在HCC4017和HBEC30KT细胞系被好心医生约翰·明纳的实验室提供。这项工作是由塞西尔H.和艾达绿色基金李章博士的支持。

注意：当放射性物质的工作，采取适当的预防措施，以避免实验者和周围环境的污染。处理掉所有废物以下本地辐射安全指引。 1.准备细胞<ol><li>种子细胞3.5厘米板，使得所述汇合上测定当天达到80％-90％。 <ol><li>需要注意的是接种汇合为细胞取决于细胞类型和它们的生长速率。当用试剂为一定天数的治疗的细胞，种子细胞，使该汇合是80％-90％的亚铁血红素测量的一天。如果从3.5厘米板获得的细胞的数量不足，则使用6厘米板用放射性的ALA相同量中的下一个步骤。 注意：使用单独的板的建议，因为它更容易处理各个板。 </li></ol></li><li>血红素测量前一天，加0.1-0.3微居里[14 C] 5-ALA和ALA冷达成最后的Concentration的20μM的总的ALA到每个培养皿中的工作区适合与放射性材料的工作，并把板放回孵化器。理想的情况下，孵育用放射性ALA 16小时。 注意：放射性标记的5-ALA需要可能的细胞系之间变化。至少100每分钟（CPM）一种放射性计数，需要尽量减少与计数相关联的错误。最好是确定[14℃] 5-ALA的需要对所研究的细胞系的最低量。对于大多数实验0.1-0.3微居里足以获得良好的测量结果。加入冷的ALA是可选的。 </li></ol> 2.提取血红素<ol><li>放置细胞培养皿在冰上，并将其送往该区域适合放射性工作。 <ol><li>执行整个萃取和蒸发过程中的防爆罩。因为存储甲醚发生爆炸，使用小瓶子乙醚和蒸发任何剩余的液体，不要储存乙醚开口瓶中超过一个月。不要使用丙酮靠近明火和加热器，因为它是高度易燃。商店丙酮的试剂玻璃瓶，因为它溶解组织培养塑料。 </li></ol></li><li>抽吸掉使用移液管的介质。用1ml 1×冷PBS洗涤细胞一次。关闭吸PBS。 </li><li>加入1毫升1×冷PBS到板和收集细胞在用橡皮板的底部。从各板传送所收集的细胞进行标记的预冷2毫升管。收集所有细胞的2ml管。 注：使用新的橡皮每个板各板刮细胞。对于每块板，你会需要四个2ml管，1.5ml试管和闪烁瓶中。 </li><li>自旋以15,000 xg离心1分钟，在4℃。 </li><li>取出PBS中使用吸液管，给短的自旋和除去残留的PBS中。重悬的细胞在100μl1×PBS中。涡旋重悬细胞，并保持在冰上。 </li><li>就拿10＃956;升从步骤5和转移到1.5ml微量离心管中并储存在冰上以测量蛋白质浓度。 注：细胞裂解缓冲液应加入到细胞中，并保持在冰上存货来测量蛋白质浓度。 </li><li>自旋从步骤5其余90微升在5000×g离心30秒，在4℃;完全用200μl枪头取出PBS。 </li><li>加入300微升血红素提取缓冲液（见材料清单），以每管。然后涡旋15秒以混合雪藏了1分钟，重复此3倍。 <ol><li>添加血红素提取缓冲液（HEB）和涡管迅速重悬沉淀，做只有一个或两个管的时间，因为粒料应迅速再悬浮而不会留在HEB太久。一旦HEB被添加到所有的管子和沉淀重悬然后按照15秒的涡流和1分钟在冰上循环如在步骤8.注意粒料可能不会完全进入HEB如果颗粒被留在HEB缓冲器为一再时间，不会很快重悬。 </li></ol></li><li>添加1.2毫升乙醚到每个管，涡旋30秒。自旋以15,000×g离心5分钟，在4℃。 注：乙醚快用完了枪头。为了控制此，吸管乙醚上下一次或两次，这样做有助于保持在吸移管的乙醚。这是一个新的枪头是用来每次重复。 </li><li>用1ml移液器转移顶部（醚）相到新的离心管中。加入0.5毫升2N盐酸，涡旋混合和自旋如步骤9。 注意：这是很难看到醚和HCl相之间的分离。因此，在实验过程中被使用，足以给它一个淡蓝色的颜色在2当量盐酸溶液中添加少量的锥虫蓝的。这将有助于区分这两个阶段。下层相将是蓝色和上部醚相将是无色的。上层无色醚相转移到新的试管，弃去下部的HCl（蓝色）相。 </li><li>重复步骤两名10更多次，以用2当量盐酸洗涤乙醚相。只有顶部醚相转移到新管中每个重复期间，丢弃下层盐酸相。 </li><li>第三次洗涤用HCl后，顶部相用1ml移液器转移到闪烁瓶中。由通过保持样品中的化学罩O / N蒸发乙醚干燥样品。 </li></ol> 3.测量放射性<ol><li>第二天，从步骤2.12加5毫升的闪烁流体向干燥的样品。 </li><li>摇匀混合。通过使用闪烁计数器测量放射性。 </li></ol> 4.计算<ol><li>从步骤2.6用CelLytic M缓冲等量裂解的细胞（见材料列表）和自旋以14000×g离心5分钟，在4℃。 </li><li>取上清液的等分试样，并使用BCA蛋白测定试剂盒测定蛋白质浓度。 蛋白以mg（TP）的合计量=（90微升*浓蛋白在81克/微升）/ 1000 血红素的合成水平（放射性/ TP）=蛋白质皮摩尔/毫克。 </li></ol>

我们什么都没有透露。

血红素起着经由呼吸26在细胞能量的产生的关键作用。改变血红素代谢是已知的各种疾病，包括癌症28,41相关联。血红素合成的抑制已知会导致细胞周期阻滞和凋亡的Hela细胞26,41。它已经表明，高血红素合成水平与肺癌细胞28的进展有关。因此，这将是非常重要的测量在不同条件下的细胞血红素生物合成的水平。这里讨论不量化血红素的总量因此该方法，但它不提?...

血红素，亚铁离子，原卟啉IX的络合物是中央分子用于运输和利用在几乎所有的活生物1-3氧。血红素的独特结构使其能够用作双原子气体和电子的载流子，以及执行各种其它功能1-5。例如，血红素结合氧血红蛋白和肌红蛋白对氧6,7的传输和存储。它也可以作为在细胞色素电子载体呼吸期间和充当用于通过细胞色素P450酶8,9-催化氧化还原反应的电子供体。之一的血红素的最显著特征是，它可以在细胞和分子过程，如基因转录，蛋白合成和微RNA的生物发生4发挥调节作用。例如，它通过控制哺乳动物转录阻遏BACH1的活性和哺乳动物核REC影响许多基因的转录eptor REV-erbα10-15。血红素调节血红素活化蛋白（HAP）1，它起着参与呼吸和控制氧化损伤的基因的活化中起重要作用，响应于血红素或氧气16的激活。血红素也调节基因转录在通 ​​过神经生长因子（NGF）信令3,17-20神经元细胞。它还通过调节血红素调节eIF2α的激酶（HRI）21-24活性调节蛋白质合成在哺乳动物红系细胞。此外，血红素影响关键信号传导蛋白如酪氨酸激酶Jak2的和Src的，这对于适当的细胞功能和细胞生长4,20,25必需的活性。结果发现，在HeLa细胞中的血红素抑制导致细胞周期阻滞与衰老和凋亡26相关的标记物和活化。既血红素不足或血红素水平增加都与人类27严重的健康影响有关。最近的一个分子第二流行病学研究显示高血红素摄入正相关和疾病，如2型糖尿病，冠状动脉心脏疾病和多种癌症，包括肺癌，结肠直肠癌和胰腺癌27,28的风险增加。使用配对正常和癌症肺细胞作者的实验室已经发现，癌细胞已经耗氧量增加，血红素合成和参与血红素摄取和利用氧的蛋白质28的水平。有趣的是，抑制血红素合成减少耗氧量，增殖，迁移和集落形成的癌细胞28。因此，内源性血红素水平波动起着分子和细胞过程3,4,28,29的调节中起重要作用。 在哺乳动物中，血红素的生物合成发生在八个步骤，涉及位于线粒体和胞液4（ 图1）的酶。血红素生物合成论文中线粒体的基质开始与甘氨酸和琥珀酰辅酶A的缩合，以形成5-氨基乙酰丙酸（5-ALA）的通过ALA合成酶（ALAS）4,31催化。这是速率限制步骤中nonerythroid细胞血红素生物合成。 5-ALA然后出口出来到接下来的四个步骤发生，以形成粪卟啉原III（CPgenIII），然后将其导入回线粒体，在那里它被转换成原卟啉IX（PPIX）的胞质溶胶中。最后，铁的一个分子掺入到原卟啉IX（PPIX）以产生血红素，通过铁螯合（FECH）2,4-催化的反应。 血红素生物合成的水平主要取决于ALAS酶被紧紧通过细胞内的铁和血红素4控制的水平。血红素的生物合成可受遗传缺陷，某些矿物质和维生素（ 例如，核黄素，锌），暴露于毒素（ 例如，铝，铅的可用性），某些类固醇（缺氧的，发烧和等级，例如雌激素）32-35。血红素合成的电平被改变的各种疾病状况。血红素下降合成可引起贫血和神经系统疾病3,36。可替换地，增加的血红素生物合成起着某些癌症28,37的发展中起重要作用。血红素已被证明是用于哺乳动物脂肪，红系和神经元细胞4,38-41的生长，分化和存活的关键。例如，血红素缺乏导致通过谷氨酸NMDA（N-甲基-D-天冬氨酸）受体17的抑制轴突损伤在原代小鼠皮质神经元。此外，抑制血红素合成引起程序性细胞死亡的上皮宫颈癌HeLa细胞26,41。因此，测量在不同条件下在各种细胞血红素生物合成水平是研究病因和progressi重要对许多疾病的。 在这里，我们描述了一种快速，灵敏的方法，使用[4- 14 C〕-5- aminolevulic酸来测量细胞内血红素合成的水平。这是一种替代方法，使用55 Fe或59的Fe的其他方法。我们喜欢使用14 C，因为它的辐射非常微弱。相反，需要用铁同位素工作有力的保障。此外，这种方法的目的是测量并以快速的方式在不同的细胞进行比较并行血红素合成。为了测量绝对血红素水平，人们可以使用的涉及使用的HPLC 42,43的先前建立的方法。

<table><tbody><tr><td>Acetone</td><td>Sigma</td><td>650501</td><td></td></tr><tr><td>Diethy ether</td><td>Sigma</td><td>296082</td><td></td></tr><tr><td>HCl (Hydrochloric acid)</td><td>Fisher</td><td>A481-212</td><td></td></tr><tr><td>Liquid Scintillation cocktail&amp;nbsp;</td><td>MP Biomedicals</td><td>882470</td><td></td></tr><tr><td>Trypan blue</td><td>Gibco</td><td>15250</td><td></td></tr><tr><td>Radiolabeled 4-&lt;sup&gt;14&lt;/sup&gt;C aminolevulinic acid</td><td>Perkin-Elmer life sciences</td><td></td><td>Store at -80 &amp;deg;C</td></tr><tr><td>CelLytic M</td><td>Sigma</td><td>C2978</td><td>Mammalian cell lysis reagent</td></tr><tr><td>Pierce BCA Protein Assay Kit&amp;nbsp;</td><td>Thermo Scientific</td><td>23227</td><td></td></tr><tr><td>&lt;strong&gt;Specific reagent&lt;/strong&gt;</td><td>&lt;strong&gt;Component&lt;/strong&gt;</td><td>&lt;strong&gt;Dispense&lt;/strong&gt;</td><td></td></tr><tr><td>Heme extraction buffer:&lt;br /&gt;Acetone:HCl:Water (25:1.3:5)</td><td>Acetone&lt;br /&gt; Concentrated HCl&lt;br /&gt;Water</td><td>25 ml&lt;br /&gt;1.3 ml&lt;br /&gt;5 ml</td><td></td></tr></tbody></table>

measurement of heme synthesis levels in mammalian cells

血红素作为辅基为多种已知作为血红素蛋白，例如血红蛋白，肌红蛋白和细胞色素蛋白。它参与各种分子和细胞过程，如基因转录，翻译，细胞分化和细胞增殖。血红素的生物合成水平在不同组织和细胞类型而变化，并改变在疾病状况如贫血，神经病变和癌症。这种技术使用[4- 14 C] 5-氨基乙酰丙酸（[14 C] 5-ALA），早期前体中的血红素生物合成途径来测量哺乳动物细胞血红素合成的级别中的一个。该测定涉及细胞与[14 C] 5-ALA进行萃取血红素结合到血红素的放射性的和测量的孵化。这个过程是准确，快速。该方法测量血红素生物合成的相对水平，而不是总血红素含量。为了证明使用该TECHN的神游血红素生物合成的水平测定几种哺乳动物细胞系。

该方法是用来比较在正常（HBEC30KT）血红素合成的水平与癌（HCC4017）肺细胞。 图2示出了血红素合成中的癌细胞（HCC4017）比正常肺细胞（HBEC30KT）的更高的水平。血红素合成的水平，也测量在正常细胞和癌细胞中的线粒体解偶联剂羰氰-3-氯苯（CCCP）的存在。用10微米的CCCP的血红素合成水平测量之前处理细胞24小时。正如所料，血红素合成的水平（ 图2）中的CCCP的在正常和?...

Watch this Scientific Journal Video about Measurement of Heme Synthesis Levels in Mammalian Cells at JoVE.com

Measurement of Heme Synthesis Levels in Mammalian Cells

Altered intracellular heme levels are associated with common diseases such as cancer. Thus, there is a need to measure heme biosynthesis levels in diverse cells. The goal of this protocol is to provide a fast and sensitive method to measure and compare the levels of heme synthesis in different cells.

中血红素的合成水平在哺乳动物细胞中测量

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in ...

measurement-of-heme-synthesis-levels-in-mammalian-cells

Research

JoVE Journal

Biology

12.0K 次观看.  University of Texas at Dallas. Altered intracellular heme levels are associated with common diseases such as cancer. Thus, there is a need to measure heme biosynthesis levels in diverse cells. The goal of this protocol is to provide a fast and sensitive method to measure and compare the levels of heme synthesis in different cells.

视频: Measurement of Heme Synthesis Levels in Mammalian Cells

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties of the materials were investigated. We used a one pot sol-gel approach to intercalate gold nano particles in the walls of mesoporous silica. To start with the synthesis, P123 was used as template to form micelles. Then TESPTS was used as a surface modification agent to intercalate gold nano particles. Following this process, TEOS was added in as a silica source which underwent a polymerization process in acid environment. After hydrothermal processing and calcination, the final product was acquired. Several techniques were utilized to characterize the porosity, morphology and structure of the gold intercalated mesoporous silica. The results showed a stable structure of mesoporous silica after gold intercalation. Through the oxidation of benzyl alcohol as a benchmark reaction, the GMS materials showed high selectivity and recyclability.

Here, we present a protocol with a sol-gel process to synthesize gold intercalated in the walls of mesoporous materials (GMS), which is confirmed to possess a mesoporous matrix with gold intercalated in the walls imparting great stability and recyclability.

合成和金插在介孔二氧化硅的墙壁催化性能

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties ...

科研

化学

Biochemical Measurement of Neonatal Hypoxia

Neonatal hypoxia ischemia is characterized by inadequate blood perfusion of a tissue or a systemic lack of oxygen. This condition is thought to cause/exacerbate well documented neonatal disorders including neurological impairment 1-3. Decreased adenosine triphosphate production occurs due to a lack of oxidative phosphorylation. To compensate for this energy deprived state molecules containing high energy phosphate bonds are degraded 2. This leads to increased levels of adenosine which is subsequently degraded to inosine, hypoxanthine, xanthine, and finally to uric acid. The final two steps in this degradation process are performed by xanthine oxidoreductase. This enzyme exists in the form of xanthine dehydrogenase under normoxic conditions but is converted to xanthine oxidase (XO) under hypoxia-reperfusion circumstances 4, 5. Unlike xanthine dehydrogenase, XO generates hydrogen peroxide as a byproduct of purine degradation 4, 6. This hydrogen peroxide in combination with other reactive oxygen species (ROS) produced during hypoxia, oxidizes uric acid to form allantoin and reacts with lipid membranes to generate malondialdehyde (MDA) 7-9. Most mammals, humans exempted, possess the enzyme uricase, which converts uric acid to allantoin. In humans, however, allantoin can only be formed by ROS-mediated oxidation of uric acid. Because of this, allantoin is considered to be a marker of oxidative stress in humans, but not in the mammals that have uricase.
We describe methods employing high pressure liquid chromatography (HPLC) and gas chromatography mass spectrometry (GCMS) to measure biochemical markers of neonatal hypoxia ischemia. Human blood is used for most tests. Animal blood may also be used while recognizing the potential for uricase-generated allantoin. Purine metabolites were linked to hypoxia as early as 1963 and the reliability of hypoxanthine, xanthine, and uric acid as biochemical indicators of neonatal hypoxia was validated by several investigators 10-13. The HPLC method used for the quantification of purine compounds is fast, reliable, and reproducible. The GC/MS method used for the quantification of allantoin, a relatively new marker of oxidative stress, was adapted from Gruber et al 7. This method avoids certain artifacts and requires low volumes of sample. Methods used for synthesis of MMDA were described elsewhere 14, 15. GC/MS based quantification of MDA was adapted from Paroni et al. and Cighetti et al. 16, 17. Xanthine oxidase activity was measured by HPLC by quantifying the conversion of pterin to isoxanthopterin 18. This approach proved to be sufficiently sensitive and reproducible.

A method is described to measure biochemical markers of neonatal hypoxia-ischemia. The approach utilizes high pressure liquid chromatography (HPLC) and Gas Chromatography Mass Spectrometry (GC/MS).

新生儿缺氧的生化测量

Neonatal hypoxia ischemia is characterized by inadequate blood perfusion of a tissue or a systemic lack of oxygen. This condition is thought to ...

医学

Quantification of Coenzyme A in Cells and Tissues

Emerging research has revealed that the cellular coenzyme A (CoA) supply can become limiting with a detrimental impact on growth, metabolism and survival. Measurement of cellular CoA is a challenge due to its relatively low abundance and the dynamic conversion of free CoA to CoA thioesters that, in turn, participate in numerous metabolic reactions. A method is described that navigates through potential pitfalls during sample preparation to yield an assay with a broad linear range of detection that is suitable for use in many biomedical laboratories.

This method describes sample preparation from cultured cells and animal tissues, extraction and derivatization of coenzyme A in the samples, followed by high pressure liquid chromatography for purification and quantification of the derivatized coenzyme A by absorbance or fluorescence detection.

细胞和组织中辅酶A的定量

Emerging research has revealed that the cellular coenzyme A (CoA) supply can become limiting with a detrimental impact on growth, metabolism and survival. ...

生物化学

Measurement of Fatty Acid &#946;-Oxidation in a Suspension of Freshly Isolated Mouse Hepatocytes

Fatty acid &#946;-oxidation is a key metabolic pathway to meet the energy demands of the liver and provide substrates and cofactors for additional processes, such as ketogenesis and gluconeogenesis, which are essential to maintain whole-body glucose homeostasis and support extra-hepatic organ function in the fasted state. Fatty acid &#946;-oxidation occurs within the mitochondria and peroxisomes and is regulated through multiple mechanisms, including the uptake and activation of fatty acids, enzyme expression levels, and availability of cofactors such as coenzyme A and NAD+. In assays that measure fatty acid &#946;-oxidation in liver homogenates, cell lysis and the common addition of supraphysiological levels of cofactors mask the effects of these regulatory mechanisms. Furthermore, the integrity of the organelles in the homogenates is hard to control and can vary significantly between preparations. The measurement of fatty acid &#946;-oxidation in intact primary hepatocytes overcomes the above pitfalls. This protocol describes a method for the measurement of fatty acid &#946;-oxidation in a suspension of freshly isolated primary mouse hepatocytes incubated with 14C-labeled palmitic acid. By avoiding hours to days of culture, this method has the advantage of better preserving the protein expression levels and metabolic pathway activity of the original liver, including the activation of fatty acid &#946;-oxidation observed in hepatocytes isolated from fasted mice compared to fed mice.

Fatty acid &#946;-oxidation is an essential metabolic pathway responsible for generating energy in many different cell types, including hepatocytes. Here, we describe a method to measure fatty acid &#946;-oxidation in freshly isolated primary hepatocytes using 14C-labeled palmitic acid.

测量新鲜分离的小鼠肝细胞悬浮液中的脂肪酸β氧化

Fatty acid &#946;-oxidation is a key metabolic pathway to meet the energy demands of the liver and provide substrates and cofactors for additional ...

Induction of an Inflammatory Response in Primary Hepatocyte Cultures from Mice

The liver plays a decisive role in the regulation of systemic inflammation. In chronic kidney disease in particular, the liver reacts in response to the uremic milieu, oxidative stress, endotoxemia and the decreased clearance of circulating proinflammatory cytokines by producing a large number of acute-phase reactants. Experimental tools to study inflammation and the underlying role of hepatocytes are crucial to understand the regulation and contribution of hepatic cytokines to a systemic acute phase response and a prolonged pro-inflammatory scenario, especially in an intricate setting such as chronic kidney disease. Since studying complex mechanisms of inflammation in vivo remains challenging, resource-intensive and usually requires the usage of transgenic animals, primary isolated hepatocytes provide a robust tool to gain mechanistic insights into the hepatic acute-phase response. Since this in vitro technique features moderate costs, high reproducibility and common technical knowledge, primary isolated hepatocytes can also be easily used as a screening approach. Here, we describe an enzymatic-based method to isolate primary murine hepatocytes, and we describe the assessment of an inflammatory response in these cells using ELISA and quantitative real-time PCR.

Here, we show an enzymatic approach to isolate primary hepatocytes from adult mice, and we describe the quantification of an inflammatory response using ELISA and real-time PCR.

从小鼠在原代肝细胞培养物的炎性反应的诱导

The liver plays a decisive role in the regulation of systemic inflammation. In chronic kidney disease in particular, the liver reacts in response to the ...

免疫与感染

Robust Generation of Hepatocyte-like Cells from Human Embryonic Stem Cell Populations

Despite progress in modelling human drug toxicity, many compounds fail during clinical trials due to unpredicted side effects. The cost of clinical studies are substantial, therefore it is essential that more predictive toxicology screens are developed and deployed early on in drug development (Greenhough et al 2010). Human hepatocytes represent the current gold standard model for evaluating drug toxicity, but are a limited resource that exhibit variable function. Therefore, the use of immortalised cell lines and animal tissue models are routinely employed due to their abundance. While both sources are informative, they are limited by poor function, species variability and/or instability in culture (Dalgetty et al 2009). Pluripotent stem cells (PSCs) are an attractive alternative source of human hepatocyte like cells (HLCs) (Medine et al 2010). PSCs are capable of self renewal and differentiation to all somatic cell types found in the adult and thereby represent a potentially inexhaustible source of differentiated cells. We have developed a procedure that is simple, highly efficient, amenable to automation and yields functional human HLCs (Hay et al 2008 ; Fletcher et al 2008 ; Hannoun et al 2010 ; Payne et al 2011 and Hay et al 2011). We believe our technology will lead to the scalable production of HLCs for drug discovery, disease modeling, the construction of extra-corporeal devices and possibly cell based transplantation therapies.

This article will focus on the generation of human hepatic endoderm from human embryonic stem cell populations.

肝细胞样细胞从人类胚胎干细胞群的鲁棒代

Despite progress in modelling human drug toxicity, many compounds fail during clinical trials due to unpredicted side effects. The cost of clinical ...

生物学

From Cells to Cell-Free Protein Synthesis within 24 Hours Using Cell-Free Autoinduction Workflow

Cell-free protein synthesis (CFPS) has grown as a biotechnology platform that captures transcription and translation machinery in vitro. Numerous developments have made the CFPS platform more accessible to new users and have expanded the range of applications. For lysate based CFPS systems, cell extracts can be generated from a variety of organisms, harnessing the unique biochemistry of that host to augment protein synthesis. Within the last 20 years, Escherichia coli (E. coli) has become one of the most widely used organisms for supporting CFPS due to its affordability and versatility. Despite numerous key advances, the workflow for E. coli cell extract preparation has remained a key bottleneck for new users to implement CFPS for their applications. The extract preparation workflow is time-intensive and requires technical expertise to achieve reproducible results. To overcome these barriers, we previously reported the development of a 24 hour cell-free autoinduction (CFAI) workflow that reduces user input and technical expertise required. The CFAI workflow minimizes the labor and technical skill required to generate cell extracts while also increasing the total quantities of cell extracts obtained. Here we describe that workflow in a step-by-step manner to improve access and support the broad implementation of E. coli based CFPS.

This work describes the preparation of cell extract from Escherichia coli (E. coli) followed by cell-free protein synthesis (CFPS) reactions in under 24 hours. Explanation of the cell-free autoinduction (CFAI) protocol details improvements made to reduce researcher oversight and increase quantities of cell extract obtained.

使用无细胞自动诱导工作流程在24小时内从细胞到无细胞蛋白质合成

Cell-free protein synthesis (CFPS) has grown as a biotechnology platform that captures transcription and translation machinery in vitro. Numerous ...

生物工程

Measurement of Tissue Non-Heme Iron Content using a Bathophenanthroline-Based Colorimetric Assay

Iron is an essential micronutrient. Both iron overload and deficiency are highly detrimental to humans, and tissue iron levels are finely regulated. The use of experimental animal models of iron overload or deficiency has been instrumental to advance knowledge of the mechanisms involved in the systemic and cellular regulation of iron homeostasis. The measurement of total iron levels in animal tissues is commonly performed with atomic absorption spectroscopy or with a colorimetric assay based on the reaction of non-heme iron with a bathophenanthroline reagent. For many years, the colorimetric assay has been used for the measurement of the non-heme iron content in a wide range of animal tissues. Unlike atomic absorption spectroscopy, it excludes the contribution of heme iron derived from hemoglobin contained in red blood cells. Moreover, it does not require sophisticated analytical skills or highly expensive equipment, and can thus be easily implemented in most laboratories. Finally, the colorimetric assay can be either cuvette-based or adapted to a microplate format, allowing higher sample throughput. The present work provides a well-established protocol that is suited for the detection of alterations in tissue iron levels in a variety of experimental animal models of iron overload or iron deficiency.

Here, a protocol for the measurement of the non-heme iron content in animal tissues is provided, using a simple, well-established colorimetric assay that can be easily implemented in most laboratories.

使用基于菲咯啉的比色法测量组织非血红素铁含量

Iron is an essential micronutrient. Both iron overload and deficiency are highly detrimental to humans, and tissue iron levels are finely regulated. The ...

使用流式细胞术进行小鼠脑组蛋白修饰定量

Quantification of Global Histone Post Translational Modifications Using Intranuclear Flow Cytometry in Isolated Mouse Brain Microglia

Gene expression control occurs partially by modifications in chromatin structure, including the addition and removal of posttranslational modifications to histone tails. Histone post-translational modifications (HPTMs) can either facilitate gene expression or repression. For example, acetylation of histone tail lysine residues neutralizes the positive charge and reduces interactions between the tail and negatively charged DNA. The decrease in histone tail-DNA interactions results in increased accessibility of the underlying DNA, allowing for increased transcription factor access. The acetylation mark also serves as a recognition site for bromodomain-containing transcriptional activators, together resulting in enhanced gene expression. Histone marks can be dynamically regulated during cell differentiation and in response to different cellular environments and stimuli. While next-generation sequencing approaches have begun to characterize genomic locations for individual histone modifications, only one modification can be examined concurrently. Given that there are hundreds of different HPTMs, we have developed a high throughput, quantitative measure of global HPTMs that can be used to screen histone modifications prior to conducting more extensive genome sequencing approaches. This protocol describes a flow cytometry-based method to detect global HPTMs and can be conducted using cells in culture or isolated cells from in vivo tissues. We present example data from isolated mouse brain microglia to demonstrate the sensitivity of the assay to detect global shifts in HPTMs in response to a bacteria-derived immune stimulus (lipopolysaccharide). This protocol allows for the rapid and quantitative assessment of HPTMs and can be applied to any transcriptional or epigenetic regulator that can be detected by an antibody.

作者聚焦:基因表达调控研究的增强

This work describes a protocol for the quantification of global histone modifications using intranuclear flow cytometry in isolated brain microglia. The work also contains the microglia isolation protocol that was used for data collection.

使用核内流式细胞术定量分离小鼠脑小胶质细胞中的整体组蛋白翻译后修饰

Gene expression control occurs partially by modifications in chromatin structure, including the addition and removal of posttranslational modifications to ...

中血红素的合成水平在哺乳动物细胞中测量

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使用核内流式细胞术定量分离小鼠脑小胶质细胞中的整体组蛋白翻译后修饰

使用核内流式细胞术定量分离小鼠脑小胶质细胞中的整体组蛋白翻译后修饰