Vorremmo estendere il nostro sincero grazie a Dr. Ben Fowler per il suo aiuto tecnico con gli esperimenti TEM.

Questo protocollo segue le linee guida del Comitato di revisione di Università di Oklahoma Health Sciences Center/istituzionale (IRB n. 4509). Tutte le parti del protocollo ha incontrato i principi della dichiarazione di Helsinki. Campioni corneali sono stati ottenuti dallo sviluppo nazionale e Research Institute (NDRI) e la banca degli occhi Lions di Oklahoma.
1. isolamento di cellule primarie
<ol><li>Al ricevimento dei campioni di tessuto cornea umana, trasferire i tessuti in un 21,5 cm2 capsula di Petri contenente 2 mL di soluzione tampone fosfato sterile di Dulbecco (DPBS) (1x).</li>
	<li>Raschiare e rimozione dell'epitelio corneale posizionando la cornea cupola a faccia in su. Per garantire la rimozione completa, grattare via lo strato epiteliale accuratamente con una lama di rasoio ad un angolo di 45°. Successivamente, capovolgere la cornea cupola a faccia in giù e raschiare accuratamente l'endotelio dallo stroma con una lama di rasoio ad un angolo di 45° per garantire la rimozione completa. Lavare il tessuto stromal con DPBS.</li>
	<li>Tagliare i tessuti stromali in piccoli pezzi, usando una lama chirurgica del numero 10, tenere i pezzi stromali bagnati a tutti i tempi con DPBS. Raccogliere pezzi stromal con pinze sterili e posto in un matraccio di cultura T25 senza mezzi di comunicazione (4 o 5 pezzi di tessuto di 2 x 2 mm per fiaschetta).</li>
	<li>Consentire gli espianti di aderire al fondo del matraccio a 37 ° C per circa 30-40 min. Una volta aderito, aggiungere lentamente il mezzo essenziale minimo di Eagle (EMEM) contenente 10% siero bovino fetale (FBS) e 1% antibiotico/Antimycotic al pallone senza disturbare gli espianti.</li>
	<li>Posizionare delicatamente il pallone nell'incubatore a 37 ° C, 5% CO2. Lasciare gli espianti indisturbato fino a quando le cellule iniziano a isolare e la migrazione nel pallone. Dopo circa 2-4 settimane, le cellule dovrebbero raggiungere la confluenza di 100%. Sulla confluenza di 100%, le cellule del passaggio rimuovendo i mezzi di coltura del tessuto e lavare le cellule con DPBS.</li>
	<li>Aggiungere tripsina alle cellule e quindi li Incubare a 37° C. Dopo circa 5 minuti, Mostra le cellule nell'ambito di microscopia per confermare che hanno staccato e poi fermare la proteolisi aggiungendo media fresco.</li>
	<li>Trasferire la sospensione cellulare in una provetta conica da 15 mL per centrifugazione a 1.000 x g. eliminare il surnatante con attenzione senza disturbare il pellet e sospendere le cellule in EMEM fresco 10% FBS 1% antibiotico. Contare le celle e seme circa 1 x 106 cellule nel matraccio di cultura T75 per un'ulteriore espansione con EMEM fresco 1% FBS 1% antibiotico.</li>
</ol>2. primaria HCF cultura e costrutti 3D Assembly
<ol><li>Per assemblare 3D costrutti da espianti EMEM precedentemente coltivate in 10% FBS 1% antibiotico/Antimycotic, corridoio e conteggio HCF.</li>
	<li>Semi di circa 1 x 106 cellule/pozzetto di HCF primario su inserti di membrana in policarbonato con pori 0,4 µm dai costrutti 3D, insieme con 1,5 mL di EMEM fresco 10% FBS 1% antibiotico/Antimycotic nella parte superiore del costrutto. Aggiungere un altro 1,5 mL di stesso supporto nella parte inferiore di ogni costrutto.</li>
	<li>Dopo 24 h di semina delle cellule, della coltura delle cellule con EMEM 10% FBS 1% antibiotico/Antimycotic, stimolato con 0,5 mM acido 2-O-α-D-glucopyranosyl-L-ascorbic (vitamina C) da aggiungere 1,5 mL in alto a sinistra e 1,5 mL sul fondo di ogni costrutto.</li>
	<li>Mantenere le colture in un incubatore a 37 ° C, 5% CO2 per 3 settimane e fornire mezzi freschi ogni altro giorno durante l'intero periodo di studio. Nessun passaggio ulteriore è necessaria.</li>
</ol>3. differenziazione e co-colture delle cellule
<ol><li>Dopo 3 settimane, aggiungere 8 x 103 cellule/pozzetto di cellule di neuroblastoma umano SH-SY5Y sulla cima il 3D precedentemente assemblato costruisce contenente 1,5 mL di EMEM contenente 10% FBS, 1% antibiotico/Antimycotic e 0,5 mM 2-O-α-D-glucopyranosyl-L-ascorbic acido (vitamina C).<ol>
<li>Consentire le cellule di neuroblastoma SH-SY5Y a crescere sopra le cellule stromal di cornea per almeno 24 ore prima dell'inizio della differenziazione cellulare.</li>
	</ol>
</li>
	<li>Avviare la differenziazione delle cellule SH-SY5Y stimolando le cellule con EMEM contenente 1% FBS e 1,5 mL di 10 µM acido retinoico in cima il costrutto. Aggiungere 1,5 mL di EMEM 10% FBS 1% antibiotico/Antimycotic 0,5 mM 2-O-α-D-glucopyranosyl-L-ascorbic acido (vitamina C) alla parte inferiore del costrutto. Nota che l'acido retinoico va effettuata al buio.<ol>
<li>Continuare a coltivare le cellule in questa media di differenziazione per 5 giorni.</li>
	</ol>
</li>
	<li>Quando le cellule raggiungono la fase di differenziazione, passare le cellule a 1,5 mL di terreno privo di siero contenente 2 nM di fattore neurotrophic cervello-derivato (BDNF) e 1% antibiotico/Antimycotic aggiunto ai EMEM, aggiungendo alla parte superiore del costrutto. Aggiungere 1,5 mL di EMEM 10% FBS 1% antibiotico/Antimycotic 0,5 mM 2-O-α-D-glucopyranosyl-L-ascorbic acido (vitamina C) alla parte inferiore del costrutto. Si noti che il passo BDNF deve essere eseguito nel buio.</li>
	<li>Coltura delle cellule per 2 giorni aggiuntivi prima dell'elaborazione per qualsiasi ulteriore analisi come indicato nella tabella 1.</li>
</ol>

<ol>
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L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Corneal+tissue+engineering:+recent+advances+and+future+perspectives.">Corneal tissue engineering: recent advances and future perspectives.</a> Tissue Eng Part B Rev. 21 (3), 278-287 (2015).</li><li>Shafaie, S., Hutter, V., Cook, M. T., Brown, M. B., Chau, D. Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Vitro+Cell+Models+for+Ophthalmic+Drug+Development+Applications.">In Vitro Cell Models for Ophthalmic Drug Development Applications.</a> BioResearch Open Access. 5 (1), 94-108 (2016).</li><li>Shaheen, B. S., Bakir, M., Jain, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Corneal+nerves+in+health+and+disease.">Corneal nerves in health and disease.</a> Surv Ophthalmol. 59 (3), 263-285 (2014).</li><li>Beuerman, R. W., Schimmelpfennig, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensory+denervation+of+the+rabbit+cornea+affects+epithelial+properties.">Sensory denervation of the rabbit cornea affects epithelial properties.</a> Exp Neurol. 69 (1), 196-201 (1980).</li><li>Heigle, T. J., Pflugfelder, S. 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A., Mudera, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collagen+stiffness+regulates+cellular+contraction+and+matrix+remodeling+gene+expression.">Collagen stiffness regulates cellular contraction and matrix remodeling gene expression.</a> J Biomed Mater Res A. 83 (3), 887-894 (2007).</li><li>Ruberti, J. W., Zieske, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prelude+to+corneal+tissue+engineering+-+gaining+control+of+collagen+organization.">Prelude to corneal tissue engineering - gaining control of collagen organization.</a> Prog Retin Eye Res. 27 (5), 549-577 (2008).</li><li>Karamichos, D., Guo, X. Q., Hutcheon, A. E., Zieske, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+corneal+fibrosis:+an+in+vitro+model.">Human corneal fibrosis: an in vitro model.</a> Invest Ophthalmol Vis Sci. 51 (3), 1382-1388 (2010).</li><li>Chen, F. M., Liu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advancing+biomaterials+of+human+origin+for+tissue+engineering.">Advancing biomaterials of human origin for tissue engineering.</a> Prog Polym Sci. 53, 86-168 (2016).</li><li>Priyadarsini, S., Sarker-Nag, A., Rowsey, T. G., Ma, J. X., Karamichos, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+of+a+3D+In+Vitro+Model+to+Accelerate+the+Development+of+Human+Therapies+against+Corneal+Diabetes.">Establishment of a 3D In Vitro Model to Accelerate the Development of Human Therapies against Corneal Diabetes.</a> PLoS One. 11 (12), e0168845 (2016).</li><li>Karamichos, D., Hjortdal, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Keratoconus:+tissue+engineering+and+biomaterials.">Keratoconus: tissue engineering and biomaterials.</a> J Funct Biomater. 5 (3), 111-134 (2014).</li><li>Wilson, S. L., Yang, Y., El Haj, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Corneal+Stromal+Cell+Plasticity:+In+Vitro+Regulation+of+Cell+Phenotype+Through+Cell-Cell+Interactions+in+a+Three-Dimensional+Model.">Corneal Stromal Cell Plasticity: In Vitro Regulation of Cell Phenotype Through Cell-Cell Interactions in a Three-Dimensional Model.</a> Tissue Engineering Part A. 20 (1-2), 225-238 (2014).</li><li>Proulx, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reconstruction+of+a+human+cornea+by+the+self-assembly+approach+of+tissue+engineering+using+the+three+native+cell+types.">Reconstruction of a human cornea by the self-assembly approach of tissue engineering using the three native cell types.</a> Molecular Vision. 16 (234-236), 2192-2201 (2010).</li><li>Gonzalez-Andrades, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+of+a+novel+in+vitro+model+of+stratified+epithelial+wound+healing+with+barrier+function.">Establishment of a novel in vitro model of stratified epithelial wound healing with barrier function.</a> Sci Rep. 6, 19395 (2016).</li><li>Hopkins, A. M., DeSimone, E., Chwalek, K., Kaplan, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+in+vitro+modeling+of+the+central+nervous+system.">3D in vitro modeling of the central nervous system.</a> Prog Neurobiol. 125, 1-25 (2015).</li><li>Schulz, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+Corneal+Cell-Based+Microenvironment+as+Prerequisite+for+Balanced+3D+Corneal+Epithelial+Morphogenesis:+A+Promising+Animal+Experiment-Abandoning+Tool+in+Ophthalmology.">Natural Corneal Cell-Based Microenvironment as Prerequisite for Balanced 3D Corneal Epithelial Morphogenesis: A Promising Animal Experiment-Abandoning Tool in Ophthalmology.</a> Tissue Engineering Part C-Methods. 20 (4), 297-307 (2014).</li><li>Gao, J., Wang, Y., Zhao, X., Chen, P., Xie, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MicroRNA-204-5p-Mediated+Regulation+of+SIRT1+Contributes+to+the+Delay+of+Epithelial+Cell+Cycle+Traversal+in+Diabetic+Corneas.">MicroRNA-204-5p-Mediated Regulation of SIRT1 Contributes to the Delay of Epithelial Cell Cycle Traversal in Diabetic Corneas.</a> Invest Ophthalmol Vis Sci. 56 (3), 1493-1504 (2015).</li><li>Koulikovska, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+regeneration+of+corneal+tissue+via+a+bioengineered+collagen+construct+implanted+by+a+nondisruptive+surgical+technique.">Enhanced regeneration of corneal tissue via a bioengineered collagen construct implanted by a nondisruptive surgical technique.</a> Tissue Eng Part A. 21 (5-6), 1116-1130 (2015).</li><li>Ljubimov, A. V., Saghizadeh, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progress+in+corneal+wound+healing.">Progress in corneal wound healing.</a> Progress in retinal and eye research. 49, 17-45 (2015).</li><li>Zieske, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+matrix+and+wound+healing.">Extracellular matrix and wound healing.</a> Curr Opin Ophthalmol. 12 (4), 237-241 (2001).</li><li>Karamichos, D., Hutcheon, A. E., Zieske, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transforming+growth+factor-beta3+regulates+assembly+of+a+non-fibrotic+matrix+in+a+3D+corneal+model.">Transforming growth factor-beta3 regulates assembly of a non-fibrotic matrix in a 3D corneal model.</a> J Tissue Eng Regen Med. 5 (8), e228-e238 (2011).</li><li>Karamichos, D., Lakshman, N., Petroll, W. 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Gli autori non dichiarano concorrenti interessi finanziari.

Diversi studi si sono concentrati sullo sviluppo di vari modelli animali che possono aiutare a sviluppare una migliore comprensione delle malattie della cornea così come scoprire i trattamenti. Tuttavia, un notevole valore agli esseri umani da questi studi non è stato verificato. Ad oggi, vari modelli in vitro sono sviluppati e ampiamente studiati a causa della loro notevole importanza clinica. Il nostro modello precedentemente stabilito 3D in vitro è un innovativo sistema significativamente contribuisce agli avanzamenti della scienza medica nella ricerca sulla visione e Mostra Immacolata capacità di ricapitolare in vivo eventi in vitro28 , 29 , 30. l'obiettivo di questo protocollo è quello di sviluppare la prossima generazione di questo in vitro corneale modello che può essere utilizzato per lo studio dei meccanismi cellulari e molecolari delle complicazioni connesse con patologie corneali quali diabetici keratopathy, cheratocono e Fuchs. Tale avanzamento potrebbe fornire solide fondamenta verso la scoperta di nuovi trattamenti che sono molto necessari clinicamente.
Questo modello può aiutare nell'identificazione di diverse alterazioni strutturali e cellulari che si svolgono in DM e altre malattie della cornea. Questo fornisce notevoli implicazioni, tra cui la possibilità per lo screening per queste malattie in una fase iniziale di potenzialmente aiutare con gestione della malattia. Il modello proposto qui è semplice, ma è altamente innovativo. Uno dei vantaggi più significativi è che le cellule stromal corneale sono autorizzate a secernere e assemblare le proprie ECM anziché essere seminate su un ambiente artificiale. Inoltre, i nervi sono consentiti per differenziare più accuratamente interazioni di nervo stromal corneale di modello. Quindi, questo metodo fornisce la possibilità di studiare lo stroma cornea umano e rete del nervo, come pure le cellule che si trovano all'interno dell'ambiente di stroma. Questa piattaforma cultura permetterà le indagini future delle complesse interazioni cellula-cellula e cellula-matrice che influenzano gli stati malati della cornea. Questo approccio di modello 3D in vitro è previsto per fornire migliorato e romanzo spaccato meccanismo di malattia, soprattutto se paragonato ad corrente convenzionale cultura sistemi o modelli animali.
La generazione descritta di questo modello 3D in vitro spianerà la strada per il futuro trattamento terapeutico e scoperte.

Nel corpo umano, la cornea è il tessuto più densamente innervato. I nervi sono responsabili di varie sensazioni come touch, dolore, temperatura e hanno anche un ruolo essenziale nella guarigione delle ferite, lampeggiano i riflessi, tear produzione e secrezione5,6,7. Nella cornea, tronchi del nervo stromal derivano dal plesso limbal e immettere lo stroma cornea periferico radialmente. L'organizzazione di stromal del nervo è parallelo le lamelle collagene e ulteriore diramazione in fasci più piccoli come si procede verso il stroma superficiale5,8. Le fibre nervose ulteriormente penetrare lo strato epiteliale e così, lo stimolo è ampiamente sparso attraverso l'epitelio corneale e lo stroma. Di conseguenza, lo stimolo ha un ruolo essenziale nello stato sano e malato della cornea. In questo protocollo, riveliamo l'avanzamento di un modello di romanzo 3D in vitro , che è il primo del suo genere per simulare le interazioni di stromal-nervo in vivo . La linea di cellule SH-SY5Y era utilizzata per questo studio, in quanto è una delle linee più affermate, ben caratterizzate utilizzate per studiare la crescita neuronale. La linea di cellule SH-SY5Y è stato descritta per produrre sia aderente di substrato (S-type) e neuroblastic (tipo N) che le cellule possono subire transdifferenziazione9. Di conseguenza, anche se questa linea cellulare è derivata da una selezione di triple consecutive subclone di cellule di tipo N, che contiene anche un piccolo numero di cellule di tipo S in grado di subire il differenziamento in neuroni attraverso l'uso di retinoico acido e cervello-derivato neurotrophic factor9. Questo fornisce uno strumento che può portare a una migliore comprensione delle complicazioni corneale connesse con retinopatia diabetica (DM) e altre malattie oculari. A causa di difficoltà associate all'ottenimento e coltura neuroni da pazienti con malattia oculare, questo modello 3D in vitro fornisce notevoli implicazioni nello studio delle interazioni neuronali e segnalazione con lo stroma corneale.
Circostanze malate spesso colpiscono vari tessuti del corpo ad una scala molto grande, che porta ad una qualità della vita compromessa. Le distrofie oculare sono complicazioni comuni spesso associate a malattie sistemiche e portare alla perdita dell'acuità visiva o anche permanente della vista. Studi completi sono spesso essenziali per una migliore comprensione della condizione di malattia, come pure gli effetti a livello cellulare basale. Per studiare gli effetti di tali malattie, sono stati sviluppati vari modelli in vivo e in vitro con l'aiuto di applicazioni di ingegneria tissutale. Applicazioni di ingegneria del tessuto corneale hanno raccolto grande interesse in vari settori della scienza10,11,12,13,14, ma ci sono ancora notevoli limitazioni durante effettiva applicazione, tra cui corneale dell'innesto respingimenti, infezioni e cicatrici10,11,12,13,14. Ci sono diversi studi che hanno sviluppato con successo e stabilite varie in vitro modelli3,15,16,17,18, 19,20,21,22,23,24,25,26. I modelli 3D in vitro sono i più promettenti e di grande interesse scientifico. Modelli 3D sono noti per meglio rispecchiare il in vivo eventi cellulari e fisiologiche che sono critici durante la fibrosi e ferita guarigione15,27,28,29. Questi modelli in vitro giocano un ruolo fondamentale nella ricerca di nuovi approcci terapeutici per il trattamento di diverse patologie tra cui le complicazioni corneali. Nonostante il ruolo critico dell'innervazione nelle funzioni corneale, piccoli sforzi compiuti per promuovere la proliferazione di nervo periferico all'interno di costrutti tessutale corneale2,3. Tuttavia, i costrutti di cella proposto 3D in vitro imitano il tessuto bersaglio al fine di conseguire la funzionalità del tessuto desiderato.
Mentre keratopathy diabetica è un'applicazione evidente per il modello descritto qui dovuto i difetti di un neurone, ci sono parecchie altre malattie corneali che possono beneficiare di un modello umano in vitro compreso le distrofie cheratocono e Fuchs. Il nostro modello 3D emerge da questa prospettiva e propone lo sviluppo di una rappresentazione in vitro del tessuto corneale per valutare la somministrazione di farmaci e la sicurezza dei nuovi farmaci oculari.

<table>
	<tbody>
		<tr>
			<td>Healthy corneal tissue</td>
			<td>NDRI</td>
			<td></td>
			<td>Samples from donors with no ocular trauma or systemic disease</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s Phosphate Buffered Solution (1X)</td>
			<td>Gibco by Life Technologies</td>
			<td>14190-144</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile forceps</td>
			<td>Fischer Scientific</td>
			<td>13-812-42</td>
			<td>Fisherbrand Dissecting Extra-Fine-Pointed Splinter Forceps</td>
		</tr>
		<tr>
			<td>Single edge razor blades</td>
			<td>Personna</td>
			<td>270100</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile surgical scalpel blades No.10</td>
			<td>Feather Surgical Blade</td>
			<td>2976#10</td>
			<td></td>
		</tr>
		<tr>
			<td>Eagle&#8217;s Minimum Essential Medium</td>
			<td>ATCC</td>
			<td>30-2003</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Atlanta Biologicals</td>
			<td>S11550</td>
			<td>10% FBS is required for media preparation</td>
		</tr>
		<tr>
			<td>Antibiotic-Antimycotic (100X)</td>
			<td>Gibco by Life Technologies</td>
			<td>15240-062</td>
			<td>1% Antibiotic-Antimycotic is required for media preparation</td>
		</tr>
		<tr>
			<td>0.05% Trypsin EDTA(1X)</td>
			<td>Gibco by Life Technologies</td>
			<td>25300062</td>
			<td></td>
		</tr>
		<tr>
			<td>Polycarbonate membrane inserts with 0.4-&#956;m pores</td>
			<td>Corning Costar</td>
			<td>3412</td>
			<td></td>
		</tr>
		<tr>
			<td>2-O-&#945;-Dglucopyranosyl-L-ascorbic acid (Vitamin C)</td>
			<td>Sigma-Aldrich</td>
			<td>SMB00390-14</td>
			<td>A concentration of 0.5 mM should be used for the study</td>
		</tr>
		<tr>
			<td>Wax block</td>
			<td>VWR</td>
			<td>50-949-027</td>
			<td></td>
		</tr>
		<tr>
			<td>SH-SY5Y Neuroblastoma cells</td>
			<td>ATCC</td>
			<td>SHSY5YATCC CRL-2266</td>
			<td></td>
		</tr>
		<tr>
			<td>Retinoic Acid</td>
			<td>Sigma-Aldrich</td>
			<td>SRP3014-10UG</td>
			<td>Final concentration of 10uM needs to be used</td>
		</tr>
		<tr>
			<td>BDNF</td>
			<td>Sigma-Aldrich</td>
			<td>R2625-100MG</td>
			<td>Final concentration of 2nM needs to be used</td>
		</tr>
		<tr>
			<td>Dimethyl Sulfoxide(DMSO)</td>
			<td>VWR-Alfa Aesar</td>
			<td>67-68-5</td>
			<td>Ultra Pure Grade-Sterile DMSO to be used</td>
		</tr>
		<tr>
			<td>Thermo Scientific Nunc Cell Culture Treated EasYFlasks (T25)</td>
			<td>Fisher Scientific</td>
			<td>12-565-351</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermo Scientific Nunc Cell Culture Treated EasYFlasks (T75)</td>
			<td>Fisher Scientific</td>
			<td>12-565-349</td>
			<td></td>
		</tr>
	</tbody>
</table>

corneal tissue engineering: an in vitro model of the stromal-nerve interactions of the human cornea

Ingegneria tissutale ha guadagnato riconoscimento sostanza a causa della forte domanda per le sostituzioni di cornea umana con circa 10 milioni di persone in tutto il mondo soffrono di perdita di visione corneale1. Per rispondere alla domanda di cornee umane vitali, progressi significativi nel tessuto di tridimensionale (3D) ingegneria è stato fatto2,3,4. Questi gamma di modelli di cornea da sistemi monostrato semplice ai modelli multilivello, che conduce a 3D equivalenti corneale di pieno-spessore2.
Tuttavia, l'uso di una cornea tessutale 3D nel contesto dei modelli di malattia in vitro studiato per data non ha somiglianza con la struttura multistrato 3D tessuto corneale, funzione e la messa in rete di diversi tipi di cellule (cioè, nervo, epitelio, stroma ed endotelio)2,3. Inoltre, la domanda per i modelli di tessuti in vitro cornea è aumentata nel tentativo di ridurre la sperimentazione animale per i prodotti farmaceutici. Così, modelli più sofisticati sono tenuti a corrispondere meglio sistemi ai requisiti fisiologici umani e lo sviluppo di un modello che è più rilevante per la popolazione di pazienti è assolutamente necessario. Dato che più tipi di cellule nella cornea sono colpiti da malattie e distrofie, quali cheratocono, cheratopatia diabetica e Fuchs, questo modello include un modello 3D co-coltura di fibroblasti corneali umani primari (HCF) da donatori sani e neuroni da la linea di cellule SH-SY5Y. Questo ci permette per la prima volta studiare le interazioni tra i due tipi cellulari all'interno del tessuto cornea umano. Crediamo che questo modello potrebbe potenzialmente sezionare i meccanismi di fondo connessi con le interazioni di stromal-nervo di patologie corneali che presentano danni del nervo. Questo modello 3D rispecchia la natura di base anatomica e fisiologica del tessuto corneale in vivo e utilizzabile in futuro come uno strumento per indagare i difetti corneali così come l'efficacia di vari agenti di screening prima sperimentazione animale.

Figura 1 è una dettagliata immagine rappresentativa del modello di lavoro 3D in vitro . Nella prima fase, le cellule sono isolate dalle cornee umane. Quindi, sono cresciuti su una membrana di policarbonato e stimolati con vitamina C per assemblare una matrice 3D auto-secreta. Questo sistema di costrutto 3D induce la sintesi di un multistrato cellulare in vivo-come matrice stromale. Successivamente, le cellule di neuroblastoma sono seminate in cima le cellule stromal seguite avviando la differenziazione delle cellule neuronali. Questo porta alla co-coltura delle cellule stromale corneale e cellule neuronali differenziate nel modello 3D in vitro . Figura 2 è l'immagine di microscopia elettronica (TEM) di trasmissione ad alto ingrandimento del costrutto 3D auto-assemblato (Figura 2A) mostrando la membrana di policarbonato e le cellule stromal corneale seminato sulla parte superiore, che secernono una matrice auto-assemblata seguita da (Figura 2B) cellule neuronali differenziate seminato in alto mostra una disposizione stromal delle cellule neuronali. Le frecce nell'immagine mostrano le cellule neuronali. Dato il crosstalk diretto tra lo stroma cornea e cellule neuronali, crediamo che i giocatori chiavi che influenzano la regolazione dei difetti corneali presenti nello strato di stroma. Pertanto, questo modello presenta un neuroblastoma differenziazione SH-SY5Y umano neuronale in vitro modello cellule in una morfologia neuronale sostenibile attraverso la combinazione con il nostro modello 3D precedentemente stabilito di matrice extracellulare (ECM) coltura con vari fattori discriminanti. Così, abbiamo il sospetto che questo modello consentirà futuri studi delle differenze morfologiche e molecolari tra ECM sani e malati. Crediamo che questo modello di romanzo 3D in vitro aiuterà dissezionare aspetti cruciali delle interazioni stroma corneale-nervo associate a patologia corneale e spianare la strada per lo sviluppo di nuove terapie.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56308/56308fig1.jpg"> Figura 1: immagine illustrativo Mostra il modello di co-coltura 3D in vitro in maniera graduale. Questa immagine mostra l'isolamento delle cellule dalla cornea umana e cellule stromali seminate su una membrana di policarbonato, situato nel costrutto 3D, coltivate in EMEM e stimolato con vitamina c. Inoltre, le cellule neuronali differenziate sono indicate per essere seminato in cima le cellule stromal. <a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56308/56308fig1large.jpg" target="_blank">Clicca qui per visualizzare una versione più grande di questa figura.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56308/56308fig2.jpg"> Figura 2: Immagine TEM di alto ingrandimento del sistema 3D in vitro . (A) disposizione di cellule stromali in cima la membrana in policarbonato. (B) Seeded differenziato cellule neuronali in cima le cellule stromal. Scala bar = 500 nm. <a href="//cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56308/56308fig2large.jpg" target="_blank">Clicca qui per visualizzare una versione più grande di questa figura.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>Tecniche per l'analisi</td>
			<td>Potenziali implicazioni</td>
		</tr>
<tr>
<td>Reazione a catena della polimerasi quantitativa in tempo reale</td>
			<td>Indagare i marcatori del collagene (Col, Col III e Col V), marcatore fibrotica actina alfa-liscia del muscolo (α-SMA) e mediatori chiave nel DM come fattore di crescita insulino-1 (IGF-1) e si è ricevitore (IGF1-R)</td>
		</tr>
<tr>
<td>Microscopia elettronica a trasmissione</td>
			<td>Cambiamenti strutturali sono studiati come fibrille collagene e le interazioni cellula-ECM</td>
		</tr>
<tr>
<td>Immunofluorescenza</td>
			<td>Uso di anticorpi specifici chimicamente coniugato alla tintura fluorescente per indagare gli antigeni cellulari</td>
		</tr>
</tbody></table>Tabella 1: Tecniche di analisi.

Watch this Scientific Journal Video about Corneal Tissue Engineering: An In Vitro Model of the Stromal-nerve Interactions of the Human Cornea at JoVE.com

Corneal Tissue Engineering: An In Vitro Model of the Stromal-nerve Interactions of the Human Cornea

Questo protocollo descrive un romanzo tridimensionale in vitro modello, cui sono coltivate cellule stromal corneale e cellule neuronali differenziate insieme per assistere nell'esame e nella comprensione delle interazioni tra i due tipi cellulari.

Ingegneria tissutale corneale: Un In Vitro modello delle interazioni Stromal-nervo della Cornea umana

Tissue engineering has gained substantial recognition due to the high demand for human cornea replacements with an estimated 10 million people worldwide ...

corneal-tissue-engineering-an-vitro-model-stromal-nerve-interactions

Nanyang Technological University

Research

JoVE Journal

Developmental Biology

Corneal Tissue Engineering: An In Vitro Model of the Stromal-nerve Interactions of the Human Cornea

8.7K Views.  University of Oklahoma Health Sciences Center. Questo protocollo descrive un romanzo tridimensionale in vitro modello, cui sono coltivate cellule stromal corneale e cellule neuronali differenziate insieme per assistere nell'esame e nella comprensione delle interazioni tra i due tipi cellulari.

Video: Corneal Tissue Engineering: An In Vitro Model of the Stromal-nerve Interactions of the Human Cornea

Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye

The zebrafish model is an emerging system for the study of neuromuscular disorders. In the study of neuromuscular diseases, the integrity of the muscle membrane is a critical disease determinant. To date, numerous neuromuscular conditions display degenerating muscle fibers with abnormal membrane integrity; this is most commonly observed in muscular dystrophies. Evans Blue Dye (EBD) is a vital, cell permeable dye that is rapidly taken into degenerating, damaged, or apoptotic cells; in contrast, it is not taken up by cells with an intact membrane. EBD injection is commonly employed to ascertain muscle integrity in mouse models of neuromuscular diseases. However, such EBD experiments require muscle dissection and/or sectioning prior to analysis. In contrast, EBD uptake in zebrafish is visualized in live, intact preparations. Here, we demonstrate a simple and straightforward methodology for performing EBD injections and analysis in live zebrafish. In addition, we demonstrate a co-injection strategy to increase efficacy of EBD analysis. Overall, this video article provides an outline to perform EBD injection and characterization in zebrafish models of neuromuscular disease.

In this study, we describe a straightforward method to perform Evans Blue Dye (EBD) analysis on zebrafish larvae. This technique is a powerful tool for the characterization of skeletal muscle integrity and delineation of zebrafish models of muscular dystrophy, and is a valuable method for the development of novel therapeutics.

Analisi delle larve Zebrafish muscolo scheletrico Integrità con Blu di Evans Dye

The zebrafish model is an emerging system for the study of neuromuscular disorders.  In the study of neuromuscular diseases, the integrity of the muscle ...

Ricerca

Biologia dello sviluppo

Differentiation of the SH-SY5Y Human Neuroblastoma Cell Line

Having appropriate in vivo and in vitro systems that provide translational models for human disease is an integral aspect of research in neurobiology and the neurosciences. Traditional in vitro experimental models used in neurobiology include primary neuronal cultures from rats and mice, neuroblastoma cell lines including rat B35 and mouse Neuro-2A cells, rat PC12 cells, and short-term slice cultures. While many researchers rely on these models, they lack a human component and observed experimental effects could be exclusive to the respective species and may not occur identically in humans. Additionally, although these cells are neurons, they may have unstable karyotypes, making their use problematic for studies of gene expression and reproducible studies of cell signaling. It is therefore important to develop more consistent models of human neurological disease. 
The following procedure describes an easy-to-follow, reproducible method to obtain homogenous and viable human neuronal cultures, by differentiating the chromosomally stable human neuroblastoma cell line, SH-SY5Y. This method integrates several previously described methods1-4 and is based on sequential removal of serum from media. The timeline includes gradual serum-starvation, with introduction of extracellular matrix proteins and neurotrophic factors. This allows neurons to differentiate, while epithelial cells are selected against, resulting in a homogeneous neuronal culture. Representative results demonstrate the successful differentiation of SH-SY5Y neuroblastoma cells from an initial epithelial-like cell phenotype into a more expansive and branched neuronal phenotype. This protocol offers a reliable way to generate homogeneous populations of neuronal cultures that can be used for subsequent biochemical and molecular analyses, which provides researchers with a more accurate translational model of human infection and disease.

It is critical in neurobiology and neurovirology to have a reliable, replicable in vitro system that serves as a translational model for what occurs in vivo in human neurons. This protocol describes how to culture and differentiate SH-SY5Y human neuroblastoma cells into viable neurons for use in in vitro applications.

La differenziazione del SH-SY5Y neuroblastoma umano linea cellulare

Having appropriate in vivo and in vitro systems that provide translational models for human disease is an integral aspect of research in neurobiology and ...

A Method for Lineage Tracing of Corneal Cells Using Multi-color Fluorescent Reporter Mice

Lineage tracing experiments define the origin, fate and behavior of cells in a specific tissue or organism. This technique has been successfully applied for many decades, revealing seminal findings in developmental biology. More recently, it was adopted by stem cell biologists to identify and track different stem cell populations with minimal experimental intervention. The recent developments in mouse genetics, the availability of a large number of mouse strains, and the advancements in fluorescent microscopy allow the straightforward design of powerful lineage tracing systems for various tissues with basic expertise, using commercially available tools. We have recently taken advantage of this powerful methodology to explore the origin and fate of stem cells at the ocular surface using R26R-Confetti mouse. This model offers a multi-color genetic system, for the expression of 4 fluorescent genes in a random manner. Here we describe the principles of this methodology and provide an adaptable protocol for designing lineage tracing experiments; specifically for the corneal epithelium as well as for other tissues.

In this article we describe the principles for designing and performing a multi-color lineage tracing experiment using R26R-Confetti mice. We provide a specific protocol for tracking corneal epithelial cells which can be modified for other tissues of interest.

Un metodo per Lineage Tracing di cellule corneali Utilizzando multicolori topi reporter fluorescente

Lineage tracing experiments define the origin, fate and behavior of cells in a specific tissue or organism. This technique has been successfully applied ...

Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition

Fibrosis is often involved in the pathogenesis of various chronic progressive diseases such as interstitial pulmonary disease. Pathological hallmark is the formation of fibroblastic foci, which is associated with the disease severity. Mesenchymal cells consisting of the fibroblastic foci are proposed to be derived from several cell sources, including originally resident intrapulmonary fibroblasts and circulating fibrocytes from bone marrow. Recently, mesenchymal cells that underwent epithelial-mesenchymal transition (EMT) have been also supposed to contribute to the pathogenesis of fibrosis. In addition, EMT can be induced by transforming growth factor &#946;, and EMT can be enhanced by pro-inflammatory cytokines like tumor necrosis factor &#945;. The gel contraction assay is an ideal in vitro model for the evaluation of contractility, which is one of the characteristic functions of fibroblasts and contributes to wound repair and fibrosis. Here, the development of a gel contraction assay is demonstrated for evaluating contractile ability of mesenchymal cells that underwent EMT.

Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition

Here, we describe the development and application of a gel contraction assay for evaluating contractile function in mesenchymal cells that underwent epithelial-mesenchymal transition.

Sviluppo di un<em&gt; In Vitro</em&gt; Test per valutare funzione contrattile del mesenchimali Le cellule che sono stati sottoposti a transizione epitelio-mesenchimali

Fibrosis is often involved in the pathogenesis of various chronic progressive diseases such as interstitial pulmonary disease. Pathological hallmark is ...

Conditional Reprogramming of Pediatric Human Esophageal Epithelial Cells for Use in Tissue Engineering and Disease Investigation

Identifying and expanding patient-specific cells in culture for use in tissue engineering and disease investigation can be very challenging. Utilizing various types of stem cells to derive cell types of interest is often costly, time consuming and highly inefficient. Furthermore, undesired cell types must be removed prior to using this cell source, which requires another step in the process. In order to obtain enough esophageal epithelial cells to engineer the lumen of an esophageal construct or to screen therapeutic approaches for treating esophageal disease, native esophageal epithelial cells must be expanded without altering their gene expression or phenotype. Conditional reprogramming of esophageal epithelial tissue offers a promising approach to expanding patient-specific esophageal epithelial cells. Furthermore, these cells do not need to be sorted or purified and will return to a mature epithelial state after removing them from conditional reprogramming culture. This technique has been described in many cancer screening studies and allows for indefinite expansion of these cells over multiple passages. The ability to perform esophageal screening assays would help revolutionize the treatment of pediatric esophageal diseases like eosinophilic esophagitis by identifying the trigger mechanism causing the patient's symptoms. For those patients who suffer from congenital defect, disease or injury of the esophagus, this cell source could be used as a means to seed a synthetic construct for implantation to repair or replace the affected region.

Expansion of human pediatric esophageal epithelial cells utilizing conditional reprogramming provides investigators with a patient-specific population of cells that can be utilized for engineering esophageal constructs for autologous implantation to treat defects or injury and serve as a reservoir for therapeutic screening assays.

La riprogrammazione di cellule condizionale Pediatric umana esofageo epiteliali per l&#39;uso in ingegneria dei tessuti e la malattia Investigation

Identifying and expanding patient-specific cells in culture for use in tissue engineering and disease investigation can be very challenging. Utilizing ...

A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro

The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global DNA methylation level of chondrocytes is considered to be a suitable biomarker for the loss of the chondrocyte phenotype. However, results based on different experimental methods can be inconsistent. Therefore, it is important to establish a precise, simple, and rapid method to quantify global DNA methylation levels during chondrocyte dedifferentiation.
Current genome-wide methylation analysis techniques largely rely on bisulfite genomic sequencing. Due to DNA degradation during bisulfite conversion, these methods typically require a large sample volume. Other methods used to quantify global DNA methylation levels include high-performance liquid chromatography (HPLC). However, HPLC requires complete digestion of genomic DNA. Additionally, the prohibitively high cost of HPLC instruments limits HPLC&#39;s wider application.
In this study, genomic DNA (gDNA) was extracted from human chondrocytes cultured with varying number of passages. The gDNA methylation level was detected using a methylation-specific dot blot assay. In this dot blot approach, a gDNA mixture containing the methylated DNA to be detected was spotted directly onto an N+ membrane as a dot inside a previously drawn circular template pattern. Compared with other gel electrophoresis-based blotting approaches and other complex blotting procedures, the dot blot method saves significant time. In addition, dot blots can detect overall DNA methylation level using a commercially available 5-mC antibody. We found that the DNA methylation level differed between the monolayer subcultures, and therefore could play a key role in chondrocyte dedifferentiation. The 5-mC dot blot is a reliable, simple, and rapid method to detect the general DNA methylation level to evaluate chondrocyte phenotype.

A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro

We present a method to quantify DNA methylation based on the 5-methylcytosine (5-mC) dot blot. We determined the 5-mC levels during chondrocyte dedifferentiation. This simple technique could be used to quickly determine the chondrocyte phenotype in ACI treatment.

Un test a blot di 5 mc quantificando il livello di metilazione del DNA della dedifferentiation di condrociti<em&gt; In vitro</em

The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global ...

In Vitro Growth of Mouse Preantral Follicles Under Simulated Microgravity

14 day-old mouse ovarian tissue and preantral follicles isolated from same-aged mice were incubated in a simulated microgravity culture system. We quantitatively assessed follicle survival, measured follicle and oocyte diameters, and examined ultrastructure of the oocytes produced from the system. We observed decreased follicle survival, downregulation of expressions of proliferating cell nuclear antigen and growth differentiation factor 9, as indicators for the development of granulosa cells and oocytes, respectively, and oocyte ultrastructural abnormalities under the simulated microgravity condition. The simulated microgravity experimental setup needs to be optimized to provide a model for investigation of the mechanisms involved in the oocyte/follicle in vitro development.

In Vitro Growth of Mouse Preantral Follicles Under Simulated Microgravity

A highly promising technique to generate tissue constructs without using matrix is to culture cells in a simulated microgravity condition. Using a rotary culture system, we examined ovarian follicle growth and oocyte maturation in terms of follicle survival, morphology, growth, and oocyte function under the simulated microgravity condition.

In Vitro Crescita dei follicoli preantrali Mouse sotto condizioni di microgravità simulata

14 day-old mouse ovarian tissue and preantral follicles isolated from same-aged mice were incubated in a simulated microgravity culture system. We ...

Live Imaging of Mouse Secondary Palate Fusion

The fusion of the secondary palatal shelves to form the intact secondary palate is a key process in mammalian development and its disruption can lead to cleft secondary palate, a common congenital anomaly in humans. Secondary palate fusion has been extensively studied leading to several proposed cellular mechanisms that may mediate this process. However, these studies have been mostly performed on fixed embryonic tissues at progressive timepoints during development or in fixed explant cultures analyzed at static timepoints. Static analysis is limited for the analysis of dynamic morphogenetic processes such a palate fusion and what types of dynamic cellular behaviors mediate palatal fusion is incompletely understood. Here we describe a protocol for live imaging of ex vivo secondary palate fusion in mouse embryos. To examine cellular behaviors of palate fusion, epithelial-specific Keratin14-cre was used to label palate epithelial cells in ROSA26-mTmGflox reporter embryos. To visualize filamentous actin, Lifeact-mRFPruby reporter mice were used. Live imaging of secondary palate fusion was performed by dissecting recently-adhered secondary palatal shelves of embryonic day (E) 14.5 stage embryos and culturing in agarose-containing media on a glass bottom dish to enable imaging with an inverted confocal microscope. Using this method, we have detected a variety of novel cellular behaviors during secondary palate fusion. An appreciation of how distinct cell behaviors are coordinated in space and time greatly contributes to our understanding of this dynamic morphogenetic process. This protocol can be applied to mutant mouse lines, or cultures treated with pharmacological inhibitors to further advance understanding of how secondary palate fusion is controlled.

Here, we present a protocol for live imaging of mouse secondary palate fusion using confocal microscopy. This protocol can be used in combination with a variety of fluorescent reporter mouse lines, and with pathway inhibitors for mechanistic insight. This protocol can be adapted for live imaging in other developmental systems.

Imaging Live di Mouse Seconda Palate Fusion

The fusion of the secondary palatal shelves to form the intact secondary palate is a key process in mammalian development and its disruption can lead to ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

Dissezione e macchiatura immunofluorescente del corpo di fungo e del fotoricettore neuroni nel cervello adulto Drosophila melanogaster

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands

Notch signaling is an evolutionarily conserved cell-cell communication system used broadly in animal development and adult maintenance. Interaction of the Notch receptor with ligands from neighboring cells induces activation of the signaling pathway (trans-activation), while interaction with ligands from the same cell inhibits signaling (cis-inhibition). Proper balance between trans-activation and cis-inhibition helps establish optimal levels of Notch signaling in some contexts during animal development. Because of the overlapping expression domains of Notch and its ligands in many cell types and the existence of feedback mechanisms, studying the effects of a given post-translational modification on trans- versus cis-interactions of Notch and its ligands in vivo is difficult. Here, we describe a protocol for using Drosophila S2 cells in cell-aggregation assays to assess the effects of knocking down a Notch pathway modifier on the binding of Notch to each ligand in trans and in cis. S2 cells stably or transiently transfected with a Notch-expressing vector are mixed with cells expressing each Notch ligand (S2-Delta or S2-Serrate). Trans-binding between the receptor and ligands results in the formation of heterotypic cell aggregates and is measured in terms of the number of aggregates per mL composed of &#62;6 cells. To examine the inhibitory effect of cis-ligands, S2 cells co-expressing Notch and each ligand are mixed with S2-Delta or S2-Serrate cells and the number of aggregates is quantified as described above. The relative decrease in the number of aggregates due to the presence of cis-ligands provides a measure of cis-ligand-mediated inhibition of trans-binding. These straightforward assays can provide semi-quantitative data on the effects of genetic or pharmacological manipulations on the binding of Notch to its ligands, and can help deciphering the molecular mechanisms underlying the in vivo effects of such manipulations on Notch signaling.

Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands

Complexity of in vivo systems makes it difficult to distinguish between the activation and inhibition of Notch receptor by trans- and cis-ligands, respectively. Here, we present a protocol based on in vitro cell-aggregation assays for qualitative and semi-quantitative evaluation of the binding of Drosophila Notch to trans-ligands vs cis-ligands.

Cella di aggregazione saggi per valutare l'associazione della tacca della drosofila con Trans-ligandi e la sua inibizione di Cis-ligandi

Notch signaling is an evolutionarily conserved cell-cell communication system used broadly in animal development and adult maintenance. Interaction of the ...