仕事はDOMプログラムと欧州連合コミュニティFP7 Frameworkのプログラムからグラント211684（BACSIN）を通じて戦略的環境研究のためのスウェーデンの財団（MISTRA）によってサポートされていました。私たちは、概念的な物語との助けるためにX線分析とL.唐の撮影の支援のためにJ. Engstrandに感謝します。

1。 P.の栽培と収穫プチダ <ol><li> Pのコロニーをトリプシン大豆ブロス100mlの（TSB）を接種することによりシュードモナスのスターター培養を準備プチダ細胞は、トリプシン大豆ブロス（TSA）を補充した培地で培養した。 130 rpmで設定揺れボードに30℃で文化を保つ。 </li><li> 7時間後は、新鮮なTSB-培地に本培養の最終容量のスターター培養と同等の1/10〜アリコートを転送します。 16時間130 rpmで振盪ボードに30℃で細胞を保管してください。 </li><li>成長の16時間後、細胞を室温で20分間、1,500 xgで細胞培養物を回転させて回収する。上清を除去し、細胞ペレットを増殖培地に等張であるのNaCl溶液中で再懸濁することによって細胞を洗浄。この場合、150mMのNaCl溶液を用いた。 、次いで、細胞を再び遠心分離し、上清を処方培地で細胞を再懸濁する前にデカントステップ3.2を参照してください。 </li></ol> 2。他の種の栽培<ol><li>他の細菌種にプロトコルを適合させるために栽培や収穫手順は、その種の要件に応じて変更されるべきである。収穫及び洗浄工程（複数可）中に細胞を取り扱う際浸透圧ショックを回避するために、溶液のオスモル濃度は、収穫時の増殖培地のことを一致させる必要がある。 </li></ol> 3。細胞の策定<ol><li>それぞれのマトリックス成分を計量することによって定式化ソリューションを準備し、水に溶解する。等張条件を達成するために、いずれかの賦形剤の量を調整したり、所望の重量オスモル濃度に到達するためのNaClまたはいくつかの他の細胞適合溶質を加える。このような二糖類などの低分子量物質の量は、容易に等張条件に達するように調整することができる。高分子であるポリマーのような物質については、張は、セルと互換性で調整する必要がありますリュート、 例えば塩化ナトリウムまたは二糖類。物質の任意の添加が交互に凍結乾燥挙動と細胞生存に影響を及ぼし得る製剤の物理的特性に影響を与えることに留意されたい。 </li><li>洗浄液（この場合、NaCl）を、それぞれの製剤のメディアで再懸濁細胞をデカント。 </li><li>細胞が均一に分散していることを確認します。高い粘度の配合物は、例えば 。、攪拌棒を添加し、均質な混合が達成されるまで、容器を振盪することにより混合して使用するのに対し、低粘度の配合物をボルテックスしている。 </li><li>凍結乾燥バイアルに処方を分ける。凍結乾燥中に除去される水の量を計算するために凍結乾燥前と後のバイアルを試料と、空の計量されるべきである。 </li><li>バイアルを凍結乾燥機内に封入される場合はバイアルにゴム栓を追加するには、ステップ4.3を参照してください。 </li><li>凍結乾燥前に、各製剤中の細​​胞を列挙、ステップ6を参照してください。 </li> &lt;/ OL&gt; 4。フリーズドライ<ol><li>凍結乾燥条件は、配合物の物理的特性に調整されなければならない。最も重要なパラメータは、この場合、ガラス転移温度、Tgは、配合物、水が依然として存在であることを示すために、凍結濃縮試料についてのTg &#39;を付している。凍結濃縮製剤のTg &#39;を容易に示差走査熱量測定（DSC）を用いて測定され、ステップ7を参照してください。 </li><li>試料の温度は試料のTgを下回ると、チャンバ圧力は、すなわち、セカンダリ製剤中の氷、すなわち一次乾燥し、残留水を迅速に昇華を可能にすることを常にあるように、凍結乾燥プロセスのパラメータを調整する乾燥。試料温度は、乾燥プロセスの間に &quot;Tgを超えている場合は有意に細胞の生存を減少させることができる試料の構造崩壊の大きな危険性がある。 </li><li> fの後に乾燥した製品を保護するためにreeze乾燥サンプル雰囲気が制御されなければならない。可能であれば、真空凍結乾燥サイクルの終了時に解放される前に、凍結乾燥機でサンプルを密封する。あるいはバイアルは好ましい雰囲気を充填することができる。それは、ストレージ大気中の湿気や酸素の存在のような周囲条件にサンプルをさらすことを避けるために重要なのは、細胞の生存に影響を与える。 </li><li>バイアル重量を量る。 </li></ol> 5。水分補給<ol><li>イオンと滅菌水でサンプルを再水和。添加する水の量は、凍結乾燥の間に除去し、空バイアル、凍結乾燥前と後の試料と同じバイアルの重量から計算される量とが同じでなければならない。サンプルは今、もう一度、次にソリューションが均質に表示されるまでボルテックス。 </li></ol> 6。列挙<ol><li>各サンプルから100μlのを描画し、10倍連続希釈を行います。統合の希釈から残りの100μlをTSAプレート上にメッキされています。プレートは、必要な温度および時間でインキュベートする。 </li></ol> 7。凍結挙動の定式化の特性<ol><li>少量、5取る - 10 mgの、サンプルのと蓋付きDSC-アルミパンで囲みます。リファレンスとして空の鍋を準備します。 </li><li> DSC温度スキャンプログラムを設定します。冷却プログラムは、凍結乾燥番組で凍結工程を模倣するように設定されている。これは、冷却速度論のように行われる水和製剤のTg &#39;に影響を与えることができる。加熱スキャンによく、通常調査製剤の予想Tgが &#39;、100℃以下の温度を下げる開始する前に</li><li> 40℃/分が使用されている - 適切な加熱速度、5の通常加熱速度を選択してください。記録された熱流量信号がワットで表され、加熱速度によって影響を受ける。高い加熱速度はTgが &#39;の大きな信号を与える。 </li><li>温度範囲を設定しているので、私tはTgが &#39;と製剤の融解の両方をカバーしています。 </li></ol> 8。和製剤の表面張力測定<ol><li>この実験で使用実験は、表面を測定するデュNoüy方法に従ってされる。 </li><li>慎重にプラチナリングと測定容器を清掃します。容器は、アセトンですすぎ、糸くずの出ないティッシュで拭いた後、無色の炎で内側に燃焼される。リングは無色の炎で赤点灯します。 </li><li>溶液を容器に記入し、表面が測定する前に解決することができます。平衡状態だけ久しぶりに達したソリューションについては、 例えばポリマーは、ここで使用される単純なセットアップでは定性的なデータを提供します。 </li><li>高い粘度、 例えば 2％の溶液（w / w）のHEC又はHPMCとの配合物については、表面張力が低い濃度の溶液で測定する必要があり、その後補外。これは、その事実を利用することによって行うことができる0.5％以下の濃度（w / w）の時の表面張力レベルオフの低下。 </li></ol> 9。乾燥製剤のX線解析<ol><li>マトリックス/細菌の少量を取り、サンプルホルダーにそれをロードします。 </li><li> X線回折装置に試料ホルダーをマウントします。 </li><li>サンプル内の任意の結晶相の存在を分析したBrukerからEVAプログラムパッケージを使用することができる。 </li></ol> 10。電子顕微鏡法<ol><li>バイアルのうちマトリックス/細菌の少量を取り、SEMスタブにそれを修正する。 </li><li>スパッタコーター（本研究で使用するサーモVGScientificポーラロンSC7640）やコートのAu / Pd又はPtを数nmと、試料中のSEMホルダーをロードします。これらの実験ではスパッタのパラメータは次のとおりだった：1,900 V、20ミリアンペア、そして20秒〜5のために - は10nmのAu / Pdをコーティング。コー​​ティングは、画像取得時の電気の帯電を軽減します。充電が解消されないと、画像の原因となるかどうかは、薄いコーティングで開始することが推奨され、アーティファクトは、試料を再びコーティングされるべきである。 </li><li> SEM室にSEMホルダーをロードします。適切な撮像パラメータを選択します。 図2（FEIストラータDB235）で使用される楽器のために私達は5 kVの加速電圧、スポットサイズ3、5ミリメートルと二次電子検出器の作動距離を使用していました。 </li><li>場合により、さらなる詳細を明らかにするためにポリマー中に埋め込まれた細菌の断面を切断するために集束イオンビームを使用することが可能である。 </li></ol>

<ol>
	<li>Wessman, P., Mahlin, D., 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=Impact+of+matrix+properties+on+the+survival+of+freeze-dried+bacteria.">Impact of matrix properties on the survival of freeze-dried bacteria.</a> J. Sci. Food Agric. 91 (14), 2518-2528 (2011).</li><li>Ablett, S., Izzard, M. J., 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=Differential+Scanning+Calorimetric+Study+of+Frozen+Sucrose+and+Glycerol+Solutions.">Differential Scanning Calorimetric Study of Frozen Sucrose and Glycerol Solutions.</a> Journal of the Chemical Society-Faraday Transactions. 88 (6), 789-794 (1992).</li><li>Knopp, S. A., Chongprasert, S., 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+relationship+between+type+TMDSC+curve+of+frozen+sucrose+solutions+and+collapse+during+freeze-drying.">The relationship between type TMDSC curve of frozen sucrose solutions and collapse during freeze-drying.</a> Journal of Thermal Analysis and Calorimetry. 54 (2), 659-672 (1998).</li><li>Crowe, J. H., Leslie, S. B., 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=Is+Vitrification+Sufficient+to+Preserve+Liposomes+during+Freeze-Drying.">Is Vitrification Sufficient to Preserve Liposomes during Freeze-Drying.</a> Cryobiology. 31 (4), 355-366 (1994).</li><li>Jain, P., Sen, S., 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=Effect+of+glass-forming+biopreservatives+on+head+group+rotational+dynamics+in+freeze-dried+phospholipid+bilayers:+A+P-31+NMR+study.">Effect of glass-forming biopreservatives on head group rotational dynamics in freeze-dried phospholipid bilayers: A P-31 NMR study.</a> Journal of Chemical Physics. 131 (2), (2009).</li><li>Stock, J. B., Rauch, B., 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=Periplasmic+Space+in+Salmonella-Typhimurium+and+Escherichia-Coli.">Periplasmic Space in Salmonella-Typhimurium and Escherichia-Coli.</a> Journal of Biological Chemistry. 252 (21), 7850-7861 (1977).</li><li>Crowe, J. H., Hoekstra, F. 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=Anhydrobiosis.">Anhydrobiosis.</a> Annual Review of Physiology. 54, 579-599 (1992).</li><li>Leslie, S. B., Israeli, 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=Trehalose+and+Sucrose+Protect+Both+Membranes+and+Proteins+in+Intact+Bacteria+during+Drying.">Trehalose and Sucrose Protect Both Membranes and Proteins in Intact Bacteria during Drying.</a> Applied and Environmental Microbiology. 61 (10), 3592-3597 (1995).</li><li>Nesarikar, V. V., Nassar, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+cations+and+anions+on+glass+transition+temperatures+in+excipient+solutions.">Effect of cations and anions on glass transition temperatures in excipient solutions.</a> Pharmaceutical Development and Technology. 12 (3), 259-264 (2007).</li><li>You, Y., Ludescher, R. D. <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+sodium+chloride+on+molecular+mobility+in+amorphous+sucrose+detected+by+phosphorescence+from+the+triplet+probe+erythrosin+B.">The effect of sodium chloride on molecular mobility in amorphous sucrose detected by phosphorescence from the triplet probe erythrosin B.</a> Carbohydr. Res. 343 (2), 350-363 (2008).</li><li>Crowe, J. H., Hoekstra, F. A., Nguyen, K. H. N., Crowe, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+vitrification+involved+in+depression+of+the+phase+transition+temperature+in+dry+phospholipids.">Is vitrification involved in depression of the phase transition temperature in dry phospholipids.</a> Biochim. Biophys. Acta Biomembr. 1280, 187-196 (1996).</li></ol>

利害の衝突は宣言されていない。

この研究のための動機は、凍結乾燥中の細胞生存に重要であり得るいくつかの製剤特性を検討した。 図1A、異なる製剤の支持細胞の生存が類似している傾向にどれだけに示すように、真性乾燥耐性は、異なる種の間で変化するものの。それはスクロースおよびフィコールの比較で開始することが有益である。これは、細胞生存を支持するための製剤の重要な要因は、このように?...

<table border="1">
	<tbody>
		<tr>
			<td>Name of the reagent</td>
			<td>Company</td>
			<td>Catalogue number</td>
			<td>Comments (optional)</td>
		</tr>
		<tr>
			<td>Ficoll PM 400</td>
			<td>GE-healthcare</td>
			<td>17-0300-10</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>HEC (Natrosol-M Pharm Grade)</td>
			<td>Ashland</td>
			<td>&nbsp;</td>
			<td>Gift from Ashland</td>
		</tr>
		<tr>
			<td>HPMC (Methocel F4M)</td>
			<td>Dow</td>
			<td>&nbsp;</td>
			<td>Gift from the Department of Pharmacy, Uppsala University</td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Sigma-Aldrich</td>
			<td>S2395</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sigma-Aldrich</td>
			<td>71376</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Tryptic Soy broth</td>
			<td>Merck</td>
			<td>105459</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Tryptic Soy Agar</td>
			<td>Merck</td>
			<td>105458</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Lyostar II</td>
			<td>FTS Kinetics</td>
			<td>N.A.</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Pyris Diamond DSC</td>
			<td>Perkin-Elmer</td>
			<td>N.A.</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Bruker AXS SMART CCD 1k Diffractometer</td>
			<td>Bruker</td>
			<td>N.A</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Dual-beam FEI Strata DB235 FIB/SEM</td>
			<td>FEI</td>
			<td>N.A</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Kr&uuml;ss Educational Tensiometer</td>
			<td>Kr&uuml;ss</td>
			<td>N.A.</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

formulations for freeze-drying of bacteria and their influence on cell survival

セルラ水を可逆的に保管を容易にするために、微生物を不活性化するために除去することができる。除去のそのような方法の一つは、穏やかな脱水方法考えられる凍結乾燥である。乾燥中の細胞生存を促進するために、細胞は、しばしば、予め処方される。製剤は、細胞を埋め込み、凍結乾燥中のセルに課される種々の有害なストレスからそれらを保護マトリックスを形成する。ここでは、凍結乾燥後の細胞の生存率を評価する一般的な方法を提示し、我々は、4つの異なる処方で得られた結果と比較することによってそれを示している：二糖スクロース、ポリマーフィコールPM400由来のスクロースを、各多糖類、ヒドロキシエチルセルロース（HEC細菌の2株、P.上）とヒドロキシプロピルメチルセルロース（HPMC）、 プチダ KT2440とA. chlorophenolicus A6。本研究では、凍結乾燥用製剤を調製する方法と、機械式を調査する方法を示し示差走査熱量測定（DSC）、表面張力の測定は、X線分析、および電子顕微鏡を用いて、生存率にそれらのデータを関連付ける製剤を特徴付けることによって再水和後の細胞生存のイズム。ポリマーは、程度の差は、それぞれの多糖類に似た白糖の単量体構造を得るために選ばれました。この方法の設定を用いて、我々は、ポリマーは、製剤の特定の物理的特性が制御される場合、二糖類1と効果的に細胞生存をサポートできることを示した。

製剤組成物、凍結製剤の加熱時にDSCによって記録された熱事象、乾燥試料の構造及び製剤溶液の表面張力の表1に表示されるデータである。スクロースの Tg &#39;は-40°C 2、図3に決定された、20％w / wの下方スクロース濃度を検出するために困難であり得る。 -35の熱イベント°Cは、おそらく氷の溶解2の発症に関連しています。結晶構造HECとHPMC試料でX?...

Watch this Scientific Journal Video about Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival at JoVE.com

Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival

凍結乾燥は、多くの場合、生菌細胞の乾燥製品を得るための簡単​​で便利な方法です。プロセスの問題は、細胞生存ある。ここで我々は細部、凍結乾燥時の細胞の生存が使用製剤の特性によって影響されるか調査する手順を。

細菌の凍結乾燥と細胞の生存への影響のための処方

Cellular water can be removed to reversibly inactivate microorganisms to facilitate storage. One such method of removal is freeze-drying, which is ...

formulations-for-freeze-drying-bacteria-their-influence-on-cell

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Biology

23.2K ビュー.  Swedish University of Agricultural Sciences. 凍結乾燥は、多くの場合、生菌細胞の乾燥製品を得るための簡単​​で便利な方法です。プロセスの問題は、細胞生存ある。ここで我々は細部、凍結乾燥時の細胞の生存が使用製剤の特性によって影響されるか調査する手順を。

ビデオ: Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival

Obtaining Hemocytes from the Hawaiian Bobtail Squid Euprymna scolopes and Observing their Adherence to Symbiotic and Non-Symbiotic Bacteria

Studies concerning the role of the immune system in mediating molecular signaling between beneficial bacteria and their hosts have, in recent years, made significant contributions to our understanding of the co-evolution of eukaryotes with their microbiota. The symbiotic association between the Hawaiian bobtail squid, Euprymna scolopes and the bioluminescent bacterium Vibrio fischeri has been utilized as a model system for understanding the effects of beneficial bacteria on animal development. Recent studies have shown that macrophage-like hemocytes, the sole cellular component of the squid host's innate immune system, likely play an important role in mediating the establishment and maintenance of this association. This protocol will demonstrate how to obtain hemocytes from E. scolopes and then use these cells in bacterial binding assays. Adult squid are first anesthetized before hemolymph is collected by syringe from the main cephalic blood vessel. The host hemocytes, contained in the extracted hemolymph, are adhered to chambered glass coverslips and then exposed to green fluorescent protein-labeled symbiotic Vibrio fischeri and non-symbiotic Vibrio harveyi. The hemocytes are counterstained with a fluorescent dye (Cell Tracker Orange, Invitrogen) and then visualized using fluorescent microscopy.

Obtaining Hemocytes from the Hawaiian Bobtail Squid Euprymna scolopes and Observing their Adherence to Symbiotic and Non-Symbiotic Bacteria

This video will demonstrate how to obtain hemocytes (blood cells) from the Hawaiian bobtail squid, Euprymna scolopes for use in cell biological and bacterial adhesion assays. Hemocytes will be stained with a fluorescent dye and exposed to GFP-labeled bacteria.

ハワイのボブテイルイカから血球の入手 Euprymna scolopesと共生と非共生細菌への遵守を観察

Studies concerning the role of the immune system in mediating molecular signaling between beneficial bacteria and their hosts have, in recent years, made ...

生物学

Detection of Post-translational Modifications on Native Intact Nucleosomes by ELISA

The genome of eukaryotes exists as chromatin which contains both DNA and proteins. The fundamental unit of chromatin is the nucleosome, which contains 146 base pairs of DNA associated with two each of histones H2A, H2B, H3, and H41. The N-terminal tails of histones are rich in lysine and arginine and are modified post-transcriptionally by acetylation, methylation, and other post-translational modifications (PTMs). The PTM configuration of nucleosomes can affect the transcriptional activity of associated DNA, thus providing a mode of gene regulation that is epigenetic in nature 2,3. We developed a method called nucleosome ELISA (NU-ELISA) to quantitatively determine global PTM signatures of nucleosomes extracted from cells. NU-ELISA is more sensitive and quantitative than western blotting, and is useful to interrogate the epiproteomic state of specific cell types. This video journal article shows detailed procedures to perform NU-ELISA analysis.

Nucleosome ELISA (NU-ELISA) is a sensitive and quantitative method to detect global patterns of post-translational modifications in preparations of native, intact nucleosomes. These modifications include methylations, acetylations, and phosphorylations at specific histone amino acid residues, and hence NU-ELISA provides a global proteomic assay of the overall chromatin modification states of specific cell types.

ELISAによるネイティブ無傷ヌクレオソーム上の翻訳後修飾の検出

The genome of eukaryotes exists as chromatin which contains both DNA and proteins. The fundamental unit of chromatin is the nucleosome, which contains 146 ...

Analyzing the Function of Small GTPases by Microinjection of Plasmids into Polarized Epithelial Cells

Epithelial cells polarize their plasma membrane into biochemically and functionally distinct apical and basolateral domains where the apical domain faces the 'free' surfaces and the basolateral membrane is in contact with the substrate and neighboring cells. Both membrane domains are separated by tight junctions, which form a diffusion barrier. Apical-basolateral polarization can be recapitulated successfully in culture when epithelial cells such as Madin-Darby Canine Kidney (MDCK) cells are seeded at high density on polycarbonate filters and cultured for several days 1 2. Establishment and maintenance of cell polarity is regulated by an array of small GTPases of the Ras superfamily such as RalA, Cdc42, Rab8, Rab10 and Rab13 3 4 5 6 7. Like all GTPases these proteins cycle between an inactive GDP-bound state and an active GTP-bound state. Specific mutations in the nucleotide binding regions interfere with this cycling 8. For example, Rab13T22N is permanently locked in the GDP-form and thus dubbed 'dominant negative', whereas Rab13Q67L can no longer hydrolyze GTP and is thus locked in a 'dominant active' state 7. To analyze their function in cells both dominant negative and dominant active alleles of GTPases are typically expressed at high levels to interfere with the function of the endogenous proteins 9. An elegant way to achieve high levels of overexpression in a short amount of time is to introduce the plasmids encoding the relevant proteins directly into the nuclei of polarized cells grown on filter supports using microinjection technique. This is often combined with the co-injection of reporter plasmids that encode plasma membrane receptors that are specifically sorted to the apical or basolateral domain. A cargo frequently used to analyze cargo sorting to the basolateral domain is a temperature sensitive allele of the vesicular stomatitis virus glycoprotein (VSVGts045) 10. This protein cannot fold properly at 39&deg;C and will thus be retained in the endoplasmic reticulum (ER) while the regulatory protein of interest is assembled in the cytosol. A shift to 31&deg;C will then allow VSVGts045 to fold properly, leave the ER and travel to the plasma membrane 11. This chase is typically performed in the presence of cycloheximide to prevent further protein synthesis leading to cleaner results. Here we describe in detail the procedure of microinjecting plasmids into polarized cells and subsequent incubations including temperature shifts that allow a comprehensive analysis of regulatory proteins involved in basolateral sorting.

This article details the procedures involved in overexpression and analysis of small GTPases in polarized epithelial cells using microinjection technique.

偏上皮細胞へのプラスミドのマイクロインジェクションによる低分子量GTPaseの機能を解析する

Epithelial cells polarize their plasma membrane into biochemically and functionally distinct apical and basolateral domains where the apical domain faces ...

Single Cell Transcriptional Profiling of Adult Mouse Cardiomyocytes

While numerous studies have examined gene expression changes from homogenates of heart tissue, this prevents studying the inherent stochastic variation between cells within a tissue. Isolation of pure cardiomyocyte populations through a collagenase perfusion of mouse hearts facilitates the generation of single cell microarrays for whole transcriptome gene expression, or qPCR of specific targets using nanofluidic arrays. We describe here a procedure to examine single cell gene expression profiles of cardiomyocytes isolated from the heart. This paradigm allows for the evaluation of metrics of interest which are not reliant on the mean (for example variance between cells within a tissue) which is not possible when using conventional whole tissue workflows for the evaluation of gene expression (Figure 1). We have achieved robust amplification of the single cell transcriptome yielding micrograms of double stranded cDNA that facilitates the use of microarrays on individual cells. In the procedure we describe the use of NimbleGen arrays which were selected for their ease of use and ability to customize their design. Alternatively, a reverse transcriptase - specific target amplification (RT-STA) reaction, allows for qPCR of hundreds of targets by nanofluidic PCR. Using either of these approaches, it is possible to examine the variability of expression between cells, as well as examining expression profiles of rare cell types from within a tissue. Overall, the single cell gene expression approach allows for the generation of data that can potentially identify idiosyncratic expression profiles that are typically averaged out when examining expression of millions of cells from typical homogenates generated from whole tissues.

Single cell expression profiling allows the detailed gene expression analysis of individual cells. We describe methods for the isolation of cardiomyocytes, and preparing the resulting lysates for either whole transcriptome microarray or qPCR of specific targets.

成体マウスの心筋細胞の単一細胞転写プロファイリング

While numerous studies have examined gene expression changes from homogenates of heart tissue, this prevents studying the inherent stochastic variation ...

Isolation and Culture of Individual Myofibers and their Satellite Cells from Adult Skeletal Muscle

Muscle regeneration in the adult is performed by resident stem cells called satellite cells. Satellite cells are defined by their position between the basal lamina and the sarcolemma of each myofiber. Current knowledge of their behavior heavily relies on the use of the single myofiber isolation protocol. In 1985, Bischoff described a protocol to isolate single live fibers from the Flexor Digitorum Brevis (FDB) of adult rats with the goal to create an in vitro system in which the physical association between the myofiber and its stem cells is preserved 1. In 1995, Rosenblattmodified the Bischoff protocol such that myofibers are singly picked and handled separately after collagenase digestion instead of being isolated by gravity sedimentation 2, 3. The Rosenblatt or Bischoff protocol has since been adapted to different muscles, age or conditions 3-6. The single myofiber isolation technique is an indispensable tool due its unique advantages. First, in the single myofiber protocol, satellite cells are maintained beneath the basal lamina. This is a unique feature of the protocol as other techniques such as Fluorescence Activated Cell Sorting require chemical and mechanical tissue dissociation 7. Although the myofiber culture system cannot substitute for in vivo studies, it does offer an excellent platform to address relevant biological properties of muscle stem cells. Single myofibers can be cultured in standard plating conditions or in floating conditions. Satellite cells on floating myofibers are subjected to virtually no other influence than the myofiber environment. Substrate stiffness and coating have been shown to influence satellite cells' ability to regenerate muscles 8, 9 so being able to control each of these factors independently allows discrimination between niche-dependent and -independent responses. Different concentrations of serum have also been shown to have an effect on the transition from quiescence to activation. To preserve the quiescence state of its associated satellite cells, fibers should be kept in low serum medium 1-3. This is particularly useful when studying genes involved in the quiescence state. In serum rich medium, satellite cells quickly activate, proliferate, migrate and differentiate, thus mimicking the in vivo regenerative process 1-3. The system can be used to perform a variety of assays such as the testing of chemical inhibitors; ectopic expression of genes by virus delivery; oligonucleotide based gene knock-down or live imaging. This video article describes the protocol currently used in our laboratory to isolate single myofibers from the Extensor Digitorum Longus (EDL) muscle of adult mice (6-8 weeks old).

Isolation and culture of myofibers is the gold standard in vitro system to study the transition of satellite cells through quiescence, activation and differentiation. Importantly, the single myofiber culture system preserves the myofiber/stem cell association, which is an essential component of the muscle stem cell niche.

成人骨格筋からの個々の筋線維とその衛星細胞の単離および培養

Muscle  regeneration in the adult is performed by resident stem cells called satellite  cells. Satellite cells are defined by  their position between the ...

Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis

Anastasis (Greek for &#8220;rising to life&#8221;) refers to the recovery of dying cells. Before these cells recover, they have passed through important checkpoints of apoptosis, including mitochondrial fragmentation, release of mitochondrial cytochrome c into the cytosol, activation of caspases, chromatin condensation, DNA damage, nuclear fragmentation, plasma membrane blebbing, cell shrinkage, cell surface exposure of phosphatidylserine, and formation of apoptotic bodies. Anastasis can occur when apoptotic stimuli are removed prior to death, thereby allowing dying cells to reverse apoptosis and potentially other death mechanisms. Therefore, anastasis appears to involve physiological healing processes that could also sustain damaged cells inappropriately. The functions and mechanisms of anastasis are still unclear, hampered in part by the limited tools for detecting past events after the recovery of apparently healthy cells. Strategies to detect anastasis will enable studies of the physiological mechanisms, the hazards of undead cells in disease pathology, and potential therapeutics to modulate anastasis. Here, we describe effective strategies using live cell microscopy and a mammalian caspase biosensor&#160;for identifying and tracking anastasis in mammalian cells.

The term anastasis refers to the phenomenon in which dying cells reverse a cell suicide process at a late stage, repair themselves, and ultimately survive. Here we demonstrate protocols for detecting and tracking cells that undergo anastasis.

トラッキングアナスタシス、アポトーシスを逆に細胞生存現象のための戦略

Anastasis (Greek for &#8220;rising to life&#8221;) refers to the recovery of dying cells. Before these cells recover, they have passed through important ...

A Standardized Method for the Analysis of Liver Sinusoidal Endothelial Cells and Their Fenestrations by Scanning Electron Microscopy

Liver sinusoidal endothelial cells are the gateway to the liver, their transcellular fenestrations allow the unimpeded transfer of small and dissolved substances from the blood into the liver parenchyma for metabolism and processing. Fenestrations are dynamic structures - both their size and/or number can be altered in response to various physiological states, drugs, and disease, making them an important target for modulation. An understanding of how LSEC morphology is influenced by various disease, toxic, and physiological states and how these changes impact on liver function requires accurate measurement of the size and number of fenestrations. In this paper, we describe scanning electron microscopy fixation and processing techniques used in our laboratory to ensure reproducible specimen preparation and accurate interpretation. The methods include perfusion fixation, secondary fixation and dehydration, preparation for the scanning electron microscope and analysis. Finally, we provide a step by step method for standardized image analysis which will benefit all researchers in the field.

The fenestrated liver sinusoidal endothelial cell is a biologically important filter system that is highly influenced by various diseases, toxins, and physiological states. These changes significantly impact on liver function. We describe methods for the standardisation of the measurement of the size and number of fenestrations in these cells.

走査型電子顕微鏡による肝類洞内皮細胞およびそれらの開窓の分析のための標準化された方法

Liver sinusoidal endothelial cells are the gateway to the liver, their transcellular fenestrations allow the unimpeded transfer of small and dissolved ...

Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions

Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions

Rotifers are microscopic zooplankton used as models in ecotoxicological and aging studies. Here we provide a protocol for powerful and reproducible measurement of survival time in Brachionus rotifers. Synchronization of culture conditions over several generations is of particular importance because maternal condition affects life history of offspring.

生存時間の測定で<em&gt; Brachionus</em&gt;ワムシ：母性条件の同期

Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short ...

Investigating the Detrimental Effects of Low Pressure Plasma Sterilization on the Survival of Bacillus subtilis Spores Using Live Cell Microscopy

Plasma sterilization is a promising alternative to conventional sterilization methods for industrial, clinical, and spaceflight purposes. Low pressure plasma (LPP) discharges contain a broad spectrum of active species, which lead to rapid microbial inactivation. To study the efficiency and mechanisms of sterilization by LPP, we use spores of the test organism Bacillus subtilis because of their extraordinary resistance against conventional sterilization procedures. We describe the production of B. subtilis spore monolayers, the sterilization process by low pressure plasma in a double inductively coupled plasma reactor, the characterization of spore morphology using scanning electron microscopy (SEM), and the analysis of germination and outgrowth of spores by live cell microscopy. A major target of plasma species is genomic material (DNA) and repair of plasma-induced DNA lesions upon spore revival is crucial for survival of the organism. Here, we study the germination capacity of spores and the role of DNA repair during spore germination and outgrowth after treatment with LPP by tracking fluorescently-labelled DNA repair proteins (RecA) with time-resolved confocal fluorescence microscopy. Treated and untreated spore monolayers are activated for germination and visualized with an inverted confocal live cell microscope over time to follow the reaction of individual spores. Our observations reveal that the fraction of germinating and outgrowing spores is dependent on the duration of LPP-treatment reaching a minimum after 120 s. RecA-YFP (yellow fluorescence protein) fluorescence was detected only in few spores and developed in all outgrowing cells with a slight elevation in LPP-treated spores. Moreover, some of the vegetative bacteria derived from LPP-treated spores showed an increase in cytoplasm and tended to lyse. The described methods for analysis of individual spores could be exemplary for the study of other aspects of spore germination and outgrowth.

Investigating the Detrimental Effects of Low Pressure Plasma Sterilization on the Survival of Bacillus subtilis Spores Using Live Cell Microscopy

This protocol illustrates the important consecutive steps required to assess the relevance of monitoring vitality parameter and DNA repair processes in reviving Bacillus subtilis spores after treatment with low pressure plasma by tracking fluorescence-labelled DNA repair proteins via time-resolved confocal microscopy and scanning electron microscopy.

有害な効果の低圧プラズマ滅菌を使用して住んでいる携帯顕微鏡枯草菌胞子の生存に調査

Plasma sterilization is a promising alternative to conventional sterilization methods for industrial, clinical, and spaceflight purposes. Low pressure ...

Quantification of Site-specific Protein Lysine Acetylation and Succinylation Stoichiometry Using Data-independent Acquisition Mass Spectrometry

Post-translational modification (PTM) of protein lysine residues by N&#400;-acylation induces structural changes that can dynamically regulate protein functions, for example, by changing enzymatic activity or by mediating interactions. Precise quantification of site-specific protein acylation occupancy, or stoichiometry, is essential for understanding the functional consequences of both global low-level stoichiometry and individual high-level acylation stoichiometry of specific lysine residues. Other groups have reported measurement of lysine acetylation stoichiometry by comparing the ratio of peptide precursor isotopes from endogenous, natural abundance acylation and exogenous, heavy isotope-labeled acylation introduced after quantitative chemical acetylation of proteins using stable isotope-labeled acetic anhydride. This protocol describes an optimized approach featuring several improvements, including: (1) increased chemical acylation efficiency, (2) the ability to measure protein succinylation in addition to acetylation, and (3) improved quantitative accuracy due to reduced interferences using fragment ion quantification from data-independent acquisitions (DIA) instead of precursor ion signal from data-dependent acquisition (DDA). The use of extracted peak areas from fragment ions for quantification also uniquely enables differentiation of site-level acylation stoichiometry from proteolytic peptides containing more than one lysine residue, which is not possible using precursor ion signals for quantification. Data visualization in Skyline, an open source quantitative proteomics environment, allows for convenient data inspection and review. Together, this workflow offers unbiased, precise, and accurate quantification of site-specific lysine acetylation and succinylation occupancy of an entire proteome, which may reveal and prioritize biologically relevant acylation sites.

Here, we present unbiased quantification of site-specific protein acetylation and/or succinylation occupancy (stoichiometry) of an entire proteome through a ratiometric analysis of endogenous modifications to modifications introduced after quantitative chemical acylation using stable isotope-labeled anhydrides. In combination with sensitive data-independent acquisition mass spectrometry, accurate site occupancy measurements are obtained.

部位特異的タンパク質のリジンのアセチル化のサクシニル化化学量論組成データに依存しない取得質量分析法による定量

Post-translational modification (PTM) of protein lysine residues by N&#400;-acylation induces structural changes that can dynamically regulate protein ...