Gli autori desiderano ringraziare il signor Richard Zink e Todd Wiernicki per la formazione metodologica e di orientamento dosaggio. Ringraziamo anche Giovanni Paolo Spence un&#39;attenta lettura e proposte editoriali. Questo lavoro è stato sostenuto dal National Institute of Health MH 060.397, Brain and Behavior Research Foundation, e Eli Lilly and Company attraverso il Research Award Program Lilly (LRAP).

1. Espansione e crioconservazione delle cellule Assay pronti <ol><li> Cultura CHO-K1-DRD 2L (CHO-D 2L) le cellule su una cella piatto 15 centimetri 2 cultura dei media F12 di Ham integrato con 1.0 mM L-glutammina, 800 mg / mL G418, 300 mg / igromicina ml, 100 U / ml penicillina, 100 pg / ml streptomicina, e siero bovino fetale al 10% (FBS). </li><li> Incubare le cellule a 37 ° C in un incubatore umidificato con 5% di CO 2 fino a quando le cellule sono 90-95% confluenti. Lavare le cellule con 10 microlitri tampone fosfato isotonico (PBS), e raccogliere le cellule aggiungendo 3 ml di tampone di dissociazione cellulare per 5 min a 37 ° C. Risospendere le cellule con 12 ml di media cultura e contare le celle utilizzando trypan blu. </li><li> Centrifugare la sospensione cellulare a 500 xg per 5 min a temperatura ambiente. Aspirare il supernatante e risospendere il pellet cellulare in 5 ml di mezzi di congelamento (10% dimetilsolfossido, 90% FBS). Diluire la sospensione cellulare per raggiungere la concentrazione cellulare desiderata (ad esempio 1-20 x 10 6 cellule / ml). </li><li> Aliquota 1,0 ml di soluzione di cella per ogni esageratamente. Incubare le cryovials in un contenitore cella di congelamento a -80 ° C per una notte. Trasferire le cryovials ad un serbatoio di liquido N 2 per conservazione a lungo termine. </li></ol> 2. Placcatura del saggio Cellule pronte (e Reverse Transfezione Option) <ol><li> Rapidamente scongelare un esageratamente congelata di cellule in un bagno d&#39;acqua a 37 °. Una volta che le cellule vengono scongelate, trasferire le cellule in una provetta da 15 ml contenente 9 ml di Opti-MEM, e mescolare per inversione 3-5x. </li><li> Centrifugare le cellule a 500 xg per 5 min a temperatura ambiente. Aspirare il surnatante e sospendere nuovamente le cellule in 1 ml Opti-MEM. </li><li> Contare le cellule utilizzando trypan blu per determinare la vitalità cellulare e diluire le cellule vitali, se necessario (ad es. 3 x 10 5 cellule / ml concentrazione) inOpti-MEM. La tavola 10 microlitri / pozzetto di cellule di una coltura tissutale trattata piastra a 384 pozzetti usando una pipetta multicanale. </li><li> Effettuare diluizioni seriali di cAMP in Opti-MEM per generare una curva standard per stimare la produzione di cAMP da parte delle cellule (secondo le manifatture raccomandazioni - vedere la sezione 7). Aggiungere 10 microlitri / pozzetto delle norme cAMP alla piastra Nota:. Un&#39;unica curva standard può essere preparato su una piastra separata o pozzi in bianco su una delle piastre di saggio. </li><li> Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente, e incubare a 37 ° C in un incubatore umidificato con 5% di CO 2 per 1 ora. </li></ol> 3. Invertire la trasfezione di siRNA Opzione * Questa sezione è facoltativa e pertinente alla figura 3. <ol><li> Preparare una soluzione di siRNA in DDH RNase-free 2 O (ad esempio 0,4 pmol / ml). Aggiungere 5 microlitri a singoli pozzetti della piastra a 384 pozzetti, e centrifugare la piastra a 100 xg per 15 SEc a temperatura ambiente. </li><li> Diluire Lipofectamine 2000 Opti-MEM di un fattore 0.006 (es aggiungere 6 ml di Lipofectamine 2000 a 1000 ml di Opti-MEM), e mescolare pipettando su e giù. </li><li> Incubare la soluzione Lipofectamine 2000/Opti-MEM per 5 min a temperatura ambiente. Aggiungere 5 ml di soluzione diluita Lipofectamine 2000/Opti-MEM a singoli pozzetti della piastra a 384 pozzetti che contiene già siRNA. Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente. </li><li> Incubare la piastra per 30 minuti a temperatura ambiente. </li><li> Saggio Piatto cellule pronte come descritto in precedenza (sezione 2). Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente. </li><li> Ritorno piastra di saggio di incubatore umidificato a 37 ° (CO 5% 2) C per 48-96 ore, come determinato per il gene targeting abbattere (vedi la discussione). </li></ol> 4. Piccolo Screening Molecola <ol><li> Diluire il farmaco di interesse (es. inibitori. Piccole molecole) in Opti-MEM a 6x le concentrazioni finali desiderati. Diluizioni seriali possono essere completate con pipette a mano o una stazione di gestione dei liquidi. </li><li> Aggiungere 2,5 ml / pozzetto di composto di prova o tampone contenente veicolo (ad es DMSO) al lato dei pozzetti usando una pipetta multicanale. </li><li> Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente (incubazione è opzionale). </li></ol> 5. Persistente Agonista Trattamento <ol><li> Preparare una 600 nm (per esempio. 6 volte la concentrazione finale desiderata di 100 nm) soluzione quinpirole in Opti-MEM. </li><li> Aggiungere 2,5 ml / pozzetto di soluzione quinpirole 600 nM al lato dei pozzetti usando una pipetta multicanale. </li><li> Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente, e incubare a 37 ° C in un incubatore umidificato con 5% di CO 2 per 2 h. </li></ol> 6. La stimolazione di cAMP Accumulation <ol><li> Durante l&#39;incubazione 2 ore, prepara le stimulatisulla soluzione Opti-MEM. La soluzione di stimolazione è composto da 40 mM forskolina, 2 mM 3-isobutil-1-methyxanthine (IBMX), e 4 mM spiperone (tutte le concentrazioni nel passaggio 6 sono 4x la concentrazione finale desiderata). </li><li> Aggiungere 5 microlitri / pozzetto della soluzione stimolazione al lato dei pozzetti usando una pipetta multicanale. </li><li> Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente, e incubare a temperatura ambiente per 1 ora. </li></ol> 7. Tempra e stima di cAMP Accumulation <ol><li> Produzione di cAMP da parte delle cellule è misurata utilizzando il kit dinamico 2 cAMP secondo le istruzioni del produttore. In breve, ricostituire anti-cAMP-criptato e cAMP-d2 in acqua distillata. Congelare aliquote a -20 ° C per la conservazione a breve termine. </li><li> Diluire un&#39;aliquota di anti-cAMP-criptato e un&#39;aliquota di cAMP-d2 separatamente nel tampone di lisi secondo le istruzioni del produttore per rendere soluzioni di lavoro. </li><li> Lagg 10 microlitri / pozzetto della soluzione di lavoro anti-cAMP-criptato e 10 microlitri / pozzetto della soluzione di lavoro cAMP-d2 alla piastra a 384 pozzetti usando una pipetta multicanale. </li><li> Centrifugare la piastra a 100 xg per 15 secondi a temperatura ambiente, e incubare a temperatura ambiente per 1 ora. </li><li> Leggere la piastra in un lettore di piastre a fluorescenza (impostazione scala automatica della sensibilità), utilizzando una eccitazione di 337 nm, e misurare le emissioni a 620 nm e 665 nm per manufatti istruzioni. </li><li> Applicare analisi raziometrica per valutare curva standard cAMP produce per le istruzioni. Utilizzando i valori risultanti, estrapolare l&#39;accumulo di cAMP stima nei pozzetti utilizzando il software di analisi dei dati. </li></ol>

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Nel tentativo di facilitare gli studi di sensibilizzazione eterologa, abbiamo ampiamente modificato il nostro metodo precedente realizzare una struttura snella &quot;mix e leggere&quot; formato che è modificabile a high-throughput screening e il meccanismo di esame azione. Le principali modifiche al nostro protocollo possono essere riassunti come segue: 1) l&#39;uso di cellule crioconservate come reagenti di saggio &quot;pronto&quot;, 2) la miniaturizzazione del dosaggio in 384 pozzetti, e 3) l&#39;utilizzazione della ...

Un ciclasi adattativo (AC) di segnalazione di risposta noto come-eterologo o super-sensibilizzazione è stato scoperto nel laboratorio del premio Nobel, il dottor Marshall Nirenberg. Il Dott. Nirenberg proposto che l&#39;aumento della reattività AC osservata dopo l&#39;attivazione dei recettori oppioidi δ cronica era un meccanismo coinvolto nella tolleranza e dipendenza da oppiacei 1. Oltre ai recettori oppioidi δ cronica, questa risposta neuroadaptive di segnalazione AC si verifica anche dopo l&#39;attivazione persistente di diversi altri Gαi / o recettori accoppiati a 2. In particolare, molti di questi recettori sono associati con dolore, disturbi neuropsichiatrici e neurologici, e comprendono μ / κ oppioidi, D 2/4 dopamina, 5HT 1A, e M 2/4 recettori muscarinici 2. Oltre ai risultati del Dott. Nirenberg, un grande corpo di evidenze esiste collega sensibilizzazione della segnalazione AC all&#39;attivazione cronica dei recettori oppioidi sia <em&gt; in vitro e in vivo 3-7. Sensibilizzazione di AC è stata anche associata con una varietà di malattie che coinvolgono i recettori dopaminergici D 2-come compreso la schizofrenia e il morbo di Parkinson (per una rassegna vedi riferimento 2). Nonostante l&#39;importanza potenziale di sensibilizzazione, il meccanismo preciso (s) associata a persistente / attivazione del recettore Gαi o accoppiato, che porta ad una maggiore reattività AC rimane in gran parte sconosciuta. Questi studi forniscono il razionale per l&#39;esame dei meccanismi di sensibilizzazione della ciclasi come un importante obiettivo neurobiologica. Analogamente, la rilevanza fisiologica di AC segnalazione 8 e l&#39;importanza che le singole isoforme AC tengono in questa risposta adattativa dovrebbero essere riconosciuti 2,9,10. Nel contesto della nostra ricerca, le caratteristiche generali associati sensibilizzazione eterologa delle isoforme ricombinanti di AC paralleli tali caratteristiche described per studiare le isoforme endogeni di AC. In particolare, la ricerca precedente ha scoperto che l&#39;attivazione di Gαi / o proteine ​​e subunità successivo rilascio / riassestamento βγ sono requisiti importanti per il recettore indotta sensibilizzazione di tutte le isoforme AC. Inoltre, diversi studi suggeriscono che la segnalazione di proteine ​​chinasi e subunità Gβγ sono coinvolti nella sensibilizzazione 2,11-13. AC individuali mostrano anche i modelli di sensibilizzazione uniche e distinte 12. Per esempio, l&#39;esposizione persistente di D 2 recettori agonisti è associata con sensibilizzazione di AC1 e AC8 di Ca 2 + / calmodulina stimolazione 14,15, mentre la strettamente correlata AC3 non è sensibilizzata 2. AC2, AC4 e AC7 sono strettamente correlati, però, solo l&#39;attività AC2 PKC-stimolata è robusto sensibilizzato dopo una prolungata esposizione di D 2 recettori agli agonisti 7,14,16,17. Inoltre, AC5 e AC6 mostrano una marcata grado di hetersensibilizzazione ologous a gas e forskolina stimolata cAMP accumulo a seguito di attivazione dei recettori D2 14,18-20, ma sembrano differire nella loro esigenza di Gβγ subunità-AC INTERAZIONI 21. Sebbene la maggior parte degli studi di sensibilizzazione AC hanno utilizzato linee cellulari modello (ad esempio cellule HEK293 che esprimono le singole isoforme di AC), sembra che questi risultati si traducono in modelli cellulari neuronali nativi 4,22. Più recentemente, gli effetti della isoforma AC selettivi piccole molecole inibitrici identificati in cellule HEK293 esprimenti isoforme CA possono anche essere tradotti in studi comportamentali in vivo 23. La mancanza di un meccanismo molecolare identificato per la sensibilizzazione eterologa probabilmente riflette la complessità della risposta adattativa nonché le uniche proprietà regolazione individuale isoforme AC 12. Dipanare tale complessità è ulteriormente complicata dall&#39;utilizzo di ingombrante metodologia tCappello ha limitato ricercatori accademici da impiegare approcci imparziali. Ad esempio, i nostri precedenti studi meccanicistici comportato l&#39;utilizzo di modelli cellulari continuamente coltivate con 24 - e 48-ben formato coltura di tessuti 15. Cellule in coltura erano tipicamente coltivate per 48 ore e quindi sottoposti a trattamento farmacologico con agonisti (2-18 ore) seguito da una serie di lavaggi cellulari e incubazione (Figura 1). Protocolli accumulo di cAMP specifico AC-isoforma erano poi impiegato seguita dalla misurazione di accumulo di cAMP utilizzando un laborioso e richiede tempo [3 H] cAMP metodologia 15,24 vincolante. La durata dall&#39;inizio alla fine di ciascun saggio generalmente richiesto un totale di quattro o cinque giorni da placcatura cella per l&#39;analisi dei dati (Figura 1). L&#39;applicazione di nuove tecnologie e l&#39;automazione ha portato a miglioramenti marcati per gli studi di sensibilizzazione in ambiente industriale e HTS centro. Ad esempio, un gruppo di lavoro con il Centro Nazionale per Chemical Genomics ha riportato una due giorni HTS procedura di analisi per l&#39;identificazione di piccole molecole inibitrici di μ recettori oppioidi sensibilizzazione indotta in formato 1.536-ben 25. Il presente articolo descrive i nostri sforzi per sviluppare un test HTS per studi di sensibilizzazione eterologa utilizzando tecnologie che sono disponibili presso la maggior parte degli istituti di ricerca universitari. Questa strategia è stata realizzata incorporando l&#39;uso di cellule crioconservati da modelli cellulari eterologhi che esprime il recettore dopaminergico D 2 in combinazione con endogeni o singoli ricombinanti isoforme ciclasi (CHO-D 2L o HEK-AC6 / D 2 L). Per migliorare il nostro rendimento, abbiamo ridisegnato la nostra sensibilizzazione test ben 48 (ca.&gt; 20 passi oltre 4-5 giorni) per un periodo di cinque step, test solo giorno in formato 384-bene che era essenzialmente &quot;mix e leggere&quot;. Il nuovo formato utilizza un tempo omogeneo disponibile in commercio fluorescenza risolta (HTRF) test per misurare cAMP accumulation in cellule intatte con un lettore di piastra a più modalità. Il test è robusto e suscettibili di proiezione piccola molecola, e può essere efficacemente applicata a screening per inibitori di sensibilizzazione eterologa. Inoltre, forniamo i dati che permettono l&#39;uso di questo test con trasfezione inversione di siRNA a una vasta libreria di siRNA lo screening mirati o del genoma con solo una piccola modifica per l&#39;impostazione generale.

<table border="0" cellpadding="0" cellspacing="0" width="695">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">CHO-K1-DRD2L cells</td>
			<td style="width:144px;">DiscoveRx</td>
			<td style="width:148px;">930579C2</td>
			<td style="width:199px;"></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Ham&#8217;s F12 media</td>
			<td style="width:144px;">VWR</td>
			<td style="width:148px;">SH30026fs</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Fetal Bovine Serum</td>
			<td style="width:144px;">VWR</td>
			<td style="width:148px;">SH3007003</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">G418</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">A1720</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Hygromycin</td>
			<td style="width:144px;">Fisher</td>
			<td style="width:148px;">50-230-5556</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Penicillin/ streptomycin</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:148px;">15070063</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">15 cm dishes</td>
			<td style="width:144px;">BD Falcon</td>
			<td style="width:148px;">353025</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">DMSO</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">D2650</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Cell dissociation buffer</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:148px;">13150016</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Phosphate Buffered Saline</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:148px;">10010-049</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Cryovials</td>
			<td style="width:144px;">Fisher</td>
			<td style="width:148px;">976171</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Opti-MEM</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:148px;">31985070</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">TC treated 384 well plates</td>
			<td style="width:144px;">Perkin-Elmer</td>
			<td style="width:148px;">6007688</td>
			<td></td>
		</tr>
		<tr height="66">
			<td height="66" style="height:66px;width:205px;">HTRF cAMP Dynamic 2 kit</td>
			<td style="width:144px;">Cisbio Bioassays</td>
			<td style="width:148px;">62AM4PEB</td>
			<td style="width:199px;">http://www.htrf.com/camp-cell-based-assay</td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Synergy 4</td>
			<td style="width:144px;">Biotek</td>
			<td style="width:148px;">H4MLFPTAD</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Prism 6</td>
			<td style="width:144px;">GraphPad Software</td>
			<td style="width:148px;">NA</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">3-Isobutyl-1-methylxanthine</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">I5879</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">(&#177;)Quinpirole</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">Q111</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Spiperone</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">S7395</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Clozapine</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">C6305</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Haloperidol</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">H1512</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">S-(-)Sulpiride</td>
			<td style="width:144px;">Sigma</td>
			<td style="width:148px;">S112</td>
			<td></td>
		</tr>
		<tr height="55">
			<td height="55" style="height:55px;width:205px;">Lipofectamine2000 transfection reagent</td>
			<td style="width:144px;">Invitrogen</td>
			<td style="width:148px;">11668019</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Trypan blue</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:148px;">T10282</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Water, DNase, RNase-free</td>
			<td style="width:144px;">MP Biomedicals</td>
			<td style="width:148px;">821739</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Gas siRNA</td>
			<td style="width:144px;">Dharmacon</td>
			<td style="width:148px;">custom siRNA</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">Non-targeting siRNA control</td>
			<td style="width:144px;">Dharmacon</td>
			<td style="width:148px;">D-001206-14-20</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:205px;">siGlo Red</td>
			<td style="width:144px;">Dharmacon</td>
			<td style="width:148px;">D-001630-02</td>
			<td></td>
		</tr>
	</tbody>
</table>

drug-induced sensitization of adenylyl cyclase: assay streamlining and miniaturization for small molecule and sirna screening applications

Sensibilizzazione di adenilato ciclasi (AC) segnalazione è stata implicata in una varietà di disturbi neuropsichiatrici e neurologici compreso abuso di sostanze e il morbo di Parkinson. L&#39;attivazione acuta di Gαi / recettori o-linked inibisce l&#39;attività AC, mentre l&#39;attivazione persistente di questi recettori provoca sensibilizzazione eterologa di AC e aumento dei livelli di cAMP intracellulare. Studi precedenti hanno dimostrato che questo miglioramento di reattività AC è osservato sia in vitro che in vivo in seguito all&#39;attivazione cronica di diversi tipi di recettori / O-linked Gαi compresi D 2 della dopamina e recettori oppioidi μ. Sebbene sensibilizzazione eterologa di AC è stata segnalata per la prima di quattro decenni fa, il meccanismo (s) che sono alla base di questo fenomeno restano in gran parte sconosciute. La mancanza di dati meccanicistici presumibilmente riflette la complessità di questa risposta adattativa, suggerendo che gli approcci nonbiased potrebbero aiutare a identificarezione delle vie molecolari coinvolti nella sensibilizzazione eterologa di AC. Studi precedenti hanno implicato chinasi e segnalazione Gbγ come componenti che regolano la sensibilizzazione eterologa di AC sovrapposizione. Per identificare gli obiettivi sovrapposti unico e aggiuntivi connessi con la sensibilizzazione di AC, lo sviluppo e la validazione di una soluzione scalabile test cAMP sensibilizzazione è necessaria per una maggiore produttività. Approcci precedenti per studiare sensibilizzazione sono generalmente ingombranti coinvolge cellulare continua cultura manutenzione nonché una complessa metodologia per misurare l&#39;accumulo di cAMP che coinvolge più fasi di lavaggio. Pertanto, lo sviluppo di un saggio basato su cellule robusto che può essere utilizzato per lo screening ad alto rendimento (HTS) in un formato ben 384 facilitare studi futuri. Utilizzando due modelli cellulari D 2 del recettore della dopamina (ad esempio. CHO-D 2L e HEK-AC6 / D 2L), abbiamo trasformato il nostro saggio di sensibilizzazione a 48 pozzetti (&gt; 20 gradini 4-5 giorni) per un periodo di cinque-step, unico dosaggio giorno in formato 384-bene. Questo nuovo formato è suscettibile di proiezione piccola molecola, e ci dimostrano che questo motivo test può anche essere facilmente utilizzato per la trasfezione inversione di siRNA in previsione di uno screening della libreria siRNA mirati.

Parte I. Lo sviluppo di una 384 ben eterologa saggio di sensibilizzazione per l&#39;identificazione di piccole molecole inibitrici utilizzando un modello cellulare disponibile in commercio. Per studiare sensibilizzazione eterologa in un modello cellulare, abbiamo fatto una serie di miglioramenti che ci hanno permesso di snellire l&#39;analisi in un formato &quot;mix e leggere&quot;. Varie modifiche chiave sono evidenziati di seguito, e sono descritti in maggior dettaglio nel...

Watch this Scientific Journal Video about Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications at JoVE.com

Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications

L&#39;attivazione persistente del inibitori G recettori accoppiati alla proteina provoca sensibilizzazione della segnalazione ciclasi ciclasi. Per identificare le vie molecolari essenziali, sono necessari approcci nonbiased, tuttavia, questa strategia richiede lo sviluppo di una base cellulare scalabile saggio cAMP sensibilizzazione. Qui, descriviamo un test di sensibilizzazione per la piccola molecola e lo screening siRNA.

Farmaco-indotta Sensibilizzazione della ciclasi: L&#39;ottimizzazione del dosaggio e miniaturizzazione per piccole molecole di siRNA e applicazioni di screening

Sensitization of adenylyl cyclase (AC) signaling has been implicated in a variety of neuropsychiatric and neurologic disorders including substance abuse ...

drug-induced-sensitization-adenylyl-cyclase-assay-streamlining

Research

JoVE Journal

Bioengineering

12.6K Views.  Purdue University.  L'attivazione persistente del inibitori G recettori accoppiati alla proteina provoca sensibilizzazione della segnalazione ciclasi ciclasi. Per identificare le vie molecolari essenziali, sono necessari approcci nonbiased, tuttavia, questa strategia richiede lo sviluppo di una base cellulare scalabile saggio cAMP sensibilizzazione. Qui, descriviamo un test di sensibilizzazione per la piccola molecola e lo screening siRNA. 

Video: Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications

Cell-based Calcium Assay for Medium to High Throughput Screening of TRP Channel Functions using FlexStation 3

The Molecular Devices' FlexStation 3 is a benchtop multi-mode microplate reader capable of automated fluorescence measurement in multi-well plates. It is ideal for medium- to high-throughput screens in academic settings. It has an integrated fluid transfer module equipped with a multi-channel pipetter and the machine reads one column at a time to monitor fluorescence changes of a variety of fluorescent reagents. For example, FlexStation 3 has been used to study the function of Ca2+-permeable ion channels and G-protein coupled receptors by measuring the changes of intracellular free Ca2+ levels. Transient receptor potential (TRP) channels are a large family of nonselective cation channels that play important roles in many physiological and pathophysiological functions. Most of the TRP channels are calcium permeable and induce calcium influx upon activation. In this video, we demonstrate the application of FlexStation 3 to study the pharmacological profile of the TRPA1 channel, a molecular sensor for numerous noxious stimuli. HEK293 cells transiently or stably expressing human TRPA1 channels, grown in 96-well plates, are loaded with a Ca2+-sensitive fluorescent dye, Fluo-4, and real-time fluorescence changes in these cells are measured before and during the application of a TRPA1 agonist using the FLEX mode of the FlexStation 3. The effect of a putative TRPA1 antagonist was also examined. Data are transferred from the SoftMax Pro software to construct concentration-response relationships of TRPA1 activators and inhibitors.

This video provides a detailed protocol for studying the pharmacological profile of human TRPA1 channels using FlexStation 3. The protocol covers details of cell preparation, dye loading and operation of the microplate reader, FlexStation 3.

Saggio basato su cellule di calcio per le medie e High Throughput Screening del PRT Funzioni canale utilizzando FlexStation 3

The Molecular Devices' FlexStation 3 is a benchtop multi-mode microplate reader capable of automated fluorescence measurement in multi-well plates.  It is ...

Ricerca

Bioingegneria

Wideband Optical Detector of Ultrasound for Medical Imaging Applications

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic imaging. In medical applications, one of the major limitations of optical sensing technology is its susceptibility to environmental conditions, e.g. changes in pressure and temperature, which may saturate the detection. Additionally, the clinical environment often imposes stringent limits on the size and robustness of the sensor. In this work, the combination of pulse interferometry and fiber-based optical sensing is demonstrated for ultrasound detection. Pulse interferometry enables robust performance of the readout system in the presence of rapid variations in the environmental conditions, whereas the use of all-fiber technology leads to a mechanically flexible sensing element compatible with highly demanding medical applications such as intravascular imaging. In order to achieve a short sensor length, a pi-phase-shifted fiber Bragg grating is used, which acts as a resonator trapping light over an effective length of 350 &#181;m. To enable high bandwidth, the sensor is used for sideway detection of ultrasound, which is highly beneficial in circumferential imaging geometries such as intravascular imaging. An optoacoustic imaging setup is used to determine the response of the sensor for acoustic point sources at different positions.

Optical detection of ultrasound is impractical in many imaging scenarios because it often requires stable environmental conditions. We demonstrate an optical technique for ultrasound sensing in volatile environments with miniaturization and sensitivity levels appropriate for optoacoustic imaging in restrictive scenarios, e.g. intravascular applications.

Wideband rivelatore ottico di ultrasuono per applicazioni Medical Imaging

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic ...

Porous Silicon Microparticles for Delivery of siRNA Therapeutics

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the successful implementation of siRNA therapy requires the use of delivery platforms that can overcome the major challenges of siRNA delivery, such as enzymatic degradation, low intracellular uptake and lysosomal entrapment. Here, a protocol for the preparation and use of a biocompatible and effective siRNA delivery system is presented. This platform consists of polyethylenimine (PEI) and arginine (Arg)-grafted porous silicon microparticles, which can be loaded with siRNA by performing a simple mixing step. The silicon particles are gradually degraded over time, thereby triggering the formation of Arg-PEI/siRNA nanoparticles. This delivery vehicle provides a means for protecting and internalizing siRNA, without causing cytotoxicity. The major steps of polycation functionalization, particle characterization, and siRNA loading are outlined in detail. In addition, the procedures for determining particle uptake, cytotoxicity, and transfection efficacy are also described.

Delivery remains the main challenge for the therapeutic implementation of small interfering RNA (siRNA). This protocol involves the use of a multifunctional and biocompatible siRNA delivery platform, consisting of arginine and polyethylenimine grafted porous silicon microparticles.

Poroso Silicon microparticelle per consegna di siRNA Therapeutics

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the ...

A Rapid and Quantitative Fluorimetric Method for Protein-Targeting Small Molecule Drug Screening

We demonstrate a new drug screening method for determining the binding affinity of small drug molecules to a target protein by forming fluorescent gold nanoclusters (Au NCs) within the drug-loaded protein, based on the differential fluorescence signal emitted by the Au NCs. Albumin proteins such as human serum albumin (HSA) and bovine serum albumin (BSA) are selected as the model proteins. Four small molecular drugs (e.g., ibuprofen, warfarin, phenytoin, and sulfanilamide) of different binding affinities to the albumin proteins are tested. It was found that the formation rate of fluorescent Au NCs inside the drug loaded albumin protein under denaturing conditions (i.e., 60 &#176;C or in the presence of urea) is slower than that formed in the pristine protein (without drugs). Moreover, the fluorescent intensity of the as-formed NCs is found to be inversely correlated to the binding affinities of these drugs to the albumin proteins. Particularly, the higher the drug-protein binding affinity, the slower the rate of Au NCs formation, and thus a lower fluorescence intensity of the resultant Au NCs is observed. The fluorescence intensity of the resultant Au NCs therefore provides a simple measure of the relative binding strength of different drugs tested. This method is also extendable to measure the specific drug-protein binding constant (KD) by simply varying the drug content preloaded in the protein at a fixed protein concentration. The measured results match well with the values obtained using other prestige but more complicated methods.

A protocol for small molecular drug screening based on in-situ synthesis of ultrasmall fluorescent gold nanoclusters (Au NCs) using drug-loaded protein as template is presented. This method is simple to determine the binding affinity of drugs to a target protein by a visible fluorescent signal emitted from the protein-templated Au NCs.

Una rapida e quantitativa metodo fluorimetrico per lo screening di stupefacenti piccole molecole di proteine ​​Targeting

We demonstrate a new drug screening method for determining the binding affinity of small drug molecules to a target protein by forming fluorescent gold ...

Fabrication of Mechanically Tunable and Bioactive Metal Scaffolds for Biomedical Applications

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness and low bioactivity of metals. In this study, we have developed a new method towards fabricating a new type of bioactive and mechanically reliable porous metal scaffolds-densified porous Ti scaffolds. The method consists of two fabrication processes, 1) the fabrication of porous Ti scaffolds by dynamic freeze casting, and 2) coating and densification of the porous scaffolds. The dynamic freeze casting method to fabricate porous Ti scaffolds allowed the densification of porous scaffolds by minimizing the chemical contamination and structural defects. The densification process is distinctive for three reasons. First, the densification process is simple, because it requires a control of only one parameter (degree of densification). Second, it is effective, as it achieves mechanical enhancement and sustainable release of biomolecules from porous scaffolds. Third, it has broad applications, as it is also applicable to the fabrication of functionally graded porous scaffolds by spatially varied strain during densification.

Bioactive and mechanically reliable metal scaffolds have been fabricated through a method which consists of two processes, dynamic freeze casting for the fabrication of porous Ti, and coating and densification of the Ti scaffolds. The densification process is simple, effective and applicable to the fabrication of functionally graded scaffolds.

Fabbricazione di meccanicamente Tunable e Bioactive metallo Ponteggi per applicazioni biomediche

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness ...

Light-mediated Formation and Patterning of Hydrogels for Cell Culture Applications

Click chemistries have been investigated for use in numerous biomaterials applications, including drug delivery, tissue engineering, and cell culture. In particular, light-mediated click reactions, such as photoinitiated thiol&#8722;ene and thiol&#8722;yne reactions, afford spatiotemporal control over material properties and allow the design of systems with a high degree of user-directed property control. Fabrication and modification of hydrogel-based biomaterials using the precision afforded by light and the versatility offered by these thiol&#8722;X photoclick chemistries are of growing interest, particularly for the culture of cells within well-defined, biomimetic microenvironments. Here, we describe methods for the photoencapsulation of cells and subsequent photopatterning of biochemical cues within hydrogel matrices using versatile and modular building blocks polymerized by a thiol&#8722;ene photoclick reaction. Specifically, an approach is presented for constructing hydrogels from allyloxycarbonyl (Alloc)-functionalized peptide crosslinks and pendant peptide moieties and thiol-functionalized poly(ethylene glycol) (PEG) that rapidly polymerize in the presence of lithium acylphosphinate photoinitiator and cytocompatible doses of long wavelength ultraviolet (UV) light. Facile techniques to visualize photopatterning and quantify the concentration of peptides added are described. Additionally, methods are established for encapsulating cells, specifically human mesenchymal stem cells, and determining their viability and activity. While the formation and initial patterning of thiol-alloc hydrogels are shown here, these techniques broadly may be applied to a number of other light and radical-initiated material systems (e.g., thiol-norbornene, thiol-acrylate) to generate patterned substrates.

We describe a sequential process for light-mediated formation and subsequent biochemical patterning of synthetic hydrogel matrices for three-dimensional cell culture applications. The construction and modification of hydrogels with cytocompatible photoclick chemistry is demonstrated. Additionally, facile techniques to quantify and observe patterns and determine cell viability within these hydrogels are presented.

Formazione Light-mediata ed il modello di idrogel per colture cellulari

Click chemistries have been investigated for use in numerous biomaterials applications, including drug delivery, tissue engineering, and cell culture. In ...

Extraction of Plant-based Capsules for Microencapsulation Applications

Microcapsules derived from plant-based spores or pollen provide a robust platform for a diverse range of microencapsulation applications. Sporopollenin exine capsules (SECs) are obtained when spores or pollen are processed so as to remove the internal sporoplasmic contents. The resulting hollow microcapsules exhibit a high degree of micromeritic uniformity and retain intricate microstructural features related to the particular plant species. Herein, we demonstrate a streamlined process for the production of SECs from Lycopodium clavatum spores and for the loading of hydrophilic compounds into these SECs. The current SEC isolation procedure has been recently optimized to significantly reduce the processing requirements which are conventionally used in SEC isolation, and to ensure the production of intact microcapsules. Natural L. clavatum spores are defatted with acetone, treated with phosphoric acid, and extensively washed to remove sporoplasmic contents. After acetone defatting, a single processing step using 85% phosphoric acid has been shown to remove all sporoplasmic contents. By limiting the acid processing time to 30 hr, it is possible to isolate clean SECs and avoid SEC fracturing, which has been shown to occur with prolonged processing time. Extensive washing with water, dilute acids, dilute bases, and solvents ensures that all sporoplasmic material and chemical residues are adequately removed. The vacuum loading technique is utilized to load a model protein (Bovine Serum Albumin) as a representative hydrophilic compound. Vacuum loading provides a simple technique to load various compounds without the need for harsh solvents or undesirable chemicals which are often required in other microencapsulation protocols. Based on these isolation and loading protocols, SECs provide a promising material for use in a diverse range of microencapsulation applications, such as, therapeutics, foods, cosmetics, and personal care products.

This protocol/manuscript describes a streamlined process for the production of sporopollenin exine capsules (SECs) from Lycopodium clavatum spores and for the loading of hydrophilic compounds into these SECs.

Capsule Estrazione di Plant-based per applicazioni di microincapsulazione

Microcapsules derived from plant-based spores or pollen provide a robust platform for a diverse range of microencapsulation applications. Sporopollenin ...

Applications for Open Source Microplate-Compatible Illumination Panels

Microplates are commonly used in the modern laboratory environment for a wide variety of tasks both in small-scale laboratory benchtop operations as well as large-scale high-throughput screening (HTS) campaigns. Though laboratory automation has greatly increased the utility of microplates there remain instances where automation-based instrumentation is not feasible, cost-effective or compatible with microplate formatting needs. In these cases, microplates must be manually prepared. Problematic to manual microplate manipulations is that a number of difficulties can arise pertaining to the accurate tracking of sample operations, data record keeping and quality control (QC) inspection for well artifacts or formatting errors. As microplate well densities increase (i.e., 96-well, 384-well, 1536-well) the potential for introducing errors also drastically increases.&#160; Moreover, for small bench-top laboratory operations there exists a need to improve the ease and accuracy of sample handling in a cost-effective fashion. Herein, we describe a system that acts as a semi-automated pipetting guide referred to as the Microplate Assistive Pipetting Light Emitter (M.A.P.L.E.). &#160;M.A.P.L.E. has multiple uses for supporting compound hit-picking and microplate preparation for assay development in high-throughput screening or laboratory benchtop operations, as well as QC/quality assurance (QA) diagnostic evaluation of microplate quality or visualizing well formatting errors.

Microplate Assistive Pipetting Light Emitter (M.A.P.L.E.) is a computer-driven device that systematically illuminates microtiter wells to provide guidance for the manual preparation of microplates.&#160; M.A.P.L.E. improves the accuracy of microplate preparation while automating data recordkeeping. &#160;In addition, it can assist with examining microplate quality or aid in the detection of errors.&#160; &#160;

Applicazioni per pannelli di illuminazione compatibili con microplacca open source

Microplates are commonly used in the modern laboratory environment for a wide variety of tasks both in small-scale laboratory benchtop operations as well ...

Screening and Identification of Small Peptides Targeting Fibroblast Growth Factor Receptor2 using a Phage Display Peptide Library

The human Fibroblast Growth Factor Receptor (FGFR) family comprises four members, namely, FGFR1, FGFR2, FGFR3, and FGFR4, that are involved in various biological activities including cell proliferation, survival, migration and differentiation. Several aberrations in the FGFR signaling pathway, owing to mutations or gene amplification events, have been identified in various types of cancers. Hence, recent research has focused on developing strategies involving therapeutic targeting of FGFRs. Current FGFR inhibitors at various stages of pre-clinical and clinical development include either small molecule inhibitors of tyrosine kinases or monoclonal antibodies, with only a few peptide- based inhibitors in the pipeline. Here, we provide a protocol using phage display technology to screen small peptides as antagonists of FGFR2. Briefly, a library of phage-displayed peptides was incubated in a plate coated with FGFR2. Subsequently, unbound phage was washed off by TBST (TBS + 0.1% [v/v] Tween-20), and bound phage was eluted with 0.2 M glycine-HCl buffer (pH 2.2). The eluted phage was further amplified and used as input for the next round of biopanning. Following three rounds of biopanning, the peptide sequences of individual phage clones were identified by DNA sequencing. Finally, the screened peptides were synthesized and analyzed for affinity and biological activity.

Herein, we present a detailed protocol for screening small peptides that bind to FGFR2 using a phage display peptide library. We further analyze the affinity of the selected peptides toward FGFR2 in vitro and its ability to suppress cell proliferation.

Screening e identificazione di piccoli peptidi mirati Fibroblast Growth Factor Receptor2 utilizzando una Phage Display Peptide Library

The human Fibroblast Growth Factor Receptor (FGFR) family comprises four members, namely, FGFR1, FGFR2, FGFR3, and FGFR4, that are involved in various ...

Rapid Fabrication of Custom Microfluidic Devices for Research and Educational Applications

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to submillimeter scales. A rapid increase in the use of this technology in the biological sciences has prompted a need for methods that are accessible to a wide range of research groups. Current fabrication standards, such as PDMS bonding, require expensive and time consuming lithographic and bonding techniques. A viable alternative is the use of equipment and materials that are easily affordable, require minimal expertise and allow for the rapid iteration of designs. In this work we describe a protocol for designing and producing PET-laminates (PETLs), microfluidic devices that are inexpensive, easy to fabricate, and consume significantly less time to generate than other approaches to microfluidics technology. They consist of thermally bonded film sheets, in which channels and other features are defined using a craft cutter. PETLs solve field-specific technical challenges while dramatically reducing obstacles to adoption. This approach facilitates the accessibility of microfluidics devices in both research and educational settings, providing a reliable platform for new methods of inquiry.

Here we present a protocol to design and fabricate custom microfluidic devices with minimal financial and time investment. The aim is to facilitate the adoption of microfluidic technologies in biomedical research laboratories and educational settings.