We thank Dr. Shahragim Tajbakhsh for providing Myf5+/nLacZ mice. We also thank Alexander Hron and Michael Baumrucker for critical reading of this manuscript. This work was supported by grants from the Muscular Dystrophy Association (MDA) and Gregory Marzolf Jr. MD Center Award.

The animals were housed in an SPF environment and were monitored by the Research Animal Resources (RAR) of the University of Minnesota. The animals were euthanized by appropriate means (CO2&#160;inhalation or KCl injection after being anesthetized with IP injection of Avertin (250 mg/kg). All protocols were approved by the Institutional Animal Care and Use Committee (IACUC, Code Number: 1304-30492) of the University of Minnesota.
1. Isolation of Mononuclear Cells from Mouse Skeletal Muscle
<ol>
	<li>Properly sacrifice 1 or 2 young adult mice (3-8 weeks).
	<ol>
		<li>Pinch and slit the skin of the abdomen with sharp scissors. Peel off skin to completely show triceps and hind limb muscle (pull the skin in opposing directions).</li>
		<li>Remove all leg skeletal muscles (tibialis anterior, gastrocnemius, and quadriceps) and triceps along the bones with scissors. Then transfer muscles to ice-cold, sterile PBS in a 10 cm plate.</li>
	</ol>
	</li>
	<li>Wash blood off muscles in PBS and transfer muscles to a new sterile 6 cm plate: 1 plate for 1-2 mice.</li>
	<li>Remove connective tissue, blood vessels, nerve bundles, and adipogenic tissue under a dissection microscope.</li>
	<li>Using scissors for ophthalmology, cut and mince the tissue into a smooth pulp (Figures&#160;1A and 1B). Try not to leave large pieces, as they will not be broken down readily by the enzyme solution.</li>
	<li>Transfer minced muscles into a Falcon 50 ml tube, and add 5 ml of collagenase solution (0.2% collagenase Type 2 in 10% FBS in DMEM). Incubate at 37 &#176;C for 60 min.</li>
	<li>Triturate (up and down with an 18 G needle) to homogenize mixture (Figure&#160;1C). Then further incubate the mixture at 37 &#176;C for 15 min.</li>
	<li>Triturate again to homogenize mixture to dissociate into single cell suspension. Add 2% FBS in DMEM up to 50 ml into the single cell suspension and mix well.</li>
	<li>Place a cell strainer (70 &#956;m) onto a Falcon 50 ml tube (Figure&#160;1D). Transfer the supernatant containing the dissociated cells onto a cell strainer, and pipette the cell suspension up and down on the filter until it passes through.</li>
	<li>Count cell number by hemocytometer. Centrifuge the tubes at 2,000 rpm at 4 &#176;C for 5 min; aspirate and discard the supernatant.</li>
	<li>Resuspend with 10 ml of 2% FBS in DMEM. Centrifuge the tubes at 2,000 rpm at 4 &#176;C for 5 min; aspirate and discard the supernatant.</li>
	<li>Resuspend with 200 &#956;l of 2% FBS in DMEM and transfer cell suspension into 1.5 ml microcentrifuge tubes. Usually, about 2 x 106 cells should be harvested from muscles of 1 mouse. Cells will be diluted to a concentration of 1 x 106 cells in 100 &#956;l of 2% FBS in DMEM.</li>
</ol>
2. Antibody Staining and Separation with MACS
During the following procedures, maintain sterile conditions by using sterile buffers. Each volume of antibodies added and cell suspension medium is calculated for cells from whole muscles of 1 mouse. If cells are harvested from 2 or more mice, the amount of reagents should be optimized.
<ol>
	<li>Add 1 &#956;l each of CD31-PE, CD45-PE, Sca-1-PE, and Integrin &#945;7 antibody into 200 &#956;l of the cell suspension. Incubate on ice for 30 min.</li>
	<li>Wash cells: After incubation, add 1 ml of 2% FBS in DMEM into the cell suspension in the 1.5 ml tube, and centrifuge at 2,000 rpm at 4 &#176;C for 3 min. Repeat this step twice.</li>
	<li>Aspirate and discard the supernatant.</li>
	<li>Resuspend cells with 200 &#956;l of 2% FBS in DMEM, and add 10 &#956;l of Anti-PE Magnetic Beads. Incubate on ice for 30 min.</li>
	<li>Wash cells: After incubation, add 1 ml of MACS buffer to the cell suspension in the 1.5 ml microcentrifuge tube, and then centrifuge at 2,000 rpm at 4 &#176;C for 3 min. Repeat this step twice. Note that cells should be washed by MACS buffer before being separated by magnetic column.</li>
	<li>Aspirate and discard the supernatant. Resuspend the cells with 1.0 ml of MACS buffer.</li>
	<li>Set up LD column on a Magnetic board, and rinse the column with 2.0 ml of MACS buffer (Figure&#160;1E).</li>
	<li>Transfer the cell suspension onto the LD column, and collect the flow-through fraction into a 1.5 ml tube. This fraction contains PE-negative cells.</li>
	<li>Centrifuge at 2,000 rpm at 4 &#176;C for 3 min, aspirate and discard the supernatant.</li>
	<li>Resuspend cells with 200 &#956;l of 2% FBS in DMEM, and add 10 &#956;l of Anti-Mouse IgG Magnetic Beads. Incubate on ice for 30 min.</li>
	<li>Wash cells: After incubation, add 1 ml of MACS buffer into the cell suspension in 1.5 ml tube, and then centrifuge at 2,000 rpm at 4 &#176;C for 3 min. Aspirate and discard the supernatant. Repeat this step twice. Resuspend cells with 500 &#956;l of MACS buffer.</li>
	<li>Set up MS column on a Magnetic board, and rinse the column with 500&#160;&#956;l&#160;of MACS buffer (Figure&#160;1F).</li>
	<li>Transfer suspended cell solution onto the MS column, and discard the flow-through fraction (Integrin &#945;7-negative cells).</li>
	<li>Rinse with 1 ml of MACS buffer, and repeat this step twice.</li>
	<li>After rinsing, remove column from the magnetic field of separator. Apply 1.0 ml of MACS buffer onto the column, and elute the magnetically labeled cells (Integrin &#945;7-positive cells) into a 1.5 ml microcentrifuge tube by pushing the syringe plunger from the top of the column. Collect the flow-through into a 1.5 ml tube. Repeat the elution with 1.5 ml of MACS buffer and collect the flow-through.</li>
	<li>Centrifuge at 2,000 rpm at 4 &#176;C for 3 min, aspirate and discard the supernatant.</li>
	<li>Resuspend purified cells with 1 ml of Myoblast medium (20% FBS contained Hams F-10 with bFGF), and plate cells on Matrigel-coated 10 cm plate with 8 ml of Myoblast Medium (5 ml in 6 cm plate) (Figure&#160;1G). Note that 1-2 x 105 cells can potentially be isolated from 1 intact mouse muscle.</li>
</ol>
3. Maintenance
<ol>
	<li>Feed cells every other day with Myoblast medium. The appearance of growing myoblasts is of a small and round shape expressing MyoD (Figure&#160;2) and Pax7 (data not shown) in their nucleus.</li>
	<li>Myoblasts should be passaged before 50% confluence or when starting cell fusion. After rinsing once with PBS, incubate cells with 0.25% Trypsin solution at 37 &#176;C for 3 min in a CO2 incubator and collect dissociated cells with Myoblast medium. After centrifuge cells (1,000 rpm for 5 min), suspend with Myoblast medium and replate cells onto new Matrigel-coated plates. Collagen-coated plates can be used after passage 3. One plate can usually be split into three to five plates.</li>
</ol>
4. Differentiation
<ol>
	<li>Refeed with Differentiation Medium every other day.</li>
	<li>By day 1 in Differentiation Medium, myoblasts exit the cell cycle and undergo differentiation into myosin heavy chain (MHC)-positive myocytes. These myoctyes begin cell fusion with each other to generate multinucleated myotubes. Typically, most myoblasts become MHC-positive differentiating mononuclear myocytes or myotubes (Figure&#160;2) by day 3-5 in Differentiation Medium.</li>
</ol>
5. Myoblast Transplantation into Mouse for Skeletal Muscle Regeneration
<ol>
	<li>Anaesthetize the mouse with Avertin (250 mg/kg) by intraperitoneal (IP) injection.</li>
	<li>Shave the skin hair around on tibialis anterior (TA) muscle. Twenty-four hours before myoblast transplantation, 10 &#956;M CTX (50 &#956;l) is intramuscularly injected into the Nod/Scid mouse TA muscle to induce muscle regeneration via a 31 G insulin syringe through shaved skin (Figure&#160;3).</li>
	<li>Proliferating myoblasts are dissociated with 0.25% Trypsin solution, and centrifuged at 1,000 rpm for 5 min. Aspirate and discard the supernatant. Resuspend 1 x 106 cells with 50 &#956;l of 2% FBS in DMEM. Transfer the suspended cells into a 31 G insulin syringe.</li>
	<li>Recipient mice will be anaesthetized with Avertin (250 mg/kg) by IP injection, and the 1 x 106 myoblasts (Figure&#160;2) are intramuscularly injected into regenerating TA muscle.</li>
	<li>Harvest TA muscle by 1-4 weeks after cell injection for histological analysis (Figure&#160;3).</li>
</ol>

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No conflict of interest declared.

In this protocol, quiescent satellite cells can be easily purified from adult skeletal muscle of mice by collagenase digestion and surface antibody-mediated MACS separation. This method takes approximately 6 hours and does not need any expensive equipment such as a FACS machine. In addition, this method is relatively inexpensive compared to surface antibody-mediated FACS separation. A higher yield of quiescent satellite cells is also expected in comparison to FACS for this method since FACS laser exposure tends to induce...

Muscle satellite cells are a small population of myogenic stem cells located beneath the basal lamina of skeletal muscle fibers. They are characterized by the expression of Pax7, Pax3, c-Met, M-cadherin, CD34, Syndecan-3, and calcitonin1-3. Satellite cells have proven to be responsible for muscle regeneration as muscle stem cells. In adult muscle, satellite cells are normally mitotically quiescent4-8. Following injury, satellite cells are activated, initiate expression of MyoD, and enter the cell cycle to expand their progeny, termed myogenic precursor cells or myoblasts3. After several rounds of cell division, myoblasts exit the cell cycle and fuse to each other in order to undergo differentiation into multi-nucleated myotubes, followed by mature muscle fibers. Myoblasts isolated from adult muscle can readily be expanded ex vivo. The capacity for myoblasts to become muscle fibers in regenerating muscle and to form ectopic muscle fibers in nonmuscle tissues is exploited by myoblast transplantation, a potential therapeutic approach for Duchenne muscular dystrophy (DMD)4, urological dysfunction9, and heart failure10. Indeed, myoblasts have been successfully transplanted in the muscle of both mdx (DMD model) mice and DMD patients11-14. The injected normal myoblasts fuse with host muscle fibers to improve the histology and function of the diseased muscle. Previous work demonstrated that subpopulations of myoblasts are more stem cell-like and remain in an undifferentiated state longer in muscle during muscle regeneration5. Recent work has shown that freshly isolated satellite cells from adult muscle contain a stem cell-like population that exhibits more efficient engraftment and self-renewal activity in regenerating muscle5-8. Therefore, purification of a pure population of quiescent satellite cells from adult skeletal muscle is essential for understanding the biology of satellite cells, myoblasts and muscle regeneration, and for the development of cell-based therapies.
However, current prospective purification methods of quiescent satellite cells require the use of an expensive fluorescence-activated cell sorting (FACS) machine1,2,6-8. In addition, FACS laser exposure tends to induce cell death during separation, which causes lower yield of quiescent satellite cells15. Here, we present a new method for the rapid, economical, and reliable purification of quiescent satellite cells from adult mouse skeletal muscle. This method utilizes enzymatic dissociation followed by magnetic-activated cell sorting (MACS). Following isolation of pure quiescent satellite cells, these cells can be cultured to obtain large numbers of myoblasts after several passages. We also show that intramuscular injection of these freshly isolated quiescent satellite cells or ex vivo expanded myoblasts can be transplanted into cardiotoxin (CTX)-induced regenerating mouse skeletal muscle to examine the contribution of donor-derived cells to regenerating muscle fibers, as well as to satellite cell compartments for the examination of self-renewal activities.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Materials</td>
		</tr>
		<tr>
			<td>Collagenase Type 2</td>
			<td>Worthington</td>
			<td>CLS-2</td>
			<td>100 mg</td>
		</tr>
		<tr>
			<td>Marigel</td>
			<td>BD Biosciences</td>
			<td>356234</td>
			<td>5 ml</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Gibco-Invitrogen</td>
			<td>10569010</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>Collagen (Rat Tail)</td>
			<td>BD Biosciences</td>
			<td>354236</td>
			<td>100 mg (3-4 mg/ml)</td>
		</tr>
		<tr>
			<td>Acetic Acid</td>
			<td>Sigma-Aldrich</td>
			<td>320099-500ML</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>bFGF, human, Recombinant</td>
			<td>Gibco-Invitrogen</td>
			<td>PHG0263</td>
			<td>1 mg</td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>Sigma-Aldrich</td>
			<td>A5611-1G</td>
			<td>1 g</td>
		</tr>
		<tr>
			<td>Ham&#8217;s F10 Medium</td>
			<td>Gibco-Invitrogen</td>
			<td>11550-043</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Fisher Scientific</td>
			<td>3600511</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>Horse Serum</td>
			<td>Gibco-Invitrogen</td>
			<td>26050088</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>Penicillin/Streptmycin</td>
			<td>Gibco-Invitrogen</td>
			<td>15640055</td>
			<td>100 ml</td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline</td>
			<td>Gibco-Invitrogen</td>
			<td>14190144</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>0.25% Trypsin/EDTA</td>
			<td>Gibco-Invitrogen</td>
			<td>25200072</td>
			<td>500 ml</td>
		</tr>
		<tr>
			<td>18G needle with 12cc Syringe</td>
			<td>Fisher Scientific</td>
			<td>22-256-563</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell strainer (70 &#956;m)</td>
			<td>Fisher Scientific</td>
			<td>22-363-548</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon 50 ml tube</td>
			<td>BD Biosciences</td>
			<td>352098</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon 15 ml tube</td>
			<td>BD Biosciences</td>
			<td>352097</td>
			<td></td>
		</tr>
		<tr>
			<td>10 cm tissue culture plate</td>
			<td>BD Biosciences</td>
			<td>353003</td>
			<td></td>
		</tr>
		<tr>
			<td>6 cm tissue culture plate</td>
			<td>BD Biosciences</td>
			<td>353004</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon 10 ml disposable pipet</td>
			<td>BD Biosciences</td>
			<td>357551</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-CD31 antibody-PE</td>
			<td>eBiosciences</td>
			<td>12-0311</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-CD45 antibody-PE</td>
			<td>eBiosciences</td>
			<td>30-F11</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Sca1 antibody-PE</td>
			<td>eBiosciences</td>
			<td>Dec-81</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Integrin &#945;7 antibody</td>
			<td>MBL International</td>
			<td>ABIN487462</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-PE MicroBeads</td>
			<td>Miltenyi Biotec</td>
			<td>130-048-801</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Mouse IgG MicroBeads</td>
			<td>Miltenyi Biotec</td>
			<td>130-048-402</td>
			<td></td>
		</tr>
		<tr>
			<td>Mini &#38; MidiMACS Starting Kit</td>
			<td>Miltenyi Biotec</td>
			<td>130-091-632</td>
			<td></td>
		</tr>
		<tr>
			<td>MS Column</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-201</td>
			<td></td>
		</tr>
		<tr>
			<td>LD Column</td>
			<td>Miltenyi Biotec</td>
			<td>130-042-901</td>
			<td></td>
		</tr>
		<tr>
			<td>Cardiotoxin</td>
			<td>Sigma Aldrich</td>
			<td>C9759-1MG</td>
			<td>Stock 10 &#956;M in PBS</td>
		</tr>
		<tr>
			<td>31G Insulin syringe</td>
			<td>BD Biosciences</td>
			<td>328438</td>
			<td></td>
		</tr>
		<tr>
			<td>Refrigerated Microcentrifuge (Microfuge 22R)</td>
			<td>Beckman Coulter</td>
			<td>368826</td>
			<td></td>
		</tr>
		<tr>
			<td>S241.5 Swinging Bucket Rotor</td>
			<td>Beckman Coulter</td>
			<td>368882</td>
			<td></td>
		</tr>
		<tr>
			<td>Refrigerated Centrifuge (Allegra X-22R)</td>
			<td>Beckman Coulter</td>
			<td>392187</td>
			<td></td>
		</tr>
		<tr>
			<td>Nod/Scid immunodeficient mice</td>
			<td>Charles River Laboratories</td>
			<td>Strain Code 394</td>
			<td>Use 2 months old mice</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Reagents</td>
		</tr>
		<tr>
			<td>Name of the reagent</td>
			<td></td>
			<td></td>
			<td>Recipie</td>
		</tr>
		<tr>
			<td>10% and 2% FBS DMEM</td>
			<td></td>
			<td></td>
			<td>DMEM (Gibco-Invitrogen #10569010) with 10% or 2% FBS (Fisher Scientific #03600511) and 1% Penicillin/Streptomycin (Gibco-Invitrogen #15640055).</td>
		</tr>
		<tr>
			<td>0.2% Collagenase solution</td>
			<td></td>
			<td></td>
			<td>Collagenase Type 2 (Worthington, #CLS-2), Stock: 50 ml: 100 mg Collagenase Type 2 in 10% FBS DMEM.</td>
		</tr>
		<tr>
			<td>10% Matrigel solution</td>
			<td></td>
			<td></td>
			<td>Matrigel (BD Biosciences: #356234) is placed on ice for thawing overnight. Five ml Matrigel is dilute by 45 ml DMEM and 5 ml aliquots are stored at -20&#176;C until use.</td>
		</tr>
		<tr>
			<td>Matrigel-coated plate</td>
			<td></td>
			<td></td>
			<td>Five ml of 10% Matrigel solution is placed on ice for thawing and is used for coating 10 cm plate at room temprature for 1 minutes. The plate is placed in 5% CO2 incubator at 37&#176;C for 30 minute after removing Matrigel solution, and let the plate dry in culture hood for another 30 minutes. Removed 10% Matrigel solution is stored at -20&#176;C for reusing.</td>
		</tr>
		<tr>
			<td>0.01% Collagen solution</td>
			<td></td>
			<td></td>
			<td>Mix to final: 0.01% Collagen (Collagen, Rat Tail: BD Biosciences #354236) in 0.2% acetic acid (320099-500ML) in ddH2O.</td>
		</tr>
		<tr>
			<td>Collagen-coated plate</td>
			<td></td>
			<td></td>
			<td>Add 5 ml or 2 ml of Collagen solution to a 10 cm or 6 cm tissue culture plate and let sit at room temperature for three hours. Then, aspirate off liquid and allow to dry in culture hood for 30 min to overnight. Plates can be stored at room temperature for several months.</td>
		</tr>
		<tr>
			<td>bFGF stock solution</td>
			<td></td>
			<td></td>
			<td>bFGF, Human, Recombinant (Gibco-Invitrogen #PHG0263, 1 mg) is dissolved with 0.1% BSA solution consisting of 1 mg BSA (Sigma-Aldrich #A5611-1G) and 2 ml ddH2O (0.5 mg/ml bFGF). Aliquot 20 &#956;l in 500 &#956;l microcentrifuge tubes and kept in -80&#176;C.</td>
		</tr>
		<tr>
			<td>Myoblast medium</td>
			<td></td>
			<td></td>
			<td>500 mL HAM&#8217;S F10 Medium (Gibco-Invitrogen #11550-043) supplemented with 20% FBS (Fisher Scientific #03600511), Penicillin/streptomycin (Gibco-Invitrogen #15640055), and 10 &#956;g of bFGF (20 &#956;l of bFGF stock).</td>
		</tr>
		<tr>
			<td>Differentiation medium</td>
			<td></td>
			<td></td>
			<td>500 mL DMEM (Gibco-Invitrogen #10569010) supplemented with 5% Horse serum (Gibco-Invitrogen #26050088) and 1% Penicillin/streptomycin (Gibco-Invitrogen #15640055).</td>
		</tr>
		<tr>
			<td>10 &#956;M Cardiotoxin stock</td>
			<td></td>
			<td></td>
			<td>1 mg Cardiotoxin (EMD Millipore #217504-1MG) is dissolved with 13.9 ml PBS.</td>
		</tr>
	</tbody>
</table>

isolation, culture, and transplantation of muscle satellite cells

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal nuclei in muscle fibers. In adult muscle, satellite cells are normally mitotically quiescent. Following injury, however, satellite cells initiate cellular proliferation to produce myoblasts, their progenies, to mediate the regeneration of muscle. Transplantation of satellite cell-derived myoblasts has been widely studied as a possible therapy for several regenerative diseases including muscular dystrophy, heart failure, and urological dysfunction. Myoblast transplantation into dystrophic skeletal muscle, infarcted heart, and dysfunctioning urinary ducts has shown that engrafted myoblasts can differentiate into muscle fibers in the host tissues and display partial functional improvement in these diseases. Therefore, the development of efficient purification methods of quiescent satellite cells from skeletal muscle, as well as the establishment of satellite cell-derived myoblast cultures and transplantation methods for myoblasts, are essential for understanding the molecular mechanisms behind satellite cell self-renewal, activation, and differentiation. Additionally, the development of cell-based therapies for muscular dystrophy and other regenerative diseases are also dependent upon these factors.

However, current prospective purification methods of quiescent satellite cells require the use of expensive fluorescence-activated cell sorting (FACS) machines. Here, we present a new method for the rapid, economical, and reliable purification of quiescent satellite cells from adult mouse skeletal muscle by enzymatic dissociation followed by magnetic-activated cell sorting (MACS). Following isolation of pure quiescent satellite cells, these cells can be cultured to obtain large numbers of myoblasts after several passages. These freshly isolated quiescent satellite cells or ex vivo expanded myoblasts can be transplanted into cardiotoxin (CTX)-induced regenerating mouse skeletal muscle to examine the contribution of donor-derived cells to regenerating muscle fibers, as well as to satellite cell compartments for the examination of self-renewal activities.

Freshly isolated quiescent satellite cells display a small, round shape (Figure&#160;1G), and express Pax7 as a definitive marker for quiescent satellite cells. More than 90% of freshly isolated cells express Pax7 (Figure&#160;1H and&#160;1I). Most contaminated cells are from blood cells which do not efficiently grow in vitro following myoblast culture conditions. Thus, satellite cell-derived myoblasts dominate in the culture. Optionally, we can repeat the steps...

Watch this Scientific Journal Video about Isolation, Culture, and Transplantation of Muscle Satellite Cells at JoVE.com

Isolation, Culture, and Transplantation of Muscle Satellite Cells

The isolation and culture of a pure population of quiescent satellite cells, a muscle stem cell population, is essential to the understanding of muscle stem cell biology and regeneration, as well as stem cell transplantation for therapies in muscular dystrophy and other degenerative diseases.&#160;

Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal ...

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Unit 1

Fibroblast Transformation and Muscle Stem Cells

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41.2K Views.  University of Minnesota Medical School.  العزلة وثقافة السكان نقية من الخلايا الأقمار الصناعية هادئة، والسكان الخلايا الجذعية العضلية، أمر ضروري لفهم العضلات الجذعية بيولوجيا الخلايا وتجديدها، فضلا عن زرع الخلايا الجذعية لعلاج ضمور العضلات في والأمراض التنكسية الأخرى. 

Video: Isolation, Culture, and Transplantation of Muscle Satellite Cells

Isolation and Transplantation of Hematopoietic Stem Cells (HSCs)

Isolation and Transplantation of Hematopoietic Stem Cells HSCs

Isolation of Human Umbilical Arterial Smooth Muscle Cells (HUASMC)

The human umbilical cord (UC) is a biological sample that can be easily obtained just after birth. This biological sample is, most of the time, discarded and their collection does not imply any added risk to the newborn or mother s health. Moreover no ethical concerns are raised. The UC is composed by one vein and two arteries from which both endothelial cells (ECs) 1 and smooth muscle cells (SMCs) 2, two of the main cellular components of blood vessels, can be isolated. In this project the SMCs were obtained after enzymatic treatment of the UC arteries accordingly the experimental procedure previously described by Jaffe et al 3. After cell isolation they were kept in t-flash with DMEM-F12 supplemented with 5% of fetal bovine serum and were cultured for several passages. Cells maintained their morphological and other phenotypic characteristics in the different generations. The aim of this study was to isolate smooth muscle cells in order to use them as models for future assays with constrictor drugs, isolate and structurally characterize L-type calcium channels, to study cellular and molecular aspects of the vascular function 4 and to use them in tissue engineering.

Isolation of Human Umbilical Arterial Smooth Muscle Cells HUASMC

The umbilical cords are used to isolate smooth muscle cells by different ways. In this work we used the enzymatic treatment to isolated smooth muscle cells.

The human umbilical cord (UC) is a biological sample that can be easily obtained just after birth. This biological sample is, most of the time, discarded ...

Adult and Embryonic Skeletal Muscle Microexplant Culture and Isolation of Skeletal Muscle Stem Cells

Cultured embryonic and adult skeletal muscle cells have a number of different uses. The micro-dissected explants technique described in this chapter is a robust and reliable method for isolating relatively large numbers of proliferative skeletal muscle cells from juvenile, adult or embryonic muscles as a source of skeletal muscle stem cells. The authors have used micro-dissected explant cultures to analyse the growth characteristics of skeletal muscle cells in wild-type and dystrophic muscles. Each of the components of tissue growth, namely cell survival, proliferation, senescence and differentiation can be analysed separately using the methods described here. The net effect of all components of growth can be established by means of measuring explant outgrowth rates. The micro-explant method can be used to establish primary cultures from a wide range of different muscle types and ages and, as described here, has been adapted by the authors to enable the isolation of embryonic skeletal muscle precursors.
Uniquely, micro-explant cultures have been used to derive clonal (single cell origin) skeletal muscle stem cell (SMSc) lines which can be expanded and used for in vivo transplantation. In vivo transplanted SMSc behave as functional, tissue-specific, satellite cells which contribute to skeletal muscle fibre regeneration but which are also retained (in the satellite cell niche) as a small pool of undifferentiated stem cells which can be re-isolated into culture using the micro-explant method.

The micro-dissected explants technique is a robust and reliable method for isolating proliferative skeletal muscle cells from juvenile, adult or embryonic muscles as a source of skeletal muscle stem cells. Uniquely, these cells have been clonally derived to produce skeletal muscle stem cell lines used for in vivo transplantation.

Cultured embryonic and adult skeletal muscle cells have a number of different uses. The micro-dissected explants technique described in this chapter is a ...

Isolation and Culture of Avian Embryonic Valvular Progenitor Cells

Proper formation and function of embryonic heart valves is critical for developmental progression. The early embryonic heart is a U-shaped tube of endocardium surrounded by myocardium. The myocardium secretes cardiac jelly, a hyaluronan-rich gelatinous matrix, into the atrioventricular (AV) junction and outflow tract (OFT) lumen. At stage HH14 valvulogenesis begins when a subset of endocardial cells receive signals from the myocardium, undergo endocardial to mesenchymal transformation (EMT), and invade the cardiac jelly. At stage HH25 the valvular cushions are fully mesenchymalized, and it is this mesenchyme that eventually forms the valvular and septal apparatus of the heart. Understanding the mechanisms that initiate and modulate the process of EMT and cell differentiation are important because of their connection to serious congenital heart defects. In this study we present methods to isolate pre-EMT endocardial and post-EMT mesenchymal cells, which are the two different cell phenotypes of the prevalvular cushion. Pre-EMT endocardial cells can be cultured with or without the myocardium. Post-EMT AV cushion mesenchymal cells can be cultured inside mechanically constrained or stress-free collagen gels. These 3D in vitro models mimic key valvular morphogenic events and are useful for deconstructing the mechanisms of early and late stage valvulogenesis.

This article will provide a method for isolating and culturing quail or chicken HH14- valve endocardial cells and HH25 valve cushion mesenchymal cells.

Proper formation and function of embryonic heart valves is critical for developmental progression. The early embryonic heart is a U-shaped tube of ...

Isolation and Culture of Pulmonary Endothelial Cells from Neonatal Mice

Endothelial cells provide a useful research model in many areas of vascular biology. Since its first isolation 1, human umbilical vein endothelial cells (HUVECs) have shown to be convenient, easy to obtain and culture, and thus are the most widely studied endothelial cells. However, for research focused on processes like angiogenesis, permeability or many others, microvascular endothelial cells (ECs) are a much more physiologically relevant model to study 2. Furthermore, ECs isolated from knockout mice provide a useful tool for analysis of protein function ex vivo. Several approaches to isolate and culture microvascular ECs of different origin have been reported to date 3-7, but consistent isolation and culture of pure ECs is still a major technical problem in many laboratories. Here, we provide a step-by-step protocol on a reliable and relatively simple method of isolating and culturing mouse lung endothelial cells (MLECs). In this approach, lung tissue obtained from 6- to 8-day old pups is first cut into pieces, digested with collagenase/dispase (C/D) solution and dispersed mechanically into single-cell suspension. MLECS are purified from cell suspension using positive selection with anti-PECAM-1 antibody conjugated to Dynabeads using a Magnetic Particle Concentrator (MPC). Such purified cells are cultured on gelatin-coated tissue culture (TC) dishes until they become confluent. At that point, cells are further purified using Dynabeads coupled to anti-ICAM-2 antibody. MLECs obtained with this protocol exhibit a cobblestone phenotype, as visualized by phase-contrast light microscopy, and their endothelial phenotype has been confirmed using FACS analysis with anti-VE-cadherin 8 and anti-VEGFR2 9 antibodies and immunofluorescent staining of VE-cadherin. In our hands, this two-step isolation procedure consistently and reliably yields a pure population of MLECs, which can be further cultured. This method will enable researchers to take advantage of the growing number of knockout and transgenic mice to directly correlate in vivo studies with results of in vitro experiments performed on isolated MLECs and thus help to reveal molecular mechanisms of vascular phenotypes observed in vivo.

Here, we describe a protocol for isolation and culture of murine pulmonary endothelial cells. This method comprises mechanic and enzymatic lung tissue dissociation as well as a 2-step purification process using anti-PECAM-1 and anti-ICAM-2 antibodies conjugated to magnetic beads, which produces a pure endothelial cell population of mostly microvascular origin.

Endothelial cells provide a useful research model in many areas of vascular biology. Since its first isolation 1, human umbilical vein endothelial cells ...

Isolation and Primary Culture of Rat Hepatic Cells

Primary hepatocyte culture is a valuable tool that has been extensively used in basic research of liver function, disease, pathophysiology, pharmacology and other related subjects. The method based on two-step collagenase perfusion for isolation of intact hepatocytes was first introduced by Berry and Friend in 1969 1 and, since then, has undergone many modifications. The most commonly used technique was described by Seglenin 1976 2. Essentially, hepatocytes are dissociated from anesthetized adult rats by a non-recirculating collagenase perfusion through the portal vein. The isolated cells are then filtered through a 100 &mu;m pore size mesh nylon filter, and cultured onto plates. After 4-hour culture, the medium is replaced with serum-containing or serum-free medium, e.g. HepatoZYME-SFM, for additional time to culture. These procedures require surgical and sterile culture steps that can be better demonstrated by video than by text. Here, we document the detailed steps for these procedures by both video and written protocol, which allow consistently in the generation of viable hepatocytes in large numbers.

Primary hepatocytes provide a valuable tool to evaluate biochemical, molecular, and metabolic functions in a physiologically relevant experimental system. We describe a reliable protocol for rat in situ liver perfusion, which consistently generates viable hepatocytes up to 1.0 &times; 108 cells per preparation with cell viability between 88 ~ 96%.

Primary hepatocyte culture is a valuable tool that has been extensively used in basic research of liver function, disease, pathophysiology, pharmacology ...

Isolation and Culture of Individual Myofibers and their Satellite Cells from Adult Skeletal Muscle

Muscle regeneration in the adult is performed by resident stem cells called satellite cells. Satellite cells are defined by their position between the basal lamina and the sarcolemma of each myofiber. Current knowledge of their behavior heavily relies on the use of the single myofiber isolation protocol. In 1985, Bischoff described a protocol to isolate single live fibers from the Flexor Digitorum Brevis (FDB) of adult rats with the goal to create an in vitro system in which the physical association between the myofiber and its stem cells is preserved 1. In 1995, Rosenblattmodified the Bischoff protocol such that myofibers are singly picked and handled separately after collagenase digestion instead of being isolated by gravity sedimentation 2, 3. The Rosenblatt or Bischoff protocol has since been adapted to different muscles, age or conditions 3-6. The single myofiber isolation technique is an indispensable tool due its unique advantages. First, in the single myofiber protocol, satellite cells are maintained beneath the basal lamina. This is a unique feature of the protocol as other techniques such as Fluorescence Activated Cell Sorting require chemical and mechanical tissue dissociation 7. Although the myofiber culture system cannot substitute for in vivo studies, it does offer an excellent platform to address relevant biological properties of muscle stem cells. Single myofibers can be cultured in standard plating conditions or in floating conditions. Satellite cells on floating myofibers are subjected to virtually no other influence than the myofiber environment. Substrate stiffness and coating have been shown to influence satellite cells' ability to regenerate muscles 8, 9 so being able to control each of these factors independently allows discrimination between niche-dependent and -independent responses. Different concentrations of serum have also been shown to have an effect on the transition from quiescence to activation. To preserve the quiescence state of its associated satellite cells, fibers should be kept in low serum medium 1-3. This is particularly useful when studying genes involved in the quiescence state. In serum rich medium, satellite cells quickly activate, proliferate, migrate and differentiate, thus mimicking the in vivo regenerative process 1-3. The system can be used to perform a variety of assays such as the testing of chemical inhibitors; ectopic expression of genes by virus delivery; oligonucleotide based gene knock-down or live imaging. This video article describes the protocol currently used in our laboratory to isolate single myofibers from the Extensor Digitorum Longus (EDL) muscle of adult mice (6-8 weeks old).

Isolation and culture of myofibers is the gold standard in vitro system to study the transition of satellite cells through quiescence, activation and differentiation. Importantly, the single myofiber culture system preserves the myofiber/stem cell association, which is an essential component of the muscle stem cell niche.

Muscle  regeneration in the adult is performed by resident stem cells called satellite  cells. Satellite cells are defined by  their position between the ...

Isolation and Culture of Mouse Primary Pancreatic Acinar Cells

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one week. More than 20 x 106 acinar cells can be obtained from a single murine pancreas. This protocol offers the possibility to independently process as many as 10 pancreases in parallel. Because it preserves acinar architecture, this model is well suited for studying the physiology of the exocrine pancreas in vitro in contrast to cell lines established from pancreatic tumors, which display many genetic alterations resulting in partial or total loss of their acinar differentiation.

In this publication, we describe a rapid and convenient procedure for isolating and culturing primary pancreatic acinar cells from the murine pancreas. This method constitutes a valuable approach to study the physiology of fresh primary normal/untransformed exocrine pancreatic cells.

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one ...

Isolation of Pulmonary Artery Smooth Muscle Cells from Neonatal Mice

Pulmonary hypertension is a significant cause of morbidity and mortality in infants. Historically, there has been significant study of the signaling pathways involved in vascular smooth muscle contraction in PASMC from fetal sheep. While sheep make an excellent model of term pulmonary hypertension, they are very expensive and lack the advantage of genetic manipulation found in mice. Conversely, the inability to isolate PASMC from mice was a significant limitation of that system. Here we described the isolation of primary cultures of mouse PASMC from P7, P14, and P21 mice using a variation of the previously described technique of Marshall et al.26 that was previously used to isolate rat PASMC. These murine PASMC represent a novel tool for the study of signaling pathways in the neonatal period. Briefly, a slurry of 0.5% (w/v) agarose + 0.5% iron particles in M199 media is infused into the pulmonary vascular bed via the right ventricle (RV). The iron particles are 0.2 &#956;M in diameter and cannot pass through the pulmonary capillary bed. Thus, the iron lodges in the small pulmonary arteries (PA). The lungs are inflated with agarose, removed and dissociated. The iron-containing vessels are pulled down with a magnet. After collagenase (80 U/ml) treatment and further dissociation, the vessels are put into a tissue culture dish in M199 media containing 20% fetal bovine serum (FBS), and antibiotics (M199 complete media) to allow cell migration onto the culture dish. This initial plate of cells is a 50-50 mixture of fibroblasts and PASMC. Thus, the pull down procedure is repeated multiple times to achieve a more pure PASMC population and remove any residual iron. Smooth muscle cell identity is confirmed by immunostaining for smooth muscle myosin and desmin.

We have developed a novel and reproducible technique to isolate primary cultures of pulmonary artery smooth muscle cells (PASMC) from mice as young as P7, thereby allowing better study of the signaling pathways involved in neonatal smooth muscle cell contraction and relaxation.

Pulmonary hypertension is a significant cause of morbidity and mortality in infants. Historically, there has been significant study of the signaling ...

Isolation and Primary Culture of Mouse Aortic Endothelial Cells

The vascular endothelium is essential to normal vascular homeostasis. Its dysfunction participates in various cardiovascular disorders. The mouse is an important model for cardiovascular disease research. This study demonstrates a simple method to isolate and culture endothelial cells from the mouse aorta without any special equipment. To isolate endothelial cells, the thoracic aorta is quickly removed from the mouse body, and the attached adipose tissue and connective tissue are removed from the aorta. The aorta is cut into 1 mm rings. Each aortic ring is opened and seeded onto a growth factor reduced matrix with the endothelium facing down. The segments are cultured in endothelial cell growth medium for about 4 days. The endothelial sprouting starts as early as day 2. The segments are then removed and the cells are cultured continually until they reach confluence. The endothelial cells are harvested using neutral proteinase and cultured in endothelial cell growth medium for another two passages before being used for experiments. Immunofluorescence staining indicated that after the second passage the majority of cells were double positive for Dil-ac-LDL uptake, Lectin binding, and CD31 staining, the typical characteristics of endothelial cells. It is suggested that cells at the second to third passages are suitable for in vitro and in vivo experiments to study the endothelial biology. Our protocol provides an effective means of identifying specific cellular and molecular mechanisms in endothelial cell physiopathology.

The vascular endothelial cells play a significant role in many important cardiovascular disorders. This article describes a simple method to isolate and expand endothelial cells from the mouse aorta without using any special equipment. Our protocol provides an effective means of identifying mechanisms in endothelial cell physiopathology.

The vascular endothelium is essential to normal vascular homeostasis. Its dysfunction participates in various cardiovascular disorders. The mouse is an ...