Gostaríamos de estender nossos sinceros agradecimentos ao Dr. Ben Fowler para sua ajuda técnica com os experimentos de temperatura.

Este protocolo segue as diretrizes do Conselho de revisão de Universidade de Oklahoma Health Sciences Center/institucional (IRB #4509). Todas as partes do protocolo de conheceram os princípios da declaração de Helsinki. Corneais amostras foram obtidas de desenvolvimento nacional e Instituto de pesquisa (NDRI) e o banco de olhos do Lions de Oklahoma.
1. isolamento de células primárias
<ol><li>Após a recepção de amostras de tecido da córnea humana, transferir os tecidos em um 21,5 cm2 placa de Petri contendo 2 mL de fosfato salino de estéril Dulbecco (DPBS) (1x).</li>
	<li>Raspar e remover o epitélio corneano posicionando a córnea cúpula viradas para cima. Para garantir a remoção completa, raspar a camada epitelial cuidadosamente, usando uma lâmina de barbear em um ângulo de 45°. Em seguida, virar a córnea cúpula virada para baixo e completamente raspar o endotélio do estroma com uma lâmina de barbear em um ângulo de 45° para assegurar a completa remoção. Lave o tecido estromal com DPBS.</li>
	<li>Corte os tecidos stromal em pedaços pequenos, usando uma lâmina cirúrgica n º 10, mantendo as peças do estroma molhadas em todo tempo usando DPBS. Pegar peças do estroma com pinça estéril e coloque em um frasco de cultura T25 sem mídia (4 ou 5 pedaços de tecido de 2 x 2 mm por balão).</li>
	<li>Permitir que os explantes aderir ao fundo do balão a 37 ° C por cerca de 30-40 min. Uma vez aderido, lentamente adicione mínimo essencial meio do águia (EMEM) contendo 10% de soro fetal bovino (FBS) e 1% antibiótico/Antimycotic no balão sem perturbar os explantes.</li>
	<li>Delicadamente, coloque o frasco na incubadora a 37 ° C, 5% de CO2. Deixe os explantes imperturbado até as células começam a isolar e a migração do balão. Após aproximadamente 2-4 semanas, as células devem alcançar confluência de 100%. Após a confluência de 100%, passagem as células, removendo os meios de cultura de tecido e lave as células com DPBS.</li>
	<li>Adicionar tripsina para as células e então eles incubar a 37° C. Após cerca de 5 min, ver as células sob microscopia de luz, para confirmar que eles têm destacado e depois parará a proteólise adicionando mídia fresca.</li>
	<li>Transferir a suspensão de células para um tubo cônico de 15 mL por centrifugação a x 1.000 g. remover o sobrenadante cuidadosamente sem perturbar o sedimento e suspender as células no EMEM fresco 10% FBS 1% antibiótico. Contar as células e propagar a cerca de 1 x 106 células no frasco de cultura T75 para expansão ainda mais com EMEM fresco 1% FBS 1% antibiótico.</li>
</ol>2. primário HCFs cultura e montagem de construções 3D
<ol><li>Para montar 3D construções do explants EMEM anteriormente cultivado em 10% FBS 1% antibiótico/Antimycotic, passagem e contagem HCFs.</li>
	<li>10% de sementes aproximadamente 1 x 106 células/poço de HCFs primários em policarbonato inserções de membrana com poros de 0,4 µm das construções 3D, juntamente com 1,5 mL de fresco EMEM FBS 1% antibiótico/Antimycotic para o topo da construção. Adicione outro 1,5 mL do mesmo meio para o fundo de cada construção.</li>
	<li>Após 24h de célula semeadura, cultura de células com EMEM 10% FBS 1% antibiótico/Antimycotic, estimulados com o ácido 2-O-α-D-glucopyranosyl-L-ascorbic (vitamina C) de 0,5 mM por adicionar 1,5 mL no topo e 1,5 mL na parte inferior de cada construção.</li>
	<li>Manter as culturas em uma incubadora a 37 ° C, 5% de CO2 por 3 semanas e fornecer mídia fresca todos os dias durante o período de estudo inteiro. Nenhuma passagem adicional é necessária.</li>
</ol>3. diferenciação e co culturas de pilha
<ol><li>Após 3 semanas, adicionar 8 x 103 células/poço de células de neuroblastoma humano SH-SY5Y no topo o 3D previamente montado constrói com 1,5 mL do EMEM contendo 10% FBS, 2-O-α-D-glucopyranosyl-L-ascorbic 1% antibiótico/Antimycotic e 0,5 mM ácido (vitamina C).<ol>
<li>Permitir que as células de neuroblastoma de SH-SY5Y de crescer em cima de células do estroma da córnea pelo menos 24 h antes de iniciar a diferenciação celular.</li>
	</ol>
</li>
	<li>Iniciar a diferenciação de células SH-SY5Y, estimulando as células com EMEM contendo 1% FBS e 1,5 mL de 10 µM ácido retinoico no topo da construção. Adicione 1,5 mL do EMEM 10% FBS 1% antibiótico/Antimycotic 0.5 mM 2-O-α-D-glucopyranosyl-L-ascorbic ácido (vitamina C) para o fundo de construção. Observe que o passo ácido retinoico deve ser realizado no escuro.<ol>
<li>Continue a cultura de células na mídia diferenciação por 5 dias.</li>
	</ol>
</li>
	<li>Quando as células atingem a fase de diferenciação, alternar as células a 1,5 mL de soro livre mídia contendo 2 nM de fator neurotrófico derivado do cérebro (BDNF) e 1% antibiótico/Antimycotic adicionado para o EMEM, adicionando ao topo da construção. Adicione 1,5 mL do EMEM 10% FBS 1% antibiótico/Antimycotic 0.5 mM 2-O-α-D-glucopyranosyl-L-ascorbic ácido (vitamina C) para o fundo de construção. Observe que a etapa BDNF deve ser realizada no escuro.</li>
	<li>Cultura de células para 2 dias adicionais antes do processamento para qualquer análise mais aprofundada como indicado na tabela 1.</li>
</ol>

<ol>
	<li>Pascolini, D., Mariotti, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+estimates+of+visual+impairment:+2010.">Global estimates of visual impairment: 2010.</a> Br J Ophthalmol. 96 (5), 614-618 (2012).</li><li>R&#246;nkk&#246;, S., Vellonen, K. -. S., J&#228;rvinen, K., Toropainen, E., Urtti, A. <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+cell+culture+models+for+drug+toxicity+studies.">Human corneal cell culture models for drug toxicity studies.</a> Drug Delivery and Translational Research. 6 (6), 660-675 (2016).</li><li>Ghezzi, C. E., Rnjak-Kovacina, J., 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=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. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aqueous+tear+production+in+patients+with+neurotrophic+keratitis.">Aqueous tear production in patients with neurotrophic keratitis.</a> Cornea. 15 (2), 135-138 (1996).</li><li>Wang, 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=In+vitro+3D+corneal+tissue+model+with+epithelium,+stroma,+and+innervation.">In vitro 3D corneal tissue model with epithelium, stroma, and innervation.</a> Biomaterials. 112, 1-9 (2017).</li><li>Ross, R. A., Spengler, B. A., Biedler, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coordinate+morphological+and+biochemical+interconversion+of+human+neuroblastoma+cells.">Coordinate morphological and biochemical interconversion of human neuroblastoma cells.</a> J Natl Cancer Inst. 71 (4), 741-747 (1983).</li><li>Griffith, L. G., Naughton, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+engineering+-+Current+challenges+and+expanding+opportunities.">Tissue engineering - Current challenges and expanding opportunities.</a> Science. 295 (5557), (2002).</li><li>Guo, X., 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=Morphologic+characterization+of+organized+extracellular+matrix+deposition+by+ascorbic+acid-stimulated+human+corneal+fibroblasts.">Morphologic characterization of organized extracellular matrix deposition by ascorbic acid-stimulated human corneal fibroblasts.</a> Invest Ophthalmol Vis Sci. 48 (9), 4050-4060 (2007).</li><li>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=Ocular+tissue+engineering:+current+and+future+directions.">Ocular tissue engineering: current and future directions.</a> J Funct Biomater. 6 (1), 77-80 (2015).</li><li>Karamichos, D., Brown, R. 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. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+experimental+model+for+assessing+fibroblast+migration+in+3-D+collagen+matrices.">An experimental model for assessing fibroblast migration in 3-D collagen matrices.</a> Cell Motil Cytoskeleton. 66 (1), 1-9 (2009).</li><li>Karamichos, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+in+Vitro+Model+for+Keratoconus+Disease.">Novel in Vitro Model for Keratoconus Disease.</a> J Funct Biomater. 3 (4), 760-775 (2012).</li></ol>

Os autores declaram não concorrentes interesses financeiros.

Vários estudos têm sido focados no desenvolvimento de vários modelos de animais que podem ajudar a desenvolver uma melhor compreensão de doenças da córnea, bem como descobrir tratamentos. No entanto, um valor significativo para os seres humanos destes estudos não foi verificado. Até à data, vários em vitro modelos foram desenvolvidos e amplamente investigadas devido a sua notável importância clínica. Nosso modelo estabelecido anteriormente 3D em vitro é um sistema inovador que significativ...

No corpo humano, a córnea é o tecido mais densamente inervado. Os nervos são responsáveis por várias sensações como o toque, dor, temperatura e também têm um papel essencial na cicatrização de feridas, piscar reflexos, rasgar a produção e secreção de5,6,7. Na córnea, estromais troncos nervosos surgem do plexo limbal e insira o estroma da córnea periférico radialmente. A organização do nervo do estroma é paralela as lamelas de colágeno e eles ainda mais ramificam em fascículos menores como proceder para o estroma superficial5,8. As fibras nervosas mais penetrar a camada epitelial e assim, inervação é amplamente espalhada por todo o epitélio corneano e o estroma. Portanto, a inervação tem um papel essencial no estado saudável e doente da córnea. Neste protocolo, revelamos o avanço de um modelo novela 3D em vitro , que é a primeira de seu tipo para imitar as interações do estroma-nervo na vivo . A linha de celular de SH-SY5Y foi utilizada para este estudo, como é uma das linhas mais estabelecidas, bem caracterizadas usadas para estudar o crescimento neuronal. A linha de celular de SH-SY5Y tem sido descrita para produzir ambos os aderentes do substrato (tipo S) e neuroblastic (N-tipo) de células que podem sofrer transdiferenciação celular9. Como resultado, mesmo que esta linha de celular é derivada de uma seleção de triplo subclone sucessivas de células de tipo N, ele também contém um pequeno número de células do tipo S capazes de sofrer diferenciação em neurônios através do uso de retinoico ácido e derivado do cérebro Neurotrophic factor9. Isso fornece uma ferramenta que pode levar a uma melhor compreensão das complicações da córnea associado com retinopatia diabética (DM) e outras doenças oculares. Devido as dificuldades associadas com a obtenção e cultivo de neurônios de pacientes com doença ocular, este modelo 3D em vitro fornece implicações substanciais em estudar as interações neuronais e sinalizando com o estroma corneano.
Condições de doentes frequentemente afetam vários tecidos do corpo a uma escala muito grande, levando a uma qualidade de vida comprometida. Distrofias oculares são complicações comuns, frequentemente associadas com doenças sistêmicas e levam à perda de acuidade visual ou perda de visão até mesmo permanente. Estudos exaustivos muitas vezes são essenciais para uma melhor compreensão da condição da doença, bem como os efeitos a nível celular basal. Para estudar os efeitos de tais doenças, foram desenvolvidos vários modelos in vivo e in vitro com a ajuda de aplicações de engenharia de tecidos. Aplicações da engenharia do tecido corneal tem atraído grande interesse através dos vários campos da ciência10,11,12,13,14, mas existem ainda grandes limitações durante aplicação real, incluindo corneal enxerto rejeições, infecções e cicatrizes10,11,12,13,14. Existem vários estudos que desenvolveram com sucesso e estabeleceu várias em vitro modelos3,15,16,17,18, 19,20,21,22,23,24,25,26. Os modelos 3D em vitro são os mais promissores e de grande interesse científico. Modelos 3D são conhecidos para melhor espelhar na vivo celular e fisiológico eventos que são essenciais durante a fibrose e o ferimento de28,de27,de15,cura29. Estes modelos em vitro desempenham um papel integral na busca de novas abordagens terapêuticas para o tratamento de condições diferentes da doença, incluindo complicações da córnea. Apesar do papel crítico da inervação em funções da córnea, fez pouco esforço para promover a proliferação de nervo periférico dentro de construções de engenharia de tecido corneal2,3. No entanto, as construções propostas 3D em vitro celular imitam o tecido-alvo para atingir a funcionalidade do tecido desejado.
Enquanto keratopathy diabética é uma aplicação óbvia para o modelo aqui descrito por defeito neuronal, existem várias outras doenças da córnea que podem se beneficiar de um modelo humano em vitro incluindo distrofias ceratocone e Fuchs. Nosso modelo 3D emerge esta perspectiva e propõe o desenvolvimento de uma representação em vitro do tecido da córnea para avaliar a administração de medicamentos e segurança de novos medicamentos oculares.

<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

Engenharia de tecidos ganhou reconhecimento substancial devido à alta demanda para as substituições de córnea humana com cerca 10 milhões de pessoas no mundo sofrem de perda de visão da córnea1. Para atender a demanda de córneas humanas viáveis, progressos significativos em tecido tridimensional (3D) engenharia foi feita2,3,4. Estes córnea modelos variam de sistemas monocamada simples até modelos de várias camados, levando a 3D cheio-espessura corneal equivalentes2.
No entanto, o uso de uma córnea 3D engenharia de tecidos, no contexto dos modelos de doença em vitro estudou a semelhança de falta de data para a estrutura de várias camadas de tecido corneal 3D, função e a interconexão dos diferentes tipos de células (ou seja, nervo, epitélio, estroma e endotélio)2,3. Além disso, a procura de modelos de tecido em vitro córnea tem aumentado na tentativa de reduzir a testes em animais para produtos farmacêuticos. Assim, modelos mais sofisticados são necessários para melhor coincidir com sistemas às exigências fisiológicas humanas e o desenvolvimento de um modelo que é mais relevante para a população de pacientes seja absolutamente necessário. Dado que vários tipos de células na córnea são afetados por doenças e distrofias, tais como ceratocone, ceratopatia diabética e Fuchs, este modelo inclui um modelo 3D co-cultura de fibroblastos da córnea humanos primários (HCFs) de doadores saudáveis e os neurônios de a linha de celular de SH-SY5Y. Isto permite-pela primeira vez investigar as interações entre os tipos de dois célula dentro do tecido da córnea humano. Acreditamos que este modelo poderia potencialmente dissecar os mecanismos subjacentes associados com as interações de nervo do estroma corneal doenças que apresentam danos do nervo. Este modelo 3D espelha a natureza básica de anatômica e fisiológica do tecido corneal na vivo e pode ser usado no futuro como uma ferramenta para investigar defeitos da córnea, bem como a eficácia dos vários agentes de triagem antes de testes em animais.

A Figura 1 é uma passo a passo imagem representativa do modelo de trabalho 3D em vitro . Na primeira etapa, as células são isoladas da córnea humana. Em seguida, são cultivadas em uma membrana de policarbonato e estimuladas com vitamina C para montar uma matriz 3D auto secretado. Este sistema de construção 3D induz a síntese de um várias camadas celulares na vivo-como matriz do estroma. Posteriormente, as células de neuroblastoma s...

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

Este protocolo descreve um romance tridimensional em vitro modelo, onde as células do estroma corneana e diferenciada de células neuronais são cultivadas juntos para ajudar na análise e compreensão das interações dos tipos de célula de dois.

Engenharia de tecido corneal: Um em Vitro modelo das interações nervo-estromal da córnea humana

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

Research

JoVE Journal

Developmental Biology

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

8.7K visualizações.  University of Oklahoma Health Sciences Center. Este protocolo descreve um romance tridimensional em vitro modelo, onde as células do estroma corneana e diferenciada de células neuronais são cultivadas juntos para ajudar na análise e compreensão das interações dos tipos de célula de dois.

Vídeo: 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.

Análise de Zebrafish larvas Músculo Esquelético Integrity com 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 ...

Biologia do Desenvolvimento

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.

A diferenciação da linha celular SH-SY5Y humanas de neuroblastoma

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.

Um método para Lineage Tracing de células da córnea Usando Multi-cor repórter fluorescente Mice

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.

Desenvolvimento de um<em&gt; In Vitro</em&gt; Ensaio para avaliar contrátil Função de células mesenquimais que a transição epitelial-mesenquimal Sofreu

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.

Reprogramação condicional de células Pediátrica Humano esofágico epiteliais para uso em Engenharia de Tecidos e Doença de Investigação

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.

Um Ensaio de Blot de Ponto de 5 mC Quantificando o Nï¿½el de Metilaï¿½o de ADN da Dediferenciaï¿½o de Condrocitos<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 Crescimento do folículo pré-antral do Mouse sob microgravidade simulado

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.

Imagem ao vivo do mouse Fusão do palato secundário

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.

Dissecção e imunofluorescência coloração de cogumelo corpo e fotoreceptor neurônios em cérebros adultos 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.

Celular agregação ensaios para avaliar a vinculação do entalhe drosófila com Trans-ligantes e sua inibição pelo Cis-ligantes

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