我々は、使用されたマウスの脊髄の組織サンプルを提供するためのミネソタ大学の李研究室に感謝したいと思います。この作品は、MBにMBに、ランディシェーバーがん研究とコミュニティ基金MBにミネソタ卵巣癌アライアンス（MOCA）による国防総省の卵巣癌研究プログラム（OCRP）OC093424によってサポートされていました。資金提供者は、研究デザイン、データ収集と分析、公開することを決定または原稿の準備で何の役割も持っていません。

1.溶解緩衝液の調製<ol><li> 2 Mのストック溶液を作るために、脱イオン（DI）水にスクロースを溶解します。 0.22μmのポリフッ化ビニリデン（PVDF）フィルタを駆動し、真空を用いて、スクロースの2M溶液をフィルタリングします。 </li><li>嫌気条件下で500 mMのストック溶液およびストアを作成するためにDI水にジチオスレイトール（DTT）を溶解します。 100mMのストック溶液を作製するためにDI水に塩化マグネシウム（MgCl 2を） を溶解します。 50mMのストック溶液を作製するためにアデノシン三リン酸（ATP）DI水中の二ナトリウム水和物を溶解します。 </li><li> DI水中のトリズマ塩酸塩を溶解し、水酸化ナトリウム（NaOH）を用いてpHを調整することにより、pH7.4のTris溶液を作ります。 </li><li> 250 mMの、1mMの、5 ​​mMとのMgCl 2濃度は、1mMとATP濃度及び50mMのトリス濃度のDTT濃度のスクロース濃度で溶解緩衝液を作製するためにDI水に原液の部分を組み合わせます。例えば、トリス、50の535.3μLを混ぜます溶解緩衝液の10ミリリットルを作るためにMgCl 2を0μlを、スクロースの1.25ミリリットル、DTT20μlの、ATPを200μlとDI水の7.4947ミリリットル。これは、約20の実験のために使用することができます。 </li></ol>実験2.細胞を培養します<ol><li> 50mlコニカルチューブにDMEM + 10％ウシ胎児血清（FBS）の30ミリリットルを小分けして、メディアを作成します。 </li><li>ぬるま湯を入れた小さなビーカーに液体窒素保存から冷凍M17またはヒーラ細胞を転送します。 </li><li> 50mlコニカルチューブに細胞を移します。まず、セ​​ルバイアルに、いくつかのメディアを追加。その後、解凍の5秒以内に再懸濁した細胞を移します。 </li><li>細胞ペレットを得るために、5分間、450×gで細胞懸濁液を遠心。 T75フラスコに培地20mlのを追加します。 </li><li>吸引を用いて細胞からメディアを取り出します。細胞ペレットを再懸濁に新鮮な培地の5ミリリットルを追加します。 </li><li> T75フラスコ中の培地20mlに5ミリリットルの細胞懸濁液を移し、37℃でインキュベートします。 CH3日ごとにメディアをANGE。 </li></ol> 3.細胞の回収<ol><li>細胞に触れないように注意しながら、吸引を介してメディアを取り出します。 </li><li>リン酸緩衝生理食塩水（PBS）5mlで細胞を洗浄します。吸引を使用してPBSを削除します。 </li><li> T75フラスコにトリプシン - エチレンジアミン四酢酸（EDTA）を3mlを加え、3分間37℃でインキュベートします。 </li><li>フラスコに新鮮な培地の6ミリリットルを追加し、細胞を再懸濁。 </li><li> 5分間290×gで15ミリリットルコニカルチューブと遠心分離機にサスペンションを転送します。 </li><li>上清を除去し、5mlのPBSを追加します。静かにペレットを破壊するためにチューブの底をタップします。 5分間290×gで遠心分離します。 </li><li>繰り返し手順3.6三回。 </li><li> PBSを除去し、新鮮な1mlのPBSで細胞を懸濁します。エッペンドルフチュー​​ブ（1.5ミリリットル）に移します。 5分間290×gでスピン。 </li></ol> 4.細胞溶解<ol><li>ピペットANを用いてペレットのおおよその体積を測定大量にガラスビーズを秤量dは1：1：1の体積比。溶解緩衝液中のペレットの2倍容量を追加します。 注意：ガラスビーズを追加する前にバッファを追加します。 </li><li>を溶解低温室にボルテックスすることによって4℃で30分間攪拌最大でエッペンドルフチュー​​ブ中の細胞。 </li><li>ビーズを解決する30秒200×gで遠心分離する簡単。上清を収集します。 </li><li>上清を前のように、ガラスビーズの同じ量を加えます。 </li><li> 4℃で30分間、最大攪拌で再びボルテックス。 </li><li>ガラスビーズを解決する30秒200×gで遠心分離する簡単。上清を収集します。 </li><li>核、膜および破壊されていない細胞を除去するために5分間、5030×gで遠心分離します。細胞溶解物である上清を、収集します。 </li></ol> 5.組織の均質化<ol><li>溶解バッファーにマウス脊髄組織の9溶液：1の体積質量を行います。 注：このメソッドは、異なるさまざまなに適用可能ですENT組織サンプル。 </li><li>残っていないチャンクが存在しないことを確実にするために30秒間均質化にレベル2の設定を使用して組織を均質化します。 </li><li>核、膜および破壊されていない細胞を除去するために、3分間5030×gでスピンダウン。 </li><li>溶解液である上清を、収集します。 </li></ol> 6.サンプルの誘導体化<ol><li>ピアースBCAタンパク質アッセイキットプロトコルによって指定されるように、比色、96ウェルプレートリーダーを使用して組織溶解物のタンパク質濃度を決定するために、96ウェルプレート分析でビシンコニン酸（BCA）を実行します。 </li><li>脱イオン（DI）水を用いて50μlに合計20μgのタンパク質に対応するアリコートを持参してください。 </li><li>溶液に、HA-UB-ビニルスルホン（VS）の1.35μMの2μlを添加して、37℃で1時間インキュベートします。これは、最終反応混合物中のプローブの50 nmの溶解物20μgの結果。これは、機能のDUBのタグ付けを確実にするために、大モル過剰です。 </li><li>私95℃で5分間のレムリ試料緩衝液中でサンプルをncubate。 52μlの反応体積の使用2×試料緩衝液26μlを、4×試料緩衝液13μlあるいは6×サンプル緩衝液8.87μlのため。 </li><li>ゲルをロードする前に、氷上で冷却します。 </li></ol> 7.ウエスタンブロット<ol><li>調製した試料の40μlの12ウェル4〜20％トリス - グリシンゲルをロード</li><li>イオンフロントが底に到達するまで、95 Vでゲルを実行します。 </li><li>ポリフッ化ビニリデン（PVDF）膜上のゲルの一晩の転送を行います。 </li><li>アミドブラック染色で膜をインキュベートし、各レーン中のタンパク質の量を示す画像を得ることがmembaneをスキャンします。 </li><li>膜を脱色し、ブロックする1時間PBS中の5％ミルクでインキュベートします。 </li><li> 1の濃度の一次抗HA抗体で膜をインキュベートする：PBS中の5％ミルク10,000のいずれかを4℃で一晩または室温で4時間。 </li><li> fは3回の洗浄を行いますまたは0.1％のTween-20洗剤でPBS中で5分間ずつ。 </li><li> 1の濃度でマウス西洋ワサビペルオキシダーゼで膜をインキュベートする：少なくとも2時間、PBS 10,000 5％ミルク。 </li><li> 0.1％のTween-20洗剤でPBS中で5分間ずつ3回の洗浄を行います。 </li><li> PBSで5分間1回洗浄を行います。 </li><li> 10分間の化学発光検出試薬で膜をインキュベートし、化学発光検出器を用いて検出します。検出器の自動露出設定を使用してください。 </li></ol>

<ol>
	<li>Ovaa, H., Kessler, B. M., Rol&#233;n, U., Galardy, P. J., Ploegh, H. L., Masucci, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activity-+based+ubiquitin-specific+(USP)+profiling+of+virus-infected+and+malignant+human+cells.">Activity- based ubiquitin-specific (USP) profiling of virus-infected and malignant human cells.</a> Proc Natl Acad Sci USA. 101 (8), 2253-2258 (2004).</li><li>Wilkinson, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ubiquitination+and+deubiquitination:+Targeting+of+proteins+for+degradation+by+the+proteasome.">Ubiquitination and deubiquitination: Targeting of proteins for degradation by the proteasome.</a> Semin Cell Dev Biol. 11 (3), 141-148 (2000).</li><li>Ziad, M. E., Wilkinson, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+proteolysis+by+human+deubiquitinating+enzymes.">Regulation of proteolysis by human deubiquitinating enzymes.</a> Biochim Biophys Acta. 1843 (1), 114-128 (2014).</li><li>Rol&#233;n, U., 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=Activity+Profiling+of+Deubiquitinating+Enzymes+in+Cervical+Carcinoma+Biopsies+and+Cell+Lines.">Activity Profiling of Deubiquitinating Enzymes in Cervical Carcinoma Biopsies and Cell Lines.</a> Mol Carcinog. 45 (4), 260-269 (2006).</li><li>Borodovsky, A., 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=Chemistry-Based+Functional+Proteomics+Reveals+Novel+Members+of+the+Deubiquitinating+Enzyme+Family.">Chemistry-Based Functional Proteomics Reveals Novel Members of the Deubiquitinating Enzyme Family.</a> Chem Biol. 9 (10), 1149-1159 (2002).</li><li>Andersson, F. L., 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=The+effect+of+Parkinson&#8217;s-disease-associated+mutations+on+the+deubiquitinating+enzyme+UCH-L1.">The effect of Parkinson&#8217;s-disease-associated mutations on the deubiquitinating enzyme UCH-L1.</a> J Mol Biol. 407 (2), 261-272 (2011).</li><li>Poon, W. W., 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=&#946;-Amyloid+(A&#946;)+oligomers+impair+brain-derived+neurotrophic+factor+retrograde+trafficking+by+down-regulating+ubiquitin+C-terminal+hydrolase+UCH-L1.">&#946;-Amyloid (A&#946;) oligomers impair brain-derived neurotrophic factor retrograde trafficking by down-regulating ubiquitin C-terminal hydrolase UCH-L1.</a> J Biol Chem. 288 (23), 16937-16948 (2013).</li><li>Nijman, S. M., 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=The+deubiquitinating+enzyme+USP1+regulates+the+Fanconi+anemia+pathway.">The deubiquitinating enzyme USP1 regulates the Fanconi anemia pathway.</a> Mol Cell. 17 (3), 331-339 (2005).</li><li>Stevenson, L. F., Sparks, A., Allende-Vega, N., Xirodimas, D. P., Lane, D. P., Saville, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+deubiquitinating+enzyme+USP2a+regulates+the+p53+pathway+by+targeting+Mdm2.">The deubiquitinating enzyme USP2a regulates the p53 pathway by targeting Mdm2.</a> EMBO J. 26 (4), 976-986 (2007).</li><li>Coughlin, K., 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=Small-molecule+RA-9+inhibits+proteasome-associated+DUBs+and+ovarian+cancer+in+vitro+and+in+vivo+via+exacerbating+unfolded+protein+responses.">Small-molecule RA-9 inhibits proteasome-associated DUBs and ovarian cancer in vitro and in vivo via exacerbating unfolded protein responses.</a> Clin Cancer Res. 20 (12), 3174-3186 (2014).</li><li>Colla, E., 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=Endoplasmic+Reticulum+Stress+Is+Important+for+the+Manifestations+of+&#945;-Synucleinopathy+In.">Endoplasmic Reticulum Stress Is Important for the Manifestations of &#945;-Synucleinopathy In.</a> Vivo. J Neurosci. 32 (10), 3306-3320 (2012).</li></ol>

著者らは、開示することは何もありません。

ユビキチン化は、基本的な細胞活動であるので、調節機構を理解することは、疾患や病態のプロセスを発掘するための鍵である可能性があります。 HAの使用は、UB-媒介タンパク質分解を研究するための簡単​​な、しかし非常に適用可能な方法を提供し、ここで報告したUb由来の活性部位特異的プローブをタグ付け。この方法は、個別のDUBのそれぞれの研究よりも速く、安価です。 <p class=...

ユビキチン - プロテアソームシステム（UPS）は、哺乳動物細胞内の主要な分解経路の一つとして機能します。プロテアソームで分解のためにバインドされた基板は、共有結合、ユビキチン（Ubが）1のポリマーとタグ付けされています。標的基質は、分解のためのプロテアソームに入る前に、ポリユビキチンタグを削除する必要があります。脱ユビキチン化酵素として知られる酵素のクラス（のDUB）はユビキチン分子2の除去とリサイクルを担当しています。これは、セル3内の作業約100のDUBがあることがヒトゲノムから予測されています。 UB-媒介細胞プロセスを制御するのDUBのような大規模な数と、これらの酵素を研究するだけで発現レベルに関する情報を提供するmRNA技術が活性およびウェスタンブロッティングの情報を与えないので、課題を提示します。 インフルエンザ赤血球凝集素（HA）の使用は、共有結合を可能にするMOD活性部位指向プローブをUB-由来、タグ付け機能のDUBのification、したがって、ウェスタンブロット4のこれらの酵素の活性の直接可視化を提供します。プローブは、活性部位のシステイン残基5ため自殺基質として作用するC末端のチオール反応性基を有します。これらのプローブによれば、細胞の病理学的および生理学的状態の両方で、多くのDUB活性の潜在的な発現を研究することが可能です。 DUB活性の変化は、パーキンソン病、アルツハイマー病、貧血および様々な癌6-10のような病理学的条件の範囲に関与しています。この技術は、疾患の研究のための強力なツールを提供します。本論文では、ガラスビーズを用いて溶解されているHeLa細胞およびM17細胞におけるこの技術の適用を示します。さらに、我々は、マウスの脊髄組織サンプルでこのメソッドを使用する方法の概要を示します。この技術から得られた情報を識別するための出発点として使用することができ治療標的ならびに異なる疾患状態の研究のためのモデルを確立します。この技術の真の有用性は、単一のアッセイで複数のDUBに関する情報を提供する能力にあります。

<table border="0" cellpadding="0" cellspacing="0" style="width:615px;" width="615">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">PowerGen 125 ( Homogenizer)</td>
			<td style="width:113px;">Fischer Scientific</td>
			<td style="width:119px;">14-261-02P</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Vacuum-driven filters .22&#181;M&#160;</td>
			<td style="width:113px;"></td>
			<td style="width:119px;">BPV2210</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Glass beads, acid washed &#8804;106&#181;m (~140 U.S. sieve)</td>
			<td style="width:113px;">Sigma-aldrich</td>
			<td style="width:119px;">G4649-10G</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Sucrose</td>
			<td style="width:113px;">Fischer Scientific</td>
			<td style="width:119px;">S6-212</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">DL-Dithiothreitol</td>
			<td style="width:113px;">Sigma-Aldrich</td>
			<td style="width:119px;">D0632</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Magnesium Chloride</td>
			<td style="width:113px;">Sigma-Aldrich</td>
			<td style="width:119px;">M8266</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Adenosine 5&#39;-triphosphate disodium salt hydrate</td>
			<td style="width:113px;">Sigma-aldrich</td>
			<td style="width:119px;">A26209</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Trizma hydrochloride&#160;</td>
			<td style="width:113px;">Sigma-aldrich</td>
			<td style="width:119px;">T3253</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Dulbecco&#39;s Modified Eagle Medium</td>
			<td style="width:113px;">Life technologies</td>
			<td style="width:119px;">11965-092</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Phosphate Buffered Saline</td>
			<td style="width:113px;">Life technologies</td>
			<td style="width:119px;">10010-023</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Tissue culture flask 75cm2 w/ filter cup 250 ml 120/ cs</td>
			<td style="width:113px;">Cellstar</td>
			<td style="width:119px;">T-3001-2</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">0.05% Trypsin-EDTA (1X)</td>
			<td style="width:113px;">Life technologies</td>
			<td style="width:119px;">25300-054</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">HI FBS</td>
			<td style="width:113px;">Life technologies</td>
			<td style="width:119px;">16140-071</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Monoclonal Anti-HA antibody produced in mouse</td>
			<td style="width:113px;">Sigma-aldrich</td>
			<td style="width:119px;">H9658</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Ubiquitin vinyl sulfone (HA-tag)</td>
			<td style="width:113px;">Enzo Life Sciences</td>
			<td style="width:119px;">BML-UW0155-0025</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Laemmli&#39;s SDS-Sample Buffer (4X, reducing)</td>
			<td style="width:113px;">Boston BioProducts</td>
			<td style="width:119px;">BP-110R</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Pierce BCA Protein Assay Kit</td>
			<td style="width:113px;">ThermoScientific</td>
			<td align="right" style="width:119px;">23225</td>
			<td></td>
		</tr>
	</tbody>
</table>

method for measuring the activity of deubiquitinating enzymes in cell lines and tissue samples

ユビキチン - プロテアソーム系は、最近、神経変性疾患および癌を含む種々の病態に関与しています。この観点から、このシステムの調節機構を研究するための技術は、上記疾患の細胞および分子プロセスを解明するために不可欠です。本稿で概​​説した赤血球凝集素由来のユビキチンプローブの使用は、このシステムの研究のための貴重なツールとして機能します。本稿では、酵素活性を脱ユビキチン化の直接的な可視化を与えるアッセイを実行することを可能にする方法を詳述します。脱ユビキチン化酵素は、プロテアソーム分解を制御し、ユーザーが1つのアッセイで複数の酵素の活性を調査することができ、それらの活性部位での機能的相同性を共有します。溶解物を、穏やかな機械的な細胞破壊を介して得られた活性部位指向プローブと共にインキュベートします。非アクティブな酵素が結合していないままで機能的酵素は、プローブでタグ付けされています。実行で寧このアッセイは、ユーザが迅速かつ簡単な方法で活動し、複数の脱ユビキチン化酵素の潜在的な発現の両方の情報を取得します。現在の方法は、ヒト細胞における予測百脱ユビキチン化酵素のための個々の抗体を使用するよりも大幅に効率的です。

培養M17およびHeLa細胞は、プロトコル（3細胞収穫）に詳述する方法を用いて回収し、マウスの脊髄組織が得られました。細胞ペレット/脊髄組織は、試薬調製の項に記載の溶解緩衝液を用いて管に入れました。細胞ペレットをホモジナイザー（ 図1B）を用いてホモジナイズしたガラスビーズ（ 図1A）およびマウス脊髄組織サンプルを用いて溶解しました。溶解または均...

Watch this Scientific Journal Video about Method for Measuring the Activity of Deubiquitinating Enzymes in Cell Lines and Tissue Samples at JoVE.com

Method for Measuring the Activity of Deubiquitinating Enzymes in Cell Lines and Tissue Samples

現在のプロトコルは、機能的に相同脱ユビキチン化酵素の活性を測定する方法を詳述します。特殊なプローブは、共有結合酵素を変更し、検出を可能にします。この方法は、新たな治療標的を同定する可能性を保持しています。

細胞株および組織試料中の脱ユビキチン化酵素の活性を測定する方法

The ubiquitin-proteasome system has recently been implicated in various pathologies including neurodegenerative diseases and cancer. In light of this, ...

method-for-measuring-activity-deubiquitinating-enzymes-cell-lines

Research

JoVE Journal

Biology

9.5K ビュー.  University of Minnesota. 現在のプロトコルは、機能的に相同脱ユビキチン化酵素の活性を測定する方法を詳述します。特殊なプローブは、共有結合酵素を変更し、検出を可能にします。この方法は、新たな治療標的を同定する可能性を保持しています。 

ビデオ: Method for Measuring the Activity of Deubiquitinating Enzymes in Cell Lines and Tissue Samples

Actin Co-Sedimentation Assay; for the Analysis of Protein Binding to F-Actin

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates tension and helps maintains cellular shape.  Although the actin cytoskeleton is a rigid structure, it is a dynamic structure that is constantly remodeling.  A number of proteins can bind to the actin cytoskeleton.  The binding of a particular protein to F-actin is often desired to support cell biological observations or to further understand dynamic processes due to remodeling of the actin cytoskeleton. The actin co-sedimentation assay is an in vitro assay routinely used to analyze the binding of specific proteins or protein domains with F-actin.  The basic principles of the assay involve an incubation of the protein of interest (full length or domain of) with F-actin, ultracentrifugation step to pellet F-actin and analysis of the protein co-sedimenting with F-actin.  Actin co-sedimentation assays can be designed accordingly to measure actin binding affinities and in competition assays.

Proteins bind to filamentous actin (F-actin) through distinct actin binding modules. In this video we demonstrate the procedure of actin co-sedimentation, which is an in vitro assay routinely used to analyze proteins or specific domains that bind F-actin.

アクチン共沈降アッセイ、F -アクチンへの結合タンパク質の解析のための

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates ...

生物学

Quantitation of &gamma;H2AX Foci in Tissue Samples

DNA double-strand breaks (DSBs) are particularly lethal and genotoxic lesions, that can arise either by endogenous (physiological or pathological) processes or by exogenous factors, particularly ionizing radiation and radiomimetic compounds. Phosphorylation of the H2A histone variant, H2AX, at the serine-139 residue, in the highly conserved C-terminal SQEY motif, forming &gamma;H2AX, is an early response to DNA double-strand breaks1. This phosphorylation event is mediated by the phosphatidyl-inosito 3-kinase (PI3K) family of proteins, ataxia telangiectasia mutated (ATM), DNA-protein kinase catalytic subunit and ATM and RAD3-related (ATR)2. Overall, DSB induction results in the formation of discrete nuclear &gamma;H2AX foci which can be easily detected and quantitated by immunofluorescence microscopy2. Given the unique specificity and sensitivity of this marker, analysis of &gamma;H2AX foci has led to a wide range of applications in biomedical research, particularly in radiation biology and nuclear medicine. The quantitation of &gamma;H2AX foci has been most widely investigated in cell culture systems in the context of ionizing radiation-induced DSBs. Apart from cellular radiosensitivity, immunofluorescence based assays have also been used to evaluate the efficacy of radiation-modifying compounds. In addition, &gamma;H2AX has been used as a molecular marker to examine the efficacy of various DSB-inducing compounds and is recently being heralded as important marker of ageing and disease, particularly cancer3. Further, immunofluorescence-based methods have been adapted to suit detection and quantitation of &gamma;H2AX foci ex vivo and in vivo4,5. Here, we demonstrate a typical immunofluorescence method for detection and quantitation of &gamma;H2AX foci in mouse tissues.

Quantitation of &amp;#947;H2AX Foci in Tissue Samples

Quantitation of DNA double-strand breaks on the basis of &gamma;H2AX foci has become an invaluable tool, particularly in radiation biology, for the evaluation of tissue radiosensitivity and effects of radiation modifying compounds. Here we demonstrate the use of an immunofluorescence assay for quantitation of &gamma;H2AX foci in tissue samples.

組織サンプルのγH2AX病巣の定量

DNA double-strand breaks (DSBs) are particularly lethal and genotoxic lesions, that can arise either by endogenous (physiological or pathological) ...

An Assay for Measuring the Activity of Escherichia coli Inducible Lysine Decarboxyase

Escherichia coli is an enteric bacterium that is capable of growing over a wide range of pH values (pH 5 - 9)1 and, incredibly, is able to survive extreme acid stresses including passage through the mammalian stomach where the pH can fall to as low as pH 1 - 22. To enable such a broad range of acidic pH survival, E. coli possesses four different inducible amino acid decarboxylases that decarboxylate their substrate amino acids in a proton-dependent manner thus raising the internal pH. The decarboxylases include the glutamic acid decarboxylases GadA and GadB3, the arginine decarboxylase AdiA4, the lysine decarboxylase LdcI5, 6 and the ornithine decarboxylase SpeF7. All of these enzymes utilize pyridoxal-5'-phospate as a co-factor8 and function together with inner-membrane substrate-product antiporters that remove decarboxylation products to the external medium in exchange for fresh substrate2. In the case of LdcI, the lysine-cadaverine antiporter is called CadB. Recently, we determined the X-ray crystal structure of LdcI to 2.0 &#197;, and we discovered a novel small-molecule bound to LdcI the stringent response regulator guanosine 5'-diphosphate,3'-diphosphate (ppGpp) 14. The stringent response occurs when exponentially growing cells experience nutrient deprivation or one of a number of other stresses9. As a result, cells produce ppGpp which leads to a signaling cascade culminating in the shift from exponential growth to stationary phase growth10. We have demonstrated that ppGpp is a specific inhibitor of LdcI 14. Here we describe the lysine decarboxylase assay, modified from the assay developed by Phan et al.11, that we have used to determine the activity of LdcI and the effect of pppGpp/ppGpp on that activity. The LdcI decarboxylation reaction removes the &alpha;-carboxy group of L-lysine and produces carbon dioxide and the polyamine cadaverine (1,5-diaminopentane)5. L-lysine and cadaverine can be reacted with 2,4,6-trinitrobenzensulfonic acid (TNBS) at high pH to generate N,N'-bistrinitrophenylcadaverine (TNP-cadaverine) and N,N&#8242;-bistrinitrophenyllysine (TNP-lysine), respectively11. The TNP-cadaverine can be separated from the TNP-lysine as the former is soluble in organic solvents such as toluene while the latter is not (See Figure 1). The linear range of the assay was determined empirically using purified cadaverine.

An Assay for Measuring the Activity of Escherichia coli Inducible Lysine Decarboxyase

The activity of the inducible lysine decarboxylase is monitored by reacting the substrate L-lysine and the product cadaverine with 2,4,6-trinitrobenzensulfonic acid to form adducts that have differential solubility in toluene.

の活性を測定するアッセイ大腸菌誘導性リジンDecarboxyase

Escherichia coli is an enteric bacterium that is capable of growing over a wide range of pH values (pH 5 - 9)1 and, incredibly, is able to survive extreme ...

Do-It-Yourself Device for Recovery of Cryopreserved Samples Accidentally Dropped into Cryogenic Storage Tanks

Liquid nitrogen is colorless, odorless, extremely cold (-196 &deg;C) liquid kept under pressure. It is commonly used as a cryogenic fluid for long term storage of biological materials such as blood, cells and tissues 1,2. The cryogenic nature of liquid nitrogen, while ideal for sample preservation, can cause rapid freezing of live tissues on contact - known as 'cryogenic burn'2, which may lead to severe frostbite in persons closely involved in storage and retrieval of samples from Dewars. Additionally, as liquid nitrogen evaporates it reduces the oxygen concentration in the air and might cause asphyxia, especially in confined spaces2.
In laboratories, biological samples are often stored in cryovials or cryoboxes stacked in stainless steel racks within the Dewar tanks1. These storage racks are provided with a long shaft to prevent boxes from slipping out from the racks and into the bottom of Dewars during routine handling. All too often, however, boxes or vials with precious samples slip out and sink to the bottom of liquid nitrogen filled tank. In such cases, samples could be tediously retrieved after transferring the liquid nitrogen into a spare container or discarding it. The boxes and vials can then be relatively safely recovered from emptied Dewar. However, the cryogenic nature of liquid nitrogen and its expansion rate makes sunken sample retrieval hazardous. It is commonly recommended by Safety Offices that sample retrieval be never carried out by a single person. Another alternative is to use commercially available cool grabbers or tongs to pull out the vials3. However, limited visibility within the dark liquid filled Dewars poses a major limitation in their use.
In this article, we describe the construction of a Cryotolerant DIY retrieval device, which makes sample retrieval from Dewar containing cryogenic fluids both safe and easy.

Here we present a low cost, durable cryotolerant device for sample retrieval from Dewar tanks filled with liquid nitrogen. The ease of construction and modular design of the device makes the process of sample retrieval from cryogenic tanks safe and easy.

凍結保存サンプルの回復のための日曜大工のデバイスが誤って低温貯蔵タンクに落とし

Liquid nitrogen is colorless, odorless, extremely cold (-196 &deg;C) liquid kept under pressure. It is commonly used as a cryogenic fluid for long term ...

Measuring In Vitro ATPase Activity for Enzymatic Characterization

Adenosine triphosphate-hydrolyzing enzymes, or ATPases, play a critical role in a diverse array of cellular functions. These dynamic proteins can generate energy for mechanical work, such as protein trafficking and degradation, solute transport, and cellular movements. The protocol described here is a basic assay for measuring the in vitro activity of purified ATPases for functional characterization. Proteins hydrolyze ATP in a reaction that results in inorganic phosphate release, and the amount of phosphate liberated is then quantitated using a colorimetric assay. This highly adaptable protocol can be adjusted to measure ATPase activity in kinetic or endpoint assays. A representative protocol is provided here based on the activity and requirements of EpsE, the AAA+ ATPase involved in Type II Secretion in the bacterium Vibrio cholerae. The amount of purified protein needed to measure activity, length of the assay and the timing and number of sampling intervals, buffer and salt composition, temperature, co-factors, stimulants (if any), etc. may vary from those described here, and thus some optimization may be necessary. This protocol provides a basic framework for characterizing ATPases and can be performed quickly and easily adjusted as necessary.

Measuring In Vitro ATPase Activity for Enzymatic Characterization

We describe a basic protocol for quantitating in vitro ATPase activity. This protocol can be optimized based on the level of activity and requirements for a given purified ATPase.

計測<em&gt;インビトロ</em酵素特性評価のための&gt; ATPase活性

Adenosine triphosphate-hydrolyzing enzymes, or ATPases, play a critical role in a diverse array of cellular functions. These dynamic proteins can generate ...

Comparison of Three Different Methods for Determining Cell Proliferation in Breast Cancer Cell Lines

Measuring cell proliferation can be performed by a number of different methods, each with varying levels of sensitivity, reproducibility and compatibility with high-throughput formatting. This protocol describes the use of three different methods for measuring cell proliferation in vitro including conventional hemocytometer counting chamber, a luminescence-based assay that utilizes the change in the metabolic activity of viable cells as a measure of the relative number of cells, and a multi-mode cell imager that measures cell number using a counting algorithm. Each method presents its own advantages and disadvantages for the measurement of cell proliferation, including time, cost and high-throughput compatibility. This protocol demonstrates that each method could accurately measure cell proliferation over time, and was sensitive to detect growth at differing cellular densities. Additionally, measurement of cell proliferation using a cell imager was able to provide further information such as morphology, confluence and allowed for a continual monitoring of cell proliferation over time. In conclusion, each method is capable of measuring cell proliferation, but the chosen method is user-dependent.

This protocol describes the use of three different methods for analyzing cell proliferation in breast cancer cell lines. This includes the use of conventional cell counting, luminescence-based cell viability, and cell counting through the use of a cell imager. Each offers advantages for the reproducible measurement of cell proliferation.

乳癌細胞株における細胞増殖を決定するための3つの異なる方法の比較

Measuring cell proliferation can be performed by a number of different methods, each with varying levels of sensitivity, reproducibility and compatibility ...

Measuring Lactase Enzymatic Activity in the Teaching Lab

Understanding how enzymes work, and relating this to real life examples, is critical to a wide range of undergraduate degrees in the biological and biomedical sciences. This easy to follow protocol was developed for first year undergraduate pharmacy students and provides an entry-level introduction to enzyme reactions and analytical procedures for enzyme analysis. The enzyme of choice is lactase, as this represents an example of a commercially available enzyme relevant to human disease/pharmaceutical practice. Lactase is extracted from dietary supplement tablets, and assessed using a colorimetric assay based upon hydrolysis of an artificial substrate for lactase (ortho-nitrophenol-beta-D-galactopyranoside, ONPG). Release of ortho-nitrophenol following the hydrolytic cleavage of ONPG by lactase is measured by a change in absorbance at 420 nm, and the effect of the temperature on the enzymatic reaction is evaluated by carrying out the reaction on ice, at room temperature and at 37 &#176;C. More advanced analysis can be implemented using this protocol by assessing the enzyme activity under different conditions and using different reagents.

The enzymatic activity of lactase is essential for the catabolic processing of the disaccharide lactose. Here, the activity of lactase found in dietary supplements is assayed using a colorimetric assay. This provides students with an experimental platform for understanding the activity of lactase and enzyme kinetics.

教育実習でラクターゼ酵素活性の測定

Understanding how enzymes work, and relating this to real life examples, is critical to a wide range of undergraduate degrees in the biological and ...

Hybrid-Cut: An Improved Sectioning Method for Recalcitrant Plant Tissue Samples

Maintaining plant section integrity is essential for studying detailed anatomical structures at the cellular, tissue, or even organ level. However, some plant cells have rigid cell walls, tough fibers and crystals (calcium oxalate, silica, etc.), and high water content that often disrupt tissue integrity during plant tissue sectioning.
This study establishes a simple Hybrid-Cut tissue sectioning method. This protocol modifies a paraffin-based sectioning technique and improves the integrity of tissue sections from different plants. Plant tissues were embedded in paraffin before sectioning in a cryostat at -16 &#176;C. Sectioning under low temperature hardened the paraffin blocks, reduced tearing and scratching, and improved tissue integrity significantly. This protocol was successfully applied to calcium oxalate-rich Phalaenopsis orchid tissues as well as recalcitrant tissues such as reproductive organs and leaves of rice, maize, and wheat. In addition, the high quality of tissue sections from Hybrid-Cut could be used in combination with in situ hybridization (ISH) to provide spatial expression patterns of genes of interest. In conclusion, this protocol is particularly useful for recalcitrant plant tissue containing high crystal or silica content. Good quality tissue sections enable morphological and other biological studies.

This protocol describes a simple Hybrid-Cut tissue sectioning method that is useful for recalcitrant plant tissues. Good quality tissue sections enable anatomical studies and other biological studies including in situ hybridization (ISH).

ハイブリッドカット：手に負えない植物組織試料のための改善されたセクショニング方法

Maintaining plant section integrity is essential for studying detailed anatomical structures at the cellular, tissue, or even organ level. However, some ...

Dissection of the Auditory Bulla in Postnatal Mice: Isolation of the Middle Ear Bones and Histological Analysis

In most mammals, auditory ossicles in the middle ear, including the malleus, incus and stapes, are the smallest bones. In mice, a bony structure called the auditory bulla houses the ossicles, whereas the auditory capsule encloses the inner ear, namely the cochlea and semicircular canals. Murine ossicles are essential for hearing and thus of great interest to researchers in the field of otolaryngology, but their metabolism, development, and evolution are highly relevant to other fields. Altered bone metabolism can affect hearing function in adult mice, and various gene-deficient mice show changes in morphogenesis of auditory ossicles in utero. Although murine auditory ossicles are tiny, their manipulation is feasible if one understands their anatomical orientation and 3D structure. Here, we describe how to dissect the auditory bulla and capsule of postnatal mice and then isolate individual ossicles by removing part of the bulla. We also discuss how to embed the bulla and capsule in different orientations to generate paraffin or frozen sections suitable for preparation of longitudinal, horizontal, or frontal sections of the malleus. Finally, we enumerate anatomical differences between mouse and human auditory ossicles. These methods would be useful in analyzing pathological, developmental and evolutionary aspects of auditory ossicles and the middle ear in mice.

We present a protocol to isolate the auditory bulla, capsule, and ossicles from postnatal mice for whole mount and histological analysis.

生後マウスにおける聴覚ブラの解剖：中耳の骨の単離および組織学的解析

In most mammals, auditory ossicles in the middle ear, including the malleus, incus and stapes, are the smallest bones. In mice, a bony structure called ...

Adipo-Clear: A Tissue Clearing Method for Three-Dimensional Imaging of Adipose Tissue

Adipose tissue plays a central role in energy homeostasis and thermoregulation. It is composed of different types of adipocytes, as well as adipocyte precursors, immune cells, fibroblasts, blood vessels, and nerve projections. Although the molecular control of cell type specification and how these cells interact have been increasingly delineated, a more comprehensive understanding of these adipose-resident cells can be achieved by visualizing their distribution and architecture throughout the whole tissue. Existing immunohistochemistry and immunofluorescence approaches to analyze adipose histology rely on thin paraffin-embedded sections. However, thin sections capture only a small portion of tissue; as a result, the conclusions can be biased by what portion of tissue is analyzed. We have therefore developed an adipose tissue clearing technique, Adipo-Clear, to permit comprehensive three-dimensional visualization of molecular and cellular patterns in whole adipose tissues. Adipo-Clear was adapted from iDISCO/iDISCO+, with specific modifications made to completely remove the lipid stored in the tissue while preserving native tissue morphology. In combination with light-sheet fluorescence microscopy, we demonstrate here the use of the Adipo-Clear method to obtain high-resolution volumetric images&#160;of an entire adipose tissue.

Due to the high lipid content, adipose tissue has been challenging to visualize using traditional histological methods. Adipo-Clear is a tissue clearing technique that allows robust labeling and high-resolution volumetric fluorescent imaging of adipose tissue. Here, we describe the methods for sample preparation, pretreatment, staining, clearing, and mounting for imaging.

裏打ちクリア: 組織の脂肪組織の三次元イメージング法をクリア

Adipose tissue plays a central role in energy homeostasis and thermoregulation. It is composed of different types of adipocytes, as well as adipocyte ...