首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
From ontogeny of tapetum in Anemarrhena asphodeloides, the ultrastructnral features of tapetal cells are as follows: 1. The profuse rough endoplasmic reticula are often closely associated with lipid bodies and vesicles, and linking each other into compound organelles. This is one of the striking features in Anemarrhena tapetal cell. 2. After meiosis of the micro- spore mother cell, the tapetal cytoplasm contains a large number of vesicles, in which the electron opaque substances are accumulated. Then they fuse to form a large zone of storage material similar to lipid bodies. Before accumulation of opaque material, these vesicles in the tapetal cytoplasm are larger than those in elaioplast (see Plate II, Fig. 2). 3. During stage of pollen maturation the tapetal cytoplasm becomes disorganized and the cells are almost occupied by the elaioplasts at various degree of development. On the basis of the report of Dickinson (1973), the formation of a pollen coatings of Lilium is different from that of Raphanus. The osmiophilic bodies in the former have originated from membrane lamellae or membranous system of plastid, and those in the latter are formed from the plastid vescles. It is intereting to note that the mode of origin of the plastid osmiophilic bodies in Anemarrhena is rather similar to that of Raphanus than to Lilium. About the origin of the pro-Ubisch bodies in tapetal cytoplasm of Anemarrhena studies revealed that a large number of the medium electron dense bodies appear in the tapetal cytoplasm. This is the first sign of the formation of the pro-Ubisch bodies and its character is very similar to spherosome in many respects. From many ultrasections, it can be seen that the ER profile is closely associated with the pro-Ubisch bodies. Thus we can conclude that the proubisch bodies of Anemarrhena are derived from rough endoplasmic reticulum. Although Heslop-Harrison et al. (1969) has considered that the compound Ubisch bodies do not occur in Lilium, there are prominent aggregation of Ubisch bodies in Anemarrhena, same as reported in Oxalis (Cariel, 1967), Silene (Heslop-Harrison, 1963a) and Helleborus (Echlin et al., 1968). After investigation on certain angiosperm in 1972, Gupta and Nanda have reported that the peritapetal membrane belonging to tapetum of secretory type lies against the inner tang- ential wall; in the plasmodial type of tapetum, it is formed on the outer tangential wall. But in some species of Poaceae and Solanaceae, the peritapetal membrane is formed on both sides of the tapetal cells (Banerjee, 1967; Reznickov & Willemse, 1980). In the secretory tapetum of Anemarrhena, the peritapetal membrane, which do not comply with the conclusion of Gupta & Nanta (1972), is formed on outer tangential wall.  相似文献   

2.
Sarsasapogenin, a kind of mainly effective components of Anemarrhena asphodeloides Bunge (Liliaceae) has the effects of being anti-diabetes and improving memory. However, there are few reports focusing on its anti-tumor effects. In this study, the sarsasapogenin was extracted from rhizomes of A. asphodeloides Bunge and applied to inhibit HepG2 human hepatoma cells. MTT assay showed that sarsasapogenin induced a distinct dose- and time-dependent diminution of cell viability with IC(50) of 42.4+/-1.0microg/ml for 48h. Furthermore, sarsasapogenin-induced apoptosis of HepG2 cells was verified by Hoechst 33258 staining, electron microscopy, DNA fragmentation and PI staining. Flow cytometry analysis showed that sarsasapogenin-induced cell apoptosis was through arrest of cell cycle in G(2)/M phase. Hence we proposed that sarsasapogenin could be used as an anti-liver cancer drug for future studies.  相似文献   

3.
杨楠  聂江力  辛微  夏徐  郎玉洁  裴毅 《植物研究》2019,39(2):246-251
以知母(Anemarrhena asphodeloides)种子为材料,分别采用1%、2%、4%、6%浓度的EMS处理6、8、12和24 h,在恒温培养箱内进行种子萌发实验,研究不同浓度的化学诱变剂甲基磺酸乙酯(ethyl methane sulfonate,EMS)处理对知母种子萌发的影响,筛选适宜的诱变浓度和诱变时间。结果表明:随EMS浓度的增加和处理时间的延长,知母种子发芽率呈现逐渐降低的趋势,以相对发芽率达到半致死浓度为标准,6%EMS浸种12和24 h可作为EMS诱导知母建立突变体库的适宜条件。  相似文献   

4.
Three known phenolic compounds, (-)-(R)-nyasol (= 4,4'-(1Z,3R)-Penta-1,4-diene-1,3-diyldiphenol; 1), its derivative 2, and broussonin A (3)--isolated from the rhizomes of Anemarrhena asphodeloides--were for the first time identified as the active principles capable of efficient respiratory-syncytial-virus (RSV) inhibition. The IC50 values of 1-3 against the RSV-A2 strain, propagated in HEp-2 cells, were determined, their activities being higher than that of the standard antiviral drug ribavirin (IC50 = 1.15 microM). In addition, the known, but inactive, compound 'trans-N-(para-coumaroyl)tyramine' (= (2E)-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl)ethyl]prop-2-enamide; 4) was isolated from this plant for the first time.  相似文献   

5.
PCR方法扩增人基质金属蛋白酶 2 (MMP 2 )不含信号肽的表达序列 ,酶切和测序鉴定正确后 ,构建酵母重组表达质粒pPIC9 MMP 2 ,电击法转化毕赤酵母 (Pichiapastoris)细胞得到阳性克隆 ,甲醇诱导获得含大量基质金属蛋白酶 2的培养上清 ,经SephacrylS 2 0 0纯化后 ,纯度达到电泳纯。明胶酶谱和SDS PAGE分析说明重组MMP 2能够降解明胶和IV型胶原 ,表明重组蛋白具有与天然MMP 2相似的底物特异性。糖基化分析和SDS PAGE表明 ,表达产物的分子量约为 5 0kD ,重组MMP 2的C 末段可能发生了降解。  相似文献   

6.
Oxidative stress due to the over-production of reactive oxygen species (ROS) is associated with human skin aging. This study was designed to identify the bioactive phenolics in detoxified Rhus verniciflua Stokes (DRVS) that may protect human skin against oxidative stress. Under oxidative stress caused by H2O2, the 40% (v/v) aqueous methanol extract of DRVS protected human keratinocytes in a dose-dependent manner. The expression of matrix metalloproteinase-1 (MMP-1) was also inhibited by the DRVS extract in human dermal fibroblasts-neonatal cells exposed to ultraviolet A. The major bioactive phenolics of DRVS were tentatively identified by LC/Q-TOF-ESI-MS/MS, and included gallic acid, 2-(ethoxymethoxy)-3-hydroxyphenol, fustin, a fustin isomer, tetragalloyl glucose, pentagalloyl glucose, fisetin, sulfuretin, a sulfuretin isomer, and butein. The results suggest that a DRVS extract may be effective in slowing skin aging through its antioxidative properties and by down-regulating MMP-1 expression. Further studies are needed to examine whether this effect would be mediated by the phenolics identified in this study.  相似文献   

7.
目的:研究基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)及其组织抑制因子-1(tissue inhibitor of metallopmteinase—1,TMP-1)在进展期胃癌中的表达情况,探讨二者的表达与胃癌侵袭转移闻的关系及二者间的联系。方法:应用免疫组化方法检测70例进展期胃癌标本中MMP-9,TIMP-1的表达,并进行回顾性随访。结果:馒反肌层以上者MMP-9的阳性表达(66.67%)明显高于肿瘤局限于粘膜、粘膜下者(20%P〈0.01)。MMP-9阳性表达与胃癌的淋巴转移与肝转移有相关性(P〈0.01)。TIMP-1的表达随胃癌浸润深度增加而减少,当肿瘤突破浆膜时TIMP-1的表达呈现陡降趋势(P〈0.01)。结论:MMP-9的过阳性表达和TIMP-1的表达失衡可能与胃癌转移行为有关。TIMP-1可能抑制胃癌的浸润转移。  相似文献   

8.
为探讨利用培养的骨骼肌细胞表达人基质金属蛋白酶的可行性,利用PCR和DNA重组技术构建人mmp-9-myc-his/pcDNA3基因表达载体,转染成肌细胞QM-7,G418筛选阳性转染子.诱导细胞分化成肌管后,收集细胞培养上清.经Western印迹检测,表达产物分子量为93kD,与蛋白标准品对照推测表达量约10~15mg/L.利用Ni-NTA琼脂糖从1L培养上清中纯化到4~6mgMMP-9纯品,纯化效率约50%.经明胶酶谱检测,表达蛋白可以降解明胶.这些结果表明所表达的MMP-9具有生物活性,为以MMP-9为靶分子的特异拮抗剂和/或药物的筛选、MMP-9定量检测试剂盒的开发以及MMP-9的功能研究奠定了基础;以鹌鹑成肌细胞QM-7作为外源蛋白脊椎动物细胞表达体系具有表达量高、经济等优点,有可能进一步研究开发成为新的外源重组蛋白脊椎动物细胞表达体系.  相似文献   

9.
目的:观察羌活地黄汤对大鼠佐剂性关节炎软骨中基质金属蛋白酶-1(marxmetalloproteinase-1,MMP-1)、基质金属蛋白酶-13(matrixmetalloproteinase.13,MMP-13)及基质金属蛋白酶抑制剂-1(tissueinhibitorofmetalloprotease-1,TIMP-1)表达的影响。方法:Wistar大鼠32只,随机分为正常对照组、模型组、雷公藤对照组、羌活地黄汤组。制作大鼠佐剂性关节炎模型,造模第14天开始给药。羌活地黄汤组予混有羌活地黄汤的颗粒饲料,雷公藤组给予混有雷公藤多甙的饲料,正常组及模型组均给予普通饲料。第28天分别取各组胫骨平台关节软骨,采用免疫组织化学染色测定软骨中MMP-1、13及T1MP—1表达的阳性指数。结果:模型组MMP-1、MMP-13及TIMP—1表达的阳性指数水平明显高于正常组,差异有统计学意义(P〈0.01),羌活地黄汤组MMP-1、13及TIMP-1表达阳性指数低于模型组,差异有统计学意义(P〈0.05)。结论:羌活地黄汤可能是通过调控软骨细胞外基质中MMP.1、MMP—13及TIMP-1表达变化而维持软骨的动态平衡,从而延缓RA骨骼破坏。  相似文献   

10.
胚胎植入和胎盘形成涉及细胞外基质的降解和重建,以及细胞的增殖、凋亡、迁移和分化,基质金属蛋白酶 (MMPs) 是参与这些事件的主要蛋白水解酶系统 . MMP-26 是近年来发现的 MMPs 家族的新成员,但其功能所知甚少 . 通过半定量 RT-PCR 、免疫组织化学、荧光免疫细胞化学等手段,发现人胎盘中 MMP-26 主要定位于绒毛滋养层细胞,在绒毛间质细胞中也有少量表达 . 妊娠早期,胎盘中 MMP-26 表达水平较高,至妊娠中期降至最低,但在足月胎盘中其表达又有显著提高,提示 MMP-26 可能参与妊娠早期滋养层细胞的侵润和分娩时的胎盘剥离 . 体外培养的妊娠早期人细胞滋养层细胞能产生一定水平的 MMP-26 ,而其表达受到激活素 A 的剂量依赖性刺激,表明滋养层细胞中存在 MMP-26 表达的自分泌 / 旁分泌调节 .  相似文献   

11.
12.
研究凝血酶对人脐静脉内皮细胞表达基质金属蛋白酶的影响及重组水蛭素的作用。将原代培养人脐静脉内皮细胞(HUVEC)的第2~5代分组后与凝血酶(4.0ku/L)共同温育,同时分别加入水蛭素(6.0ku/L)和肝素(6.0ku/L),在不同时间,用逆转录聚合酶链反应和免疫组织化学分析的方法评价基质金属蛋白酶-2的表达情况。结果显示凝血酶促进血管内皮细胞产生和活化基质金属蛋白酶-2。重组水蛭素可以有效地阻断凝血酶的上述作用。  相似文献   

13.
目的:探讨MMP-3和TIMP-3在人胃癌组织中的表达及其意义.方法:根据胃癌的病理大体分型将40例胃癌组织分为早期组和晚期组.其中,早期组同时不伴有淋巴结转移,晚期组伴有淋巴结转移.采用光镜、透射电镜和免疫组化方法对这两组胃癌组织的超微结构,MMP-3,TIMP-3表达和MMP-3/TIMP-3的比值进行检测.结果:MMP-3和TIMP-3主要表达于癌细胞胞浆内.早期组MMP-3阳性表达细胞较少,晚期组阳性细胞较多,二者数密度和面密度比较,具有统计学意义(P<0.01);早期组TIMP-3阳性表达细胞较多,晚期组阳性细胞较少,二者比较,具有统计学意义(P<0.01)MM-3/TIMP-3的比值在胃癌晚期较早期增大,具有统计学意义(P<0.01);电镜观察显示胃癌早期淋巴细胞浸润较多,癌细胞穿基膜不明显,晚期则淋巴细胞浸润较少,癌细胞穿基膜明显.结论:MMP-3,TIMP-3的表达程度和MMP-3/TIMP-3的比值可作为判定胃癌的侵袭和转移的指标,对其预后的判断具有参考价值.  相似文献   

14.
Abstract: Matrix metalloproteinase-9 (MMP-9) is secreted from cells and, once activated, is thought to degrade collagen in the extracellular matrix. Because collagen is not readily localized where neurons have been shown to produce MMP-9 in the human brain, the ability of this enzyme to degrade bioactive peptides was investigated with representative tachykinin peptides [substance P (SP), neurokinin A, neurokinin B, and kassinin]. Latent MMP-9 (94 kDa) was purified from the human cell line HL-60 and converted to an intermediary active form (84 kDa) with p -aminophenylmercuric acetate. This active form of MMP-9 degraded SP with a k cat/ K m of 170 m M −1 min−1, which is 30-fold greater than the previously reported value for a representative collagen-derived peptide. The major digestion products were identified as SP1–6 and SP7–11, which were derived from cleavage of the Gln6-Phe7 bond. Minor products were also generated from cleavage of the Gly9-Leu10 bond. The other representative tachykinin peptides were cleaved at rates >10-fold slower than that of SP. The 84-kDa peptidase was also active as a gelatinase. Longer treatment of MMP-9 with p -aminophenylmercuric acetate caused the conversion of the 84-kDa enzyme to the established 68-kDa active form; however, the rate of SP degradation did not increase. Because MMP-9 is produced by neurons of the CNS, these results suggest a possible regulatory role for the enzyme in intercellular communication by altering the availability of bioactive peptides.  相似文献   

15.
16.
17.
Myocardial infarction (MI) commonly leads to cardiomyocyte apoptosis and heart failure. Mangiferin is a natural glucosylxanthone extracted from mango fruits and leaves, which has anti-apoptotic and anti-inflammatory properties in experimental cardiovascular diseases. In the present study, we investigated the role and detailed mechanism of mangiferin in MI. We used ligation of the left anterior descending coronary artery to establish an MI model in vivo, and cardiomyocyte-specific Sirt1 knockout mice were used to identify the mechanism of mangiferin. For in vitro studies, oxygen and glucose deprivation (OGD) was used to mimic ischaemia in H9c2 cardiomyocytes. In mice, mangiferin treatment increased Sirt1 expression after MI, significantly reduced the infarct area, and prevented MI-induced apoptosis and heart failure. Mangiferin reduced OGD-induced cellular apoptosis in H9c2 cells. Meanwhile, Sirt1 knockout/silencing abolished the protective effects of mangiferin. Further studies revealed that mangiferin increased FoxO3a deacetylation by up-regulating Sirt1, thus preventing apoptosis, and adenovirus-mediated constitutive acetylation of FoxO3a restricted the anti-apoptotic effects of mangiferin in vivo and in vitro. Our results indicate that mangiferin prevents cardiomyocyte apoptosis and the subsequent heart failure by activating the Sirt1/FoxO3a pathway in MI, and suggest that mangiferin may have an interesting potential in following studies towards clinical evaluation.  相似文献   

18.
Matrix metalloproteinase-8 (MMP8) has been shown to influence various cellular functions. As monocytes and macrophages (Mφ) express MMP8, we investigated if MMP8 played a role in macrophage differentiation and polarization. MMP8 expression was significantly increased during monocyte differentiation into Mφ. Monocyte-derived Mφ from MMP8-deficient mice expressed higher levels of M1-Mφ markers but lower levels of M2-Mφ markers than monocyte-derived Mφ from wild-type mice. Although Mφ from either MMP8-deficient or wild-type mice were inducible by interferon-γ into M1-Mφ, only wild-type Mφ but not MMP8-deficient Mφ could be induced into M2-Mφ by interleukin-4. However, MMP8-deficient Mφ exposed to conditioned culture media of wild-type Mφ developed a M2-Mφ phenotype. Compared with conditioned culture media of wild-type Mφ, conditioned culture media of MMP8-deficient Mφ contained a lower concentration of active transforming growth factor-β (TGF-β), an M2-Mφ inducer. Moreover, evidence also showed that the degradation of the TGF-β sequester, fibromodulin, was modulated by MMP8. The data indicate a previously unknown role of MMP8 in M2-Mφ polarization by cleaving fibromodulin and therefore increasing the bioavailability of the M2-Mφ inducer TGF-β.  相似文献   

19.
目的:探讨幽门螺杆菌(HP)感染性胃癌组织中细胞周期蛋白D1(cyclinD1)、基质金属蛋白酶-9(MMP-9)的表达及其临床意义。方法:选取2016年12月到2018年6月期间在兰州大学第一医院接受治疗的胃癌患者80例,收集其手术切除的病理组织。采用C-14呼气试验和改良Giemsa染色检测患者HP感染的情况,采用免疫组化法检测胃癌组织中cyclinD1、MMP-9表达情况。分析HP感染、cyclinD1、MMP-9表达与胃癌患者临床病理特征的关系,并分析胃癌患者HP感染与cyclinD1、MMP-9表达的相关性。结果:80例胃癌患者HP感染阳性56例(70.00%),阴性24例(30.00%)。有淋巴结转移、浸润深度为T3+T4的胃癌患者的HP感染阳性率高于无淋巴结转移、浸润深度为T1+T2的胃癌患者(P0.05)。80例胃癌患者cyclinD1阳性表达45例(56.25%),阴性表达35例(43.75%),MMP-9阳性表达65例(81.25%),阴性表达15例(18.75%),TNM临床分期为III+IV期、分化程度为低分化、有淋巴结转移、浸润深度为T3+T4的胃癌患者的cyclinD1、MMP-9阳性表达率明显高于TNM临床分期为I+II期、分化程度为中高分化、无淋巴结转移、浸润深度为T1+T2的胃癌患者(P0.05)。HP感染阳性患者的cyclinD1阳性表达率和MMP-9阳性表达率均明显高于HP感染阴性患者(P0.05)。Pearson相关分析显示,胃癌患者HP感染与cyclinD1、MMP-9表达均呈正相关(P0.05)。结论:胃癌患者的HP感染情况与淋巴结转移、浸润深度有关,cyclinD1和MMP-9的表达与TNM临床分期、分化程度、淋巴结转移、浸润深度有关,且胃癌患者HP感染与cyclinD1、MMP-9表达均呈正相关。  相似文献   

20.
Kim S  Kim Y  Lee Y  Cho KH  Kim KH  Chung JH 《FEBS letters》2007,581(20):3869-3874
Cholesterol is a major component of skin lipids and acts as a regulator of vesicular trafficking and signal transduction. However, the function of cholesterol on matrix metalloproteinases (MMPs) expression of human skin is not fully understood. Here, we investigated the effects of cholesterol on MMP-9 expression in normal human keratinocytes (NHK) and HaCaT cells. Basal level of MMP-9 expression was decreased by cholesterol in NHK. On the other hand, MMP-9 expression was increased by the cholesterol depletion agent, methyl-beta-cyclodextrin (MbetaCD), while it was inhibited by cholesterol repletion in HaCaT cells. MbetaCD induced ERK and JNK phosphorylation were prevented by cholesterol repletion. The inhibition of ERK and JNK decreased MbetaCD-induced MMP-9 expression. Therefore, our results suggest that cholesterol regulates MMP-9 expression through ERK and JNK-dependent pathways.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号