Lysine-specific demethylase 1 inhibitor rescues the osteogenic ability of mesenchymal stem cells under osteoporotic conditions by modulating H3K4 methylation

Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.

Lysine-specific demethylase 1 expression in zebrafish during the early stages of neuronal development

Lysine-specific demethylase 1 （Lsdl） is associated with transcriptional coregulation via the modulation of histone methylation. The expression pattern and function of zebrafish Lsdl has not, however, been studied. Here, we describe the pattern of zebrafish Lsdl expression during different development stages. In the zebrafish embryo, Isdl mRNA was present during the early cleavage stage, indicating that maternally derived Lsdl protein is involved in embryonic patterning. During embryogenesis from 0 to 48 hours post-fertilization （hpf）, the expression of Isdl mRNA in the embryo was ubiquitous before 12 hpf and then became restricted to the antedor of the embryo （particularly in the brain） from 24 hpf to 72 hpf. Inhibition of Lsdl activity （by exposure to tranylcypromine） or knockdown of Isdl expression （by morpholino antisense oligonucleotide injection） led to the loss of cells in the brain and to a dramatic downregulatJon of neural genes, including gad65, gad75, and reelin, but not hey1. These findings indicate an important role of Lsdl during nervous system development in zebrafish.

Lysine-specific Demethylase 1 Represses THP-1 Monocyte-to-macrophage Differentiation

Objective To investigate the role of lysine-specific demethylase 1 (LSD1) in the process of THP-1 monocyte-to-macrophage differentiation.Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting were performed to analyze the expression of LSD1 and interleukin-6 (IL-6) in THP-1 monocytes and THP-1-derived macrophages.Chromatin immunoprecipitation (ChIP) assay was applied to detect the occupancy of LSD1 and H3K4 methylation at IL-6 promoter during THP-1 monocyte-to-macrophage differentiation.IL-6 mRNA level and H3K4 methylation at IL-6 promoter were analyzed using qRT-PCR and ChIP assay in LSD1-knockdown THP-1 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 0,4,8,12,and 24 hours.Fluorescence activated flow cytometry was performed to reveal the percentage of macrophages differentiated from THP-1 monocytes.Results The expression of LSD1 reduced during THP-1 monocyte-to-macrophage differentiation (P<0.01).LSD1 occupancy decreased and H3K4 methylation increased at IL-6 promoter during the differentiation.With knockdown of LSD1,H3K4 methylation at IL-6 promoter was found increased after TPA treatment at different times points (all P<0.05,except 24 hours).The percentage of macrophages increased significantly in the THP-1 cells with LSD1 knockdown (P<0.05).Conclusions LSD1 is repressed during the monocyte-to-macrophage differentiation of THP-1 cells.Suppression of LSD1-mediated H3K4 demethylation may be required for THP-1 monocyte-to-macrophage differentiation.

Mitochondrial pathway of the lysine demethylase 5C inhibitor CPI-455 in the Eca-109 esophageal squamous cell carcinoma cell line

BACKGROUND Esophageal cancer is a malignant tumor of the digestive tract that is difficult to diagnose early.CPI-455 has been reported to inhibit various cancers,but its role in esophageal squamous cell carcinoma(ESCC)is unknown.AIM To investigate the effects and mechanism of the lysine demethylase 5C inhibitor,CPI-455,on ESCC cells.METHODS A methyl tetrazolium assay was used to detect the inhibitory effect of CPI-455 on the proliferation of Eca-109 cells.Apoptosis,reactive oxygen species(ROS),and mitochondrial membrane potential were assessed by flow cytometry.Laser confocal scanning and transmission electron microscopy were used to observe changes in Eca-109 cell morphology.The protein expression of P53,Bax,lysinespecific demethylase 5C(KDM5C),cleaved Caspase-9,and cleaved Caspase-3 were assayed by western blotting.RESULTS Compared with the control group,CPI-455 significantly inhibited Eca-109 cell proliferation.Gemcitabine inhibited Eca-109 cell proliferation in a concentrationand time-dependent manner.CPI-455 caused extensive alteration of the mitochondria,which appeared to have become atrophied.The cell membrane was weakly stained and the cytoplasmic structures were indistinct and disorganized,with serious cavitation when viewed by transmission electron microscopy.The flow cytometry and western blot results showed that,compared with the control group,the mitochondrial membrane potential was decreased and depolarized in Eca-109 cells treated with CPI-455.CPI-455 significantly upregulated the ROS content,P53,Bax,Caspase-9,and Caspase-3 protein expression in Eca-109 cells,whereas KDM5C expression was downregulated.CONCLUSION CPI-455 inhibited Eca-109 cell proliferation via mitochondrial apoptosis by regulating the expression of related genes.

DNA N^6-methyladenine demethylase ALKBH1 enhances osteogenic differentiation of human MSCs

ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine （N6-mA）, a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells （MSCs） was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.

Histone demethylase JMJD3 downregulation protects against aberrant force-induced osteoarthritis through epigenetic control of NR4A1

Osteoarthritis(OA)is a prevalent joint disease with no effective treatment strategies.Aberrant mechanical stimuli was demonstrated to be an essential factor for OA pathogenesis.Although multiple studies have detected potential regulatory mechanisms underlying OA and have concentrated on developing novel treatment strategies,the epigenetic control of OA remains unclear.Histone demethylase JMJD3 has been reported to mediate multiple physiological and pathological processes,including cell differentiation,proliferation,autophagy,and apoptosis.However,the regulation of JMJD3 in aberrant force-related OA and its mediatory effect on disease progression are still unknown.In this work,we confirmed the upregulation of JMJD3 in aberrant forceinduced cartilage injury in vitro and in vivo.Functionally,inhibition of JMJD3 by its inhibitor,GSK-J4,or downregulation of JMJD3 by adenovirus infection of sh-JMJD3 could alleviate the aberrant force-induced chondrocyte injury.Mechanistic investigation illustrated that aberrant force induces JMJD3 expression and then demethylates H3K27me3 at the NR4A1 promoter to promote its expression.Further experiments indicated that NR4A1 can regulate chondrocyte apoptosis,cartilage degeneration,extracellular matrix degradation,and inflammatory responses.In vivo,anterior cruciate ligament transection(ACLT)was performed to construct an OA model,and the therapeutic effect of GSK-J4 was validated.More importantly,we adopted a peptide-si RNA nanoplatform to deliver si-JMJD3 into articular cartilage,and the severity of joint degeneration was remarkably mitigated.Taken together,our findings demonstrated that JMJD3 is flow-responsive and epigenetically regulates OA progression.Our work provides evidences for JMJD3 inhibition as an innovative epigenetic therapy approach for joint diseases by utilizing p5RHH-si RNA nanocomplexes.

LSD1和PIEZO1在口腔癌中的表达及其与预后转归关系研究

目的分析赖氨酸特异性去甲基化酶1(LSD1)和压电型机械敏感离子通道组件1(PIEZO1)在口腔癌中表达及与预后转归的关系。方法选取2013年1月—2018年3月联勤保障部队第九二〇医院口腔外科收治的口腔癌患者113例,采用免疫组织化学法检测术中留取口腔癌组织和癌旁组织中LSD1、PIEZO1表达;分析口腔癌组织LSD1、PIEZO1表达与临床病理特征的关系;根据口腔癌组织LSD1、PIEZO1表达情况分为LSD1阳性表达组、PIEZO1阳性表达组、LSD1阴性表达组、PIEZO1阴性表达组;采用Kaplan-Meier法绘制LSD1、PIEZO1阳性/阴性表达口腔癌患者生存曲线,Cox回归分析影响口腔癌患者预后转归的因素。结果与癌旁组织比较,口腔癌组织中LSD1、PIEZO1阳性表达率升高(χ^(2)/P=47.684/<0.001、43.929/<0.001)。LSD1、PIEZO1在分化程度低、浸润深度>5 mm、TNM分期Ⅲ期、有淋巴结转移患者中阳性表达率升高(LSD1:χ^(2)/P=5.815/0.016、6.669/0.010、8.145/0.004、10.879/0.001,PIEZO1:χ^(2)/P=6.136/0.013、5.796/0.016、6.771/0.009、8.116/0.004)。113例口腔癌患者5年总生存率为56.64%(64/113)。Kaplan-Meier生存曲线分析显示,LSD1阳性表达组、PIEZO1阳性表达组5年总生存率分别低于LSD1阴性表达组、PIEZO1阴性表达组(χ^(2)/P=12.097/0.001、9.795/0.002)。低分化、浸润深度>5 mm、TNM分期Ⅲ期、有淋巴结转移和LSD1、PIEZO1阳性表达为影响口腔癌患者预后转归的独立危险因素[OR(95%CI)=3.131(1.129~8.679)、4.011(1.426~11.283)、5.100(1.274~20.417)、8.357(1.800~38.795)、3.623(1.059~12.395)、3.454(1.191~10.019)]。结论口腔癌组织LSD1、PIEZO1高表达,与分化程度、浸润深度、TNM分期、淋巴结转移和预后转归有关,可能成为口腔癌患者预后转归评估的生物标志物。

FEN1、GTF2IP23、KDM4A在乳腺癌组织中的表达研究

目的探讨瓣状核酸内切酶-1(FEN1)、转录因子Ⅱⅰ假基因23(GTF2IP23)、赖氨酸特异性去甲基化酶4A(KDM4A)在乳腺癌组织中的表达及相关性。方法选取2020年7月至2021年8月进行手术的女性乳腺癌患者72例及同期进行手术的乳腺良性肿瘤患者70例,收集乳腺癌患者手术切除癌组织、距癌组织5 cm癌旁组织标本及乳腺良性肿瘤患者肿瘤病理组织,连续切片后做免疫组化标记、进行免疫组化染色。反转录-实时荧光定量聚合酶链反应(RT-qPCR)法检测FEN1表达,Western blot法检测GTF2IP23、KDM4A表达,分析FEN1、GTF2IP23、KDM4A在乳腺癌组织中的表达相关性及联合检测对乳腺癌患者预后的预测价值。结果与癌旁组织相比,良性肿瘤组织、乳腺癌组织中FEN1、GTF2IP23、KDM4A表达较高(P<0.05);乳腺癌组织中FEN1、GTF2IP23、KDM4A表达高于癌旁组织(P<0.05)。乳腺癌组织中FEN1、GTF2IP23、KDM4A表达与年龄、肿瘤直径、病理分期、淋巴结转移、脉管侵犯、分化情况密切相关(P<0.05)。乳腺癌组织中FEN1与GTF2IP23、KDM4A表达呈正相关(r=0.404、0.553,均P=0.001);GTF2IP23与KDM4A表达也呈正相关(r=0.582,P=0.001)。与FEN1、GTF2IP23、KDM4A单项检测相比,三项联合检测对乳腺癌患者预后预测的灵敏度提高,特异度降低;FEN1、GTF2IP23、KDM4A的曲线下面积(AUC)分别为0.691、0.659、0.708(P<0.05)。结论FEN1、GTF2IP23、KDM4A在乳腺癌组织中呈高表达,三者具有相关性,同时与乳腺癌患者病理特征密切相关,能够较好预测乳腺癌患者的预后,为临床诊断及治疗乳腺癌提供理论依据。

Demethylase-assisted site-specific detection of N^(1)-methyladenosine in RNA

The dynamic RNA modifications have been viewed as new posttranscriptional regulator in modulating gene expression as well as in a broad range of physiological processes.N^(1)-methyladenosine(m^(1)A)is one of the most prevalent modifications existing in multiple types of RNAs.In-depth investigation of the functions of m^(1)A requires the site-specific assessment of m^(1)A stoichiometry in RNA.Herein,we established a demethylase-assisted method(DA-m^(1)A)for the site-specific detection and quantification of m^(1)A in RNA.N^(1)-methyl group in m^(1)A could result in the stalling of reverse transcription at m^(1)A site,thus producing the truncated cDNA.E.coli AlkB is a demethylase that can demethylate m^(1)A to produce adenine in RNA,thus generating full-length cDNA from AlkB-treated RNA.Evaluation of the produced amounts of full-length cDNA by quantitative real-time PCR can achieve the site-specific detection and quantification of m^(1)A in RNA.With the DA-m^(1)A method,we examined and successfully confirmed the previously well-characterized m^(1)A sites in various types of RNAs with low false positive rate.In addition,we found that the level of m^(1)A was significantly decreased at the bromodomain containing 2(BRD2)mRNA position 1674 and CST telomere replication complex component 1(CTC1)mRNA position 5643 in human hepatocellular carcinoma tissues.The results suggest that these two m^(1)A sites in mRNA may be involved in liver tumorigenesis.Taken together,the DA-m^(1)A method is simple and enables the rapid,cost-effective,and site-specific detection and quantification of m^(1)A in RNA,which provides a valuable tool to decipher the functions of m^(1)A in human diseases.

Modulation of cell death pathways in cancer stem cells: Targeting histone demethylases

Cancer stem cells (CSCs) are tumor initiating cells within the tumor mass;that play a critical role in cancer pathogenesis. CSCs regulate cancer cell survival, metastatic potential, resistance to conventional radio-chemotherapy, disease relapse and poor prognosis. Recent studies have established that the drug resistant cancers and cancer cell lines possess high stem cell like traits compared to their drug sensitive counterparts. Histone demethylases are recently been linked to drug induced reversible tolerant state in cancers. Lysine histone demethylases are enzymes those demethylate lysines in histones and can act as transcriptional repressors or activators. Apart from histones other cellular proteins like E2F1, Rb, STAT3 and p53 are also regulated by methylation and demethylation cycles. In cancer cells these enzymes regulate cell survival, migration, invasion, and proliferation. This review summarizes the current progress of research on the role of histone demethylases in supporting drug tolerant cancer stem cell state and their potential as a drug target.

Lsd1对小鼠调节性T细胞发育及活化的影响

目的探讨赖氨酸特异性去甲基化酶1(lysine-specific demethylase 1,Lsd1)对调节性T细胞(regulatory T cells,Treg)发育及活化的影响。方法利用条件性敲除胸腺T细胞中Lsd1的C57BL/6小鼠(Lsd1 fl/fl Lck-Cre),取对照组及敲除组小鼠胸腺、脾和淋巴结,通过流式细胞术检测Treg的数量和比例,并统计效应Treg(activated effector Treg cell,eTreg)和静息Treg(naive-like central Treg cell,cTreg)比例(eTreg/cTreg)的变化。结果与对照组相比,敲除组小鼠胸腺指数减小,胸腺中CD4+T细胞减少,但Treg的数量和比例增加。在外周,脾和淋巴结中Treg的比例增加,eTreg/cTreg比值增加。结论条件性敲除T细胞中Lsd1促进胸腺中Treg的发育,并可能引起脾和淋巴结中Treg的活化。

抗肿瘤药物新靶点:表观遗传组蛋白赖氨酸特异性去甲基化酶1

组蛋白赖氨酸特异性去甲基化酶1(histone lysine specific demethylase 1,LSD1)是一个黄素腺嘌呤二核苷酸(FAD)依赖的氨基氧化酶,能够特异性去除组蛋白H3K4和H3K9的单、双甲基化。利用RNA干扰技术和小分子LSD1抑制剂调节LSD1的表达量和活性,能够控制肿瘤细胞的增殖、转移和侵袭。同时,由于LSD1在多种肿瘤中高表达,靶向LSD1的抗肿瘤治疗方案表现出较高的选择性和较低的毒副作用。因此,LSD1可能成为表观遗传学抗肿瘤药物的新靶点。本文对近年来LSD1的结构、功能研究及最新的LSD1抑制剂研究进展做一综述和分析。

组蛋白去甲基化酶赖氨酸特异性去甲基化酶1在急性白血病的表达及其临床意义

本研究探讨组蛋白去甲基化酶赖氨酸特异性去甲基化酶1(lysine specific demethylase 1,LSD1)在急性白血病的表达及其临床意义。采用Western blot方法半定量检测LSD1在HL-60和SHI-1白血病细胞株、不同病情(初诊、完全缓解、复发)急性白血病(acute leukemia,AL)患者及非恶性血液病对照者骨髓单个核细胞的表达水平。随访收集AL患者的临床资料,分析LSD1表达与临床预后的关系。结果表明,HL-60细胞和SHI-1细胞LSD1均呈阳性高表达,LSD1相对含量(LSD1/β-actin灰度比)分别为4.647±3.840和1.628±0.185(n=4);72例AL患者LSD1表达程度差异较大,阳性率为56.9%(41/72),LSD1相对含量平均为1.053±1.976;17例非恶性血液病对照组LSD1阳性率为0%,LSD1相对含量为0.004±0.012。LSD1阳性率在急性髓系白血病(AML)或急性淋巴细胞白血病(ALL)患者初诊组(90.4%,77.8%)与难治/复发组(100%,100%)均高于完全缓解(CR)组(4.7%,0%)(p=0.000);LSD1相对含量在AML与ALL患者初诊组之间(1.177±1.646,1.275±1.845)、难治/复发组之间(2.050±2.470,4.107±3.676)或CR组之间(0.029±0.033,0.019±0.024)差异无统计学意义(p>0.05);AL患者LSD1阳性率在初诊组(84.6%)与难治/复发组(100%)均高于CR组(3.8%),LSD1相对含量在初诊组(1.274±1.760)、难治/复发组(3.359±3.319)及CR组(0.027±0.031)均高于对照组(p<0.01),其中难治/复发组高于初诊组与CR组(p<0.01),初诊组高于CR组(p<0.01)。结论:LSD1过高表达与AL难治/复发有关,其表达水平能反映AL患者的病情,可成为对AL预后有提示作用的生物学标志。

Targeting histone lysine-specific demethylase KDM1A/LSD1 to control epithelial-mesenchymal transition program in breast cancers

Epithelial-mesenchymal transition (EMT) is a plastic and reversible process, essential for development and tissue homeostasis. Under pathological conditions, EMT causes induction of tumor growth, angiogenesis and metastasis. According to its reversible nature, the EMT program is associated with vast epigenetic changes. Targeting the epigenetic network that controls the EMT pathway in disease progression is a novel promising strategy to fight cancer metastasis. The impact of alterations in histone methylation in cancer has led to the identification of histone methyltransferases and demethylases as promising novel targets for therapy. Specifically, the lysine specific demethylase 1 (LSD1, also known as KDM1A) plays a pivotal role in the regulation of EMT. Here we present an overview of the causative role of LSD1 in the EMT process, summarizing recent findings on its emerging functions in cell migration and invasion in breast cancer.

LSD1和KDM5家族在卵巢癌细胞中的表达及LSD1对细胞增殖迁移的影响

目的:研究赖氨酸特异去甲基化酶1(LSD1)和赖氨酸去甲基化酶5家族(KDM5家族成员)在人卵巢癌细胞中的表达,分析LSD1对细胞增殖迁移的影响。方法:在3种卵巢癌细胞株中,分别用RT-PCR检测LSD1、KDM5A、KDM5B、KDM5C、KDM5D的mRNA的表达,蛋白质印迹法检测前4种酶的表达;在人正常卵巢上皮细胞和癌细胞株中,采用蛋白质印迹法检测LSD1的表达;用MTT法检测LSD1对卵巢癌细胞株增殖的影响;应用划痕试验检测LSD1对卵巢癌细胞株迁移的影响。结果:在3种人卵巢癌细胞的上述5种酶中,LSD1表达水平最高(P<0.01),KDM5家族成员在不同细胞系中差异表达。LSD1抑制剂反苯环丙胺处理卵巢癌细胞后,用MTT法发现抑制LSD1能显著降低癌细胞增殖(P<0.05),刮痕实验发现该药物可显著抑制卵巢癌细胞的迁移(P<0.05)。结论:LSD1在卵巢癌中高表达,KDM5家族差异化表达;LSD1与卵巢癌细胞系的增殖和迁移能力密切相关。

赖氨酸特异性去甲基化酶1在食管鳞癌中的表达及其临床意义

目的检测赖氨酸特异性去甲基化酶1(Lysine specific demethylase 1,LSD1)在食管鳞癌以及正常食管组织中的表达,并探讨LSD1与食管鳞癌临床特征、肿瘤增殖及凋亡等的关系。方法免疫组化S-P染色法检测86例食管鳞癌组织及29例正常食管组织中LSD1、增殖相关抗原Ki67的表达情况,TUNEL检测食管鳞癌组织凋亡情况,并分析LSD1表达与患者临床资料、预后以及增殖和凋亡的关系。结果 LSD1在食管鳞癌组织中阳性率(89.5%)明显高于正常组织(51.7%),且与患者淋巴结转移相关(P<0.05),并能明显影响患者的预后(P<0.05),LSD1的表达与肿瘤增殖有关,但与凋亡无关。结论 LSD1在食管鳞癌中高表达且与患者预后相关,可能成为食管鳞癌中值得研究的治疗靶标。

2-甲基-2-取代-7-羟基-2,3-二氢-4H-1-苯骈吡喃-4-酮及其

目的:对自行设计的抗真菌先导化合物进行衍生物合成和抗真菌活性研究,以验证设计思想,检验模建结果的可靠性。方法:设计合成18个化合物,所有目标化合物经元素分析、1HNMR谱和红外光谱确证,部分化合物还进一步用13CNMR谱、MSEI谱和高分辨质谱确证。用8种人类致病真菌对所有目标化合物测试体外最小抑菌浓度值。结果:合成的18个化合物中,14个(JS1b～d,JS2a～d,JS3a～b,JS4a～d和JS5c)为新化合物。结论:对所合成的化合物进行抗真菌活性测试,结果表明设计合成的衍生物的抗真菌活性变化规律与设计思想吻合,从配体角度验证了模建的靶酶三维结构的可靠性,检测了活性位点力场的分布。

赖氨酸特异性去甲基化酶1在肿瘤领域的研究进展

赖氨酸特异性去甲基化酶1(LSD1)是第一个被发现的赖氨酸特异性脱甲基酶,其可以特异地去除组蛋白H3第4位赖氨酸(H3K4)和组蛋白H3第9位赖氨酸(H3K9)的二甲基和一甲基修饰,调控靶基因的表达。LSD1在肿瘤的发生、增殖、侵袭转移过程中均发挥了重要作用,有望成为肿瘤治疗的新的分子靶标。本文就LSD1在肿瘤领域的研究进展作一综述。

抑制LSD1酶活性对HBV模型小鼠的作用

目的研究组蛋白赖氨酸去甲基化酶1(LSD1)酶活性下降对乙型肝炎病毒(HBV)模型小鼠的作用。方法尾静脉高压注射重组HBV1.3质粒建立HBV小鼠模型;将雌性BALB/c小鼠随机分为正常组、模型组、LSD1小干扰RNA(siRNA)处理组和反苯环丙胺(TCP)治疗组。取各组小鼠外周血,通过酶联免疫吸附试验、全自动微粒子化学发光法和Real-Time PCR检测小鼠体内乙肝表面抗原(hepatitis B surface antigen,HBsAg)和HBV DNA的表达;免疫组织化学法检测HBsAg在肝脏中的分布;Western blotting检测小鼠脾淋巴细胞LSD1的表达。结果 HBV模型小鼠造模成功;LSD1 siRNA处理组和TCP治疗组小鼠HBsAg、HBV DNA和LSD1的表达水平均较模型组明显下降(P<0.01),肝组织中HBsAg的分布也明显减少。结论抑制LSD1酶活性对HBV模型小鼠体内HBV的清除有一定的作用。

LSD1及其在肿瘤发生中的调节作用

赖氨酸特异性组蛋白去甲基化酶(LSD1)是一种黄素腺嘌呤二核苷酸依赖性单胺氧化酶,可以特异性地催化单甲基化和二甲基化的组蛋白H3第4位赖氨酸(H3K4me1、H3K4me2)及第9位赖氨酸(H3K9me1、H3K9me2)去甲基化,从而调节基因的转录活性。近年来功能研究发现LSD1通过调节靶基因的表达,在肿瘤的发生、胚胎分化、异染色质的形成以及诱导多能干细胞形成等多方面起到重要作用。现对LSD1的结构、作用方式以及与肿瘤发生的关系等方面进行综述。