Name: nanopodia - thin, fragile membrane projections with roles in cell movement and intercellular interactions
Uploaded: 2014-04-03T15:45:00
Description: Watch this Scientific Journal Video about Nanopodia - Thin, Fragile Membrane Projections with Roles in Cell Movement and Intercellular Interactions at JoVE.com

We acknowledge Dr. Harold Dvorak for helpful discussions including the suggestion to try fixation in 37&#160;&#176;C PFA. This work was supported by NIH grant P01 CA92644 and by a contract from the National Foundation for Cancer Research.

1. Cell Culture on Collagen Coated Glass Disk
<ol>
	<li>Place glass disks (12 mm in diameter) in a glass jar (4 oz) and autoclave to sterilize the discs.</li>
	<li>Put 25 ml 70% ethanol in a 50&#160;ml Falcon tube and place it in a cell culture hood. This solution can be reused multiple times until the level of the solution drops to 20 ml.</li>
	<li>Place a sharp forceps with an extra fine point in the 70% ethanol for 5 min before using it to handle the glass disk.</li>
	<li>Carefully remove the forceps out of the tube...

<ol>
	<li>Chhabra, E. S., Higgs, H. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+many+faces+of+actin:+matching+assembly+factors+with+cellular+structures.">The many faces of actin: matching assembly factors with cellular structures.</a> Nat. Cell Biol. 9, 1110-1121 (2007).</li><li>Shih, S. 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=The+L6+protein+TM4SF1+is+critical+for+endothelial+cell+function+and+tumor+angiogenesis.">The L6 protein TM4SF1 is critical for endothelial cell function and tumor angiogenesis.</a> Cancer Res. 69, 3272-3277 (2009).</li><li>Zukauskas, A., 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=TM4SF1:+a+tetraspanin-like+protein+necessary+for+nanopodia+formation+and+endothelial+cell+migration.">TM4SF1: a tetraspanin-like protein necessary for nanopodia formation and endothelial cell migration.</a> Angiogenesis. 14, 345-354 (2011).</li><li>Hellstrom, I., Beaumier, P. L., Hellstrom, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antitumor+effects+of+L6,+an+IgG2a+antibody+that+reacts+with+most+human+carcinomas.">Antitumor effects of L6, an IgG2a antibody that reacts with most human carcinomas.</a> Proc. Natl. Acad. Sci. U.S.A. 83, 7059-7063 (1986).</li><li>Jang, Y. Y., Ye, Z., Cheng, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+imaging+and+stem+cell+research.">Molecular imaging and stem cell research.</a> Mol. Imag. 10, 111-122 (2011).</li><li>Hemler, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetraspanin+functions+and+associated+microdomains.">Tetraspanin functions and associated microdomains.</a> Nat. Rev. Mol. Cell Biol. 6, 801-811 (2005).</li><li>Vasile, E., Tomita, Y., Brown, L. F., Kocher, O., Dvorak, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+expression+of+thymosin+beta-10+by+early+passage+and+senescent+vascular+endothelium+is+modulated+by+VPF/VEGF:+evidence+for+senescent+endothelial+cells+in+vivo+at+sites+of+atherosclerosis.">Differential expression of thymosin beta-10 by early passage and senescent vascular endothelium is modulated by VPF/VEGF: evidence for senescent endothelial cells in vivo at sites of atherosclerosis.</a> FASEB. 15, 458-466 (2001).</li><li>Itoh, T. J., Hotani, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microtubule+dynamics+and+the+regulation+by+microtubule-associated+proteins+(MAPs).">Microtubule dynamics and the regulation by microtubule-associated proteins (MAPs).</a> Uchu Seibutsu Kagaku. 18, 116-117 (2004).</li><li>Caplow, M., Shanks, J., Ruhlen, 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=Temperature-jump+studies+of+microtubule+dynamic+instability.">Temperature-jump studies of microtubule dynamic instability.</a> J. Biol. Chem. 263, 10344-10352 (1988).</li><li>Pollice, A. A., 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=Sequential+paraformaldehyde+and+methanol+fixation+for+simultaneous+flow+cytometric+analysis+of+DNA,+cell+surface+proteins,+and+intracellular+proteins.">Sequential paraformaldehyde and methanol fixation for simultaneous flow cytometric analysis of DNA, cell surface proteins, and intracellular proteins.</a> Cytometry. 13, 432-444 (1992).</li><li>Macarulla, J. 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=Membrane+solubilization+by+the+non-ionic+detergent+triton+X-100.+A+comparative+study+including+model+and+cell+membranes.">Membrane solubilization by the non-ionic detergent triton X-100. A comparative study including model and cell membranes.</a> Revista Espanola de Fisiologia. 45 Suppl, 1-8 (1989).</li><li>Koley, D., Bard, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Triton+X-100+concentration+effects+on+membrane+permeability+of+a+single+HeLa+cell+by+scanning+electrochemical+microscopy+(SECM).">Triton X-100 concentration effects on membrane permeability of a single HeLa cell by scanning electrochemical microscopy (SECM).</a> Proc. Natl. Acad. Sci. U.S.A. 107, 16783-16787 (2010).</li><li>Chang, Y. 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=CD13+(aminopeptidase+N)+can+associate+with+tumor-associated+antigen+L6+and+enhance+the+motility+of+human+lung+cancer+cells.">CD13 (aminopeptidase N) can associate with tumor-associated antigen L6 and enhance the motility of human lung cancer cells.</a> Int. J. Cancer. 116, 243-252 (2005).</li></ol>

Nanopodia are thin cellular membrane channels that firmly attach to matrix through TMED and can extend more than 100 &#956;m from a polarized mobile cell to sense the environment and mediate intercellular interactions2,3. Nanopodia adhere to matrix so firmly that residues are left behind as the cell moves away (Figures 1 and 2). Nanopodia thus allow us to study how cells sense their environment and determine the path of cell movement, and how gene expression or drug treatment ...

During polarization for movement, animal cells extend a variety of dynamic, membrane protrusions from their surfaces, including filopodia, lamellipodia, retraction fibers, and ruffles1. Recently added to this list were nanopodia, a newly recognized type of thin (100-300 &#956;m in diameter), elongated (up to 50-100 &#956;m long) membrane projection that provide membrane channels for the extension of F-actin structures such as filopodia and retraction fiber, and that stain positively with TM4SF1 (Transmembrane-4-L-six-family-1) in cultured endothelial and tumor cells2,3.
TM4SF1 is a protein with tetraspanin-like topology that was originally known as a tumor cell antigen4 before the discovery that the molecule is an endothelial cell biomarker that plays an essential role in endothelial cell proliferation and migration2,3. Immunofluorescence staining revealed that TM4SF1 is localized to perinuclear vesicles and to the plasma membrane, and is enriched in TM4SF1 enriched microdomains (TMED). TMED anchor nanopodia to matrix and present in a regularly spaced banded pattern of 1-3 TMED/&#181;m length of nanopodia. Nanopodia typically extend from a cell's leading front and trailing rear during cell polarization for movement. Due to the firm adherent nature of TMED, nanopodia are unable to retract back into the cell as it moves away; abandoned nanopodia residues thus trace out the path of cellular movement. Nanopodia provide membrane channels for F-actin extension and retraction, and are sites of intercellular interactions and communications2,3. These characteristics mean that nanopodia provide a unique opportunity to study the mechanisms underlying F-actin assembly during cellular polarization, cellular sensing of the environment, determination of the path and direction of cell movement, and intercellular interactions and communications.
Due to the highly hydrophobic nature of TMED and the thin and fragile membranous nature of nanopodia, special care needs to be taken in order to preserve TMED and nanopodia. The destruction of nanopodia and removal of TMED by common laboratory methods is a possible reason why only sixty-three publications have appeared on TM4SF1 since its first discovery in 19861&#160;and for the complete lack of knowledge of TM4SF1 enrichment in 100-300 &#956;m microdomains on the cell surface until the report of TM4SF1 in endothelial cells in 20092.
Conventional immunostaining methods commonly use organic solvents like ethanol, methanol, or acetone to fix cells and use 0.1% or higher Triton X-100 concentration to permeabilize cells5. Studies described here implemented three major changes to the conventional method to reveal TMED and nanopodia: (i) use 37 &#176;C 4% PFA and fix cells in a 37 &#176;C incubator, (ii) apply gentle room temperature PBS washing, and (iii) use less than 0.03% Triton X-100 only briefly to permeabilize cells before addition of primary antibody, as Triton X-100 higher than 0.03% will extract TM4SF1.
All tetraspanins form microdomains on the cell membrane6 and some colocalize with TMED in endothelial and tumor cells2,3. As tetraspanins like CD9, CD81, and CD151 are ubiquitously expressed, the staining protocol described here can be extended to many different cell types that lack TM4SF1 for the studies of nanopodia function.

<table border="0" cellpadding="0" cellspacing="0" width="1597">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">glass discs&#160;</td>
			<td style="width:160px;">Fisher Scientific</td>
			<td style="width:133px;">12-545-82&#160;</td>
			<td style="width:983px;">12-mm diameter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">glass jar</td>
			<td>Fisher Scientific</td>
			<td>02-912-310</td>
			<td>Certified Clean Clear Glass Straight-Sided Jars, 4 oz.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">glass slide</td>
			<td>Fisher Scientific</td>
			<td style="width:133px;">12-544-1</td>
			<td>Fisherfinest Premium Plain Glass Microscope Slides</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">50-ml falcon tube&#160;</td>
			<td style="width:160px;">BD Falcon</td>
			<td style="width:133px;">352070</td>
			<td>50-ml high-clarity polypropylene conical centrifuge tube, 16,000 rcf rating. Sterile.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">15-ml falcon tube with Styrofoam rack</td>
			<td style="width:160px;">Corning</td>
			<td style="width:133px;">430790</td>
			<td>Corning 15-ml PP Centrifuge Tubes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Sharp forceps&#160;</td>
			<td>Fisher Scientific</td>
			<td style="width:133px;">13-812-42</td>
			<td>Dissecting Extra-Fine-Pointed Splinter Forceps</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">24-well cell culture plate</td>
			<td style="width:160px;">BD Bioscience</td>
			<td style="width:133px;">353047</td>
			<td>24-well Cell Culture Plate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">150-mm cell culture plate&#160;</td>
			<td style="width:160px;">BD Bioscience</td>
			<td style="width:133px;">353025</td>
			<td>150-mm cell culture plate&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">19G 1 &#189; syringe needle&#160;</td>
			<td style="width:160px;">BD Bioscience</td>
			<td style="width:133px;">309635</td>
			<td>19G 1 &#189;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Name of Reagent</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">ethanol</td>
			<td>Decon Laboratories, Inc.</td>
			<td>2701</td>
			<td>Decon&#39;s Pure Ethanol 200 Proof</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">collagen solution&#160;</td>
			<td style="width:160px;">BD Bioscience</td>
			<td style="width:133px;">354249</td>
			<td>Collagen I, High Concentration, rat tail, 100 mg</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">trypsin/EDTA</td>
			<td style="width:160px;">Cellgro</td>
			<td style="width:133px;">25-053-CI</td>
			<td><a name="RANGE!D15">0.25% Trypsin-EDTA 1X</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">DMEM</td>
			<td>Life Technologies</td>
			<td>11965-092</td>
			<td>DMEM high glucose (1X), liquid, with L-glutamine, without sodium pyruvate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">10X PBS</td>
			<td style="width:160px;">Affymetrix</td>
			<td style="width:133px;">75889 5 LT</td>
			<td style="width:983px;">PBS, 10X Solution, pH 7.4</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">PFA (paraformaldehyde)</td>
			<td style="width:160px;">Affymetrix</td>
			<td style="width:133px;">19943 1 LT</td>
			<td>4% in PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">FBS</td>
			<td>Sigma-Aldrich</td>
			<td>F4135-500ML</td>
			<td><a name="RANGE!D19">Fetal Bovine Serum</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">EGM2-MV</td>
			<td>Lonza</td>
			<td>CC-3162</td>
			<td>EGM-2 BulletKit, EBM-2 Basal Medium 500 ml and EGM-2 SingleQuot Kit Suppl. &#38; Growth Factors</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td style="width:133px;">T8787</td>
			<td>Triton X-100</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">NaN3</td>
			<td>Sigma-Aldrich</td>
			<td style="width:133px;">S2002-25G</td>
			<td>solubilized in water. 4% stock solution and working concentration is 0.4%.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">mouse anti-human TM4SF1 antibody&#160;</td>
			<td style="width:160px;">Millipore</td>
			<td style="width:133px;">MAB3127</td>
			<td>Epitope is located in extracellular domain</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">mouse anti-human CD9 antibody&#160;</td>
			<td style="width:160px;">BD Bioscience</td>
			<td style="width:133px;">555370</td>
			<td>Epitope is located in extracellular domain</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Alexa Fluor 488 Donkey anti-mouse 2nd antibody</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:133px;">A-21202</td>
			<td>Alexa Fluor 488 Donkey Anti-Mouse IgG (H+L)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Phalloidin</td>
			<td style="width:160px;">Chemicon</td>
			<td style="width:133px;">90324</td>
			<td>Rhodamine-conjugated Phalloidin</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">anti-fade mounting media&#160;</td>
			<td style="width:160px;">Life Technologies</td>
			<td style="width:133px;">P-36931</td>
			<td>ProLong Gold Antifade Reagent with DAPI</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Buffers and solutions</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">70% ethanol&#160;</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td>17.5 ml of ethanol (200 proof) 
			7.5 ml of double deionized water</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">10X PBS (make 200 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">20 ml of 10X PBS</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">180 ml of double deionized water</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">20% Triton X-100 (make 20 ml)&#160;</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">4 ml</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">16 ml double deionized water</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:323px;">4% NaN3 (make 25 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:323px;">1 g of NaN3</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">25 ml of double deionized water</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">50 ng/ml bovine collagen solution in PBS (make 5 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Make stock soln. of 50 &#956;g/ml (50 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">830 &#956;l of Collage I (3 mg)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">50 ml PBS&#160;</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">ICC Blocking Buffer (50 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">49 ml PBS</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td style="width:983px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">2% FBS (add 1 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td style="width:983px;"></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:323px;">0.04% NaN3 (add 100 &#956;l of 4% NaN3)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">ICC Blocking Buffer/0.01% Triton X-100 (make 50 ml)</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">50 ml of ICC Blocking Buffer&#160;</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">25 &#956;l of 20% Triton X-100</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Name of Cell</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">HUVEC&#160;</td>
			<td style="width:160px;">Lonza&#160;</td>
			<td>C2517A</td>
			<td><a href="http://www.lonza.com/products-services/bio-research/primary-and-stem-cells/human-cells-and-media/endothelial-cells-and-media/huvec-human-umbilical-vein-endothelial-cells.aspx">http://www.lonza.com/products-services/bio-research/primary-and-stem-cells/human-cells-and-media/endothelial-cells-and-media/huvec-human-umbilical-vein-endothelial-cells.aspx</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">PC3</td>
			<td style="width:160px;">ATCC</td>
			<td style="width:133px;">CRL-1435</td>
			<td><a href="http://www.atcc.org/products/all/CRL-1435.aspx#85786B46AA23451B94BC5D45200673F7">http://www.atcc.org/products/all/CRL-1435.aspx#85786B46AA23451B94BC5D45200673F7</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Name of Equipment</td>
			<td style="width:160px;"></td>
			<td style="width:133px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">cell culture hood</td>
			<td style="width:160px;">NuAIRE</td>
			<td style="width:133px;">Nu-425-600</td>
			<td>NU-425 (Series 60) BIOLOGICAL SAFETY CABINET&#160;</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:323px;">37 &#176;C, 5% CO2 cell culture incubator&#160;</td>
			<td style="width:160px;">CellStar</td>
			<td style="width:133px;">QWJ300DABA&#160;</td>
			<td>Cellstar CO2 Water Jacketed Incubator</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">heating pad&#160;</td>
			<td>K&#38;H Manufacturing</td>
			<td style="width:133px;">1020</td>
			<td style="width:983px;">K&#38;H Lectro Kennel Heated Pad with Free Fleece Cover (http://www.amazon.com/Lectro-Kennel-Heat-Pad-22-5x28-5-In/dp/B000PSRN20/ref=pd_bxgy_petsupplies_img_y)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">centrifuge</td>
			<td style="width:160px;">Sorvall&#160;</td>
			<td style="width:133px;">T6000B&#160;</td>
			<td>Sorvall T6000 (B) Benchtop Centrifuge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hemacytometer</td>
			<td>Sigma-Aldrich</td>
			<td style="width:133px;">Z359629</td>
			<td>Bright-Line Hemacytometer</td>
		</tr>
	</tbody>
</table>

nanopodia - thin, fragile membrane projections with roles in cell movement and intercellular interactions

Adherent cells in culture maintain a polarized state to support movement and intercellular interactions. Nanopodia are thin, elongated, largely F-actin-negative membrane projections in endothelial and cancer cells that can be visualized through TM4SF1 (Transmembrane-4-L-six-family-1) immunofluorescence staining. TM4SF1 clusters in 100-300 &#956;m diameter TMED (TM4SF1 enriched microdomains) containing 3 to as many as 14 individual TM4SF1 molecules. TMED are arranged intermittently along nanopodia at a regular spacing of 1 to 3 TMED per &#956;m and firmly anchor nanopodia to matrix. This enables nanopodia to extend more than 100 &#956;m from the leading front or trailing rear of polarized endothelial or tumor cells, and causes membrane residues to be left behind on matrix when the cell moves away. TMED and nanopodia have been overlooked because of their extreme fragility and sensitivity to temperature. Routine washing and fixation disrupt the structure. Nanopodia are preserved by direct fixation in paraformaldehyde (PFA) at 37 &#176;C, followed by brief exposure to 0.01% Triton X-100 before staining. Nanopodia open new vistas in cell biology: they promise to reshape our understanding of how cells sense their environment, detect and identify other cells at a distance, initiate intercellular interactions at close contact, and of the signaling mechanisms involved in movement, proliferation, and cell-cell communications. The methods that are developed for studying TM4SF1-derived nanopodia may be useful for studies of nanopodia that form in other cell types through the agency of classic tetraspanins, notably the ubiquitously expressed CD9, CD81, and CD151.

For Step 1:
If cells (such as HUVEC and PC3 used in this study) are able to grow normally, cells will attach to the collagen-coated disc within 30 min after they are seeded, polarize and become mobile soon afterward, and extend nanopodia ahead of their path of movement. Figures 1A and 1B respectively shows a polarized and proliferating HUVEC. Figure 2A shows polarized PC3 cells in a mobile state.
For Step 2:
<p class=...

Watch this Scientific Journal Video about Nanopodia - Thin, Fragile Membrane Projections with Roles in Cell Movement and Intercellular Interactions at JoVE.com

Nanopodia - Thin, Fragile Membrane Projections with Roles in Cell Movement and Intercellular Interactions

Nanopodia are thin but fragile membrane channels that extend up to 100 &#956;m from a cell's leading front or trailing rear and sense the cellular environment. Direct fixation at 37 &#176;C, gentle washing, and avoidance of organic solvents like ethanol, methanol, or acetone and of higher Triton X-100 concentrations are required to observe these cellular structures.

Adherent cells in culture maintain a polarized state to support movement and intercellular interactions. Nanopodia are thin, elongated, largely ...

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