫调控机制进行初步探讨。以MTS检测淋巴细胞的增殖情况;以双色荧光抗体染色技术结合流式细胞术检测SAHA对T淋巴细胞早期活化抗原CD69表达的影响;采用碘化丙锭(PI)染色检测SAHA对淋巴细胞周期的影响;以Annexin V-PE染色分析细胞凋亡;应用免疫印迹检测SAHA对Cleaved caspase-3表达的影响。结果显示,SAHA对Con A刺激的淋巴细胞增殖具有抑制作用,其IC50为0.30±0.06μmol/L;SAHA对淋巴细胞的早期活化抗原CD69的表达具有明显的抑制作用(P<0.05);PI染色、Annexin V-PE染色和免疫印迹结果均显示,SAHA对小鼠淋巴细胞的凋亡具有促进作用,且呈剂量依赖性。研究表明,SAHA可能通过抑制小鼠淋巴细胞的活化、增殖以及促进其凋亡而发挥免疫调控功能。     

组蛋白去乙酰化酶11与基因表达

组蛋白去乙酰化酶11(histone deacetylases11,HDAC11)是最新发现的第Ⅳ类HDACs成员,是调节APC细胞IL-10转录的关键因子,对移植免疫耐受的产生起着负性作用.HDAC11还与中枢神经系统的发育有着紧密联系.拟通过对HDAC11在染色质中的作用靶点和作用机制进行综述,以期为移植免疫耐受的诱导和神经系统的功能的调节寻找到适宜的靶点.     

组蛋白去乙酰化酶调控软骨细胞终末分化的机制

终末分化是软骨细胞获得分化的默认途径,包括肥大与凋亡两种方式。无论是在骨组织生理条件下的软骨生长板形成及内源性成骨骨化,还是骨关节炎病理情况时的软骨表型改变,皆存在有相关分化过程的发生。组蛋白去乙酰化酶对于软骨细胞的生长、维持和增殖方面具有重要意义。它可通过调节基因表达和激活相关转录因子的方式介导某些疾病的发展,但目前其具体的分子生物学和生物力学机制仍不明确。本文将从生物物理学角度对组蛋白去乙酰化酶在软骨组织终末分化过程中的参与机制以及对于软骨组织工程应用价值进行总结和讨论。     

Class I and II histone deacetylase inhibition by ITF2357 reduces SLE pathogenesis in vivo

We sought to determine if a specific class I and II HDAC inhibitor (ITF2357) was able to decrease disease in lupus-prone NZB/W mice through regulation of T cell profiles. From 22 to 38 weeks-of-age, NZB/W and non-lupus NZW mice were treated with ITF2357 (5 mg/kg or 10 mg/kg), or vehicle control. Body weight and proteinuria were measured every 2 weeks, while sera anti-dsDNA and cytokine levels were measured every 4 weeks. Kidney disease was determined by sera IgG levels, immune complex deposition, and renal pathology. T lymphocyte profiles were assessed using flow cytometric analyses. Our results showed that NZB/W mice treated with the 10mg/kgof ITF2357 had decreased renal disease and inflammatory cytokines in the sera. Treatment with ITF2357 decreased the Th17 phenotype while increasing the percentage of Tregs as well as Foxp3 acetylation. These results suggest that specific HDAC inhibition may decrease disease by altering T cell differentiation and acetylation.     

T cell tolerance induced by histone deacetylase inhibitor is mediated by P21cip1

MEB [n-butyrate 2-(4-morpholinyl) ethyl butyrate hydrochloride], a histone deacetylase inhibitor and G1 blocker, has been shown to induce unresponsiveness in antigen-activated Th1 cells. MEB was tested for here for its ability to inactivate naive alloantigen-specific T cells from DBA/2 and C57BL/10 mice. Since T cells from these two strains of mice have been shown to differ in their cell cycle regulation, it we hoped that this comparison would provide information concerning the role of cycle regulatory proteins in mediating MEB-induced T cell unresponsiveness. MEB inhibited proliferation in a one-way mixed lymphocyte reaction (MLR) in which spleen cells from DBA/2 mice (H-2^d) or C57BL/10 mice (H-2^b) were stimulated with spleen cells from C57BL/10 or DBA/2 mice, respectively. C57BL/10 responder T cells isolated from the MEB-treated primary MLR remained unresponsive to alloantigen following restimulation in a secondary MLR that did not contain MEB. T cells from DBA/2 mice were less sensitive to MEB-induced unresponsiveness and required a longer exposure or pretreatment with IL-2 to become tolerant. In all cases responsiveness to MEB-induced tolerance in the alloantigen-stimulated T cells corresponded with the levels of the cyclin-dependent kinase inhibitor p21^cip1. Additional experiments showed that T cells from p21^cip1-deficient mice, unlike T cells from p21^cip1 wild-type littermates, were resistant to MEB-induced tolerance. These results underscore the role of p21^cip1 in mediating T cell tolerance induced by the histone deacetylase inhibitor MEB.     

The effects of sodium butyrate,an inhibitor of histone deacetylase,on the cocaine- and sucrose-maintained self-administration in rats

In order to substantiate the concept that cocaine behavioral effects may be influenced by histone modification, rats were trained to self-administer cocaine intravenously (0.75 mg/(kg injection)), and were systemically pretreated with sodium butyrate (NaBu), a potent histone deacetylase inhibitor, before the test session during the maintenance phase. The effect of NaBu on a control reinforcer (sucrose)-induced self-administration was also assessed. NaBu (100–200 mg/kg) was inactive in altering the cocaine (0.75 mg/(kg injection))-maintained responding and at the highest dose (400 mg/kg) it did increase cocaine-induced lever presses during the maintenance phase. On the other hand, sucrose-reinforcing potential was not altered when NaBu was given at the highest dose (400 mg/kg). These findings extend previous observations that changes in histone acetylation are relevant to cocaine-induced behavioral effects. Given that histone acetylase inhibitor enhances cocaine-induced behavioral plasticity, the therapeutic benefits of histone acetyltransferase inhibitors warrant further investigation in the experimental models of cocaine abuse.     

HDAC抑制剂丙戊酸对小鼠T淋巴细胞表达细胞因子的影响

目的分析组蛋白去乙酰化酶(HDAC)抑制剂丙戊酸(Valproic acid,VPA)对小鼠T细胞亚群IL-2、IFN-γ和IL-6表达的影响,探讨其抗炎免疫调节作用的机制。方法经VPA处理小鼠淋巴细胞,并在佛波醇酯(PDB)和离子霉素刺激后,以流式细胞术分析CD3+、CD4+和CD8+T细胞表达IL-2、IFN-γ和IL-6的情况。结果淋巴细胞受刺激后,IL-6的表达水平仅稍有提高,而IL-2在CD4+和CD8+T细胞表达率分别为35.49%和5.50%,IFN-γ表达率分别为3.47%和38.60%。经VPA处理后,CD3+T细胞IL-6+、IFN-γ+和IL-6+IFN-γ+的表达均受剂量依赖性抑制(P<0.01)。同样,VPA能够剂量依赖性地降低小鼠CD4+和CD8+T细胞亚群内表达IL-2+、IFN-γ+的细胞比例(P<0.01),对于IL-2+IFN-γ+双阳性细胞的比例也具有明显抑制作用(P<0.01);此外,VPA对CD8+T细胞表达IFN-γ的抑制程度高于CD4+T细胞。结论 HDAC抑制剂VPA通过抑制IL-2和IFN-γ而发挥其抗炎和免疫调节效应。     

组蛋白去乙酰化酶1在子宫内膜异位症中的表达及意义

目的 研究组蛋白去乙酰化酶1(HDAC1)在子宫内膜异位症患者在位及异位内膜中的表达,探讨其在子宫内膜异位症发生、发展中的作用. 方法 应用免疫组织化学和免疫印迹法检测20例子宫内膜异位症患者在位内膜和异位内膜组织(研究组)中及20例子宫肌瘤患者的子宫内膜组织(对照组)HDAC1的表达情况. 结果 HDAC1阳性着色主要分布于子宫内膜上皮细胞和间质细胞的细胞核,在位内膜中HDAC1的表达强度明显高于对照组子宫内膜(P<0.01).免疫印迹检测提示,子宫内膜异位症在位内膜和异位内膜组织中HDAC1蛋白的相对表达量分别为2.67±0.69和2.55±1.36,显著高于对照组子宫内膜1.63±0.93(P<0.01,P<0.05);而在位内膜组与异位内膜组之间无统计学差异(P＞0.05). 结论 HDAC1在子宫内膜异位症在位和异位内膜组织中的高表达,可能在子宫内膜异位症的发生、发展中起重要作用.     

组蛋白去乙酰化酶抑制剂促大鼠胚胎干细胞向神经元分化

目的探讨组蛋白去乙酰化酶（HDAC）抑制剂丁酸钠（NaB）对大鼠胚胎干细胞（ESC）向神经元分化的影响。方法利用含bFGF、EGF的DMEM／F12培养基培养原代ESC;应用DAPI染色,荧光显微镜观察不同药物浓度NaB（0．2、1、2μmol／L）作用48h后对细胞凋亡的影响;免疫荧光检测NaB（1μmol／L）作用72h后和对照组（PBS）ESC双肾上皮质激素（DCX）和DAPI,计算DCX／DAPI的比值;免疫印迹检测不同浓度NaB（0．2、1、2μmol／L）作用48h后和对照组（PBS）ESC组蛋白H3、H4乙酰化水平。结果在1、2／μmol／LNaB组ESC出现明显凋亡,细胞形状不规则,核固缩,核内可见致密的颗粒荧光,视野下细胞碎片较多,且凋亡细胞百分比明显高于0．2μmol／LNaB组和对照组[（7．85±0．73）％、（18．42±2．04）％比（3．48±0．35）％、（2．16±0．32）％,均P〈0．05]。1μmol／LNaB组ESCDCX／DAPI比值高于对照组（38．51±4．33比14．81±1．77,P〈0．05）。随NaB药物浓度的增加,ESC蛋白H3、H4乙酰化程度较对照组增强,0．2±mol／L组处理后乙酰化组蛋白H3和H4表达变化不明显,1、2μmol／L时组蛋白H3和H4乙酰化程度明显增高（均P〈0．05）。结论HDAC抑制剂NaB可明显促使ESC向神经元分化。     

Effect of histone deacetylase inhibitors on the cell nucleus and nucleolus of leukemic myeloblasts in vitro - a cytochemical study

The present study was designed to provide complementary information on the effects of histone deacetylase inhibitors (HDACi's) such as trichostatin A (TSA) and sodium valproate (VAP) on nuclei and nucleoli of leukemic myeloblasts represented by cultured Kasumi-1 cells. The number of apoptotic cells and bodies with characteristic chromatin condensation and fragmentation was greater after TSA treatment. However, in contrast to TSA, myeloblasts treated with VPA recovered and started to proliferate again. TSA-treated myeloblasts with a fine chromatin structure exhibited an intense phagocytosis of cell fragments. The decreased number and translocation of silver-stained proteins of nucleolus organiser regions (AgNORs) in large nucleoli of myeloblasts treated with HDACi's indicated that these cells entered apoptosis and/or ageing without preceding terminal maturation. The nucleolar asynchrony observed in an increased number of treated cells with both HDACi's studied here possibly represented myeloblasts resistant to such treatment. In conclusion, this study demonstrates that the chromatin structure and nucleoli visualised by simple cytochemical procedures provides useful information on the effects of HDACi's on myeloblasts and facilitated detection of these effects at the single cell level.     

Tregs调节小鼠肝癌局部引流淋巴结内免疫效应细胞的功能

目的:探讨肿瘤引流淋巴结(TDLNs)内调节性T细胞(Tregs)对局部免疫效应细胞的调节作用。方法:建立小鼠肝癌TDLNs模型,通过免疫组织化学染色和流式细胞仪检测TDLNs内Foxp3+Tregs和CD4+及CD8+T细胞的数量。实时定量PCR测定Foxp3mRNA表达水平。应用酶联免疫斑点法(ELISPOT)检测TDLNs内CD8+T细胞分泌IFN-γ的功能。结果:TDLNs内Tregs和效应性T细胞均明显扩增,Tregs弥散分布于CD8+T细胞聚居区。TDLNs内Foxp3mRNA表达水平显著高于同一接种肿瘤小鼠腹股沟淋巴结(P0.01)和脾脏(P0.01)。Tregs趋向于在TDLNs内聚集,而非其它外周淋巴结位点。荷瘤小鼠的脾脏Foxp3mRNA表达明显高于注射LPS小鼠脾脏。Tregs抑制TDLNs内已初始化的CD8+T细胞分泌IFN-γ的功能,经anti-CD3刺激激活后,CD8+T细胞分泌IFN-γ的功能可恢复。结论:TDLNs内Tregs通过调控CD8+T细胞功能而发挥重要作用,清除Tregs是发挥特异性肿瘤免疫治疗的关键。