Name: induction and testing of hypoxia in cell culture
Uploaded: 2011-08-12T13:00:00
Duration: 7 min 1 s
Description: Watch this Scientific Journal Video about Induction and Testing of Hypoxia in Cell Culture at JoVE.com

1. Hipóxia induzida por solução de 2 CoCl Cloreto de cobalto hexa-hidratado (II) (CoCl 2 • 6H 2 O, MW = 237,9) é um indutor químico da hipóxia induzida por fator de 1,3 8. Este produto é solúvel em água (100 mg / ml), produzindo uma solução clara e vermelho. <ol><li> Prepare uma solução estoque 25 mM em água dd estéril, (preparar imediatamente antes do uso) </li><li> Use CoCl 2 na concentração final de 100μM em seus meios de cultura de células regulares para induzir hipóxia. </li><li> Adicione o CoCl 2 mídia contendo as suas células e incubar as culturas de 24 horas em uma incubadora convencional (37 ° C, 5% C0 2). </li></ol> A concentração acima funciona para as linhas de células que temos testado, mas cada linha celular deve ser testado em várias concentrações (para estabelecer uma curva dose-dependente), bem como em vários tempos de incubação, a fim de limitar a toxicidade relacionada com a droga e otimizar o ensaio. 2. Hipóxia induzida em Modular Incubadora Câmara <ol><li> Preparar pelo menos duas culturas de células idênticas (cultura twin). Culturas de células pode ser em barris, pratos ou travessas cultura. Para abrir a câmara, abre pela primeira vez as duas braçadeiras de plástico branco localizado na tubos ligados à câmara (tubos utilizados para a injeção / purga do gás hipóxico) e abra cuidadosamente o grampo anel de aço. </li><li> Solte o grampo. A tampa e bandejas podem agora ser removido. </li><li> Coloque a cultura de células na câmara hipóxica. Também colocar uma placa de Petri contendo água estéril na câmara para fornecer umidificação adequada das culturas. </li><li> Coloque a cultura de células &quot;gêmeo&quot; em normóxia como controle. </li><li> Verifique se o seu bandejas são garantidos e não em movimento, e depois fechar a câmara com a tampa. Posicionar corretamente a braçadeira anel de aço para garantir o fechamento hermético da câmara e fechá-lo. </li><li> Para criar hipóxia, conectar o tubo a um &quot;tanque de hipóxia&quot;, contendo a 1% da mistura de gases O 2. Se você tiver um medidor de fluxo conectado ao seu tanque de sua câmara estará diretamente conectado a ele (gás tanque de fluxo metros-câmara). Usamos um medidor de fluxo incorporadas em nosso regulador. </li><li> É importante remover a maior parte se não estiver presente todo o oxigênio na câmara e em seus meios, para fazê-lo lavar a câmara através da abertura do tanque de gás a uma vazão de 20 litros por minuto por 7-10 minutos, em seguida, desligar rapidamente o fluxo de gás e fechar completamente a câmara, fechando ambos os grampos branco. </li><li> Retorno da câmara para uma incubadora convencional para o período de tempo desejado. Se você usar grandes culturas, permitem mídia em culturas de-gás para 1-2 horas e depois repetir flush. As etapas acima são baseados nas recomendações do construtor &quot;(Billups-Rothenberg, Inc). Certifique-se de tanque de gás são devidamente protegidas em todos os tempos. </li></ol> Notas: <ul><li> , A fim de eliminar o O 2 contidas na mídia, é aconselhável a re-gás na câmara de uma vez depois de 1-3 horas. </li><li> Por tempo de incubação mais longo do que 48 horas também é aconselhado a re-câmara do gás. </li><li> Sensores de oxigênio (eletrodos / manômetro) que permitem medições do O 2 contidos em células / câmara irá proporcionar uma medição mais precisa do O intracelular / câmara de 2 contêm). </li><li> A cultura de células em intervalos de tempo diferentes para fazer uma curva de tempo-seria ajudar a determinar a expressão de tempo ideal de HIF-1α em suas células particular. </li></ul> 3. Avaliação de hipóxia <ol><li> HIF-1 de detecção de α por western blot. <ol><li> Reabrir a sua câmara como descrito na seção 2.2 e colocar imediatamente suas culturas no gelo. </li><li> Lyse hipóxia células tratadas e não-tratados com 5% de solução SDS nas placas, em seguida, transferir o lyzate célula para tubos, sonicate, spindown os restos celulares e recolher o sobrenadante. </li><li> Concentração medida de proteína usando kit BCA, prepare amostra pela adição de tampão de carregamento e aquecimento a 95 ° C por 5 min. </li><li> Electroforese de proteínas em um gel SDS 8% de poliacrilamida e transferência para membranas de nitrocelulose. </li><li> Bloquear a membrana em PBS contendo 5% de leite sem gordura seco e 0,1% Tween 20 à temperatura ambiente por 1 hora ou a 4 ° C durante a noite em shaker. </li><li> Immunoblot durante a noite com anti-HIF-1α anticorpo primário monoclonal (1 / 600) no mesmo tampão a 4 ° C. </li><li> Lavar 3 vezes em PBS contendo 0,1% Tween 20 à temperatura ambiente, 5min de cada vez e incube com HRP-anticorpo secundário (1 / 2000) em PBS + 0,1% Tween 20 por 45 min. </li><li> Lavar 3 vezes em PBS contendo 0,1% Tween 20 à temperatura ambiente, 5min / hora. </li><li> Use Pierce kit ECL e X-ray filme para mostrar a banda de proteína </li></ol></li><li> Elemento Responsive hipóxia (HRE). HIF-1α regula numerosos genes (ou seja, VEGF, EPO) por ligação a uma seqüência chamada elemento regulador hipóxia (HRE). Usando HRE associado a um gene marcador it é possível detectar atividade de HIF 9. Para utilizar este método, primeiro você precisa transfectar suas células com um plasmídeo HRE-luciferase usando um método de transfecção adaptado às suas células. Por exemplo usamos Lipofectamine 2000. Células precisam ser transfectadas pelo menos 4 horas antes de ser incubadas em hipóxia e normóxia. Desta vez, permite que o DNA para entrar nas células, para que este primeiro passo não é afetada pela hipóxia. O sinal de luciferase é detectada através de um kit de ensaio de luciferase. <ol><li> Incubar a sua HRE-transfectadas células em hipóxia na câmara modular ou usar HRE-transfectadas células incubadas com CoCl 2, incluem um controle normóxia. </li><li> Após o período de incubação desejado, remova o meio de crescimento das células. </li><li> Enxágüe células em PBS, remova o PBS. </li><li> Dispense 400μl do reagente de lise 1X em placa de cultura e raspar as células em anexo, depois transferi-los para um tubo de micro. </li><li> Pellet detritos por centrifugação breve. </li><li> 20μl mistura de células lisados ​​sobrenadante com 100μl de reagente de ensaio de luciferase e medir a luminescência com um luminômetro. </li></ol></li></ol> 4. Resultados representativos: Em células K562 (linha de células humanas de leucemia) cultivados dois dias em baixa de oxigênio, comparado à normóxia, hipóxia induz um aumento do HIF-1α proteína que foi detectada por western blot (Figura 1). Usando HRE-luciferase modificado 293 células (linhagem de células embrionárias de rins) cultivados em hipóxia, um aumento significativo de HIF-1α atividade foi detectada em células hipóxicas (Figura 2). <img src="/files/ftp_upload/2899/2899fig1.jpg" alt="Figura 1"/> Figura 1: Aumente o HIF-1α em células hipóxicas. K562 células foram cultura em normóxia e hipóxia (câmara hipóxica) por 48 horas e analisadas por western blot usando um anticorpo específico para o HIF-1α. Um anticorpo específico para actina foi usado para o controle de carga. <img src="/files/ftp_upload/2899/2899fig2.jpg" alt="Figura 2"/> Figura 2: HIF-1α atividade. HRE-luciferase modificado 293 células foram cultivadas em hipóxia e normóxia durante 48 horas e, em seguida, lisados ​​para detectar o sinal luciferase usando um kit de ensaio de luciferase e um luminómetro. Os resultados são expressos como a unidade de luminescência relativa (RLU).

<ol>
	<li>Swinson, D. E., O'Byrne, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactions+between+hypoxia+and+epidermal+growth+factor+receptor+in+non-small-cell+lung+cancer.">Interactions between hypoxia and epidermal growth factor receptor in non-small-cell lung cancer.</a> Clin Lung Cancer. 7, 250-256 (2006).</li><li>van Laarhoven, H. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia+in+relation+to+vasculature+and+proliferation+in+liver+metastases+in+patients+with+colorectal+cancer.">Hypoxia in relation to vasculature and proliferation in liver metastases in patients with colorectal cancer.</a> Int J Radiat Oncol Biol Phys. 64, 473-482 (2006).</li><li>Hockel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intratumoral+pO2+predicts+survival+in+advanced+cancer+of+the+uterine+cervix.">Intratumoral pO2 predicts survival in advanced cancer of the uterine cervix.</a> Radiother Oncol. 26, 45-50 (1993).</li><li>Semenza, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIF-1+and+human+disease:+one+highly+involved+factor.">HIF-1 and human disease: one highly involved factor.</a> Genes Dev. 14, 1983-1991 (2000).</li><li>Semenza, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia-inducible+factor+1:+master+regulator+of+O2+homeostasis.">Hypoxia-inducible factor 1: master regulator of O2 homeostasis.</a> Curr Opin Genet Dev. 8, 588-594 (1998).</li><li>Tatum, 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=Hypoxia:+importance+in+tumor+biology,+noninvasive+measurement+by+imaging,+and+value+of+its+measurement+in+the+management+of+cancer+therapy.">Hypoxia: importance in tumor biology, noninvasive measurement by imaging, and value of its measurement in the management of cancer therapy.</a> Int J Radiat Biol. 82, 699-757 (2006).</li><li>Brahimi-Horn, M. C., Pouyssegur, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIF+at+a+glance.">HIF at a glance.</a> J Cell Sci. 122, 1055-1057 (2009).</li><li>Piret, J. P., Mottet, D., Raes, M., Michiels, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CoCl2,+a+chemical+inducer+of+hypoxia-inducible+factor-1,+and+hypoxia+reduce+apoptotic+cell+death+in+hepatoma+cell+line+HepG2.">CoCl2, a chemical inducer of hypoxia-inducible factor-1, and hypoxia reduce apoptotic cell death in hepatoma cell line HepG2.</a> Ann N Y Acad Sci. 973, 443-447 (2002).</li><li>Emerling, B. M., Weinberg, F., Liu, J. L., Mak, T. W., Chandel, N. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PTEN+regulates+p300-dependent+hypoxia-inducible+factor+1+transcriptional+activity+through+Forkhead+transcription+factor+3a+(FOXO3a).">PTEN regulates p300-dependent hypoxia-inducible factor 1 transcriptional activity through Forkhead transcription factor 3a (FOXO3a).</a> Proc Natl Acad Sci U S A. 105, 2622-2627 (2008).</li></ol>

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Proliferação celular e viabilidade em condições de hipóxia variar muito, dependendo dos tipos de células. Portanto, você deve ajustar o número de células ou o número de culturas placas você começa com a certeza que terá número suficiente de células / proteínas para suas experiências. O método de cloreto de cobalto tem a vantagem de ser barato e rápido. Este produto imita hipóxia induzindo HIF-1/3α mas pode também regulam outros genes, certifique-se este produto está adaptado ao seu projeto, verificando o que outros efeitos pode ter sobre a função e fenótipo de suas células em particular, independentemente da &quot;imitam- efeito &quot;hipóxia. Outro medicamento também usado para imitar a hipóxia é o mesilato de desferroxamina (DFO, utilizado numa concentração de 100 mM final). O uso dessas drogas permite que o experimentador para abrir a placa de cultura / prato / frasco muitas vezes sem afetar a &quot;condição de hipóxia&quot;. O nível de oxigênio contido na mistura de gás pode variar de acordo com suas experiências e tipos de células como os valores variam de acordo com hipóxia dos tecidos e tipos celulares. De fato, algumas células são hipóxica em 5% O 2 outros precisam menos de 1% O 2 a ser hipóxica. 5% de CO 2 é adicionado à mistura de gás para estabilizar o pH das culturas, o resto do gás é geralmente nitrogênio. Câmaras hipóxicas têm a vantagem de não usar drogas que pode alternar o comportamento das células, independentemente da tensão de oxigênio. No entanto, nem todos os tipos de experimentação pode ser feito como o oxigênio re-entra na câmara em cada abertura e, assim, diminui a hipóxia. Você deve considerar este fator em seus experimentos; hipóxia / reoxigenação é uma condição específica que podem afetar alguns tipos de células. Uma alternativa é a utilização de estações de trabalho hipóxia (ligado a tanques de pré-mistura de gás ou de sistemas de gás de mistura) ou maior incubadora hipóxia (câmara de processamento de hipóxia com porta-luvas), que permite a experimentação de mudar de mídia e manipular as células em ambiente hipóxico contínua. Várias câmaras hipóxicas foram comercializados nos últimos dez anos e deve ser escolhido de acordo com o seu laboratório utilizado, projetos, espaço, tamanho, orçamento e. Sempre garantir o bom uso e condição da sua câmara para garantir condições de cultivo correto. Em geral quando se usa uma câmara, o nível de hipóxia pode ser modulada, selecionando as misturas de gases diversos (ou seja, 1%, 5% a 10% de oxigênio). Em relação à detecção de HIF-1α, é importante saber que algumas linhas de células cancerígenas HIF-1α expressar em normóxia. Portanto, é fundamental usar um normoxia-controle para determinar o nível basal de HIF nestas linhas celulares. HIF-1α também pode estar presente em normóxia não-malignas em células após estimulação celular ou stress. Isso também poderia ocorrer se essas células estão famintos, certifique-se culturas de células são o alimentar adequadamente e mantido.

<table border="1"><tbody><tr><th> Nome do reagente </th><th> Companhia </th><th> Número de catálogo </th></tr><tr><td> Anti-HIF-1α </td><td> Invitrogen </td><td> 458400 </td></tr><tr><td> Cloreto de cobalto (II) </td><td> Sigma </td><td> C8661-25G </td></tr><tr><td> Câmara incubadora </td><td> Billups-Rothenberg </td><td> MIC-101 </td></tr><tr><td> HRE-luciferase plasmídeo </td><td> Adgene </td><td> Plasmídeo 26731 </td></tr></tbody></table>

induction and testing of hypoxia in cell culture

Hipóxia é definida como a redução ou falta de oxigênio nos órgãos, tecidos ou células. Esta diminuição da tensão de oxigênio pode ser devido a uma oferta reduzida de oxigênio (causas incluem rede de vasos sanguíneos insuficientes, defeito dos vasos sangüíneos e anemia) ou a um aumento do consumo de oxigênio relativo ao fornecimento (causada por uma maior taxa de proliferação celular súbita) . Hipóxia pode ser fisiológica ou patológica como em tumores sólidos 1-3 reumatóide etc artrite, aterosclerose, ... Cada tecidos e células têm uma capacidade diferente para se adaptar a esta nova condição. Durante a hipóxia, hipóxia induzida fator alfa (HIF) é estabilizado e regula vários genes como aqueles envolvidos na angiogênese ou transporte de oxigênio 4. A estabilização desta proteína é a marca registrada de hipóxia, portanto, a detecção de HIF é rotineiramente usado para triagem de 07/05 hipóxia. Neste artigo, propomos dois métodos simples para induzir hipóxia em culturas de células de mamíferos e testes simples para avaliar o estado hipóxico dessas células.

Watch this Scientific Journal Video about Induction and Testing of Hypoxia in Cell Culture at JoVE.com

Induction and Testing of Hypoxia in Cell Culture

Aqui propomos métodos simples para induzir hipóxia em culturas de células e testes simples para avaliar o estado hipóxico das culturas.

Indução de hipóxia e Testes em Cultura de Células

Hypoxia is defined as the reduction or lack of oxygen in organs, tissues, or cells.  This decrease of oxygen tension can be due to a reduced supply in ...

induction-and-testing-of-hypoxia-in-cell-culture

Research

JoVE Journal

Biology

Culture of Mouse Neural Stem Cell Precursors

Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase our understanding of the nervous system and may allow us to develop treatments for currently incurable brain diseases and injuries. In addition, stem cells should be used for stem cell research aimed at the detailed study of mechanisms of neural differentiation and transdifferentiation and the genetic and environmental signals that direct the specialization of the cells into particular cell types.  This video demonstrates a technique used to disaggregate cells from the embryonic day 12.5 mouse dorsal forebrain. The dissection procedure includes harvesting E12.5 mouse embryos from the uterus, removing the "skin" with fine dissecting forceps and finally isolating pieces of cerebral cortex. Following the dissection, the tissue is digested and mechanically dissociated. The resuspended dissociated cells are then cultured in "stem cell" media that favors growth of neural stem cells.

This video describes the method used for isolation of neuroprecursors from the developing cortex of embryonic mice. The procedure for removing embryos from the uterus, dissecting the cortical tissue, and digesting the isolated cerebral cortex is shown.

Cultura de rato precursores das células-tronco neurais

Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase ...

Biologia

Induction and Monitoring of Adoptive Delayed-Type Hypersensitivity in Rats

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of an antigen against which the immune system has been primed. The inflammatory reaction is characterized by redness and swelling of the site of antigenic challenge. It is a convenient model to determine the in vivo efficacy of immunosuppressants. Cutaneous DTH can be induced either by adoptive transfer of antigen-specific T lymphocytes or by active immunization with an antigen, and subsequent intradermal challenge with the antigen to induce the inflammatory reaction in a given skin area. DTH responses can be induced to various antigens, for example ovalbumin, tuberculin, tetanus toxoid, or keyhole limpet hemocyanin. Such reactions can also be induced against autoantigen, for example to myelin basic protein (MBP) in rats with experimental autoimmune encephalomyelitis induced with MBP, an animal model for multiple sclerosis (1).
Here we demonstrate how to induce an adoptive DTH reaction in Lewis rats. We will first stimulate ovalbumin-specific T cells in vitro and inject these activated cells intraperitoneally to naive rats. After allowing the cells to equilibrate in vivo for 2 days, we will challenge the rats with ovalbumin in the pinna of one ear, while the other ear wil receive saline. The inflammatory reaction will be visible 3-72 hours later and ear thickness will be measured as an indication of DTH severity.

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T (TEM) lymphocytes. Here we demonstrate how to activate antigen-specific TEM cells, induce adoptive DTH in Lewis rats and monitor the inflammatory response.

Indução e Monitoramento de hipersensibilidade tardia-Type Adoptive em Ratos

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of ...

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering1-3. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart1-3. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery1-3. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration4,5. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity6-8 (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic9-11. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules12 (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of cardioblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human cardiac progenitors and functional cardiomyocytes for cardiovascular repair.

Derivação eficiente dos recursos humanos Precursores cardíaca e Cardiomyocytes pluripotentes a partir de células estaminais embrionárias humanas com a indução de moléculas pequenas

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based ...

Isolation and Primary Culture of Rat Hepatic Cells

Primary hepatocyte culture is a valuable tool that has been extensively used in basic research of liver function, disease, pathophysiology, pharmacology and other related subjects. The method based on two-step collagenase perfusion for isolation of intact hepatocytes was first introduced by Berry and Friend in 1969 1 and, since then, has undergone many modifications. The most commonly used technique was described by Seglenin 1976 2. Essentially, hepatocytes are dissociated from anesthetized adult rats by a non-recirculating collagenase perfusion through the portal vein. The isolated cells are then filtered through a 100 &mu;m pore size mesh nylon filter, and cultured onto plates. After 4-hour culture, the medium is replaced with serum-containing or serum-free medium, e.g. HepatoZYME-SFM, for additional time to culture. These procedures require surgical and sterile culture steps that can be better demonstrated by video than by text. Here, we document the detailed steps for these procedures by both video and written protocol, which allow consistently in the generation of viable hepatocytes in large numbers.

Primary hepatocytes provide a valuable tool to evaluate biochemical, molecular, and metabolic functions in a physiologically relevant experimental system. We describe a reliable protocol for rat in situ liver perfusion, which consistently generates viable hepatocytes up to 1.0 &times; 108 cells per preparation with cell viability between 88 ~ 96%.

Isolamento e cultura primária de células hepáticas de ratos

Primary hepatocyte culture is a valuable tool that has been extensively used in basic research of liver function, disease, pathophysiology, pharmacology ...

The Slice Culture Method for Following Development of Tooth Germs In Explant Culture

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental biologist. For many organs it is difficult to access developing tissue to allow monitoring during ex vivo culture. The slice culture method allows access to tissue so that morphogenetic movements can be followed and specific cell populations can be targeted for manipulation or lineage tracing.
In this paper we describe a method of slice culture that has been very successful for culture of tooth germs in a range of species. The method provides excellent access to the tooth germs, which develop at a similar rate to that observed in vivo, surrounded by the other jaw tissues. This allows tissue interactions between the tooth and surrounding tissue to be monitored. Although this paper concentrates on tooth germs, the same protocol can be applied to follow development of a number of other organs, such as salivary glands, Meckel&#39;s cartilage, nasal glands, tongue, and ear.

Here we detail a method to culture tooth germs in mandible slices using a tissue chopper. This method allows unique access to the tooth during development, providing excellent opportunity for manipulation and lineage tracing, not available using more traditional culture methods.

O método de cultura fatia para acompanhar o desenvolvimento de germes dentários Em Explant Cultura

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental ...

Isolation, Culture, and Transplantation of Muscle Satellite Cells

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal nuclei in muscle fibers. In adult muscle, satellite cells are normally mitotically quiescent. Following injury, however, satellite cells initiate cellular proliferation to produce myoblasts, their progenies, to mediate the regeneration of muscle. Transplantation of satellite cell-derived myoblasts has been widely studied as a possible therapy for several regenerative diseases including muscular dystrophy, heart failure, and urological dysfunction. Myoblast transplantation into dystrophic skeletal muscle, infarcted heart, and dysfunctioning urinary ducts has shown that engrafted myoblasts can differentiate into muscle fibers in the host tissues and display partial functional improvement in these diseases. Therefore, the development of efficient purification methods of quiescent satellite cells from skeletal muscle, as well as the establishment of satellite cell-derived myoblast cultures and transplantation methods for myoblasts, are essential for understanding the molecular mechanisms behind satellite cell self-renewal, activation, and differentiation. Additionally, the development of cell-based therapies for muscular dystrophy and other regenerative diseases are also dependent upon these factors.

However, current prospective purification methods of quiescent satellite cells require the use of expensive fluorescence-activated cell sorting (FACS) machines. Here, we present a new method for the rapid, economical, and reliable purification of quiescent satellite cells from adult mouse skeletal muscle by enzymatic dissociation followed by magnetic-activated cell sorting (MACS). Following isolation of pure quiescent satellite cells, these cells can be cultured to obtain large numbers of myoblasts after several passages. These freshly isolated quiescent satellite cells or ex vivo expanded myoblasts can be transplanted into cardiotoxin (CTX)-induced regenerating mouse skeletal muscle to examine the contribution of donor-derived cells to regenerating muscle fibers, as well as to satellite cell compartments for the examination of self-renewal activities.

The isolation and culture of a pure population of quiescent satellite cells, a muscle stem cell population, is essential to the understanding of muscle stem cell biology and regeneration, as well as stem cell transplantation for therapies in muscular dystrophy and other degenerative diseases.&#160;

Isolamento, cultura e transplante de células musculares satélite

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal ...

Analysis of Global RNA Synthesis at the Single Cell Level following Hypoxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a particular transcriptional program in order to mount an appropriate and coordinated cellular response. The cell possesses several oxygen sensor enzymes that require molecular oxygen as cofactor for their activity. These range from prolyl-hydroxylases to histone demethylases. The majority of studies analyzing cellular responses to hypoxia are based on cellular populations and average studies, and as such single cell analysis of hypoxic cells are seldom performed. Here we describe a method of analysis of global RNA synthesis at the single cell level in hypoxia by using Click-iT RNA imaging kits in an oxygen controlled workstation, followed by microscopy analysis and quantification.&nbsp; Using cancer cells exposed to hypoxia for different lengths of time, RNA is labeled and measured in each cell. This analysis allows the visualization of temporal and cell-to-cell changes in global RNA synthesis following hypoxic stress.

We describe a technique for analysis of global RNA synthesis in hypoxia using imaging. Click-chemistry labeling of RNA has not previously been performed under hypoxia and allows visualization of global RNA changes at the single cell level. This approach complements the existing averaged RNA techniques, allowing direct visualization of cell-to-cell changes in global RNA synthesis.

Análise da Global RNA Síntese no nível da célula única seguinte hipóxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a ...

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, is expressed in neurons in response to various stimuli. The protein product can be readily detected with immunohistochemical techniques leading to the use of c-FOS detection to map groups of neurons that display changes in their activity. In this article, we focused on the identification of brainstem neuronal populations involved in the ventilatory adaptation to hypoxia or hypercapnia. Two approaches were described to identify involved neuronal populations in vivo in animals and ex vivo in deafferented brainstem preparations. In vivo, animals were exposed to hypercapnic or hypoxic gas mixtures. Ex vivo, deafferented preparations were superfused with hypoxic or hypercapnic artificial cerebrospinal fluid. In both cases, either control in vivo animals or ex vivo preparations were maintained under normoxic and normocapnic conditions. The comparison of these two approaches allows the determination of the origin of the neuronal activation i.e., peripheral and/or central. In vivo and ex vivo, brainstems were collected, fixed, and sliced into sections. Once sections were prepared, immunohistochemical detection of the c-FOS protein was made in order to identify the brainstem groups of cells activated by hypoxic or hypercapnic stimulations. Labeled cells were counted in brainstem respiratory structures. In comparison to the control condition, hypoxia or hypercapnia increased the number of c-FOS labeled cells in several specific brainstem sites that are thus constitutive of the neuronal pathways involved in the adaptation of the central respiratory drive.

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo.

A proteína c-Fos Detecção imuno: Uma ferramenta útil como um marcador de vias centrais envolvidos em respostas fisiológicas específicas<em&gt; In Vivo</em&gt; e<em&gt; Ex Vivo</em

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, ...

Detection of RNA-binding Proteins by In Vitro RNA Pull-down in Adipocyte Culture

RNA-binding proteins (RBPs) are emerging as a regulatory layer in the development and function of adipose. RBPs play a key role in the gene expression regulation at posttranscriptional levels by affecting the stability and translational efficiency of target mRNAs. RNA pull-down technique has been widely used to study RNA-protein interaction, which is necessary to elucidate the mechanism underlying RBPs&#39; as well as long non-coding RNAs&#39; (lncRNAs) function. However, the high lipid abundance in adipocytes poses a technical challenge in conducting this experiment. Here a detailed RNA pull-down protocol is optimized for primary adipocyte culture. An RNA fragment from androgen receptor&#39;s (AR) 3&#39; untranslated region (3&#39;UTR) containing an adenylate-uridylate-rich elementwas used as an example to demonstrate how to retrieve its RBP partner, HuR protein, from adipocyte lystate. The method described here can be applied to detect the interactions between RBPs and noncoding RNAs, as well as between RBPs and coding RNAs.

Detection of RNA-binding Proteins by In Vitro RNA Pull-down in Adipocyte Culture

An RNA pull-down protocol is optimized here for detection of interactions between RNA-binding proteins (RBPs) and noncoding as well as coding RNAs. An RNA fragment from androgen receptor (AR) was used as an example to demonstrate how to retrieve its RBP from lystate of primary brown adipocytes.

Detecção de proteínas de ligação a ARN pela<em&gt; In Vitro</em&gt; RNA Pull-down em Cultura adipócito

RNA-binding proteins (RBPs) are emerging as a regulatory layer in the development and function of adipose. RBPs play a key role in the gene expression ...

Optimized Scratch Assay for In Vitro Testing of Cell Migration with an Automated Optical Camera

Cell migration is an important process that influences many aspects of health, such as wound healing and cancer, and it is, therefore, crucial for developing methods to study the migration. The scratch assay has long been the most common in vitro method to test compounds with anti- and pro-migration properties because of its low cost and simple procedure. However, an often-reported problem of the assay is the accumulation of cells across the edge of the scratch. Furthermore, to obtain data from the assay, images of different exposures must be taken over a period of time at the exact same spot to compare the movements of the migration. Different analysis programs can be used to describe the scratch closure, but they are labor intensive, inaccurate, and forces cycles of temperature changes. In this study, we demonstrate an optimized method for testing the migration effect, e.g. with the naturally occurring proteins Human- and Bovine-Lactoferrin and their N-terminal peptide Lactoferricin on the epithelial cell line HaCaT. A crucial optimization is to wash and scratch in PBS, which eliminates the aforementioned accumulation of cells along the edge. This could be explained by the removal of cations, which have been shown to have an effect on keratinocyte cell-cell connection. To ensure true detection of migration, pre-treating with mitomycin C, a DNA synthesis inhibitor, was added to the protocol. Finally, we demonstrate the automated optical camera, which eliminates excessive temperature cycles, manual labor with scratch closure analysis, while improving on reproducibility and ensuring analysis of identical sections of the scratch over time.

Optimized Scratch Assay for In Vitro Testing of Cell Migration with an Automated Optical Camera

Here we describe a procedure to test the cell migration in vitro with an automated optical camera microscope. The scratch assay has been widely used where the closure of the scratch is followed for a set period. The optical microscope enables dependable and cheap detection of cell migration.