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天下生命科学前沿动态周报(二)
（03.29--04.04 / 2010）
一竞技国际集团:陶国新
本周的希望大多是关于基因治疗方面的。 其中发明控制涡虫再生能力“总开关” 的报道较量有意义。关于我们相识动物的再生有很好的启示。另外两篇有关多巴胺D2受体的文章在基因层面上看到了其对吃垃圾食物和睡眠的影响，关于养生保健或许有所资助。其余是有关基因疗法的一些希望和基因运载的新手艺，基因与朽迈、免疫的关系等。
1. 发明控制涡虫再生能力“总开关”
【摘要】
一种名叫“涡虫”的扁形虫纵然被切成百段，一两周后每段都会再生出完整的涡虫。涡虫这种超强再生能力一直是科学家感兴趣的研究课题。近年来对涡虫最感兴趣的是从事干细胞研究的科学家，由于研究发明，涡虫再生的神秘在于其体内有一种散布全身的全醒目细胞，其分解能力类似人类胚胎干细胞。有所差别的是，涡虫这种干细胞能在任何时间分解成其他任何种类的细胞。涡虫的身体被切断后，它体内散布在各处的这些干细胞能转酿成神经、肌肉、肠等种种组织细胞，重新长出那些失去的部分。
德国科学家最近发明了一种对涡虫的再生能力有要害调理作用的卵白质。他们希望这一发明有助于人类干细胞研究。 德国马克斯•普朗克分子生物研究所科学家用核糖核酸（RNA）滋扰抑制基因表达的方法抑制了涡虫体内卵白质“Smed—SmB”的合成，效果发明这导致涡虫体内的全醒目细胞均不可破碎，涡虫因此失去了再生能力。加入研究的科学家说，这相当于发明了影响涡虫干细胞破碎的“总开关” ，这一发明可能有助于人们深入相识组织缺损修复的机理。由于涡虫细胞中四分之三的基因与人类基因相似，科学家还希望他们的研究效果有助于人类干细胞研究。新华网 宣布时间：2010-4-1 16:12:39
【点评】
若是能证实关闭其它基因涡虫依然能再生的话，那么Smed-Smb卵白就很可能是个涡虫全效生长因子。若是能在哺乳动物体内发明类似功效的卵白，那将是很是惊人的�；蛐硪痪杭荚偕镏世镉欣嗨乒πУ囊蛩兀�？ 团结上期的“发明哺乳动物控制再生能力基因”关闭p21，开启再生的报道，一对掌控再生能力的基因开关就泛起了: p21抑制再生，表达Smed-Smb类似卵白的基因增进再生。 而生长有用的 RNAi 手艺来按需要关闭对应基因可以抵达增进或抑制再生的目的。不过看起来离这个效果还很远。可是关于进一步相识动物的再生气理是有资助的。
【原文摘录】
doi: 10.1242/dev.042564 April 1, 2010 Development 137,1055-1065.
Smed-SmB, a member of the LSm protein superfamily, is essential for chromatoid body organization and planarian stem cell proliferation
Enrique Fernandéz-Taboada1, Sören Moritz2, Dagmar Zeuschner2, Martin Stehling2, Hans R. Schöler2,3, Emili Saló1,* and Luca Gentile2,*
Planarians are an ideal model system to study in vivo the dynamics of adult pluripotent stem cells. However, our knowledge of the factors necessary for regulating the ‘stemness’ of the neoblasts, the adult stem cells of planarians, is sparse. Here, we report on the characterization of the first planarian member of the LSm protein superfamily, Smed-SmB, which is expressed in stem cells and neurons in Schmidtea mediterranea. LSm proteins are highly conserved key players of the splicing machinery. Our study shows that Smed-SmB protein, which is localized in the nucleus and the chromatoid body of stem cells, is required to safeguard the proliferative ability of the neoblasts. The chromatoid body, a cytoplasmatic ribonucleoprotein complex, is an essential regulator of the RNA metabolism required for the maintenance of metazoan germ cells. However, planarian neoblasts and neurons also rely on its functions. Remarkably, Smed-SmB dsRNA-mediated knockdown results in a rapid loss of organization of the chromatoid body, an impairment of the ability to post-transcriptionally process the transcripts of Smed-CycB, and a severe proliferative failure of the neoblasts. This chain of events leads to a quick depletion of the neoblast pool, resulting in a lethal phenotype for both regenerating and intact animals. In summary, our results suggest that Smed-SmB is an essential component of the chromatoid body, crucial to ensure a proper RNA metabolism and essential for stem cell proliferation.
2. 垃圾食物成瘾症或确实保存
【摘要】
美国最新研究显示，肥胖人群无法拒绝美食诱惑的诠释可能并不是给自己找捏词，垃圾食物成瘾症似乎确实保存。 这一发明是通过老鼠研究得出的。在研究职员无限制地为老鼠提供熏肉、磅饼、糖块以及其它垃圾食物等高热量食物之后，老鼠体重快速增添。随着身体越来越胖，吃工具酿成一种强迫，纵然这么做双脚会遭受电击，它们也不肯意放下爪子，继续享用美食。相比之下，享用康健食物的老鼠并未增添太多体重，在意识到吃的过多会遭到电击之后，它们便阻止进食。研究职员指出，更令人感应受惊的是，在拿走肥胖老鼠的垃圾食物并换上康健食物之后，这些家伙居然选择绝食。在长达两周时间里，它们拒绝吃任何工具。研究职员尚无法确定研究效果是否也适用于人类。
在对胖老鼠的大脑举行剖析时，研究职员发明多巴胺D2受体镌汰。凭证此前举行的研究，这种受体与可卡因和海洛因成瘾有关�？夏崴担骸岸抉囊桓霰昙蔷褪堑贾麓竽钥浣毕低呈虑榛票⒆�。”在人工抑制其他老鼠脑中的这种受体之后，这些老鼠也最先情不自禁地转向垃圾食物。波士顿大学医学院成瘾症实验室助理教授皮埃特罗•科特纳体现，一直群集的脂肪中的一些物质也会改变大脑的夸奖阈限，进而形成一个恶性循环——只有吃得更多，才华获得知足感�？铺啬伤担骸盎氐秸Ｗ刺奈ㄒ环椒ň褪呛憔媒谑场蕴逯赝辈辉俪岳澄�。”他与同事此前举行的研究显示，让老鼠挣脱高热量食物可能导致大脑泛起与戒毒和戒酒类似的转变。
【点评】
多巴胺相关的大脑夸奖系统事情机制由于成瘾行为而爆发改变，多巴胺D2受体镌汰。该文老鼠实验显示，现在这类成瘾行为行列里很可能又加入了吃垃圾食物。再生育生的康健食谱扫除了这种成瘾行为，预防大脑夸奖系统事情机制的异常改变，维持康健的大脑功效。团结下篇的多巴胺D2受体剔除小鼠的睡眠研究，可以推测，垃圾食物成瘾的人很可能的会越吃越多，越睡越多，越长越胖，任期生长下去，最后身体各器官会不堪重负，泛起州病理状态以致衰竭�？杉蒲б扯钥到∈呛蔚鹊闹饕�。
【原文摘录】
Nature Neuroscience | Article
Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats
Published online 28 March 2010 Paul M Johnson & Paul J Kenny
We found that development of obesity was coupled with emergence of a progressively worsening deficit in neural reward responses. Similar changes in reward homeostasis induced by cocaine or heroin are considered to be crucial in triggering the transition from casual to compulsive drug-taking. Accordingly, we detected compulsive-like feeding behavior in obese but not lean rats, measured as palatable food consumption that was resistant to disruption by an aversive conditioned stimulus. Striatal dopamine D2 receptors (D2Rs) were downregulated in obese rats, as has been reported in humans addicted to drugs. Moreover, lentivirus-mediated knockdown of striatal D2Rs rapidly accelerated the development of addiction-like reward deficits and the onset of compulsive-like food seeking in rats with extended access to palatable high-fat food. These data demonstrate that overconsumption of palatable food triggers addiction-like neuroadaptive responses in brain reward circuits and drives the development of compulsive eating. Common hedonic mechanisms may therefore underlie obesity and drug addiction.
3. “多巴胺D2受体”研究为治疗“第一晚效应”提供新思绪
【摘要】
医学上把一些人换床后无法入睡的征象称为“第一晚效应”。资料显示，随着工业化历程的加速，社会竞争、事情压力、不良夜生涯习惯及生齿老龄化等缘故原由，全球三分之一的人保存睡眠问题，其中不少人因经常出差不可在习惯的床上睡眠或入睡前情绪改变、精神亢奋或主要而难以入眠，深陷“第一晚效应”的痛苦之中不可自拔，严重影响到越日事情效率和身体康健。复旦大学医学神经生物学国家重点实验室黄志力课题组研究职员曲卫敏副教授、徐昕红博士等运用高度自动化睡眠醒觉剖析系统，纪录已经基因剔除“多巴胺D2受体”小鼠的睡眠历程，并团结药理学等手段，从基因到行为剖析了多巴胺D2受体在睡眠醒觉调控中的作用。效果发明，与正常小鼠（野生型小鼠）相比，剔除了多巴胺D2受体的小鼠，运动期维持醒觉难题，睡眠量增添。 为模拟人在新情形下如出差住宿等，泛起换床后失眠征象，即“第一晚效应”，研究职员替换动物栖身情形，考察小鼠在新情形中的睡眠行为。效果显示，多巴胺D2受体正常的小鼠面临新情形刺激，极为不习惯、入睡难题，而剔除了多巴胺D2受体的小鼠则“高枕无忧”，迅速入睡。
【点评】
多巴胺D2受体删除的老鼠实验中不泛起”第一晚效应”, 在新情形中能迅速入睡，且睡眠量增添。 这个征象是否与生物钟有关，能否在改善睡眠上有使用价值，值得研究一下，看是否可能用在生物钟饮食疗法上。不过需要注重的是，通过基因敲除手艺研究的结论只是单个（或某几个）基因的作用，无法思量或扫除整体的调控在其中的影响，因此结论往往不是那么十分确定的。
【原文摘录】
The Journal of Neuroscience, March 24, 2010, 30(12):4382-4389; doi:10.1523
Essential Role of Dopamine D2 Receptor in the Maintenance of Wakefulness, But Not in Homeostatic Regulation of Sleep, in Mice
Wei-Min Qu,1 Xin-Hong Xu,1 Ming-Ming Yan,1 Yi-Qun Wang,1 Yoshihiro Urade,2 and Zhi-Li Huang1
Dopamine (DA) and its D2 receptor (R) are involved in cognition, reward processing, and drug addiction. However, their roles in sleep–wake regulation remain unclear. Herein we investigated the role of D2R in sleep–wake regulation by using D2R knock-out (KO) mice and pharmacological manipulation. Compared with WT mice, D2R KO mice exhibited a significant decrease in wakefulness, with a concomitant increase in non-rapid eye movement (non-REM, NREM) and REM sleep and a drastic decrease in the low-frequency (0.75–2 Hz) electroencephalogram delta power of NREM sleep, especially during the first 4 h after lights off. The KO mice had decreased mean episode duration and increased episode numbers of wake and NREM sleep, many stage transitions between wakefulness and NREM sleep during the dark period, suggesting the instability of the wake stage in these D2R KO mice. When the KO mice were subjected to a cage change or an intraperitoneal saline injection, the latency to sleep in the KO mice decreased to half of the level for WT mice. The D2R antagonist raclopride mimicked these effects in WT mice. When GBR12909, a dopamine transport inhibitor, was administered intraperitoneally, it induced wakefulness in WT mice in a dose-dependent manner, but its arousal effect was attenuated to one-third in the D2R KO mice. However, these 2 genotypes showed an identical response in terms of sleep rebound after 2, 4, and 6 h of sleep deprivation. These results indicate that D2R plays an essential role in the maintenance of wakefulness, but not in homeostatic regulation of NREM sleep.
4. 番茄基因加抗艾滋药物的新基因疗法治疗癌症
【摘要】
瑞典研究职员最新发明，一种番茄基因与药物组合后能破损癌细胞，这一发明将有助于用基因疗法治疗癌症。瑞典隆德大学研究职员日前揭晓公报说，这种番茄基因在资助建设和修复番茄基因组方面“非�；钤尽�，但它自己并缺乏以破损癌细胞。在先后测试了差别药物后，研究职员最终发明，这种番茄基因与抗艾滋病药物AZT组合后，能更有用地攻击癌细胞。研究职员指出，许多人对基因疗法心存疑虑，担心病人的基因在接受治疗后爆发改变，引发更多的不良反应。然而，上述研究并不保存这种危害 ，由于番茄基因仅仅被注入癌细胞内，并不影响其他细胞。 新华网 2010-3-29 12:11:30
【点评】
细胞作育以及裸鼠实验显示 西红柿TK1基因与抗艾滋药物逆转录酶抑制剂AZT组合的自杀基因疗法团结干细胞介导的基因注入 显著提高了癌细胞对药物的敏感度，实质性的抑制了肿瘤生长，可以说在针对癌细胞的攻击方面这简直是个很好的战略，只是一方面还仅仅在实验动物身上看到效果，另一方面，它并未有显示出可以治愈癌症的潜力，并且将异种基因转入动物体内哪怕只是体内的癌细胞中会爆发什么效果尚未可知，也就保存着未知的危害。最基本的，这种战略依然是治标不治本。
【原文摘录】
Neuro Oncol. 2010 Feb 13 PMID: 20154339
Plant thymidine kinase 1: a novel efficient suicide gene for malignant glioma therapy.
Khan Z, Knecht W, Willer M, Rozpedowska E, Kristoffersen P, Clausen AR, Munch-Petersen B, Almqvist PM, Gojkovic Z, Piskur J, Ekstr?m TJ.
The prognosis for malignant gliomas remains poor, and new treatments are urgently needed. Targeted suicide gene therapy exploits the enzymatic conversion of a prodrug, such as a nucleoside analog, into a cytotoxic compound. Although this therapeutic strategy has been considered a promising regimen for central nervous system (CNS) tumors, several obstacles have been encountered such as inefficient gene transfer to the tumor cells, limited prodrug penetration into the CNS, and inefficient enzymatic activity of the suicide gene. We report here the cloning and successful application of a novel thymidine kinase 1 (TK1) from the tomato plant, with favorable characteristics in vitro and in vivo. This enzyme (toTK1) is highly specific for the nucleoside analog prodrug zidovudine (azidothymidine, AZT), which is known to penetrate the blood-brain barrier. An important feature of toTK1 is that it efficiently phosphorylates its substrate AZT not only to AZT monophosphate, but also to AZT diphosphate, with excellent kinetics. The efficiency of the toTK1/AZT system was confirmed when toTK1-transduced human glioblastoma (GBM) cells displayed a 500-fold increased sensitivity to AZT compared with wild-type cells. In addition, when neural progenitor cells were used as delivery vectors for toTK1 in intracranial GBM xenografts in nude rats, substantial attenuation of tumor growth was achieved in animals exposed to AZT, and survival of the animals was significantly improved compared with controls. The novel toTK1/AZT suicide gene therapy system in combination with stem cell-mediated gene delivery promises new treatment of malignant gliomas.
5. 一种可使药物直接攻击癌细胞的全新要领
【摘要】
加拿大蒙特利尔大学和拉瓦尔大学的科学家发明了一种可使药物直接攻击癌细胞的全新要领，其可为急性骨髓白血病患者等癌症病人带来福音。据科学家称，这种新要领现在已靠近于临床试验。相关文章揭晓在最新出书的《生物化学杂志》上。 研究认真人、蒙特利尔大学药学系教授丁戴尔•拉门塔尔体现，他们发明人体中部分类型的细胞保存一个“门口”，如源自骨髓的细胞就保存一个允许博来霉素等抗癌药物进入的“门”，找到并翻开这扇“门”就可让药物直接攻击引发白血病的癌细胞。该效果为癌症治疗开发了一条新途径。
拉门塔尔教授先容，他在十年前最先将该理论付诸实践，在与人体细胞十分靠近的发酵用酵母上举行了试验。现在所获发明正是基于酵母实验的效果，新要领可被应用于人体细胞，并能很快进入临床治疗。
据先容，新要领关于癌症患者特殊是急性骨髓白血病患者实属福音。急性骨髓白血病影响人的白细胞，这种癌症很是难治疗，绝大部分患者对种种抗癌药物没有反应。拉门塔尔教授体现，新要领可以将抗癌药剂以束流的形式治疗急性骨髓白血病。他说：“例如我们发明博来霉素等抗癌药剂对来自患者身上的淋巴瘤细胞具有正面效果，但同时还要依赖‘门口’的保存。”由于博来霉素不体现为免疫抑制剂，他以为这对患者来说是一个十分利好的新闻。
拉门塔尔教授还提醒到，新找到的“门口”只保存于部分细胞类型，好比那些来自于骨髓的细胞，但关于乳腺癌等就不起作用，这样就很难使用博来霉素等来治疗乳腺癌患者。因此，他以为现在应着手寻找能够刺激“门口”爆发的方法，这样才华够使用博来霉素等药物治疗更多类型的癌症
【点评】
寻找能够刺激“门口”爆发的方法是没准的事情，要寻找只刺激癌细胞“门口”爆发的方法，不影响正常细胞，更难。总之不可解决药物对癌细胞和正常细胞的相似作用，化疗的远景就无法看好。若是能像再生营养物质那样在有利于正常细胞的同时祛除癌细胞，把看似矛盾的两个方面统一起来做到一石二鸟。这才是癌症治疗的最好效果。
【原文摘录】
JBC doi: 10.1074/jbc.M109.046151
The Human Carnitine Transporter SLC22A16 Mediates High Affinity Uptake of the Anticancer Polyamine Analogue Bleomycin-A5*
Mustapha Aouida,1, Richard Poulin§ and Dindial Ramotar,2
Bleomycin is used in combination with other antineoplastic agents to effectively treat lymphomas, testicular carcinomas, and squamous cell carcinomas of the cervix, head, and neck. However, resistance to bleomycin remains a persistent limitation in exploiting the full therapeutic benefit of the drug with other types of cancers. Previously, we documented that the Saccharomyces cerevisiae L-carnitine transporter Agp2 is responsible for the high affinity uptake of polyamines and of the polyamine analogue bleomycin-A5. Herein, we document that the human L-carnitine transporter hCT2 encoded by the SLC22A16 gene is involved in bleomycin-A5 uptake, as well as polyamines. We show that NT2/D1 human testicular cancer cells, which highly express hCT2, are extremely sensitive to bleomycin-A5, whereas HCT116 human colon carcinoma cells devoid of detectable hCT2 expression or MCF-7 human breast cancer cells that only weakly express the permease showed striking resistance to the drug. NT2/D1 cells accumulated fluorescein-labeled bleomycin-A5 to substantially higher levels than HCT116 cells. Moreover, L-carnitine protected NT2/D1 cells from the lethal effects of bleomycin-A5 by preventing its influx, and siRNA targeted to hCT2 induced resistance to bleomycin-A5-dependent genotoxicity. Furthermore, hCT2 overexpression induced by transient transfection of a functional hCT2-GFP fusion protein sensitized HCT116 cells to bleomycin-A5. Collectively, our data strongly suggest that hCT2 can mediate bleomycin-A5 and polyamine uptake, and that the rate of bleomycin-A5 accumulation may account for the differential response to the drug in patients.
6. C60运载基因手艺为糖尿病患者送福音
【摘要】
日本东京大学的研究职员首次开发出了使用超小球形碳分子C60（富勒烯）导入基因的新手艺。该手艺有望为糖尿病患者带来福音。C60是60个碳原子团结在一起形成的直径缺乏1纳米的球状细小粒子。东京大学副教授野入英世和教授中村荣一率领的研究小组让C60携带4个氨基，制造出了水溶性C60，使其与基因团结成为可能。
研究职员将团结了绿色荧光卵白基因的水溶性C60注射到实验鼠体内。效果发明实验鼠的肺、肝和脾都泛起了该基因，证实了水溶性C60具有强盛的基因运载能力 。在随后的实验中，研究职员让水溶性C60携带指导合成胰岛素的基因进入实验鼠体内，效果实验鼠体内的胰岛素水平增添到寻常的1.5倍，血糖值也降低了20%以上。研究职员先容说，与基因团结的水溶性C60穿详尽胞膜以后就会与基因疏散，随尿液倾轧体外，不会在体内群集。
现在，治疗糖尿病的手段主要是通过给患者直接注射胰岛向来降低血糖值。日本研究职员以为，此次开发的新手艺抵达适用化水平后，降低血糖值效果的一连时间将比直接注射还要长，由此将大大减轻患者的肩负。另外，这项新手艺尚有可能促成清静性更高的基因治疗糖尿病要领的泛起。
【点评】
该手艺若能生长成熟，可能会为RNAi手艺更好的用于需基因治疗的疾病提供很大资助。总之，这看上去是一项很好的基因运载手艺。
【原文摘录】
PNAS doi: 10.1073/pnas.0909223107
In vivo gene delivery by cationic tetraamino fullerene
Rui Maeda-Mamiyaa,b, Eisei Noirib,1, Hiroyuki Isobec, Waka Nakanishic, Koji Okamotob, Kent Doib, Takeshi Sugayad, Tetsuro Izumie, Tatsuya Hommaa, and Eiichi Nakamuraa,1
Application of nanotechnology to medical biology has brought remarkable success. Water-soluble fullerenes are molecules with great potential for biological use because they can endow unique characteristics of amphipathic property and form a self-assembled structure by chemical modification. Effective gene delivery in vitro with tetra(piperazino)fullerene epoxide (TPFE) and its superiority to Lipofectin have been described in a previous report. For this study, we evaluated the efficacy of in vivo gene delivery by TPFE. Delivery of enhanced green fluorescent protein gene (EGFP) by TPFE on pregnant female ICR mice showed distinct organ selectivity compared with Lipofectin; moreover, higher gene expression by TPFE was found in liver and spleen, but not in the lung. No acute toxicity of TPFE was found for the liver and kidney, although Lipofectin significantly increased liver enzymes and blood urea nitrogen. In fetal tissues, neither TPFE nor Lipofectin induced EGFP gene expression. Delivery of insulin 2 gene to female C57/BL6 mice increased plasma insulin levels and reduced blood glucose concentrations, indicating the potential of TPFE-based gene delivery for clinical application. In conclusion, this study demonstrated effective gene delivery in vivo for the first time using a water-soluble fullerene.
7. 基因疗法恢复患眼疾小鼠视力
【摘要】
据外洋媒体报道，来自美国纽约州布法罗市、俄亥俄州克利夫兰市和俄克拉何马州的科学家使用基因疗法，改善具有视网膜色素变性疾病的老鼠视力。这一研究效果批注，科学家在使瞽者恢复视力的蹊径上取得了长足的前进。据悉，《美国实验生物学学会团结会杂志》2010年4月刊上揭晓的一篇研究报告中，科学家详细叙述了使用合成的纳米颗粒，改善具有视网膜色素变性疾病老鼠视力的历程。视网膜色素变性是视网膜光感受器细胞和色素上皮细胞变性，从而导致夜盲和举行性视野缺损的一组具有临床亚型的基因遗传性致瞎眼病。
研究小组成员，俄克拉何马州奥克拉荷马大学康健科学中心细胞生物学系莱西博士和她的同事一起，研究了一组带有视网膜缓慢变性基因的老鼠。莱西和她的同事对这些老鼠举行了三种差别类型的治疗要领：一种要领是用包括Rds基因的纳米颗粒来治疗，一种要领是用正�；蚶粗瘟�，尚有一种要领是通过心理盐水来治疗。 实验三种差别类型的治疗要领后，研究职员将实验老鼠和其它具有视网膜色素变性或视网膜缓慢变性疾病老鼠举行较量，从而剖析得出实验老鼠视网膜的功效和结构。研究职员发明，接受纳米颗�；蛄品ǖ睦鲜�，其视觉功效获得改善，具有显着愈合的迹象，并且这种效果到实验竣事都还坚持完好，而接受正�；蚝托睦硌嗡瘟频睦鲜�，其视力一直下降。上述实验效果批注，纳米颗粒是耐受性优异，并且是清静无副作用的治疗要领。
研究职员称，他们希望此研究效果可资助治愈那些和视网膜色素变性、遗传性疾病和后天视网膜疾病等导致失明的疾病。 《美国实验生物学学会团结会杂志》杂志主编，杰拉尔• 德韦斯曼说：“使瞽者恢复视力一经被称为事业。随着我们对进化、遗传学和纳米手艺明确的加深，这种神奇的治疗要领将变得很是普遍。”
【点评】
瞽者复明是圣经中的神迹，是医学上的难题，上述基因疗法还只是在老鼠实验中显示了效力，不过也能给瞽者患者带来一丝期望，是基因治疗的前进之一，虽然基因疗法在临床应用上还很不可熟，也不确定究竟能否成熟起来，事实这是在干预人体自身的遗传信息，会造成多大的影响，什么样的影响，我们并不清晰。
【原文摘录】
Published as doi: 10.1096/fj.09-139147. (The FASEB Journal. 2010;24:1178-1191.)
Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa
Xue Cai*, Shannon M. Conley*, Zack Nash*, Steven J. Fliesler , , , Mark J. Cooper|| and Muna I. Naash*,1
The purpose of the present study was to test the therapeutic efficiency and safety of compacted-DNA nanoparticle-mediated gene delivery into the subretinal space of a juvenile mouse model of retinitis pigmentosa. Nanoparticles containing the mouse opsin promoter and wild-type mouse Rds gene were injected subretinally into mice carrying a haploinsufficiency mutation in the retinal degeneration slow (rds+/–) gene at postnatal day (P)5 and 22. Control mice were either injected with saline, injected with uncompacted naked plasmid DNA carrying the Rds gene, or remained untreated. Rds mRNA levels peaked at postinjection day 2 to 7 (PI-2 to PI-7) for P5 injections, stabilized at levels 2-fold higher than in uninjected controls for both P5 and P22 injections, and remained elevated at the latest time point examined (PI-120). Rod function (measured by electroretinography) showed modest but statistically significant improvement compared with controls after both P5 and P22 injections. Cone function in nanoparticle-injected eyes reached wild-type levels for both ages of injections, indicating full prevention of cone degeneration. Ultrastructural examination at PI-120 revealed significant improvement in outer segment structures in P5 nanoparticle-injected eyes, while P22 injection had a modest structural improvement. There was no evidence of macrophage activation or induction of IL-6 or TNF- mRNA in P5 or P22 nanoparticle-dosed eyes at either PI-2 or PI-30. Thus, compacted-DNA nanoparticles can efficiently and safely drive gene expression in both mitotic and postmitotic photoreceptors and retard degeneration in this model. These findings, using a clinically relevant treatment paradigm, illustrate the potential for application of nanoparticle-based gene replacement therapy for treatment of human retinal degenerations.—Cai, X., Conley, S. M., Nash, Z., Fliesler, S. J., Cooper, M. J., Naash, M. I. Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa.
8. DAF-16基因同寿命亲近相关
【摘要】
从遗传学角度研究朽迈机制的一组英国科学家4月1日在《公共科学图书馆•综合》网站撰文指出，他们针对实验室蠕虫举行的研究批注，DAF-16基因同寿命、免疫力亲近相关。由于许多动物和人体内都拥有DAF-16基因，该发明有助于更好地相识影响人类朽迈和免疫功效的缘故原由。全球各地的人们正在大踏步迈向朽迈，给康健和社会包管系统提出了重大挑战。丹麦科学家去年举行的一项研究发明，富足国家出生的婴儿中，有一半将可以庆祝其百岁诞辰�？蒲Ъ壹鼻信卧改芄徽业搅钊诵嗦醯脑倒试�，据此研发出药物资助人们尽可能长寿，并在有生之年坚持康健。英国伯明翰大学的罗宾•梅尔向导了这项研究。梅尔团队较量了4种关系亲近的蠕虫的寿命、抗药性以及免疫力情形，他们发明，这4种蠕虫体内的DAF-16基因的活性保存重大的差别。更主要的是，DAF-16活性的差别同寿命、对抗力和免疫力相辅相成：DAF-16的活性越高，蠕虫的寿命越长，抗熏染的免疫力越好。梅尔体现，这批注，免疫力和朽迈亲近相关。物种之间的DAF-16基因的活性的差别对朽迈和康健具有很是主要的影响，这或允许以诠释人与人之间的寿命为何差别。
梅尔称，DAF-16在体内大大都细胞中都很活跃，它们同人体内的FoxO家族调理基因很是类似，科学家以为FOXO家族在动物细胞的分解、生长、增殖、代谢、免疫及朽迈调理方面具有多样性功效。英国生物手艺和生物科学研究协会认真人性格拉斯•凯尔体现，这个发明将资助科学家明确决议人类朽迈的相关机制。
【点评】
在分子机制上研究朽迈和免疫，期望能够找到令人朽迈的缘故原由，据此研发出药物资助人们尽可能长寿，并在有生之年坚持康健。在重大的分子调控网络条理是做这项研究，纵然有希望，也尚有很漫长的路要走。而在细胞水平上的研究，人体再生回复科学则已经找到了预防朽迈的途径并正在用于人体养生。
【原文摘录】
Phenotypic Covariance of Longevity, Immunity and Stress Resistance in the Caenorhabditis Nematodes
Francis R. G. Amrit, Claudia M. L. Boehnisch, Robin C. May*
Abstract
Background
Ageing, immunity and stresstolerance are inherent characteristics of all organisms. In animals, these traits are regulated, at least in part, by forkhead transcription factors in response to upstream signals from the Insulin/Insulin–like growth factor signalling (IIS) pathway. In the nematode Caenorhabditis elegans, these phenotypes are molecularly linked such that activation of the forkhead transcription factor DAF-16 both extends lifespan and simultaneously increases immunity and stress resistance. It is known that lifespan varies significantly among the Caenorhabditis species but, although DAF-16 signalling is highly conserved, it is unclear whether this phenotypic linkage occurs in other species. Here we investigate this phenotypic covariance by comparing longevity, stress resistance and immunity in four Caenorhabditis species.
Methodology/Principal Findings
We show using phenotypic analysis of DAF-16 influenced phenotypes that among four closely related Caenorhabditis nematodes, the gonochoristic species (Caenorhabditis remanei and Caenorhabditis brenneri) have diverged significantly with a longer lifespan, improved stress resistance and higher immunity than the hermaphroditic species (C. elegans and Caenorhabditis briggsae). Interestingly, we also observe significant differences in expression levels between the daf-16 homologues in these species using Real-Time PCR, which positively correlate with the observed phenotypes. Finally, we provide additional evidence in support of a role for DAF-16 in regulating phenotypic coupling by using a combination of wildtype isolates, constitutively active daf-16 mutants and bioinformatic analysis.
Conclusions
The gonochoristic species display a significantly longer lifespan (p<0.0001) and more robust immune and stress response (p<0.0001, thermal stress; p<0.01, heavy metal stress; p<0.0001, pathogenic stress) than the hermaphroditic species. Our data suggests that divergence in DAF-16 mediated phenotypes may underlie many of the differences observed between these four species of Caenorhabditis nematodes. These findings are further supported by the correlative higher daf-16 expression levels among the gonochoristic species and significantly higher lifespan, immunity and stress tolerance in the constitutively active daf-16 hermaphroditic mutants。