Trofoblasto humana primaria cultivo celular modelo para estudiar los efectos protectores de la melatonina contra la hipoxia / reoxigenación interrupción inducida
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 el embarazo humano, las células citotrofoblastos placentarios, que son células madre mononucleadas, rápidamente proliferan y se diferencian en cualquiera de las células citotrofoblastos vellosos o extravillous. citrofoblastos extravelloso invaden y remodelar las arterias espirales de la pared uterina. Citotrofoblastos vellosos, por el contrario, siguen proliferar, diferenciarse y se fusionan para formar sincitiotrofoblasto multinucleadas (el sincitio) 1. El mantenimiento de la homeostasis del trofoblasto velloso es esencial para el bienestar del feto y el embarazo saludable. De hecho, los trofoblastos vellosidades permiten el intercambio materno-fetal de oxígeno y nutrientes, y producen hormonas esenciales para el embarazo. Por otra parte, el sincitiotrofoblasto es el único tipo de células en contacto directo con la circulación de la sangre materna y proporciona una barrera física e inmunológica esencial. Por lo tanto, el sincitiotrofoblasto debe someterse a la apoptosis y sustitución para el mantenimiento de la homeostasis y para evIdentificación del placentaria patologías 2-5.
La técnica desarrollada por Kliman et al., 6 en 1986 para aislar citrofoblastos vellosidades primarias de placentas humanas provocó una revolución en la investigación de la placenta al permitir el estudio de los mecanismos moleculares implicados en la diferenciación del trofoblasto velloso. Esta técnica clásica, sobre la base de las digestiones enzimáticas secuenciales con tripsina y DNasa, seguido de aislamiento en los medios de densidad de centrifugación (partículas de sílice coloidal recubierto por polivinilpirrolidona, o Percoll) es ahora reconocido como el estándar de oro para el aislamiento de células del citotrofoblasto velloso. La técnica se puede optimizar mediante inmunopurificación magnético, un procedimiento que separa citotrofoblastos vellosos de las células no trofoblásticas en base a la expresión diferencial de antígenos específicos en la superficie de estas células. Elegimos el antígeno leucocitario humano ABC (HLA-ABC) debido a la ausencia de su expresión en la célula trofoblástica membrane 7,8.
La placenta es un órgano que sufre variaciones importantes en los niveles de oxígeno durante el embarazo. En el primer trimestre, la relación de la oxigenación es fisiológicamente muy baja (2% de O2), pero aumenta a niveles leves de oxigenación (8% O 2) en el segundo y tercer trimestre. Tuuli et al. 9 describe que la reproducción in vitro del medio ambiente en el interior del trofoblasto vellosidades placentarias es un desafío y las variaciones en los niveles de oxigenación pueden incluso conducir a cambios fenotípicos. Es, por lo tanto, sugiere adoptar 8% de oxígeno como normoxia para imitar la tensión de oxígeno que se encuentra en vellosidades placentarias durante el tercer trimestre de gestación 8,9. Chen et al. 10 ampliamente estudiado diversas variables relacionadas con la tensión de oxígeno en cultivos de células del trofoblasto y demostró la importancia de la determinación de los niveles de oxígeno en un ambiente pericellular. Los niveles de oxígeno en el vellosidades tienden a aumentardebido a la vasculogénesis. El flujo de sangre en las vellosidades placentarias aumenta constantemente y el nivel de peróxido de hidrógeno (una abundancia de especies reactivas del oxígeno) es una señal importante que controla la vasculogénesis 11,12. En las complicaciones del embarazo, la falta de vasculogénesis genera hipoxia, y lo más importante, las variaciones intermitentes de oxigenación (hipoxia llamados / reoxigenación). Estas condiciones llevan a un aumento anormal en el estrés oxidativo, lo que compromete la placenta y del 13,14 viabilidad fetal. Las alteraciones que se someten las células del trofoblasto in vivo durante los episodios de hipoxia / reoxigenación se pueden imitar in vitro de la siguiente manera: citrofoblastos vellosidades se mantienen en condiciones de normoxia (8% O 2) hasta que se diferencian en sincitiotrofoblasto. A continuación, se someten a condiciones de hipoxia (0,5% de O 2) para 4 horas, seguido de un 18 hr adicional de normoxia (reoxigenación). El uso de este enfoque hipoxia / reoxigenación, trofoblastos exHiBit desregulado estado redox y el aumento de los niveles de apoptosis intrínseca 8, como se ha observado en ciertas complicaciones del embarazo. Por lo tanto, este es un útil modelo in vitro para evaluar nuevos enfoques preventivos y terapéuticos para combatir las complicaciones del embarazo asociados con la placenta hipoxia / reoxigenación.
Células de la placenta producen melatonina, que tiene varias funciones importantes, tales como la capacidad de evitar el estrés oxidativo y la disfunción placentaria 15. A continuación, presentamos los modelos de aproximación y de células experimentales utilizados para demostrar el efecto protector de la melatonina en las células trofoblásticas de la placenta a nivel molecular, celular y funcional 8.
Protocol
Representative Results
Discussion
En los mamíferos, el desarrollo fetal depende directamente de la función placentaria adecuada. Los orígenes del desarrollo de trastornos de la salud se basan en la hipótesis de que la causa de las enfermedades que se manifiestan más tarde en la vida se remonta al desarrollo temprano y que la placenta tiene una función mecánica en la programación fetal 30-32. La placenta es el mediador clave de crecimiento y desarrollo del feto: regula la transferencia de nutrientes, protege contra la exposición dañi…
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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