CRM is a Damon Runyon-Genentech Clinical Investigator. This work was supported, in part, by grants to CRM from the Damon Runyon Cancer Research Foundation (CI-45-09), Department of Defense (W81XWH-09-2-0042), and University of North Carolina University Cancer Research Fund (UCRF). The authors wish to thank Daniel Roth for mouse husbandry assistance. The authors also wish to thank Hannah Chae, Carter McCormick, Demi Canoutas, Stephanie Gillette, and Susannah Krom for tissue culture and immunofluorescence assistance.

The authors have nothing to disclose.

I passaggi più critici per assicurare la corretta raccolta e la cultura di astrociti corticali sono 1) di asportare la corteccia senza prendere il tessuto al di sotto del corpo calloso, 2) per togliere le meningi, 3) per dissociare completamente le cellule, e 4) per arricchire di GFAP + astrociti. Anche se abbiamo usato meccanica (scuotimento) e genetico (limitazione di ricombinazione genetica con un vettore Ad5GFAPCre o l&#39;utilizzo di una trasformazione transgene dominante (TgGZT 121)...

Astrocitomi sono il tumore cerebrale primario più comune e glioblastoma (GBM), un astrocitoma di grado IV, è il sottotipo più comune e aggressivo, con una sopravvivenza mediana di 12-15 mesi 1,2. Invasione di astrocitomi diffusi, in particolare GBM, preclude la resezione chirurgica completa, limita l&#39;efficacia delle terapie adiuvanti, e porta inevitabilmente alla post-trattamento recidiva 3. I pazienti inizialmente presenti sia con de novo (primario) GBM o con astrocitoma di grado inferiore che progredisce inevitabilmente (secondaria) GBM 4. GBM è genomicamente eterogeneo e caratterizzato da mutazioni si escludono a vicenda e co-si verificano in geni che governano tre principali vie di segnalazione: G 1 / S (Rb) checkpoint del ciclo cellulare, il recettore tirosin chinasi (RTK), e TP53 Percorsi di 5-7. GBM è composto da quattro sottotipi genomiche con profili di espressione distinti che assomigliano a diversi tipi di cellule del cervello, suggerendo che GBM sottotipo è influenfluenzati dalla sua cella di origine 6,8,9. Modelli di astrocitoma migliori sono tenuti a definire il ruolo di specifiche combinazioni di mutazioni in particolari tipi di cellule durante astrocitoma patogenesi. Sfruttando questi modelli per lo sviluppo di farmaci più efficaci preclinico in ultima analisi, contribuire a migliorare i risultati dei pazienti. Modelli di astrocitoma correnti comprendono stabilite linee cellulari umane, paziente derivante xenotrapianti (PDX), normali astrociti umani geneticamente modificati e cellule staminali neurali (NSC), e topi geneticamente ingegnerizzati (GEM) 10-14. Abbiamo sviluppato una alternativa, GEM non germinali (NGEM) modello 15 che utilizza cellule cerebrali primari - astrociti corticali e NSC - raccolti da GEM ospitare diverse combinazioni di alleli floxed oncogeni. L&#39;obiettivo era quello di generare modelli di astrocitoma con cellule geneticamente definite che potrebbero essere caratterizzati fenotipicamente sia in vitro che in vivo e potenzialmente utilizzabili per lo sviluppo di farmaci in preclinico itopi mmune-competenti. Linee cellulari umane Fondata sono il modello più comunemente usato di astrocitoma patogenesi e la risposta ai farmaci in vitro e in vivo. Essi sono tecnicamente semplice, ampiamente disponibile, e hanno definito cinetica e cancerogenicità su ortotopico xenotrapianto in topi immunodeficienti 10,11,16-18 . I loro svantaggi includono l&#39;incapacità di generare linee cellulari stabilizzate da astrocitomi di basso grado, limitando studio solo per astrocitoma di alta qualità; mancanza di una cella definita di origine; la presenza di anomalie genomiche complesse, spesso con profili genomici che si differenziano notevolmente dal campione del paziente originale; e suscettibilità fenotipica e genotipica deriva durante la cultura di serie nel siero 11,17,19-22. Le conseguenze fenotipiche delle singole mutazioni oncogene in linee cellulari GBM umani stabiliti possono essere mascherati dalla moltitudine di anomalie che sono effettivamente presenti, che spesso preclude elucidation delle conseguenze dirette genotipo-fenotipo. PDX sono generati attraverso il passaggio sottocutanea di cellule di astrocitoma-isolati di pazienti in topi immunodeficienti o attraverso la loro cultura come sferoidi non aderenti a definito, terreno privo di siero prima dell&#39;iniezione ortotopico nel cervello di topi immunodeficienti 12,23. PDX mantenere più accuratamente il paesaggio genomico di astrocitoma umano, ma simile a linee cellulari umane stabilite, l&#39;effetto fenotipico di singole mutazioni oncogene può essere mascherato a causa della loro complessità genomica 19,24. Per definire le conseguenze fenotipiche di specifiche mutazioni oncogene, in particolare in risposta alle nuove terapie, i pannelli di linee cellulari umane stabiliti o PDX sono spesso utilizzati per stabilire correlazioni genotipo-fenotipo, mostrare generalizzabilità, e ridurre al minimo la probabilità di effetti specifiche della linea di cellule. Mentre PDX ricapitolare con precisione le caratteristiche istopatologiche di astrocitoma umano, incLuding invasione, xenotrapianti ortotopici di linee cellulari umane stabiliti in genere non 21,23,25. Inoltre, normali astrociti umani e NSC sono stati geneticamente ingegnerizzato con mutazioni oncogene definite per modellare astrocitoma tumorigenesi in vitro e in vivo 13,14,26. Queste cellule non hanno la complessità genomica delle linee cellulari umane consolidate e PDX e ricapitolano accuratamente istopatologia astrocitoma umano, ma richiedono xenotrapianto nei roditori immunodeficienti in vivo. Poiché tutti i modelli cellulari umani richiedono host roditori immunodeficienti per evitare immuno-mediata rifiuto xenotrapianto, questi modelli non riescono a ricapitolare le interazioni tumore-stroma nativi di un sistema singeniche e mancano di un sistema immunitario intatto, limitando indagine preclinica di stroma-mirata e immuno-modulazione terapie 10,11. GEM permesso di esame delle conseguenze fenotipiche di combinazioni predeterminate di muta oncogenozioni in vivo durante la tumorigenesi in situ. Considerando che la GEM non-condizionale hanno mutazioni all&#39;interno di tutti i tessuti durante lo sviluppo, GEM condizionale hanno floxed alleli oncogeni che consentono il targeting di mutazioni limitando ricombinazione Cre-mediata di specifici tipi cellulari attraverso l&#39;uso di specifici del tipo di cellule promotori 10,11,15,18. Condizionale astrocitoma GEM sono stati utilizzati per chiarire i ruoli funzionali di mutazioni in oncogeni tipi cellulari distinti all&#39;interno di un cervello intatto 11. L&#39;utilità di preclinico in situ gliomagenesis usando GEM condizionale è limitato da una serie di fattori, tra cui 1) la mancanza di una correlazione in vitro, 2) la difficoltà nel generare grandi coorti di topi con genotipi complessi, 3) tempi di latenza delle nello sviluppo del tumore in situ , 4) e stocastico progressione tumorale. Perché in situ tumorigenesi manca un modello corrispondente in vitro, test anti-droga in vitro non può essere eseguita wesima modelli GEM condizionali convenzionali. A differenza di altri tipi di tumore, modelli GEM condizionali di astrocitoma sono raramente indotti da singole mutazioni oncogeniche 11. Pertanto, i regimi di allevamento complessi sono necessari per generare GEM condizionale con più mutazioni oncogene. Inoltre, astrocitoma iniziazione si verifica con penetranza variabile, dopo un lungo periodo di latenza in questi modelli, mentre la progressione di astrocitomi di alto grado si verifica in genere in modo non uniforme, stocastico modo e dà infine origine a tumori con complessi paesaggi genomiche e cinetica di crescita rapida 27, 28. La penetranza variabile e la natura stocastica della progressione maligna nei modelli GEM condizionale richiede che i singoli topi proiettati da radiografie per rilevare la presenza e la posizione di astrocitomi di alto grado prima del loro arruolamento negli studi preclinici di droga. Nel loro insieme, queste limitazioni ostacolano la generazione e la sperimentazione di grandi coorti di GEM condizionale necessario per prtest eClinical droga. Il sistema GEM RCAS-TVA, che utilizza retrovirali aviaria (RCA) vettori per infettare GEM ingegnerizzato per esprimere il recettore virale (TVA) su specifici tipi di cellule neurali, è stato ampiamente utilizzato per modellare astrocitoma tumorigenesi 11. In contrasto con GEM condizionale, questo sistema modello permette l&#39;introduzione di mutazioni multiple oncogeni in tipi specifici di cellule, senza la necessità di sistemi di allevamento complessi. Tuttavia, è limitato da penetranza variabile, il requisito per dividere attivamente le cellule per ottenere l&#39;integrazione virale, e l&#39;inserimento casuale di transgeni nel genoma dell&#39;ospite 29. GEM (NGEM) Modelli non germinali, che utilizzano le cellule raccolte da GEM, stanno diventando sempre più importanti perché superare molte delle limitazioni degli altri sistemi modello 15. Il ruolo di avvio tipo di cellula e mutazioni co-occorrenti in astrocitoma patogenesi sono difficili da scoraggiareminiera utilizzando stabilito linee cellulari umane GBM o PDX perché derivano da tumori allo stadio terminale che hanno accumulato ampi mutazioni genetiche in tipi cellulari non definiti nel corso della progressione maligna. Al contrario, tutti i tipi di astrocitoma possono essere modellati utilizzando NGEM inducendo definite mutazioni genetiche all&#39;interno di specifici tipi di cellule cerebrali purificate 11,30. Così, l&#39;influenza di mutazioni genetiche specifiche e tipo cellulare su fenotipi cellulari e molecolari può essere determinata in vitro e in vivo. Simile a linee di cellule GBM umani stabiliti, in vitro test iniziale in droga utilizzando NGEM può essere utilizzato per dare priorità farmaci per la sperimentazione in vivo che utilizzano le stesse cellule. Tumorigenesi in vivo può essere determinato da allotrapianto di cellule NGEM ortotopicamente nel cervello dei fratellini singeniche immuno-competente 30. Questi modelli trapianto allogenico ortotopici permettono quindi nei test in vivo non solo convenzionali citotossici unnd terapie mirate, ma immuno-modulante e terapie stroma mirate pure. Infine, il ruolo del microambiente sulla iniziazione tumorale e la progressione può essere determinata confrontando i risultati tra NGEM e modelli GEM convenzionali utilizzando le stesse mutazioni negli stessi tipi cellulari. Noi e altri abbiamo sviluppato astrocitoma NGEM utilizzando cellule primarie - astrociti, NSC, o cellule precursori degli oligodendrociti (OPC) - raccolte da GEM 30-34. La logica alla base dello sviluppo di un astrocitoma NGEM era quello di creare un modello per determinare le conseguenze fenotipiche delle mutazioni in oncogeni specifici tipi cellulari che potrebbero essere utilizzati per la sperimentazione preclinica dei farmaci in vitro e in vivo in animali immuno-competenti. Abbiamo raccolto astrociti fenotipicamente WT corticali e NSC da non esprimono Cre, GEM subordinata mantenuto su un 94% C57 / BL6 sfondo&gt; con floxed RB percorso - Rb1 loxP / loxP, o TgGZT121 - e floxed RTK / RAS / PI3K pathway - Nf1 loxP / loxP, Kras G12D, Pten loxP / loxP - geni in varie combinazioni 35-39. Siamo indotti ricombinazione genetica in vitro utilizzando vettori adenovirali codificanti Cre ricombinasi. Perché raccolti astrociti corticali contengono una miscela di tipi di cellule, abbiamo utilizzato vettori Ad5GFAPCre o transgeni oncogeni dominanti, come TgGZT 121 guidato dal promotore GFAP umana, per arricchire di GFAP + astrociti corticali in queste culture. Abbiamo definito le conseguenze fenotipiche della G 1 / S (Rb), MAPK, e mutazioni di PI3K pathway in astrociti corticali e NSC in vitro e in vivo. MAPK e PI3K pathway attivato G1 / S-difettosi astrociti molecolarmente imitato GBM umano proneurale e, a seguito di iniezione ortotopico, tumori formate in una posizione pre-definita con cinetica di crescita uniformi, brevi latenze, e la istopatologiciAL caratteristiche di GBM umano 30. Monitoraggio longitudinale della crescita tumorale in vivo aiuta droga test preclinici attraverso la normalizzazione delle coorti di trattamento e analisi quantitativa della crescita tumorale in risposta al trattamento 40. Abbiamo determinato cinetica di crescita tumorale da parte longitudinale bioluminescenza imaging topi iniettati con luciferasi che esprimono astrociti corticali. Pertanto, astrociti corticali e NSC derivate da GEM condizionale forniscono un sistema modello trattabili per la definizione delle conseguenze funzionali di mutazioni astrocitoma associate e di un sistema di potenziale modello per lo sviluppo di farmaci preclinico.

<table border="0" cellpadding="0" cellspacing="0" width="784">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:241px;">Name of Material/ Equipment</td>
			<td style="width:191px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:233px;">Comments/Description</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:241px;">Dulbecco&#39;s Modified Eagle Medium (DMEM) (1X)</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">11995065</td>
			<td style="width:233px;">DMEM can also be purchased from other suppliers including GIBCOSigma and Cellgro</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Fetal Bovine Serum, Regular</td>
			<td style="width:191px;">Cellgro</td>
			<td style="width:119px;">35-010-CV</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Penicillin-Streptomycin</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">15140122</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Sharp-Pointed Dissecting Scissors</td>
			<td style="width:191px;">Fisher Scientific</td>
			<td style="width:119px;">08-395</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Cartilage Thumb Forceps, Curved</td>
			<td style="width:191px;">Fisher Scientific</td>
			<td style="width:119px;">1631</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Miltex 17-301 Style 1 Jeweler Style Forceps, Fine, 4</td>
			<td style="width:191px;">Miltex</td>
			<td style="width:119px;">17-301</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Ethanol (200 proof)</td>
			<td style="width:191px;">Decon Labs</td>
			<td style="width:119px;">2710</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Razor Blades</td>
			<td style="width:191px;">VWR</td>
			<td style="width:119px;">55411-050</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Hanks&#39; Balanced Salt Solution (HBSS) (1X), liquid</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">14175-095</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:241px;">TrypLE Express (1X), Phenol Red</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">12605-010</td>
			<td style="width:233px;">Other Trypsin solutions are also suitable for cortical astrocyte havest and culture</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">CULTURE DISH, 60 x 15 mm</td>
			<td style="width:191px;">Thomas Scientific</td>
			<td style="width:119px;">9380H77</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">15 ml tubes</td>
			<td style="width:191px;">BD Biosciences</td>
			<td style="width:119px;">352096</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">50 ml tubes</td>
			<td style="width:191px;">BD Biosciences</td>
			<td style="width:119px;">352070</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:241px;">Adenovirus stock</td>
			<td style="width:191px;">Gene Transfer Vector Core, U. Iowa</td>
			<td style="width:119px;">Ad5CMVCre</td>
			<td style="width:233px;">Store in 5 &#181;l aliquots at -80 C. Hazardous.&#160; Use Bsl2 safetyy&#160; precautions</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:241px;">Sodium sulfate (Na2SO4)&#160;</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">238597</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:241px;">Potassium sulfate (K2SO4)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">221325</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:241px;">Magnesium chloride (MgCl2)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">M8266</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:241px;">Calcium chloride (CaCl2)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">746495</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">HEPES potassium salt</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">H0527</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">D-(+)- Glucose</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">G8270&#160;</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Phenol Red</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">P3532</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Sodium hydroxide (NaOH)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">S5881</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Papain</td>
			<td style="width:191px;">Worthington</td>
			<td style="width:119px;">LS003127</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">L-Cysteine-HCl</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">C1276</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Syringe filter (0.22 &#181;m pore size)</td>
			<td style="width:191px;">Millipore</td>
			<td style="width:119px;">SLGP033NS</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="80">
			<td height="80" style="height:80px;width:241px;">Neurocult proliferation kit, mouse</td>
			<td style="width:191px;">Stemcell Technologies</td>
			<td style="width:119px;">5702</td>
			<td style="width:233px;">This kit contains the NeuroCult NSC Basal Medium and NeuroCult NSC supplement needed for NSC culture</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">0.2% Heparin solution</td>
			<td style="width:191px;">Stemcell Technologies</td>
			<td style="width:119px;">7980</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">EGF&#160;</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">PMG8041</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">bFGF&#160;</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">PHG0261</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Hanks&#39; Balanced Salt Solution (HBSS) (10X)</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">14185-052</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:241px;">Magnesium sulfate (MgSO4)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">M7506</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:241px;">Sodium bicarbonate (NaHCO3)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">S5761</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">E-64</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">E3132</td>
			<td style="width:233px;">Make 10 mM stock in DMSO, store at -20 &#176;C</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">6-well plates</td>
			<td style="width:191px;">Fisher Scientific</td>
			<td style="width:119px;">07-200-83</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Cell strainer (40 &#181;m pore size)</td>
			<td style="width:191px;">Corning</td>
			<td style="width:119px;">352340</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Stem cell dissociation solution</td>
			<td style="width:191px;">Stemcell Technologies</td>
			<td style="width:119px;">5707</td>
			<td style="width:233px;">Alternatively, use gentle enzyme solutions such as Accutase</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:241px;">Methyl cellulose 15 cP</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:119px;">M7027</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">Dulbecco&#39;s Modified Eagle&#39;s Media 2X</td>
			<td style="width:191px;">Millipore</td>
			<td style="width:119px;">SLM-202-B</td>
			<td style="width:233px;">For making 5% methyl cellulose solution</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:241px;">1.7mL Snap Cap Microcentrifuge Tube</td>
			<td style="width:191px;">Corning</td>
			<td align="right" style="width:119px;">3620</td>
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			<td height="40" style="height:40px;width:241px;">Hamilton syringe, 250 &#181;l LT no needle</td>
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			<td height="20" style="height:20px;width:241px;">Disposable 18 ga needles&#160;</td>
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			<td height="20" style="height:20px;width:241px;">27 ga 1/2&#34; luer tip needle</td>
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			<td height="20" style="height:20px;width:241px;">2,2,2-Tribromoethanol (Avertin)</td>
			<td style="width:191px;">Sigma-Aldrich</td>
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			<td height="20" style="height:20px;width:241px;">Betadine</td>
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			<td height="20" style="height:20px;width:241px;">Lidocaine&#160;</td>
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			<td height="60" style="height:60px;width:241px;">CellTiter 96 AQueous One Solution Cell Proliferation Assay (MTS)</td>
			<td style="width:191px;">Promega</td>
			<td style="width:119px;">G3580</td>
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			<td height="20" style="height:20px;width:241px;">Anti-Sox2</td>
			<td style="width:191px;">Millipore</td>
			<td style="width:119px;">AB5603</td>
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			<td height="40" style="height:40px;width:241px;">Polyclonal Rabbit Anti-Glial Fibrillary Acidic Protein (GFAP)</td>
			<td style="width:191px;">Dako</td>
			<td style="width:119px;">Z0334&#160;</td>
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			<td height="20" style="height:20px;width:241px;">IVIS Kinetic</td>
			<td style="width:191px;">PerkinElmer</td>
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			<td style="width:233px;">For in vivo imaging</td>
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			<td height="40" style="height:40px;width:241px;">D-Luciferin - K+ Salt Bioluminescent Substrate</td>
			<td style="width:191px;">PerkinElmer</td>
			<td style="width:119px;">122796</td>
			<td style="width:233px;">For in vivo bioluminescence imaging</td>
		</tr>
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			<td height="20" style="height:20px;width:241px;">EdU Imaging Kit</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:119px;">C10340</td>
			<td style="width:233px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:241px;">MSCV Luciferase PGK-hygro</td>
			<td style="width:191px;">Addgene</td>
			<td style="width:119px;">18782</td>
			<td></td>
		</tr>
	</tbody>
</table>

modeling astrocytoma pathogenesis in vitro and in vivo using cortical astrocytes or neural stem cells from conditional, genetically engineered mice

Current astrocytoma models are limited in their ability to define the roles of oncogenic mutations in specific brain cell types during disease pathogenesis and their utility for preclinical drug development. In order to design a better model system for these applications, phenotypically wild-type cortical astrocytes and neural stem cells (NSC) from conditional, genetically engineered mice (GEM) that harbor various combinations of floxed oncogenic alleles were harvested and grown in culture. Genetic recombination was induced in vitro using adenoviral Cre-mediated recombination, resulting in expression of mutated oncogenes and deletion of tumor suppressor genes. The phenotypic consequences of these mutations were defined by measuring proliferation, transformation, and drug response in vitro. Orthotopic allograft models, whereby transformed cells are stereotactically injected into the brains of immune-competent, syngeneic littermates, were developed to define the role of oncogenic mutations and cell type on tumorigenesis in vivo. Unlike most established human glioblastoma cell line xenografts, injection of transformed GEM-derived cortical astrocytes into the brains of immune-competent littermates produced astrocytomas, including the most aggressive subtype, glioblastoma, that recapitulated the histopathological hallmarks of human astrocytomas, including diffuse invasion of normal brain parenchyma. Bioluminescence imaging of orthotopic allografts from transformed astrocytes engineered to express luciferase was utilized to monitor in vivo tumor growth over time. Thus, astrocytoma models using astrocytes and NSC harvested from GEM with conditional oncogenic alleles provide an integrated system to study the genetics and cell biology of astrocytoma pathogenesis in vitro and in vivo and may be useful in preclinical drug development for these devastating diseases.

Abbiamo sviluppato un sistema modello NGEM con astrociti corticali e NSC raccolte da neonatale GEM l&#39;ospitare floxed condizionali alleli oncogeni che possono essere caratterizzati fenotipicamente in vitro e in vivo (Figura 1). Al fine di indagare le conseguenze delle mutazioni oncogeniche specificamente in astrociti corticali in vitro, è fondamentale per arricchire la prima per astrociti. Raccolti astrociti corticali contengono una miscela di microglia, astrociti, oligode...

Watch this Scientific Journal Video about Modeling Astrocytoma Pathogenesis In Vitro and In Vivo Using Cortical Astrocytes or Neural Stem Cells from Conditional, Genetically Engineered Mice at JoVE.co

Modeling Astrocytoma Pathogenesis In Vitro and In Vivo Using Cortical Astrocytes or Neural Stem Cells from Conditional, Genetically Engineered Mice

Phenotypically wild-type astrocytes and neural stem cells harvested from mice engineered with floxed, conditional oncogenic alleles and transformed via viral Cre-mediated recombination can be used to model astrocytoma pathogenesis in vitro and in vivo by orthotopic injection of transformed cells into brains of syngeneic, immune-competent littermates.

Modellazione Astrocitoma Patogenesi<em&gt; In Vitro</em&gt; E<em&gt; In Vivo</em&gt; Utilizzo corticale astrociti o cellule staminali neurali da condizionale, topi geneticamente ingegnerizzati

Current astrocytoma models are limited in their ability to define the roles of oncogenic mutations in specific brain cell types during disease ...

modeling-astrocytoma-pathogenesis-vitro-vivo-using-cortical

Research

JoVE Journal

Neuroscience

Modeling Astrocytoma Pathogenesis In Vitro and In Vivo Using Cortical Astrocytes or Neural Stem Cells from Conditional, Genetically Engineered Mice

13.3K Views.  University of North Carolina School of Medicine. Phenotypically wild-type astrocytes and neural stem cells harvested from mice engineered with floxed, conditional oncogenic alleles and transformed via viral Cre-mediated recombination can be used to model astrocytoma pathogenesis in vitro and in vivo by orthotopic injection of transformed cells into brains of syngeneic, immune-competent littermates.

Video: Modeling Astrocytoma Pathogenesis In Vitro and In Vivo Using Cortical Astrocytes or Neural Stem Cells from Conditional, Genetically Engineered Mice

Generation of Neural Stem Cells from Discarded Human Fetal Cortical Tissue

Neural stem cells (NSCs) reside along the ventricular zone neuroepithelium during the development of the cortical plate. These early progenitors ultimately give rise to intermediate progenitors and later, the various neuronal and glial cell subtypes that form the cerebral cortex. The capacity to generate and expand human NSCs (so called neurospheres) from discarded normal fetal tissue provides a means with which to directly study the functional aspects of normal human NSC development 1-5. This approach can also be directed toward the generation of NSCs from known neurological disorders, thereby affording the opportunity to identify disease processes that alter progenitor proliferation, migration and differentiation 6-9. We have focused on identifying pathological mechanisms in human Down syndrome NSCs that might contribute to the accelerated Alzheimer's disease phenotype 10,11. Neither in vivo nor in vitro mouse models can replicate the identical repertoire of genes located on human chromosome 21. 
Here we use a simple and reliable method to isolate Down syndrome NSCs from aborted human fetal cortices and grow them in culture. The methodology provides specific aspects of harvesting the tissue, dissection with limited anatomical landmarks, cell sorting, plating and passaging of human NSCs. We also provide some basic protocols for inducing differentiation of human NSCs into more selective cell subtypes.

A simple and reliable method on isolation and culture of neural stem cells from discarded human fetal cortical tissue is described. Cultures derived from known human neurological disorders can be used for characterization of pathological cellular and molecular processes, as well as provide a platform to assess pharmacological efficacy.

Generazione di cellule staminali neurali da scartate tessuto fetale umano corticale

Neural stem cells (NSCs) reside along the ventricular zone neuroepithelium during the development of the cortical plate. These early progenitors ...

Ricerca

Neuroscienze

Modeling Neural Immune Signaling of Episodic and Chronic Migraine Using Spreading Depression In Vitro

Migraine and its transformation to chronic migraine are healthcare burdens in need of improved treatment options. We seek to define how neural immune signaling modulates the susceptibility to migraine, modeled in vitro using spreading depression (SD), as a means to develop novel therapeutic targets for episodic and chronic migraine. SD is the likely cause of migraine aura and migraine pain. It is a paroxysmal loss of neuronal function triggered by initially increased neuronal activity, which slowly propagates within susceptible brain regions. Normal brain function is exquisitely sensitive to, and relies on, coincident low-level immune signaling. Thus, neural immune signaling likely affects electrical activity of SD, and therefore migraine. Pain perception studies of SD in whole animals are fraught with difficulties, but whole animals are well suited to examine systems biology aspects of migraine since SD activates trigeminal nociceptive pathways. However, whole animal studies alone cannot be used to decipher the cellular and neural circuit mechanisms of SD. Instead, in vitro preparations where environmental conditions can be controlled are necessary. Here, it is important to recognize limitations of acute slices and distinct advantages of hippocampal slice cultures. Acute brain slices cannot reveal subtle changes in immune signaling since preparing the slices alone triggers: pro-inflammatory changes that last days, epileptiform behavior due to high levels of oxygen tension needed to vitalize the slices, and irreversible cell injury at anoxic slice centers. 
In contrast, we examine immune signaling in mature hippocampal slice cultures since the cultures closely parallel their in vivo counterpart with mature trisynaptic function; show quiescent astrocytes, microglia, and cytokine levels; and SD is easily induced in an unanesthetized preparation. Furthermore, the slices are long-lived and SD can be induced on consecutive days without injury, making this preparation the sole means to-date capable of modeling the neuroimmune consequences of chronic SD, and thus perhaps chronic migraine. We use electrophysiological techniques and non-invasive imaging to measure neuronal cell and circuit functions coincident with SD. Neural immune gene expression variables are measured with qPCR screening, qPCR arrays, and, importantly, use of cDNA preamplification for detection of ultra-low level targets such as interferon-gamma using whole, regional, or specific cell enhanced (via laser dissection microscopy) sampling. Cytokine cascade signaling is further assessed with multiplexed phosphoprotein related targets with gene expression and phosphoprotein changes confirmed via cell-specific immunostaining. Pharmacological and siRNA strategies are used to mimic and modulate SD immune signaling.

Modeling Neural Immune Signaling of Episodic and Chronic Migraine Using Spreading Depression In Vitro

Migraine and its transformation to chronic migraine are immense healthcare burdens in need of improved treatment options. We seek to define how neural immune signaling modulates the susceptibility to migraine, modeled in vitro using spreading depression in hippocampal slice cultures, as a means to develop novel therapeutic targets.

Modellistica neurale segnalazione immunitario di emicrania episodica e cronica utilizzo Depressione Diffusione In Vitro</em

Migraine and its transformation to chronic migraine are healthcare burdens in need of improved treatment options.  We seek to define how neural immune ...

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

Neuroimaging funzionale con l&#39;impiego dell&#39;ecografia emato-encefalica e la barriera di Turbativa del Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Expansion of Embryonic and Adult Neural Stem Cells by In Utero Electroporation or Viral Stereotaxic Injection

Somatic stem cells can divide to generate additional stem cells (expansion) or more differentiated cell types (differentiation), which is fundamental for tissue formation during embryonic development and tissue homeostasis during adulthood 1. Currently, great efforts are invested towards controlling the switch of somatic stem cells from expansion to differentiation because this is thought to be fundamental for developing novel strategies for regenerative medicine 1,2. However, a major challenge in the study and use of somatic stem cell is that their expansion has been proven very difficult to control.
Here we describe a system that allows the control of neural stem/progenitor cell (altogether referred to as NSC) expansion in the mouse embryonic cortex or the adult hippocampus by manipulating the expression of the cdk4/cyclinD1 complex, a major regulator of the G1 phase of the cell cycle and somatic stem cell differentiation 3,4. Specifically, two different approaches are described by which the cdk4/cyclinD1 complex is overexpressed in NSC in vivo. By the first approach, overexpression of the cell cycle regulators is obtained by injecting plasmids encoding for cdk4/cyclinD1 in the lumen of the mouse telencephalon followed by in utero electroporation to deliver them to NSC of the lateral cortex, thus, triggering episomal expression of the transgenes 5-8. By the second approach, highly concentrated HIV-derived viruses are stereotaxically injected in the dentate gyrus of the adult mouse hippocampus, thus, triggering constitutive expression of the cell cycle regulators after integration of the viral construct in the genome of infected cells 9. Both approaches, whose basic principles were already described by other video protocols 10-14, were here optimized to i) reduce tissue damage, ii) target wide portions of very specific brain regions, iii) obtain high numbers of manipulated cells within each region, and iv) trigger high expression levels of the transgenes within each cell. Transient overexpression of the transgenes using the two approaches is obtained by different means i.e. by natural dilution of the electroporated plasmids due to cell division or tamoxifen administration in Cre-expressing NSC infected with viruses carrying cdk4/cyclinD1 flanked by loxP sites, respectively 9,15.
These methods provide a very powerful platform to acutely and tissue-specifically manipulate the expression of any gene in the mouse brain. In particular, by manipulating the expression of the cdk4/cyclinD1 complex, our system allows the temporal control of NSC expansion and their switch to differentiation, thus, ultimately increasing the number of neurons generated in the mammalian brain. Our approach may be critically important for basic research and using somatic stem cells for therapy of the mammalian central nervous system while providing a better understanding of i) stem cell contribution to tissue formation during development, ii) tissue homeostasis during adulthood, iii) the role of adult neurogenesis in cognitive functions, and perhaps, iv) better using somatic stem cells in models of neurodegenerative diseases.

Expansion of Embryonic and Adult Neural Stem Cells by In Utero Electroporation or Viral Stereotaxic Injection

Controlling the expansion of somatic stem cells is a major factor hampering their study and use in therapy. Here we describe a system to temporally control neural stem cells expansion during development and adulthood, which can be used to increase the number of neurons generated in the mouse brain.

Ampliamento della embrionali e cellule staminali neurali adulte per<em&gt; In Utero</em&gt; Elettroporazione o Viral iniezione stereotassica

Somatic stem cells can divide to generate additional stem cells (expansion) or more differentiated cell types (differentiation), which is fundamental for ...

Isolation and Culture of Neural Crest Cells from Embryonic Murine Neural Tube

The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to mesenchymal transition (EMT) and migrates throughout the embryo, giving rise to diverse cell types 1-3. NC also has the unique ability to influence the differentiation and maturation of target organs4-6. When explanted in vitro, NC progenitors undergo self-renewal, migrate and differentiate into a variety of tissue types including neurons, glia, smooth muscle cells, cartilage and bone. 
NC multipotency was first described from explants of the avian neural tube7-9. In vitro isolation of NC cells facilitates the study of NC dynamics including proliferation, migration, and multipotency. Further work in the avian and rat systems demonstrated that explanted NC cells retain their NC potential when transplanted back into the embryo10-13. Because these inherent cellular properties are preserved in explanted NC progenitors, the neural tube explant assay provides an attractive option for studying the NC in vitro. 
To attain a better understanding of the mammalian NC, many methods have been employed to isolate NC populations. NC-derived progenitors can be cultured from post-migratory locations in both the embryo and adult to study the dynamics of post-migratory NC progenitors11,14-20, however isolation of NC progenitors as they emigrate from the neural tube provides optimal preservation of NC cell potential and migratory properties13,21,22. Some protocols employ fluorescence activated cell sorting (FACS) to isolate a NC population enriched for particular progenitors11,13,14,17. However, when starting with early stage embryos, cell numbers adequate for analyses are difficult to obtain with FACS, complicating the isolation of early NC populations from individual embryos. Here, we describe an approach that does not rely on FACS and results in an approximately 96% pure NC population based on a Wnt1-Cre activated lineage reporter23. 
The method presented here is adapted from protocols optimized for the culture of rat NC11,13. The advantages of this protocol compared to previous methods are that 1) the cells are not grown on a feeder layer, 2) FACS is not required to obtain a relatively pure NC population, 3) premigratory NC cells are isolated and 4) results are easily quantified. Furthermore, this protocol can be used for isolation of NC from any mutant mouse model, facilitating the study of NC characteristics with different genetic manipulations. The limitation of this approach is that the NC is removed from the context of the embryo, which is known to influence the survival, migration and differentiation of the NC2,24-28.

Isolation of embryonic neural crest from the neural tube facilitates the use of in vitro methods for studying migration, self-renewal, and multipotency of neural crest.

Isolamento e la coltura delle cellule della cresta neurale da Embryonic Murine tubo neurale

The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to ...

In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons

The brain's ability to change in response to experience is essential for healthy brain function, and abnormalities in this process contribute to a variety of brain disorders1,2. To better understand the mechanisms by which brain circuits react to an animal's experience requires the ability to monitor the experience-dependent molecular changes in a given set of neurons, over a prolonged period of time, in the live animal. While experience and associated neural activity is known to trigger gene expression changes in neurons1,2, most of the methods to detect such changes do not allow repeated observation of the same neurons over multiple days or do not have sufficient resolution to observe individual neurons3,4. Here, we describe a method that combines in vivo two-photon microscopy with a genetically encoded fluorescent reporter to track experience-dependent gene expression changes in individual cortical neurons over the course of day-to-day experience. 
One of the well-established experience-dependent genes is Activity-regulated cytoskeletal associated protein (Arc)5,6. The transcription of Arc is rapidly and highly induced by intensified neuronal activity3, and its protein product regulates the endocytosis of glutamate receptors and long-term synaptic plasticity7. The expression of Arc has been widely used as a molecular marker to map neuronal circuits involved in specific behaviors3. In most of those studies, Arc expression was detected by in situ hybridization or immunohistochemistry in fixed brain sections. Although those methods revealed that the expression of Arc was localized to a subset of excitatory neurons after behavioral experience, how the cellular patterns of Arc expression might change with multiple episodes of repeated or distinctive experiences over days was not investigated. 
In vivo two-photon microscopy offers a powerful way to examine experience-dependent cellular changes in the living brain8,9. To enable the examination of Arc expression in live neurons by two-photon microscopy, we previously generated a knock-in mouse line in which a GFP reporter is placed under the control of the endogenous Arc promoter10. This protocol describes the surgical preparations and imaging procedures for tracking experience-dependent Arc-GFP expression patterns in neuronal ensembles in the live animal. In this method, chronic cranial windows were first implanted in Arc-GFP mice over the cortical regions of interest. Those animals were then repeatedly imaged by two-photon microscopy after desired behavioral paradigms over the course of several days. This method may be generally applicable to animals carrying other fluorescent reporters of experience-dependent molecular changes4.

In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons

Experience-dependent molecular changes in neurons are essential for the brain's ability to adapt in response to behavioral challenges. An in vivo two-photon imaging method is described here that allows the tracking of such molecular changes in individual cortical neurons through genetically encoded reporters.

In Vivo a due fotoni di imaging dei cambi molecolari esperienza-dipendenti nei neuroni corticali

The brain's ability to change in response to experience is essential for healthy brain function, and abnormalities in this process contribute to a variety ...

Imaging Intracellular Ca2+ Signals in Striatal Astrocytes from Adult Mice Using Genetically-encoded Calcium Indicators

Astrocytes display spontaneous intracellular Ca2+ concentration fluctuations ([Ca2+]i) and in several settings respond to neuronal excitation with enhanced [Ca2+]i signals. It has been proposed that astrocytes in turn regulate neurons and blood vessels through calcium-dependent mechanisms, such as the release of signaling molecules. However, [Ca2+]i imaging in entire astrocytes has only recently become feasible with genetically encoded calcium indicators (GECIs) such as the GCaMP series. The use of GECIs in astrocytes now provides opportunities to study astrocyte [Ca2+]i signals in detail within model microcircuits such as the striatum, which is the largest nucleus of the basal ganglia. In the present report, detailed surgical methods to express GECIs in astrocytes in vivo, and confocal imaging approaches to record [Ca2+]i signals in striatal astrocytes in situ, are described. We highlight precautions, necessary controls and tests to determine if GECI expression is selective for astrocytes and to evaluate signs of overt astrocyte reactivity. We also describe brain slice and imaging conditions in detail that permit reliable [Ca2+]i imaging in striatal astrocytes in situ. The use of these approaches revealed the entire territories of single striatal astrocytes and spontaneous [Ca2+]i signals within their somata, branches and branchlets. The further use and expansion of these approaches in the striatum will allow for the detailed study of astrocyte [Ca2+]i signals in the striatal microcircuitry.

Imaging Intracellular Ca2+ Signals in Striatal Astrocytes from Adult Mice Using Genetically-encoded Calcium Indicators

The properties and functions of astrocyte intracellular Ca2+ signals in the striatum remain incompletely explored. We describe methods to express genetically encoded calcium indicators in striatal astrocytes using adeno-associated viruses of serotype 2/5 (AAV2/5), as well as procedures to reliably image Ca2+ signals within striatal astrocytes in situ.

Imaging intracellulare Ca<sup&gt; 2+</sup&gt; Segnali di striatale astrociti da topi adulti utilizzando indicatori di calcio geneticamente codificate

Astrocytes display spontaneous intracellular Ca2+ concentration fluctuations ([Ca2+]i) and in several settings respond to neuronal excitation with ...

The Detection of 5-Hydroxymethylcytosine in Neural Stem Cells and Brains of Mice

Multiple&#160;DNA modifications have been identified in the mammalian genome. Of that, 5-methylcytosine and 5-hydroxymethylcytosine-mediated epigenetic mechanisms have been intensively studied. 5-hydroxymethylcytosine displays dynamic features during embryonic and postnatal development of the brain, plays a regulatory function in gene expression, and is involved in multiple neurological disorders. Here, we describe the detailed methods including immunofluorescence staining and&#160;DNA dot-blot to detect 5-hydroxymethylcytosine in cultured cells and brain tissues of mouse.

Here, we present a protocol to detect 5-hydroxymethylcytosine in cells and brain tissues, utilizing immunofluorescence staining and DNA dot-blot methods.

Il rilevamento di 5-Hydroxytethylcytosine in cellule staminali neurali e cervelli di topi

Multiple&#160;DNA modifications have been identified in the mammalian genome. Of that, 5-methylcytosine and 5-hydroxymethylcytosine-mediated epigenetic ...

Neuronal Differentiation from Mouse Embryonic Stem Cells In vitro

The neural differentiation of mouse embryonic stem cells (mESCs) is a potential tool for elucidating the key mechanisms involved in neurogenesis and potentially aid in regenerative medicine. Here, we established an efficient and low cost method for neuronal differentiation from mESCs in vitro, using the strategy of combinatorial screening. Under the conditions defined here, the 2-day embryoid body formation + 6-day retinoic acid induction protocol permits fast and efficient differentiation from mESCs into neural precursor cells (NPCs), as seen by the formation of well-stacked and neurite-like A2lox and 129 derivatives that are Nestin positive. The healthy state of embryoid bodies and the timepoint at which retinoic acid (RA) is applied, as well as the RA concentrations, are critical in the process. In the subsequent differentiation from NPCs into neurons, N2B27 medium II (supplemented by Neurobasal medium) could better support the long term maintenance and maturation of neuronal cells. The presented method is highly efficiency, low cost and easy to operate, and can be a powerful tool for neurobiology and developmental biology research.

Here, we established a low cost and easy to operate method that directs fast and efficient differentiation from embryonic stem cells into neurons. This method is suitable for popularization among laboratories and can be a useful tool for neurological research.

Differenziazione neuronale dalle cellule staminali embrionali del topo in vitro

The neural differentiation of mouse embryonic stem cells (mESCs) is a potential tool for elucidating the key mechanisms involved in neurogenesis and ...

In vitro Modeling for Neurological Diseases using Direct Conversion from Fibroblasts to Neuronal Progenitor Cells and Differentiation into Astrocytes

Research on neurological disorders focuses primarily on the impact of neurons on disease mechanisms. Limited availability of animal models severely impacts the study of cell type specific contributions to disease. Moreover, animal models usually do not reflect variability in mutations and disease courses seen in human patients. Reprogramming methods for generation of induced pluripotent stem cells (iPSCs) have revolutionized patient specific research and created valuable tools for studying disease mechanisms. However, iPSC technology has disadvantages such as time, labor commitment, clonal selectivity and loss of epigenetic markers. Recent modifications of these methods allow more direct generation of cell lineages or specific cell types, bypassing clonal isolation or a pluripotent stem cell state. We have developed a rapid direct conversion method to generate induced Neuronal Progenitor Cells (iNPCs) from skin fibroblasts utilizing retroviral vectors in combination with neuralizing media. The iNPCs can be differentiated into neurons (iNs) oligodendrocytes (iOs) and astrocytes (iAs). iAs production facilitates rapid drug and disease mechanism testing as differentiation from iNPCs only takes 5 days. Moreover, iAs are easy to work with and are generated in pure populations at large numbers. We developed a highly reproducible co-culture assay using mouse GFP+ neurons and patient derived iAs to evaluate potential therapeutic strategies for numerous neurological and neurodegenerative disorders. Importantly, the iA assays are scalable to 384-well format facilitating the evaluation of multiple small molecules in one plate. This approach allows simultaneous therapeutic evaluation of multiple patient cell lines with diverse genetic background. Easy production and storage of iAs and capacity to screen multiple compounds in one assay renders this methodology adaptable for personalized medicine.

We describe a protocol to reprogram human skin-derived fibroblasts into induced Neuronal Progenitor Cells (iNPCs), and their subsequent differentiation into induced Astrocytes (iAs). This method leads to fast and reproducible generation of iNPCs and iAs in large quantities.

Modellazione in vitro per malattie neurologiche utilizzando la conversione diretta dai fibroblasti alle cellule progenitrici neuronali e la differenziazione in astrociti

Research on neurological disorders focuses primarily on the impact of neurons on disease mechanisms. Limited availability of animal models severely ...