Visualisering af cellecyklus Variationer og Bestemmelse af Kimdannelse i postnatale cardiomyocytter
Summary
To distinguish cell division from cell cycle variations in cardiomyocytes, we present protocols using two transgenic mouse lines: Myh6-H2B-mCh transgenic mice, for the unequivocal identification of cardiomyocyte nuclei, and CAG-eGFP-anillin mice, for distinguishing cell division from cell cycle variations.
Abstract
Cardiomyocytes are prone to variations of the cell cycle, such as endoreduplication (continuing rounds of DNA synthesis without karyokinesis and cytokinesis) and acytokinetic mitosis (karyokinesis but no cytokinesis). Such atypical cell cycle variations result in polyploid and multinucleated cells rather than in cell division. Therefore, to determine cardiac turnover and regeneration, it is of crucial importance to correctly identify cardiomyocyte nuclei, the number of nuclei per cell, and their cell cycle status. This is especially true for the use of nuclear markers for identifying cell cycle activity, such as thymidine analogues Ki-67, PCNA, or pHH3. Here, we present methods for recognizing cardiomyocytes and their nuclearity and for determining their cell cycle activity. We use two published transgenic systems: the Myh6-H2B-mCh transgenic mouse line, for the unequivocal identification of cardiomyocyte nuclei, and the CAG-eGFP-anillin mouse line, for distinguishing cell division from cell cycle variations. Combined together, these two systems ease the study of cardiac regeneration and plasticity.
Introduction
Den korrekte identifikation af cardiomyocyte kerner og cellecyklus status er af afgørende betydning for bestemmelse af hjertemusklen omsætning og regeneration. Dette gælder især for anvendelsen af nukleare markører, såsom phh3, Ki-67, eller thymidinanaloger, til identifikation cellecyklusaktivitet. Som proliferative kapacitet voksne mammale cardiomyocytter er meget lille 1, en falsk identifikation af en kerne positiv for en proliferationsmarkør af en cardiomyocyte kerne kunne gøre en afgørende forskel i resultatet af en proliferationsassay. Desuden cardiomyocytter er tilbøjelige til variationer i cellecyklussen, såsom endoreduplikation og acytokinetic mitose, som resulterer i polyploide og flerkernede celler frem for i celledeling. Til dette formål fortolkningen af antistof-farvning mod almindelige cellecyklus markører, ikke i alle tilfælde.
Her præsenteres metoder til straight-forwa rd anerkendelse af mus cardiomyocytter og deres nuclearity i native isolerede celler og tykke vævssnit ved postnatal og voksne stadier af utvetydig identifikation af deres kerner. Til dette formål blev en transgen mus linje med cardiomyocyte-specifik ekspression af et fusionsprotein bestående af menneskelige histon H2B og mCherry under kontrol af Myh6 promotor (Myh6-H2B-MCH), der anvendes 2. Krydsbestøvning denne mus linje med en transgen proliferation indikator mus linje, hvori ekspressionen af et eGFP-anillin fusionsproteinet er under kontrol af den allestedsnærværende kylling actinpromotor med en CMV enhancer (CAG-eGFP-anillin), giver mulighed for bestemmelse af cellecyklus status. Stilladset protein anillin udtrykkes specifikt i celle-cyklus aktive celler 3, og dens differential subcellulære lokalisering under cellecyklussen muliggør levende sporing cellecyklusfremadskriden med en høj opløsning på M-faseef "> 4. Derfor er den dobbelte transgene mus kan bruges til at skelne mellem prolifererende cardiomyocytter og dem, der undergår celle-cyklus variationer. Dette beviser især nyttigt i screening for proliferationsinducerende stoffer in vitro.
Protocol
Representative Results
Discussion
Der er en uenighed om, hvorvidt cardiomyocytter er i stand til at indtaste hele cellecyklus og dele efter skade og under vævshomeostase. Værdier for den grundlæggende omsætning af cardiomyocytter har fået i området mellem 1% 1 og 80% 7. Også efter en kardiel læsion, har induktionen af cellecyklus aktivitet og fremme af nye cardiomyocytter blevet rapporteret i grænseområdet, med værdier mellem 0,0083% 8 og 25 – 40% 7.</su…
Divulgations
The authors have nothing to disclose.
Acknowledgements
We thank S. Grünberg (Bonn, Germany) and P. Freitag (Bonn, Germany) for their technical assistance.
Materials
| 10 cm petri dish | Sarstedt | 821472 | |
| 100 µm cell strainer | Becton Dickinson GmbH/Falcon | 352360 | |
| 2,3-Butanedione monoxime (BDM) | Sigma-Aldrich | B0753 | |
| G20x1 ½ injection cannula, Sterican | Braun, Melsungen | 4657519 | |
| 20 gauge needle | Becton Dickinson GmbH | 301300 | |
| 24-well plates | Becton Dickinson GmbH/Falcon | 353047 | |
| 2-Methyl-butane | Carl Roth GmbH + Co. KG | 3927.1 | |
| 37% formaldehyde solution | AppliChem GmbH | A0936,1000 | |
| 3-way stopcock | B. Braun Medical Inc. | 16494C | |
| 50 ml syringe | B. Braun Medical Inc. | 8728810F | |
| 70% ethanol | Otto Fischar GmbH | 27669 | |
| Alexa-Fluor-conjugated secondary antibody | Jackson ImmunoResearch | 115-605-205 | |
| Alpha-Aktinin EA-53, Mouse IgG | Sigma-Aldrich, Steinheim | A7811 | |
| CaCl | Sigma-Aldrich | C4901 | |
| Cell Culture Microplate, 96 Well, Half Area | Greiner bio-one | 675986 | |
| Collagenase B | Roche | 11088815001 | |
| confocal microscope Eclipse Ti-E | Nikon | ||
| cryostat CM 3050S | Leica | ||
| donkey serum | Jackson Immuno Research, Suffolk, GB | 017-000-121 | |
| Dulbecco's Phosphate Buffered Saline | Sigma-Aldrich | D8537 | |
| EDTA | Sigma-Aldrich | E4884 | |
| fetal calf serum | PromoCell, Heidelberg | ||
| Formaldehyde solution (4%) | PanReac AppliChem | A3697 | |
| Gelatine from porcine skin, Type A | Sigma-Aldrich, Steinheim | G2500 | |
| glass coverslips | VWR | 631-0146 | |
| Glucose | Sigma-Aldrich | G7021 | |
| Heidelberger extension tube | IMPROMEDIFORM GmbH | MF 1833 | |
| Heparin-Natrium | Ratiopharm | 5394.02.00 | |
| HEPES | Sigma-Aldrich | H3375 | |
| HistoBond microscope slides | Marienfeld | 0810000 | |
| Hoechst 33342 (1mg/ml) | Sigma Aldrich, Taufkirchen | B2261 | |
| Insulin syringe | Becton Dickinson GmbH | 300334 | |
| Iscove’s ModifiedDulbecco’s Medium (IMDM) | Gibco/Life Technologies, Darmstadt | 21980-032 | |
| KCl | Sigma-Aldrich | P9333 | |
| Laminin | Corning | 354221 | |
| Laser Scanning Mikroskop Eclipse Ti | Nikoninstruments, Düsseldorf | ||
| Lipofectamine RNAiMAX | Invitrogen/Life Technologies, Darmstadt | 13778075 | |
| Mouse IgG Cy5 (donkey) | Jackson ImmunoResearch | 715-175-151 | |
| MGCl | Sigma-Aldrich | M8266 | |
| microcentrifuge tube | Sarstedt | 72690 | |
| Mini shaker | VWR | 12620-940 | |
| mirVana miRNA mimic, hsa-miR199a-3p | Ambion/Thermo Fischer Scientific | 4464066 | |
| Biopsy Mold | Sakura Finetek/ VWR | 4565 | |
| M-slide 8-well ibiTreat | ibidi | 80826 | |
| NaCl | Sigma-Aldrich | S9888 | |
| NaOH | Merck Millipore | 567530 | |
| negative control(scrambled RNA) | Ambion/Thermo Fischer Scientific | AM4611 | |
| Neonatal Heart Dissociation Kit | Miltenyi Biotech, Bergisch Gladbach | 130-098-373 | |
| NIS Elements AR 4.12.01-4.30.02-64bit | Nikoninstruments, Düsseldorf | ||
| Non essential amino acids, NEAA | Gibco/Life Technologies, Darmstad | 11140-035 | |
| Opti-MEM, Reduced Serum Medium | Gibco | 51985-026 | |
| P21-siRNA | Ambion/Thermo Fischer Scientific | 4390771 | |
| P27-siRNA | Ambion/Thermo Fischer Scientific | 4390771 | |
| Penicillin/Streptomycin | Gibco/Life Technologies, Darmstadt | 15140-122 | |
| Phosphate buffered saline (PBS) | Sigma-Aldrich, Steinheim | 14190-094 | |
| Polyvinyl alcohol mounting medium with DABCO®, antifading | Sigma-Aldrich | 10981 | |
| RNase A | Qiagen | 1007885 | |
| RNaseZap | Invitrogen/Life Technologies, Darmstadt | AM9780 | |
| sample containers | Vitlab | 80731 | |
| Serological pipette | Greiner | 607180 | |
| software NIS Elements | Nikon | ||
| Sucrose | Sigma-Aldrich | S0389 | |
| Tissue-Tek O.C.T. Compound | Sakura Finetek/ VWR | 25608-930 | |
| ToPro3 iodide (642/661) | Molecular probes/ThermoFisher Scientific | T3605 | |
| Tris | Sigma-Aldrich | T1503 | |
| Triton X | Fluka | 93418 | |
| Triton X-100 | Fluka | 93418 | |
| Trypsin | Sigma-Aldrich | T1426 | |
| Wheat germ agglutinine (WGA) Fluorescein labeled | Vector Laboratories | VEC-FL-1021-5 | |
| α-actinin antibody | Sigma-Aldrich | A7811 | |
| β-Mercaptoethanol | Sigma-Aldrich, Steinheim | M3148 |
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