Name: saturated fatty acids induce ceramide-associated macrophage cell death
Uploaded: 2017-10-31T15:00:00.000+00:00
Duration: 8 min 26 s
Description: Watch this Scientific Journal Video about Saturated Fatty Acids Induce Ceramide-associated Macrophage Cell Death at JoVE.com

这项工作由路易斯维尔大学启动基金和国立癌症研究所 (R01CA177679, R01CA180986) 资助。

该议定书得到了路易斯维尔大学机构动物保育和使用委员会 (IACUC) 的批准. 
 1. 小鼠骨髓衍生巨噬细胞 (BMDMs) <ol> <li> 安乐 6-至8周, 健康的野生型鼠标使用 CO 2 。把它钉在泡沫板上, 用70% 乙醇喷洒, 直到它被浸湿。用钳子和剪刀取出胫骨/股骨骨。用5毫升1x 磷酸缓冲盐水 (PBS) 将它们放入培养皿中。在无菌条件下执行所有程序. </li>
	<li> 在无菌组织培养罩中用剪刀切开胫骨/股骨骨的两端。将25克针与 PBS + 2% 胎牛血清 (FBS) 一起冲洗到15毫升管中. </li>
	<li> 在 500 x g、4和 #176 上离心骨髓细胞; C 为5分钟. </li>
	<li> 重1毫升红细胞裂解缓冲液中的细胞团溶解红细胞 (RBC) 少于1分钟, 立即用9毫升 1x PBS 稀释。再离心和在步1.3。醒酒清. </li>
	<li> 重10毫升 1x PBS 中的细胞颗粒, 通过不育的40和 #956 过滤细胞悬浮; #160; 尼龙网进入另一个15毫升管去除细胞碎片/团簇。再离心机作为在1.3。醒酒清. </li>
	<li> 重15毫升罗斯威尔公园纪念研究所中型 (RPMI) 1640 与 5% FBS 和10和 #956 的细胞颗粒; 庆大霉素, 将100毫米的组织培养皿中的细胞放在 37 o C 孵化箱中, 60 分钟. 轻轻地旋转盘子, 取出漂浮单元格, 并对它们进行计数. </li>
	<li> 板 6x10 6 12 毫升巨噬细胞分化培养基的100毫米盘中的细胞 (RPMI 1640 与 5% FBS 和10和 #956; 庆大霉素, 混合 30% L929 条件培养基 10 ) 与 10 ng/毫升重组小鼠巨噬细胞集落刺激因子 (M CSF) 为2天. </li>
	<li> 在37和 #176 中培养了2天后; C 孵化器与 5% CO 2 , 用6毫升新鲜巨噬细胞与 10 ng/毫升 M-CSF 喂养每道菜. </li>
	<li> 在5天, 采取8毫升的旧媒体, 而不干扰细胞和增加10毫升新鲜巨噬细胞分化介质与 10 ng/毫升 M-CSF. </li>
	<li> 在7天, 使用细胞提升器获取骨髓衍生巨噬细胞 (BMDMs). 
	注: 在 1x pbs 中, 附加的巨噬细胞也可与5毫升1毫米的 EDTA 分离, 5 至10分钟, 去除浮点数和洗涤板两次, 与5毫升 1x pbs。离心机的细胞, 在步骤 1.3., 重他们在新鲜巨噬细胞区分媒体, 并数他们与例。
	<ol> <li> 确认 BMDMs 和 #39; 表型由流式细胞仪描述为 5 。准备在一定浓度下的衍生小鼠巨噬细胞进行以下研究. </li>
	</ol> </li> </ol> 2。脂肪酸共轭制剂 <ol> <li> 在无菌 PBS 中制备2毫米 bsa。例如, 重6.65 克 bsa, 加入30毫升 1x pbs, 以解散, 然后添加更多的 pbs, 直到50毫升, 缩放组件, 使2毫米 bsa 在 1x pbs. </li>
	<li> 在2毫米 BSA 中制备5毫米的脂肪酸单独钠盐。加热到37和 #176; C 或更高, 如有必要, 几种2毫米 BSA 和脂肪酸钠的混合物, 直到得到明确的溶液为止. 
	注: 与不饱和脂肪酸相比, 饱和脂肪酸需要更高的温度和更超声的溶解时间. </li>
	<li> 通过0.22 和 #956 过滤脂肪酸 BSA 溶液, 将其分为1.5 毫升无菌离心管, 并将其存储在4和 #176; c 用于短期或-20 和 #176; c 用于长期存储。4、#176 贮存后不应出现降水. </li>
</ol> 3。饱和脂肪酸诱导小鼠骨髓源性巨噬细胞死亡的研究 <ol> <li> 在巨噬细胞分化介质中的24个组织培养板中 BMDMs 0.4 x 10 6 /毫升. </li>
	<li> 将 0.4 mM 棕榈酸和硬脂酸的细胞处理为16到24小时, 在37和 #176; C 孵化器与 5% CO 2 。使用 BSA 作为负控制. </li>
	<li> 在治疗后用细胞升降器采集细胞, 并在 500 x g、4和 #176 中旋转细胞; C 为5分钟. </li>
	<li> 在100和 #956 中用蛋白 v-Alexa 488 和 7-aminoactinomycin D (7-反倾销) 对细胞进行染色; 在室温下为15分钟蛋白 v 绑定缓冲区. </li>
	<li> 用200和 #181 稀释样品; 蛋白结合缓冲液, 轻轻搅拌, 在潜伏期后将样品保存在冰上. </li>
	<li> 通过流式细胞仪来尽快分析染色细胞 5 。在 FITC 通道中检测到蛋白 V-Alexa 488, 在 PerCP/PerCP-Cy5.5 通道中检测到 7-反倾销. </li>
</ol> 4。胞内神经酰胺染色 <ol> <li> 在脂肪酸处理后, 在步骤3.3 中收获细胞。然后将4% 甲醛中的单元格修复为 30 min. </li>
	<li> 用1毫升 1x PBS 清洗样品, 在3.3 中向下旋转一步, 醒酒上清液. </li>
	<li> 在100和 #956 中用 anti-ceramide 原抗体 (1:200 稀释) 将细胞染色; L 1x 性缓冲30分钟 </li>
	<li> 在步骤4.2 中再次清洗和旋转单元格. </li>
	<li> 在100和 #956 中用 anti-mouse IgM 二次抗体 (1:500 稀释) 将细胞染色; L 1x 性缓冲器30分钟 </li>
	<li> 在步骤4.2 中再次清洗和旋转单元格。添加250和 #956; 1x PBS 并通过流式细胞仪分析染色细胞 5 . 
	注: 请参阅设备和试剂表中的详细试剂清单. </li>
</ol>

<ol>
	<li>Martins de Lima, T., Cury-Boaventura, M. F., Giannocco, G., Nunes, M. T., Curi, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+toxicity+of+fatty+acids+on+a+macrophage+cell+line+(J774).">Comparative toxicity of fatty acids on a macrophage cell line (J774).</a> Clin Sci (Lond). 111 (5), 307-317 (2006).</li><li>Simard, J. R., Zunszain, P. A., Hamilton, J. A., Curry, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Location+of+high+and+low+affinity+fatty+acid+binding+sites+on+human+serum+albumin+revealed+by+NMR+drug-competition+analysis.">Location of high and low affinity fatty acid binding sites on human serum albumin revealed by NMR drug-competition analysis.</a> J Mol Biol. 361 (2), 336-351 (2006).</li><li>Penn, A. H., Dubick, M. A., Torres Filho, I. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fatty+Acid+Saturation+of+Albumin+Used+in+Resuscitation+Fluids+Modulates+Cell+Damage+in+Shock:+In+Vitro+Results+Using+a+Novel+Technique+to+Measure+Fatty+Acid+Binding+Capacity.">Fatty Acid Saturation of Albumin Used in Resuscitation Fluids Modulates Cell Damage in Shock: In Vitro Results Using a Novel Technique to Measure Fatty Acid Binding Capacity.</a> Shock. , (2017).</li><li>Vusse, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Albumin+as+fatty+acid+transporter.">Albumin as fatty acid transporter.</a> Drug Metab Pharmacokinet. 24 (4), 300-307 (2009).</li><li>Zhang, Y., 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=Adipose+Fatty+Acid+Binding+Protein+Promotes+Saturated+Fatty+Acid-Induced+Macrophage+Cell+Death+through+Enhancing+Ceramide+Production.">Adipose Fatty Acid Binding Protein Promotes Saturated Fatty Acid-Induced Macrophage Cell Death through Enhancing Ceramide Production.</a> J Immunol. 198 (2), 798-807 (2017).</li><li>Zhang, Y., 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=Epidermal+Fatty+Acid+binding+protein+promotes+skin+inflammation+induced+by+high-fat+diet.">Epidermal Fatty Acid binding protein promotes skin inflammation induced by high-fat diet.</a> Immunity. 42 (5), 953-964 (2015).</li><li>Wen, 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=Fatty+acid-induced+NLRP3-ASC+inflammasome+activation+interferes+with+insulin+signaling.">Fatty acid-induced NLRP3-ASC inflammasome activation interferes with insulin signaling.</a> Nat Immunol. 12 (5), 408-415 (2011).</li><li>Zhang, Y., 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=Fatty+acid-binding+protein+E-FABP+restricts+tumor+growth+by+promoting+IFN-beta+responses+in+tumor-associated+macrophages.">Fatty acid-binding protein E-FABP restricts tumor growth by promoting IFN-beta responses in tumor-associated macrophages.</a> Cancer Res. 74 (11), 2986-2998 (2014).</li><li>Ulloth, J. E., Casiano, C. A., De Leon, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Palmitic+and+stearic+fatty+acids+induce+caspase-dependent+and+-independent+cell+death+in+nerve+growth+factor+differentiated+PC12+cells.">Palmitic and stearic fatty acids induce caspase-dependent and -independent cell death in nerve growth factor differentiated PC12 cells.</a> J Neurochem. 84 (4), 655-668 (2003).</li><li>Weischenfeldt, J., Porse, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+Marrow-Derived+Macrophages+(BMM):+Isolation+and+Applications.">Bone Marrow-Derived Macrophages (BMM): Isolation and Applications.</a> CSH Protoc. , (2008).</li><li>Dansen, T. 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作者声明没有利益的财政冲突。

正确制备脂肪酸溶液对研究脂肪酸的生物学功能具有重要意义。脂肪酸的中和性增加了其在水溶液中的溶解度。然而, 我们观察到, 脂肪酸的钠盐, 特别是饱和脂肪酸, 在水或 PBS 中的溶解度仍然很低。一种方法是使用 95-100% 乙醇来帮助溶解脂肪酸1。使用这种方法, 即使在较低浓度的低毒性不饱和脂肪酸, 对细胞的毒性也会更高。另一种制备脂肪酸溶液的方法是利用甲基β-环糊精作?...

脂肪酸在能量代谢和不同类型细胞的膜磷脂合成中起着至关重要的作用。脂肪酸具有低水溶性。适当制备脂肪酸对研究哺乳动物细胞中脂肪酸的生物学功能具有重要意义。当脂肪酸准备用乙醇, 许多脂肪酸可能显示其有毒肥皂 (洗涤剂) 对细胞膜的影响, 即使在相对较低的浓度1。作为一个天然的, 主要运输者为游离脂肪酸在血清中, 血清白蛋白被认为是一个很好的载体脂肪酸传递在体外的脂肪酸功能检测2,3,4。然而, 尽管许多使用脂肪酸的研究论文已经出版, 但关于脂肪酸和血清白蛋白共轭物的制备的细节通常是不可用的。
巨噬细胞高表达表皮脂肪酸结合蛋白和脂肪脂肪酸结合蛋白5,6,7,8。他们积极摄取饱和和不饱和脂肪酸, 这可能调节他们的免疫功能。为了研究脂肪酸对巨噬细胞和其他组织的影响, 采用了不同的脂肪酸制备方法1,7,9。使用适当制备的脂肪酸/血清白蛋白结合物来研究脂肪酸对巨噬细胞功能的影响, 对于获得具有生物学意义的数据至关重要。研究脂肪酸对巨噬细胞功能的影响, 可为巨噬细胞相关疾病的脂肪酸代谢提供基础知识和潜在的治疗靶点。

<table><tbody><tr><td>CPX Ultrasonic Bath&amp;nbsp;</td><td>Bransonic</td><td>Model 2800</td><td></td></tr><tr><td>Sodium palmitate (PA)</td><td>Nu-Chek Prep, Inc.</td><td>S-1109</td><td>M.W. 278</td></tr><tr><td>Sodium stearate (SA)</td><td>Nu-Chek Prep, Inc.</td><td>S-1111</td><td>M.W. 306</td></tr><tr><td>Bovine serum albumin (BSA), fatty acid-free</td><td>Fisher Scientific</td><td>9048-46-8</td><td></td></tr><tr><td>Mouse macrophage colony stimulating factor (mM-CSF)&amp;nbsp;</td><td>Cell Signaling Technology,&amp;nbsp; Inc.</td><td>5228</td><td></td></tr><tr><td>RPMI 1640</td><td>VWR International</td><td>71002-878</td><td></td></tr><tr><td>Annexin V, Alexa Fluor 488 conjugate</td><td>Fisher Scientific</td><td>A13201</td><td></td></tr><tr><td>7-AAD</td><td>BD Biosciences</td><td>559925</td><td></td></tr><tr><td>Monoclonal anti-ceramide antibody (mouse IgM)</td><td>Sigma</td><td>C8104-50TST</td><td>Clone: MID 15B4</td></tr><tr><td>Goat Anti-Mouse IgM Antibody, &amp;micro; chain, FITC conjugate</td><td>Sigma</td><td>AP128F</td><td></td></tr><tr><td>Fixation buffer</td><td>Biolegend</td><td>420801</td><td></td></tr><tr><td>Permeabilization buffer</td><td>Ebioscience</td><td>4307693</td><td></td></tr><tr><td>Red Blood Cell Lysis Buffer&amp;nbsp;</td><td>Sigma</td><td>11814389001</td><td></td></tr><tr><td>Annexin V Binding Buffer</td><td>BD Biosciences</td><td>556454</td><td></td></tr><tr><td>L929 cells</td><td>ATCC</td><td>CCL-1</td><td></td></tr><tr><td>Corning&amp;nbsp;Cell Lifter&amp;nbsp;</td><td>Fisher Scientific</td><td>07-200-364</td><td></td></tr><tr><td>Note: M.W. is for molecular weight.</td><td></td><td></td><td></td></tr></tbody></table>

saturated fatty acids induce ceramide-associated macrophage cell death

巨噬细胞高表达表皮脂肪酸结合蛋白和脂肪脂肪酸结合蛋白。他们积极摄取饱和和不饱和脂肪酸, 这可能在调节其免疫功能方面起到关键作用。许多研究表明, 各种脂肪酸, 饱和或不饱和, 可能对细胞生长和功能有不同的影响。然而, 用于脂肪酸制备的方法各不相同, 这可能导致 non-physiological 的结果。血清白蛋白是哺乳动物外周血中脂肪酸的天然载体, 推荐用脂肪酸钠盐组成共轭络合物, 研究哺乳动物细胞中的脂肪酸功能, 从而最大限度地减少脂肪酸皂的毒性。因此, 本文提出了一种简单、相对快速的加热和 sonicating 方法, 用于 BSA-脂肪酸共轭形成。我们描述了一个协议使用饱和脂肪酸, 特别是硬脂酸, 以诱导在小鼠骨髓衍生巨噬细胞死亡严重。我们进一步证明饱和脂肪酸诱导的细胞死亡与积累的细胞神经酰胺水平呈正相关。这种方法可以扩展到研究脂肪酸对其他哺乳动物细胞的影响。

肥胖会增加血清中游离脂肪酸的浓度。作为专业的吞噬, 巨噬细胞积极地服用脂肪酸来维持宿主的稳态。在这些过程中, 超负荷的脂质可能导致巨噬细胞死亡。为此, 我们培养 BMDMs体外与肥胖水平的膳食脂肪酸和测量巨噬细胞死亡使用流细胞染色。与 BSA 控制相比, 饱和脂肪酸, 特别是硬脂酸, 诱导 BMDMs 细胞死亡. 死细胞显示为双阳性种群染色的蛋白 V 和 7-反倾销 (<stron...

Watch this Scientific Journal Video about Saturated Fatty Acids Induce Ceramide-associated Macrophage Cell Death at JoVE.com

Saturated Fatty Acids Induce Ceramide-associated Macrophage Cell Death

本文阐述了一种从骨髓细胞中提取小鼠原发巨噬蛋白的方法, 并提出了制备 BSA-脂肪酸共轭物的简便方法。然后我们证明饱和脂肪酸能诱导巨噬细胞死亡, 这种细胞死亡与神经酰胺水平的细胞积累呈正相关。

饱和脂肪酸诱导神经酰胺相关巨噬细胞死亡

Macrophages highly express epidermal fatty acid-binding protein and adipose fatty acid-binding protein. They actively uptake saturated and unsaturated ...

saturated-fatty-acids-induce-ceramide-associated-macrophage-cell-death

Research

JoVE Journal

Immunology and Infection

9.2K 次观看.  University of Louisville. 本文阐述了一种从骨髓细胞中提取小鼠原发巨噬蛋白的方法, 并提出了制备 BSA-脂肪酸共轭物的简便方法。然后我们证明饱和脂肪酸能诱导巨噬细胞死亡, 这种细胞死亡与神经酰胺水平的细胞积累呈正相关。

视频: Saturated Fatty Acids Induce Ceramide-associated Macrophage Cell Death

Isolation, Characterization, and Purification of Macrophages from Tissues Affected by Obesity-related Inflammation

Obesity promotes a chronic inflammatory state that is largely mediated by tissue-resident macrophages as well as monocyte-derived macrophages. Diet-induced obesity (DIO) is a valuable model in studying the role of macrophage heterogeneity; however, adequate macrophage isolations are difficult to acquire from inflamed tissues. In this protocol, we outline the isolation steps and necessary troubleshooting guidelines derived from our studies for obtaining a suitable population of tissue-resident macrophages from mice following 18 weeks of high-fat (HFD) or high-fat/high-cholesterol (HFHCD) diet intervention. This protocol focuses on three hallmark tissues studied in obesity and atherosclerosis including the liver, white adipose tissues (WAT), and the aorta. We highlight how dualistic usage of flow cytometry can achieve a new dimension of isolation and characterization of tissue-resident macrophages. A fundamental section of this protocol addresses the intricacies underlying tissue-specific enzymatic digestions and macrophage isolation, and subsequent cell-surface antibody staining for flow cytometric analysis. This protocol addresses existing complexities underlying fluorescent-activated cell sorting (FACS) and presents clarifications to these complexities so as to obtain broad range characterization from adequately sorted cell populations. Alternate enrichment methods are included for sorting cells, such as the dense liver, allowing for flexibility and time management when working with FACS. In brief, this protocol aids the researcher to evaluate macrophage heterogeneity from a multitude of inflamed tissues in a given study and provides insightful troubleshooting tips that have been successful for favorable cellular isolation and characterization of immune cells in DIO-mediated inflammation.

This protocol allows a researcher to isolate and characterize tissue-resident macrophages in various hallmark inflamed tissues extracted from diet-induced models of metabolic disorders.

受肥胖相关炎症组织的巨噬细胞的分离、鉴定和纯化

Obesity promotes a chronic inflammatory state that is largely mediated by tissue-resident macrophages as well as monocyte-derived macrophages. ...

科研

免疫与感染

Lipid Vesicle-mediated Affinity Chromatography using Magnetic Activated Cell Sorting (LIMACS): a Novel Method to Analyze Protein-lipid Interaction

The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification procedures. As an alternative, lipids can be coated on flat surfaces as used for lipid ELISA and Plasmon resonance spectroscopy. However, surface coating lipids do not form microdomain structures, which may be important for the lipid binding properties. Further, these methods do not allow for the purification of larger amounts of proteins binding to their target lipids.
 To overcome these limitations of testing lipid protein interaction and to purify lipid binding proteins we developed a novel method termed lipid vesicle-mediated affinity chromatography using magnetic-activated cell sorting (LIMACS). In this method, lipid vesicles are prepared with the target lipid and phosphatidylserine as the anchor lipid for Annexin V MACS. Phosphatidylserine is a ubiquitous cell membrane phospholipid that shows high affinity to the protein Annexin V. Using magnetic beads conjugated to Annexin V the phosphatidylserine-containing lipid vesicles will bind to the magnetic beads. When the lipid vesicles are incubated with a cell lysate the protein binding to the target lipid will also be bound to the beads and can be co-purified using MACS. This method can also be used to test if recombinant proteins reconstitute a protein complex binding to the target lipid. 
 We have used this method to show the interaction of atypical PKC (aPKC) with the sphingolipid ceramide and to co-purify prostate apoptosis response 4 (PAR-4), a protein binding to ceramide-associated aPKC. We have also used this method for the reconstitution of a ceramide-associated complex of recombinant aPKC with the cell polarity-related proteins Par6 and Cdc42. Since lipid vesicles can be prepared with a variety of sphingo- or phospholipids, LIMACS offers a versatile test for lipid-protein interaction in a lipid environment that resembles closely that of the cell membrane. Additional lipid protein complexes can be identified using proteomics analysis of lipid binding protein co-purified with the lipid vesicles.

Lipid Vesicle-mediated Affinity Chromatography using Magnetic Activated Cell Sorting LIMACS: a Novel Method to Analyze Protein-lipid Interaction

To test the interaction of a protein with its target lipid we used MACS and Annexin V-conjugated magnetic beads and lipid vesicles synthesized from the target lipid and Annexin V-binding phosphatidylserine. Proteins bound to the target lipid are co-purified and analyzed after elution from the beads.

脂质囊泡介导的亲和层析法，使用磁性细胞分选（LIMACS）：一种新的方法来分析蛋白质 - 脂质相互作用

The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification ...

生物学

Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages

Inflammasomes are innate immune signaling platforms that are required for the successful control of many pathogenic organisms, but also promote inflammatory and autoinflammatory diseases. Inflammasomes are activated by cytosolic pattern recognition receptors, including members of the NOD-like receptor (NLR) family. These receptors oligomerize upon the detection of microbial or damage-associated stimuli. Subsequent recruitment of the adaptor protein ASC forms a microscopically visible inflammasome complex, which activates caspase-1 through proximity-induced auto-activation. Following the activation, caspase-1 cleaves pro-IL-1&#946; and pro-IL-18, leading to the activation and secretion of these pro-inflammatory cytokines. Caspase-1 also mediates the inflammatory form of cell death termed pyroptosis, which features the loss of membrane integrity and cell lysis. Caspase-1 cleaves gasdermin D, releasing the N-terminal fragment which forms plasma membrane pores, leading to osmotic lysis.
In vitro, the activation of caspase-1 can be determined by labeling bone marrow-derived macrophages with the caspase-1 activity probe FAM-YVAD-FMK and by labeling the cells with antibodies against the adaptor protein ASC. This technique allows the identification of inflammasome formation and caspase-1 activation in individual cells using fluorescence microscopy. Pyroptotic cell death can be detected by measuring the release of cytosolic lactate dehydrogenase into the medium. This procedure is simple, cost effective and performed in a 96-well plate format, allowing adaptation for screening. In this manuscript, we show that activation of the NLRP3 inflammasome by nigericin leads to the co-localization of the adaptor protein ASC and active caspase-1, leading to pyroptosis.

We describe the detection of NLRP3 inflammasome activation on cellular basis using fluorescence microscopy and staining for active caspase-1 and the adaptor, ASC. A lactate dehydrogenase release assay is presented to detect pyroptotic lysis on a population basis. These techniques can be adapted to study many aspects of inflammasome biology.

小鼠骨髓源性巨噬细胞 Inflammasome 活化和 Pyroptotic 细胞死亡的检测

Inflammasomes are innate immune signaling platforms that are required for the successful control of many pathogenic organisms, but also promote ...

Experimental Analysis of Apoptotic Thymocyte Engulfment by Macrophages

Cell apoptosis is a natural process and plays a critical role in embryonic development, homeostatic regulation, immune tolerance induction, and resolution of inflammation. Accumulation of apoptotic debris in the body may trigger chronic inflammatory responses that lead to systemic autoimmune diseases over time. Impaired apoptotic cell clearance has been implicated in a variety of autoimmune diseases. Apoptotic clearance is a complex process rarely detected under physiological conditions. It involves abundant surface receptors and signaling molecules. Studying the process of apoptotic cell clearance provides insightful molecular mechanisms and subsequent biological responses, which may lead to the development of new therapeutics. Here, we describe protocols for the induction of apoptotic thymocytes, the preparation of peritoneal macrophages, and the analysis of apoptotic cell clearance by flow cytometry and microscopy. All cells will undergo apoptosis at a certain stage, and many residential and circulating cells can uptake apoptotic debris. Therefore, the protocol described here can be used in many applications to characterize apoptotic cell binding and ingestion by many other cell types.

Here, we present a protocol to prepare apoptotic thymocytes and peritoneal macrophages and analyze the efficiency of efferocytosis and the specific inhibitor-mediated blocking of apoptotic thymocytes engulfment. This protocol has a broad application in cell-mediated clearance of other particles including artificial beads and bacteria.

巨噬细胞吞噬胸腺细胞吞噬的实验分析

Cell apoptosis is a natural process and plays a critical role in embryonic development, homeostatic regulation, immune tolerance induction, and resolution ...

Inducing and Characterizing Vesicular Steatosis in Differentiated HepaRG Cells

Hepatic steatosis represents a metabolic dysfunction that results from an accumulation of triglyceride-containing lipid droplets in hepatocytes. Excessive fat accumulation leads to non-alcoholic fatty liver disease (NAFLD), &#160;which is potentially reversible and may evolve into non-alcoholic steatohepatitis (NASH) and eventually cirrhosis and hepatocellular carcinoma (HCC). The molecular mechanisms linking lipid accumulation in hepatocytes with the progression to NASH, irreversible liver damage, fibrosis, cirrhosis, and even HCC still remains unclear. To this end, several in vitro and in vivo models have been developed to elucidate the pathological processes that cause NAFLD. In the present study, we describe a cellular model for the induction of liver vesicular steatosis that consists of DMSO-differentiated human hepatic HepaRG cells treated with the fatty acid salt sodium oleate. Indeed, sodium oleate-treated HepaRG cells accumulate lipid droplets in the cytoplasm and show typical features of steatosis. This in vitro human model represents a valuable alternative to in vivo mice models as well as to the primary human hepatocytes. We also present a comparison of several methods for the quantification and evaluation of fat accumulation in HepaRG cells, including Oil Red O staining, cytofluorimetric Bodipy measurement, metabolic gene expression analysis by qPCR, and coherent anti-Stokes Raman scattering (CARS) microscopy. CARS imaging combines the chemical specificity of Raman spectroscopy, a chemical analysis technique well-known in materials science applications, with the benefits of high-speed, high-resolution non-linear optical microscopies to allow precise quantification of lipid accumulation and lipid droplet dynamics. The establishment of an efficient in vitro model for the induction of vesicular steatosis, alongside an accurate method for the quantification and characterization of lipid accumulation, could lead to the development of early stage diagnosis of NAFLD via the identification of molecular markers, and to the generation of new treatment strategies.

In this study, we describe a detailed protocol for inducing liver vesicular steatosis in differentiated HepaRG cells with the fatty acid salt sodium oleate and employ methods for detection and quantification of lipid accumulation, including coherent anti-Stokes Raman scattering (CARS) microscopy, cytofluorimetric analysis, Oil red O staining, and qPCR.&#160;

分化肝细胞中的血管性脂细胞病的诱导和特征

Hepatic steatosis represents a metabolic dysfunction that results from an accumulation of triglyceride-containing lipid droplets in hepatocytes. Excessive ...

医学

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Cells dying by apoptosis, also referred to as regulated cell death, acquire multiple new activities that enable them to influence the function of adjacent live cells. Vital activities, such as survival, proliferation, growth, and differentiation, are among the many cellular functions modulated by apoptotic cells. The ability to recognize and respond to apoptotic cells appears to be a universal feature of all cells, regardless of lineage or organ of origination. However, the diversity and complexity of the response to apoptotic cells mandates that great care be taken in dissecting the signaling events and pathways responsible for any particular outcome. In particular, one must distinguish among the multiple mechanisms by which apoptotic cells can influence intracellular signaling pathways within viable responder cells, including: receptor-mediated recognition of the apoptotic cell, release of soluble mediators by the apoptotic cell, and/or engagement of the phagocytic machinery. Here, we provide a protocol for identifying intracellular signaling events that are induced in viable responder cells following their exposure to apoptotic cells. A major advantage of the protocol lies in the attention it pays to dissection of the mechanism by which apoptotic cells modulate signaling events within responding cells. While the protocol is specific for a conditionally immortalized mouse kidney proximal tubular cell line (BU.MPT cells), it is easily adapted to cell lines that are non-epithelial in origin and/or derived from organs other than the kidney. The use of dead cells as a stimulus introduces several unique factors that can hinder the detection of intracellular signaling events. These problems, as well as strategies to minimize or circumvent them, are discussed within the protocol. Application of this protocol should aid our expanding knowledge of the broad influence that dead or dying cells exert on their live neighbors, both in health and in disease.

Here, we present a protocol for the determination of intracellular signaling events induced in viable cells by physical interaction with adjacent dead or dying cells. The protocol focuses on signaling events induced by receptor-mediated recognition of the dead cells, as opposed to their phagocytic uptake or release of soluble mediators.

的细胞内信号与相邻小区发生细胞凋亡通过互动活细胞诱导活动标识

Cells dying by apoptosis, also referred to as regulated cell death, acquire multiple new activities that enable them to influence the function of adjacent ...

使用 Oil Red O 和 BODIPY 对脂滴大小和融合进行活细胞成像

Evaluation of Lipid Droplet Size and Fusion in Bovine Hepatic Cells

Lipid droplets (LDs) are organelles that play an important role in lipid metabolism and neutral lipid storage in cells. They are associated with a variety of metabolic diseases, such as obesity, fatty liver disease, and diabetes. In hepatic cells, the sizes and numbers of LDs are signs of fatty liver disease. Moreover, the oxidative stress reaction, cell autophagy, and apoptosis are often accompanied by changes in the sizes and numbers of LDs. As a result, the dimensions and quantity of LDs are the basis of the current research regarding the mechanism of LD biogenesis. Here, in fatty acid-induced bovine hepatic cells, we describe how to use oil red O to stain LDs and to investigate the sizes and numbers of LDs. The size distribution of LDs is statistically analyzed. The process of small LDs fusing into large LDs is also observed by a live cell imaging system. The current work provides a way to directly observe the size change trend of LDs under different physiological conditions.

作者聚焦:牛肝细胞中脂滴大小和融合的评估  

The present protocol describes how to use oil red O to dye lipid droplets (LDs), calculate the size and number of LDs in a fatty acid-induced fatty hepatocyte model, and use BODIPY 493/503 to observe the process of small LDs fusing into large LDs by live cell imaging.

牛肝细胞中脂滴大小和融合的评估

Lipid droplets (LDs) are organelles that play an important role in lipid metabolism and neutral lipid storage in cells. They are associated with a variety ...

分析 THP-1 细胞中 LPS/ATP 触发的细胞死亡机制

LPS and ATP-induced Death of PMA-differentiated THP-1 Macrophages and its Validation

Cell death is a fundamental process in all living organisms. The protocol establishes a lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced phorbol-12-myristate-13-acetate (PMA)-differentiated lipid deposition in human monocyte (THP-1) macrophage model to observe cell death. LPS combined with ATP is a classic inflammatory induction method, often used to study pyroptosis, but apoptosis and necroptosis also respond to stimulation by LPS/ATP. Under normal circumstances, phosphatidylserine is only localized in the inner leaflet of the plasma membrane. However, in the early stages of pyroptosis, apoptosis, and necroptosis, the cell membrane remains intact and exposed to phosphatidylserine, and in the later stages, the cell membrane loses its integrity. Here, flow cytometry was used to analyze Annexin V and 7-Aminoactinomycin D (AAD) double staining to detect the cell death from the whole cells. The results show&#160;that substantial cells died after stimulation with LPS/ATP. Using scanning electron microscopy, we observe the possible forms of cell death in individual cells. The results indicate that cells may undergo pyroptosis, apoptosis, or necroptosis after stimulation with LPS/ATP. This protocol focuses on observing the death of macrophages after stimulation with LPS/ATP. The results showed that cell death after LPS and ATP stimulation is not limited to pyroptosis and that apoptosis and necrotic apoptosis can also occur, helping researchers better understand cell death after LPS and ATP stimulation and choose a better experimental method.

作者聚焦:THP-1 巨噬细胞对 LPS/ATP 的反应 — 揭示细胞焦亡、细胞凋亡和坏死性凋亡谱

This protocol is based on LPS and ATP-induced death of PMA-differentiated THP-1 macrophages. We use flow cytometry to analyze Annexin V and 7-AAD double staining to detect cell death, using the whole cell and employing scanning electron microscopy to observe the cell membrane morphology.

LPS和ATP诱导的PMA分化THP-1巨噬细胞死亡及其验证

Cell death is a fundamental process in all living organisms. The protocol establishes a lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced ...

饱和脂肪酸诱导神经酰胺相关巨噬细胞死亡

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受肥胖相关炎症组织的巨噬细胞的分离、鉴定和纯化

脂质囊泡介导的亲和层析法，使用磁性细胞分选（LIMACS）：一种新的方法来分析蛋白质 - 脂质相互作用

小鼠骨髓源性巨噬细胞 Inflammasome 活化和 Pyroptotic 细胞死亡的检测

巨噬细胞吞噬胸腺细胞吞噬的实验分析

分化肝细胞中的血管性脂细胞病的诱导和特征

的细胞内信号与相邻小区发生细胞凋亡通过互动活细胞诱导活动标识

牛肝细胞中脂滴大小和融合的评估

牛肝细胞中脂滴大小和融合的评估

牛肝细胞中脂滴大小和融合的评估

LPS和ATP诱导的PMA分化THP-1巨噬细胞死亡及其验证