Les lignées de cellules de la prostate sont aimablement fournies par le Dr Ling-Yu Wang et le Dr Kung Hsing-Jien au Cancer Center, UC Davis. Ce projet est soutenu par le NIH galvanotaxie subvention 4R33AI080604.

1. Culture de cellules de la prostate <ol><li> Culture les PRNS-1-1 et PNT2 prostate cellules sur des boîtes de 100 mm de la culture dans un milieu RPMI 1640 complété avec 10% de FBS et antibiotiques antimycosique à 37 ° C avec 5% de CO 2. Actualiser le milieu de culture tous les jours jusqu&#39;à ce que les cellules atteignent 80% de confluence pour les expériences de galvanotaxie. </li></ol> 2. Assemblage galvanotaxie Chambers <ol><li> Assemblage chambres inférieures <ol><li> Essuyer une chambre de galvanotaxie plastique avec du 2-propanol. Appliquer le scellant de silicium de qualité marine autour des ouvertures circulaires sur la face inférieure d&#39;une chambre avec une seringue et attacher une grande lamelle (figure 1). Utilisez le côté arrière d&#39;un applicateur de coton pour faire baisser la lamelle et essuyez l&#39;excès de colle avec des cotons-tiges. Les ouvertures circulaires permettent au milieu et le courant électrique à se écouler sur les cellules se trouvant entre les deux réservoirs intérieurs moyennes. </li><li> Couper une petite lamelle de faire 6 mm x 25 mm entretoises avec un marqueur de pointe de diamant. </li><li> Retournez la chambre. Appliquer deux bandes de colle de silicium avec une seringue et / ou une spatule en métal pour créer une surface de canal de 25 mm x 10 mm pour la fixation des cellules entre les deux ouvertures circulaires sur la vitre inférieure. Coller deux morceaux de verre entretoise entre les deux ouvertures circulaires. Utilisez le côté arrière des applicateurs de coton pour faire baisser les entretoises et essuyez l&#39;excès de colle avec des tampons et / ou des cure-dents coton. </li><li> Séchez la chambre pendant 24 heures jusqu&#39;à ce que la colle de silicium est guéri. Faire tremper pendant une nuit dans la chambre de l&#39;eau distillée pour éliminer le résidu de l&#39;acide acétique à partir de la colle. Séchez la chambre pour une utilisation immédiate, ou de stocker la chambre pour une utilisation ultérieure dans un récipient propre. <img alt="Figure 1" fo:content-width="5in" src="/files/ftp_upload/51973/51973fig1highres.jpg" width="500" /> Figure 1: Assemblée de la chambre du fond. A) Une grande lamelle est fixé sur le fond d&#39;une chambre propre. B) TDeux morceaux de cales de verre sont collées entre les deux ouvertures circulaires pour créer un canal x 25 mm 10 mm pour cellules de se fixer. </li></ol></li><li> Ensemencement de cellules sur les chambres à galvanotaxie <ol><li> Préparer le nombre de chambres de nécessiter galvanotaxie nécessaires pour l&#39;expérience. Chaque ligne ou cellule de traitement nécessite une chambre de galvanotaxie unique. Essuyer les chambres de galvanotaxie avec du 2-propanol. Laver les chambres stériles avec PBS trois fois et vérifier l&#39;écoulement de liquide entre les deux ouvertures circulaires dans les chambres. </li><li> Joindre les chambres dans des boîtes de culture de cellules stériles et les laisser se équilibrer à 37 ° C pendant 15 min. Détacher les cellules de la prostate à partir de leur boîte de culture de 5 ml en utilisant 0,25% de trypsine-EDTA à 37 ° C pendant 5 min. Neutraliser la trypsine-EDTA avec 5 ml de 10% de FBS dans du PBS. </li><li> Transférer les cellules pour tubes de 15 ml et centrifuger les cellules pendant 5 min à 200 x g, 37 ° C. Aspirer le surnageant et remettre en suspension les cellules dans 1 ml de milieu de culture. </li><li> Prenez 20 μl de solution de cellule de charge à une chambre de comptage et calculer le nombre de cellules. Ajuster la concentration cellulaire à 8 x 10 4 cellules / ml avec du milieu de culture. </li><li> Prenez les chambres de galvanotaxie de la 37 ° C incubateur. Ensemencer 350 ul de la suspension cellulaire sur chaque chambre. </li><li> Incuber les cellules pendant une nuit dans les chambres dans la boîte de culture avec Kimwipe ou humide dans une chambre d&#39;humidité à l&#39;étuve à 37 ° C avec 5% de CO 2. </li></ol></li></ol><img alt="Figure 2" fo:content-width="5in" src="/files/ftp_upload/51973/51973fig2highres.jpg" width="500" /> Figure 2:. Ensemencement des cellules à la chambre La chambre inférieure est séché et nettoyé cellules A) de la prostate sont trypsinisées, comptées et transférés dans la chambre et incubées pendant une nuit B) Une lamelle supérieure est fixée à étanchéité de la chambre avant le tournage... <ol start="3"><li> Unssembling les meilleurs chambres <ol><li> Assemblez la chambre supérieure avant le tournage. Le microscope ne peut accueillir l&#39;imagerie d&#39;une chambre de galvanotaxie seul à la fois. Réchauffez-vous 10 ml de milieu de culture à 37 ° C pour chaque chambre de galvanotaxie. Transférer une chambre de galvanotaxie des incubateurs à une plaque C de réchauffement de 37 °. </li><li> Rincer les cellules avec un milieu de culture pour éliminer les cellules seules. Donner 400 pi de milieu dans la chambre. Utilisez une seringue pour appliquer de la graisse à vide élevé au-dessus de deux cales de verre. </li><li> Ajouter une petite lamelle pour sceller la chambre. Appuyez doucement la lamelle avec le côté arrière d&#39;un applicateur de coton. Essuyez l&#39;excès du milieu avec des cotons-tiges. </li><li> Séchez la surface de verre et appliquer de la graisse à vide élevé pour sceller l&#39;écart entre la lamelle et la chambre. Utiliser une spatule en métal pour répartir la graisse. Ajouter 4 ml du milieu de culture pour les réservoirs intérieurs et vérifier l&#39;écoulement de liquide entre les réservoirs. </li></ol></li><li> Assurez-agarponts <ol><li> Couper une paire de long tuyau de PVC de 2 pouces (503/16 ID x 5/16 x 1/16 OD mur), flip et les insérer dans un bécher de 100 ml. </li><li> Mesurer 200 mg de Bacto-Agar et l&#39;ajouter à un ballon de 50 ml avec 10 ml de milieu de culture pour faire gel d&#39;agar à 2%. Micro-ondes pendant 30 secondes. Chargez le gel d&#39;agar à la tubulure en plastique avec une pipette de transfert. Laissez les ponts de gélose à la température ambiante pendant 10 minutes pour solidifier la gélose. </li><li> Ajouter 2 ml de milieu de culture dans les réservoirs extérieurs de la chambre de galvanotaxie. Insérer les ponts de gélose au milieu des réservoirs intérieur et extérieur pour conduire le courant. </li></ol></li></ol><img alt="Figure 3" fo:content-width="3.5in" src="/files/ftp_upload/51973/51973fig3highres.jpg" width="350" /> Figure 3:. Lieux les cellules de la chambre de mettre en évidence un schéma de l&#39;assemblage final de la chambre de galvanotaxie. La chambre est complètement scellé avec de la graisse à vide élevé. Medium est t ajoutéo remplir les réservoirs, et deux ponts d&#39;agar sont insérés dans la chambre. Ensuite, la chambre de galvanotaxie est transféré vers la platine du microscope et les électrodes sont fixées à appliquer le champ électrique. Vue latérale de la chambre de galvanotaxie assemblé est illustré pour démontrer que le courant électrique circule dans les cellules à travers les ponts de gélose et l&#39;espace entre le verre de protection. 3. imagerie time-lapse <ol><li> Mettre en marche l&#39;enceinte climatique à 37 ° C avec 5% de CO 2 dans l&#39;air circulant deux heures avant l&#39;imagerie. </li><li> Allumez le microscope et lancer le logiciel d&#39;image-acquisition. Calibrer la platine du microscope et sélectionnez l&#39;objectif 10X. </li><li> Transférez les chambres de galvanotaxie à la platine du microscope, sécuriser la chambre avec du ruban adhésif et de se concentrer sur les cellules. Insérer les électrodes du galvanotaxie aux réservoirs extérieurs à cathode sur le côté droit. Fixez le fil et les électrodes avec du ruban adhésif. </li><li> Allumez le bo de puissancex pour appliquer un champ électrique dans la chambre. Mesurer la tension de sortie avec le voltmètre à travers la chambre pour atteindre 2,5 volt pour la longue chambre 25 mm (100 mV / mm). Maintenir l&#39;intensité du champ au cours de l&#39;expérience en ajustant le courant de sortie. </li><li> Sélectionnez 10 points à travers la chambre de filmer dans le logiciel pour générer des dix films time-lapse. Mettre en place les conditions d&#39;acquisition à intervalles de 10 min pendant 2 heures. </li><li> Commencer à filmer et ajuster le courant de sortie en fonction des besoins. </li><li> A la fin de l&#39;expérience, retirer la chambre de la scène et fixer les cellules avec 95% d&#39;alcool. Casser la chambre avec une lame de rasoir pour nettoyer et re-utiliser. </li></ol> 4. Quantification des galvanotaxie <ol><li> Faites tourner les films de time-lapse et réorienter la cathode vers le haut des images. Exporter les films sur le logiciel de suivi de la cellule. </li><li> Suivre manuellement le (x, y) de 10 à 20 cellules à chaque point de temps de chaque film (Figure 4 A, B).Les distances de migration et les angles par rapport à la direction nord-sud, la même orientation du champ électrique, seront calculées dans le logiciel de suivi de la cellule (figure 4C). NOTE: La vitesse moyenne de migration est converti de la distance de migration totale et le temps de tournage totale. La directivité est converti à partir des angles par rapport à la valeur du cosinus. Si les cellules migrent avec directivité aléatoire, la moyenne des cosinus net sera proche de zéro. Si les cellules migrent directement vers la cathode, la valeur de cosinus sera une. Si les cellules migrer directement vers l&#39;anode, la valeur de cosinus sera -1. </li></ol><img alt="Figure 4" fo:content-width="4in" src="/files/ftp_upload/51973/51973fig4highres.jpg" width="400" /> Figure 4: Suivi de la cellule à mesurer directivité A) Superposition des lignes de repérage des images de cellules.. Les positions (x, y) des cellules sont manually suivis dans les films time-lapse. . Si les cellules migrent de façon aléatoire, le cosinus moyen est proche de zéro B) Cependant, si les cellules migrent vers la cathode ou l&#39;anode, la valeur du cosinus est proche de la moyenne + (cathode) ou -. (Anode) 1,0 C ) La directivité est présenté par la valeur du cosinus, qui est converti à partir des angles de migration (θ). Le cosinus (θ) est égal au rapport de la distance a (la distance de migration) à distance b (la distance projetée à la direction du champ électrique). <ol start="3"><li> Sauvegardez les mesures. Importez les données à une application de base de données pour calculer les résultats combinés. </li><li> Exporter les données combinées de vitesse de migration moyen et la valeur moyenne du cosinus à une feuille de calcul pour tracer les graphiques à barres (figure 5). </li></ol>

<ol>
	<li>Reid, B., Nuccitelli, R., Zhao, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+measurement+of+bioelectric+currents+with+a+vibrating+probe.">Non-invasive measurement of bioelectric currents with a vibrating probe.</a> Nat Protoc. 2 (3), 661-669 (2007).</li><li>Cao, 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=Endogenous+electric+currents+might+guide+rostral+migration+of+neuroblasts.">Endogenous electric currents might guide rostral migration of neuroblasts.</a> EMBO Rep. 14 (2), 184-190 (2013).</li><li>Hotary, K. B., Robinson, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endogenous+electrical+currents+and+voltage+gradients+in+Xenopus+embryos+and+the+consequences+of+their+disruption.">Endogenous electrical currents and voltage gradients in Xenopus embryos and the consequences of their disruption.</a> Dev Biol. 166 (2), 789-800 (1994).</li><li>Hotary, K. B., Robinson, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+of+a+role+for+endogenous+electrical+fields+in+chick+embryo+development.">Evidence of a role for endogenous electrical fields in chick embryo development.</a> Development. 114 (4), 985-996 (1992).</li><li>Yamashita, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electric+axon+guidance+in+embryonic+retina:+galvanotropism+revisited.">Electric axon guidance in embryonic retina: galvanotropism revisited.</a> Biochem Biophys Res Commun. 431 (2), 280-283 (2013).</li><li>Wood, M. D., Willits, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applied+electric+field+enhances+DRG+neurite+growth:+influence+of+stimulation+media,+surface+coating+and+growth+supplements.">Applied electric field enhances DRG neurite growth: influence of stimulation media, surface coating and growth supplements.</a> J Neural Eng. 6 (4), 046003 (2009).</li><li>Kucerova, R., 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+role+of+electrical+signals+in+murine+corneal+wound+re-epithelialization.">The role of electrical signals in murine corneal wound re-epithelialization.</a> J Cell Physiol. 226 (6), 1544-1553 (2011).</li><li>Sillman, A. L., Quang, D. M., Farboud, B., Fang, K. S., Nuccitelli, R., Isseroff, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+Dermal+fibroblasts+do+not+exhibit+directional+migration+on+collagen+I+in+direct-current+electric+fields+of+physiological+strength.">Human Dermal fibroblasts do not exhibit directional migration on collagen I in direct-current electric fields of physiological strength.</a> Exp Dermatol. 12 (4), 396-402 (2003).</li><li>Allen, G. M., Mogilner, A., Theriot, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophoresis+of+cellular+membrane+components+creates+the+directional+cue+guiding+keratocyte+galvanotaxis.">Electrophoresis of cellular membrane components creates the directional cue guiding keratocyte galvanotaxis.</a> Curr Biol. 23 (7), 560-568 (2013).</li><li>Nishimura, K. Y., Isseroff, R. R., Nuccitelli, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+keratinocytes+migrate+to+the+negative+pole+in+direct+current+electric+fields+comparable+to+those+measured+in+mammalian+wounds.">Human keratinocytes migrate to the negative pole in direct current electric fields comparable to those measured in mammalian wounds.</a> J Cell Sci. 109 (1), 199-207 (1996).</li><li>Farboud, B., Nuccitelli, R., Schwab, I. R., Isseroff, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DC+electric+fields+induce+rapid+directional+migration+in+cultured+human+corneal+epithelial+cells.">DC electric fields induce rapid directional migration in cultured human corneal epithelial cells.</a> Exp Eye Res. 70 (5), 667-673 (2000).</li><li>Fang, K. S., Ionides, E., Oster, G., Nuccitelli, R., Isseroff, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidermal+growth+factor+receptor+relocalization+and+kinase+activity+are+necessary+for+directional+migration+of+keratinocytes+in+DC+electric+fields.">Epidermal growth factor receptor relocalization and kinase activity are necessary for directional migration of keratinocytes in DC electric fields.</a> J Cell Sci. 112 (12), 1967-1978 (1999).</li><li>Li, J., 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=Activated+T+lymphocytes+migrate+toward+the+cathode+of+DC+electric+fields+in+microfluidic+devices.">Activated T lymphocytes migrate toward the cathode of DC electric fields in microfluidic devices.</a> Lab Chip. 11 (7), 1298-1304 (2011).</li><li>Meng, X., Arocena, M., Penninger, J., Gage, F. H., Zhao, M., Song, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PI3K+mediated+electrotaxis+of+embryonic+and+adult+neural+progenitor+cells+in+the+presence+of+growth+factors.">PI3K mediated electrotaxis of embryonic and adult neural progenitor cells in the presence of growth factors.</a> Exp Neurol. 227 (1), 210-217 (2011).</li><li>Wu, D., Ma, X., Lin, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DC+Electric+Fields+Direct+Breast+Cancer+Cell+Migration,+Induce+EGFR+Polarization,+and+Increase+the+Intracellular+Level+of+Calcium+Ions.+.">DC Electric Fields Direct Breast Cancer Cell Migration, Induce EGFR Polarization, and Increase the Intracellular Level of Calcium Ions. .</a> Cell Biochem Biophys. 67 (3), 1115-1125 (2013).</li><li>Martin-Granados, C., 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=A+role+for+PP1/NIPP1+in+steering+migration+of+human+cancer+cells.">A role for PP1/NIPP1 in steering migration of human cancer cells.</a> PLoS One. 7 (7), 40769 (2012).</li><li>Yang, H. Y., Charles, R. P., Hummler, E., Baines, D. L., Isseroff, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+epithelial+sodium+channel+mediates+the+directionality+of+galvanotaxis+in+human+keratinocytes.">The epithelial sodium channel mediates the directionality of galvanotaxis in human keratinocytes.</a> J Cell Sci. 126 (9), 1942-1951 (2013).</li><li>Zhao, 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=Electrical+signals+control+wound+healing+through+phosphatidylinositol-3-OH+kinase-gamma+and+PTEN.">Electrical signals control wound healing through phosphatidylinositol-3-OH kinase-gamma and PTEN.</a> Nature. 442 (7101), 457-460 (2006).</li><li>Shanley, L. J., Walczysko, P., Bain, M., MacEwan, D. J., Zhao, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influx+of+extracellular+Ca2++is+necessary+for+electrotaxis+in+Dictyostelium.">Influx of extracellular Ca2+ is necessary for electrotaxis in Dictyostelium.</a> J Cell Sci. 119 (22), 4741-4748 (2006).</li><li>Zhao, M., Agius-Fernandez, A., Forrester, J. V., McCaig, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directed+migration+of+corneal+epithelial+sheets+in+physiological+electric+fields.">Directed migration of corneal epithelial sheets in physiological electric fields.</a> Invest Ophthalmol Vis Sci. 37 (13), 2548-2558 (1996).</li><li>Peng, H. B., Jaffe, L. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polarization+of+fucoid+eggs+by+steady+electrical+fields.">Polarization of fucoid eggs by steady electrical fields.</a> Dev Biol. 53 (2), 277-284 (1976).</li><li>Lee, 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=Characterization+of+adult+human+prostatic+epithelial-cells+immortalized+by+polybrene-induced+DNA+transfection+with+a+plasmid+containing+an+origin-defective+sv40-genome.">Characterization of adult human prostatic epithelial-cells immortalized by polybrene-induced DNA transfection with a plasmid containing an origin-defective sv40-genome.</a> Int J Oncol. 4 (4), 821-830 (1994).</li><li>Berthon, P., Cussenot, O., Hopwood, L., Leduc, A., Maitland, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+expression+of+sv40+in+normal+human+prostatic+epithelial+and+fibroblastic+cells+-+differentiation+pattern+of+non-tumorigenic+cell-lines.">Functional expression of sv40 in normal human prostatic epithelial and fibroblastic cells - differentiation pattern of non-tumorigenic cell-lines.</a> Int J Oncol. 6 (2), 333-343 (1995).</li><li>Aurich-Costa, J., Vannier, A., Gr&#233;goire, E., Nowak, F., Cherif, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=IPM-FISH,+a+new+M-FISH+approach+using+IRS-PCR+painting+probes:+application+to+the+analysis+of+seven+human+prostate+cell+lines.">IPM-FISH, a new M-FISH approach using IRS-PCR painting probes: application to the analysis of seven human prostate cell lines.</a> Genes Chromosomes Cancer. 30 (2), 143-160 (2001).</li><li>Tyson, D. R., Inokuchi, J., Tsunoda, T., Lau, A., Ornstein, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culture+requirements+of+prostatic+epithelial+cell+lines+for+acinar+morphogenesis+and+lumen+formation+in+vitro:+role+of+extracellular+calcium.">Culture requirements of prostatic epithelial cell lines for acinar morphogenesis and lumen formation in vitro: role of extracellular calcium.</a> Prostate. 67 (15), 1601-1613 (2007).</li><li>Lang, S. H., Sharrard, R. M., Stark, M., Villette, J. M., Maitland, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prostate+epithelial+cell+lines+form+spheroids+with+evidence+of+glandular+differentiation+in+three-dimensional+Matrigel+cultures.">Prostate epithelial cell lines form spheroids with evidence of glandular differentiation in three-dimensional Matrigel cultures.</a> Br J Cancer. 85 (4), 590-599 (2001).</li><li>Babona-Pilipos, R., Popovic, M. R., Morshead, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+galvanotaxis+assay+for+analysis+of+neural+precursor+cell+migration+kinetics+in+an+externally+applied+direct+current+electric+field.">A galvanotaxis assay for analysis of neural precursor cell migration kinetics in an externally applied direct current electric field.</a> J Vis Exp. (68), (2012).</li><li>Meng, X., 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=Electric+field-controlled+directed+migration+of+neural+progenitor+cells+in+2D+and+3D+environments.">Electric field-controlled directed migration of neural progenitor cells in 2D and 3D environments.</a> J Vis Exp. (60), (2012).</li><li>Pullar, C. E., Isseroff, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+AMP+mediates+keratinocyte+directional+migration+in+an+electric+field.">Cyclic AMP mediates keratinocyte directional migration in an electric field.</a> J Cell Sci. 118 (9), 2023-2034 (2005).</li><li>Sheridan, D. M., Isseroff, R. R., Nuccitelli, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imposition+of+a+physiologic+DC+electric+field+alters+the+migratory+response+of+human+keratinocytes+on+extracellular+matrix+molecules.">Imposition of a physiologic DC electric field alters the migratory response of human keratinocytes on extracellular matrix molecules.</a> J Invest Dermatol. 106 (4), 642-646 (1996).</li><li>Feng, J. F., 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=Guided+migration+of+neural+stem+cells+derived+from+human+embryonic+stem+cells+by+an+electric+field.">Guided migration of neural stem cells derived from human embryonic stem cells by an electric field.</a> Stem Cells. 30 (2), 349-355 (2012).</li><li>Mukerjee, E. V., Isseroff, R. R., Nuccitelli, R., Collins, S. D., Smith, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microneedle+array+for+measuring+wound+generated+electric+fields.">Microneedle array for measuring wound generated electric fields.</a> Conf Proc IEEE Eng Med Biol Soc. 1, 4326-4328 (2006).</li><li>Nuccitelli, R., Nuccitelli, P., Li, C., Narsing, S., Pariser, D. M., Lui, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+electric+field+near+human+skin+wounds+declines+with+age+and+provides+a+noninvasive+indicator+of+wound+healing.">The electric field near human skin wounds declines with age and provides a noninvasive indicator of wound healing.</a> Wound Rep. and Reg. 19, 645-655 (2011).</li></ol>

The authors have nothing to disclose.

L&#39;analyse de la réponse d&#39;une cellule de galvanotaxie a été un indicateur fonctionnel important pour un grand nombre de migration cellulaire ou la croissance des processus 27, 28. Ici, nous utilisons une chambre sur mesure avec la surface de verre à film à deux lignées de cellules de la prostate. Ces lignées cellulaires ont démontré des degrés différents de galvanotaxie, et nous avons spéculé que la localisation intracellulaire ou l&#39;activation des protéines de galvanotaxie-médiation...

Les champs électriques endogènes sont détectés dans divers tissus tels que la peau, 1, 32, 33 et deux cerveau. Le champ électrique physiologique sert des fonctions biologiques spécifiques, y compris diriger le développement des embryons 3, 4, le guidage du prolongement de processus neuronaux 5, 6 et la promotion de l&#39;épithélium et la cornée plaie fermeture 1, 7. In vitro, l&#39;application d&#39;un champ électrique à courant continu à des cellules cultivées imite le champ électrique physiologique et induit la migration cellulaire directionnelle ou galvanotaxie. Galvanotaxie a été étudié dans des fibroblastes, des kératinocytes 8 9 de poisson, épithélial humain et les kératinocytes de la cornée 10 à 12, les lymphocytes 13, deux neuroblastes et les cellules progénitrices neuronales 14. Lorsqu&#39;il est exposé au champ appliqué, la majorité des cellules étudiées migrer de manière directionnelle vers l&#39;cathodique pôle (-). Cependant, plusieurs cellules cancéreuses, y compris hautement métastatiquecellules de cancer du sein humain et la lignée cellulaire de cancer de la prostate humain PC-3M, se déplacent vers le anodique pôle (+) 15, 16. Plusieurs mécanismes sont proposés à médiation galvanotaxie ou pour expliquer la capacité des cellules à détecter le champ électrique, y compris l&#39;activation récepteurs de l&#39;EGF 12, le canal sodique épithélial 17, PI3K et PTEN 18, et la libération des ions calcium 15, 19. Le mécanisme ne est pas encore entièrement compris et il est possible que de multiples voies de signalisation sont impliqués dans galvanotaxie. Procédé de galvanotaxie deux dimensions nous démontrons ici est utile pour caractériser la migration directionnelle de adhérente, cellules mobiles, que ce soit pour surveiller la migration individuelle des cellules 10, 12, 17 ou la migration d&#39;une feuille de cellules confluentes 18, 20. Cette technique est modifiée à partir de Peng et Jaffe 21 et Nishimura et al., avec 10 chambres de PVC transparent sur ​​mesure, avec coversl amovibleips permettant l&#39;extraction de cellules facile après galvanotaxie pour analyse secondaire, telles que l&#39;imagerie immuno-fluorescence. La surface de verre des chambres de galvanotaxie est optique compatible, ce qui permet le tournage à fort grossissement et avec des cellules marquées par fluorescence. Il permet également la conception expérimentale avec modification de la surface du verre, par exemple modifier le revêtement ou la surface des charges. Entretoise en une lamelle n ° sont utilisés dans les chambres afin de minimiser le flux de courant dans les cellules; par conséquent, le chauffage par effet Joule, qui est proportionnelle au carré du flux de courant, ne serait pas surchauffer les cellules pendant l&#39;expérience. Les ponts de liaison de gélose empêchent le contact direct des électrodes avec les cellules et empêchent le changement de pH du milieu ou de la concentration d&#39;ions pendant galvanotaxie. Deux lignes non-tumorigènes cellulaires prostate humaine ont été examinés pour leur réponse galvanotaxie dans cette étude. Les PRNS-1-1 22 et 23 sont à la fois PNT2 SV40 à immortalisation, les lignées cellulaires dépendantes de facteurs de croissance exprimant des marqueurs épithéliaux cytokératine 5, 8, 18 et 19 avec peu ou pas d&#39;expression de l&#39;antigène spécifique de la prostate (PSA). Les deux lignées cellulaires conservent la morphologie polygonale de cellules épithéliales normales, mais anomalie chromosomique a été observée dans le caryotype 22, 24. Bien que PRN-1-1 et PNT2 part des comportements similaires dans la plupart des expériences, elles montrent des différences dans la formation de la structure et dans acineuses galvanotaxie. Sur une matrice 3-D, Matrigel, les cellules PRN-1-1 former des structures creuses avec des lumières acineuses ressemblant à la glande prostatique normale 25 tissu. Cependant, les cellules forment des sphéroïdes solides PNT2 sans une lumière polarisée ou 26 épithélium. Les cellules PRN-1-1 démontrent également une réponse plus élevée que la galvanotactic PNT2 dans la présente étude. La corrélation entre la formation de la structure acinaire et galvanotaxie dans PRNS-1-1 suggère que les signaux galvanotactic peuvent jouer un rôle dans l&#39;organisation de la prles mouvements des tissus de la glande ostate en réponse à des champs électriques endogènes et fournit d&#39;autres caractéristiques de discriminer entre ces deux lignées cellulaires.

<table border="0" cellpadding="0" cellspacing="0" width="774">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:117px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:323px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Cells</td>
			<td style="width:117px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">pRNS-1-1 prostate cells</td>
			<td style="width:117px;"></td>
			<td style="width:119px;"></td>
			<td>Lee et. al., (1994)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PNT2 prostate cells</td>
			<td style="width:117px;">Sigma-Aldrich</td>
			<td style="width:119px;">95012613-1VL</td>
			<td>Berthon et al., (1995)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Medium and solutions</td>
			<td style="width:117px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">RPMI 1640 medium&#160;</td>
			<td style="width:117px;">Invitrogen</td>
			<td style="width:119px;">11875-093</td>
			<td>warm up to 37&#176;C before use</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Fetal Bovine Serum - Premium</td>
			<td style="width:117px;">Atlanta Biologicals</td>
			<td style="width:119px;">S11150</td>
			<td>10% in PBS, warm up to 37&#176;C before use</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Antibiotic-Antimycotic (100x)</td>
			<td style="width:117px;">Life Technologies</td>
			<td style="width:119px;">15240</td>
			<td>add 5mL to 500mL medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">2-propanol</td>
			<td style="width:117px;">VWR</td>
			<td>BDH1133-5GL</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PBS</td>
			<td style="width:117px;">-</td>
			<td style="width:119px;">-</td>
			<td>137mM NaCl, 2.7mM KCl, 4.3mM Na2HPO4 and 1.5mM KH2PO4 in 1000mL of H2O, pH to 7.4 and autoclaved, warm up to 37&#176;C before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.25% Trypsin-EDTA&#160;</td>
			<td style="width:117px;">Invitrogen</td>
			<td style="width:119px;">25200-056</td>
			<td>warm up to 37&#176;C before use, treat cells for 3-5 min at 37&#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Galvanotaxis device</td>
			<td style="width:117px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Galvanotaxis chambers</td>
			<td style="width:117px;">Precision Plastics Inc, CA</td>
			<td style="width:119px;"></td>
			<td>custom-designed (1/4&#34; X 2&#34; X 3.5&#34;), non-toxic, clear PVC chambers</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Galvanotaxis electrodes</td>
			<td style="width:117px;">UCD electric shop</td>
			<td style="width:119px;"></td>
			<td>platinum coiled electrodes with flexable cords</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Galvanotaxis power box</td>
			<td style="width:117px;">Substrate Engineering, CA</td>
			<td style="width:119px;"></td>
			<td>custom-designed DC power output with voltmeter</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Microscope Cover Glass, Large, 45X50mm-No. 1.5</td>
			<td style="width:117px;">Fisher</td>
			<td style="width:119px;">12-544-F</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Microscope Cover Glass, small, 25X25mm, No. 1</td>
			<td style="width:117px;">ThermoScientific</td>
			<td style="width:119px;">3307</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Diamond point marker</td>
			<td style="width:117px;">ThermoScientific</td>
			<td style="width:119px;">750</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Marine grade silicon sealer, clear</td>
			<td style="width:117px;">3M</td>
			<td style="width:119px;">051135-08019</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">High vacuum grease</td>
			<td style="width:117px;">Dow Corning</td>
			<td style="width:119px;">2021846-0807</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">6mL syringe</td>
			<td style="width:117px;">Fisher Scientific</td>
			<td style="width:119px;">05-561-64</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Nichiryo Syringe, 1.5mL</td>
			<td style="width:117px;">Nichiryo</td>
			<td style="width:119px;">SG-M</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Cotton applicators</td>
			<td style="width:117px;">Purtian Medical Products</td>
			<td style="width:119px;">806-WC</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Qtips</td>
			<td style="width:117px;">Johnson &#38; Johnson</td>
			<td style="width:119px;">729389</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nalgene 180 PVC tubing&#160;</td>
			<td style="width:117px;">Nalgene</td>
			<td style="width:119px;">8000-9030</td>
			<td>503/16 ID x 5/16 OD x 1/16 Wall</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bacto-Agar</td>
			<td style="width:117px;">Difco</td>
			<td style="width:119px;">0140-01</td>
			<td>make 2% agar solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Razor Blade</td>
			<td style="width:117px;">Personna</td>
			<td style="width:119px;">74-0001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Equipments and Software</td>
			<td style="width:117px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Benchtop Centrifuge</td>
			<td style="width:117px;">Eppendorf</td>
			<td style="width:119px;">5810R</td>
			<td>operated with an A-4-62 rotor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cellometer Auto T4</td>
			<td style="width:117px;">Nexcelom</td>
			<td style="width:119px;">Auto T4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Cellometer counting chambers</td>
			<td style="width:117px;">Nexcelom</td>
			<td style="width:119px;">CHT4-SD100-002</td>
			<td>load 20uL cell solutions to count</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Culture Temp Warming plate</td>
			<td style="width:117px;">Bel-Art Scienceware</td>
			<td style="width:119px;">370150000</td>
			<td>to keep the galvanotaxis chambers at 37&#176;C&#160;</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Eclipse TE-2000 microscope with motorized stage and environmental chamber</td>
			<td style="width:117px;">Nikon</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Plan Fluor 10X/0.30 objective len</td>
			<td style="width:117px;">Nikon</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Retiga EX CCD camera&#160;</td>
			<td style="width:117px;">Qimaging</td>
			<td style="width:119px;"></td>
			<td>Cooled CCD camara, mono-color, 12-bit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Compressed air with 5% CO2&#160;</td>
			<td style="width:117px;">Airgas</td>
			<td style="width:119px;"></td>
			<td>special order</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Volocity 6.3</td>
			<td style="width:117px;">PerkinElmer</td>
			<td style="width:119px;"></td>
			<td>Image acquiring software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Improvision OpenLab 5.5.2</td>
			<td style="width:117px;">PerkinElmer</td>
			<td style="width:119px;"></td>
			<td>Cell tracking software and customized to measure migration angles</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FileMaker Pro Advanced, 8.0</td>
			<td style="width:117px;">FileMaker</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microsoft Excel 2008 for Mac</td>
			<td style="width:117px;">Microsoft</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

utilizing custom-designed galvanotaxis chambers to study directional migration of prostate cells

Le champ électrique physiologique sert des fonctions biologiques spécifiques, telles que diriger la migration des cellules dans le développement embryonnaire, l&#39;excroissance neuronale et la cicatrisation epitheliale. L&#39;application d&#39;un champ électrique à courant continu à des cellules cultivées in vitro induit la migration des cellules directionnel, ou galvanotaxie. Procédé de galvanotaxie deux dimensions nous démontrons ici est modifiée avec sur mesure poly (chlorure de vinyle) (PVC) chambres, la surface de verre, des électrodes en platine et l&#39;utilisation d&#39;une platine motorisée à laquelle les cellules sont imagés. Les chambres de PVC et des électrodes de platine présentent une faible cytotoxicité et sont abordables et ré-utilisable. La surface du verre et la platine du microscope motorisée améliorer la qualité des images et permettent d&#39;éventuelles modifications de la surface du verre et des traitements aux cellules. Nous avons filmé l&#39;galvanotaxie de deux, les lignées cellulaires non-tumorigènes SV40 immortalisé la prostate, PRNS-1-1 et PNT2. Ces deux lignées cellulaires montrent des vitesses de migration à la fois similaires et migrent versla cathode, mais ils montrent un degré différent de directivité dans galvanotaxie. Les résultats obtenus par l&#39;intermédiaire de ce protocole suggérer que les PRNS-1-1 et les lignées cellulaires PNT2 peuvent avoir des caractéristiques intrinsèques qui régissent leurs réponses migrateurs directionnelles.

Deux lignes de cellules de la prostate (PRN-1-1 et PNT2) ont été étudiés avec cette méthode. Les cellules dans les deux lignes migrent à des vitesses similaires de 1,0 +/- 0,3 microns / min au cours de 2 heures (figure 5A). Cependant, la directivité du champ électrique est de 0,7 +/- 0,3-PRN pour la ligne 1-1, et 0,2 +/- 0,8 pour la ligne de PNT2 (figure 5B). Les résultats montrent une différence significative dans la galvanotaxie de ces deux lignées cellulaires (p &lt;0,01, ...

Watch this Scientific Journal Video about Utilizing Custom-designed Galvanotaxis Chambers to Study Directional Migration of Prostate Cells at JoVE.com

Utilizing Custom-designed Galvanotaxis Chambers to Study Directional Migration of Prostate Cells

We present a method to apply a physiological electric field to migrating, immortalized prostate cells in a custom-made galvanotaxis chamber. Using this method, we demonstrate that 2 lines of non-tumorigenic prostate cells demonstrate different degrees of migration directionality in the field.

Utilisant conçus sur mesure galvanotaxie Chambers à étudier directionnel migration des cellules de la prostate

The physiological electric field serves specific biological functions, such as directing cell migration in embryo development, neuronal outgrowth and ...

utilizing-custom-designed-galvanotaxis-chambers-to-study-directional

Research

JoVE Journal

Biology

9.1K vues.  University of California, Davis. We present a method to apply a physiological electric field to migrating, immortalized prostate cells in a custom-made galvanotaxis chamber. Using this method, we demonstrate that 2 lines of non-tumorigenic prostate cells demonstrate different degrees of migration directionality in the field.

Vidéo: Utilizing Custom-designed Galvanotaxis Chambers to Study Directional Migration of Prostate Cells

Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of the visual system provide more empirical evidence for functional applications. Investigation into the sensory system provides information about the sensory capacity, learning and memory ability, and establishes known baseline behaviour in which to gauge deviations (Burghardt, 1977). However, unlike mammalian or avian systems, testing for learning and memory in a reptile species is difficult. Furthermore, using an operant paradigm as a psychophysical measure of sensory ability is likewise as difficult. Historically, reptilian species have responded poorly to conditioning trials because of issues related to motivation, physiology, metabolism, and basic biological characteristics. Here, I demonstrate an operant paradigm used a novel model lizard species, the Jacky dragon (Amphibolurus muricatus) and describe how to test peripheral sensitivity to salient speed and motion characteristics. This method uses an innovative approach to assessing learning and sensory capacity in lizards. I employ the use of random-dot kinematograms (RDKs) to measure sensitivity to speed, and manipulate the level of signal strength by changing the proportion of dots moving in a coherent direction. RDKs do not represent a biologically meaningful stimulus, engages the visual system, and is a classic psychophysical tool used to measure sensitivity in humans and other animals. Here, RDKs are displayed to lizards using three video playback systems. Lizards are to select the direction (left or right) in which they perceive dots to be moving. Selection of the appropriate direction is reinforced by biologically important prey stimuli, simulated by computer-animated invertebrates.

Testing visual sensitivity in lizards using an operant conditioning paradigm that employs video playback of random-dot kinematograms and computer-generated invertebrates.

Test sensibilité visuelle à la vitesse et la direction du mouvement chez les lézards

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of ...

Recherche

Biologie

A Cell-to-cell Macromolecular Transport Assay in Planta Utilizing Biolistic Bombardment

Here, we present a simple and rapid protocol to detect and assess the extent of cell-to-cell macromolecular transport in planta. In this protocol, a fluorescently tagged-protein of interest is transiently expressed in plant tissue following biolistic delivery of its encoding DNA construct. The intra- and intercellular distribution of the tagged protein is then analyzed by confocal microscopy. We describe this technology in detail, providing step-by-step protocols to assay and evaluate the extent of symplastic protein transport in three plant species, Arabidopsis thaliana, Nicotiana benthamiana and N. tabacum (tobacco).

A Cell-to-cell Macromolecular Transport Assay in Planta Utilizing Biolistic Bombardment

Macromolecular trafficking between plant cells can be assessed by transiently expressing a fluorescently-tagged protein of interest and analyzing its intra- and intercellular distribution by confocal microscopy.

Une cellule à cellule essai de transport macromoléculaire In planta Utilisant bombardement biolistique

Here, we present a simple and rapid protocol to detect and assess the extent of cell-to-cell macromolecular transport in planta. In this protocol, a ...

Quantitative Analysis of Random Migration of Cells Using Time-lapse Video Microscopy

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion 1, 2. During directional migration, cells move rapidly in response to an extracellular chemotactic signal, or in response to intrinsic cues 3 provided by the basic motility machinery. Random migration occurs when a cell possesses low intrinsic directionality, allowing the cells to explore their local environment.
Cell migration is a complex process, in the initial response cell undergoes polarization and extends protrusions in the direction of migration 2. Traditional methods to measure migration such as the Boyden chamber migration assay is an easy method to measure chemotaxis in vitro, which allows measuring migration as an end point result. However, this approach neither allows measurement of individual migration parameters, nor does it allow to visualization of morphological changes that cell undergoes during migration.
Here, we present a method that allows us to monitor migrating cells in real time using video - time lapse microscopy. Since cell migration and invasion are hallmarks of cancer, this method will be applicable in studying cancer cell migration and invasion in vitro. Random migration of platelets has been considered as one of the parameters of platelet function 4, hence this method could also be helpful in studying platelet functions. This assay has the advantage of being rapid, reliable, reproducible, and does not require optimization of cell numbers. In order to maintain physiologically suitable conditions for cells, the microscope is equipped with CO2 supply and temperature thermostat. Cell movement is monitored by taking pictures using a camera fitted to the microscope at regular intervals. Cell migration can be calculated by measuring average speed and average displacement, which is calculated by Slidebook software.

This method allows monitoring of cells in real time and quantitative measurements of different cell migration parameters such as speed, displacement, and velocity. Unlike the traditional methods, this real time approach is not based on endpoint quantitative migration measurements; instead it allows monitoring and calculating different parameters continuously.

Analyse quantitative des migrations au hasard des cellules en utilisant la microscopie vidéo time-lapse

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion 1, 2. During ...

Preparing Individual Drosophila Egg Chambers for Live Imaging

Live cell imaging is an important technique applied to a number of Drosophila tissues used as models to investigate topics such as axis specification, cell differentiation and organogenesis 1. Correct preparation of the experimental samples is a crucial, often neglected, step. The goal of preparation is to ensure physiological relevance and to establish optimal imaging conditions. To maintain tissue viability, it is critical to avoid dehydration, hypoxia, overheating or medium deterioration 2. 
 The Drosophila egg chamber is a well established system for examining questions relating, but not limited, to body patterning, mRNA localization and cytoskeletal organization 3,4. For early- and mid-stage egg chambers, mounting in halocarbon oil is good for survival in that it allows free diffusion of oxygen, prevents dehydration and hypoxia and has superb optical properties for microscopy. Imaging of fluorescent proteins is possible through the introduction of transgenes into the egg chamber or physical injection of labeled RNA, protein or antibodies 5-7. For example, addition of MS2 constructs to the genome of animals enables real time observation of mRNAs in the oocyte 8. These constructs allow for in vivo labeling of mRNA through utilization of the MS2 bacteriophage RNA stem loop interaction with its coat protein 9. 
 Here, we present a protocol for the extraction of ovaries as well as isolating individual ovarioles and egg chambers from the female Drosophila. For a detailed description of Drosophila oogenesis see Allan C. Spradling (1993, reprinted 2009) 10.

Preparing Individual Drosophila Egg Chambers for Live Imaging

The Drosophila egg chamber is an excellent model for studying the mechanisms of mRNA localization. In order to capture the dynamic events that underpin the processes of localization, rapid high resolution imaging of live tissue is required. Here, we present a protocol for dissection and imaging of live samples with minimal disruption.

Préparation individuelle Drosophila Œuf Chambres pour l&#39;imagerie en direct

Live cell imaging is an important technique applied to a number of Drosophila tissues used as models to investigate topics such as axis specification, ...

Induction and Analysis of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is essential for proper morphogenesis during development. Misregulation of this process has been implicated as a key event in fibrosis and the progression of carcinomas to a metastatic state. Understanding the processes that underlie EMT is imperative for the early diagnosis and clinical control of these disease states. Reliable induction of EMT in vitro is a useful tool for drug discovery as well as to identify common gene expression signatures for diagnostic purposes. Here we demonstrate a straightforward method for the induction of EMT in a variety of cell types. Methods for the analysis of cells pre- and post-EMT induction by immunocytochemistry are also included. Additionally, we demonstrate the effectiveness of this method through antibody-based array analysis and migration/invasion assays.

A straightforward method is described for the induction of epithelial to mesenchymal transition (EMT) in a variety of cell types. Methods for the analysis of cells in EMT states by immunocytochemistry are included.

Induction et analyse des épithéliale à mésenchymateuses transition

Epithelial  to mesenchymal transition (EMT) is essential for proper morphogenesis during  development. Misregulation of this  process has been implicated ...

Using Caco-2 Cells to Study Lipid Transport by the Intestine

Studies of dietary fat absorption are generally conducted by using an animal model equipped with a lymph cannula. Although this animal model is widely accepted as the in vivo model of dietary fat absorption, the surgical techniques involved are challenging and expensive. Genetic manipulation of the animal model is also costly and time consuming. The alternative in vitro model is arguably more affordable, timesaving, and less challenging. Importantly, the in vitro model allows investigators to examine the enterocytes as an isolated system, reducing the complexity inherent in the whole organism model. This paper describes how human colon carcinoma cells (Caco-2) can serve as an in vitro model to study the enterocyte transport of lipids, and lipid-soluble drugs and vitamins. It explains the proper maintenance of Caco-2 cells and the preparation of their lipid mixture; and it further discusses the valuable option of using the permeable membrane system. Since differentiated Caco-2 cells are polarized, the main advantage of using the permeable membrane system is that it separates the apical from the basolateral compartment. Consequently, the lipid mixture can be added to the apical compartment while the lipoproteins can be collected from the basolateral compartment. In addition, the effectiveness of the lentivirus expression system in upregulating gene expression in Caco-2 cells is discussed. Lastly, this paper describes how to confirm the successful isolation of intestinal lipoproteins by transmission electron microscopy (TEM).

Caco-2 cells can serve as an in vitro model to study the enterocyte transport of lipids, and lipid-soluble drugs/vitamins. The permeable membrane system separates the apical from the basolateral compartment, while the lentivirus expression system offers an effective gene overexpression method. The isolation of lipoproteins is confirmed by TEM.

Utilisation de cellules Caco-2 à étudier Lipid Transport par l&#39;intestin

Studies of dietary fat absorption are generally conducted by using an animal model equipped with a lymph cannula. Although this animal model is widely ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid decline in renal function and development of the clinical syndrome known as acute kidney injury (AKI). Pharmacological agents used to treat medical circumstances ranging from bacterial infection to cancer, when administered individually or in combination with other drugs, can initiate AKI. Zebrafish are a useful animal model to study the chemical effects on renal function in vivo, as they form an embryonic kidney comprised of nephron functional units that are conserved with higher vertebrates, including humans. Further, zebrafish can be utilized to perform genetic and chemical screens, which provide opportunities to elucidate the cellular and molecular facets of AKI and develop therapeutic strategies such as the identification of nephroprotective molecules. Here, we demonstrate how microinjection into the zebrafish embryo can be utilized as a paradigm for nephrotoxin studies.

Renal injuries incurred from nephrotoxins, which include drugs ranging from antibiotics to chemotherapeutics, can result in complex disorders whose pathogenesis remains incompletely understood. This protocol demonstrates how zebrafish can be used for disease modeling of these conditions, which can be applied to the identification of renoprotective measures.

Néphrotoxine microinjection dans Zebrafish au Modèle lésion rénale aiguë

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...

Utilizing pHluorin-tagged Receptors to Monitor Subcellular Localization and Trafficking

Understanding membrane protein trafficking, assembly, and expression requires an approach that differentiates between those residing in intracellular organelles and those localized on the plasma membrane. Traditional fluorescence-based measurements lack the capability to distinguish membrane proteins residing in different organelles. Cutting edge methodologies transcend traditional methods by coupling pH-sensitive fluorophores with total internal reflection fluorescence microscopy (TIRFM). TIRF illumination excites the sample up to approximately 150 nm from the glass-sample interface, thus decreasing background, increasing the signal to noise ratio, and enhancing resolution. The excitation volume in TIRFM encompasses the plasma membrane and nearby organelles such as the peripheral ER. Superecliptic pHluorin (SEP) is a pH sensitive version of GFP. Genetically encoding SEP into the extracellular domain of a membrane protein of interest positions the fluorophore on the luminal side of the ER and in the extracellular region of the cell. SEP is fluorescent when the pH is greater than 6, but remains in an off state at lower pH values. Therefore, receptors tagged with SEP fluoresce when residing in the endoplasmic reticulum (ER) or upon insertion in the plasma membrane (PM) but not when confined to a trafficking vesicle or other organelles such as the Golgi. The extracellular pH can be adjusted to dictate the fluorescence of receptors on the plasma membrane. The difference in fluorescence between TIRF images at neutral and acidic extracellular pH for the same cell corresponds to a relative number of receptors on the plasma membrane. This allows a simultaneous measurement of intracellular and plasma membrane resident receptors. Single vesicle insertion events can also be measured when the extracellular pH is neutral, corresponding to a low pH trafficking vesicle fusing with the plasma membrane and transitioning into a fluorescent state. This versatile technique can be exploited to study localization, expression, and trafficking of membrane proteins.

Labeling the extracellular domain of a membrane protein with a pH sensitive fluorophore, superecliptic pHluorin (SEP), allows subcellular localization, expression, and trafficking to be determined. Imaging SEP-labeled proteins with total internal reflection fluorescence microscopy (TIRFM) enables the quantification of protein levels in the peripheral ER and plasma membrane.

Utilisant Receptors pHluorin-taggés pour surveiller Subcellular localisation et le trafic

Understanding membrane protein trafficking, assembly, and expression requires an approach that differentiates between those residing in intracellular ...

Imaging Intermediate Filaments and Microtubules with 2-dimensional Direct Stochastic Optical Reconstruction Microscopy

The cytoskeleton, composed of actin microfilaments, microtubules, and intermediate filaments (IF), plays a key role in the control of cell shape, polarity, and motility. The organization of the actin and microtubule networks has been extensively studied but that of IFs is not yet fully characterized. IFs have an average diameter of 10 nm and form a network extending throughout the cell cytoplasm. They are physically associated with actin and microtubules through molecular motors and cytoskeletal linkers. This tight association is at the heart of the regulatory mechanisms that ensure the coordinated regulation of the three cytoskeletal networks required for most cell functions. It is therefore crucial to visualize IFs alone and also together with each of the other cytoskeletal networks. However, IF networks are extremely dense in most cell types, especially in glial cells, which makes its resolution very difficult to achieve with standard fluorescence microscopy (lateral resolution of ~250 nm). Direct STochastic Optical Reconstruction Microscopy (dSTORM) is a technique allowing a gain in lateral resolution of one order of magnitude. Here, we show that lateral dSTORM resolution is sufficient to resolve the dense organization of the IF networks and, in particular, of IF bundles surrounding microtubules. Such tight association is likely to participate in the coordinated regulation of these two networks and may, explain how vimentin IFs template and stabilize microtubule organization as well as could influence microtubule dependent vesicular trafficking. More generally, we show how the observation of two cytoskeletal components with dual-color dSTORM technique brings new insight into their mutual interaction.

The overall goal of this methodology is to give the optimal experimental conditions from sample preparation to image acquisition and reconstruction in order to perform 2D dual color dSTORM images of microtubules and intermediate filaments in fixed cells

Imagerie des Filaments intermédiaires et Microtubules avec directes 2 dimensions de Reconstruction stochastique optiques de microscopie

The cytoskeleton, composed of actin microfilaments, microtubules, and intermediate filaments (IF), plays a key role in the control of cell shape, ...

A Proximal Culture Method to Study Paracrine Signaling Between Cells

Intercellular interactions play an important role in many biological processes, including tumor progression, immune responses, angiogenesis, and development. Paracrine or juxtacrine signaling mediates such interactions. The use of a conditioned medium and coculture studies are the most common methods to discriminate between these two types of interactions. However, the effect of localized high concentrations of secreted factors in the microenvironment during the paracrine interactions is not accurately recapitulated by conditioned medium and, thus, may lead to imprecise conclusions. To overcome this problem, we have devised a proximal culture method to study paracrine signaling. The two cell types are grown on either surface of a 10 &#181;m-thick polycarbonate membrane with 0.4 &#181;m pores. The pores allow the exchange of secreted factors and, at the same time, inhibit juxtacrine signaling. The cells can be collected and lysed at the endpoint to determine the effects of the paracrine signaling. In addition to allowing for localized concentration gradients of secreted factors, this method is amenable to experiments involving prolonged periods of culture, as well as the use of inhibitors. While we use this method to study the interactions between ovarian cancer cells and the mesothelial cells they encounter at the site of metastasis, it can be adapted to any two adherent cell types for researchers to study paracrine signaling in various fields, including tumor microenvironment, immunology, and development.

Paracrine and juxtacrine cellular interactions play an important role in many biological processes, including tumor progression, immune responses, angiogenesis, and development. Here, a proximal culture method is used to study paracrine signaling where the localized concentrations of the secreted factors are maintained while preventing direct cellular contact.