The authors would like to thank Mark Bishop, Mathew Zverev, Victoria Marsh-Durban, Adam Blackwood and Sylvie Robine. This work was funded by a programme grant from Cancer Research UK.

<ol>
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The authors have nothing to disclose.

Usando camundongos transgênicos cre-lox condicionais para dissecar a função dos genes e células é um método comumente usado. Estes modelos têm sido utilizados com grande sucesso no intestino para identificar e caracterizar as células-tronco 2,4-6 e compreender o seu papel na doença 25. Para explorar plenamente destes modelos requer uma caracterização global do sistema para permitir que os dados sejam interpretados corretamente. Uma compreensão completa destes sistemas é difícil de realizar devido a genes raramente ser específico para um tipo celular ou localização solitária, uma falta de conhecimento biológico e ineficiência dos sistemas utilizados para induzir a expressão de Cre. Os métodos descritos aqui demonstrar como podemos superar esses problemas através de planejamento experimental e aplicação do conhecimento existente. Embora tenhamos usado esses métodos para responder a uma pergunta de investigação específico das técnicas apresentadas aqui são genéricas e podem ser explorado para qualquer pesquisa que investiga o muriintestino ne. Preparação de tecido intestinal O passo fundamental para garantir resultados robustos é a colheita e processamento do tecido, o que precisa ser processado de uma maneira oportuna e de fixação protocolos rigorosamente respeitados. Como quase todos os problemas significativos a jusante podem ser atribuídas a artefactos associados com a secagem do tecido para fora e / ou fixação incompleta. O tempo é essencial para evitar a degradação da arquitectura do tecido e / ou os ácidos nucleicos e proteínas. Fixação incompleta ou exagerada pode resultar em perda de resolução histoquímica. Fixação incompleta por falta de tempo ou seções muito grossas para permitir a penetração fixador pode resultar em perda de resolução dentro das criptas intestinais que podem ser observados como uma &quot;marca da maré&quot; na análise IHC. Além disso, é fundamental que a fixação não se estenda por muito tempo, como nuclear β-catenina pode difundir para fora do núcleo, a menos que imediatamente pronão transformados e cera incorporado seguinte fixação em formalina. Papel de Paneth Células no nicho ISC Os dados aqui apresentados demonstram de forma eficaz a importância das células de Paneth na regeneração cripta no intestino adulto após perda ISC. No entanto, há a possibilidade de que permaneceu Ah-cre poupa uma população de ISC que as metas T2 vil-Cre-ER. 26 Tian et al. Elegantemente demonstrou que as ISC hi Lgr5 são substituídos por uma população de Lgr5 lo ISC reserva. Agora parece provável que estes ISC são poupadas no sistema cre-Ah devido à população de reserva tenham sido identificados como precursores de células secretoras 6,7. A importância da célula de Paneth maduro no apoio a estes precursores de células secretoras quando necessário para reverter a um estado ISC continua a ser respondida. Como as células de Paneth constituem o ISC nicho 8 e desempenham um papel na regulação das respostas do ISC a ingestão de calorias 27 e 28 de inflamação permanece provável que as suas funções de enfermagem se estenderá para os seus próprios precursores. Novas abordagens e tecnologias para efetivamente Modelo Câncer Colorretal Humano A descoberta do ISC levou à identificação de genes que estão agora a ser utilizados para gerar novos modelos de ratos para investigar os papéis de genes e células em biologia intestinal e doença, revisado por Clarke et al 9. As únicas limitações para esta técnica é a identificação de genes para expressar a proteína Cre. Actualmente ISC são rotineiramente investigada utilizando ratinhos transgénicos condicionais baseados no padrão de expressão do gene Lgr5. Os ratinhos que expressam Cre a partir do promotor Lgr5 foram utilizados para excluir APC, o gene mais comummente mutado no cancro colo-rectal (CRC), Demonstrando a ISC como a célula de origem 25. Seletivamente apagar outros genes nessas células CRC está fornecendo informações sobre a progressão da doença e se espalhou por exemplo. PTEN 29. Uma visão mais aprofundada função ISC está sendo recuperado por especificamente ablação Lgr5 -expressing células em camundongos usando um receptor de toxina da difteria humana (DTR) gene bateu na Lgr5 lócus 26. Outras estratégias usar o sistema Tet-O que permite a expressão reversíveis em curso de proteínas mutantes 30. O uso dessas ferramentas para modificar gene (s) em diferentes células 31 e locais 32,33 é usado para entender como câncer de iniciar, o progresso ea metástase 34. Alternativamente mutagénese utilizando o sistema de beleza transposon dormir é identificar novos drivers de CRC. O desenvolvimento contínuo de ratinhos, técnicas e estratégias de alteração genética continua a desenvolver modelos mais relevantes do paciente. New métodos têm sido desenvolvidos para a caracterização dos epitélios intestinais e ISC. Caracterização do rácio de tipos de células epiteliais podem ser alcançados utilizando citometria de fluxo com base na expressão diferencial de lectina e de CD24 35. Potencialmente o maior progresso na compreensão da biologia ISC eo seu papel na doença será feita utilizando o sistema vivo organï¿½de ex cultura 36. Este sistema permite ISC normais e malignas à cultura em 3D, onde eles diferenciam e replicar de um modo mais fisiologicamente relevante. Espera-se que estes irão permitir o teste direto de drogas em amostras de pacientes in vitro, abrindo o caminho para a medicina personalizada 37.

A superfície luminal do intestino de mamífero apresenta unidades de criptas e repetindo dedo como projecções, denominado vilosidades, que se projectam para dentro do lúmen. Esta superfície é uma folha contínua do epitélio, que é submetido a auto-renovação completa aproximadamente a cada 3 - 4 dias 1. Este tecido dinâmico é suportado por uma população de células estaminais rapidamente bicicleta (ISC, também conhecido como base de cripta células colunares), que foram inicialmente identificadas pela sua expressão do gene Lgr5 2,3. Estas células existir num nicho especializado na parte inferior das criptas de Lieberkuhn. Inicialmente, a descoberta de que ISC foram ciclismo rapidamente foi discordante com a idéia predominante de que uma célula-tronco foi de repouso na natureza. Anterior à identificação do Lgr5 + ISC foi postulado que uma população de células quiescentes etiqueta na posição 4, em relação à base da cripta de retenção, foram a ISC 1. Recentes pesquisas hcomo agora reconciliou essas observações, demonstrando que principalmente há uma piscina de ciclismo equipotent ISC em cada cripta cujo destino são regulados por seus vizinhos 4,5. No caso de serem perdidos estes podem ser substituídos por células quiescentes que normalmente são comprometidos com a linhagem secretora, mas pode reverter a ISC se a população ISC está danificado 6. Vizinhos ISC pode ser ISC ou suas células filhas. As ISC produzir células filhas virgens de tratamento que se multiplicam e se diferenciam em tipos de células especializadas que compõem a folha epitelial que reveste o lúmen intestinal 1. O cálice, enteroendï¿½rina, enterócitos, topete e células M migrar para cima, para a superfície luminal onde eles fornecem várias funções de absorção e de regulamentação, no entanto, as células de Paneth permanecem no fundo da cripta onde eles existem misturados com o ISC. Nos últimos anos, tem sido demonstrado que uma parte do daught naïveer células destinados a uma linhagem secretora são etiqueta de repouso reter células Lgr5 lo capaz de reverter a uma ISC sobre lesão 6,7. Devido a sua importância na regeneração cripta uma prioridade foi colocado na compreensão das interações entre a ISC e os seus vizinhos, particularmente as células de Paneth. As células de Paneth desempenham um papel crucial no nicho que apoia a ISC 8. Em adição aos produtos bactericidas as células de Paneth produzir moléculas de sinalização que activam as vias que regulam ISC renovação ou diferenciação. Estudos anteriores mostraram que o Lgr5 + ISC só poderia existir quando eles poderiam competir para sinais de nicho essenciais prestados por sua filha células Paneth 8. Estes estudos investigaram o papel de células de Paneth em Lgr5 + normais ISC e não numa situação em que eles são danificado e necessitar reabastecimento a partir de uma população Lgr5 Lo. <pclass = &quot;jove_content&quot;&gt; Para entender a biologia e modelo de doença intestinal que examinar o papel funcional das células e / ou genes utilizando modelos de ratos transgênicos 9,10. Freqüentemente, esses modelos utilizam tecnologia cre-lox para modificar condicionalmente gene (s) 9,10. Cre (Causas recombinação) recombinase é uma recombinase específica do local da família integrase, isolado do bacteriófago P1. Cre catalisa recombinação sítio específica definida entre 34 pb &#39; Lox P &#39;(lócus χ de cruzamento P1) sites. Os ratinhos são geneticamente manipuladas para conter sítios loxP que flanqueiam regiões de interesse que após a expressão da recombinase Cre são excisadas. Ligando a expressão do gene Cre para uma célula ou um promotor específico do desenvolvimento permite a alteração a ser feita de uma forma espacial 9,10, isto é especialmente útil em superar as mutações letais embrionárias. Além disso ligando a expressão de Cre para uma via do receptor,que pode ser activada artificialmente, permite alterações temporais. Utilizando esta tecnologia, o gene inactivado CatnB 11 nos epitélios intestinais. β-catenina, o produto do gene CatnB, é um regulador chave da via de sinalização Wnt canónica que regula a homeostase do ISC. Dois estudos anteriores usando essa estratégia produziu resultados conflitantes 12,13. O estudo de FEVR et al. 12, demonstraram perda de células-tronco e homeostase intestinal. Considerando que o Ireland et al. 14 estudo relatou que a sequência de uma redução na viabilidade das células da cripta-vilosidade eixo foi repovoada a partir de células de tipo selvagem que expressam CatnB. A diferença principal nestes estudos era o promotor utilizado para expressar CRE na epitélios intestinais. O FEVR et ai., Foi utilizado o promotor do gene de vilina ligado ao receptor de estrogénio, que pode ser activado através da administração de tamoxifen (vil-Cre-ER T2) 15,16. Em contraste Ireland et al., Utilizou-se o elemento promotor do gene da citocromo rato P450A1 (CYP1A1) para conduzir a expressão de Cre em resposta ao β-naftoflavona xenobióticos (Ah-CRE). As características destes diferentes sistemas gerado duas hipóteses para explicar essas observações diferentes. A primeira é que CatnB mais eficientemente eliminado na ISC usando o sistema Cre-T2 Vil-ER em comparação com o AH-CRE, reduzindo assim o número de ISCs para níveis sub-repovoamento. Alternativamente, foi devido ao diferencial CatnB deleção na população de células diferenciadas. Os vil-Cre-ER alvos de sistemas T2 todas as células epiteliais da cripta e das vilosidades Considerando que o sistema Ah-cre tem como alvo apenas as células não Paneth do nicho ISC e cripta. Estes sistemas, desde ferramentas ideais para examinar o behavior do ISC e sua interação com as células de Paneth. Aqui nós apresentamos vários protocolos detalhados com base em como usamos estes sistemas para determinar que as células de Paneth desempenham um papel crucial na mediação da resposta intestinal à injúria 17.

<table border="0" cellpadding="0" cellspacing="0">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr>
			<td>Acetate buffer</td>
			<td>*</td>
			<td>*</td>
			<td>To make 100ml: 4.8ml 0.2M Acetic acid, 45.2ml 0.2M Sodium acetate &#38; 50ml distilled water</td>
		</tr>
		<tr>
			<td>Acetic acid</td>
			<td>Fisher Scientific</td>
			<td>C/0400/PB17</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic anhydride</td>
			<td>Sigma</td>
			<td>A6404</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic anhydride solution</td>
			<td>*</td>
			<td>*</td>
			<td>2 M Acetic anhydride in 0.1 M triethanolamine hydrochloride</td>
		</tr>
		<tr>
			<td>Alcian Blue</td>
			<td>Sigma</td>
			<td>A5268</td>
			<td></td>
		</tr>
		<tr>
			<td>Alcian Blue ph2.5</td>
			<td>*</td>
			<td>*</td>
			<td>To make 500ml: 15ml acetic acid, 5g Alcian Blue &#38; 485ml distilled water</td>
		</tr>
		<tr>
			<td>anti-digoxigenin alkaline phosphatase conjugated antibody</td>
			<td>Abcam</td>
			<td>ab119345</td>
			<td></td>
		</tr>
		<tr>
			<td>B(beta)-Naphthoflavone</td>
			<td>Sigma</td>
			<td>N3633</td>
			<td>BNF, inject without allowing the solution to cool too much as compound will drop out of solution. Solution can be re-used &#8211; store at -20&#176;C between uses, do not reheat more than twice.</td>
		</tr>
		<tr>
			<td>Bloxall</td>
			<td>Vector Labs</td>
			<td>SP-6000</td>
			<td></td>
		</tr>
		<tr>
			<td>BM purple</td>
			<td>Roche</td>
			<td>11442074001</td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>Sigma</td>
			<td>A4503</td>
			<td>Bovine serum albumin</td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>Fisher Scientific</td>
			<td>C/4920/17</td>
			<td></td>
		</tr>
		<tr>
			<td>Citrate Buffer/Antigen Unmasking Solution</td>
			<td>Vector Labs</td>
			<td>H-3300</td>
			<td></td>
		</tr>
		<tr>
			<td>Corn oil</td>
			<td>Sigma</td>
			<td>C8627</td>
			<td></td>
		</tr>
		<tr>
			<td>Demucifiying solution</td>
			<td>*</td>
			<td>*</td>
			<td>For 500ml: 50ml glycerol, 50ml Tris 0.1M pH8.8, 100ml EtOH, 300ml saline (0.9% NaCl in water), DTT 1.7g.&#160; Demucifying solution can be made in advance and stored, but DTT sholud be added just before incubation (340mg/100ml).</td>
		</tr>
		<tr>
			<td>DEPC treated water</td>
			<td>Life Technologies</td>
			<td>750023</td>
			<td></td>
		</tr>
		<tr>
			<td>DTT</td>
			<td>Sigma</td>
			<td>101509944</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sigma</td>
			<td>O3690</td>
			<td>0.5M</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Fisher Scientific</td>
			<td>E/0650DF/17</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter paper</td>
			<td>Whatman</td>
			<td>3000917</td>
			<td></td>
		</tr>
		<tr>
			<td>Formaldehyde</td>
			<td>Sigma</td>
			<td>F8775</td>
			<td></td>
		</tr>
		<tr>
			<td>Formalin&#160;</td>
			<td>Sigma</td>
			<td>SLBL11382V</td>
			<td>Neutral buffered formalin</td>
		</tr>
		<tr>
			<td>Formamide</td>
			<td>Sigma</td>
			<td>F5786</td>
			<td></td>
		</tr>
		<tr>
			<td>Glutaraldehye</td>
			<td>Sigma</td>
			<td>G6257</td>
			<td></td>
		</tr>
		<tr>
			<td>H2O2</td>
			<td>Sigma</td>
			<td>216763</td>
			<td></td>
		</tr>
		<tr>
			<td>Haematoxylin</td>
			<td>Raymond A Lamb</td>
			<td>12698616</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Gibco</td>
			<td>14175-053</td>
			<td>HBSS (-MgCl2+; -CaCl2)</td>
		</tr>
		<tr>
			<td>Hybridisation buffer</td>
			<td>*</td>
			<td>*</td>
			<td>&#160;5&#215; SSC, 50% formamide, 5% SDS, 1 mg/ml heparin, 1 mg/ml calf liver tRNA</td>
		</tr>
		<tr>
			<td>Hydroquinone</td>
			<td>Sigma</td>
			<td>H9003</td>
			<td></td>
		</tr>
		<tr>
			<td>ImmPACT DAB Peroxidase</td>
			<td>Vector Labs</td>
			<td>SK-4105</td>
			<td></td>
		</tr>
		<tr>
			<td>Immpress HRP Anti-Mouse IgG Kit</td>
			<td>Vector Labs</td>
			<td>MP-7402</td>
			<td></td>
		</tr>
		<tr>
			<td>Immpress HRP Anti-Rabbit IgG Kit</td>
			<td>Vector Labs</td>
			<td>MP-7401</td>
			<td></td>
		</tr>
		<tr>
			<td>Intestinal tissue powder</td>
			<td>*</td>
			<td>*</td>
			<td>The small intestines of 5 adult mice were combined and homogenised in the minimum volume of ice cold PBS. 4 volumes of ice cold acetone were added to the homogenised intestine, which was mixed thoroughly and incubated on ice for 30 minutes. This was centrifuged and the pellet was washed using ice cold acetone. This was further centrifuged and the resulting pellet spread onto filter paper and allowed to dry. Once thoroughly dry the material was ground to a fine powder using a pestle and mortar.&#160;</td>
		</tr>
		<tr>
			<td>K-ferricyanide</td>
			<td>Sigma</td>
			<td>P-3667</td>
			<td></td>
		</tr>
		<tr>
			<td>K-ferrocyanide</td>
			<td>Sigma</td>
			<td>P3289</td>
			<td></td>
		</tr>
		<tr>
			<td>Levamisole</td>
			<td>Sigma</td>
			<td>L0380000</td>
			<td></td>
		</tr>
		<tr>
			<td>Methacarn</td>
			<td>*</td>
			<td>*</td>
			<td>60% Methanol:30% Chloroform:10% Acetic acid</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Fisher Scientific</td>
			<td>M/4000/17</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl2</td>
			<td>Sigma</td>
			<td>M8266</td>
			<td></td>
		</tr>
		<tr>
			<td>Normal goat serum</td>
			<td>Vector Labs</td>
			<td>S-1012</td>
			<td>NGS</td>
		</tr>
		<tr>
			<td>Normal rabbit serum</td>
			<td>Dako</td>
			<td>X0902</td>
			<td>NRS</td>
		</tr>
		<tr>
			<td>NTMT</td>
			<td>*</td>
			<td>*</td>
			<td>100 mM NaCl, 100 mM Tris HCl, 50 mM MgCl2, 0.1% Tween20, 2 mM Levamisole</td>
		</tr>
		<tr>
			<td>PAP pen</td>
			<td>Vector</td>
			<td>H-400</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr>
			<td>PBT</td>
			<td>*</td>
			<td>*</td>
			<td>0.5M NaCl, 10mM TrisHCL pH7.5, 0.1% Tween 20</td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td>100x solutiuon.</td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (10x)</td>
			<td>Fisher Scientific</td>
			<td>BP3994</td>
			<td>Dilluted 1:10 with distilled water to make 1x</td>
		</tr>
		<tr>
			<td>PLL slides</td>
			<td>Sigma</td>
			<td>P0425-72EA</td>
			<td>Poly-L-lysine microscope slides</td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>Sigma</td>
			<td>P2308</td>
			<td></td>
		</tr>
		<tr>
			<td>Proteinase k solution</td>
			<td>*</td>
			<td>*</td>
			<td>Dilute Proteinase K at 200 &#181;g/ml in 50 mM Tris, 5 mM EDTA.</td>
		</tr>
		<tr>
			<td>Ralwax</td>
			<td>BDH</td>
			<td>36154 7N</td>
			<td></td>
		</tr>
		<tr>
			<td>Reducer Solution</td>
			<td>*</td>
			<td>*</td>
			<td>To make 100ml: 1g Hydroquinone, 5g sodium sulphite &#38; 100ml distilled water</td>
		</tr>
		<tr>
			<td>RnaseA</td>
			<td>Sigma</td>
			<td>R6148</td>
			<td></td>
		</tr>
		<tr>
			<td>Saline</td>
			<td>*</td>
			<td>*</td>
			<td>0.9% NaCl in distilled water</td>
		</tr>
		<tr>
			<td>SDS</td>
			<td>Sigma</td>
			<td>I3771</td>
			<td></td>
		</tr>
		<tr>
			<td>Sheep serum</td>
			<td>Sigma</td>
			<td>S3772</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver nitrate</td>
			<td>Sigma</td>
			<td>S/1240/46</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver solution</td>
			<td>*</td>
			<td>*</td>
			<td>To make 100ml: 10ml Acetate buffer, 87ml distilled water, 3ml 1% silver nitrate</td>
		</tr>
		<tr>
			<td>Sodium acetate</td>
			<td>Fisher Scientific</td>
			<td>S/2120/53</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Sigma</td>
			<td>S6753</td>
			<td>NaCl</td>
		</tr>
		<tr>
			<td>Sodium sulfite</td>
			<td>Sigma</td>
			<td>239321</td>
			<td></td>
		</tr>
		<tr>
			<td>SSC</td>
			<td>Sigma</td>
			<td>93017</td>
			<td>20x saline sodium citrate</td>
		</tr>
		<tr>
			<td>Surgical tape</td>
			<td>Fisher Scientific</td>
			<td>12960495</td>
			<td></td>
		</tr>
		<tr>
			<td>Tamoxifen</td>
			<td>Sigma</td>
			<td>T5648</td>
			<td>TAM, inject without allowing the solution to cool too much as compound will drop out of solution. Solution can be re-used &#8211; store at -20&#176;C between uses, do not reheat more than twice.</td>
		</tr>
		<tr>
			<td>TBS/T</td>
			<td>Cell Signalling</td>
			<td>#9997</td>
			<td></td>
		</tr>
		<tr>
			<td>Triethanolamine hydrochloride</td>
			<td>Sigma</td>
			<td>T1502</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-HCL</td>
			<td>Invitrogen</td>
			<td>15567-027</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween20</td>
			<td>Sigma</td>
			<td>TP9416</td>
			<td></td>
		</tr>
		<tr>
			<td>VectaMount</td>
			<td>Vector Labs</td>
			<td>H-5000</td>
			<td></td>
		</tr>
		<tr>
			<td>VectaShield Hardset mounting Medium with DAPI</td>
			<td>Vector Labs</td>
			<td>H-1500</td>
			<td></td>
		</tr>
		<tr>
			<td>Vectastain ABC Kit</td>
			<td>Vector Labs</td>
			<td>PK-4001</td>
			<td></td>
		</tr>
		<tr>
			<td>X-gal</td>
			<td>Promega</td>
			<td>V3941</td>
			<td></td>
		</tr>
		<tr>
			<td>X-gal fixative</td>
			<td>*</td>
			<td>*</td>
			<td>2% formaldehyde, 0.1% glutaraldehyde in 1xPBS</td>
		</tr>
		<tr>
			<td>X-gal stain</td>
			<td>*</td>
			<td>*</td>
			<td>X-gal stain; 200ul X-gal (A) in 50ml solution B (0.214g MgCl2, 0.48g K-ferricyanide, 0.734g K-ferrocyanide in 500ml PBS).&#160; Solution B can be made up oin advance and stored at 4&#176;C</td>
		</tr>
		<tr>
			<td>Xylene</td>
			<td>Fisher Scientific</td>
			<td>X/0200/21</td>
			<td></td>
		</tr>
	</tbody>
</table>

protocols for analyzing the role of paneth cells in regenerating the murine intestine using conditional cre-lox mouse models

A superfície epitelial do intestino de mamífero é um tecido dinâmico que renova a cada 3 - 7 dias. Entender esse processo de renovação identificou uma população de células-tronco rapidamente de bicicleta intestinais (ISC) caracterizados pela sua expressão do gene Lgr5. Estas são suportadas por uma população de células estaminais quiescentes, marcado por Bmi-1 expressão, capaz de substitui-los em caso de danos. Investigar as interações entre essas populações é crucial para entender seu papel na doença e cancro. As ISC existir dentro de criptas na superfície intestinal, esses nichos apoiar a ISC na reposição do epitélio. A interação entre ISC ativos e quiescentes provável envolve outras células diferenciadas dentro do nicho, como já foi anteriormente demonstrado que a &#39;&#39; stemness &#39;&#39; do Lgr5 ISC está intimamente ligada à presença de vizinhos as suas células de Paneth. Usando condicional rato cre-loxmodelos testámos o efeito da delecção da maior parte do ISC activo na presença ou ausência das células de Paneth. Aqui nós descrevemos as técnicas e análises realizados para caracterizar o intestino e demonstrar que as células de Paneth desempenham um papel crucial dentro do nicho ISC em ajudar a recuperação após insulto substancial.

Watch this Scientific Journal Video about Protocols for Analyzing the Role of Paneth Cells in Regenerating the Murine Intestine using Conditional Cre-lox Mouse Models at JoVE.com

Protocols for Analyzing the Role of Paneth Cells in Regenerating the Murine Intestine using Conditional Cre-lox Mouse Models

Células-tronco do epitélio intestinal (ISC) são misturados com células de Paneth. Estas células são diferenciadas progênie do ISC, que suportam o ISC e fornecer proteção antibacteriana. Aqui demonstramos como nós usamos modelos de ratos transgénicos condicionais para estabelecer que as células de Paneth desempenham um papel crucial na manutenção dos epitélio intestinal.

Protocolos para analisar o papel das células Paneth em Regenerar o Intestino Murino utilizando Condicional<em&gt; Cre-lox</em&gt; Mouse Models

The epithelial surface of the mammalian intestine is a dynamic tissue that renews every 3 - 7 days. Understanding this renewal process identified a ...

protocols-for-analyzing-role-paneth-cells-regenerating-murine

Research

JoVE Journal

Developmental Biology

Protocols for Analyzing the Role of Paneth Cells in Regenerating the Murine Intestine using Conditional Cre-lox Mouse Models

17.5K visualizações.  Cardiff University.  Células-tronco do epitélio intestinal (ISC) são misturados com células de Paneth. Estas células são diferenciadas progênie do ISC, que suportam o ISC e fornecer proteção antibacteriana. Aqui demonstramos como nós usamos modelos de ratos transgénicos condicionais para estabelecer que as células de Paneth desempenham um papel crucial na manutenção dos epitélio intestinal. 

Vídeo: Protocols for Analyzing the Role of Paneth Cells in Regenerating the Murine Intestine using Conditional Cre-lox Mouse Models

The Production of Pluripotent Stem Cells from Mouse Amniotic Fluid Cells Using a Transposon System

Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by forced expression of defined transcription factors using different methods. Here, we produced iPS cells from mouse amniotic fluid cells, using a non-viral-based transposon system. All obtained iPS cell lines exhibited characteristics of pluripotent cells, including the ability to differentiate toward derivatives of all three germ layers in vitro and in vivo. This strategy opens up the possibility of using cells from diseased fetuses to develop new therapies for birth defects.

In this study, we generate induced pluripotent stem cells from mouse amniotic fluid cells, using a non-viral-based transposon system.

A produção de células-tronco pluripotentes de rato amniótico células do líquido Usando um Sistema Transposon

Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by forced expression of defined transcription factors using ...

Biologia do Desenvolvimento

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 ...

A RANKL-based Osteoclast Culture Assay of Mouse Bone Marrow to Investigate the Role of mTORC1 in Osteoclast Formation

Osteoclasts are unique bone-resorbing cells that differentiate from the monocyte/macrophage lineage of bone marrow. Dysfunction of osteoclasts may result in a series of bone metabolic diseases, including osteoporosis. To develop pharmaceutical targets for the prevention of pathological bone mass loss, the mechanisms by which osteoclasts differentiate from precursors must be understood. The ability to isolate and culture a large number of osteoclasts in vitro is critical in order to determine the role of specific genes in osteoclast differentiation. Inactivation of the mammalian/mechanistic target of rapamycin complex 1 (TORC1) in osteoclasts can decrease osteoclast number and increase bone mass; however, the underlying mechanisms require further study. In the present study, a RANKL-based protocol to isolate and culture osteoclasts from mouse bone marrow and to study the influence of mTORC1 inactivation on osteoclast formation is described. This protocol successfully resulted in a large number of giant osteoclasts, typically within one week. Deletion of Raptor impaired osteoclast formation and decreased the activity of secretory tartrate-resistant acid phosphatase, indicating that mTORC1 is critical for osteoclast formation.

This manuscript describes a protocol to isolate and culture osteoclasts in vitro from mouse bone marrow, and to study the role of the mammalian/mechanistic target of rapamycin complex 1 in osteoclast formation.

Um baseado em RANKL Osteoclast cultura ensaio de Mouse medula óssea para investigar o papel de mTORC1 na formação de Osteoclast

Osteoclasts are unique bone-resorbing cells that differentiate from the monocyte/macrophage lineage of bone marrow. Dysfunction of osteoclasts may result ...

Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans

Studying the cell biological processes during converting the identities of specific cell types provides important insights into mechanism that maintain and protect cellular identities. The conversion of germ cells into specific neurons in the nematode Caenorhabditis elegans (C. elegans) is a powerful tool for performing genetic screens in order to dissect regulatory pathways that safeguard established cell identities. Reprogramming of germ cells to a specific type of neurons termed ASE requires transgenic animals that allow broad over-expression of the Zn-finger transcription factor (TF) CHE-1. Endogenous CHE-1 is expressed exclusively in two head neurons and is required to specify the glutamatergic ASE neurons fate, which can easily be visualized by the gcy-5prom::gfp reporter. A trans gene containing the heat-shock promoter-driven che-1 gene expression construct allows broad mis-expression of CHE-1 in the entire animal upon heat-shock treatment. The combination of RNAi against the chromatin-regulating factor LIN-53 and heat-shock-induced che-1 over-expression leads to reprogramming of germ cell into ASE neuron-like cells. We describe here the specific RNAi procedure and appropriate conditions for heat-shock treatment of transgenic animals in order to successfully induce germ cell to neuron conversion.

Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans

This protocol describes how to study cellular processes during cell fate conversion in Caenorhabditis elegans in vivo. Using transgenic animals, allowing heat-shock promoter-driven overexpression of the neuron fate-inducing transcription factor CHE-1 and RNAi-mediated depletion of the chromatin-regulating factor LIN-53 germ cell to neuron reprogramming can be observed in vivo.

Aplicação de RNAi e calor-choque-induzida expressão de fator de transcrição para reprogramar as células germinativas de neurônios em c. elegans

Studying the cell biological processes during converting the identities of specific cell types provides important insights into mechanism that maintain ...

Assessing Lysosomal Alkalinization in the Intestine of Live Caenorhabditis elegans

The nematode Caenorhabditis elegans (C. elegans) is a model system that is widely used to study longevity and developmental pathways. Such studies are facilitated by the transparency of the animal, the ability to do forward and reverse genetic assays, the relative ease of generating fluorescently labeled proteins, and the use of fluorescent dyes that can either be microinjected into the early embryo or incorporated into its food (E. coli strain OP50) to label cellular organelles (e.g. 9-diethylamino-5H-benzo(a)phenoxazine-5-one and (3-{2-[(1H,1&#39;H-2,2&#39;-bipyrrol-5-yl-kappaN(1))methylidene]-2H-pyrrol-5-yl-kappaN}-N-[2-(dimethylamino)ethyl]propanamidato)(difluoro)boron). Here, we present the use of a fluorescent pH-sensitive dye that stains intestinal lysosomes, providing a visual readout of dynamic, physiological changes in lysosomal acidity in live worms. This protocol does not measure lysosomal pH, but rather aims to establish a reliable method of assessing physiological relevant variations in lysosomal acidity. cDCFDA is a cell-permeant compound that is converted to the fluorescent fluorophore 5-(and-6)-carboxy-2&#39;,7&#39;-dichlorofluorescein (cDCF) upon hydrolysis by intracellular esterases. Protonation inside lysosomes traps cDCF in these organelles, where it accumulates. Due to its low pKa of 4.8, this dye has been used as a pH sensor in yeast. Here we describe the use of cDCFDA as a food supplement to assess the acidity of intestinal lysosomes in C. elegans. This technique allows for the detection of alkalinizing lysosomes in live animals, and has a broad range of experimental applications including studies on aging, autophagy, and lysosomal biogenesis.

Assessing Lysosomal Alkalinization in the Intestine of Live Caenorhabditis elegans

A step-by-step guide to probe loss of lysosomal acidity in the intestine of C. elegans using the pH-sensitive vital dye 5(6)-carboxy-2&#39;,7&#39;-dichlorofluorescein diacetate (cDCFDA)

Avaliação dos lisossomos Alkalinization no intestino de viver elegans de Caenorhabditis

The nematode Caenorhabditis elegans (C. elegans) is a model system that is widely used to study longevity and developmental pathways. Such studies are ...

Computational Analysis of the Caenorhabditis elegans Germline to Study the Distribution of Nuclei, Proteins, and the Cytoskeleton

The Caenorhabditis elegans (C. elegans) germline is used to study several biologically important processes including stem cell development, apoptosis, and chromosome dynamics. While the germline is an excellent model, the analysis is often two dimensional due to the time and labor required for three-dimensional analysis. Major readouts in such studies are the number/position of nuclei and protein distribution within the germline. Here, we present a method to perform automated analysis of the germline using confocal microscopy and computational approaches to determine the number and position of nuclei in each region of the germline. Our method also analyzes germline protein distribution that enables the three-dimensional examination of protein expression in different genetic backgrounds. Further, our study shows variations in cytoskeletal architecture in distinct regions of the germline that may accommodate specific spatial developmental requirements. Finally, our method enables automated counting of the sperm in the spermatheca of each germline. Taken together, our method enables rapid and reproducible phenotypic analysis of the C. elegans germline.

Computational Analysis of the Caenorhabditis elegans Germline to Study the Distribution of Nuclei, Proteins, and the Cytoskeleton

We present an automated method for three-dimensional reconstruction of the Caenorhabditis elegans germline. Our method determines the number and position of each nucleus within the germline and analyses germline protein distribution and cytoskeletal structure.

Análise computacional do Germline Caenorhabditis elegans , para estudar a distribuição de núcleos, as proteínas e o citoesqueleto

The Caenorhabditis elegans (C. elegans) germline is used to study several biologically important processes including stem cell development, apoptosis, and ...

Visualizing the Node and Notochordal Plate In Gastrulating Mouse Embryos Using Scanning Electron Microscopy and Whole Mount Immunofluorescence

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is the formation of the transient organizers, the node and notochordal plate, from cells that have passed through the primitive streak. The proper formation of these signaling centers is essential for the development of the body plan and techniques to visualize them are of high interest to mouse developmental biologists. The node and notochordal plate lie on the ventral surface of gastrulating mouse embryos around embryonic day (E) 7.5 of development. The node is a cup-shaped structure whose cells possess a single slender cilium each. The proper subcellular localization and rotation of the cilia in the node pit determines left-right asymmetry. The notochordal plate cells also possess single cilia albeit shorter than those of the node cells. The notochordal plate forms the notochord which acts as an important signaling organizer for somitogenesis and neural patterning. Because the cells of the node and notochordal plate are transiently present on the surface and possess cilia, they can be visualized using scanning electron microscopy (SEM). Among other techniques used to visualize these structures at the cellular level is whole mount immunofluorescence (WMIF) using the antibodies against the proteins that are highly expressed in the node and notochordal plate. In this report, we describe our optimized protocols to perform SEM and WMIF of the node and notochordal plate in developing mouse embryos to help in the assessment of tissue shape and cellular organization in wild-type and gastrulation mutant embryos.

The node and notochordal plate are transient signaling organizers in developing mouse embryos that can be visualized using several techniques. Here, we describe in detail how to perform two of the techniques to study their structure and morphogenesis: 1) scanning electron microscopy (SEM); and 2) whole mount immunofluorescence (WMIF).

Visualizando o nó e placa Notochordal em Gastrulating embriões de rato usando microscopia eletrônica e imunofluorescência de montagem inteira

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is ...

Adult Zebrafish Injury Models to Study the Effects of Prednisolone in Regenerating Bone Tissue

Zebrafish are able to regenerate various organs, including appendages (fins) after amputation. This involves the regeneration of bone, which regrows within roughly two weeks after injury. Furthermore, zebrafish are able to heal bone rapidly after trepanation of the skull, and repair fractures that can be easily introduced into zebrafish bony fin rays. These injury assays represent feasible experimental paradigms to test the effect of administered drugs on rapidly forming bone. Here, we describe the use of these 3 injury models and their combined use with systemic glucocorticoid treatment, which exerts bone inhibitory and immunosuppressive effects. We provide a workflow on how to prepare for immunosuppressive treatment in adult zebrafish, illustrate how to perform fin amputation, trepanation of calvarial bones, and fin fractures, and describe how the use of glucocorticoids affects both bone forming osteoblasts and cells of the monocyte/macrophage lineage as part of innate immunity in bone tissue.

Here, we describe 3 adult zebrafish injury models and their combined use with immunosuppressive drug treatment. We provide guidance on imaging of regenerating tissues and on detecting bone mineralization therein.

Modelos de lesão adulto Zebrafish para estudar os efeitos de prednisolona na regeneração de tecido ósseo

Zebrafish are able to regenerate various organs, including appendages (fins) after amputation. This involves the regeneration of bone, which regrows ...

Assessment of Oxidative Damage in the Primary Mouse Ocular Surface Cells/Stem Cells in Response to Ultraviolet-C (UV-C) Damage

The ocular surface is subjected to regular wear and tear due to various environmental factors. Exposure to UV-C radiation constitutes an occupational health hazard. Here, we demonstrate the exposure of primary stem cells from the mouse ocular surface to UV-C radiation. Reactive oxygen species (ROS) formation is the readout of the extent of oxidative stress/damage. In an experimental in vitro setting, it is also essential to assess the percentage of dead cells generated due to oxidative stress. In this article, we will demonstrate the 2&#39;,7&#39;-Dichlorofluoresceindiacetate (DCFDA) staining of UV-C exposed mouse primary ocular surface stem cells and their quantification based on the fluorescent images of DCFDA staining. DCFDA staining directly corresponds to ROS generation. We also demonstrate the quantification of dead and live cells by simultaneous staining with propidium iodide (PI) and Hoechst 3332 respectively and the percentage of DCFDA (ROS positive) and PI positive cells.

Assessment of Oxidative Damage in the Primary Mouse Ocular Surface Cells/Stem Cells in Response to Ultraviolet-C UV-C Damage

This protocol demonstrates the simultaneous detection of reactive oxygen species (ROS), live cells, and dead cells in live primary cultures from mouse ocular surface cells. 2&#39;,7&#39;-Dichlorofluoresceindiacetate, propidium iodide, and Hoechst staining are used to assess the ROS, dead cells, and live cells, respectively, followed by imaging and analysis.

Avaliação de danos oxidativos nas células de superfície ocular/células-tronco do rato primário em resposta ao dano ultravioleta-C (UV-C)

The ocular surface is subjected to regular wear and tear due to various environmental factors. Exposure to UV-C radiation constitutes an occupational ...