著者は、顕微鏡実験で優れた技術支援のためにグレン・スローカム（ウィスコンシン医科大学）とコリーンA.ラビン（ニコンインスツルメンツ社）を感謝したいと思います。この研究は、（OPO）はアメリカ心臓協会13GRNT16220002、（TSP）に国立衛生研究所（TSPに）R01 HL108880（AS）は、（OPO）にR01 DK095029とK99 HL116603を付与し、国立腎臓財団IG1724によってサポートされていましたし、 （DVI）に米国腎臓学会からベン・J・リップス研究フェローシップ。

以下に記載の実験手順は、ウィスコンシン医科大学で機関動物実験委員会によって承認され、ヒューストンでのテキサス大学健康科学センター、実験動物の管理と使用に関する健康ガイドの国立研究所に従ってありました。 図1は、組織の単離および処理手順の主要ステップを示しています。簡単に言うと、PCKまたはSDラットからの腎臓は健康な非ダイヤルした細管または嚢胞のいずれかから集合管の上皮単層の手動単離のために使用されています。ここでは、4-16週齢PCKラット10,13から腎臓を検討しました。 腎嚢胞との接続細管の1の単離（CNT）/ダクト（CD）セグメントの収集<ol><li>イソフルラン（5％誘導、1.5〜2.5％のメンテナンス）/医療グレードのO 2または他の承認された方法で実験動物を麻酔。動物は、継続的に適切なルを確保するために監視されなければなりません麻酔のVEL。安定した呼吸数及びつま先ピンチ反応は、適切な麻酔を確認するために使用されます。 </li><li>開腹術を行い、腹部大動脈17を介してリン酸緩衝生理食塩水（PBS）で腎臓をフラッシュします。 <ol><li>ポリエチレン管カテーテル（PE50）を準備し、PBSで充填されたシリンジポンプに接続します。側、腸間膜や腹腔動脈分岐で下行大動脈へのアクセスを取得するために綿棒で腹部臓器をシフトする側から腹部全体の横腹部切開を行い、その後、白線に沿って皮膚や腹壁をカットします。彼らの乾燥を防ぐために、さらに手順の間に温かい生理食塩水で内臓を湿ら。 </li><li>腸間膜や腹腔動脈とダイアフラム下大動脈の周りに他の合字（＃2）（ネクタイしない）の周りに1合字（＃1）を配置します。静かに分離します。細い鉗子でその周りの結合組織を解剖し、2合字を配置することによって鈍ら腹 〜3左腎動脈（＃3）と腸骨動脈の分岐部（＃4）上記下記ミリメートル。 </li><li>リガチャー＃4を接続し、左腎動脈結紮＃3との間の大動脈の周りの血管クランプを取り付けます。大動脈のカテーテルを挿入するクランプとリガチャー＃4との間の切開を行い、しっかりとカテーテルを固定するための合字＃3を使用しています。 </li><li>クランプを解除し、血液パルスが適切な設置を確実にするためにカテーテルに表示されていることを確認してください。 6ミリリットル/分の速度で灌流を開始し、タイは＃1と＃2を合字、左腎静脈を切りました。臓器が完全にブランチングされるまで1〜2分間フラッシュし続けます。 </li><li>腎臓の血管を切り取り、尿道及び腎臓を収集するためにハサミで結合し、脂肪組織を囲みます。その後、腎臓カプセルに短い涙を作り、それらをカプセル化解除するために腎臓の皮をむきます。氷冷PBSに腎臓を置きます。安楽死は、開胸術によって確認されました。 </li></ol></li><li>ポリ-L-リジンで被覆した5×5 mmのカバーガラスチップを準備します。カバーGLAをカットダイヤモンド鉛筆と場所、各ガラスチップ上に0.01％滅菌濾過したポリ-L-リジン溶液約20μlのssです。解剖のために生理食塩水や時計職人鉗子の二組を準備します。 </li><li> 〜1〜2ミリメートルの厚さのスライスに前頭面に沿ってカミソリの刃で腎臓をカットします。実体顕微鏡下でのスライスの1つを配置します。組織の単離を、氷冷生理食塩水で行う必要があります。 </li><li>ラウンド形状の空洞（ 図2A）のように実体顕微鏡下嚢胞を見つけ;その壁は、多くの場合、増殖し、血管の顕著なネットワークが含まれています。先の細いピンセットを使用して、単層の面積を得るためにできるだけ薄い嚢胞の内部上皮層を分析。ポリ-L-リジンで被覆されたガラスチップに接続します。スティッキーポリ-L-リジンの表面は、研究者がしっかりとガラスの内部嚢胞層を配置することができます。ピペット（ 図2B）へのアクセスを提供するために、頂端側を上にして嚢胞を公開します。 </li><li> PCKまたはSDラットの子供を使用してください非拡張型CNT / CCDsegments 18-21の単離のための乳頭を含むネイ中央スライス。 注：乳頭状の組織は、皮質よりも耐久性があり、鉗子で乳頭管状バンドを保持し、スライス軸、半径に沿って引き裂くことによって薄いセクターに切断することができます。個々の細管が表示され、カバーガラスチップ上に配置されるように引き出すことができます。 </li><li> 、分岐によって近位尿細管と大きな目立つ可視セル（ 図2C）より高い透明性のCNT / CCDセグメントを特定します。マイクロピペットを駆動するのに適したマイクロマニピュレータを備えた顕微鏡下で添付細管とカバーガラスチップを置きます。ガラスにそれらのエッジをシャープにマイクロピペットを分割オープン細管を使用し、添付すること（ 図2D）先端面にアクセスできるようにします。 </li></ol> 2.シングルチャネルパッチクランプ電気生理学<ol><li>浴溶液でパッチクランプ室を充填し、カバーガラスチップを転送します室に分離された組織と。パッチクランプマイクロピペットが信頼のセル（セル付）測定のための7-10MΩの抵抗を持っていることを確認してください。 </li><li>セル付測定では、20倍に増幅利得比を設定し、8極ベッセルフィルタにより300 Hzの電流を低域通過。 ENaCチャネルの監視については、mMの中で、浴溶液を使用する：150のNaCl、1のCaCl 2、2のMgCl 2、10 HEPES（pH7.4）で、ピペット：140のLiCl、2のMgCl 2および10 HEPES（pHは7.4）。 </li><li>セル接続モード10で、従来のパッチクランプ実験を行います。上皮単層のセルを選択し、頂端膜にピペットに近づきます。穏やかな吸引を適用することにより、ピペットと細胞膜との間に高抵抗シールを形成します。高抵抗ギガオームのシールが形成されると、保持電位でのギャップのないプロトコルは、関心のあるチャネルの監視活動のために起動する必要があります。 </li><li>ギガから店舗ギャップのない単一チャネル電流のデータΩは、その後の分析のために密封します。一般的にパッチクランプのセットアップ18に付属のソフトウェアパッケージを使用してチャネルのイベントを分析します。 Nはパッチ内のアクティブなチャネルの数を参照し、P oはチャネルの平均開口確率であるNPO法人としてのチャンネル活性を計算します。 注：30分以上のパッチクランプ実験で分離された嚢胞または細管を使用してください。 </li></ol>上皮細胞の細胞内カルシウム濃度の3レシオメトリック落射蛍光測定<ol><li> DMSOに溶解した5 mMのフラ - 2AMを使用してください。個々の500μlのコニカルチューブに小分け原液（約10μL）。最大6ヶ月間-20℃の冷凍庫で軽く、ストアから保護します。 </li><li> 5μMのFura-2 AM色素および0.0を含む：（145のNaCl、4.5のKCl、pHは7.35で2のMgCl 2、2のCaCl 2および10 HEPES mMの中で）、PSSで30〜40分間分離された嚢胞とスプリットオープン細管をインキュベート5％プルロニック酸アセトキシメチルエステルを分散するのに役立ちます。そのため、ローディングカクテルを含む3.5センチメートル皿に入れ組織は、光から保護し、室温でゆっくりと振とう機上でインキュベートします。 </li><li>インキュベーション後にPSSをきれいにし、さらに落射蛍光イメージングを実行するために顕微鏡下で組織を配置するために、メディアを含む変更のFura-2 AM。 </li><li>フィルターホイールを装備したCCDカメラと安定した光源（モノクロメータシステム）をオンにします（各フィルタの位置はフィルタが呼び出されるたびに、選択し、独自の減衰レベルに関連付けることができます）。 </li><li>明視野で組織を検索します。蛍光シグナルの検出に切り替えて、信号の飽和を回避するために、中性濃度フィルタ及びランプ電力を使用して光源の強度を調整します。 </li><li> 0.125ヘルツ以上の周波数で340/380 nmで励起レシオメトリックと組織試料中のFura-2 AMの蛍光を監視します。適切resolu 40×/ NA 1.3または類似の対物レンズを使用してくださいションイメージ。 </li><li>画像処理や計算のためのイメージシーケンスをインポートします。チャンネルを分割し、hyperstackのグレースケールモードを使用するようにしてください。興味のあるいくつかの領域を選択します（シングルシスト細胞または嚢胞性組織の選択された領域）であり、好ましいデータ解析ソフトウェアに、各チャネル（340および380 nm）のための強度値を計算します。各データポイントからバックグランド強度値を減算します。 </li><li>各時点についてのFura-2 AM 340〜380チャンネルの強度の比を計算します。プロットスキャッタ/各地域のの Ca 2+トランジェントのラインポイント時間の変更と計算平均/ SE値。 </li></ol>

The authors have nothing to disclose.

私たちは、ARPKDのマウス遺伝モデル由来嚢胞上皮単層に、ここで、従来のパッチクランプ法と落射蛍光カルシウムイメージングのアプリケーションを記述しました。プロトコルは、最も注意が嚢胞（プロトコルセクションのステップ1.5）の単離および電気生理学的研究に支払われるべき3つのステップで構成されています。これらのキーの手順では、広範囲の訓練と忍耐を必要とし、読者は一?...

イオンチャネルは、細胞の増殖および分化を含む多くの生理学的機能に重要な役割を果たしています。常染色体優性と劣性嚢胞腎疾患（ADPKDおよびARPKD、それぞれ）尿細管上皮細胞由来の腎臓の液体で満たされた嚢胞の開発によって特徴付けられる遺伝性疾患です。 ADPKDはpolycystins 1及び細胞増殖および分化の調節に関与する2は、膜タンパク質をコードするPKD1またはPKD2遺伝子の突然変異によって引き起こされます。それ自体で、またはPKD1との複合体としてPKD2もの Ca 2+ -permeable陽イオンチャネル1として機能します。 PKHD1をコードする遺伝子fibrocystin（細管形成および/ ​​または上皮の極性の維持に関与する繊毛関連受容体様タンパク質）の変異は、ARPKD 2の遺伝子原動力です。嚢胞の成長が乱れた増殖3,4、血管新生5、脱分化および極性の喪失を伴う複雑な現象であります尿細管細胞6-8の性。 嚢胞上皮の欠陥再吸収と増強分泌は、内腔と嚢胞拡大9,10内の流体の蓄積に貢献しています。障害フロー依存の[Ca 2+] iのシグナリングがまた、PKD 11-15の間に嚢胞形成にリンクされています。 ここでは、単一チャネル活性とPCKラットから分離された嚢胞性上皮単層における細胞内Ca 2+レベルのパッチクランプ測定のための適切な方法を説明します。このメソッドは、正常上皮 Na +チャネル（ENaC）10の活性を特徴づけるために私達によって適用し、[Ca 2+] iのの Ca 2+ -permeable TRPV4とプリンシグナリングカスケード13によって誘導されたプロセスを依存しました。 これらの研究では、PCKラット、PKHD1遺伝子における自然突然変異によって引き起こさARPKDのモデルを使用しました。 PCK株はoriginallましたスプラーグ-ドーリー（SD）ラットに由来するY 16それによってSDラットをPCK株と比較するための適切なコントロールとして使用されています。その結果、同じPCKラットから単離されたSDラットのネフロンセグメントと非拡張集合管の両方が、嚢胞上皮での実験のための2つの異なる比較群として機能することができます。

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		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Fura-2 AM</td>
			<td style="width:219px;">Life Technologies</td>
			<td style="width:183px;">F-14185</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Flou-8</td>
			<td style="width:219px;">AAT Bioquest</td>
			<td style="width:183px;">21091</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Poly-L-lysine</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:183px;">P4707</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Pluronic acid</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:183px;">F-68&#160;</td>
			<td style="width:333px;">solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Shaker</td>
			<td style="width:219px;">Boekel Scientific</td>
			<td style="width:183px;">260350</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Light source</td>
			<td style="width:219px;">Sutter Instrument Co</td>
			<td style="width:183px;">Lambda XL</td>
			<td style="width:333px;">with integrated shutter/filter wheel driver</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Neutral density filters</td>
			<td style="width:219px;">Nikon</td>
			<td style="width:183px;"></td>
			<td style="width:333px;">ND4, ND8</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Objective</td>
			<td style="width:219px;">Nikon</td>
			<td style="width:183px;">SFluo&#160;</td>
			<td style="width:333px;">40/1.3 DIC WD 0.22&#160;&#160; oil</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Camera</td>
			<td style="width:219px;">Andor Technologies</td>
			<td style="width:183px;">Zyla sCMOS</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:283px;">Nikon&#160; microscope (inverted)</td>
			<td style="width:219px;">Nikon</td>
			<td style="width:183px;">Nikon Eclipse TE2000-S</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Cover Glass</td>
			<td style="width:219px;">Thermo Scientific</td>
			<td style="width:183px;">6661B52</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Diamond pencil</td>
			<td style="width:219px;">Fisher Scientific</td>
			<td style="width:183px;">22268912</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Image acquisition software</td>
			<td style="width:219px;">Nikon</td>
			<td style="width:183px;">Nikon NIS-Elements&#160;</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:283px;">Image analysis software</td>
			<td style="width:219px;">ImageJ</td>
			<td style="width:183px;">http://imagej.nih.gov/</td>
			<td style="width:333px;">ND Utility plugin allows to import images in the native Nikon Instruments .nd2 format</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Recording/perfusion chamber</td>
			<td style="width:219px;">Warner Instruments</td>
			<td style="width:183px;">RC-26</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;"></td>
			<td style="width:219px;"></td>
			<td style="width:183px;"></td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Patch Clamp amplifier</td>
			<td style="width:219px;">Molecular Devices</td>
			<td style="width:183px;">MultiClamp 700B</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Data Acquisition System</td>
			<td style="width:219px;">Molecular Devices</td>
			<td style="width:183px;">Digidata 1440A</td>
			<td style="width:333px;">Axon Digidata&#174; System</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Low Pass Filter</td>
			<td style="width:219px;">Warner Instruments</td>
			<td style="width:183px;">LPF-8</td>
			<td style="width:333px;">8 pole Bessel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Borosilicate glass capillaries</td>
			<td style="width:219px;">World Precision Instruments</td>
			<td style="width:183px;">1B150F-4</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="29">
			<td height="29" style="height:29px;width:283px;">Micropipette Puller</td>
			<td style="width:219px;">Sutter Instrument Co</td>
			<td style="width:183px;">P-97</td>
			<td style="width:333px;">Flaming/Brown type micropipette puller</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Microforge</td>
			<td style="width:219px;">Narishige</td>
			<td style="width:183px;">MF-830</td>
			<td style="width:333px;">Japan</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Motorized Micromanipulator</td>
			<td style="width:219px;">Sutter Instrument Co</td>
			<td style="width:183px;">MP-225</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Inverted microscope</td>
			<td style="width:219px;">Nikon</td>
			<td style="width:183px;">Eclipse Ti</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Microvibration isolation table</td>
			<td style="width:219px;">TMC</td>
			<td style="width:183px;"></td>
			<td style="width:333px;">equipped with Faraday cage</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Multichannel valve perfusion system</td>
			<td style="width:219px;">AutoMake Scientific</td>
			<td style="width:183px;">Valve Bank II</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Recording/perfusion chamber</td>
			<td style="width:219px;">Warner Instruments</td>
			<td style="width:183px;">RC-26</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Software</td>
			<td style="width:219px;">Molecular Devices</td>
			<td style="width:183px;">pClamp 10 . 2</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;"></td>
			<td style="width:219px;"></td>
			<td style="width:183px;"></td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Temperature controlled surgical table&#160;</td>
			<td style="width:219px;">MCW core</td>
			<td style="width:183px;"></td>
			<td style="width:333px;">for rodents</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Binocular stereomicroscope</td>
			<td style="width:219px;">Nikon</td>
			<td style="width:183px;">SMZ745</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Syringe pump-based perfusion system</td>
			<td style="width:219px;">Harvard Apparatus</td>
			<td style="width:183px;"></td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">polyethylene tubing</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:183px;">PE50</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Isofluorane anesthesia</td>
			<td style="width:219px;"><a href="http://www.vetequip.com/">http://www.vetequip.com/</a></td>
			<td style="width:183px;">911103</td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;"></td>
			<td style="width:219px;"></td>
			<td style="width:183px;"></td>
			<td style="width:333px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Other basic reagents</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:183px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

implementing patch clamp and live fluorescence microscopy to monitor functional properties of freshly isolated pkd epithelium

多発性嚢胞腎嚢胞中の開始と拡大は尿細管細胞増殖の異常、管腔流体の蓄積および細胞外マトリックス形成を特徴とする複雑なプロセスです。イオンチャネルおよび細胞内カルシウムシグナル伝達の活性は、尿細管上皮の機能を決定する重要な生理学的パラメータです。我々は、新たに腎嚢胞から単離された上皮単層における細胞内Ca 2+レベルのパッチクランプ法と登録のイオンチャネル活性のリアルタイム観察に適した方法を開発しました。 PCKラット、常染色体劣性多発性嚢胞腎（ARPKD）の遺伝的モデルは、イオンチャネルおよびカルシウムフラックスの ex vivo分析のためにここで使用しました。ここで説明するには、PCKまたは通常のスプラーグドーリー（SD）ラットから嚢胞性単層と非拡張型細管を分離し、単一チャネル活性および細胞内Ca 2+動態を監視するために設計された、詳細なステップバイステップの手順です。この方法は、酵素処理を必要とし、新たに単離した上皮単層の本来の設定で分析を可能にしません。また、この技術は、細胞内カルシウムの変化に非常に敏感であり、正確な測定のために、高解像度の画像を生成します。最後に、単離された嚢胞上皮はさらに、抗体または染料を用いて、様々な生化学的アッセイのための一次培養および精製の調製物を染色するために使用することができます。

嚢胞形成の潜在的な関与のENaCは、PKDの進行22-25とARPKDマウスモデルおよび組織培養26-28における異常なナトリウム再吸収シグナリング破壊上皮成長因子（EGF）を観察し、いくつかの研究によって実証されています。例えば、Veizis らアミロライド感受性のNa +吸収をARPKD 29の非オルソロガスBPKマウスモデルからCD細胞において減少することを示しました。我?...

Watch this Scientific Journal Video about Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium at JoVE.com

Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium

尿細管上皮細胞で発現するイオンチャネルは、多発性嚢胞腎疾患の病理において重要な役割を果たす。ここでは、新たにげっ歯類の腎臓から単離された胆嚢上皮におけるパッチクランプ分析を行うために使用される実験プロトコルおよび細胞内カルシウムレベルの測定を説明します。

新たに単離したPKD上皮の機能的特性を監視するためにパッチクランプし、ライブ蛍光顕微鏡を実装

Cyst initiation and expansion during polycystic kidney disease is a complex process characterized by abnormalities in tubular cell proliferation, luminal ...

implementing-patch-clamp-live-fluorescence-microscopy-to-monitor

Research

JoVE Journal

Biology

9.7K ビュー.  Medical College of Wisconsin. 尿細管上皮細胞で発現するイオンチャネルは、多発性嚢胞腎疾患の病理において重要な役割を果たす。ここでは、新たにげっ歯類の腎臓から単離された胆嚢上皮におけるパッチクランプ分析を行うために使用される実験プロトコルおよび細胞内カルシウムレベルの測定を説明します。 

ビデオ: Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium

Methods for Patch Clamp Capacitance Recordings from the Calyx

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. Electrical recordings from the presynaptic terminal allow the measurement of action potentials, calcium channel currents, vesicle fusion (exocytosis) and subsequent membrane uptake (endocytosis). The fusion of vesicles containing neurotransmitter causes the vesicle membrane to be added to the cell membrane of the calyx. This increase in the amount of cell membrane is measured as an increase in capacitance. The subsequent reduction in capacitance indicates endocytosis, the process of membrane uptake or removal from the calyx membrane. Endocytosis, is necessary to maintain the structure of the calyx and it is also necessary to form vesicles that will be filled with neurotransmitter for future exocytosis events. Capacitance recordings at the calyx of Held have made it possible to directly and rapidly measure vesicular release and subsequent endocytosis in a mammalian CNS nerve terminal. In addition, the corresponding postsynaptic activity can be simultaneously measured by using paired recordings. Thus a complete picture of the presynaptic and postsynaptic electrical activity at a central nervous system synapse is achievable using this preparation. Here, the methods for slice preparation, morphological features for identification of calyces of Held, basic patch clamping techniques, and examples of capacitance recordings to measure exocytosis and endocytosis are presented.

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal.

がくからパッチクランプの静電容量の録音のための方法

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. ...

生物学

Patch Clamp Recording of Ion Channels Expressed in  Xenopus Oocytes

Since its development by Sakmann and Neher 1, 2, the patch clamp has become established as an extremely useful technique for electrophysiological measurement of single or multiple ion channels in cells. This technique can be applied to ion channels in both their native environment and expressed in heterologous cells, such as oocytes harvested from the African clawed frog, Xenopus laevis. Here, we describe the well-established technique of patch clamp recording from Xenopus oocytes. This technique is used to measure the properties of expressed ion channels either in populations (macropatch) or individually (single-channel recording). We focus on techniques to maximize the quality of oocyte preparation and seal generation. With all factors optimized, this technique gives a probability of successful seal generation over 90 percent. The process may be optimized differently by every researcher based on the factors he or she finds most important, and we present the approach that have lead to the greatest success in our hands.

This is intended as an introduction to patch clamp recording from Xenopus laevis oocytes. It covers vitelline membrane removal, formation of a gigaohm seal (gigaseal), and the optional conversion of the patch to the outside-out topology.

アフリカツメガエルの卵母細胞で発現イオンチャネルのパッチクランプ記録

Since its development by Sakmann and Neher 1, 2, the patch clamp has become established as an extremely useful technique for electrophysiological ...

Pressure-polishing Pipettes for Improved Patch-clamp Recording

Pressure-polishing is a method for shaping glass pipettes for patch-clamp recording. We first developed this method for fabricating pipettes suitable for recording from small (&lt;3 m) neuronal cell bodies. The basic principal is similar to glass-blowing and combines air pressure and heat to modify the shape of patch pipettes prepared by a conventional micropipette puller. It can be applied to so-called soft (soda lime) and hard (borosilicate) glasses. Generally speaking, pressure polishing can reduce pipette resistance by 25% without decreasing the diameter of the tip opening (Goodman and Lockery, 2000). It can be applied to virtually any type of glass and requires only the addition of a high-pressure valve and fitting to a microforge. This technique is essential for recording from ultrasmall cells (&lt;5 m) and can also improve single-channel recording by minimizing pipette resistance. The blunt shape is also useful for perforated-patch clamp recording since this tip shape results in a larger membrane bleb available for perforation.

This is a guide to modifying the shape of glass micropipettes. Specifically, by using heat and air pressure the taper is widened without increasing the tip opening, leading to lower pipette resistance. This is critical to obtain low noise recordings of small cells but is useful in many applications.

改善されたパッチクランプ記録のための圧力 - 研磨ピペット

Pressure-polishing is a method for shaping glass pipettes for patch-clamp recording.  We first developed this method for fabricating pipettes suitable for ...

Time-lapse Imaging of Mitosis After siRNA Transfection

Changes in cellular organization and chromosome dynamics that occur during mitosis are tightly coordinated to ensure accurate inheritance of genomic and cellular content. Hallmark events of mitosis, such as chromosome movement, can be readily tracked on an individual cell basis using time-lapse fluorescence microscopy of mammalian cell lines expressing specific GFP-tagged proteins. In combination with RNAi-based depletion, this can be a powerful method for pinpointing the stage(s) of mitosis where defects occur after levels of a particular protein have been lowered. In this protocol, we present a basic method for assessing the effect of depleting a potential mitotic regulatory protein on the timing of mitosis. Cells are transfected with siRNA, placed in a stage-top incubation chamber, and imaged using an automated fluorescence microscope. We describe how to use software to set up a time-lapse experiment, how to process the image sequences to make either still-image montages or movies, and how to quantify and analyze the timing of mitotic stages using a cell-line expressing mCherry-tagged histone H2B. Finally, we discuss important considerations for designing a time-lapse experiment. This strategy is complementary to other approaches and offers the advantages of 1) sensitivity to changes in kinetics that might not be observed when looking at cells as a population and 2) analysis of mitosis without the need to synchronize the cell cycle using drug treatments. The visual information from such imaging experiments not only allows the sub-stages of mitosis to be assessed, but can also provide unexpected insight that would not be apparent from cell cycle analysis by FACS.

Here we describe a basic protocol to image and quantify the mitotic timing of live mammalian tissue culture cells after siRNA transfection.

siRNAトランスフェクション後の有糸分裂のタイムラプスイメージング

Changes in cellular organization and chromosome dynamics that occur during mitosis are tightly coordinated to ensure accurate inheritance of genomic and ...

Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber

Store operated Ca2+ entry (SOCE), earlier termed capacitative Ca2+ entry, is a tightly regulated mechanism for influx of extracellular Ca2+ into cells to replenish depleted endoplasmic reticulum (ER) or sarcoplasmic reticulum (SR) Ca2+ stores1,2. Since Ca2+ is a ubiquitous second messenger, it is not surprising to see that SOCE plays important roles in a variety of cellular processes, including proliferation, apoptosis, gene transcription and motility. Due to its wide occurrence in nearly all cell types, including epithelial cells and skeletal muscles, this pathway has received great interest3,4. However, the heterogeneity of SOCE characteristics in different cell types and the physiological function are still not clear5-7.
The functional channel properties of SOCE can be revealed by patch-clamp studies, whereas a large body of knowledge about this pathway has been gained by fluorescence-based intracellular Ca2+ measurements because of its convenience and feasibility for high-throughput screening. The objective of this report is to summarize a few fluorescence-based methods to measure the activation of SOCE in monolayer cells, suspended cells and muscle fibers5,8-10. The most commonly used of these fluorescence methods is to directly monitor the dynamics of intracellular Ca2+ using the ratio of F340nm and F380nm (510 nm for emission wavelength) of the ratiometric Ca2+ indicator Fura-2. To isolate the activity of unidirectional SOCE from intracellular Ca2+ release and Ca2+ extrusion, a Mn2+ quenching assay is frequently used. Mn2+ is known to be able to permeate into cells via SOCE while it is impervious to the surface membrane extrusion processes or to ER uptake by Ca2+ pumps due to its very high affinity with Fura-2. As a result, the quenching of Fura-2 fluorescence induced by the entry of extracellular Mn2+ into the cells represents a measurement of activity of SOCE9. Ratiometric measurement and the Mn+2 quenching assays can be performed on a cuvette-based spectrofluorometer in a cell population mode or in a microscope-based system to visualize single cells. The advantage of single cell measurements is that individual cells subjected to gene manipulations can be selected using GFP or RFP reporters, allowing studies in genetically modified or mutated cells. The spatiotemporal characteristics of SOCE in structurally specialized skeletal muscle can be achieved in skinned muscle fibers by simultaneously monitoring the fluorescence of two low affinity Ca2+ indicators targeted to specific compartments of the muscle fiber, such as Fluo-5N in the SR and Rhod-5N in the transverse tubules9,11,12.

The extent of store-operated Ca2+ entry (SOCE) can be monitored using fluorescent Ca2+ indicators. Mn2+ quenching of such indicators assays SOCE in cultured cells and skeletal muscle fibers. A technique allowing spatial and temporal resolution of SOCE by confocal imaging of mechanically skinned muscle fibers is also described.

生細胞におけるストア作動性カルシウムエントリの蛍光ベースの測定：培養癌細胞から骨格筋線維に

Store operated Ca2+ entry (SOCE), earlier termed capacitative Ca2+ entry, is a tightly regulated mechanism for influx of extracellular Ca2+ into cells to ...

Quantitative Live Cell Fluorescence-microscopy Analysis of Fission Yeast

Several microscopy techniques are available today that can detect a specific protein within the cell. During the last decade live cell imaging using fluorochromes like Green Fluorescent Protein (GFP) directly attached to the protein of interest has become increasingly popular 1. Using GFP and similar fluorochromes the subcellular localisations and movements of proteins can be detected in a fluorescent microscope. Moreover, also the subnuclear localisation of a certain region of a chromosome can be studied using this technique. GFP is fused to the Lac Repressor protein (LacR) and ectopically expressed in the cell where tandem repeats of the lacO sequence has been inserted into the region of interest on the chromosome2. The LacR-GFP will bind to the lacO repeats and that area of the genome will be visible as a green dot in the fluorescence microscope. Yeast is especially suited for this type of manipulation since homologous recombination is very efficient and thereby enables targeted integration of the lacO repeats and engineered fusion proteins with GFP 3. Here we describe a quantitative method for live cell analysis of fission yeast. Additional protocols for live cell analysis of fission yeast can be found, for example on how to make a movie of the meiotic chromosomal behaviour 4. In this particular experiment we focus on subnuclear organisation and how it is affected during gene induction. We have labelled a gene cluster, named Chr1, by the introduction of lacO binding sites in the vicinity of the genes. The gene cluster is enriched for genes that are induced early during nitrogen starvation of fission yeast 5. In the strain the nuclear membrane (NM) is labelled by the attachment of mCherry to the NM protein Cut11 giving rise to a red fluorescent signal. The Spindle Pole body (SPB) compound Sid4 is fused to Red Fluorescent Protein (Sid4-mRFP) 6. In vegetatively growing yeast cells the centromeres are always attached to the SPB that is embedded in the NM 7. The SPB is identified as a large round structure in the NM. By imaging before and 20 minutes after depletion of the nitrogen source we can determine the distance between the gene cluster (GFP) and the NM/SPB. The mean or median distances before and after nitrogen depletion are compared and we can thus quantify whether or not there is a shift in subcellular localisation of the gene cluster after nitrogen depletion.

The fission yeast, Schizosaccharomyces pombe, is a good model system to study basic cellular processes. Here we describe a method to perform quantitative live cell analysis of fission yeast. In this particular experiment we focus on organisation of the genome within the cell nucleus, but the method can also be used to study cytosolic factors.

分裂酵母の定量的なライブセル蛍光-顕微鏡解析

Several microscopy techniques are available today that can detect a specific protein within the cell. During the last decade live cell imaging using ...

Giant Liposome Preparation for Imaging and Patch-Clamp Electrophysiology

The reconstitution of ion channels into chemically defined lipid membranes for electrophysiological recording has been a powerful technique to identify and explore the function of these important proteins. However, classical preparations, such as planar bilayers, limit the manipulations and experiments that can be performed on the reconstituted channel and its membrane environment. The more cell-like structure of giant liposomes permits traditional patch-clamp experiments without sacrificing control of the lipid environment.
Electroformation is an efficient mean to produce giant liposomes &gt;10 &mu;m in diameter which relies on the application of alternating voltage to a thin, ordered lipid film deposited on an electrode surface. However, since the classical protocol calls for the lipids to be deposited from organic solvents, it is not compatible with less robust membrane proteins like ion channels and must be modified. Recently, protocols have been developed to electroform giant liposomes from partially dehydrated small liposomes, which we have adapted to protein-containing liposomes in our laboratory.
We present here the background, equipment, techniques, and pitfalls of electroformation of giant liposomes from small liposome dispersions. We begin with the classic protocol, which should be mastered first before attempting the more challenging protocols that follow. We demonstrate the process of controlled partial dehydration of small liposomes using vapor equilibrium with saturated salt solutions. Finally, we demonstrate the process of electroformation itself. We will describe simple, inexpensive equipment that can be made in-house to produce high-quality liposomes, and describe visual inspection of the preparation at each stage to ensure the best results.

Reconstituting functional membrane proteins into giant liposomes of defined composition is a powerful approach when combined with patch-clamp electrophysiology. However, conventional giant liposome production may be incompatible with protein stability. We describe protocols for producing giant liposomes from pure lipids or small liposomes containing ion channels.

イメージングとパッチクランプ電気生理学用ジャイアントリポソーム製剤

The reconstitution of ion channels into chemically defined lipid membranes for electrophysiological recording has been a powerful technique to identify ...

One-channel Cell-attached Patch-clamp Recording

Ion channel proteins are universal devices for fast communication across biological membranes. The temporal signature of the ionic flux they generate depends on properties intrinsic to each channel protein as well as the mechanism by which it is generated and controlled and represents an important area of current research. Information about the operational dynamics of ion channel proteins can be obtained by observing long stretches of current produced by a single molecule. Described here is a protocol for obtaining one-channel cell-attached patch-clamp current recordings for a ligand gated ion channel, the NMDA receptor, expressed heterologously in HEK293 cells or natively in cortical neurons. Also provided are instructions on how to adapt the method to other ion channels of interest by presenting the example of the mechano-sensitive channel PIEZO1. This method can provide data regarding the channel&#8217;s conductance properties and the temporal sequence of open-closed conformations that make up the channel&#8217;s activation mechanism, thus helping to understand their functions in health and disease.

Described here is a procedure for obtaining long stretches of current recording from one ion channel with the cell-attached patch-clamp technique. This method allows for observing, in real time, the pattern of open-close channel conformations that underlie the biological signal. These data inform about channel properties in undisturbed biological membranes.

一チャネルセル付パッチクランプ法

Ion channel proteins are universal devices for fast communication across biological membranes. The temporal signature of the ionic flux they generate ...

Reconstitution of a Transmembrane Protein, the Voltage-gated Ion Channel, KvAP, into Giant Unilamellar Vesicles for Microscopy and Patch Clamp Studies

Giant Unilamellar Vesicles (GUVs) are a popular biomimetic system for studying membrane associated phenomena. However, commonly used protocols to grow GUVs must be modified in order to form GUVs containing functional transmembrane proteins. This article describes two dehydration-rehydration methods &#8212; electroformation and gel-assisted swelling &#8212; to form GUVs containing the voltage-gated potassium channel, KvAP. In both methods, a solution of protein-containing small unilamellar vesicles is partially dehydrated to form a stack of membranes, which is then allowed to swell in a rehydration buffer. For the electroformation method, the film is deposited on platinum electrodes so that an AC field can be applied during film rehydration. In contrast, the gel-assisted swelling method uses an agarose gel substrate to enhance film rehydration. Both methods can produce GUVs in low (e.g., 5 mM) and physiological (e.g., 100 mM) salt concentrations. The resulting GUVs are characterized via fluorescence microscopy, and the function of reconstituted channels measured using the inside-out patch-clamp configuration. While swelling in the presence of an alternating electric field (electroformation) gives a high yield of defect-free GUVs, the gel-assisted swelling method produces a more homogeneous protein distribution and requires no special equipment.

The reconstitution of the transmembrane protein, KvAP, into giant unilamellar vesicles (GUVs) is demonstrated for two dehydration-rehydration methods &#8212; electroformation, and gel-assisted swelling. In both methods, small unilamellar vesicles containing the protein are fused together to form GUVs that can then be studied by fluorescence microscopy and patch-clamp electrophysiology.

膜貫通タンパク質の再構成、顕微鏡およびパッチクランプ研究のための巨大単膜小胞への電位依存性イオンチャネル、KvAP、

Giant Unilamellar Vesicles (GUVs) are a popular biomimetic system for studying membrane associated phenomena. However, commonly used protocols to grow ...

Single-channel Analysis and Calcium Imaging in the Podocytes of the Freshly Isolated Glomeruli

Podocytes (renal glomerular epithelial cells) are known to regulate glomerular permeability and maintain glomerular structure; a key role for these cells in the pathogenesis of various renal diseases has been established since podocyte injury leads to proteinuria and foot process effacement. It was previously reported that various endogenous agents may cause a dramatic overload in intracellular Ca2+ concentration in podocytes, presumably leading to albuminuria, and this likely occurs via calcium-conducting ion channels. Therefore, it appeared important to study calcium handling in the podocytes both under normal conditions and in various pathological states. However, available experimental approaches have remained somewhat limited to cultured and transfected cells. Although they represent a good basic model for such studies, they are essentially extracted from the native environment of the glomerulus. Here we describe the methodology of studying podocytes as a part of the freshly isolated whole glomerulus. This preparation retains the functional potential of the podocytes, which are still attached to the capillaries; therefore, podocytes remain in the environment that conserves the major parts of the glomeruli filtration apparatus. The present manuscript elaborates on two experimental approaches that allow 1) real-time detection of calcium concentration changes with the help of ratiometric confocal fluorescence microscopy, and 2) the recording of the single ion channels activity in the podocytes of the freshly isolated glomeruli. These methodologies utilize the advantages of the native environment of the glomerulus that enable researchers to resolve acute changes in the intracellular calcium handling in response to applications of various agents, measure basal concentration of calcium within the cells (for instance, to evaluate disease progression), and assess and manipulate calcium conductance at the level of single ion channels.

Changes in the intracellular calcium levels in the podocytes are one of the most important means to control the filtration function of glomeruli. Here we explain a high-throughput approach that allows detection of real-time calcium handling and single ion channels activity in the podocytes of the freshly isolated glomeruli.

新たに単離した糸球体の足細胞における単一チャネル分析とカルシウムイメージング

Podocytes (renal glomerular epithelial cells) are known to regulate glomerular permeability and maintain glomerular structure; a key role for these cells ...