We would like to acknowledge Susan Gray and Umadevi Chalasani for their help with technical aspects of the hepatocyte isolation protocol. This work was supported by NIDDK grant 5R01DK089185 (to M.P. Cooper) and the DERC Pilot and Feasibility Program at UMMS (to M.P. Cooper).

Todos experimentação animal deve ser realizado em conformidade com os regulamentos locais e federais e com a aprovação de uma IACUC e segurança de radiação administração institucional. 1. Preparação <ol><li> Vários dias antes do ensaio, descongelar a garrafa de 500 ml de fígado Digest Médio (LDM) e recongelar ~ 35 ml de partes alíquotas em tubos cónicos de 50 ml. Armazenar a -20 ° C até serem necessárias. </li><li> Um dia antes do ensaio, pré-limpas esterilizar instrumentos de dissecação por autoclave. </li><li> No dia do ensaio, tratar a quantidade necessária de placas de cultura de 24 poços com colagénio. <ol><li> Misturar 1 parte de 3 mg / mL de colagénio de cauda de rato com 50 partes de PBS. Adicionar cerca de 500 uL a cada poço de uma placa de 24 poços e incuba-se durante 3-5 minutos à temperatura ambiente (TA). Remova a placa de colágeno e permitir ao ar seco na capa. Repetir pelo menos uma vez adicional. Nota: revestimento de colágeno pode ser realizada até uma semana em anúncioVance e as placas armazenadas a 4 ° C em filme plástico selado. </li></ol></li><li> Prepare LDM para ensaio: LDM Descongelar e aquecer a 37 ° C e ajustar o pH a 7,4 utilizando KOH 1N. Filtrar usando filtro de seringa de 0,2 um e coloque em um 42 ° C banho de água de recirculação. </li><li> Aqueça 25 ml de fígado Perfusão Médio a 42 ° C em banho de recirculação de água. </li><li> Prepare a 90% de sílica coloidal revestido com uma solução de polivinilpirrolidona: Adicione 1 ml de DPBS 10x a 9 ml de sílica coloidal revestida com polivinilpirrolidona. Ajustar o pH para 7,4 utilizando HCl 0,1 N. Filtrar com um filtro de seringa estéril de 0,2 um. Armazenar à temperatura ambiente. </li><li> Quente meio de plaqueamento de 37 ° C. </li></ol> 2. Isolamento de principal do mouse hepatócitos <ol><li> Configure bomba peristáltica, tubulação, e mesa de dissecção: Esterilizar tubulação por lavagem com etanol a 5 ml de 70% em água destilada, seguido por 10 ml de água estéril. Coloque tubulação no fígado Perfusão Médio e executar bomba para enchertodo o comprimento do tubo. </li><li> Sacrifique rato pelo método aprovado institucionalmente. </li><li> Dissecar aberto a cavidade abdominal: Pulverizar o abdômen do rato generosamente com etanol 70%. Com uma tesoura de extremidade romba, fazer uma incisão na linha média através da derme do comprimento do abdómen e reflectir lateralmente. Adicione uma incisão semelhante no peritoneu para expor as vísceras. <ol><li> Utilizando um instrumento rombo, deslocar os intestinos suavemente para expor a vasculatura abdominal Localizar a veia cava inferior abdominal (IVC) e colocar uma sutura por baixo do vaso sanguíneo, distai em relação à veia renal </li></ol></li><li> Distalmente à sutura, colocar uma agulha e cateter na veia cava inferior, avançando para além do nível da sutura. Com a agulha ainda no lugar, amarrar a sutura ao redor do cateter para segurá-la no lugar. Remova cuidadosamente a agulha. Se isso for feito correctamente, o sangue com fluxo através do cateter. </li><li> Usando uma pipeta, encher o restante da área no meio de perfusão com cateter, assegurandoque nem o ar está presente. Com muito cuidado, coloque a tubulação para o cateter. </li><li> Dissecar aberto da cavidade pulmonar: refletir suavemente os lóbulos superiores do fígado para expor o diafragma. Perfurar cuidadosamente o diafragma com uma tesoura ponta afiada, em seguida, fazer uma incisão lateral para expor a cavidade pleural, tendo o cuidado de evitar a vesícula biliar e vasculatura pleural. Coloque um grampo de bulldog em torno da veia cava inferior torácica apenas proximal à veia hepática. </li><li> Corte a veia porta e ligar a bomba a 3 - 4 ml / min. Perfundir com o fígado Fígado Perfusão médio durante 5 min, utilizando aproximadamente 20 ml de meio de perfusão. Nota: O fígado deve mudar imediatamente de vermelho para cinza / tan. Se porções do fígado permanecer vermelho, isso provavelmente indica má perfusão, ea probabilidade de isolamento bem sucedido é muito reduzido. Durante a perfusão, tenha cuidado para garantir o meio não correr para fora e que não há bolhas de entrar na tubulação. </li><li> Após a 5 min de incubação, parara bomba e tubo para transferir o fígado Digest Médio. Reiniciar a bomba e perfundir o fígado por mais 10 - 15 minutos (até que o meio é esgotada). </li><li> No final da perfusão, parar a bomba. O fígado deve ter um tom rosado e aparecer um pouco alargada. Extirpar o fígado por dissecção cuidadosa. Remover a vesícula biliar e transferir o fígado a 10 cm prato de cultura de tecidos. </li><li> Em uma cabine de segurança biológica, adicionar 10 ml de chapeamento Médio (Tabela 1) para o fígado. Raspe o fígado utilizando quer uma pinça ou um escalpelo para remover os hepatócitos. Filtra-se a suspensão através de um filtro de células de 100 mm e transferência para um tubo de 50 ml. Lave a placa com um adicional de 10 ml de Galvanização Médio e piscina no tubo de 50 ml. </li><li> Agregar as células por centrifugação durante 5 min a 350 xg, 4 ° C. </li><li> Aspirar médio e pellet ressuspender em 10 ml de Galvanização Médio e adicionar 10 ml de 90% de sílica coloidal revestido com polyvinylpyrrolidone. Misture delicadamente e centrifugar como na etapa 2.11. Após centrifugação, uma camada de células mortas vai ser flutuante na parte superior da mistura, enquanto que as células vivas irá sedimentar para o fundo. </li><li> Aspirar as células mortas e meio. Lavar 2 vezes com 20 ml de chapeamento Médio, centrifugar como em 2.11. </li><li> Ressuspender as células em 10 ml de chapeamento meio. Contar as células com um hemocitómetro e colocar 9 x 10 4 células / poço em pratos de 24 poços de cultura tratados com colagénio. Incubar em 37 ° C de cultura de tecidos incubadora durante 2 horas. Cada placa pode ser usado tanto para o ensaio de oxidação de ácido gordo ou o ensaio Lipogênese. </li><li> Opcionalmente, para alterar poços Meio de Manutenção (Tabela 1) e a cultura a 37 ° C. As células podem ser cultivadas durante 2 - 3 dias, sem afectar os resultados do ensaio. </li></ol> 3. Ácidos Graxos Oxidação Assay Aviso: O uso de radioactividade pode ser perigoso. Todas as compras, armazenamento, manipulação, e disposal de material radioativo deve ser realizado em conformidade com, estado, e regulamentos e diretrizes federais institucionais. <ol><li> 16 - 20 h antes do ensaio, células de lavar 2 vezes com PBS quente. Mudar as células ao soro inanição meio isento de soro (Tabela 1) com 20 nM de glucagon e incubar durante a noite a 37 ° C. Nota: Por causa de soro fetal bovino contém uma concentração desconhecida de hormônios metabólicos (por exemplo, insulina, glucagon), soro de morrer de fome as células para remover quaisquer efeitos de confusão que isso pode ter sobre o ensaio. As células são viáveis ​​em soro fome Médio para&gt; 24 hr. Tratamento glucagon é utilizado para estimular a oxidação do ácido gordo no interior dos hepatócitos. </li><li> Na manhã do dia do ensaio, preparar a pré-incubação Médio: Ressuspender uma quantidade apropriada de palmitato de sódio em água ultrapura para fazer uma solução 100 mM e aquecimento a 70 ° C durante 10 min. Entretanto, a quantidade necessária preparar (0,5 ml por poço de uma placa de 24 poços)de DMEM com 25 mM de HEPES, 1% de BSA Fracção V, e 20 nM de glucagon. Aquece-se a 37 ° C. <ol><li> Uma vez solubilizado, Palmitato de adicionar a uma concentração final de 250 uM para a forma. Mudar hepatócitos para a pré-incubação médio e incubar a 37 ° C durante 2 horas. Reservar alguns A pré-incubação do meio no 37 ° C, para utilização posterior. </li></ol></li><li> Durante a incubação, seco, uma quantidade adequada de 14 C-palmitato (0,5 uCi / poço) por evaporação sob atmosfera de azoto. <ol><li> Por exemplo, para medir 24 amostras numa placa de 24 poços, 120 ul de transferir 0,1 uCi / ml de C-14 Palmitato de um tubo de 1,5 ml. Lentamente, evapora-se o solvente etanol por sopragem de azoto gasoso através da solução a partir de uma distância de 3-5 cm numa hotte. O solvente deverá evaporar-se em cerca de 30 - 40 min, deixando a seco C-14 Palmitato no fundo do tubo. </li></ol></li><li> Aproximadamente 15 minutos antes do final da incubação, ressuspender o 14C-Palmitato em NaOH 0,1 N (12,5 mL / uCi). Incubar a 70 ° C durante 10 min. Adicione três volumes de quente Pré-Incubação Médio e misture pipetando cima e para baixo. </li><li> Pico de cada poço com 25 uL de 14 C diluída-palmitato. Misturar agitando suavemente a placa e incubar a 37 ° C durante 90 min. Esta é a placa de ensaio. </li><li> Durante a incubação, preparar a Placa de filtro de papel (Figura 1). <ol><li> Remova a tampa de uma estéril placa de 24 poços. Coloque um 2 cm x 2 cm pedaço de papel de filtro na parte inferior de cada um dos poços. Sobrepor a placa com um pedaço de 4 &quot;x 7&quot; parafilme. </li><li> Usando um grande objecto rectangular, tal como uma caixa de ponta de micropipeta, esfregue o parafilme nos poços para perfurar o parafilme as aberturas de poços e criar uma vedação ao longo do resto da placa. Remova os círculos perfuradas de parafilm agora cobre as cavidades. A placa deve agora ser firmemente coberto com filme plástico em todas as áreas, exceto o bem openings. </li></ol></li><li> 10 minutos antes do final da incubação, adicionar 200 uL de NaOH 3 N a cada poço da placa de papel de filtro, certificando-se o papel de filtro absorve o líquido todo. <ol><li> Opcionalmente antes da congelação, a transferência do médio para uma nova placa de 24 poços. Após lavagem uma vez com PBS, lisar as células remanescentes em HCl 0,1 N e calcular o teor de proteína por ensaio BCA. </li></ol></li><li> No final da incubação, snap-congelar a placa de ensaio em azoto líquido. Tenha cuidado para garantir que cada poço está completamente congelado antes de prosseguir. </li><li> Adicionar 100 ul de ácido perclórico a 70% a cada poço da placa de ensaio. Cubra imediatamente com a Placa de filtro de papel. Coloque as placas num agitador orbital e rock na velocidade orbital de 80 rpm à temperatura ambiente durante 2 horas. </li><li> Após a incubação, processar as amostras: <ol><li> Para medir a fracção de CO 2, transferir os quadrados de papel de filtro para 4 ml de fluido de cintilação líquida num cintilaçãofrasco e medida 14 do sinal C. </li><li> Para medir o material solúvel em ácido, transferir 400 ul de meio para um tubo de microcentrífuga de 1,5 ml. Centrifugar a velocidade máxima para 10 min. Adiciona-se 100 ul do sobrenadante resultante a 500 mL de 2: 1 de clorofórmio-metanol (v / v), e agitar com vortex brevemente. <ol><li> Adicionar 250 mL de água à mistura, e novamente vórtice. Centrifugar as amostras durante 10 min a 3.000 x g. Transferir 200 ul da fase superior a 4 ml de fluido de cintilação líquida num frasco de cintilação de 14 e medir o sinal C. </li></ol></li></ol></li></ol> 4. Lipogênese Assay <ol><li> A noite antes de iniciar o ensaio, lavar as células 2 vezes com PBS quente. Alterar os hepatócitos ao soro fome Médio com 100 nM de insulina. Incubar durante a noite a 37 ° C. Nota: Por causa de soro fetal bovino contém uma concentração desconhecida de hormônios metabólicos (por exemplo, insulina, glucagon), Soro de morrer de fome as células para remover quaisquer efeitos de confusão que isso pode ter sobre o ensaio. As células são viáveis ​​em soro fome Médio para&gt; 24 hr. A insulina é usada neste ensaio para estimular a lipogénese. </li><li> Faça Lipogênese Médio: Soro Fome médio com 100 nM de insulina, 10 ï¿½ de etilo frio e 0,5 uCi de 3 H-Acetato por poço. Mudar para células Lipogênese Médio e incubar a 37 ° C durante 2 horas. Inclui quaisquer compostos de interesse a ser testado. </li><li> Após o período de incubação, lavar as células 2 vezes com PBS. Lisar as células por raspagem em 120 ul de 0,1 N de HCl. Reserva de 10 uL para o ensaio de proteína (por avaliar ensaio BCA), e transferência de 100 uL para tubos de microcentrífuga de 1,5 ml. </li><li> Extrair lípidos pela adição de 500 ul de 2: 1 de clorofórmio-metanol (v / v). Vortex brevemente e incubar à TA durante 5 min. Adicionar 250 uL de água, vortex e incubar à temperatura ambiente durante um adicional de 5 min. Centrifugar as amostras 10 min a 3000 xg, RT. Cuidadosamentetransferência de fase inferior a 4 ml de fluido de cintilação líquida num frasco de cintilação e medir a actividade de 3 h. </li></ol>

<ol>
	<li>Clark, J. M., Brancati, F. L., Diehl, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+prevalence+and+etiology+of+elevated+aminotransferase+levels+in+the+United+States.">The prevalence and etiology of elevated aminotransferase levels in the United States.</a> The American journal of gastroenterology. 98, 960-967 (2003).</li><li>Lazo, 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=Prevalence+of+nonalcoholic+Fatty+liver+disease+in+the+United+States:+the+third+national+health+and+nutrition+examination+survey,+1988-1994.">Prevalence of nonalcoholic Fatty liver disease in the United States: the third national health and nutrition examination survey, 1988-1994.</a> American journal of epidemiology. 178, 38-45 (2013).</li><li>Angulo, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonalcoholic+fatty+liver+disease.">Nonalcoholic fatty liver disease.</a> The New England journal of medicine. 346, 1221-1231 (2002).</li><li>Adams, L. A., 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=The+natural+history+of+nonalcoholic+fatty+liver+disease:+a+population-based+cohort+study.">The natural history of nonalcoholic fatty liver disease: a population-based cohort study.</a> Gastroenterology. 129, 113-121 (2005).</li><li>Feldstein, A. E., 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=Hepatocyte+apoptosis+and+fas+expression+are+prominent+features+of+human+nonalcoholic+steatohepatitis.">Hepatocyte apoptosis and fas expression are prominent features of human nonalcoholic steatohepatitis.</a> Gastroenterology. 125, 437-443 (2003).</li><li>Day, C. P., James, O. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Steatohepatitis:+a+tale+of+two+'hits'.">Steatohepatitis: a tale of two 'hits'.</a> Gastroenterology. 114, 842-845 (1998).</li><li>Donnelly, K. L., 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=Sources+of+fatty+acids+stored+in+liver+and+secreted+via+lipoproteins+in+patients+with+nonalcoholic+fatty+liver+disease.">Sources of fatty acids stored in liver and secreted via lipoproteins in patients with nonalcoholic fatty liver disease.</a> The Journal of clinical investigation. 115, 1343-1351 (2005).</li><li>Lambert, J. E., Ramos-Roman, M. A., Browning, J. D., Parks, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+de+novo+lipogenesis+is+a+distinct+characteristic+of+individuals+with+nonalcoholic+fatty+liver+disease.">Increased de novo lipogenesis is a distinct characteristic of individuals with nonalcoholic fatty liver disease.</a> Gastroenterology. 146, 726-735 (2014).</li><li>Parks, E. J., Hellerstein, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thematic+review+series:+patient-oriented+research.+Recent+advances+in+liver+triacylglycerol+and+fatty+acid+metabolism+using+stable+isotope+labeling+techniques.">Thematic review series: patient-oriented research. Recent advances in liver triacylglycerol and fatty acid metabolism using stable isotope labeling techniques.</a> Journal of lipid research. 47, 1651-1660 (2006).</li><li>Befroy, D. E., 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=Direct+assessment+of+hepatic+mitochondrial+oxidative+and+anaplerotic+fluxes+in+humans+using+dynamic+13C+magnetic+resonance+spectroscopy.">Direct assessment of hepatic mitochondrial oxidative and anaplerotic fluxes in humans using dynamic 13C magnetic resonance spectroscopy.</a> Nature medicine. 20, 98-102 (2014).</li><li>Goncalves, L. A., Vigario, A. M., Penha-Goncalves, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+isolation+of+murine+hepatocytes+for+in+vitro+malaria+liver+stage+studies.">Improved isolation of murine hepatocytes for in vitro malaria liver stage studies.</a> Malaria journal. 6, 169 (2007).</li></ol>

The authors indicate they have no conflicts of interest.

O tempo de sacrifício para perfusão deve ser inferior a 3 minutos para perfusão ideal e digestão com colagenase do fígado. Uma vez que a perfusão com Perfusão Médio é iniciada, o fígado deve imediatamente alterar a aparência do vermelho ao pálido. Após aproximadamente 10 minutos de incubação com LDM, o fígado aparece inchado e rosa. No caso em que a perfusão é insuficiente, o fígado podem não exibir estas mudanças, e este será normalmente resultam num rendimento mais baixa de hepatócitos. <p c...

Non-alcoholic fatty liver disease is one of the leading causes of liver disease in Westernized cultures1,2. Lipid accumulation within the liver is associated with cell death, fibrosis, and liver failure via yet unknown mechanisms3-6. In fatty liver disease, hepatocyte-mediated &#946;-fatty acid oxidation and de novo lipogenesis are important determinants of net lipid accumulation7,8. This article will, therefore, focus on hepatocyte isolation, followed by quantification of &#946;-fatty acid oxidation and de novo lipogenesis.
Numerous methodologies have been developed to interrogate hepatocyte lipid metabolism. Though it is possible to measure metabolism of fat in vivo using stable isotopes9,10, these methods are costly, and require large numbers of animals. Additionally, the ability to investigate the effect of exogenous chemicals is limited due to the nature of in vivo experimentation. In contrast, the isolation of primary hepatocytes from mouse liver provides an affordable avenue to pursue11. Furthermore, studying hepatocytes in culture allows investigators to study the effects of varying chemicals on lipid processing while circumventing the difficulties of in vivo experimentation. Finally, isolated hepatocytes avoid any confounding from varying genetics since they are derived from the liver of a single animal.
Here we isolate and culture of hepatocytes, and we measure &#946;-fatty acid oxidation and de novo lipogenesis, using radiolabeled palmitate. The protocol detailed below is straight forward, effective, and reproducible.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Liver Perfusion Medium</td>
			<td>Life Technologies</td>
			<td>17701038</td>
			<td></td>
		</tr>
		<tr>
			<td>Liver Digest Medium</td>
			<td>Life Technologies</td>
			<td>17703034</td>
			<td>Aliquot and store at -20 &#176;C</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Corning</td>
			<td>21-040-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>10X DPBS</td>
			<td>Corning</td>
			<td>46-013-CM</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Corning</td>
			<td>10-017-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Life Technologies</td>
			<td>26140079&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagen</td>
			<td>Life Technologies</td>
			<td>A1048301&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Colloidal silica coated with polyvinylpyrrolidone</td>
			<td>GE Life Sciences</td>
			<td>17-0891-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Pyruvate</td>
			<td>Cellgro</td>
			<td>25-000-CI</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin / Streptomycin</td>
			<td>Cellgro</td>
			<td>30-001-CI</td>
			<td></td>
		</tr>
		<tr>
			<td>Insulin</td>
			<td>Sigma</td>
			<td>I0516-5ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Dexamethasone</td>
			<td>Sigma</td>
			<td>D2915-100MG</td>
			<td></td>
		</tr>
		<tr>
			<td>Albumin (BSA), Fraction V</td>
			<td>MP Biomedicals</td>
			<td>103703</td>
			<td></td>
		</tr>
		<tr>
			<td>24-Well Culture Dish</td>
			<td>Corning Falcon</td>
			<td>353047&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Tygon S3 Tubing&#160;</td>
			<td>Cole Parmer</td>
			<td>06460-34</td>
			<td></td>
		</tr>
		<tr>
			<td>Male Leur Lock to 200 Barb Connectors</td>
			<td>Cole Parmer</td>
			<td>45518-00</td>
			<td></td>
		</tr>
		<tr>
			<td>24G x 3/4&#34; Catheter</td>
			<td>SurFlo</td>
			<td>SROX2419CA</td>
			<td></td>
		</tr>
		<tr>
			<td>Perma-Hand Silk Suture</td>
			<td>Ethicon</td>
			<td>683G</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Strainer</td>
			<td>Corning Falcon</td>
			<td>08-771-2</td>
			<td></td>
		</tr>
		<tr>
			<td>IsoTemp 3013HD Recirculating Water Bath</td>
			<td>Fisher</td>
			<td>13-874-3</td>
			<td></td>
		</tr>
		<tr>
			<td>MasterFlex C/L Peristaltic Pump</td>
			<td>MasterFlex</td>
			<td>HV-77122-24</td>
			<td></td>
		</tr>
		<tr>
			<td>Microclamp</td>
			<td>Roboz</td>
			<td>RS-7438</td>
			<td>Pre-sterilize in autoclave</td>
		</tr>
		<tr>
			<td>5&#8221; Straight, Blunt-Blunt Operating Scissors</td>
			<td>Roboz</td>
			<td>RS-6810</td>
			<td>Pre-sterilize in autoclave</td>
		</tr>
		<tr>
			<td>24mm Blade Straight, Sharp-point Microdissecting Scissors</td>
			<td>Roboz</td>
			<td>RS-5912</td>
			<td>Pre-sterilize in autoclave</td>
		</tr>
		<tr>
			<td>4&#8221; 0.8mm Tip Microdissecting Forceps</td>
			<td>Roboz</td>
			<td>RS-5130</td>
			<td>Pre-sterilize in autoclave</td>
		</tr>
		<tr>
			<td>4&#8221; 0.8mm Tip Full Curve Microdissecting Forceps</td>
			<td>Roboz</td>
			<td>RS-5137</td>
			<td>Pre-sterilize in autoclave</td>
		</tr>
		<tr>
			<td>60 mL Syringe</td>
			<td>Becton Dickinson</td>
			<td>309653</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mL conical tubes</td>
			<td>Corning Falcon</td>
			<td>352070</td>
			<td></td>
		</tr>
		<tr>
			<td>BCA Protein Assay</td>
			<td>Thermo Scientific</td>
			<td>23225</td>
			<td></td>
		</tr>
		<tr>
			<td>Biosafety Cabinet</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>CO2 Incubator</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Serological pipets</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1000, 200, 20 &#956;L pipet and tips</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

determination of fatty acid oxidation and lipogenesis in mouse primary hepatocytes

Lipid metabolism in liver is complex. In addition to importing and exporting lipid via lipoproteins, hepatocytes can oxidize lipid via fatty acid oxidation, or alternatively, synthesize new lipid via de novo lipogenesis. The net sum of these pathways is dictated by a number of factors, which in certain disease states leads to fatty liver disease. Excess hepatic lipid accumulation is associated with whole body insulin resistance and coronary heart disease. Tools to study lipid metabolism in hepatocytes are useful to understand the role of hepatic lipid metabolism in certain metabolic disorders.
In the liver, hepatocytes regulate the breakdown and synthesis of fatty acids via &#946;-fatty oxidation and de novo lipogenesis, respectively. Quantifying metabolism in these pathways provides insight into hepatic lipid handling. Unlike in vitro quantification, using primary hepatocytes, making measurements in vivo is technically challenging and resource intensive. Hence, quantifying &#946;-fatty acid oxidation and de novo lipogenesis in cultured mouse hepatocytes provides a straight forward method to assess hepatocyte lipid handling. 
Here we describe a method for the isolation of primary mouse hepatocytes, and we demonstrate quantification of &#946;-fatty acid oxidation and de novo lipogenesis, using radiolabeled substrates.

Isolamentos de hepatócitos normalmente resultam em 1 - 3 x 10 7 células totais. Após incubação durante a noite, as células aparece hexagonal, muitos dos quais serão binucleadas (Figura 2). As células saudáveis ​​deve ser desprovido de granulações ou bolhas, que são indicativas de morte celular. Em geral, o ensaio de oxidação de ácido gordo é executado em três a quatro réplicas por composto de teste. Conta para o CO 2 amostras são ...

Watch this Scientific Journal Video about Determination of Fatty Acid Oxidation and Lipogenesis in Mouse Primary Hepatocytes at JoVE.com

Determination of Fatty Acid Oxidation and Lipogenesis in Mouse Primary Hepatocytes

De novo a lipogênese e oxidação do ácido β-gordo constituem vias metabólicas importantes em hepatócitos, caminhos que são perturbados em vários distúrbios metabólicos, incluindo a doença de fígado gordo. Aqui demonstramos isolamento de hepatócitos primários de rato e descrever quantificação da oxidação de ácidos graxos e β-lipogênese.

Determinação da oxidação de ácidos gordos e Lipogênese em Rato Os hepatócitos primária

Lipid metabolism in liver is complex. In addition to importing and exporting lipid via lipoproteins, hepatocytes can oxidize lipid via fatty acid ...

determination-fatty-acid-oxidation-lipogenesis-mouse-primary

Research

JoVE Journal

Biology

20.1K visualizações.  University of Massachusetts Medical School.  De novo a lipogênese e oxidação do ácido β-gordo constituem vias metabólicas importantes em hepatócitos, caminhos que são perturbados em vários distúrbios metabólicos, incluindo a doença de fígado gordo. Aqui demonstramos isolamento de hepatócitos primários de rato e descrever quantificação da oxidação de ácidos graxos e β-lipogênese. 

Vídeo: Determination of Fatty Acid Oxidation and Lipogenesis in Mouse Primary Hepatocytes

Quantitative Phosphoproteomics in Fatty Acid Stimulated Saccharomyces cerevisiae

This protocol describes the growth and stimulation, with the fatty acid oleate, of isotopically heavy and light S. cerevisiae cells. Cells are ground using a cryolysis procedure in a ball mill grinder and the resulting grindate brought into solution by urea solubilization. This procedure allows for the lysis of the cells in a metabolically inactive state, preserving phosphorylation and preventing reorientation of the phosphoproteome during cell lysis.  Following reduction, alkylation, trypsin digestion of the proteins, the samples are desalted on C18 columns and the sample complexity reduced by fractionation using hydrophilic interaction chromatography (HILIC). HILIC columns preferentially retain hydrophilic molecules which is well suited for phosphoproteomics.  Phosphorylated peptides tend to elute later in the chromatographic profile than the non phosphorylated counterparts. After fractionation, phosphopeptides are enriched using immobilized metal chromatography, which relies on charge-based affinities for phosphopeptide enrichment. At the end of this procedure the samples are ready to be quantitatively analyzed by mass spectrometry.

Quantitative Phosphoproteomics in Fatty Acid Stimulated Saccharomyces cerevisiae

Description of a quantitative phosphorylation procedure using cryolysis, urea solubilziation, HILIC fractionation and IMAC enrichment of phosphorylated peptides.

Phosphoproteomics quantitativa em ácidos graxos estimulada Saccharomyces cerevisiae</em

This protocol describes the growth and stimulation, with the fatty acid oleate, of isotopically heavy and light S. cerevisiae cells. Cells are ground ...

Biologia

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

In vivo de imagens e tratamentos terapêuticos em um modelo de camundongo ortotópico de câncer de ovário

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

GC-based Detection of Aldononitrile Acetate Derivatized Glucosamine and Muramic Acid for Microbial Residue Determination in Soil

Quantitative approaches to characterizing microorganisms are crucial for a broader understanding of the microbial status and function within ecosystems. Current strategies for microbial analysis include both traditional laboratory culture-dependent techniques and those based on direct extraction and determination of certain biomarkers1, 2. Few among the diversity of microbial species inhabiting soil can be cultured, so culture-dependent methods introduce significant biases, a limitation absent in biomarker analysis.
The glucosamine, mannosamine, galactosamine and muramic acid have been well served as measures of both the living and dead microbial mass, of these the glucosamine (most abundant) and muramic acid (uniquely from bacterial cell) are most important constituents in the soil systems3, 4. However, the lack of knowledge on the analysis restricts the wide popularization among scientific peers. Among all existing analytical methods, derivatization to aldononitrile acetates followed by GC-based analysis has emerged as a good option with respect to optimally balancing precision, sensitivity, simplicity, good chromatographic separation, and stability upon sample storage5.
Here, we present a detailed protocol for a reliable and relatively simple analysis of glucosamine and muramic acid from soil after their conversion to aldononitrile acetates. The protocol mainly comprises four steps: acid digestion, sample purification, derivatization and GC determination. The step-by-step procedure is modified according to former publications6, 7. In addition, we present a strategy to structurally validate the molecular ion of the derivative and its ion fragments formed upon electron ionization. We applied GC-EI-MS-SIM, LC-ESI-TOF-MS and isotopically labeled reagents to determine the molecular weight of aldononitrile acetate derivatized glucosamine and muramic acid; we used the mass shift of isotope-labeled derivatives in the ion spectrum to investigate ion fragments of each derivatives8. In addition to the theoretical elucidation, the validation of molecular ion of the derivative and its ion fragments will be useful to researchers using &delta;13C or ion fragments of these biomarkers in biogeochemical studies9, 10.

We describe a method protocol for the GC-based analysis of the aldonitrile acetate derivatives of glucosamine and muramic acid extracted from soil. For elucidation of the chemical mechanism, we also present a strategy to confirm the structure of the derivative and the ion fragments formed upon electron ionization.

GC baseado em detecção de ácido Aldononitrile Glucosamina e Murâmicos Acetato derivatizados à determinação do resíduo microbiana em solo

Quantitative approaches to characterizing microorganisms are crucial for a broader understanding of the microbial status and function within ecosystems. ...

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 ...

Application of Retinoic Acid to Obtain Osteocytes Cultures from Primary Mouse Osteoblasts

The need for osteocyte cultures is well known to the community of bone researchers; isolation of primary osteocytes is difficult and produces low cell numbers. Therefore, the most widely used cellular system is the osteocyte-like MLO-Y4 cell line.
The method here described refers to the use of retinoic acid to generate a homogeneous population of ramified cells with morphological and molecular osteocyte features.
After isolation of osteoblasts from mouse calvaria, all-trans retinoic acid (ATRA) is added to cell medium, and cell monitoring is conducted daily under an inverted microscope. First morphological changes are detectable after 2 days of treatment and differentiation is generally complete in 5 days, with progressive development of dendrites, loss of the ability to produce extracellular matrix, down-regulation of osteoblast markers and up-regulation of osteocyte-specific molecules.
Daily cell monitoring is needed because of the inherent variability of primary cells, and the protocol can be adapted with minimal variation to cells obtained from different mouse strains and applied to transgenic models. 
The method is easy to perform and does not require special instrumentation, it is highly reproducible, and rapidly generates a mature osteocyte population in complete absence of extracellular matrix, allowing the use of these cells for unlimited biological applications.

Treatment of primary mouse osteoblasts with retinoic acid produces a homogeneous population of ramified cells bearing morphological and molecular features of osteocytes. The method overcomes the difficulty of obtaining and maintaining primary osteocytes in culture, and can be advantageous to study cells derived from transgenic models.&#160;

A aplicação de ácido retinóico para obter culturas de osteócitos principal do mouse osteoblastos

The need for osteocyte cultures is well known to the community of bone researchers; isolation of primary osteocytes is difficult and produces low cell ...

Protocol for Isolation of Primary Human Hepatocytes and Corresponding Major Populations of Non-parenchymal Liver Cells

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic Stellate cells (HSC). Two-dimensional (2D) culture of primary human hepatocyte (PHH) is still considered as the &#34;gold standard&#34; for in vitro testing of drug metabolism and hepatotoxicity. It is well-known that the 2D monoculture of PHH suffers from dedifferentiation and loss of function. Recently it was shown that hepatic NPC play a central role in liver (patho-) physiology and the maintenance of PHH functions. Current research focuses on the reconstruction of in vivo tissue architecture by 3D- and co-culture models to overcome the limitations of 2D monocultures. Previously we published a method to isolate human liver cells and investigated the suitability of these cells for their use in cell cultures in Experimental Biology and Medicine1. Based on the broad interest in this technique the aim of this article was to provide a more detailed protocol for the liver cell isolation process including a video, which will allow an easy reproduction of this technique.
Human liver cells were isolated from human liver tissue samples of surgical interventions by a two-step EGTA/collagenase P perfusion technique. PHH were separated from the NPC by an initial centrifugation at 50 x g. Density gradient centrifugation steps were used for removal of dead cells. Individual liver cell populations were isolated from the enriched NPC fraction using specific cell properties and cell sorting procedures. Beside the PHH isolation we were able to separate KC, LEC and HSC for further cultivation.
Taken together, the presented protocol allows the isolation of PHH and NPC in high quality and quantity from one donor tissue sample. The access to purified liver cell populations could allow the creation of in vivo like human liver models.

A technique to isolate human hepatocytes and non-parenchymal liver cells from the same donor is described. The different liver cell types build the basis for functional liver models and tissue engineering. This new method aims to isolate liver cells in a high yield and viability.

Protocolo para o isolamento de hepatócitos humanos primários e Correspondente principais populações de células do fígado não-parenquimatosas

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic ...

Methods for the Determination of Rates of Glucose and Fatty Acid Oxidation in the Isolated Working Rat Heart

The mammalian heart is a major consumer of ATP and requires a constant supply of energy substrates for contraction. Not surprisingly, alterations of myocardial metabolism have been linked to the development of contractile dysfunction and heart failure. Therefore, unraveling the link between metabolism and contraction should shed light on some of the mechanisms governing cardiac adaptation or maladaptation in disease states. The isolated working rat heart preparation can be used to follow, simultaneously and in real time, cardiac contractile function and flux of energy providing substrates into oxidative metabolic pathways. The present protocol aims to provide a detailed description of the methods used in the preparation and utilization of buffers for the quantitative measurement of the rates of oxidation for glucose and fatty acids, the main energy providing substrates of the heart. The methods used for sample analysis and data interpretation are also discussed. In brief, the technique is based on the supply of 14C- radiolabeled glucose and a 3H- radiolabeled long-chain fatty acid to an ex vivo beating heart via normothermic crystalloid perfusion. 14CO2 and 3H2O, end byproducts of the enzymatic reactions involved in the utilization of these energy providing substrates, are then quantitatively recovered from the coronary effluent. With knowledge of the specific activity of the radiolabeled substrates used, it is then possible to individually quantitate the flux of glucose and fatty acid in the oxidation pathways. Contractile function of the isolated heart can be determined in parallel with the appropriate recording equipment and directly correlated to metabolic flux values. The technique is extremely useful to study the metabolism/contraction relationship in response to various stress conditions such as alterations in pre and after load and ischemia, a drug or a circulating factor, or following the alteration in the expression of a gene product.

The following protocol describes the preparation and utilization of buffers for the quantitative measurement of rates of glucose and fatty acid oxidation in the isolated working rat heart. The methods used for sample analysis and data interpretation are also discussed.

Os métodos para a determinação das taxas de glicose e ácido gordo oxidação no coração isolado de rato de Trabalho

The mammalian heart is a major consumer of ATP and requires a constant supply of energy substrates for contraction. Not surprisingly, alterations of ...

Isolation and Culture of Primary Mouse Keratinocytes from Neonatal and Adult Mouse Skin

The keratinocyte (KC) is the predominant cell type in the epidermis, the outermost layer of the skin. Epidermal KCs play a critical role in providing skin defense by forming an intact skin barrier against environmental insults, such as UVB irradiation or pathogens, and also by initiating an inflammatory response upon those insults. Here we describe methods to isolate KCs from neonatal mouse skin and from adult mouse tail skin. We also describe culturing conditions using defined growth supplements (dGS) in comparison to chelexed fetal bovine serum (cFBS). Functionally, we show that both neonatal and adult KCs are highly responsive to high calcium-induced terminal differentiation, tight junction formation and stratification. Additionally, cultured adult KCs are susceptible to UVB-triggered cell death and can release large amounts of TNF upon UVB irradiation. Together, the methods described here will be useful to researchers for the setup of in vitro models to study epidermal biology in the neonatal mouse and/or the adult mouse.

Epidermal keratinocytes form a functional skin barrier and are positioned at the front line of host defense against external environmental insults. Here we describe methods for isolation and primary culture of epidermal keratinocytes from neonatal and adult mouse skin, and induction of terminal differentiation and UVB-triggered inflammatory response from keratinocytes.

Isolamento e Cultura de Queratinócitos de Rato Primário de Pele de Rato Neonatal e Adulto

The keratinocyte (KC) is the predominant cell type in the epidermis, the outermost layer of the skin. Epidermal KCs play a critical role in providing skin ...

Isolation and 3D Collagen Sandwich Culture of Primary Mouse Hepatocytes to Study the Role of Cytoskeleton in Bile Canalicular Formation In Vitro

Hepatocytes are the central cells of the liver responsible for its metabolic function. As such, they form a uniquely polarized epithelium, in which two or more hepatocytes contribute apical membranes to form a bile canalicular network through which bile is secreted. Hepatocyte polarization is essential for correct canalicular formation and depends on interactions between the hepatocyte cytoskeleton, cell-cell contacts, and the extracellular matrix. In vitro studies of hepatocyte cytoskeleton involvement in canaliculi formation and its response to pathological situations are handicapped by the lack of cell culture, which would closely resemble the canaliculi network structure in vivo. Described here is a protocol for the isolation of mouse hepatocytes from the adult mouse liver using a modified collagenase perfusion technique. Also described is the production of culture in a 3D collagen sandwich setting, which is used for immunolabeling of cytoskeletal components to study bile canalicular formation and its response to treatments in vitro. It is shown that hepatocyte 3D collagen sandwich cultures respond to treatments with toxins (ethanol) or actin cytoskeleton altering drugs (e.g., blebbistatin) and serve as a valuable tool for in vitro studies of bile canaliculi formation and function.

Presented here is a protocol for the isolation of mouse hepatocytes from adult mouse livers using a modified collagenase perfusion technique. Also described is the long-term culture of hepatocytes in a 3D collagen sandwich setting as well as immunolabeling of the cytoskeletal components to study bile canalicular formation and its response to treatment.

Isolamento e cultura sanduíche de colágeno 3D de hepatócitos de camundongos primários para estudar o papel do citoesqueleto na formação bile canalicular in vitro

Hepatocytes are the central cells of the liver responsible for its metabolic function. As such, they form a uniquely polarized epithelium, in which two or ...

Isolation of Primary Rat Hepatocytes with Multiparameter Perfusion Control

Primary hepatocytes are widely used in basic research on liver diseases and for toxicity testing in vitro. The two-step collagenase perfusion procedure for primary hepatocyte isolation is technically challenging, especially in portal vein cannulation. The procedure is also prone to occasional contamination and variations in perfusion conditions due to difficulties in the assembly, optimization, or maintenance of the perfusion setup. Here, a detailed protocol for an improved two-step collagenase perfusion procedure with multiparameter perfusion control is presented. Primary rat hepatocytes were successfully and reliably isolated by taking the necessary technical precautions at critical steps of the procedure, and by reducing the operational difficulty and mitigating the variability of perfusion parameters through the adoption of a special intravenous catheter, standardized sterile disposable tubing, temperature control, and real-time monitoring and alarm system. The isolated primary rat hepatocytes consistently exhibit high cell viability (85%-95%), yield (2-5 x 108 cells per 200-300 g rat) and functionality (albumin, urea and CYP activity). The procedure was complemented by an integrated perfusion system, which is compact enough to be set up in the laminar flow hood to ensure aseptic operation.

This protocol details the use of a special intravenous catheter, standardized sterile disposable tubing, temperature control complemented by real-time monitoring, and an alarm system for two-step collagenase perfusion procedure to improve the consistency in the viability, yield, and functionality of isolated primary rat hepatocytes.

Isolamento de Hepatócitos Primários de Ratos com Controle de Perfusão Multiparâmetro

Primary hepatocytes are widely used in basic research on liver diseases and for toxicity testing in vitro. The two-step collagenase perfusion procedure ...