<meta charset="utf8"></head><body>通过用户需求分析创新一种改进的细胞刮刀，用于细胞损伤

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>CCK-8 Kit</td>
			<td>Beyotime Company, China</td>
			<td>C0037</td>
			<td></td>
		</tr>
		<tr>
			<td>digital microscope system</td>
			<td>Olympus</td>
			<td>IX81</td>
			<td></td>
		</tr>
		<tr>
			<td>fetal bovine serum</td>
			<td>Gibco, USA</td>
			<td>16000044</td>
			<td></td>
		</tr>
		<tr>
			<td>HOS&#160;</td>
			<td>Procell Life Science &#38; Technology Co., Ltd</td>
			<td>CL-0360</td>
			<td></td>
		</tr>
		<tr>
			<td>Image-Pro Plus</td>
			<td>Media Cybernetics</td>
			<td>version 6.0</td>
			<td></td>
		</tr>
		<tr>
			<td>KeyShot</td>
			<td>Luxion</td>
			<td>version 11.0</td>
			<td>3D rendering software</td>
		</tr>
		<tr>
			<td>microplate reader</td>
			<td>BioTek, German</td>
			<td>ELX808</td>
			<td></td>
		</tr>
		<tr>
			<td>Minimum Essential Medium</td>
			<td>Gibco, USA</td>
			<td>11095080</td>
			<td></td>
		</tr>
		<tr>
			<td>Pantone matching system</td>
			<td>Pantone</td>
			<td></td>
			<td>commercial color matching</td>
		</tr>
		<tr>
			<td>penicillin-streptomycin</td>
			<td>Beyotime Company, China</td>
			<td>ST488</td>
			<td></td>
		</tr>
		<tr>
			<td>Photoshop</td>
			<td>Adobe</td>
			<td></td>
			<td>photo and design software</td>
		</tr>
		<tr>
			<td>Rhinoceros 3D</td>
			<td>Robert McNeel &#38; Associates</td>
			<td>version 7.0</td>
			<td>3D design software</td>
		</tr>
		<tr>
			<td>TC20 Automated Cell Counter</td>
			<td>Bio-Rad</td>
			<td>TC20</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin</td>
			<td>Cytiva&#160;HyClone, United State</td>
			<td>SH30042.01</td>
			<td></td>
		</tr>
	</tbody>
</table>

a tool to automatically create stable and reproducible cell-free gaps for improving the reliability of cell wound healing assay

<meta charset="utf8"></head><body>作者聚焦：使用交互体验设计和用户需求分析设计创新的细胞抓取器

一种自动创建稳定且可重现的无细胞间隙的工具，用于提高细胞伤口愈合测定的可靠性

The reliability of cellular migration measurement in wound healing assays is frequently undermined by the prevalent methodological instability, i.e., ...

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Research

A Tool to Automatically Create Stable and Reproducible Cell-free Gaps for Improving the Reliability of Cell Wound Healing Assay

JoVE Journal

Biology

337 次观看.  Kunming University of Science and Technology. 通过结合交互体验设计和用户需求分析，我们推出了一种创新的细胞刮虫，可在可重复性、可靠性、实用性、细胞完整性和用户体验方面增强细胞伤口愈合测定。我们授权了 Consultative Rhinal、Keystone 和 Photocell 进行产品可视化。这种方法不仅在预生产实际产品，而且我们加强了团队成员之间的沟通。此外，它还有助于降低全年总成本。在实验验?...

视频: 作者聚焦：使用交互体验设计和用户需求分析设计创新的细胞抓取器

Visualizing Cytoplasmic Flow During Single-cell Wound Healing in Stentor coeruleus

Although wound-healing is often addressed at the level of whole tissues, in many cases individual cells are able to heal wounds within themselves, repairing broken cell membrane before the cellular contents leak out. The giant unicellular organism Stentor coeruleus, in which cells can be more than one millimeter in size, have been a classical model organism for studying wound healing in single cells. Stentor cells can be cut in half without loss of viability, and can even be cut and grafted together. But this high tolerance to cutting raises the question of why the cytoplasm does not simply flow out from the size of the cut. Here we present a method for cutting Stentor cells while simultaneously imaging the movement of cytoplasm in the vicinity of the cut at high spatial and temporal resolution. The key to our method is to use a &#34;double decker&#34; microscope configuration in which the surgery is performed under a dissecting microscope focused on a chamber that is simultaneously viewed from below at high resolution using an inverted microscope with a high NA lens. This setup allows a high level of control over the surgical procedure while still permitting high resolution tracking of cytoplasm.

Visualizing Cytoplasmic Flow During Single-cell Wound Healing in Stentor coeruleus

The giant ciliate Stentor coeruleus is a classical system for studying regeneration and wound healing in single cells.&#160;By imaging Stentor cells simultaneously at low and high magnification it is possible to measure cytoplasmic flows before, during, and after wounding.

可视化细胞质流动过程中单细胞伤口愈合<em&gt;蓝斑宏声</em

Although wound-healing is often addressed at the level of whole tissues, in many cases individual cells are able to heal wounds within themselves, ...

科研

生物学

Assaying Proteasomal Degradation in a Cell-free System in Plants

The ubiquitin-proteasome pathway for protein degradation has emerged as one of the most important mechanisms for regulation of a wide spectrum of cellular functions in virtually all eukaryotic organisms. Specifically, in plants, the ubiquitin/26S proteasome system (UPS) regulates protein degradation and contributes significantly to development of a wide range of processes, including immune response, development and programmed cell death. Moreover, increasing evidence suggests that numerous plant pathogens, such as Agrobacterium, exploit the host UPS for efficient infection, emphasizing the importance of UPS in plant-pathogen interactions.
The substrate specificity of UPS is achieved by the E3 ubiquitin ligase that acts in concert with the E1 and E2 ligases to recognize and mark specific protein molecules destined for degradation by attaching to them chains of ubiquitin molecules. One class of the E3 ligases is the SCF (Skp1/Cullin/F-box protein) complex, which specifically recognizes the UPS substrates and targets them for ubiquitination via its F-box protein component. To investigate a potential role of UPS in a biological process of interest, it is important to devise a simple and reliable assay for UPS-mediated protein degradation. Here, we describe one such assay using a plant cell-free system. This assay can be adapted for studies of the roles of regulated protein degradation in diverse cellular processes, with a special focus on the F-box protein-substrate interactions.

Targeted protein degradation represents a major regulatory mechanism for cell function. It occurs via a conserved ubiquitin-proteasome pathway, which attaches polyubiquitin chains to the target protein that then serve as molecular &#8220;tags&#8221; for the 26S proteasome. Here, we describe a simple and reliable cell-free assay for proteasomal degradation of proteins.

测定蛋白酶体降解的植物无细胞系统

The ubiquitin-proteasome pathway for protein degradation has emerged as one of the most important mechanisms for regulation of a wide spectrum of cellular ...

A Cell Free Assay to Study Chromatin Decondensation at the End of Mitosis

During the vertebrate cell cycle chromatin undergoes extensive structural and functional changes. Upon mitotic entry, it massively condenses into rod shaped chromosomes which are moved individually by the mitotic spindle apparatus. Mitotic chromatin condensation yields chromosomes compacted fifty-fold denser as in interphase. During exit from mitosis, chromosomes have to re-establish their functional interphase state, which is enclosed by a nuclear envelope and is competent for replication and transcription. The decondensation process is morphologically well described, but in molecular terms poorly understood: We lack knowledge about the underlying molecular events and to a large extent the factors involved as well as their regulation. We describe here a cell-free system that faithfully recapitulates chromatin decondensation in vitro, based on mitotic chromatin clusters purified from synchronized HeLa cells and X. laevis egg extract. Our cell-free system provides an important tool for further molecular characterization of chromatin decondensation and its co-ordination with processes simultaneously occurring during mitotic exit such as nuclear envelope and pore complex re-assembly.

The molecular mechanisms of the decondensation of highly compacted mitotic chromatin are ill-defined. We present a cell-free assay based on mitotic chromatin clusters isolated from HeLa cells and Xenopus laevis egg extract that faithfully reconstitutes the decondensation process in vitro.

无细胞化验，研究染色质解聚在有丝分裂的结束

During the vertebrate cell cycle chromatin undergoes extensive structural and functional changes. Upon mitotic entry, it massively condenses into rod ...

A Cell-Free Assay Using Xenopus laevis Embryo Extracts to Study Mechanisms of Nuclear Size Regulation

A fundamental question in cell biology is how cell and organelle sizes are regulated. It has long been recognized that the size of the nucleus generally scales with the size of the cell, notably during embryogenesis when dramatic reductions in both cell and nuclear sizes occur. Mechanisms of nuclear size regulation are largely unknown and may be relevant to cancer where altered nuclear size is a key diagnostic and prognostic parameter. In vivo approaches to identifying nuclear size regulators are complicated by the essential and complex nature of nuclear function. The in vitro approach described here to study nuclear size control takes advantage of the normal reductions in nuclear size that occur during Xenopus laevis development. First, nuclei are assembled in X. laevis egg extract. Then, these nuclei are isolated and resuspended in cytoplasm from late stage embryos. After a 30 - 90 min incubation period, nuclear surface area decreases by 20 - 60%, providing a useful assay to identify cytoplasmic components present in late stage embryos that contribute to developmental nuclear size scaling. A major advantage of this approach is the relative facility with which the egg and embryo extracts can be biochemically manipulated, allowing for the identification of novel proteins and activities that regulate nuclear size. As with any in vitro approach, validation of results in an in vivo system is important, and microinjection of X. laevis embryos is particularly appropriate for these studies.

A Cell-Free Assay Using Xenopus laevis Embryo Extracts to Study Mechanisms of Nuclear Size Regulation

Mechanisms of cellular and intra-cellular scaling remain elusive. The use of Xenopus embryo extracts has become increasingly common to elucidate mechanisms of organelle size regulation. This method describes embryo extract preparation and a novel nuclear scaling assay through which mechanisms of nuclear size regulation can be identified.

无细胞测定中使用<em&gt;非洲爪蟾</em&gt;胚胎提取研究核的大小调节机制。

A fundamental question in cell biology is how cell and organelle sizes are regulated. It has long been recognized that the size of the nucleus generally ...

Visualization and Quantification of the Cell-free Layer in Arterioles of the Rat Cremaster Muscle

The cell-free layer is defined as the parietal plasma layer in the microvessel flow, which is devoid of red blood cells. The measurement of the in vivo cell-free layer width and its spatiotemporal variations can provide a comprehensive understanding of hemodynamics in microcirculation. In this study, we used an intravital microscopic system coupled with a high-speed video camera to quantify the cell-free layer widths in arterioles in vivo. The cremaster muscle of Sprague-Dawley rats was surgically exteriorized to visualize the blood flow. A custom-built imaging script was also developed to automate the image processing and analysis of the cell-free layer width. This approach enables the quantification of spatiotemporal variations more consistently than previous manual measurements. The accuracy of the measurement, however, partly depends on the use of a blue filter and the selection of an appropriate thresholding algorithm. Specifically, we evaluated the contrast and quality of images acquired with and without the use of a blue filter. In addition, we compared five different image histogram-based thresholding algorithms (Otsu, minimum, intermode, iterative selection, and fuzzy entropic thresholding) and illustrated the differences in their determination of the cell-free layer width.

This study demonstrates the surgical preparation of the rat cremaster muscle for the visualization of the in vivo cell-free layer. Considerable factors affecting the accuracy of the cell-free layer width measurement are discussed in this study.

在大鼠提睾肌的小动脉的可视化和量化的无细胞层

The cell-free layer is defined as the parietal plasma layer in the microvessel flow, which is devoid of red blood cells. The measurement of the in vivo ...

Improving the Accuracy of Flow Cytometric Assessment of Mitochondrial Membrane Potential in Hematopoietic Stem and Progenitor Cells Through the Inhibition of Efflux Pumps

As cellular metabolism is a key regulator of hematopoietic stem cell (HSC) self-renewal, the various roles played by the mitochondria in hematopoietic homeostasis have been extensively studied by HSC researchers. Mitochondrial activity levels are reflected in their membrane potentials (&#916;&#936;m), which can be measured by cell-permeant cationic dyes such as TMRM (tetramethylrhodamine, methyl ester). The ability of efflux pumps to extrude these dyes from cells can limit their usefulness, however. The resulting measurement bias is particularly critical when assessing HSCs, as xenobiotic transporters exhibit higher levels of expression and activity in HSCs than in differentiated cells. Here, we describe a protocol utilizing Verapamil, an efflux pump inhibitor, to accurately measure &#916;&#936;m across multiple bone marrow populations. The resulting inhibition of pump activity is shown to increase TMRM intensity in hematopoietic stem and progenitor cells (HSPCs), while leaving it relatively unchanged in mature fractions. This highlights the close attention to dye-efflux activity that is required when &#916;&#936;m-dependent dyes are used, and as written and visualized, this protocol can be used to accurately compare either different populations within the bone marrow, or the same population across different experimental models.

Xenobiotic efflux pumps are highly active in hematopoietic stem and progenitor cells (HSPCs) and cause extrusion of TMRM, a mitochondrial membrane potential fluorescent dye. Here, we present a protocol to accurately measure mitochondrial membrane potential in HSPCs by TMRM in the presence of Verapamil, an efflux pump inhibitor.

通过抑制Efflux泵,提高造血干细胞和造血细胞中线粒体膜电位流细胞测定的准确性

As cellular metabolism is a key regulator of hematopoietic stem cell (HSC) self-renewal, the various roles played by the mitochondria in hematopoietic ...

Zebrafish Corneal Wound Healing: From Abrasion to Wound Closure Imaging Analysis

As the transparent surface of the eye, the cornea is instrumental for clear sight. Due to its location, this tissue is prone to environmental insults. Indeed, the eye injuries most frequently encountered clinically are those to the cornea. While corneal wound healing has been extensively studied in small mammals (i.e., mice, rats, and rabbits), corneal physiology studies have neglected other species, including zebrafish, despite zebrafish being a classic research model.
This report describes a method of performing a corneal abrasion on zebrafish. The wound is performed in vivo on anesthetized fish using an ocular burr. This method allows for a reproducible epithelial wound, leaving the rest of the eye intact. After abrasion, wound closure is monitored over the course of 3 h, after which the wound is reepithelialized. By using scanning electron microscopy, followed by image processing, the epithelial cell shape, and apical protrusions can be investigated to study the various steps during corneal epithelial wound closure.
The characteristics of the zebrafish model permit study of the epithelial tissue physiology and the collective behavior of the epithelial cells when the tissue is challenged. Furthermore, the use of a model deprived of the influence of the tear film can produce&#160;new answers regarding corneal response to stress. Finally, this model also allows the delineation of the cellular and molecular events involved in any epithelial tissue subjected to a physical wound. This method can be applied to the evaluation of drug effectiveness in preclinical testing.

This protocol focuses on damaging the ocular surface of zebrafish through abrasion to assess the subsequent wound closure at the cellular level. This approach exploits an ocular burr to partly remove the corneal epithelium and uses scanning electron microscopy to track changes in cell morphology during wound closure.

斑马鱼角膜伤口愈合：从磨损到伤口闭合成像分析

As the transparent surface of the eye, the cornea is instrumental for clear sight. Due to its location, this tissue is prone to environmental insults. ...

Assessment of Bone Fracture Healing Using Micro-Computed Tomography

Micro-computed tomography (&#181;CT) is the most common imaging modality to characterize the three-dimensional (3D) morphology of bone and newly formed bone during fracture healing in translational science investigations. Studies of long bone fracture healing in rodents typically involve secondary healing and the formation of a mineralized callus. The shape of the callus formed and the density of the newly formed bone may vary substantially between timepoints and treatments. Whereas standard methodologies for quantifying parameters of intact cortical and trabecular bone are widely used and embedded in commercially available software, there is a lack of consensus on procedures for analyzing the healing callus. The purpose of this work is to describe a standardized protocol that quantitates bone volume fraction and callus mineral density in the healing callus. The protocol describes different parameters that should be considered during imaging and analysis, including sample alignment during imaging, the size of the volume of interest, and the number of slices that are contoured to define the callus.

Micro-computed tomography (&#181;CT) is a non-destructive imaging tool that is instrumental in assessing bone structure in preclinical studies, however there is a lack of consensus on &#181;CT procedures for analyzing the bone healing callus. This study provides a step-by-step &#181;CT protocol that allows the monitoring of fracture healing.

使用显微计算机断层扫描评估骨折愈合

Micro-computed tomography (&#181;CT) is the most common imaging modality to characterize the three-dimensional (3D) morphology of bone and newly formed ...

Characterizing Epithelial Wound Healing In Vivo Using the Cnidarian Model Organism Clytia hemisphaerica

All animal organs, from the skin to eyes to intestines, are covered with sheets of epithelial cells that allow them to maintain homeostasis while protecting them from infection. Therefore, it is not surprising that the ability to repair epithelial wounds is critical to all metazoans. Epithelial wound healing in vertebrates involves overlapping processes, including inflammatory responses, vascularization, and re-epithelialization. Regulation of these processes involves complex interactions between epithelial cells, neighboring cells, and the extracellular matrix (ECM); the ECM contains structural proteins, regulatory proteins, and active small molecules. This complexity, together with the fact that most animals have opaque tissues and inaccessible ECMs, makes wound healing difficult to study in live animals. Much work on epithelial wound healing is therefore performed in tissue culture systems, with a single epithelial cell-type plated as a monolayer on an artificial matrix. Clytia hemisphaerica (Clytia) provides a unique and exciting complement to these studies, allowing epithelial wound healing to be studied in an intact animal with an authentic ECM. The ectodermal epithelium of Clytia is a single layer of large squamous epithelial cells, allowing high-resolution imaging using differential interfering contrast (DIC) microscopy in living animals. The absence of migratory fibroblasts, vasculature, or inflammatory responses makes it possible to dissect the critical events in re-epithelialization in vivo. The healing of various types of wounds can be analyzed, including single-cell microwounds, small and large epithelial wounds, and wounds that damage the basement membrane. Lamellipodia formation, purse string contraction, cell stretching, and collective cell migration can all be observed in this system. Furthermore, pharmacological agents can be introduced via the ECM to modify cell:ECM interactions and cellular processes in vivo. This work shows methods for creating wounds in live Clytia, capturing movies of healing, and probing healing mechanisms by microinjecting reagents into the ECM.

Characterizing Epithelial Wound Healing In Vivo Using the Cnidarian Model Organism Clytia hemisphaerica

This paper describes a method to create wounds in the epithelium of a live Clytia hemisphaerica medusa and image wound healing at a high resolution in vivo. Additionally, a technique to introduce dyes and drugs to perturb signaling processes in the epithelial cells and extracellular matrix during wound healing is presented.

使用刺胞动物模式生物Clytia hemisphaerica表征体内上皮伤口愈合

All animal organs, from the skin to eyes to intestines, are covered with sheets of epithelial cells that allow them to maintain homeostasis while ...

将 CFPS 反应包埋在各种水凝胶基质中

Methods for Embedding Cell-Free Protein Synthesis Reactions in Macro-Scale Hydrogels

Synthetic gene networks provide a platform for scientists and engineers to design and build novel systems with functionality encoded at a genetic level. While the dominant paradigm for the deployment of gene networks is within a cellular chassis, synthetic gene networks may also be deployed in cell-free environments. Promising applications of cell-free gene networks include biosensors, as these devices have been demonstrated against biotic (Ebola, Zika, and SARS-CoV-2 viruses) and abiotic (heavy metals, sulfides, pesticides, and other organic contaminants) targets. Cell-free systems are typically deployed in liquid form within a reaction vessel. Being able to embed such reactions in a physical matrix, however, may facilitate their broader application in a wider set of environments. To this end, methods for embedding cell-free protein synthesis (CFPS) reactions in a variety of hydrogel matrices have been developed. One of the key properties of hydrogels conducive to this work is the high-water reconstitution capacity of hydrogel materials. Additionally, hydrogels possess physical and chemical characteristics that are functionally beneficial. Hydrogels can be freeze-dried for storage and rehydrated for use later. Two step-by-step protocols for the inclusion and assay of CFPS reactions in hydrogels are presented. First, a CFPS system can be incorporated into a hydrogel via rehydration with a cell lysate. The system within the hydrogel can then be induced or expressed constitutively for complete protein expression through the hydrogel. Second, cell lysate can be introduced to a hydrogel at the point of polymerization, and the entire system can be freeze-dried and rehydrated at a later point with an aqueous solution containing the inducer for the expression system encoded within the hydrogel. These methods have the potential to allow for cell-free gene networks that confer sensory capabilities to hydrogel materials, with the potential for deployment beyond the laboratory.

作者聚焦：一种在水凝胶中包埋无细胞蛋白质合成反应的新方法 

Here, we present two protocols for embedding cell-free protein synthesis reactions in macro-scale hydrogel matrices without the need for an external liquid phase.

在宏观水凝胶中包埋无细胞蛋白质合成反应的方法

Synthetic gene networks provide a platform for scientists and engineers to design and build novel systems with functionality encoded at a genetic level. ...