Name: transfer of mammary gland-forming ability between mammary basal epithelial cells and mammary luminal cells via extracellular vesicles/exosomes
Uploaded: 2017-06-03T14:00:00
Description: Watch this Scientific Journal Video about Transfer of Mammary Gland-forming Ability Between Mammary Basal Epithelial Cells and Mammary Luminal Cells via Extracellular Vesicles/Exosomes at JoVE.com

This work was supported by grants from the National Health Research Institutes (05A1-CSPP16-014, H.J.L.) and from the Ministry of Science and Technology (MOST 103-2320-B-400-015-MY3, H.J.L).

All research involving animals complied with protocols approved by the Institutional Committee on Animal Care.
1. Extracellular Vesicle/exosome Isolation and Validation
<ol>
	<li>Culture mammary epithelial basal cells, NAMECs4, with fresh, serum-free medium made of 500 mL of MCDB 170, pH 7.4 + 500 mL of DMEM/F12 with sodium bicarbonate (0.2438%); EGF (5 ng/mL); hydrocoritisone (0.5 &#181;g/mL); insulin (5 &#181;g/mL); bovine pituitary extract (BPE; 35 &#181;g/mL); and...

<ol>
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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=PGE2+/EP4+Signaling+Controls+the+Transfer+of+the+Mammary+Stem+Cell+State+by+Lipid+Rafts+in+Extracellular+Vesicles.">PGE2 /EP4 Signaling Controls the Transfer of the Mammary Stem Cell State by Lipid Rafts in Extracellular Vesicles.</a> Stem Cells. , (2016).</li><li>Th&#233;ry, C., Amigorena, S., Raposo, G., Clayton, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+characterization+of+exosomes+from+cell+culture+supernatants+and+biological+fluids.">Isolation and characterization of exosomes from cell culture supernatants and biological fluids.</a> Curr Protoc Cell Biol. , (2006).</li><li>Gy&#246;rgy, B., 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=Membrane+vesicles,+current+state-of-the-art:+emerging+role+of+extracellular+vesicles.">Membrane vesicles, current state-of-the-art: emerging role of extracellular vesicles.</a> Cell Mol Life Sci. 68 (16), 2667-2688 (2011).</li><li>Olver, C., Vidal, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+analysis+of+secreted+exosomes.">Proteomic analysis of secreted exosomes.</a> Subcell Biochem. 43, 99-131 (2007).</li><li>Shackleton, 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=Generation+of+a+functional+mammary+gland+from+a+single+stem+cell.">Generation of a functional mammary gland from a single stem cell.</a> Nature. 439 (7072), 84-88 (2006).</li><li>Prater, M. D., 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=Mammary+stem+cells+have+myoepithelial+cell+properties.">Mammary stem cells have myoepithelial cell properties.</a> Nat Cell Biol. 16 (10), 942-950 (2014).</li><li>Stingl, 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=Purification+and+unique+properties+of+mammary+epithelial+stem+cells.">Purification and unique properties of mammary epithelial stem cells.</a> Nature. 439 (7079), 993-997 (2006).</li><li>Gardiner, C., Ferreira, Y. J., Dragovic, R. A., Redman, C. W., Sargent, I. 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V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+weight+estimation+of+polypeptide+chains+by+electrophoresis+in+SDS-polyacrylamide+gels.">Molecular weight estimation of polypeptide chains by electrophoresis in SDS-polyacrylamide gels.</a> Biochem Biophys Res Commun. 28 (5), 815-820 (1967).</li><li>Riches, A., Campbell, E., Borger, E., Powis, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+exosome+release+from+mammary+epithelial+and+breast+cancer+cells+-+a+new+regulatory+pathway.">Regulation of exosome release from mammary epithelial and breast cancer cells - a new regulatory pathway.</a> Eur J Cancer. 50 (5), 1025-1034 (2014).</li><li>Witwer, K. W., 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=Standardization+of+sample+collection,+isolation+and+analysis+methods+in+extracellular+vesicle+research.">Standardization of sample collection, isolation and analysis methods in extracellular vesicle research.</a> J Extracell Vesicles. 2, (2013).</li><li>van der Vlist, E. J., Nolte-'t Hoen, E. N., Stoorvogel, W., Arkesteijn, G. J., Wauben, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+labeling+of+nano-sized+vesicles+released+by+cells+and+subsequent+quantitative+and+qualitative+analysis+by+high-resolution+flow+cytometry.">Fluorescent labeling of nano-sized vesicles released by cells and subsequent quantitative and qualitative analysis by high-resolution flow cytometry.</a> Nat Protoc. 7 (7), 1311-1326 (2012).</li><li>Kowal, 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=Proteomic+comparison+defines+novel+markers+to+characterize+heterogeneous+populations+of+extracellular+vesicle+subtypes.">Proteomic comparison defines novel markers to characterize heterogeneous populations of extracellular vesicle subtypes.</a> Proc Natl Acad Sci U S A. 113 (8), E968-E977 (2016).</li><li>Li, D., 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=ADVANCED+IMAGING.+Extended-resolution+structured+illumination+imaging+of+endocytic+and+cytoskeletal+dynamics.">ADVANCED IMAGING. Extended-resolution structured illumination imaging of endocytic and cytoskeletal dynamics.</a> Science. 349 (6251), (2015).</li><li>Outzen, H. C., Custer, R. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+human+normal+and+neoplastic+mammary+tissues+in+the+cleared+mammary+fat+pad+of+the+nude+mouse.">Growth of human normal and neoplastic mammary tissues in the cleared mammary fat pad of the nude mouse.</a> J Natl Cancer Inst. 55 (6), 1461-1466 (1975).</li><li>Sheffield, L. G., Welsch, C. 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Exosomes often carry characteristics of the cells that released them, and the amount of released exosomes can be induced by stimuli4. The culture medium of cells can be collected and subjected to differential ultracentrifugation for EV/exosome collection (Figure 1). There is currently no general agreement on an ideal method to isolate EVs/exosomes. The optimal method used here has been determined by the downstream application14. Ultracentrifuga...

Exosomes can mediate cellular communication by transferring membrane and cytosolic proteins, lipids, and RNAs between cells1. Exosome-mediated communication has been demonstrated to be involved in many physiological and pathological processes (i.e., antigen presentation, development of tolerance2, and tumor progression3). Exosomes often have contents similar to those of the source cells releasing them. Thus, the exosomes can carry specific cell properties from the source cells and transfer these properties to the cells ingesting them4.
Exosomes are 50- to 150-nm double-layer membrane vesicles and present specific markers (e.g., CD9, CD81, CD63, HSP70, Alix, and TSG101). Thus, exosomes must be characterized by various methods for different aspects. Transmission electron microscopy can be used to visualize membrane vesicles such as exosomes4,5. Nanoparticle tracking analysis (NTA) and dynamic light scattering analysis (DLS) are used for measuring the size and number of purified exosomes4. The lipid membrane content of exosomes can be verified by density gradient. Exosomal markers, such as CD9, CD81, CD63, HSP70, Alix, and TSG1016,7, can be measured by Western blotting.
Mammary basal cells have the ability to generate mammary glands when implanted into fat pads, while luminal cells cannot8,9,10. Thus, mammary basal cells are also referred to as mammary repopulating units. By using the model of mammary basal and luminal cells, the ability of EVs/exosomes to transfer cell characteristics between different cell populations can be examined. This work demonstrates the method of transferring gland-forming ability from mammary basal epithelial cells to mammary luminal epithelial cells by using EVs/exosomes derived from mammary basal epithelial cells. Luminal mammary epithelial cells acquired basal cell properties following the ingestion of EVs/exosomes secreted from basal cells and can then form mammary glands4.

<table>
	<tbody>
		<tr>
			<td>MCDB 170&#160;</td>
			<td>USBiological</td>
			<td>M2162</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM/F12</td>
			<td>Thermo</td>
			<td>1250062</td>
			<td></td>
		</tr>
		<tr>
			<td>Optima L-100K ultracentrifuge</td>
			<td>Beckman</td>
			<td>393253</td>
			<td></td>
		</tr>
		<tr>
			<td>SW28 Ti Rotor</td>
			<td>Beckman</td>
			<td>342204</td>
			<td></td>
		</tr>
		<tr>
			<td>SW41 Rotor</td>
			<td>Beckman</td>
			<td>331306</td>
			<td></td>
		</tr>
		<tr>
			<td>NANOSIGHT LM10</td>
			<td>Malvern</td>
			<td>NANOSIGHT LM10</td>
			<td>for nanoparticle tracking analysis (NTA)</td>
		</tr>
		<tr>
			<td>Optiprep&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>D1556</td>
			<td>60% (w/v) solution of iodixanol in water (sterile).</td>
		</tr>
		<tr>
			<td>CD81 antibody</td>
			<td>GeneTex</td>
			<td>GTX101766</td>
			<td>1:1000 in 5% w/v nonfat dry milk, 1X TBS, 0.1% Tween 20 at 4&#176;C, overnight&#160;</td>
		</tr>
		<tr>
			<td>CD9 antibody</td>
			<td>GeneTex</td>
			<td>GTX100912</td>
			<td>1:1000 in 5% w/v nonfat dry milk, 1X TBS, 0.1% Tween 20 at 4&#176;C, overnight&#160;</td>
		</tr>
		<tr>
			<td>CD63 antibody</td>
			<td>Abcam</td>
			<td>Ab59479</td>
			<td>1:1000 in 5% w/v nonfat dry milk, 1X TBS, 0.1% Tween 20 at 4&#176;C, overnight&#160;</td>
		</tr>
		<tr>
			<td>TSG101 antibody</td>
			<td>GeneTex</td>
			<td>GTX118736</td>
			<td>1:1000 in 5% w/v nonfat dry milk, 1X TBS, 0.1% Tween 20 at 4&#176;C, overnight&#160;</td>
		</tr>
		<tr>
			<td>GAPDH</td>
			<td>GeneTex</td>
			<td>GTX100118</td>
			<td>1:6000 in 5% w/v nonfat dry milk, 1X TBS, 0.1% Tween 20 at 4&#176;C, overnight&#160;</td>
		</tr>
		<tr>
			<td>CFSE (carboxyfluorescein succinimidyl diacetate ester)</td>
			<td>Thermo</td>
			<td>V12883</td>
			<td></td>
		</tr>
		<tr>
			<td>FACSCalibur</td>
			<td>BD Biosciences</td>
			<td></td>
			<td>fluorescence cell analyzer</td>
		</tr>
		<tr>
			<td>collagenase Type IV&#160;</td>
			<td>Thermo</td>
			<td>17104019</td>
			<td></td>
		</tr>
		<tr>
			<td>trypsin</td>
			<td>Thermo</td>
			<td>27250018</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;ITS</td>
			<td>Sigma-Aldrich</td>
			<td>I3146</td>
			<td>a mixture of recombinant human insulin, human transferrin, and sodium selenite</td>
		</tr>
		<tr>
			<td>accutase</td>
			<td>ebioscience</td>
			<td>00-4555-56</td>
			<td>a natural enzyme mixture with proteolytic and collagenolytic enzyme activity</td>
		</tr>
		<tr>
			<td>dispase&#160;</td>
			<td>STEMCELL</td>
			<td>7913</td>
			<td>5 mg/ml = 5 U/ml</td>
		</tr>
		<tr>
			<td>anti-CD49f antibody</td>
			<td>Biolegend</td>
			<td>313611</td>
			<td>1:50</td>
		</tr>
		<tr>
			<td>anti-EpCAM antibody</td>
			<td>Biolegend</td>
			<td>118213</td>
			<td>1:200</td>
		</tr>
		<tr>
			<td>FACSAria</td>
			<td>BD Biosciences</td>
			<td></td>
			<td>cell sorter</td>
		</tr>
		<tr>
			<td>carmine alum</td>
			<td>Sigma-Aldrich</td>
			<td>C1022</td>
			<td></td>
		</tr>
		<tr>
			<td>human mammary epithelial cells (HMLE cells, NAMECs)</td>
			<td></td>
			<td></td>
			<td>gifts from Dr. Robert Weinberg</td>
		</tr>
		<tr>
			<td>permount</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>SP15-500</td>
			<td></td>
		</tr>
		<tr>
			<td>sodium bicarbonate</td>
			<td>Zymeset&#160;</td>
			<td>BSB101</td>
			<td></td>
		</tr>
		<tr>
			<td>EGF</td>
			<td>Peprotech</td>
			<td>AF-100-015</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrocoritisone</td>
			<td>Sigma-Aldrich</td>
			<td>SI-H0888</td>
			<td></td>
		</tr>
		<tr>
			<td>Insulin&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>SI-I9278</td>
			<td></td>
		</tr>
		<tr>
			<td>BPE (bovine pituitary extract)</td>
			<td>Hammod Cell Tech&#160;</td>
			<td>1078-NZ</td>
			<td></td>
		</tr>
		<tr>
			<td>GW627368X&#160;</td>
			<td>Cayman</td>
			<td>10009162</td>
			<td></td>
		</tr>
		<tr>
			<td>15-cm culture dish</td>
			<td>Falcon&#160;</td>
			<td>353025</td>
			<td></td>
		</tr>
		<tr>
			<td>table-top centrifuge</td>
			<td>Eppendrof&#160;</td>
			<td>Centrifuge 3415R</td>
			<td></td>
		</tr>
		<tr>
			<td>ultracentrifuge tube</td>
			<td>Beckman</td>
			<td>344058</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS (Phosphate-buffered saline)&#160;</td>
			<td>Corning</td>
			<td>46-013-CM</td>
			<td></td>
		</tr>
		<tr>
			<td>BCA Protein Assay</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>23228</td>
			<td></td>
		</tr>
		<tr>
			<td>Transmission Electron Microscopy</td>
			<td>Hitachi</td>
			<td>HT7700</td>
			<td></td>
		</tr>
		<tr>
			<td>gelatin&#160;</td>
			<td>STEMCELL</td>
			<td>7903</td>
			<td></td>
		</tr>
		<tr>
			<td>10-cm culture dish</td>
			<td>Falcon&#160;</td>
			<td>353003</td>
			<td></td>
		</tr>
		<tr>
			<td>6-well culture dish</td>
			<td>Corning</td>
			<td>3516</td>
			<td></td>
		</tr>
		<tr>
			<td>female C57BL/6 mice</td>
			<td>NLAC (National Laboratory Animal Center</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>FBS (Fetal Bovine Serum)</td>
			<td>BioWest&#160;</td>
			<td>S01520</td>
			<td></td>
		</tr>
		<tr>
			<td>gentamycin</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>15710072</td>
			<td></td>
		</tr>
		<tr>
			<td>Pen/Strep</td>
			<td>Corning</td>
			<td>30-002-Cl</td>
			<td></td>
		</tr>
		<tr>
			<td>DNase I</td>
			<td>5PRIMER</td>
			<td>2500120</td>
			<td></td>
		</tr>
		<tr>
			<td>isofluorane&#160;</td>
			<td>Halocarbon</td>
			<td>NPC12164-002-25</td>
			<td></td>
		</tr>
		<tr>
			<td>formaldehyde</td>
			<td>MACRON</td>
			<td>H121-08</td>
			<td></td>
		</tr>
		<tr>
			<td>EtOH (Ethanol)</td>
			<td>J.T. Baker</td>
			<td>800605</td>
			<td></td>
		</tr>
		<tr>
			<td>glacial acetic acid</td>
			<td>Panreac</td>
			<td>131008.1611</td>
			<td></td>
		</tr>
		<tr>
			<td>aluminum potassium sulfate</td>
			<td>Sigma-Aldrich</td>
			<td>12625</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylene&#160;</td>
			<td>Leica</td>
			<td>3803665</td>
			<td></td>
		</tr>
		<tr>
			<td>0.22 &#956;m membranes</td>
			<td>Merck Millipore</td>
			<td>Millex-GP</td>
			<td></td>
		</tr>
		<tr>
			<td>AUTOCLIP Wound Clips, 9 mm</td>
			<td>BD Biosciences</td>
			<td>427631</td>
			<td></td>
		</tr>
		<tr>
			<td>AUTOCLIP Wound Clip Applier</td>
			<td>BD Biosciences</td>
			<td>427630</td>
			<td></td>
		</tr>
		<tr>
			<td>CellMask&#8482; Deep Red</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>C10046</td>
			<td>plasma membrane stain</td>
		</tr>
	</tbody>
</table>

transfer of mammary gland-forming ability between mammary basal epithelial cells and mammary luminal cells via extracellular vesicles/exosomes

Cells can communicate via exosomes, ~100-nm extracellular vesicles (EVs) that contain proteins, lipids, and nucleic acids. Non-adherent/mesenchymal mammary epithelial cell (NAMEC)-derived extracellular vesicles can be isolated from NAMEC medium via differential ultracentrifugation. Based on their density, EVs can be purified via ultracentrifugation at 110,000 x g. The EV preparation from ultracentrifugation can be further separated using a continuous density gradient to prevent contamination with soluble proteins. The purified EVs can then be further evaluated using nanoparticle-tracking analysis, which measures the size and number of vesicles in the preparation. The extracellular vesicles with a size ranging from 50 to 150 nm are exosomes. The NAMEC-derived EVs/exosomes can be ingested by mammary epithelial cells, which can be measured by flow cytometry and confocal microscopy. Some mammary stem cell properties (e.g., mammary gland-forming ability) can be transferred from the stem-like NAMECs to mammary epithelial cells via the NAMEC-derived EVs/exosomes. Isolated primary EpCAMhi/CD49flo luminal mammary epithelial cells cannot form mammary glands after being transplanted into mouse fat pads, while EpCAMlo/CD49fhi basal mammary epithelial cells form mammary glands after transplantation. Uptake of NAMEC-derived EVs/exosomes by EpCAMhi/CD49flo luminal mammary epithelial cells allows them to generate mammary glands after being transplanted into fat pads. The EVs/exosomes derived from stem-like mammary epithelial cells transfer mammary gland-forming ability to EpCAMhi/CD49flo luminal mammary epithelial cells.

Since it has been shown that blocking PGE2/EP4 signaling triggers EV/exosome release from mammary basal-like stem cells4, this work presents a method of isolating the induced EVs/exosomes from mammary epithelial basal cell (NAMEC) culture. Since NAMECs are cultured in serum-free medium, there are no pre-existing EVs/exosomes derived from serum13. For cells cultured in serum-containing medium, pre-existing exosomes in th...

Watch this Scientific Journal Video about Transfer of Mammary Gland-forming Ability Between Mammary Basal Epithelial Cells and Mammary Luminal Cells via Extracellular Vesicles/Exosomes at JoVE.com

Transfer of Mammary Gland-forming Ability Between Mammary Basal Epithelial Cells and Mammary Luminal Cells via Extracellular Vesicles/Exosomes

This protocol describes methods for purifying, quantitating, and characterizing extracellular vesicles (EVs)/exosomes from non-adherent/mesenchymal mammary epithelial cells and for using them to transfer mammary gland-forming ability to luminal mammary epithelial cells. EVs/exosomes derived from stem-like mammary epithelial cells can transfer this cell property to cells that ingest the EVs/exosomes.

Cells can communicate via exosomes, ~100-nm extracellular vesicles (EVs) that contain proteins, lipids, and nucleic acids. Non-adherent/mesenchymal ...

The overall goals of this procedure are to isolate stem ness transferring extra cellular vesicles and exosomes from stem cells. And to assess the stem ness transferring ability of these nano-particles. The meso can answer key questions in the stem cell field about weather stem cell derive in trans cell or vesicle.Or exosome can transfer stem cell property to non stem cell. The main advantage of this technique is that the induced stem cell derive in trans cell vesicle. And the exosome can be used to directly reprogramming non stem cell into stem cell.Demonstrating the procedure will be postal researcher LeMonsier, with surgical assistant, Pei-Ling, Wen-Tin, and Shih-Yin, all from my laboratory. Begin by seeding one point two times ten to the sixth non-adherent/mesenchymal mammary epithelial cells, or NAMECs in 12 milliliters of medium per 15 centimeter dish for a four day culture in a cell culture incubator. On day four, harvest the culture medium for table top centrufigation.Then transfer the supernatent into a conical tube for a second table top centrifugation. Next, transfer the supernatent into a new ultra-centrifuge and perform ultracentrifugation for 30 minutes. At the end of the spin, transfer the supernatent into a new ultra-centrifuge tube and ultra-centrifuge the supernatent again.Remove the supernatent and re-suspend the extra-cellular vesicle exosome palate in PBS for a third ultracentrifugation. Then, re-suspend the palate in fresh PBS and ultra-centrifuge the cell particles one final time. Remove the supernatent and re-suspend the extra cellular vesicle exosome palate in 100 microliters of PBS.Then, measure the protein concentration of the extra cellular vesicle suspension by bicinchoninic acid assay. The concentration should be approximately 20 to 40 micrograms per 100 microliters. To measure the concentration and the size of the extra cellular vesicles and exosomes, dilute the cell particles to two micrograms of protein per 100 milliliters of PBS.And analyze the particles by nanoparticle tracking analysis. To purify the exosomes by density gradient, after the third ultracentrifugation, resuspend the palate in two milliliters of 40 percent iodixanol in PBS. And overlay the cell suspension with sequential two milliliter volumes of 30 percent, 20 percent, 10 percent and five percent iodixanol.Separate the cell fraction by density gradient ultracentrifugation using a pipette to harvest each of the ten gradient layers at the end of the centrifugation. Then, analyze the presence of exosome markers in each fraction by SDS page and western blot according to standard protocols. Using antibodies against the appropriate exosome markers of interest.To treat mammary epithelial cells with the extra cellular vesicles and exosomes first, seed two times tent to the fifth flow sorted epcam hi-CD 49F low luminal mammary epithelial cells per plate onto gelatine coated six well plates. Then, treat each cellular culture with two micrograms per milliliter of the NAMEC derived extra cellular vesicles and exsomes. Replacing the cultured medium with fresh extra cellular vesicles and exosomes every two days for ten days.At the end of the treatment period, place a three week old female anesthetized 57 BL6 mouse in the supine position, and remove the fur on the mid-abdomen. Disinfect the surgery site with three alternating cycles of 70 percent alcohol and povodone iodine. And make a one point five centimeter vertical incision through the skin, along the ventral thorassic inguinal region.Alternately expose the right and left fourth mammary fat pads. Locate the lymph node in each fat pad and remove the whole gland perancama below the lymph node. Next, use a natural enzyme with prodialitic and cologenalitic activity to detach the extra cellular vesical and exsome treated luminal mammary epithelial cells.Neutralizing the enzyme activity, with five percent FBS in PBS after ten minutes. Collect the cells by centrifugation and discard the supernatent. After counting, dilute the cells to one times ten to the second to one times ten to the fourth cells per 15 microliters of PBS concentration.And use a 100 liter microliter glass syringe equipped with a 27 gauge needle to inject 15 microliters of the mammary epithelial cell suspension into each fat pad. Then, close the skin with wound clips. Eight weeks after the injection, make a vertical incision through the skin from the thorassic region to the ingrinal region and expose both the right and left fourth mammary fat pads.Remove the fourth mammary glans and spread the fat pads onto individual glass microscope slides. Then, transfer the slides to a chemical hood, and fix the pads with collies fixatives overnight at room temperature. The next morning, wash the samples in 250 milliliters of 70 percent ethanol for 15 minutes.Followed by 250 milliliters of distilled water for five minutes. After the distilled water wash, stain the fat pads with carmine alum overnight at room temperature. Followed by dehydration in ascending 15 minute ethanol incubations.After the last dehydration, transfer the samples into zylene in a chemical hood until the fat pads become transparent. Then, mount the slides with mounting medium, and use a digital slide scanner to image the fat pads at 2, 400 dots per inch. The size of the isolated vesicles and the ultracentrifuge palate are typically approximately 100 nanometers, as measured by nano particle tracking analysis.Further, transmission electron microscopy analysis of ultracentrifuge fractions of NAMEC conditioned medium reveals the presences of abundant membrane vesicles. After density gradient separation as just demonstrated, exosome markers can be detected in the 20 percent iodixonal fraction. Flow side emetric analysis of human luminal mammary epithelial cells traded with CFSE labeled namic derived, extra cellular vesicles and exsomes reveals a ten fold higher CFSE signal in the exosome treated cultures.Indicating the specific uptake of CFSE labeled extra cellular vesicles and exosomes, by the mammary epithelial cells. Further, while the negative control, PBS treated mammary epithelial cells do not exhibit a CFSE singnal, evidence of namic derived extra cellular vesical and exosome uptake by the exosome treated cells can also be observed by confocal microscopy. Notably, the fat pads of mice injected with flow sorted epCAMhi/CD49Flo luminal mammary epithelial cells treated with NAMEC derived extra cellular vesicles and exosomes for ten days acquired the ability to form mammary glands.After it's development, this tech paved the way for our researcher in the field of stem cell biology. To explore in the usage of the stem cell derived trans cell and vesicle and exosome in regeneration medicine and direct cell reprogramming.

transfer-mammary-gland-forming-ability-between-mammary-basal

Research

JoVE Journal

Developmental Biology

Cultivate Primary Nasal Epithelial Cells from Children and Reprogram into Induced Pluripotent Stem Cells

Nasal epithelial cells (NECs) are the part of the airways that respond to air pollutants and are the first cells infected with respiratory viruses. They are also involved in many airway diseases through their innate immune response and interaction with immune and airway stromal cells. NECs are of particular interest for studies in children due to their accessibility during clinical visits. Human induced pluripotent stem cells (iPSCs) have been generated from multiple cell types and are a powerful tool for modeling human development and disease, as well as for their potential applications in regenerative medicine. This is the first protocol to lay out methods for successful generation of iPSCs from NECs derived from pediatric participants for research purposes. It describes how to obtain nasal epithelial cells from children, how to generate primary NEC cultures from these samples, and how to reprogram primary NECs into well-characterized iPSCs. Nasal mucosa samples are useful in epidemiological studies related to the effects of air pollution in children, and provide an important tool for studying airway disease. Primary nasal cells and iPSCs derived from them can be a tool for providing unlimited material for patient-specific research in diverse areas of airway epithelial biology, including asthma and COPD research.

This publication demonstrates methods for successful sampling and culture of nasal epithelial mucosa from children, and reprogramming these cells to induced Pluripotent Stem Cells (iPSCs).

Nasal epithelial cells (NECs) are the part of the airways that respond to air pollutants and are the first cells infected with respiratory viruses. They ...

Induction of Mesenchymal-Epithelial Transitions in Sarcoma Cells

Phenotypic plasticity refers to a phenomenon in which cells transiently gain traits of another lineage. During carcinoma progression, phenotypic plasticity drives invasion, dissemination and metastasis. Indeed, while most of the studies of phenotypic plasticity have been in the context of epithelial-derived carcinomas, it turns out sarcomas, which are mesenchymal in origin, also exhibit phenotypic plasticity, with a subset of sarcomas undergoing a phenomenon that resembles a mesenchymal-epithelial transition (MET). Here, we developed a method comprising the miR-200 family and grainyhead-like 2 (GRHL2) to mimic this MET-like phenomenon observed in sarcoma patient samples.We sequentially express GRHL2 and the miR-200 family using cell transduction and transfection, respectively, to better understand the molecular underpinnings of these phenotypic transitions in sarcoma cells. Sarcoma cells expressing miR-200s and GRHL2 demonstrated enhanced epithelial characteristics in cell morphology and alteration of epithelial and mesenchymal biomarkers. Future studies using these methods can be used to better understand the phenotypic consequences of MET-like processes on sarcoma cells, such as migration, invasion, metastatic propensity, and therapy resistance.

We present here a cell culture method for inducing mesenchymal-epithelial transitions (MET) in sarcoma cells based on combined ectopic expression of microRNA-200 family members and grainyhead-like 2 (GRHL2). This method is suitable for better understanding the biological impact of phenotypic plasticity on cancer aggressiveness and treatments.

Phenotypic plasticity refers to a phenomenon in which cells transiently gain traits of another lineage. During carcinoma progression, phenotypic ...

Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands

Cell-cell interactions play a pivotal role in preserving tissue integrity and the barrier between the different compartments of the mammary gland. These interactions are provided by junctional proteins that form nexuses between adjacent cells. Junctional protein mislocalization and reduced physical associations with their binding partners can result in the loss of function and, consequently, to organ dysfunction. Thus, identifying protein localization and protein-protein interactions (PPIs) in normal and disease-related tissues is essential to finding new evidences and mechanisms leading to the progression of diseases or alterations in developmental status. This manuscript presents a two-step method to evaluate PPIs in murine mammary glands. In protocol section 1, a method to perform co-immunofluorescence (co-IF) using antibodies raised against the proteins of interest, followed by secondary antibodies labeled with fluorochromes, is described. Although co-IF allows for the demonstration of the proximity of the proteins, it does make it possible to study their physical interactions. Therefore, a detailed protocol for co-immunoprecipitation (co-IP) is provided in protocol section 2. This method is used to determine the physical interactions between proteins, without confirming whether these interactions are direct or indirect. In the last few years, co-IF and co-IP techniques have demonstrated that certain components of intercellular junctions co-localize and interact together, creating stage-dependent junctional nexuses that vary during mammary gland development.

Intercellular junctions are requisites for mammary gland stage-specific functions and development. This manuscript provides a detailed protocol for the study of protein-protein interactions (PPIs) and co-localization using murine mammary glands. These techniques allow for the investigation of the dynamics of the physical association between intercellular junctions at different developmental stages.

Cell-cell interactions play a pivotal role in preserving tissue integrity and the barrier between the different compartments of the mammary gland. These ...

Quantifying Branching Density in Rat Mammary Gland Whole-mounts Using the Sholl Analysis Method

An increasing number of studies are utilizing the rodent mammary gland as an endpoint for assessing the developmental toxicity of a chemical exposure. The effects these exposures have on mammary gland development are typically evaluated using either basic dimensional measurements or by scoring morphological characteristics. However, the broad range of methods for interpreting developmental changes could lead to inconsistent translations across laboratories. A common method of assessment is needed so that proper interpretations can be formed from data being compared across studies. The present study describes the application of the Sholl analysis method to quantify mammary gland branching characteristics. The Sholl method was originally developed for use in quantifying neuronal dendritic patterns. By using ImageJ, an open-source image analysis software package, and a plugin developed for this analysis, the mammary gland branching density and the complexity of a mammary gland from a peripubertal female rat were determined. The methods described here will enable the use of the Sholl analysis as an effective tool for quantifying an important characteristic of mammary gland development.

Mammary gland development in the rodent has typically been evaluated using descriptive assessments or by measuring basic physical attributes. Branching density is an indicator of mammary development that is difficult to quantify objectively. This protocol describes a reliable method for the quantitative assessment of mammary gland branching characteristics.

An increasing number of studies are utilizing the rodent mammary gland as an endpoint for assessing the developmental toxicity of a chemical exposure. The ...

A Novel Mammary Fat Pad Transplantation Technique to Visualize the Vessel Generation of Vascular Endothelial Stem Cells

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper vessel development and homeostasis. However, studies on endothelial lineage hierarchy remain elusive due to the lack of tools to gain access as well as to directly evaluate their behavior in vivo. To address this shortcoming, a new tissue model to study angiogenesis using the mammary fat pad has been developed. The mammary gland develops mostly in the postnatal stages, including puberty and pregnancy, during which robust epithelium proliferation is accompanied by extensive vascular remodeling. Mammary fat pads provide space, matrix, and rich angiogenic stimuli from the growing mammary epithelium. Furthermore, mammary fat pads are located outside the peritoneal cavity, making them an easily accessible grafting site for assessing the angiogenic potential of exogenous cells. This work also describes an efficient tracing approach using fluorescent reporter mice to specifically label the targeted population of vascular endothelial stem cells (VESCs) in vivo. This lineage tracing method, coupled with subsequent tissue whole-mount microscopy, enable the direct visualization of targeted cells and their descendants, through which the proliferation capability can be quantified and the differentiation commitment can be fate-mapped. Using these methods, a population of bipotent protein C receptor (Procr) expressing VESCs has recently been identified in multiple vascular systems. Procr+ VESCs, giving rise to both new ECs and pericytes, actively contribute to angiogenesis during development, homeostasis, and injury repair. Overall, this manuscript describes a new mammary fat pad transplantation and in vivo lineage tracing techniques that can be used to evaluate the stem cell properties of VESCs.

This work demonstrates a novel approach to assess the proliferation, differentiation, and vessel-forming potential of vascular endothelial stem cells (VESCs) through mammary fat pad transplantation followed by whole-mount tissue preparation for microscopic observation. A lineage tracing strategy to investigate the behavior of VESCs in vivo is also presented.

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper ...

Horizontal Whole Mount: A Novel Processing and Imaging Protocol for Thick, Three-dimensional Tissue Cross-sections of Skin

Processing a tissue of interest to generate a microscopic image that supports a scientific argument can be challenging. The acquisition of high-quality microscopic images is not entirely dependent upon the quality of the microscope, but also upon the methods of tissue processing, which often involve multiple critical actions or steps. Furthermore, mesenchymal cell types in the skin and other tissues represent a new challenge for tissue preparation and imaging. Here, we present a complete process, from tissue harvest to microscopy. Our technique, called &#34;horizontal whole mount,&#34; is one that novices can quickly become proficient in and that allows for antigen preservation and detection in 60-300 &#181;m-thick sections cut with a cryostat. Sections of this thickness provide enhanced visualization of tissue microarchitecture in a three-dimensional environment. In addition, the protocol preserves mesenchymal cells in a manner that enhances image quality when compared to standard cryostat or paraffin sections, thereby increasing the efficacy and reliability of immunostaining. We believe that this protocol will benefit all laboratories that visualize skin, and possibly other tissues and organs.

This work presents a novel processing and imaging protocol for thick, three-dimensional tissue cross-section analysis that enables the full exploitation of confocal imaging modalities. This protocol preserves antigenicity and represents a robust system to analyze skin histology and potentially other tissue types.

Processing a tissue of interest to generate a microscopic image that supports a scientific argument can be challenging. The acquisition of high-quality ...

Single-cell Photoconversion in Living Intact Zebrafish

Animal and plant tissue is composed of distinct populations of cells. These cells interact over time to build and maintain the tissue and can cause disease when disrupted. Scientists have developed clever techniques to investigate characteristics and natural dynamics of these cells within intact tissue by expressing fluorescent proteins in subsets of cells. However, at times, experiments require more selected visualization of cells within the tissue, sometimes at the single-cell or population-of-cells manner. To achieve this and visualize single cells within a population of cells, scientists have utilized single-cell photoconversion of fluorescent proteins. To demonstrate this technique, we show here how to direct UV light to an Eos-expressing cell of interest in an intact, living zebrafish. We then image those photoconverted Eos+ cells 24 h later to determine how they changed in the tissue. We describe two techniques: single cell photoconversion and photoconversions of populations of cell. These techniques can be used to visualize cell-cell interactions, cell-fate and differentiation, and cell migrations, making it a technique that is applicable in numerous biological questions.

Here, we present a protocol to show how cell photoconversion is achieved through UV exposure to specific areas expressing the fluorescent protein, Eos, in living animals.

Animal and plant tissue is composed of distinct populations of cells. These cells interact over time to build and maintain the tissue and can cause ...

Identification of Skeletal Muscle Satellite Cells by Immunofluorescence with Pax7 and Laminin Antibodies

Immunofluorescence is an effective method that helps to identify different cell types on tissue sections. In order to study the desired cell population, antibodies for specific cell markers are applied on tissue sections. In adult skeletal muscle, satellite cells (SCs) are stem cells that contribute to muscle repair and regeneration. Therefore, it is important to visualize and trace the satellite cell population under different physiological conditions. In resting skeletal muscle, SCs reside between the basal lamina and myofiber plasma membrane. A commonly used marker for identifying SCs on the myofibers or in cell culture is the paired box protein Pax7. In this article, an optimized Pax7 immunofluorescence protocol on skeletal muscle sections is presented that minimizes non-specific staining and background. Another antibody that recognizes a protein (laminin) of the basal lamina was also added to help identify SCs. Similar protocols can also be used to perform double or triple labeling with Pax7 and antibodies for additional proteins of interest.

The precise identification of satellite cells is essential for studying their functions under various physiological and pathological conditions. This article presents a protocol to identify satellite cells on adult skeletal muscle sections by immunofluorescence-based staining.

Immunofluorescence is an effective method that helps to identify different cell types on tissue sections. In order to study the desired cell population, ...

Computational Analysis of the Caenorhabditis elegans Germline to Study the Distribution of Nuclei, Proteins, and the Cytoskeleton

The Caenorhabditis elegans (C. elegans) germline is used to study several biologically important processes including stem cell development, apoptosis, and chromosome dynamics. While the germline is an excellent model, the analysis is often two dimensional due to the time and labor required for three-dimensional analysis. Major readouts in such studies are the number/position of nuclei and protein distribution within the germline. Here, we present a method to perform automated analysis of the germline using confocal microscopy and computational approaches to determine the number and position of nuclei in each region of the germline. Our method also analyzes germline protein distribution that enables the three-dimensional examination of protein expression in different genetic backgrounds. Further, our study shows variations in cytoskeletal architecture in distinct regions of the germline that may accommodate specific spatial developmental requirements. Finally, our method enables automated counting of the sperm in the spermatheca of each germline. Taken together, our method enables rapid and reproducible phenotypic analysis of the C. elegans germline.

Computational Analysis of the Caenorhabditis elegans Germline to Study the Distribution of Nuclei, Proteins, and the Cytoskeleton

We present an automated method for three-dimensional reconstruction of the Caenorhabditis elegans germline. Our method determines the number and position of each nucleus within the germline and analyses germline protein distribution and cytoskeletal structure.

The Caenorhabditis elegans (C. elegans) germline is used to study several biologically important processes including stem cell development, apoptosis, and ...

In Vitro Generation of Somite Derivatives from Human Induced Pluripotent Stem Cells

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give rise to multiple cell types, including the myotome (MYO), sclerotome (SCL), dermatome (D), and syndetome (SYN), which in turn develop into skeletal muscle, axial skeleton, dorsal dermis, and axial tendon/ligament, respectively. Therefore, the generation of SMs and their derivatives from human induced pluripotent stem cells (iPSCs) is critical to obtain pluripotent stem cells (PSCs) for application in regenerative medicine and for disease research in the field of orthopedic surgery. Although the induction protocols for MYO and SCL from PSCs have been previously reported by several researchers, no study has yet demonstrated the induction of SYN and D from iPSCs. Therefore, efficient induction of fully competent SMs remains a major challenge. Here, we recapitulate human SM patterning with human iPSCs in vitro by mimicking the signaling environment during chick/mouse SM development, and report on methods of systematic induction of SM derivatives (MYO, SCL, D, and SYN) from human iPSCs under chemically defined conditions through the presomitic mesoderm (PSM) and SM states. Knowledge regarding chick/mouse&#160;SM development was successfully applied to the induction of SMs with human iPSCs. This method could be a novel tool for studying human somitogenesis and patterning without the use of embryos and for cell-based therapy and disease modeling.

We present here a protocol for the differentiation of human induced pluripotent stem cells into each somite derivative (myotome, sclerotome, dermatome, and syndetome) in chemically defined conditions, which has applications in future disease modeling and cell-based therapies in orthopedic surgery.

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give ...