Trophoblast primário humano Cultura celular modelo para estudar os efeitos protetores da melatonina contra a hipóxia / Disruption induzida pela reoxigenação
Summary
This manuscript presents a unique in vitro model of immunopurified human villous cytotrophoblast cells cultured under hypoxia/reoxygenation. This model is suitable to study the protective effects of promising treatments, such as melatonin, on pregnancy complications associated with increased oxidative stress and altered placental function.
Abstract
This protocol describes how villous cytotrophoblast cells are isolated from placentas at term by successive enzymatic digestions, followed by density centrifugation, media gradient isolation and immunomagnetic purification. As observed in vivo, mononucleated villous cytotrophoblast cells in primary culture differentiate into multinucleated syncytiotrophoblast cells after 72 hr. Compared to normoxia (8% O2), villous cytotrophoblast cells that undergo hypoxia/reoxygenation (0.5% / 8% O2) undergo increased oxidative stress and intrinsic apoptosis, similar to that observed in vivo in pregnancy complications such as preeclampsia, preterm birth, and intrauterine growth restriction. In this context, primary villous trophoblasts cultured under hypoxia/reoxygenation conditions represent a unique experimental system to better understand the mechanisms and signalling pathways that are altered in human placenta and facilitate the search for effective drugs that protect against certain pregnancy disorders. Human villous trophoblasts produce melatonin and express its synthesizing enzymes and receptors. Melatonin has been suggested as a treatment for preeclampsia and intrauterine growth restriction because of its protective antioxidant effects. In the primary villous cytotrophoblast cell model described in this paper, melatonin has no effect on trophoblast cells in normoxic state but restores the redox balance of syncytiotrophoblast cells disrupted by hypoxia/reoxygenation. Thus, human villous trophoblast cells in primary culture are an excellent approach to study the mechanisms behind the protective effects of melatonin on placental function during hypoxia/reoxygenation.
Introduction
Durante a gravidez humana, as células citotrofoblasto da placenta, que são células mononucleadas de haste, proliferam rapidamente e se diferenciam em células quer citotrofoblasto vilosos ou extravilosas. citotrofoblastos extravilosas invadir e remodelar as artérias em espiral da parede uterina. Citotrofoblastos viloso, por outro lado, continuar a proliferar, diferenciar-se e fundem para formar trofoblasto multinucleadas (a sincício) 1. A manutenção da homeostase trofoblasto viloso é essencial para o bem-estar fetal e gravidez saudável. Na verdade, trofoblastos vilosidades permitir a troca materno-fetal de oxigênio e nutrientes, e produzir hormônios essenciais para a gravidez. Além disso, o trofoblasto é o único tipo de célula em contacto directo com a circulação do sangue materno e proporciona uma barreira física e imunológica essencial. Portanto, o sinciciotrofoblasto deve sofrer apoptose e substituição para a manutenção da homeostase e avoid placentária patologias 2-5.
A técnica desenvolvida pela Kliman et ai. 6, em 1986, para isolar citotrofoblastos vilosidades primárias a partir de placentas humanas causou uma revolução no domínio da investigação de placenta, permitindo que o estudo dos mecanismos moleculares envolvidos na diferenciação trofoblasto viloso. Esta técnica clássica, com base em digestões enzimáticas sequenciais com tripsina e DNase, seguido pelo isolamento em meio de centrifugação de densidade (partículas de sílica coloidal revestido por polivinilpirrolidona, ou Percoll) é hoje reconhecida como o padrão de ouro para o isolamento de células citotrofoblasto vilosidades. A técnica pode ser optimizado por imunopurificação magnética, um processo que separa citotrofoblastos vilosidades a partir de células não-trofoblásticas com base na expressão diferencial de antigénios específicos nas superfícies destas células. Nós escolhemos o antigénio de leucócitos humanos ABC (HLA-ABC), devido à ausência da sua expressão na célula Membran trofoblásticae 7,8.
A placenta é um órgão que sofre variações dramáticas em níveis de oxigénio durante a gravidez. No primeiro trimestre, a relação de oxigenação é fisiologicamente muito baixa (2% de O 2), mas aumenta para níveis moderados de oxigenação (8% de O2) no segundo e terceiro trimestre. Tuuli et al. 9 descrito que a reprodução in vitro do meio ambiente trophoblast dentro das vilosidades da placenta é um desafio e variações nos níveis de oxigenação pode até levar a mudanças fenotípicas. É, por conseguinte, sugerido para adoptar 8% de oxigénio como normóxia para imitar a tensão de oxigénio encontradas em vilosidades da placenta durante o terceiro trimestre da gravidez 8,9. Chen et al. 10 extensivamente estudadas diversas variáveis relacionadas com a tensão de oxigênio em cultura de células trofoblasto e demonstrou a importância de determinar os níveis de oxigênio em um ambiente pericelular. Os níveis de oxigénio no vilosidades tendem a aumentardevido à vasculogénese. O fluxo de sangue no vilosidades aumentos placentários constantemente e o nível de peróxido de hidrogênio (uma espécie abundante reativas de oxigênio) é um sinal importante que controla vasculog�ese 11,12. Em complicações na gravidez, a falta de vasculog�ese gera hipóxia, e mais importante, as variações intermitentes de oxigenação (chamada hipóxia / reoxigenação). Estas condições levam a um aumento anormal de estresse oxidativo, o que compromete placentária e 13,14 viabilidade fetal. As alterações que se submetem a células trofoblásticas in vivo durante episódios de hipoxia / reoxigenação pode ser mimetizado in vitro, como segue: citotrofoblastos vilosidades são mantidas sob condições de normóxia (8% O 2) até que se diferenciam em trofoblasto. Elas são então submetidas a condições de hipóxia (0,5% de O2) durante 4 horas, seguido de um adicional de 18 h de normóxia (reoxigenação). Usando essa abordagem hipóxia / reoxigenação, trofoblastos exHiBit desregulada estado redox e níveis aumentados de apoptose intrínseca 8, como tem sido observada em certas complicações na gravidez. Assim, este é um útil modelo in vitro para avaliar novas abordagens terapêuticas e preventivas para combater a complicações na gravidez associados com placentária hipoxia / reoxigenação.
Células da placenta produzir melatonina, que tem várias funções importantes, tais como a capacidade de evitar o estresse oxidativo e disfunção placentária 15. Aqui, apresentamos os modelos de abordagem e de células experimentais utilizados para demonstrar os efeitos protectores da melatonina em células trofoblásticas da placenta, a nível molecular, celular e funcional 8.
Protocol
Representative Results
Discussion
Nos mamíferos, o desenvolvimento fetal é diretamente dependente da função placentária adequada. As origens do desenvolvimento de distúrbios de saúde baseiam-se na hipótese de que a causa de doenças que se manifestam mais tarde na vida pode ser rastreada até ao início do desenvolvimento e que a placenta tem um papel mecanicista na programação fetal 30-32. A placenta é o mediador chave do crescimento e desenvolvimento fetal: regula a transferência de nutrientes, protege contra as exposições pre…
Divulgations
The authors have nothing to disclose.
Acknowledgements
Supported by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC) (no. 262011-2009) to CV and March of Dimes Social and Behavioral Sciences Research grant (#12-FY12-179) to CV and JTS; by studentships to LSF from the Ministère de l’éducation, de l’Enseignement supérieurs et de la recherche (MEESR)-Fonds de recherche du Québec (FRQ)-Nature et technologies (NT) and the Fondation Universitaire Armand-Frappier INRS, to HC from the Réseau Québécois en Reproduction-NSERC-CREATE, to AAHT from the Canadian Institutes of Health Research (CIHR) and FRQ-Santé, and to JBP from NSERC; by a fellowship to EMAS from the Conselho Nacional de Desenvolvimento Cientìfico e Tecnològico (CNPq) and the Programme de bourses d’excellence pour étudiants étrangers MEESR-FRQNT.
Materials
| Curved Metzenbaum Scissors | Shandon | 9212 | surgical equipment (cell isolation) (2 units) |
| Splinter Forceps Fine 41/2in | Fisherbrand | 13-812-42 | surgical equipment (cell isolation) (2 units) |
| Scissors 4.5 Str Dissection | Fisherbrand | 08-940 | surgical equipment (cell isolation) (2 units) |
| Gauze Sponge 10cm X 10cm | Cardinal Health | 361020733 | |
| Oblong Glass Baking Dish | Pyrex | 1105397 | Glassware (2.8L) |
| Funnel Buchner | Coorstek Inc | 10-356E | Glassware (114MM DIAMeter) |
| Watch Glass | pyrex | 9985100EMD | Glassware |
| Formalin solution, neutral buffered, 10% | Sigma-Aldrich | HT501128-4L | histological tissue fixative solution |
| Trypsinizing Flasks | Wheaton | 355395 | Glassware (1 unit) |
| Disposable Culture Tubes | Kimble | 73750-13100 | Glassware |
| Borosilicate Glass Pasteur Pipet (22.8 Cm) | Fisherbrand | K63B1367820C | Glassware |
| 250 Ml Glass Beakers | Fisherbrand | KFS14005250 | Glassware |
| Glass Media Bottles With Cap | Fisherbrand | KFS14395250 | Glassware (8 units) |
| 50 Ml Corex Tube | Corning | 8422-A | (1 unit) |
| 15 Ml Polystyrene Centrifuge Tube | Corning | 430791 | |
| 50 Ml Polystyrene Centrifuge Tube | Corning | 430829 | |
| 10ml Serological Pipet | Corning | 11415038 | |
| Cell Strainer 100μm Nylon | Corning | 431752 | |
| Absorbant Liner | Scienceware | 1199918 | |
| 500 Ml Bottles Top Filter | Corning | Pore: 0,22 µm / medium and HBSS preparation | |
| 2 Ml Criogenic Vials | Corning | 430488 | |
| Freezing Container, Nalgene Mr. Frosty | Sigma-Aldrich | C1562-1EA | |
| Peristaltic Pump | Pharmacia Fine Chemicals | P3 model | |
| Shaking Water Bath | Fisher | Model 127 | |
| Vacuum Pump | ABM | 4EKFS6CX-4 | |
| Sodium Chloride | Fisherbrand | EC231-598-3 | Saline solution 0.9% |
| Hank’s Buffered Salt Solution (Hbss) | Sigma-Aldrich | H2387 | Quantity: 9.25 (one vial) for 1L of digestion solution |
| Hydroxypiperazineethansulphonic Acid (Hepes) | Life Technologies | 15630-080 | 25mL (1M) for 1L of digestion solution |
| Trypsin Type I | Sigma-Aldrich | T8003 | 9,888U |
| Deoxyribonuclease Type Iv | Roche | 10-104-159-001 | 402,000U |
| Calcium Chloride | Sigma-Aldrich | C4901 | 100mM |
| Magnesium Sulfate | Baker | 2500-01 | 800mM |
| Dulbecco’s Modified Eagle Medium High Glucose (Dmem) | Life Technologies | 10564-045 | |
| Penicillin/Streptomycin Sulphate | Hyclone | SV30010 | |
| Fetal Bovine Serum | Corning | 35-010-CV | |
| Percoll | Sigma-Aldrich | P1644 | Density centrifugation media gradient. Volume: 36mL |
| Isopropanol | Acros | 42383-0010 | 50mL |
| Dimethyl Sulfoxide | Sigma-Aldrich | 472301 | |
| Automacs Magnetic Separator | Miltenyi Biotec | Model 003 | |
| Automacs Columns | Miltenyi Biotec | 130-021-101 | |
| Automacs Running Buffer | Miltenyi Biotec | 130-091-221 | http://www.miltenyibiotec.com/~/media/Images/Products/Import/0001100/IM0001131.ashx?force=1 |
| Automacs Rinsing Solution | Miltenyi Biotec | 130-091-222 | http://www.miltenyibiotec.com/en/products-and-services/macs-cell-separation/cell-separation-buffers/automacs-rinsing-solution.aspx |
| Anti-Human Hla Abc Purified Clone W6/32 | Affymetrix eBioscience | 14-9983-82 | anti-mouse antibody |
| Anti Mouse Igg Microbeads | Miltenyi Biotec | 130048401 | |
| Multiple Well Plate - 6 Well With Lid | Corning | 3335 | Cell Bind surface |
| Multiple Well Plate - 24 Well With Lid | Corning | 3337 | Cell Bind surface |
| Multiple Well Plate - 96 Well With Lid | Corning | 3300 | Cell Bind surface |
| Modular Incubator Chamber | Billups-Rothenberg | MIC-101 | A set of two is necessary for simultaneous to generate normoxia and hypoxia/reoxygenation conditions |
| Single Flow Meter | Billups-Rothenberg | SFM3001 | |
| 50 Mm In-Line Filter | Whatman | 6721-5010 | PTFE, pore: 1.0 µm |
| Gas Regulator | Pro Star | PRS301233 | A set of two is necessary for simultaneous to generate normoxia and hypoxia/reoxygenation conditions |
| Gas Hose Class Vi Clear 5/16 | Parker | 100-05070102 | 3 pieces with ~ 0.5 m |
| 17 Mm Adjustable Gas Hose Clamp | Tiewraps | THCSS-16 | |
| Normoxia Gas Cylinder | Praxair | NI CDOXR1U-K | Size K (3rd trimester‘s composition: 5% CO2, 8% O2, Bal. N2) |
| Normoxia Gas Cylinder | Praxair | NI CDOXR1U-K | Size K (3rd trimester‘s composition: 5% CO2, 0.5% O2, Bal. N2) |
| Oxygen Microelectrode Mi-730 | Microelectrodes INC | 84477 | |
| Oxygen Adapter | Microelectrodes INC | 3572 | |
| ROS Detection Reagent: CM-H2DCFDA | Invitrogen | C-400 | |
| β-hCG ELISA kit | DRG internatinal | EIA-4115 | |
| Anti-Vimentin ourified antibody | eBioscience | 14-9897 | Host: mouse |
| Anti-Cytokeratin 7 (FITC) antibody | Abcam | ab119697 | Host: mouse |
| Alexa Fluor 488 Goat Anti-mousse IgG H&L antibody | Life Technologies | A-11029 |
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