Name: enhancing the engraftment of human induced pluripotent stem cell-derived cardiomyocytes via a transient inhibition of rho kinase activity
Uploaded: 2019-07-10T12:30:00
Description: Watch this Scientific Journal Video about Enhancing the Engraftment of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes via a Transient Inhibition of Rho Kinase Activity at JoVE.com

The authors thank Dr. Joseph C. Wu (Stanford University) for kindly providing the Fluc-GFP construct and Dr. Yanwen Liu for excellent technical assistance. This study is supported by the National Institutes of Health RO1 grants HL95077, HL114120, HL131017, HL138023, UO1 HL134764 (to J.Z.), and HL121206A1 (to L.Z.), and a R56 grant HL142627 (to W.Z.), an American Heart Association Scientist Development Grant 16SDG30410018, and the University of Alabama at Birmingham Faculty Development Grant (to W.Z.).

All animal procedures in this study were approved by the Institutional Animal Care and Use Committee (IACUC) of the University of Alabama at Birmingham and were based on the National Institutes of Health Laboratory Animal Care and Use Guidelines (NIH Publication No 85-23).
1. Preparation of Culture Media and Culture Plates
<ol>
	<li>Medium preparation
	<ol>
		<li>For hiPSC medium, mix 400 mL of human pluripotent stem cell (hPSC) basal medium (Table of Materials 1</st...

<ol>
	<li>Menasche, P., 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=Towards+a+clinical+use+of+human+embryonic+stem+cell-derived+cardiac+progenitors:+a+translational+experience.">Towards a clinical use of human embryonic stem cell-derived cardiac progenitors: a translational experience.</a> European Heart Journal. 36 (12), 743-750 (2015).</li><li>Burridge, P. W., Keller, G., Gold, J. D., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+de+novo+cardiomyocytes:+human+pluripotent+stem+cell+differentiation+and+direct+reprogramming.">Production of de novo cardiomyocytes: human pluripotent stem cell differentiation and direct reprogramming.</a> Cell Stem Cell. 10 (1), 16-28 (2012).</li><li>Frisch, S. M., Francis, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+epithelial+cell-matrix+interactions+induces+apoptosis.">Disruption of epithelial cell-matrix interactions induces apoptosis.</a> Journal of Cell Biology. 124 (4), 619-626 (1994).</li><li>Haun, 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=Identification+of+a+novel+anoikis+signalling+pathway+using+the+fungal+virulence+factor+gliotoxin.">Identification of a novel anoikis signalling pathway using the fungal virulence factor gliotoxin.</a> Nature Communications. 9 (1), 3524 (2018).</li><li>Ohashi, K., 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=Rho-associated+kinase+ROCK+activates+LIM-kinase+1+by+phosphorylation+at+threonine+508+within+the+activation+loop.">Rho-associated kinase ROCK activates LIM-kinase 1 by phosphorylation at threonine 508 within the activation loop.</a> Journal of Biological Chemistry. 275 (5), 3577-3582 (2000).</li><li>Katoh, K., Kano, Y., Noda, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rho-associated+kinase-dependent+contraction+of+stress+fibres+and+the+organization+of+focal+adhesions.">Rho-associated kinase-dependent contraction of stress fibres and the organization of focal adhesions.</a> Journal of The Royal Society Interface. 8 (56), 305-311 (2011).</li><li>Paoli, P., Giannoni, E., Chiarugi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anoikis+molecular+pathways+and+its+role+in+cancer+progression.">Anoikis molecular pathways and its role in cancer progression.</a> Biochimica et Biophysica Acta. 1833 (12), 3481-3498 (2013).</li><li>Legate, K. R., Fassler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+that+regulate+adaptor+binding+to+beta-integrin+cytoplasmic+tails.">Mechanisms that regulate adaptor binding to beta-integrin cytoplasmic tails.</a> Journal of Cell Science. 122 (Pt 2), 187-198 (2009).</li><li>Watanabe, K., 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+ROCK+inhibitor+permits+survival+of+dissociated+human+embryonic+stem+cells.">A ROCK inhibitor permits survival of dissociated human embryonic stem cells.</a> Nature Biotechnology. 25 (6), 681-686 (2007).</li><li>Emre, N., 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+ROCK+inhibitor+Y-27632+improves+recovery+of+human+embryonic+stem+cells+after+fluorescence-activated+cell+sorting+with+multiple+cell+surface+markers.">The ROCK inhibitor Y-27632 improves recovery of human embryonic stem cells after fluorescence-activated cell sorting with multiple cell surface markers.</a> PLoS One. 5 (8), e12148 (2010).</li><li>Ni, Y., Qin, Y., Fang, Z., Zhang, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ROCK+Inhibitor+Y-27632+Promotes+Human+Retinal+Pigment+Epithelium+Survival+by+Altering+Cellular+Biomechanical+Properties.">ROCK Inhibitor Y-27632 Promotes Human Retinal Pigment Epithelium Survival by Altering Cellular Biomechanical Properties.</a> Current Molecular Medicine. 17 (9), 637-646 (2017).</li><li>Laflamme, M. 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=Cardiomyocytes+derived+from+human+embryonic+stem+cells+in+pro-survival+factors+enhance+function+of+infarcted+rat+hearts.">Cardiomyocytes derived from human embryonic stem cells in pro-survival factors enhance function of infarcted rat hearts.</a> Nature Biotechnology. 25 (9), 1015-1024 (2007).</li><li>Zhu, W., Zhao, M., Mattapally, S., Chen, S., Zhang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CCND2+Overexpression+Enhances+the+Regenerative+Potency+of+Human+Induced+Pluripotent+Stem+Cell-Derived+Cardiomyocytes:+Remuscularization+of+Injured+Ventricle.">CCND2 Overexpression Enhances the Regenerative Potency of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Remuscularization of Injured Ventricle.</a> Circulation Research. 122 (1), 88-96 (2018).</li><li>Song, K., 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=Heart+repair+by+reprogramming+non-myocytes+with+cardiac+transcription+factors.">Heart repair by reprogramming non-myocytes with cardiac transcription factors.</a> Nature. 485 (7400), 599-604 (2012).</li><li>Ye, 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=Cardiac+repair+in+a+porcine+model+of+acute+myocardial+infarction+with+human+induced+pluripotent+stem+cell-derived+cardiovascular+cells.">Cardiac repair in a porcine model of acute myocardial infarction with human induced pluripotent stem cell-derived cardiovascular cells.</a> Cell Stem Cell. 15 (6), 750-761 (2014).</li><li>Tohyama, S., 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=Glutamine+Oxidation+Is+Indispensable+for+Survival+of+Human+Pluripotent+Stem+Cells.">Glutamine Oxidation Is Indispensable for Survival of Human Pluripotent Stem Cells.</a> Cell Metabolism. 23 (4), 663-674 (2016).</li><li>Ong, S. G., 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=Microfluidic+Single-Cell+Analysis+of+Transplanted+Human+Induced+Pluripotent+Stem+Cell-Derived+Cardiomyocytes+After+Acute+Myocardial+Infarction.">Microfluidic Single-Cell Analysis of Transplanted Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes After Acute Myocardial Infarction.</a> Circulation. 132 (8), 762-771 (2015).</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=Y-27632+Preconditioning+Enhances+Transplantation+of+Human+Induced+Pluripotent+Stem+Cell-Derived+Cardiomyocytes+in+Myocardial+Infarction+Mice.">Y-27632 Preconditioning Enhances Transplantation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes in Myocardial Infarction Mice.</a> Cardiovascular Research. , (2018).</li><li>Tohyama, S., 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=Distinct+metabolic+flow+enables+large-scale+purification+of+mouse+and+human+pluripotent+stem+cell-derived+cardiomyocytes.">Distinct metabolic flow enables large-scale purification of mouse and human pluripotent stem cell-derived cardiomyocytes.</a> Cell Stem Cell. 12 (1), 127-137 (2013).</li><li>Silginer, M., Weller, M., Ziegler, U., Roth, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrin+inhibition+promotes+atypical+anoikis+in+glioma+cells.">Integrin inhibition promotes atypical anoikis in glioma cells.</a> Cell Death &amp; Disease. 5, e1012 (2014).</li><li>Lelievre, E. 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=N-cadherin+mediates+neuronal+cell+survival+through+Bim+down-regulation.">N-cadherin mediates neuronal cell survival through Bim down-regulation.</a> PLoS One. 7 (3), e33206 (2012).</li><li>Murata, K., 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=Increase+in+cell+motility+by+carbon+ion+irradiation+via+the+Rho+signaling+pathway+and+its+inhibition+by+the+ROCK+inhibitor+Y-27632+in+lung+adenocarcinoma+A549+cells.">Increase in cell motility by carbon ion irradiation via the Rho signaling pathway and its inhibition by the ROCK inhibitor Y-27632 in lung adenocarcinoma A549 cells.</a> Journal of Radiation Research. 55 (4), 658-664 (2014).</li><li>Srivastava, K., Shao, B., Bayraktutan, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PKC-beta+exacerbates+in+vitro+brain+barrier+damage+in+hyperglycemic+settings+via+regulation+of+RhoA/Rho-kinase/MLC2+pathway.">PKC-beta exacerbates in vitro brain barrier damage in hyperglycemic settings via regulation of RhoA/Rho-kinase/MLC2 pathway.</a> Journal of Cerebral Blood Flow &amp; Metabolism. 33 (12), 1928-1936 (2013).</li></ol>

The key steps of this study include obtaining pure hiPSC-CMs, improving the activity of hiPSC-CMs through Y-27632 pretreatment, and finally, transplanting a precise amount of hiPSC-CMs into a mouse MI model.
The key issues addressed here were that, first, we optimized the glucose-free purification methods19 and established a novel efficient purification system. The system procedure included applying cell-dissociation enzymes, replanting cells in gelatin-coated plates, c...

Stem cell-based therapies have shown considerable potential as a treatment for cardiac damage caused by MI1. The use of differentiated hiPSCs provides an inexhaustible source of hiPSC-CMs2 and opens the door for the rapid development of breakthrough treatments. However, many limitations to therapeutic translation remain, including the challenge of the severely low engraftment rate of implanted cells.
Dissociating cells with trypsin initiates anoikis3, which is only accelerated once these cells are injected into harsh environments like the ischemic myocardium, where the hypoxic environment accelerates the course toward cell death. Of the remaining cells, a large proportion is washed out from the implantation site into the bloodstream and spread throughout the periphery. One of the key apoptotic pathways is the RhoA/ROCK pathway4. Based on previous research, the RhoA/ROCK pathway regulates the actin cytoskeletal organization5,6, which is responsible for cell dysfunction7,8. The ROCK inhibitor Y-27632 is widely used during somatic and stem cell dissociation and passaging, to increase cell adhesion and reduce cell apoptosis9,10,11. In this study, Y-27632 is used to treat hiPSC-CMs prior to transplantation in an attempt to increase the cell engraftment rate.
Several methods aimed at improving the cell engraftment rate, such as heat shock and basement membrane matrix coating12, have been established. Aside from these methods, genetic technology can also promote cardiomyocyte proliferation13 or reverse nonmyocardial cells into cardiomyocytes14. From the bioengineering perspective, cardiomyocytes are seeded onto a biomaterial scaffold to improve the transplantation efficiency15. Unfortunately, the majority of these methods are complicated and costly. On the contrary, the method proposed here is simple, cost-efficient, and effective, and it can be used as a basal treatment before transplantation, as well as in conjugation with other technologies.

<table>
	<tbody>
		<tr>
			<td>Reagent</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Accutase (stem cell detachment solution)</td>
			<td>STEMCELL Technologies</td>
			<td>#07920</td>
			<td></td>
		</tr>
		<tr>
			<td>B27 minus insulin</td>
			<td>Fisher Scientific</td>
			<td>A1895601</td>
			<td></td>
		</tr>
		<tr>
			<td>B27 Supplement</td>
			<td>Fisher Scientific</td>
			<td>17-504-044</td>
			<td></td>
		</tr>
		<tr>
			<td>CHIR99021</td>
			<td>Stem Cell Technologies</td>
			<td>72054</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM (1x), high glucose, HEPES, no phenol red</td>
			<td>Thermofisher</td>
			<td>20163029</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Atlanta Biologicals</td>
			<td>S11150</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluo-4 AM (calcium indicator)</td>
			<td>Invitrogen/Thermofisher</td>
			<td>F14201</td>
			<td></td>
		</tr>
		<tr>
			<td>Glucose-free RPMI 1640</td>
			<td>Fisher Scientific</td>
			<td>11879020</td>
			<td></td>
		</tr>
		<tr>
			<td>IWR1</td>
			<td>Stem Cell Technologies</td>
			<td>72562</td>
			<td></td>
		</tr>
		<tr>
			<td>Matrigel (extracellular matrix )</td>
			<td>Fisher Scientific</td>
			<td>CB-40230C</td>
			<td></td>
		</tr>
		<tr>
			<td>mTeSR (human pluripotent stem cells medium)</td>
			<td>STEMCELL Technologies</td>
			<td>85850</td>
			<td></td>
		</tr>
		<tr>
			<td>Pen-strep antibiotic</td>
			<td>Fisher Scientific</td>
			<td>15-140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Pluronic F-127 (surfactant polyol)</td>
			<td>Sigma-Aldrich</td>
			<td>P2443</td>
			<td></td>
		</tr>
		<tr>
			<td>Rho activator II</td>
			<td>Cytoskeleton</td>
			<td>CN03</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI1640</td>
			<td>Fisher Scientific</td>
			<td>11875119</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium DL-lactate</td>
			<td>Sigma-Aldrich</td>
			<td>L4263</td>
			<td></td>
		</tr>
		<tr>
			<td>TrypLE (cell-dissociation enzymes)</td>
			<td>Fisher Scientific</td>
			<td>12-605-010</td>
			<td></td>
		</tr>
		<tr>
			<td>Verapamil</td>
			<td>Sigma-Aldrich</td>
			<td>V4629</td>
			<td></td>
		</tr>
		<tr>
			<td>Y-27632</td>
			<td>STEMCELL Technologies</td>
			<td>72304</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Equipment and Supplies</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>IVIS Lumina III Bioluminescence Instruments</td>
			<td>PerkinElmer</td>
			<td>CLS136334</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mm Coverslips</td>
			<td>Warner</td>
			<td>CS-15R15</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf</td>
			<td>5415R</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal Microscope</td>
			<td>Olympus</td>
			<td>IX81</td>
			<td></td>
		</tr>
		<tr>
			<td>Cryostat</td>
			<td>Thermo Scientific</td>
			<td>NX50</td>
			<td></td>
		</tr>
		<tr>
			<td>Dual Automatic Temperature Controller</td>
			<td>Warner Instruments</td>
			<td>TC-344B</td>
			<td></td>
		</tr>
		<tr>
			<td>Electrophoresis Power Supply</td>
			<td>BIO-RAD</td>
			<td>1645050</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluoresence Microscope</td>
			<td>Olympus</td>
			<td>IX83</td>
			<td></td>
		</tr>
		<tr>
			<td>High Speed Camera</td>
			<td>pco</td>
			<td>1200 s</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser Scan Head</td>
			<td>Olympus</td>
			<td>FV-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Low Profile Open Bath Chamber (mounts into above microincubation system)</td>
			<td>Warner Instruments</td>
			<td>RC-42LP</td>
			<td></td>
		</tr>
		<tr>
			<td>Microincubation System</td>
			<td>Warner Instruments</td>
			<td>DH-40iL</td>
			<td></td>
		</tr>
		<tr>
			<td>Minivent Mouse Ventilator</td>
			<td>Harvard Apparatus</td>
			<td>845</td>
			<td></td>
		</tr>
		<tr>
			<td>NOD/SCID mice</td>
			<td>Jackson Laboratory</td>
			<td>001303</td>
			<td></td>
		</tr>
		<tr>
			<td>Precast Protein Gels</td>
			<td>BIO-RAD</td>
			<td>4561033</td>
			<td></td>
		</tr>
		<tr>
			<td>PVDF Transfer Packs</td>
			<td>BIO-RAD</td>
			<td>1704156</td>
			<td></td>
		</tr>
		<tr>
			<td>Trans-Blot System</td>
			<td>BIO-RAD</td>
			<td>Trans-Blot Turbo</td>
			<td></td>
		</tr>
		<tr>
			<td>Hot bead sterilizer</td>
			<td>Fine Science Tools</td>
			<td>18000-45</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Antibody</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-human Nucleolin (Alexa Fluor 647)</td>
			<td>Abcam</td>
			<td>ab198580</td>
			<td></td>
		</tr>
		<tr>
			<td>Cardiac Troponin T</td>
			<td>R&#38;D Systems</td>
			<td>MAB1874</td>
			<td></td>
		</tr>
		<tr>
			<td>Cardiac Troponin C</td>
			<td>Abcam</td>
			<td>ab137130</td>
			<td></td>
		</tr>
		<tr>
			<td>Cardiac Troponin I</td>
			<td>Abcam</td>
			<td>ab47003</td>
			<td></td>
		</tr>
		<tr>
			<td>Cy5-donkey anti-mouse</td>
			<td>Jackson ImmunoResearch Laboratory</td>
			<td>715-175-150</td>
			<td></td>
		</tr>
		<tr>
			<td>Cy3-donkey anti-rabbit</td>
			<td>Jackson ImmunoResearch Laboratory</td>
			<td>711-165-152</td>
			<td></td>
		</tr>
		<tr>
			<td>Fitc-donkey anti-mouse</td>
			<td>Jackson ImmunoResearch Laboratory</td>
			<td>715-095-150</td>
			<td></td>
		</tr>
		<tr>
			<td>GAPDH</td>
			<td>Abcam</td>
			<td>ab22555</td>
			<td></td>
		</tr>
		<tr>
			<td>Human Cardiac Troponin T</td>
			<td>Abcam</td>
			<td>ab91605</td>
			<td></td>
		</tr>
		<tr>
			<td>Integrin &#946;1</td>
			<td>Abcam</td>
			<td>ab24693</td>
			<td></td>
		</tr>
		<tr>
			<td>Ki67</td>
			<td>EMD Millipore</td>
			<td>ab9260</td>
			<td></td>
		</tr>
		<tr>
			<td>N-cadherin</td>
			<td>Abcam</td>
			<td>ab18203</td>
			<td></td>
		</tr>
		<tr>
			<td>Phospho-Myosin Light Chain 2</td>
			<td>Cell Signaling Technology</td>
			<td>3671s</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Software</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Matlab</td>
			<td>MathWorks</td>
			<td>R2016A</td>
			<td></td>
		</tr>
		<tr>
			<td>Image J</td>
			<td>NIH</td>
			<td>1.52g</td>
			<td></td>
		</tr>
	</tbody>
</table>

enhancing the engraftment of human induced pluripotent stem cell-derived cardiomyocytes via a transient inhibition of rho kinase activity

A crucial factor in improving cellular therapy effectiveness for myocardial regeneration is to safely and efficiently increase the cell engraftment rate. Y-27632 is a highly potent inhibitor of Rho-associated, coiled-coil-containing protein kinase (RhoA/ROCK) and is used to prevent dissociation-induced cell apoptosis (anoikis). We demonstrate that Y-27632 pretreatment for human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs+RI) prior to implantation results in a cell engraftment rate improvement in a mouse model of acute myocardial infarction (MI). Here, we describe a complete procedure of hiPSC-CMs differentiation, purification, and cell pretreatment with Y-27632, as well as the resulting cell contraction, calcium transient measurements, and transplantation into mouse MI models. The proposed method provides a simple, safe, effective, and low-cost method which significantly increases the cell engraftment rate. This method cannot only be used in conjunction with other methods to further enhance the cell transplantation efficiency but also provides a favorable basis for the study of the mechanisms of other cardiac diseases.

The hiPSC-CMs used in this study were derived from human origin with luciferase reporter gene; therefore, the survival rate of the transplanted cells in vivo was detected by bioluminescence imaging (BLI)17 (Figure 1A,B). For histological heart sections, human-specific cardiac troponin T (hcTnT) and human nuclear antigen (HNA) double-positive cells were classified as engrafted hiPSC-CMs (Figure 1C</...

Watch this Scientific Journal Video about Enhancing the Engraftment of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes via a Transient Inhibition of Rho Kinase Activity at JoVE.com

Enhancing the Engraftment of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes via a Transient Inhibition of Rho Kinase Activity

In this protocol, we demonstrate and elaborate on how to use human induced pluripotent stem cells for cardiomyocyte differentiation and purification, and further, on how to improve its transplantation efficiency with Rho-associated protein kinase inhibitor pretreatment in a mouse myocardial infarction model.

A crucial factor in improving cellular therapy effectiveness for myocardial regeneration is to safely and efficiently increase the cell engraftment rate. ...

Our data demonstrates that transient inhibition of Rho-kinase activity enhances adhesion, survival, and engraftment of hiPSC-derived cardiomyocytes after being transplanted into the infarcted animal hearts. We provide a simple, low-cost, while highly efficient method to increase engraftment of transplanted hiPSC-derived cardiomyocytes in the injured animal hearts. As this technique can improve cell engraftment rates safely and efficiently in acute cardiac infarction and heart failure, it contributes for the resulting improvements in cardiac function, vascularities, and apoptosis.Although we only tested our protocols in hiPSCs, these methods can be applied to other types of cells, such as embryonic stem cells, mesenchymal stem cells, et cetera. The dose and duration of Y-27632 treatment is critical. The visual demonstration can demonstrate in great detail all key steps in the protocol, which is beneficial for someone who has never performed this technique before.On day 21 after hiPSC-CM differentiation, aspirate the medium and wash the cells with sterile PBS once. Incubate the cells with 0.5 milliliters of cell-dissociation enzymes per well at 37 degrees Celsius for five to seven minutes. After the incubation time, repeatedly pipette the cell suspension using a one-milliliter pipette in order to thoroughly dissociate the cells.Then, add one milliliter of neutralizing solution to each well, collect the cell mixture in a 15-milliliter centrifuge tube, and centrifuge at 200 times g for three minutes. After the centrifugation, discard the supernatant and resuspend the cells in the neutralizing solution. Then, replant the cells onto gelatin-coated, six-well plates at a density of two million cells per well.After 24 to 48 hours, replace the culture medium with the purification medium for three to five days. Prior to transplantation, culture the cells in the treatment group for 12 hours in RB-plus medium supplemented with 10-micromolar Y-27632. Similarly, perform verapamil treatment on the cells in the RB-plus medium with one micromole of verapamil for 12 hours.After the treatment, wash the hiPSC-CMs with PBS once, and incubate the cells with 0.5 microliters of cell-dissociation enzymes per well for a maximum of two minutes. Repeatedly pipette the cell suspension using a one-milliliter pipette to thoroughly dissociate the cells. Next, neutralize the cells with neutralizing solution, collect the cell mixture in a 15-milliliter centrifuge tube, and centrifuge at 200 times g for three minutes.After centrifugation, resuspend the cells in PBS at a concentration of 0.1 million cells per five microliters in preparation for injection. Immediately following myocardial infarction induction, inject five microliters of control hiPSC-CMs, Y-27632-pretreated hiPSC-CMs, verapamil-treated hiPSC-CMs, or an equal volume of PBS into the mouse's myocardium at each site, one in the infarct area and two in the areas around the infarct. 12 hours before performing calcium transient and contractility detection, add 10-micromolar Y-27632, 100-nanomolar RA, one-micromolar verapamil, or an equal volume of PBS into the culture medium of hiPSC-CMs.Next, discard the medium, and wash the plate with PBS once. Change the medium to a phenol red-free DMEM containing 0.02 weight per volume percent of surfactant polyol, five-micromolar calcium indicator, and the corresponding Y-27632, RA, verapamil, or an equal volume of PBS, and incubate the plate at 37 degrees Celsius for 30 minutes. After the incubation, discard the supernatant, wash the cells with the dye-free DMEM three times, and let the medium rest for 30 minutes to de-esterify the mapping dye.Place the cell-seeded coverslip in an open bath chamber, and insert the chamber into a microincubation system equilibrated to 37 degrees Celsius with an automatic temperature controller. Perfuse it with Tyrode's solution, and continuously add RI, RA, or PBS to the perfusion solution. Use an inverted fluorescence microscope and a laser scanning head to record spontaneous calcium transient by employing an x-t line scan.Record the spontaneous contraction of hiPSC-CMs using the differential interference contrast functionality of the confocal microscope. The survival rate of the transplanted cells was confirmed by the increased luciferase activity. The increased human cardiac troponin T and human nuclear antigen expression showed that Y-27632 pretreatment could significantly improve the cell engraftment rate.Y-27632 pretreated cells exhibited a larger and more defined rod-shaped cytoskeletal structure. Also, Y-27632 pretreatment decreased TUNEL-positive cells, indicating the reduced transplanted hiPSC-CM apoptosis in vivo. Western blot suggested that Y-27632 pretreatment increased expression of integrin beta-1 and N-cadherin and decreased the expression of phospho-myosin light chain 2.This change was normalized 72 hours after Y-27632 withdrawal. In vitro mouse HL-1 cell attachment experiments indicated that Y-27632 pretreatment significantly increased hiPSC-CM adherence relative to HL-1. Y-27632 pretreatment reduced the contractile force, the peak calcium transient fluorescence, and the calcium transient duration.Y-27632 pretreatment regulated cardiomyocyte contraction by significantly reducing the expression of cTnI and cTnT. Similar to Y-27632, verapamil pretreatment increased the luciferase activity and numbers of hcTnT/HNA double-positive cells. The most important step is to culture cells in the treatment group for 12 hours in Rb-plus medium supplemented with 10-micromolar Y-27632.Based on this method, slow release of Y-27632 to further increase the cell engraftment rate is a promising strategy. This technique paves the way for researchers to study the physiology and function of hiPSC of CMs in vivo. The small molecule CHIR99021 used for cardiomyocytes differentiation is hazardous, which may cause respiratory irritation.Please don't intake or inhale by any way.

enhancing-engraftment-human-induced-pluripotent-stem-cell-derived

Research

JoVE Journal

Biochemistry

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

Bacteria are frequently exposed to environmental changes, such as alterations in pH, temperature, redox status, light exposure or mechanical force. Many of these conditions cause protein unfolding in the cell and have detrimental impact on the survival of the organism. A group of unrelated, stress-specific molecular chaperones have been shown to play essential roles in the survival of these stress conditions. While fully folded and chaperone-inactive before stress, these proteins rapidly unfold and become chaperone-active under specific stress conditions. Once activated, these conditionally disordered chaperones bind to a large number of different aggregation-prone proteins, prevent their aggregation and either directly or indirectly facilitate protein refolding upon return to non-stress conditions. The primary approach for gaining a more detailed understanding about the mechanism of their activation and client recognition involves the purification and subsequent characterization of these proteins using in vitro chaperone assays. Follow-up in vivo stress assays are absolutely essential to independently confirm the obtained in vitro results.
This protocol describes in vitro and in vivo methods to characterize the chaperone activity of E. coli HdeB, an acid-activated chaperone. Light scattering measurements were used as a convenient read-out for HdeB&#39;s capacity to prevent acid-induced aggregation of an established model client protein, MDH, in vitro. Analytical ultracentrifugation experiments were applied to reveal complex formation between HdeB and its client protein LDH, to shed light into the fate of client proteins upon their return to non-stress conditions. Enzymatic activity assays of the client proteins were conducted to monitor the effects of HdeB on pH-induced client inactivation and reactivation. Finally, survival studies were used to monitor the influence of HdeB&#39;s chaperone function in vivo.

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

This study describes biophysical, biochemical and molecular techniques to characterize the chaperone activity of Escherichia coli HdeB under acidic pH conditions. These methods have been successfully applied for other acid-protective chaperones such as HdeA and can be modified to work for other chaperones and stress conditions.

Bacteria are frequently exposed to environmental changes, such as alterations in pH, temperature, redox status, light exposure or mechanical force. Many ...

Quantification of Bacterial Histidine Kinase Autophosphorylation Using a Nitrocellulose Binding Assay

We demonstrate a useful method for quantifying autophosphorylation of purified bacterial histidine kinases. Histidine kinases are known for their involvement in two-component signal transduction, a ubiquitous system through which bacteria sense and respond to environmental stimuli. Two-component signaling features autophosphorylation of a histidine kinase, followed by phosphotransfer to the receiver domain of a response regulator protein, which ultimately leads to an output response. Autophosphorylation of the histidine kinase is responsive to the presence of a cognate environmental stimulus, thereby giving bacteria a means to detect and respond to changes in the environment. Despite their importance in bacterial biology, histidine kinases remain poorly understood due to the inherent lability of phosphohistidine. Conventional methods for studying these proteins, such as SDS-PAGE autoradiography, have significant shortcomings. We have developed a nitrocellulose binding assay that can be used to characterize histidine kinases. The protocol for this assay is simple and easy to execute. Our method is higher throughput, less time-consuming, and offers a greater dynamic range than SDS-PAGE autoradiography.

We report and demonstrate an optimized nitrocellulose binding assay that can be used to quantify autophosphorylation of purified bacterial histidine kinases. Our method has several advantages over traditional SDS-PAGE based techniques, providing a valuable alternative for characterizing these important proteins.

We demonstrate a useful method for quantifying autophosphorylation of purified bacterial histidine kinases. Histidine kinases are known for their ...

Assaying Protein Kinase Activity with Radiolabeled ATP

Protein kinases are able to govern large-scale cellular changes in response to complex arrays of stimuli, and much effort has been directed at uncovering allosteric details of their regulation. Kinases comprise signaling networks whose defects are often hallmarks of multiple forms of cancer and related diseases, making an assay platform amenable to manipulation of upstream regulatory factors and validation of reaction requirements critical in the search for improved therapeutics. Here, we describe a basic kinase assay that can be easily adapted to suit specific experimental questions including but not limited to testing the effects of biochemical and pharmacological agents, genetic manipulations such as mutation and deletion, as well as cell culture conditions and treatments to probe cell signaling mechanisms. This assay utilizes radiolabeled [&#947;-32P] ATP, which allows for quantitative comparisons and clear visualization of results, and can be modified for use with immunoprecipitated or recombinant kinase, specific or typified substrates, all over a wide range of reaction conditions.

Protein kinases are highly evolved signaling enzymes and scaffolds that are critical for inter- and intracellular signal transduction. We present a protocol for measuring kinase activity through the use of radiolabeled adenosine triphosphate ([&#947;-32P] ATP), a reliable method to aid in elucidation of cellular signaling regulation.

Protein kinases are able to govern large-scale cellular changes in response to complex arrays of stimuli, and much effort has been directed at uncovering ...

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Cyclin-dependent kinase 1 (Cdk1) is a master controller for the cell cycle in all eukaryotes and phosphorylates an estimated 8 - 13% of the proteome; however, the number of identified targets for Cdk1, particularly in human cells is still low. The identification of Cdk1-specific phosphorylation sites is important, as they provide mechanistic insights into how Cdk1 controls the cell cycle. Cell cycle regulation is critical for faithful chromosome segregation, and defects in this complicated process lead to chromosomal aberrations and cancer.
Here, we describe an in vitro kinase assay that is used to identify Cdk1-specific phosphorylation sites. In this assay, a purified protein is phosphorylated in vitro by commercially available human Cdk1/cyclin B. Successful phosphorylation is confirmed by SDS-PAGE, and phosphorylation sites are subsequently identified by mass spectrometry. We also describe purification protocols that yield highly pure and homogeneous protein preparations suitable for the kinase assay, and a binding assay for the functional verification of the identified phosphorylation sites, which probes the interaction between a classical nuclear localization signal (cNLS) and its nuclear transport receptor karyopherin &#945;. To aid with experimental design, we review approaches for the prediction of Cdk1-specific phosphorylation sites from protein sequences. Together these protocols present a very powerful approach that yields Cdk1-specific phosphorylation sites and enables mechanistic studies into how Cdk1 controls the cell cycle. Since this method relies on purified proteins, it can be applied to any model organism and yields reliable results, especially when combined with cell functional studies.

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Cyclin-dependent kinase 1 (Cdk1) is activated in the G2 phase of the cell cycle and regulates many cellular pathways. Here, we present a protocol for an in vitro kinase assay with Cdk1, which allows the identification of Cdk1-specific phosphorylation sites for establishing cellular targets of this important kinase.

Cyclin-dependent kinase 1 (Cdk1) is a master controller for the cell cycle in all eukaryotes and phosphorylates an estimated 8 - 13% of the proteome; ...

Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition

Oxygen-sensitive proteins, including those enzymes which utilize oxygen as a substrate, can have reduced stability when purified using traditional aerobic purification methods. This manuscript illustrates the technical details involved in the anaerobic purification process, including the preparation of buffers and reagents, the methods for column chromatography in a glove box, and the desalting of the protein prior to kinetics. Also described are the methods for preparing and using an oxygen electrode to perform kinetic characterization of an oxygen-utilizing enzyme. These methods are illustrated using the dioxygenase enzyme DesB, a gallate dioxygenase from the bacterium Sphingobium sp. strain SYK-6.

Here we present a protocol for anaerobic protein purification, anaerobic protein concentration, and subsequent kinetic characterization using an oxygen electrode system. The method is illustrated using the enzyme DesB, a dioxygenase enzyme which is more stable and active when purified and stored in an anaerobic environment.

Oxygen-sensitive proteins, including those enzymes which utilize oxygen as a substrate, can have reduced stability when purified using traditional aerobic ...

Human Peripheral Blood Neutrophil Isolation for Interrogating the Parkinson's Associated LRRK2 Kinase Pathway by Assessing Rab10 Phosphorylation

The leucine rich repeat kinase 2 (LRRK2) is the most frequently mutated gene in hereditary Parkinson&#8217; disease (PD) and all pathogenic LRRK2 mutations result in hyperactivation of its kinase function. Here, we describe an easy and robust assay to quantify LRRK2 kinase pathway activity in human peripheral blood neutrophils by measuring LRRK2-controlled phosphorylation of one of its physiological substrates, Rab10 at threonine 73. The immunoblotting analysis described requires a fully selective and phosphospecific antibody that recognizes the Rab10 Thr73 epitope phosphorylated by LRRK2, such as the MJFF-pRab10 rabbit monoclonal antibody. It uses human peripheral blood neutrophils, because peripheral blood is easily accessible and neutrophils are an abundant and homogenous constituent. Importantly, neutrophils express relatively high levels of both LRRK2 and Rab10. A potential drawback of neutrophils is their high intrinsic serine protease activity, which necessitates the use of very potent protease inhibitors such as the organophosphorus neurotoxin diisopropylfluorophosphate (DIFP) as part of the lysis buffer. Nevertheless, neutrophils are a valuable resource for research into LRRK2 kinase pathway activity in vivo and should be considered for inclusion into PD biorepository collections.

Mutations in the leucine rich repeat kinase 2 gene (LRRK2) cause hereditary Parkinson&#8217;s disease. We have developed an easy and robust method for assessing LRRK2-controlled phosphorylation of Rab10 in human peripheral blood neutrophils. This may help identify individuals with increased LRRK2 kinase pathway activity.

The leucine rich repeat kinase 2 (LRRK2) is the most frequently mutated gene in hereditary Parkinson&#8217; disease (PD) and all pathogenic LRRK2 ...

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets in both physiological and pathological states. CK2 is an evolutionarily conserved serine/threonine kinase with a growing list of hundreds of substrates involved in multiple cellular processes. Due to its pleiotropic properties, identifying and characterizing a comprehensive set of CK2 substrates has been particularly challenging and remains a hurdle in the study of this important enzyme. To address this challenge, we have devised a versatile experimental strategy that enables the targeted enrichment and identification of putative CK2 substrates. This protocol takes advantage of the unique dual co-substrate specificity of CK2 allowing for specific thiophosphorylation of its substrates in a cell or tissue lysate. These substrate proteins are subsequently alkylated, immunoprecipitated, and identified by liquid chromatography/tandem mass spectrometry (LC-MS/MS). We have previously used this approach to successfully identify CK2 substrates from Drosophila ovaries and here we extend the application of this protocol to human glioblastoma cells, illustrating the adaptability of this method to investigate the biological roles of this kinase in various model organisms and experimental systems.

The objective of this protocol is to label, enrich, and identify substrates of protein kinase CK2 from a complex biological sample such as a cell lysate or tissue homogenate. This method leverages unique aspects of CK2 biology for this purpose.

The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets ...

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle

Protein kinase RNA-activated (PKR) is a member of the innate immune response proteins and recognizes the double-stranded secondary structure of viral RNAs. When bound to viral double-stranded RNAs (dsRNAs), PKR undergoes dimerization and subsequent autophosphorylation. Phosphorylated PKR (pPKR) becomes active and induces phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2&#945;) to suppress global translation. Increasing evidence suggests that PKR can be activated under physiological conditions such as during the cell cycle or under various stress conditions without infection. However, our understanding of the RNA activators of PKR is limited due to the lack of a standardized experimental method to capture and analyze PKR-interacting dsRNAs. Here, we present an experimental protocol to specifically enrich and analyze PKR bound RNAs during the cell cycle using HeLa cells. We utilize the efficient crosslinking activity of formaldehyde to fix PKR-RNA complexes and isolate them via immunoprecipitation. PKR co-immunoprecipitated RNAs can then be further processed to generate a high-throughput sequencing library. One major class of PKR-interacting cellular dsRNAs is mitochondrial RNAs (mtRNAs), which can exist as intermolecular dsRNAs through complementary interaction between the heavy-strand and the light-strand RNAs. To study the strandedness of these duplex mtRNAs, we also present a protocol for strand-specific qRT-PCR. Our protocol is optimized for the analysis of PKR-bound RNAs, but it can be easily modified to study cellular dsRNAs or RNA-interactors of other dsRNA binding proteins.

We present experimental approaches for studying RNA-interactors of double-stranded RNA binding protein kinase RNA-activated (PKR) during the mammalian cell cycle using HeLa cells. This method utilizes formaldehyde to crosslink RNA-PKR complexes and immunoprecipitation to enrich PKR-bound RNAs. These RNAs can be further analyzed through high-throughput sequencing or qRT-PCR.

Protein kinase RNA-activated (PKR) is a member of the innate immune response proteins and recognizes the double-stranded secondary structure of viral ...

Single-Step Enrichment of a TAP-Tagged Histone Deacetylase of the Filamentous Fungus Aspergillus nidulans for Enzymatic Activity Assay

Class 1 histone deacetylases (HDACs) like RpdA have gained importance as potential targets for treatment of fungal infections and for genome mining of fungal secondary metabolites. Inhibitor screening, however, requires purified enzyme activities. Since class 1 deacetylases exert their function as multiprotein complexes, they are usually not active when expressed as single polypeptides in bacteria. Therefore, endogenous complexes need to be isolated, which, when conventional techniques like ion exchange and size exclusion chromatography are applied, is laborious and time consuming. Tandem affinity purification has been developed as a tool to enrich multiprotein complexes from cells and thus turned out to be ideal for the isolation of endogenous enzymes. Here we provide a detailed protocol for the single-step enrichment of active RpdA complexes via the first purification step of C-terminally TAP-tagged RpdA from Aspergillus nidulans. The purified complexes may then be used for the subsequent inhibitor screening applying a deacetylase assay. The protein enrichment together with the enzymatic activity assay can be completed within two days.

Single-Step Enrichment of a TAP-Tagged Histone Deacetylase of the Filamentous Fungus Aspergillus nidulans for Enzymatic Activity Assay

Class 1 histone deacetylases (HDACs) like RpdA have gained importance as potential targets to treat fungal infections. Here we present a protocol for the specific enrichment of TAP-tagged RpdA combined with an HDAC activity assay that allows in vitro efficacy testing of histone deacetylase inhibitors.

Class 1 histone deacetylases (HDACs) like RpdA have gained importance as potential targets for treatment of fungal infections and for genome mining of ...

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important roles for the cell and may unravel new cellular processes. Among proteins, kinases are major actors as they belong to cell signaling pathways and have the ability to switch on or off many processes crucial to the fate of the cell, such as cell growth, division, differentiation, motility, and death.
In this study, we focused on a new potential kinase protein, LIMK2-1. We demonstrated its existence by Western Blot using a specific antibody. We evaluated its interaction with an upstream regulating protein using coimmunoprecipitation experiments. Coimmunoprecipitation is a very powerful technique able to detect the interaction between two target proteins. It may also be used to detect new partners of a bait protein. The bait protein may be purified either via a tag engineered to its sequence or via an antibody specifically targeting it. These protein complexes may then be separated by SDS-PAGE (Sodium Dodecyl Sulfate PolyAcrylamide Gel) and identified using mass spectrometry. Immunoprecipitated LIMK2-1 was also used to test its kinase activity in vitro by &#947;[32P] ATP labeling. This well-established assay may use many different substrates, and mutated versions of the bait may be used to assess the role of specific residues. The effects of pharmacological agents may also be evaluated since this technique is both highly sensitive and quantitative. Nonetheless, radioactivity handling requires particular caution. Kinase activity may also be assessed with specific antibodies targeting the phospho group of the modified amino acid. These kinds of antibodies are not commercially available for all the phospho modified residues.

We characterized a new kinase protein using robust biochemical approaches: Western Blot analysis with a dedicated specific antibody on different cell lines and tissues, interactions by coimmunoprecipitation experiments, kinase activity detected by Western Blot using a phospho-specific antibody and by &#947;[32P] ATP labeling.

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important ...