Muscarinic agonists for the treatment of Alzheimer’s disease: progress and perspectives

Much interest has focused on the development of selective muscarinic agonists for the treatment of Alzheimer's disease (AD). Cholinergic replacement therapy is thought to be beneficial in alleviating some of the cognitive dysfunctions in this disorder. The cholinergic neuronal tracts are involved in memory and learning processes, and the extent of the degeneration of the cortical projections correlates with the severity of the dementia. An M1 selective muscarinic agonist may be effective in treating at least some of the cognitive symptoms in AD. Highly selective M1 agonists, producing cellular excitation, should be beneficial in AD, regardless of the extent of degeneration of presynaptic cholinergic projections to the frontal cortex or hippocampus. Functional abnormalities in AD may also occur along various signal transduction pathways mediated, in part, at least, by muscarinic receptors. In general, activities associated with mAChR subtypes and m1 receptors, in particular, indicate that M1 agonists may also be useful for this aspect of AD. Mismetabolism of amyloid precursor proteins (APPs) may induce AD. Recent studies indicate that the formation of the b-amyloid peptide (Ab) and amyloid plaques is linked to the loss of cholinergic function in AD. New data on the activation of m1 mAChRs in conjunction with recent findings that the induction of such receptors stimulates neurotrophic-like activities, decreases tau phosphorylation and inhibits apoptosis indicate that restoring the cholinergic tone in AD may be useful both in improving memory function and in altering the onset and progression of AD dementia. This article focuses on the recent, promising developments in this field and assesses the value of muscarinic agonists currently under development for the treatment of AD.     

木犀草苷对人食管鳞状癌Eca109细胞生长的抑制作用及其机制

目的 研究木犀草苷对人食管鳞状癌Eca109细胞生长的抑制作用及其机制。方法 Eca109细胞经不同浓度木犀草苷处理后,MTT法检测Eca109细胞增殖;倒置显微镜观察Eca109细胞形态的变化;流式细胞术检测Eca109细胞周期变化及细胞凋亡情况;RT-PCR检测Eca109细胞cyclin D1、survivin和c-myc基因表达。结果 MTT实验表明,木犀草苷80、120、160、200、240 μmol/L对Eca109细胞均有抑制作用,且与浓度相关。木犀草苷可引起Eca109细胞形态改变、体积缩小,并与周围细胞脱离,浓度为240 μmol/L时使细胞呈出芽状,有的细胞伸出多个伪足样突起;浓度为160、240 μmol/L时,可将细胞阻滞于G₂/M期,诱导细胞凋亡;浓度为240 μmol/L并处理Eca109细胞48 h后,使Eca109细胞cyclin D1、survivin和c-myc基因表达低于对照组（P＜0.05）。结论 木犀草苷对食管鳞状癌Eca109细胞的生长有显著抑制作用,其通过改变细胞周期、诱导细胞凋亡及抑制相关基因的表达发挥抗肿瘤作用。     

壁虎粗多肽对3种消化道肿瘤细胞的体外抑制作用

目的 探讨壁虎粗多肽(GCPS)对消化道肿瘤细胞体外增殖的抑制作用.方法 用不同浓度 (0.375、0.75、1.0、1.5、3.0 mg/mL) 的GCPS处理食管癌细胞EC109、肝癌细胞HepG2和胃癌细胞MGC803,于24、48、72 h后倒置显微镜下观察细胞形态变化,并使用MTT法观察GCPS对3种人消化道肿瘤细胞增殖的影响.结果 与空白对照组比较,在倒置显微镜下可观察到GCPS作用24、48、72 h后的细胞形态有不同程度的改变.MTT法结果显示GCPS具有抑制人消化道肿瘤细胞增殖作用,且作用呈浓度和时间依赖性;48 h后GCPS作用于上述3种细胞的IC50为1.1、1.2 和1.6 mg/mL.结论 壁虎粗多肽可抑制HepG2、EC109和MGC803这3种消化道肿瘤细胞增殖.     

ABCE1基因对人食管癌细胞Eca109的影响及作用机制

目的 明确ABCE1基因对食管癌Eca109细胞中的增殖、侵袭、迁移、凋亡生物学行为的影响并对其作用机制进行初步探讨.方法 将构建好的ABCE1的SiRNA绿色荧光载体转染入食管癌Eca109细胞中,于荧光显微镜下观测转染效率并应用Western blot法及RT-PCR法证实基因沉默的效果,通过Western blot法检测RNase L的改变,MTT法分析细胞增殖能力并绘制细胞生长曲线,Transwell法检测细胞侵袭力,Transwell法检测细胞侵袭力,流式细胞术检测细胞凋亡率.结果 转染ABCE1-SiRNA后的Eca109细胞内可见绿色荧光.Western blot法及RT-PCR法证实了基因沉默的效果(P＜0.05).MTT实验证实,转染ABCE 1-SiRNA载体的食管癌细胞与阴性对照组和空白对照组的细胞相比,增殖受到显著抑制(P＜0.05).Transwell结果显示转染ABCE1-SiRNA载体的食管癌细胞穿膜细胞数较阴性对照组和空白对照组的细胞明显减少(P＜0.05).转染ABCE1-SiRNA-1和转染ABCE1-SiRNA-2的细胞与空白对照组细胞和转染ABCE1-SiRNA-N的细胞相比较,细胞迁移发生明显减慢(P＜0.05),流式细胞仪检测细胞凋亡显示转染ABCE1-SiRNA载体的细胞的细胞凋亡率均显著高于阴性对照组和空白对照组细胞(P＜0.05).结论 抑制ABCE1基因表达后,食管癌细胞的增殖、侵袭及迁移能力被抑制,细胞发生早期凋亡.这表明ABCE1基因的表达对食管癌细胞Eca109具有肿瘤生物学行为的影响.     

miR-25对食管癌EC109细胞侵袭和迁移能力的 影响及临床意义

目的 探索 miR-25 对食管癌侵袭和迁移能力的影响以及作为食管癌诊断生物标志物的潜力。方法 （1）荧光定量PCR（qPCR）检测54例早期食管癌患者癌组织和癌旁组织中miR-25表达水平。（2）人食管癌细胞EC109 分为miR-25 mimic组、NC mimic组、miR-25 inhibitor组和NC inhibitor组。转染相应序列后,qPCR检测miR-25转染 效率。Transwell实验检测过表达或敲低miR-25对EC109细胞侵袭和迁移的影响。Targetscan数据库预测miR-25的 靶基因,选定靶基因盐诱导激酶1（SIK1）基因。Western blot 和双荧光素酶报告实验鉴定miR-25与SIK1的靶向关 系。（3）EC109 细胞分为 pcDNA 3.1 组、SIK1 过表达组和 miR-25+SIK1 过表达组。Transwell 实验检测 miR-25 靶向 SIK1对EC109细胞侵袭和迁移能力的影响。（4）提取食管癌患者（54例）和健康对照者（54例）的血浆外泌体,比较2 组血浆外泌体中miR-25的相对表达量,分析食管癌患者癌组织和血浆外泌体中miR-25的相关性。结果 （1）食管 癌组织中 miR-25 相对表达水平高于癌旁组织。（2）过表达 miR-25 后,EC109 细胞侵袭和迁移能力增强,而敲低 miR-25 表达后,细胞侵袭和迁移能力下降。Western blot 结果显示,过表达 miR-25 后,SIK1 蛋白表达下降;反之, 敲低miR-25后SIK1蛋白表达升高。（3）Transwell实验显示,与pcDNA 3.1组相比,SIK1过表达组EC109细胞侵袭和 迁移的细胞数量减少,而miR-25和SIK1联合作用后,EC109侵袭和迁移的细胞数量较SIK1过表达组增多。（4）食管 癌血浆外泌体样本中miR-25的表达量高于健康对照,且miR-25在食管癌组织中的表达与血浆外泌体中的相对表达 量呈正相关。结论 miR-25可能通过靶向调控SIK1来促进食管癌细胞的侵袭和迁移,且miR-25有作为食管癌早 期诊断生物标志物的潜力。     

人食管鳞癌细胞系EC109中肿瘤干细胞的分离（富集）与鉴定

目的运用无血清成球培养法从人食管鳞癌细胞系EC109中分离/富集肿瘤干细胞,并对其＂干性＂特性进行鉴定。方法将EC109细胞接种至添加1XB27的干细胞培养基（DMEM/F12 1：1,无血清）,于poly-Hema包被的培养皿或低黏附培养板中培养,获取细胞球。采用实时定量PCR方法检测其干性相关转录因子的基因表达,连续传代和平板克隆形成实验评价其自我更新能力,免疫荧光细胞化学法检测其分化前后干性相关转录因子和分化标志物的表达变化,以裸鼠移植瘤实验检测其体内成瘤能力。结果培养5d能获得EC109细胞的细胞球。细胞球细胞高表达Oct4等干性相关转录因子,具有自我更新能力、分化潜能。裸鼠体内1×104个细胞球细胞能启动肿瘤形成,而单层培养细胞则需要1×105个细胞,且同数量级的细胞球细胞较单层培养细胞所形成的肿瘤体积大。结论无血清成球培养法能从食管鳞癌细胞系EC109获得细胞球,细胞球富集了肿瘤干细胞。     

New drugs being developed for the treatment of tuberculosis

More than one-third of the world is infected with tuberculosis (TB) and 5000 people die of TB everyday. Of the many diarylquinolones shown to be effective at inhibiting the multiple-cycle growth of Mycobacterium tuberculosis, R-207910 was the most active and was chosen as the lead compound. In the non-established infection mouse TB model, a single dose of R-207910 50 mg/kg had a bacteriostatic effect, and a bactericidal effect was observed at 100 mg/kg. In the established infection mouse model, treatment was started 12 – 14 days after infection, and when added to the triple therapy of isoniazid, rifampin and pyrazinamide or substituted for any component of the triple therapy, R-207910 increased the effectiveness. As ethambutol is chemically simple, and only has modest potency in treating TB, it was considered to be amenable to optimisation by combinatorial chemistry, and from the analogues synthesised that inhibited the growth of M. tuberculosis, SQ-109 was eventually selected as the lead compound for further testing. In female mice infected with M. tuberculosis H37Rv by tail-vein injection, treatment with SQ-109 25 mg p.o. initiated 20 days later for 5 days/week for 4 weeks reduced the counts by 1.87 log units, which was slightly more than with ethambutol 100 mg (1.67 log units). These results indicate that exciting new drugs are under development for the treatment of TB.     

桥接整合因子1 去甲基化诱导细胞周期阻滞抑制食管鳞状细胞癌EC109细胞增殖

目的：分析桥接整合因子1（bridging integrator-1, Bin1）去甲基化对Bin1 基因表达和食管鳞状细胞癌EC109 细胞增殖能力的影响,并初步探讨其可能的作用机制。方法：甲基化特异性PCR（methylation specific polymerase chain reaction, MSP）法检测去甲基化药物5-氮杂-2''脱氧胞苷（5-Aza-2''-deoxycytidine, 5-Aza-dc）处理后EC109 细胞Bin1 启动子区域的甲基化状态,用qPCR、Western blotting 和MTT法分别检测单独5-Aza-dc 和5-Aza-dc 加转染Bin1 基因干扰片段（Bin1 siRNA）处理对EC109 细胞Bin1 mRNA及其蛋白表达和细胞增殖能力的影响,流式细胞术和Western blotting 检测5-Aza-dc 处理后EC109 细胞周期和细胞周期相关蛋白（Cyclin D1 与CDK4）表达的变化。结果：去甲基化药物5-Aza-dc 处理后,EC109 细胞Bin1 基因启动子区域发生去甲基化。5-Aza-dc 处理的Bin1 去甲基化EC109 细胞Bin1 mRNA和蛋白表达明显上调（均P<0.05）,细胞增殖能力明显下降（P<0.05）,细胞阻滞在G0/G1 期,表现为S 期细胞比例显著减少,细胞周期相关蛋白Cyclin D、CDK4 表达均明显下调（均P<0.05）。Bin1 去甲基化EC109 细胞转染Bin1 siRNA后,Bin1 mRNA和蛋白表达明显下调,细胞增殖能力增强（均P<0.05）。结论：Bin1 基因启动子区域在EC109 细胞中呈完全甲基化状态,5-Aza-dc 去甲基化可使食管鳞癌细胞EC109 细胞Bin1 表达升高,通过降低细胞周期相关蛋白表达诱导细胞周期阻滞抑制EC109 细胞增殖。证实表观遗传学变化可能与食管癌细胞恶性增殖有关,可为食管癌治疗提供新的思路。     

shRNA沉默HMGA2对食管癌ECA109细胞增殖和凋亡的影响

目的 探讨shRNA沉默HMGA2对食管癌ECA109细胞增殖、凋亡、迁移和侵袭的影响,并探究所涉及的相关机制.方法 构建针对人HMGA2基因的shRNA表达载体,瞬时转染至人食管癌细胞系ECA109中,24 h后应用蛋白免疫印迹法(WB)检测转染效率;应用MTT法比较转染后sh-HMGA2组与sh-NC组细胞增殖情况;应用流式细胞术检测HMGA2沉默对细胞凋亡的影响;应用Transwell测定评估HMGA2沉默对细胞迁移和侵袭能力的影响;应用WB检测HMGA2沉默对ECA109细胞内HMGA2、TGF-βRⅡ、Vimentin、Smad2、Smad3、磷酸化Smad2/3、E-cadherin、N-cadherin、Bax、Bcl-xl、MMP-2、MMP-9蛋白表达的影响.结果 与sh-NC组相比,sh-HM-GA2组中HMGA2的蛋白表达水平降低(P﹤0.05).MTT结果显示,与sh-NC组相比,sh-HMGA2组细胞增殖率明显降低(P﹤0.01).流式细胞术结果显示,与sh-NC组相比,sh-HMGA2组细胞凋亡率增加(P﹤0.05).Tran-swell测定结果显示,与sh-NC组相比,sh-HMGA2组中ECA109细胞迁移和侵袭数量均减少(P﹤0.05).WB结果显示,与sh-NC组相比,sh-HMGA2组细胞内Bax和E-cadherin表达水平增加,而Bcl-xl、Vimentin、N-cadherin、MMP-2、MMP-9、TGF-β、Smad2、Smad3、p-Smad2/3蛋白表达水平均降低(P﹤0.05).结论 shRNA沉默HMGA2基因通过下调Bcl-xl表达、上调Bax表达水平来抑制食管癌细胞系ECA109细胞增殖并促进细胞凋亡,并通过抑制MMP及上皮间质转化来抑制细胞迁移和侵袭,这一过程涉及TGF-β/Smad信号通路.     

Profiling of sperm proteins and association of sperm PDC-109 with bull fertility

Abstract

The composition of sperm proteins influences the fertilizing ability of sperm and hence the present study was conducted (i) to profile sperm proteins expression patterns in bulls of differing fertility index and (ii) to identify and relate the abundant sperm proteins with bull fertility. The semen samples were collected from Holstein-Friesian bulls (n?=?12) varying in conception rate (CR) (high/low). The frozen semen straws (three ejaculates, from each bull) were used to study (a) sperm kinetic parameters, (b) plasmalemma integrity, (c) mitochondrial membrane potential, and (d) chromatin distribution. Three bulls were randomly selected from each group (n?=?3) and the neat sperm pellets were subjected to percoll purification, followed by protein isolation using 0.1% Triton X100. The sperm kinetic parameters, plasmalemma integrity, mitochondrial membrane potential, and the chromatin distribution did not differ significantly between groups. The number of acidic (pI; 3.1–5.6, 37%) and basic (pI; 7.9–10.0, 27%) proteins and their pattern of expression varied significantly (p?<?0.05) between high and low fertile bulls. The abundant sperm protein spots in 2D-gel electrophoresis (2DE) were identified as seminal plasma protein PDC-109 (i.e., protein with N-terminus aspartic acid, D and carboxy terminus cystine, having 109 amino acids) and its isoform and spermadhesin-1 (SPADH1). The western blot analysis confirmed the presence of PDC-109 isoform proteins at 15.4?kDa (pI 5.3 and 5.5). The seminal plasma protein PDC-109 was abundant in the low fertile when compared to the high fertile group (p?<?0.05). This study suggests that the imbalance in acidic and basic sperm proteins may influence sperm fertility and sperm PDC-109 levels above a certain threshold affects bull fertility.