CQS receives a fellowship from the LOEWE Excellence Cluster for Integrative Fungal Research (IPF). The author would like to thank Ida J. van der Klei for the P. chrysogenum strains used in this work and Andreas S. Reichert for the gift of rapamycin.

1.准备P.的黄青霉的饥饿实验<ol><li>如果P.感兴趣的产黄青霉株保持对水稻（"绿色大米"），将布满菌丝孢子到1.5 ml离心管2-3米粒。它用500μlYGG（10克/升氯化钾20克/升葡萄糖，10g / l酵母氮碱，5克/升K 2 HPO 4 20克/升酵母提取物）填充。 <ol><li>涡管30秒，使孢子可从水稻分离效率。 </li><li>孵育管中1天，在室温（ 例如 ，20至25℃）。 </li><li>准备一个1/50稀释这种孢子悬浮液中无菌自来水，搅拌均匀。 </li></ol></li><li>如果P.感兴趣chrysogenum菌株被保持在琼脂平板上（ 例如 ，YGG琼脂板），转移小块菌丝到含有400微升无菌自来水和大约100毫克GL 1.5ml微量离心管屁股珠用无菌牙签或枪头。 <ol><li>涡管2分钟，使菌丝体变得支离破碎。立即使用该管的内容物。 </li></ol></li></ol>为培育P. 2预备步骤黄青霉对饥饿垫<ol><li>接通加热板，并将其设定为约60℃。 </li><li>溶解2克琼脂糖在100毫升由烹调在微波炉中的溶液自来水。请注意，这个解决方案是加热后完全清楚。如果不是，再次煮直到琼脂糖完全溶解。让琼脂糖溶液冷却至约60℃，使用前。 </li><li>填充的1.5 ml离心管（2-4，这取决于样品的数量）用400μl无菌自来水（不添加额外的化合物），每个或400-X微升（除了x的微升在步骤2.5化合物溶液），并把它们到加热板为至少1分钟，以使笏呃内得到温暖。 </li><li>放置显微镜载玻片包含一个中心腔到加热板至少1分钟。 </li><li>琼脂加入400微升2％至1.5 ml离心管和涡简要的解决方案。在此步骤之后，如果需要的话，加入另外的化合物（ 即，1μM的雷帕霉素）。如果这样做，涡旋后短暂每个附加物质被吸向管。放管放回加热表，以防止过早固化。 注:在离心管中的总量应该是800微升。 </li></ol> 3.准备显微镜载玻片的含饥饿垫<ol><li>吸管140微升琼脂糖溶液到显微镜载玻片的腔（其仍位于加热板）。尽量避免，如果可能，气泡。 </li><li>立即将盖玻片上的琼脂糖溶液。 注意:这将导致在一个平面上。 </li><li>把微范围滑动到实验台上大约4分钟，使琼脂糖垫巩固。 </li><li>小心地用拇指或食指的帮助下滑动它关闭删除琼脂糖垫盖玻片（戴手套，以避免污染！）。 </li><li>放置与垫显微镜载玻片成湿腔室，以防止干燥。建议:使用一个空的提示框，仍然有插入举办的枪头。加入无菌水到盒使得底部被覆盖。放置在显微镜载玻片上的插入件并关闭对话框。 </li></ol> 4.接种饥饿垫与P.黄青霉和孵化<ol><li>吸移管将5μl的1/50稀释孢子（如果培养物生长在水稻）或5微升含有片段的菌丝体（如培养物生长在琼脂平板上）上饥饿垫的中心的未稀释溶液组成。 </li><li>关闭湿室，把它包在一个塑料袋（这作为额外的保护，防止饥饿垫干燥）。要小心，不要将箱子太大，否则接种滴会受到干扰。 </li><li>分析样品之前，存储在RT包装的盒子进行至少20小时。 </li></ol>该样品5显微分析<ol><li> 20小时温育后，将样品准备显微镜分析;放在干燥的纸巾显微镜载玻片（底部趋于湿）。 </li><li>吸取小体积的水（约50微升）到饥饿垫。把盖玻片上垫挤掉多余的水分。用纸巾去除多余的水。 </li><li>把载玻片上的荧光显微镜的观察表。为了让菌丝生长的概述，用20倍的目标。使用63X或100X目标研究GFP的本地化的菌丝。为了防止试样的逐渐干燥不分析样品为前长于15分钟把它们放回湿室。 </li><li>重复5.3定期（ 例如 ，40小时和60小时生长后）。 注:样品可以放回湿室中。这是没有必要除去盖玻片，因为它不影响菌丝生长。 </li></ol>

<ol>
	<li>Fischer, F., Hamann, A., Osiewacz, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+quality+control:+an+integrated+network+of+pathways.">Mitochondrial quality control: an integrated network of pathways.</a> Trends Biochem. Sci. 37 (7), 284-292 (2012).</li><li>Pollack, J. K., Harris, S. D., Marten, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagy+in+filamentous+fungi.">Autophagy in filamentous fungi.</a> Fungal Genet. Biol. 46 (1), 1-8 (2009).</li><li>Scheckhuber, C. Q., Osiewacz, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Podospora+anserina:+a+model+organism+to+study+mechanisms+of+healthy+ageing.">Podospora anserina: a model organism to study mechanisms of healthy ageing.</a> Mol. Genet. Genomics. 280 (5), 365-374 (2008).</li><li>Pinan-Lucarr&#233;, B., Iraqui, I., Clav&#233;, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Podospora+anserina+target+of+rapamycin.">Podospora anserina target of rapamycin.</a> Curr. Genet. 50 (1), 23-31 (2006).</li><li>Kikuma, T., Ohneda, M., Arioka, M., Kitamoto, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+analysis+of+the+ATG8+homologue+Aoatg8+and+role+of+autophagy+in+differentiation+and+germination+in+Aspergillus+oryzae.">Functional analysis of the ATG8 homologue Aoatg8 and role of autophagy in differentiation and germination in Aspergillus oryzae.</a> Eukaryot. Cell. 5 (8), 1328-1336 (2006).</li><li>Pinan-Lucarr&#233;, B., Balguerie, A., Clav&#233;, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerated+cell+death+in+Podospora+autophagy+mutants.">Accelerated cell death in Podospora autophagy mutants.</a> Eukaryot. Cell. 4 (11), 1765-1774 (2005).</li><li>Veneault-Fourrey, C., Barooah, M., Egan, M., Wakley, G., Talbot, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagic+fungal+cell+death+is+necessary+for+infection+by+the+rice+blast+fungus.">Autophagic fungal cell death is necessary for infection by the rice blast fungus.</a> Science. 312 (5773), 580-583 (2006).</li><li>Bartoszewska, M., Kiel, J. A., Bovenberg, R. A., Veenhuis, M., van der Klei, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagy+deficiency+promotes+beta-lactam+production+in+Penicillium+chrysogenum.">Autophagy deficiency promotes beta-lactam production in Penicillium chrysogenum.</a> Appl. Environ. Microbiol. 77 (4), 1413-1422 (2011).</li><li>Meijer, W. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peroxisomes+are+required+for+efficient+penicillin+biosynthesis+in+Penicillium+chrysogenum.">Peroxisomes are required for efficient penicillin biosynthesis in Penicillium chrysogenum.</a> Appl. Environ. Microbiol. 76 (17), 5702-5709 (2010).</li><li>Cubitt, A. B., Heim, R., Adams, S. R., Boyd, A. E., Gross, L. A., Tsien, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding,+improving+and+using+green+fluorescent+proteins.">Understanding, improving and using green fluorescent proteins.</a> Trends Biochem. Sci. 20 (11), 448-455 (1995).</li><li>Jung, C. H., Ro, S. H., Cao, J., Otto, N. M., Kim, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=mTOR+regulation+of+autophagy.">mTOR regulation of autophagy.</a> FEBS Lett. 584 (7), 1287-1295 (2010).</li><li>Hickey, P. C., Read, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+living+cells+of+Aspergillus+in+vitro.">Imaging living cells of Aspergillus in vitro.</a> Med. Mycol. 47, S110-S119 (2009).</li></ol>

The author has nothing to disclose.

这里介绍的方法允许自噬在P.方便和可重复的研究黄青霉 。例如，它可用于筛选各种化合物的功效它们是否能够调节这种真菌与否的自噬反应。雷帕霉素的研究结果表明，抑制TOR信令导致明显的诱导自噬在体育黄青霉这也被证明对其他生物体11。 它可以使用在更复杂的显微镜（ 例如 ，共聚焦激光扫描显微镜）上生长饥饿焊盘用于分析菌丝?...

丝状真菌是优秀的模型系统的发育过程的研究。他们提供了几个实验的优惠，如廉价的种植，高数量的后代遗传的可访问性。最后一点是转化的允许调查迄今为止在非特异基因的各种细胞机制的重要建设特别重要的。丝状真菌是有助的几个元件和蜂窝质量控制通路像为异常蛋白，线粒体动力学的降解蛋白酶活性的机制的阐明对维持线粒体的完整性和自噬用于去除过剩和/或不正常的细胞成分和用于维持细胞活力在饥饿1,2,3次。 有可用于自噬在丝状真菌2该研究的几个实验技术:空泡（ⅰ）调查我˚F它们含有致密的自噬体时的蛋白酶是由透射电子显微镜4的抑制作用，（ⅱ）自噬体通过经由荧光显微镜5,6和（iii）检测酸化autophagosomal结 ​​构监测GFP-ATG8灶通过使用荧光染料monodansyl尸胺可视7。 这里，一个新的增长的产黄青霉菌对自噬的研究方法。主要元素是&#39;饥饿垫"，这只是由琼脂糖溶解在无菌自来水中的1％。另外的化合物（ 例如，压力源，清除剂，自噬调制器）可以使用，只要它们不显示自发荧光加至垫。该垫位于显微镜载玻片包含一个浅中心空腔。此衬垫在接种要么用孢子悬浮液，或以小的菌丝体片段。后者是可取的，如果所关注的菌株不能sporulatË有效（ 例如，ΔATG1株8）。将载玻片放置在湿室（这些可以很容易地构造使用空枪头框），以防止样品的干燥和在室温下孵育。P.黄青霉能够生长在这些条件下几天。自噬可以通过显微镜液泡增大其是阳性标志物的真菌自噬被观察到。在这方面的贡献，一个P. chrysogenum菌株（威斯康星54-1255）用于形成是受它的C-末端"SKL笔顺9靶向过氧化物酶体绿色荧光蛋白。因此，可以监测过氧化物酶的降解。它是通过使用适当的定位信号也以标记细胞（ 例如，线粒体）的其他车厢，并分析它们的降解是可行的。虽然从数据P.黄青霉 Ws54-1255（GFP-SKL）在这里介绍，这当然是可能的使用&#39;饥饿垫"的方法也可用于其它丝状真菌（ 例如，粗糙脉孢菌，Sordaria macrospora，曲霉菌属等 ）。

<table><tbody><tr><td>Microscope slides with central cavity</td><td>Carl Roth GmbH, Karlsruhe, Germany</td><td>H884.1</td><td>These can be used multiple times after cleaning.</td></tr><tr><td>Glass beads</td><td>Carl Roth GmbH, Karlsruhe, Germany</td><td>A553.1</td><td>Diameter: 0.25 - 0.50 mm</td></tr></tbody></table>

analysis of autophagy in penicillium chrysogenum by using starvation pads in combination with fluorescence microscopy

The study of cellular quality control systems has emerged as a highly dynamic and relevant field of contemporary research. It has become clear that cells possess several lines of defense against damage to biologically relevant molecules like nucleic acids, lipids and proteins. In addition to organelle dynamics (fusion/fission/motility/inheritance) and tightly controlled protease activity, the degradation of surplus, damaged or compromised organelles by autophagy (cellular &#8216;self-eating&#8217;) has received much attention from the scientific community. The regulation of autophagy is quite complex and depends on genetic and environmental factors, many of which have so far not been elucidated. Here a novel method is presented that allows the convenient study of autophagy in the filamentous fungus Penicillium chrysogenum. It is based on growth of the fungus on so-called &#8216;starvation pads&#8217; for stimulation of autophagy in a reproducible manner. Samples are directly assayed by microscopy and evaluated for autophagy induction / progress. The protocol presented here is not limited for use with P. chrysogenum and can be easily adapted for use in other filamentous fungi.

为了证明在P.上述过氧化物酶降解详细介绍了协议的效用chrysogenum菌株Ws54-1255（GFP-SKL）进行了分析。在这株GFP-SKL通常被导入到过氧化物酶体9。这导致多个球形的外观，当样品通过荧光显微镜进行分析。如果发生自噬，空泡放大。 GFP-SKL成为自噬（pexophagy）并入空泡。由于这一事实，即GFP是通过液泡蛋白酶降解抗性它所标记这些细胞器10。因此这两个参数，观察自噬（p...

Watch this Scientific Journal Video about Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy at JoVE.com

Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy

A convenient and powerful method for studying autophagy in Penicillium chrysogenum by using starvation pads (mixtures of agarose and tap water in a microscope slide containing a central cavity) is presented here.

自噬的分析<em&gt;产黄青霉</em&gt;通过结合使用饥饿垫荧光显微镜

The study of cellular quality control systems has emerged as a highly dynamic and relevant field of contemporary research. It has become clear that cells ...

analysis-autophagy-penicillium-chrysogenum-using-starvation-pads

Research

JoVE Journal

Biology

Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy

8.5K 次观看.  Senckenberg Research Institute. A convenient and powerful method for studying autophagy in Penicillium chrysogenum by using starvation pads (mixtures of agarose and tap water in a microscope slide containing a central cavity) is presented here.

视频: Analysis of Autophagy in Penicillium chrysogenum by Using Starvation Pads in Combination With Fluorescence Microscopy

Cecal Ligation and Puncture-induced Sepsis as a Model To Study Autophagy in Mice

Experimental sepsis can be induced in mice using the cecal ligation and puncture (CLP) method, which causes polymicrobial sepsis. Here, a protocol is provided to induce sepsis of varying severity in mice using the CLP technique. Autophagy is a fundamental tissue response to stress and pathogen invasion. Two current protocols to assess autophagy in vivo in the context of experimental sepsis are also presented here. (I) Transgenic mice expressing green fluorescence protein (GFP)-LC3 fusion protein are subjected to CLP. Localized enhancement of GFP signal (puncta), as assayed either by immunohistochemical or confocal assays, can be used to detect enhanced autophagosome formation and, thus, altered activation of the autophagy pathway. (II) Enhanced autophagic vacuole (autophagosome) formation per unit tissue area (as a marker of autophagy stimulation) can be quantified using electron microscopy. The study of autophagic responses to sepsis is a critical component of understanding the mechanisms by which tissues respond to infection. Research findings in this area may ultimately contribute towards understanding the pathogenesis of sepsis, which represents a major problem in critical care medicine.

Experimental sepsis can be induced in mice using the cecal ligation and puncture (CLP) method. Current protocols to assess autophagy in vivo in the context of CLP-induced sepsis are presented here: A protocol for measuring autophagy using (GFP)-LC3 mice, and a protocol for measuring autophagosome formation by electron microscopy.

盲肠结扎穿孔致脓毒症作为模型小鼠中自噬研究

Experimental sepsis can be induced in mice using the cecal ligation and puncture (CLP) method, which causes polymicrobial sepsis. Here, a protocol is ...

科研

免疫与感染

A Fluorescence Microscopy Assay for Monitoring Mitophagy in the Yeast Saccharomyces cerevisiae

Autophagy is important for turnover of cellular components under a range of different conditions. It serves an essential homeostatic function as well as a quality control mechanism that can target and selectively degrade cellular material including organelles1-4. For example, damaged or redundant mitochondria (Fig. 1), not disposed of by autophagy, can represent a threat to cellular homeostasis and cell survival. In the yeast, Saccharomyces cerevisiae, nutrient deprivation (e.g., nitrogen starvation) or damage can promote selective turnover of mitochondria by autophagy in a process termed mitophagy 5-9.
We describe a simple fluorescence microscopy approach to assess autophagy. For clarity we restrict our description here to show how the approach can be used to monitor mitophagy in yeast cells. The assay makes use of a fluorescent reporter, Rosella, which is a dual-emission biosensor comprising a relatively pH-stable red fluorescent protein linked to a pH-sensitive green fluorescent protein. The operation of this reporter relies on differences in pH between the vacuole (pH ~ 5.0-5.5) and mitochondria (pH ~ 8.2) in living cells. Under growing conditions, wild type cells exhibit both red and green fluorescence distributed in a manner characteristic of the mitochondria. Fluorescence emission is not associated with the vacuole. When subjected to nitrogen starvation, a condition which induces mitophagy, in addition to red and green fluorescence labeling the mitochondria, cells exhibit the accumulation of red, but not green fluorescence, in the acidic vacuolar lumen representing the delivery of mitochondria to the vacuole. Scoring cells with red, but not green fluorescent vacuoles can be used as a measure of mitophagic activity in cells5,10-12.

A Fluorescence Microscopy Assay for Monitoring Mitophagy in the Yeast Saccharomyces cerevisiae

A robust approach to monitor the delivery of organelles to the acidic lumen of the yeast vacuole for degradation and recycling is described. The method relies on the specific labeling of target organelles with a genetically encoded dual-emission fluorescence pH-biosensor, and visualization of individual cells using fluorescence microscopy.

在酵母用于监测Mitophagy荧光显微镜检测酿酒酵母

Autophagy is important for turnover of cellular components under a range of different conditions. It serves an essential homeostatic function as well as a ...

生物学

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal dysfunction and loss. Fluorescence-based imaging tools and technologies enable unprecedented analysis of subcellular neurobiological processes, yet there is still a need for unbiased, reproducible, and accessible approaches for extracting quantifiable data from imaging studies. We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-based imaging studies using Drosophila models of neurodegeneration. Specifically, we describe an easy-to-follow, semi-automated approach using Fiji/ImageJ to analyze two cellular processes: first, we quantify protein aggregate content and profile in the Drosophila optic lobe using fluorescent-tagged mutant huntingtin proteins; and second, we assess autophagy-lysosome flux in the Drosophila visual system with ratiometric-based quantification of a tandem fluorescent reporter of autophagy. Importantly, the protocol outlined here includes a semi-automated segmentation step to ensure all fluorescent structures are analyzed to minimize selection bias and to increase resolution of subtle comparisons. This approach can be extended for the analysis of other cell biological structures and processes implicated in neurodegeneration, such as proteinaceous puncta (stress granules and synaptic complexes), as well as membrane-bound compartments (mitochondria and membrane trafficking vesicles). This method provides a standardized, yet adaptable reference point for image analysis and quantification, and could facilitate reliability and reproducibility across the field, and ultimately enhance mechanistic understanding of neurodegeneration.

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-imaging-based cell biological studies of protein aggregation and autophagic flux in the central nervous system of Drosophila models of neurodegeneration.

荧光标记蛋白 ImageJ 的无偏分析在果蝇变性定量细胞生物学中的应用

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal ...

神经科学

Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy

Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, traditional chemotherapeutic approaches have been largely unsuccessful. Hormone therapy is effective at early stage, but often fails with the eventual development of hormone-refractory tumors. We have been interested in developing therapeutics targeting specific metabolic deficiency of tumor cells. We recently showed that prostate tumor cells specifically lack an enzyme (argininosuccinate synthase, or ASS) involved in the synthesis of the amino acid arginine1. This condition causes the tumor cells to become dependent on exogenous arginine, and they undergo metabolic stress when free arginine is depleted by arginine deiminase (ADI)1,10. Indeed, we have shown that human prostate cancer cells CWR22Rv1 are effectively killed by ADI with caspase-independent apoptosis and aggressive autophagy (or macroautophagy)1,2,3. Autophagy is an evolutionarily-conserved process that allows cells to metabolize unwanted proteins by lysosomal breakdown during nutritional starvation4,5. Although the essential components of this pathway are well-characterized6,7,8,9, many aspects of the molecular mechanism are still unclear - in particular, what is the role of autophagy in the death-response of prostate cancer cells after ADI treatment? In order to address this question, we required an experimental method to measure the level and extent of autophagic response in cells - and since there are no known molecular markers that can accurately track this process, we chose to develop an imaging-based approach, using quantitative 3D fluorescence microscopy11,12.
Using CWR22Rv1 cells specifically-labeled with fluorescent probes for autophagosomes and lysosomes, we show that 3D image stacks acquired with either widefield deconvolution microscopy (and later, with super-resolution, structured-illumination microscopy) can clearly capture the early stages of autophagy induction. With commercially available digital image analysis applications, we can readily obtain statistical information about autophagosome and lysosome number, size, distribution, and degree of colocalization from any imaged cell. This information allows us to precisely track the progress of autophagy in living cells and enables our continued investigation into the role of autophagy in cancer chemotherapy.

Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.

采用先进的3D荧光显微镜定量分析自噬

Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, ...

Live Cell Imaging of Early Autophagy Events: Omegasomes and Beyond

Autophagy is a cellular response triggered by the lack of nutrients, especially the absence of amino acids. Autophagy is defined by the formation of double membrane structures, called autophagosomes, that sequester cytoplasm, long-lived proteins and protein aggregates, defective organelles, and even viruses or bacteria. Autophagosomes eventually fuse with lysosomes leading to bulk degradation of their content, with the produced nutrients being recycled back to the cytoplasm. Therefore, autophagy is crucial for cell homeostasis, and dysregulation of autophagy can lead to disease, most notably neurodegeneration, ageing and cancer.	
	Autophagosome formation is a very elaborate process, for which cells have allocated a specific group of proteins, called the core autophagy machinery. The core autophagy machinery is functionally complemented by additional proteins involved in diverse cellular processes, e.g. in membrane trafficking, in mitochondrial and lysosomal biology. Coordination of these proteins for the formation and degradation of autophagosomes constitutes the highly dynamic and sophisticated response of autophagy. Live cell imaging allows one to follow the molecular contribution of each autophagy-related protein down to the level of a single autophagosome formation event and in real time, therefore this technique offers a high temporal and spatial resolution.	
	Here we use a cell line stably expressing GFP-DFCP1, to establish a spatial and temporal context for our analysis. DFCP1 marks omegasomes, which are precursor structures leading to autophagosomes formation. A protein of interest (POI) can be marked with either a red or cyan fluorescent tag. Different organelles, like the ER, mitochondria and lysosomes, are all involved in different steps of autophagosome formation, and can be marked using a specific tracker dye. Time-lapse microscopy of autophagy in this experimental set up, allows information to be extracted about the fourth dimension, i.e. time. Hence we can follow the contribution of the POI to autophagy in space and time.

Time-lapse microscopy of fluorescently labeled autophagy markers allows monitoring of the dynamic autophagy response with high temporal resolution. Using specific autophagy and organelle markers in a combination of 3 different colors, we can follow the contribution of a protein to autophagosome formation in a robust spatial and temporal context.

活细胞成像早期自噬活动:Omegasomes与超越

Autophagy is a  cellular response triggered by the lack of nutrients, especially the absence of  amino acids. Autophagy is defined by the formation of ...

Assessing Autophagic Flux by Measuring LC3, p62, and LAMP1 Co-localization Using Multispectral Imaging Flow Cytometry

Autophagy is a catabolic pathway in which normal or dysfunctional cellular components that accumulate during growth and differentiation are degraded via the lysosome and are recycled. During autophagy, cytoplasmic LC3 protein is lipidated and recruited to the autophagosomal membranes. The autophagosome then fuses with the lysosome to form the autolysosome, where the breakdown of the autophagosome vesicle and its contents occurs. The ubiquitin-associated protein p62, which binds to LC3, is also used to monitor autophagic flux. Cells undergoing autophagy should demonstrate the co-localization of p62, LC3, and lysosomal markers. Immunofluorescence microscopy has been used to visually identify LC3 puncta, p62, and/or lysosomes on a per-cell basis. However, an objective and statistically rigorous assessment can be difficult to obtain. To overcome these problems, multispectral imaging flow cytometry was used along with an analytical feature that compares the bright detail images from three autophagy markers (LC3, p62 and lysosomal LAMP1) and quantifies their co-localization, in combination with LC3 spot counting to measure autophagy in an objective, quantitative, and statistically robust manner.

Here, multispectral imaging flow cytometry with an analytical feature that compares bright detail images of 3 autophagy markers and quantifies their co-localization, along with LC3 spot counting, was used to measure autophagy in an objective, quantitative, and statistically robust manner.

通过使用多光谱成像流式细胞术测量LC3，p62和LAMP1共定位评估自噬通量

Autophagy is a catabolic pathway in which normal or dysfunctional cellular components that accumulate during growth and differentiation are degraded via ...

Study of Protein-protein Interactions in Autophagy Research

Protein-protein interactions are important for understanding cellular signaling cascades and identifying novel pathway components and protein dynamics. The majority of cellular activities require physical interactions between proteins. To analyze and map these interactions, various experimental techniques as well as bioinformatics tools were developed. Autophagy is a cellular recycling mechanism that allows the cells to cope with different stressors, including nutrient deprivation, chemicals, and hypoxia. In order to better understand autophagy-related signaling events and to discover novel factors that regulate protein complexes in autophagy, we performed protein-protein interaction screens. Validation of these screening results requires the use of immunofluorescence and immunoprecipitation techniques. In this system, specific autophagy-related protein-protein interactions that we discovered were tested in Neuro2A (N2A) and HEK293T cell lines. Details of the technical procedures used are explained in this visualized experiment paper.

Presented here are two antibody-based protein-protein interaction research techniques: immunofluorescence and immunoprecipitation. These techniques are suitable for studying physical interactions between proteins for the discovery of novel components of cellular signaling pathways and for understanding protein dynamics.

自噬研究中蛋白质-蛋白质相互作用的研究

Protein-protein interactions are important for understanding cellular signaling cascades and identifying novel pathway components and protein dynamics. ...

Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy

Live-cell imaging is a microscopy technique used to examine cell and protein dynamics in living cells. This imaging method is not toxic, generally does not interfere with cell physiology, and requires minimal experimental handling. The low levels of technical interference enable researchers to study cells across multiple cycles of mitosis and to observe meiosis from beginning to end. Using fluorescent tags such as Green Fluorescent Protein (GFP) and Red Fluorescent Protein (RFP), researchers can analyze different factors whose functions are important for processes like transcription, DNA replication, cohesion, and segregation. Coupled with data analysis using Fiji (a free, optimized ImageJ version), live-cell imaging offers various ways of assessing protein movement, localization, stability, and timing, as well as nuclear dynamics and chromosome segregation. However, as is the case with other microscopy methods, live-cell imaging is limited by the intrinsic properties of light, which put a limit to the resolution power at high magnifications, and is also sensitive to photobleaching or phototoxicity at high wavelength frequencies. However, with some care, investigators can bypass these physical limitations by carefully choosing the right conditions, strains, and fluorescent markers to allow for the appropriate visualization of mitotic and meiotic events.

Here, we present live-cell imaging which is a non-toxic microscopy method that allows researchers to study protein behavior and nuclear dynamics in living fission yeast cells during mitosis and meiosis.

荧光活细胞显微镜对微孔裂变酵母核动力学的检测

Live-cell imaging is a microscopy technique used to examine cell and protein dynamics in living cells. This imaging method is not toxic, generally does ...

Application of Membrane and Cell Wall Selective Fluorescent Dyes for Live-Cell Imaging of Filamentous Fungi

The application of membrane and cell wall selective fluorescent dyes for live-cell imaging analyses of organelle dynamics in fungal cells started two decades ago and since then continues to contribute greatly to our understanding of the filamentous fungal lifestyle. This paper provides a practical guide for the utilization of the two membrane dyes FM 1-43 and FM 4-64 and the four cell wall stains Calcofluor White M2R, Solophenyl Flavine 7GFE 500, Pontamine Fast Scarlet 48 and Congo Red. The focus is on their low-dose application to ascertain artefact-free staining, their co-imaging properties, and their quantitative evaluation. The presented methods are applicable to all filamentous fungal samples that can be prepared in the described ways. The fundamental staining approaches can serve as starting points for adaptations to species that might require different cultivation conditions. First, biophysical and biochemical properties are reviewed as their understanding is essential for using these dyes as truly vital fluorescent stains. Secondly, step-by-step protocols are presented that detail the preparation of various fungal sample types for fluorescent live-cell imaging. Finally, example experiments illustrate different approaches to: (1) identify defects in the spatio-temporal organization of endocytosis in genetic mutants, (2) comparatively characterize shared and distinct co-localization of GFP-labeled target proteins in the endocytic pathway, (3) identify morphogenetic cell wall defects in a genetic mutant, and (4) monitor cell wall biogenesis in real time.

Vital fluorescent dyes are essential tools for live-cell imaging analyses in modern fungal cell biology. This paper details the application of established and lesser-known fluorescent dyes for tracking plasma membrane dynamics, endo-/exocytosis and cell wall morphogenesis in filamentous fungi.

膜和细胞壁选择性荧光染料在丝状真菌活细胞成像中的应用

The application of membrane and cell wall selective fluorescent dyes for live-cell imaging analyses of organelle dynamics in fungal cells started two ...

Analyzing Starvation-Induced Autophagy in the Drosophila melanogaster Larval Fat Body

Autophagy is a cellular self-digestion process. It delivers cargo to the lysosomes for degradation in response to various stresses, including starvation. The malfunction of autophagy is associated with aging and multiple human diseases. The autophagy machinery is highly conserved-from yeast to humans.&#160;The larval fat body of Drosophila melanogaster, an analog for vertebrate liver and adipose tissue, provides a unique model for monitoring autophagy in vivo. Autophagy can be easily induced by nutrient starvation in the larval fat body. Most autophagy-related genes are conserved in Drosophila. Many transgenic fly strains expressing tagged autophagy markers have been developed, which facilitates the monitoring of different steps in the autophagy process. The clonal analysis enables a close comparison of autophagy markers in cells with different genotypes in the same piece of tissue. The current protocol details procedures for (1) generating somatic clones in the larval fat body, (2) inducing autophagy via amino acid starvation, and (3) dissecting the larval fat body, aiming to create a model for analyzing differences in autophagy using an autophagosome marker (GFP-Atg8a) and clonal analysis.

Analyzing Starvation-Induced Autophagy in the Drosophila melanogaster Larval Fat Body

The present protocol describes the induction of autophagy in the Drosophila melanogaster larval fat body via nutrient depletion and analyzes changes in autophagy using transgenic fly strains.

分析黑 腹果蝇 幼虫脂肪体中饥饿诱导的自噬

Autophagy is a cellular self-digestion process. It delivers cargo to the lysosomes for degradation in response to various stresses, including starvation. ...

自噬的分析

摘要

探索更多视频

此视频中的章节

盲肠结扎穿孔致脓毒症作为模型小鼠中自噬研究

在酵母用于监测Mitophagy荧光显微镜检测酿酒酵母

荧光标记蛋白 ImageJ 的无偏分析在果蝇变性定量细胞生物学中的应用

采用先进的3D荧光显微镜定量分析自噬

活细胞成像早期自噬活动:Omegasomes与超越

通过使用多光谱成像流式细胞术测量LC3，p62和LAMP1共定位评估自噬通量

自噬研究中蛋白质-蛋白质相互作用的研究

荧光活细胞显微镜对微孔裂变酵母核动力学的检测

膜和细胞壁选择性荧光染料在丝状真菌活细胞成像中的应用

分析黑腹果蝇幼虫脂肪体中饥饿诱导的自噬

自噬的分析

摘要

探索更多视频

此视频中的章节

盲肠结扎穿孔致脓毒症作为模型小鼠中自噬研究

在酵母用于监测Mitophagy荧光显微镜检测酿酒酵母

荧光标记蛋白 ImageJ 的无偏分析在果蝇变性定量细胞生物学中的应用

采用先进的3D荧光显微镜定量分析自噬

活细胞成像早期自噬活动:Omegasomes与超越

通过使用多光谱成像流式细胞术测量LC3，p62和LAMP1共定位评估自噬通量

自噬研究中蛋白质-蛋白质相互作用的研究

荧光活细胞显微镜对微孔裂变酵母核动力学的检测

膜和细胞壁选择性荧光染料在丝状真菌活细胞成像中的应用

分析黑 腹果蝇 幼虫脂肪体中饥饿诱导的自噬

分析黑腹果蝇幼虫脂肪体中饥饿诱导的自噬