Name: isolation, culture, characterization, and differentiation of human muscle progenitor cells from the skeletal muscle biopsy procedure
Uploaded: 2019-08-23T13:30:00.000+00:00
Duration: 8 s
Description: Watch this Scientific Journal Video about Isolation, Culture, Characterization, and Differentiation of Human Muscle Progenitor Cells from the Skeletal Muscle Biopsy Procedure at JoVE.com

The authors thank the Cornell University, Biotechnology Resource Center Imaging Facility for their help with fluorescence activated cell sorting. We also thank Molly Gheller for her help with participant recruitment and Erica Bender for conducting the skeletal muscle biopsies. Finally, we thank the participants for their time and participation in the study.This work was supported by the National Institute on Aging of the National Institutes of Health under Award Number R01AG058630 (to B.D.C. and A.E.T.), by a Glenn Foundation for Medical Research and American Federation for Aging Research Grant for Junior Faculty (to B.D.C.), and by the President&#39;s Council for Cornell Women (to A.E.T.).

<ol>
	<li>Janssen, I., Heymsfield, S. B., Wang, Z., Ross, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skeletal+muscle+mass+and+distribution+in+468+men+and+women+aged+18-88+yr.">Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr.</a> Journal of Applied Physiology. 89 (1), 81-88 (2000).</li><li>D'Souza, D. 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=Decreased+satellite+cell+number+and+function+in+humans+and+mice+with+type+1+diabetes+is+the+result+of+altered+notch+signaling.">Decreased satellite cell number and function in humans and mice with type 1 diabetes is the result of altered notch signaling.</a> Diabetes. 65 (10), 3053-3061 (2016).</li><li>Scheele, 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=Satellite+cells+derived+from+Obese+humans+with+type+2+diabetes+and+differentiated+into+Myocytes+in+vitro+exhibit+abnormal+response+to+IL-6.">Satellite cells derived from Obese humans with type 2 diabetes and differentiated into Myocytes in vitro exhibit abnormal response to IL-6.</a> PLoS One. 7 (6), e39657 (2012).</li><li>Riddle, E. S., Bender, E. L., Thalacker-Mercer, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expansion+capacity+of+human+muscle+progenitor+cells+differs+by+age,+sex,+and+metabolic+fuel+preference.">Expansion capacity of human muscle progenitor cells differs by age, sex, and metabolic fuel preference.</a> American Journal of Physiology: Cell Physiology. 315 (5), C643-C652 (2018).</li><li>Charville, G. 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=Ex+vivo+expansion+and+in+vivo+self-renewal+of+human+muscle+stem+cells.">Ex vivo expansion and in vivo self-renewal of human muscle stem cells.</a> Stem Cell Reports. 5 (4), 621-632 (2015).</li><li>Alexander, M. 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=CD82+Is+a+Marker+for+Prospective+Isolation+of+Human+Muscle+Satellite+Cells+and+Is+Linked+to+Muscular+Dystrophies.">CD82 Is a Marker for Prospective Isolation of Human Muscle Satellite Cells and Is Linked to Muscular Dystrophies.</a> Cell Stem Cell. 19 (6), 800-807 (2016).</li><li>Thalacker-Mercer, 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=Cluster+analysis+reveals+differential+transcript+profiles+associated+with+resistance+training-induced+human+skeletal+muscle+hypertrophy.">Cluster analysis reveals differential transcript profiles associated with resistance training-induced human skeletal muscle hypertrophy.</a> Physiological Genomics. 45 (12), 499-507 (2013).</li><li>Garcia, S. 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=High-Yield+Purification,+Preservation,+and+Serial+Transplantation+of+Human+Satellite+Cells.">High-Yield Purification, Preservation, and Serial Transplantation of Human Satellite Cells.</a> Stem Cell Reports. 10 (3), 1160-1174 (2018).</li><li>Yokoyama, W. M., Thompson, M. L., Ehrhardt, R. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cryopreservation+and+thawing+of+cells.">Cryopreservation and thawing of cells.</a> Current Protocols in Immunology. , (2012).</li><li>Bareja, A., Billin, A. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Satellite+cell+therapy+-+from+mice+to+men.">Satellite cell therapy - from mice to men.</a> Skeletal Muscle. 3 (1), 2 (2013).</li><li>Riddle, E. S., Bender, E. L., Thalacker-Mercer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcript+profile+distinguishes+variability+in+human+myogenic+progenitor+cell+expansion+capacity.">Transcript profile distinguishes variability in human myogenic progenitor cell expansion capacity.</a> Physiological Genomics. 50 (10), 817-827 (2018).</li><li>Xu, X., 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=Human+Satellite+Cell+Transplantation+and+Regeneration+from+Diverse+Skeletal+Muscles.">Human Satellite Cell Transplantation and Regeneration from Diverse Skeletal Muscles.</a> Stem Cell Reports. 5 (3), 419-434 (2015).</li></ol>

The authors have nothing to disclose.

Primary hMPCs are an important research model used to understand skeletal muscle biology and the regenerative process. Additionally, hMPCs have the potential to be used for therapy. However, there are recognized challenges in using primary hMPCs for both research and therapy, including the limited understanding of cells derived from humans10. There is also a large degree of variation in the expansion capacity among donor cultures, which limits the potential for use of hMPCs and can affect research...

Skeletal muscle is the largest organ system in the human body, accounting for 30&#8722;40% of whole body mass1. In addition to its well-recognized role in locomotion, skeletal muscle maintains body temperature and posture, and plays a central role in whole body nutrient homeostasis. Research involving human participants, animals, and cell culture models are all valuable to address questions pertaining to skeletal muscle biology and regeneration. Isolation and culture of human primary muscle progenitor cells (hMPCs) provides a robust model that allows for cell culture techniques and manipulations to be applied to human samples. An advantage of using hMPCs is that they retain the genetic and metabolic phenotype from each donor2,3. Maintenance of the donor phenotype allows researchers to examine inter-individual variation in the myogenic process. For example, we have employed our hMPC characterization method to identify age- and sex-related differences in hMPC population expansion capacity4.
The purpose of this protocol is to detail techniques to isolate, culture, characterize, and differentiate&#160;hMPCs from skeletal muscle biopsy tissue. Building on previous work that described hMPCs and identified potential cell surface makers for hMPC isolation5,6, this protocol fills a critical gap in knowledge by linking the isolation to the characterization of hMPCs. Further, the detailed step-by-step instructions included in this protocol make hMPC isolation and characterization accessible to a broad scientific audience, including those with limited prior experience with hMPCs. Our protocol is among the first to describe use of an imaging cytometer to track cell populations. Newly designed imaging cytometers are state-of-the-art, high-throughput, and microplate-based, enabling live cell imaging, cell counting, and multichannel fluorescence analysis of all cells in each well of a culture vessel within minutes. This system allows for rapid quantification of dynamic changes in proliferation and viability of an entire cell population with only minimal disruption to the culture. For example, we are able to perform objective measures of confluence on successive days in vitro to determine growth kinetics of each culture derived from different donors. Many protocols in the literature, particularly those involving the differentiation of MPCs, require cells to reach a defined level of confluence before initiating differentiation or treatment7. Our method allows for objective determination of the confluence of each well in a culture vessel allowing researchers to initiate treatment in an unbiased, non-subjective manner.
In the past, a major limitation of using primary hMPCs was low yields that limit the number of cells available for experiments. We and others have shown the yield of MPCs from skeletal muscle biopsy tissue is 1&#8722;15 MPCs per milligram of tissue (Figure 1)8. Because our protocol allows for four passages of the cells prior to purification with fluorescence activated cell sorting (FACS), our cryopreserved hMPC yields, derived from small amounts of biopsy tissue (50&#8722;100 mg), are sufficient to address research aims where multiple experiments are required. Our FACS protocol produces a ~80% pure (Pax7 positive) MPC population, thus our protocol is optimized for both yield and purity.

<table><tbody><tr><td>0.25% Trypsin, 2.21 mM EDTA</td><td>Corning</td><td>25-053-Cl</td><td>Trypsin used for removing adherent &lt;em&gt;h&lt;/em&gt;MPCs from cell culture vessels</td></tr><tr><td>10 cm cell culture plate</td><td>VWR</td><td>664160</td><td>Plates used for culturing &lt;em&gt;h&lt;/em&gt;MPCs</td></tr><tr><td>15 mL Falcon tube</td><td>Falcon</td><td>352196</td><td>15 mL conical tubes used throughout the &lt;em&gt;h&lt;/em&gt;MPC isolation and culturing protocols</td></tr><tr><td>24 well cell culture plate</td><td>Grenier Bio-One</td><td>662 160</td><td>Plates used for culturing &lt;em&gt;h&lt;/em&gt;MPCs</td></tr><tr><td>7-AAD Viability Staining Solution</td><td>eBioscience</td><td>00-6993-50</td><td>Viability stain for identifying living cells during FACS sorting</td></tr><tr><td>Alexa Fluor 488 anti-human CD29, Clone: TS2/16</td><td>BioLegend</td><td>303016</td><td>Conjugated antibody for FACS&amp;nbsp;</td></tr><tr><td>Black 96-well cell culture plate</td><td>Grenier Bio-One</td><td>655079</td><td>96-well cell culture plate ideal for fluorescent imaging using the Celigo S</td></tr><tr><td>Celigo S</td><td>Nexcelcom Bioscience</td><td></td><td>Imaging cytometer used to track &lt;em&gt;h&lt;/em&gt;MPC cultures</td></tr><tr><td>Cell Strainer</td><td>VWR</td><td>352350</td><td>Cell strainer to eliminate large pieces of debris during muscle biopsy processing</td></tr><tr><td>Collagen Type I (Rat Tail)</td><td>Corning</td><td>354236</td><td>Collagen for coating cell culture plates&amp;nbsp;</td></tr><tr><td>Collagenase D</td><td>Roche</td><td>11 088 882 001</td><td>Used for degradation of collagen and other connective tissue in the skeletal muscle biopsy tissue</td></tr><tr><td>Dimethyl Sulfoxide</td><td>VWR</td><td>WN182</td><td>Used for cryopreservation of &lt;em&gt;h&lt;/em&gt;MPCs</td></tr><tr><td>Dispase II</td><td>Sigma Life Sciences</td><td>D4693</td><td>A protease used for enzymatic digestion of skeletal muscle biopsy tissue</td></tr><tr><td>Dulbecco&#039;s Modified Eagle Medium Low Glucose powder</td><td>Gibco</td><td>31600-034</td><td>Low glucose DMEM for muscle biopsy processing</td></tr><tr><td>Dulbecco&#039;s Phosphate Buffered Saline</td><td>Gibco</td><td>21600-010</td><td>PBS for muscle biopsy processing</td></tr><tr><td>EDTA Disodium Salt Dihydrate</td><td>J.T. Baker</td><td>4040-01&amp;nbsp;</td><td>Required for FACS buffer</td></tr><tr><td>Fetal Bovine Serum</td><td>VWR</td><td>89510-186&amp;nbsp;</td><td>Fetal bovine serum used for &lt;em&gt;h&lt;/em&gt;MPC growth media</td></tr><tr><td>Ham&#039;s F12</td><td>Gibco</td><td>21700-026</td><td>Base media for &lt;em&gt;h&lt;/em&gt;MPCs</td></tr><tr><td>Heat Inactivated Equine Serum</td><td>Gibco</td><td>26-050-070</td><td>Horse serum used to make &lt;em&gt;h&lt;/em&gt;MPC differentiation media</td></tr><tr><td>Hemocytometer</td><td>iNCyto</td><td>DHC-N0105</td><td>Used to count cells</td></tr><tr><td>Hibernate A</td><td>Gibco</td><td>A1247501</td><td>Media for preserving skeletal muscle biopsy tissue</td></tr><tr><td>Hoechst 33342, trihydrochloride, trihydrate</td><td>Life Technologies</td><td>H21492</td><td>DNA stain for identifying all cells using the Celigo S</td></tr><tr><td>Isopropanol</td><td>Fisher Scientific</td><td>A416P-4</td><td>Used for controlled rate freezing of &lt;em&gt;h&lt;/em&gt;MPCs</td></tr><tr><td>Moxi buffer</td><td>Orflo</td><td>MXA006</td><td>Buffer for automated cell counter</td></tr><tr><td>Moxi Cassettes</td><td>Orflo</td><td>MXC002</td><td>Cassesttes for automated cell counter</td></tr><tr><td>Moxi z Mini Automated Cell Counter</td><td>Orflo</td><td></td><td>Automated cell counter</td></tr><tr><td>Mr. Frosty Freezing Container</td><td>Thermo Fisher Scientific</td><td>5100-0001</td><td>Commerically available controlled rate cell freezing container</td></tr><tr><td>Normal Goat Serum (10%)</td><td>Thermo Fisher Scientific</td><td>50062Z</td><td>Goat serum used in FACS buffer</td></tr><tr><td>PE-Cy7 Mouse Anti-human CD56 , Clone: B159</td><td>BD Pharmingen</td><td>557747</td><td>Conjugated antibody for FACS&amp;nbsp;</td></tr><tr><td>Penicillin/Streptomycin 100x Solution</td><td>Corning</td><td>30-002-CI</td><td>Antibiotics added to culture media</td></tr><tr><td>Propidium iodide</td><td>Thermo Fisher Scientific</td><td>P3566</td><td>DNA stain for identifying dead cells using the Celigo S</td></tr><tr><td>Recombinant Human basic fibroblast growth factor</td><td>Promega</td><td>G5071</td><td>Supplement in &lt;em&gt;h&lt;/em&gt;MPC growth media to prevent spontaneous differentiation</td></tr><tr><td>Recovery Cell Culture Freezing Medium&amp;nbsp;</td><td>Gibco</td><td>12648-010</td><td>Media used to cryoperseve muscle biopsy slurries</td></tr><tr><td>Sodium Bicarbonate</td><td>Fisher Scientific</td><td>S233-3</td><td>Added to Ham&#039;s F12</td></tr><tr><td>Sterile Round Bottom 5 mL tubes</td><td>VWR</td><td>60818-565</td><td>Tubes used for FACS</td></tr><tr><td>UltraComp eBeads</td><td>eBioscience</td><td>01-2222-42</td><td>Compensation beads fort calibrating flow FACS settings</td></tr></tbody></table>

isolation, culture, characterization, and differentiation of human muscle progenitor cells from the skeletal muscle biopsy procedure

The use of primary human tissue and cells is ideal for the investigation of biological and physiological processes such as the skeletal muscle regenerative process. There are recognized challenges to working with human primary adult stem cells, particularly human muscle progenitor cells (hMPCs) derived from skeletal muscle biopsies, including low cell yield from collected tissue and a large degree of donor heterogeneity of growth and death parameters among cultures. While incorporating heterogeneity into experimental design requires a larger sample size to detect significant effects, it also allows us to identify mechanisms that underlie variability in hMPC&#160;expansion capacity, and thus allows us to better understand heterogeneity in skeletal muscle regeneration. Novel mechanisms that distinguish the expansion capacity of cultures have the potential to lead to the development of therapies to improve skeletal muscle regeneration.

Representative flow cytometry results of hMPC isolation from human muscle tissue can be viewed in Figure 1. hMPCs can be identified by first gating events based on side scatter and forward scatter to eliminate dead cells or debris, followed by selecting only cells which are negative for 7-AAD and therefore are viable. Selection of cells positive for both the cell surface markers CD56 and CD29 represents the hMPC population. A biopsy of 60 mg only provides app...

Watch this Scientific Journal Video about Isolation, Culture, Characterization, and Differentiation of Human Muscle Progenitor Cells from the Skeletal Muscle Biopsy Procedure at JoVE.com

Isolation, Culture, Characterization, and Differentiation of Human Muscle Progenitor Cells from the Skeletal Muscle Biopsy Procedure

We present techniques for isolating, culturing, characterizing, and differentiating human primary muscle progenitor cells (hMPCs) obtained from skeletal muscle biopsy tissue. hMPCs obtained and characterized through these methods can be used to subsequently address research questions related to human myogenesis and skeletal muscle regeneration.

The use of primary human tissue and cells is ideal for the investigation of biological and physiological processes such as the skeletal muscle ...

isolation-culture-characterization-differentiation-human-muscle

Universidad de Cartagena UDEC

Research

JoVE Journal

Developmental Biology

8.2K Views.  Cornell University. We present techniques for isolating, culturing, characterizing, and differentiating human primary muscle progenitor cells (hMPCs) obtained from skeletal muscle biopsy tissue. hMPCs obtained and characterized through these methods can be used to subsequently address research questions related to human myogenesis and skeletal muscle regeneration.

Video: Isolation, Culture, Characterization, and Differentiation of Human Muscle Progenitor Cells from the Skeletal Muscle Biopsy Procedure

Isolation and Quantitative Immunocytochemical Characterization of Primary Myogenic Cells and Fibroblasts from Human Skeletal Muscle

The repair and regeneration of skeletal muscle requires the action of satellite cells, which are the resident muscle stem cells. These can be isolated from human muscle biopsy samples using enzymatic digestion and their myogenic properties studied in culture. Quantitatively, the two main adherent cell types obtained from enzymatic digestion are: (i) the satellite cells (termed myogenic cells or muscle precursor cells), identified initially as CD56+ and later as CD56+/desmin+ cells and (ii) muscle-derived fibroblasts, identified as CD56&#8211; and TE-7+. Fibroblasts proliferate very efficiently in culture and in mixed cell populations these cells may overrun myogenic cells to dominate the culture. The isolation and purification of different cell types from human muscle is thus an important methodological consideration when trying to investigate the innate behavior of either cell type in culture. Here we describe a system of sorting based on the gentle enzymatic digestion of cells using collagenase and dispase followed by magnetic activated cell sorting (MACS) which gives both a high purity (&#62;95% myogenic cells) and good yield (~2.8 x 106 &#177; 8.87 x 105 cells/g tissue after 7 days in vitro) for experiments in culture. This approach is based on incubating the mixed muscle-derived cell population with magnetic microbeads beads conjugated to an antibody against CD56 and then passing cells though a magnetic field. CD56+ cells bound to microbeads are retained by the field whereas CD56&#8211; cells pass unimpeded through the column. Cell suspensions from any stage of the sorting process can be plated and cultured. Following a given intervention, cell morphology, and the expression and localization of proteins including nuclear transcription factors can be quantified using immunofluorescent labeling with specific antibodies and an image processing and analysis package.

The main adherent cell types derived from human muscle are myogenic cells and fibroblasts. Here, cell populations are enriched using magnetic-activated cell sorting based on the CD56 antigen. Subsequent immunolabelling with specific antibodies and use of image analysis techniques allows quantification of cytoplasmic and nuclear characteristics in individual cells.

The repair and regeneration of skeletal muscle requires the action of satellite cells, which are the resident muscle stem cells. These can be isolated ...

Preparation and Culture of Myogenic Precursor Cells/Primary Myoblasts from Skeletal Muscle of Adult and Aged Humans

Skeletal muscle homeostasis depends on muscle growth (hypertrophy), atrophy and regeneration. During ageing and in several diseases, muscle wasting occurs. Loss of muscle mass and function is associated with muscle fiber type atrophy, fiber type switching, defective muscle regeneration associated with dysfunction of satellite cells, muscle stem cells, and other pathophysiological processes. These changes are associated with changes in intracellular as well as local and systemic niches. In addition to most commonly used rodent models of muscle ageing, there is a need to study muscle homeostasis and wasting using human models, which due to ethical implications, consist predominantly of in vitro cultures. Despite the wide use of human Myogenic Progenitor Cells (MPCs) and primary myoblasts in myogenesis, there is limited data on using human primary myoblast and myotube cultures to study molecular mechanisms regulating different aspects of age-associated muscle wasting, aiding in the validation of mechanisms of ageing proposed in rodent muscle. The use of human MPCs, primary myoblasts and myotubes isolated from adult and aged people, provides a physiologically relevant model of molecular mechanisms of processes associated with muscle growth, atrophy and regeneration. Here we describe in detail a robust, inexpensive, reproducible and efficient protocol for the isolation and maintenance of human MPCs&#160;and their progeny&#160;&#8212; myoblasts and myotubes from human muscle samples using enzymatic digestion. Furthermore, we have determined the passage number at which primary myoblasts from adult and aged people undergo senescence in an in vitro culture. Finally, we show the ability to transfect these myoblasts and the ability to characterize their proliferative and differentiation capacity and propose their suitability for performing functional studies of molecular mechanisms of myogenesis and muscle wasting in vitro.

This protocol describes a robust, reproducible and simple method of isolation and culture of myoblast progenitor cells from the skeletal muscle of adult and aged people. The muscles used here include foot and leg muscles. This approach enables the isolation of an enriched population of primary myoblasts for functional studies.

Skeletal muscle homeostasis depends on muscle growth (hypertrophy), atrophy and regeneration. During ageing and in several diseases, muscle wasting ...

Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement

Satellite cells (SC) are muscle stem cells located between the plasma membrane of muscle fibers and the surrounding basal lamina. They are essential for muscle regeneration. Upon injury, which occurs frequently in skeletal muscles, SCs are activated. They proliferate as myoblasts and differentiate to repair muscle lesions. Among many events that take place during muscle differentiation, cytosolic Ca2+ signals are of great importance. These Ca2+ signals arise from Ca2+ release from internal Ca2+ stores, as well as from Ca2+ entry from the extracellular space, particularly the store-operated Ca2+ entry (SOCE). This paper describes a methodology used to obtain a pure population of human myoblasts from muscle samples collected after orthopedic surgery. The tissue is mechanically and enzymatically digested, and the cells are amplified and then sorted by flow cytometry according to the presence of specific membrane markers. Once obtained, human myoblasts are expanded and committed to differentiate by removing growth factors from the culture medium. The expression levels of specific transcription factors and in vitro immunofluorescence are used to assess the myogenic differentiation process in control conditions and after silencing proteins involved in Ca2+ signaling. Finally, we detail the use of Fura-2 as a ratiometric Ca2+ probe that provides reliable and reproducible measurements of SOCE.

Here, we describe a methodology to obtain a pure population of human myoblasts from adult muscle tissue. These cells are used to study in vitro skeletal muscle differentiation and, in particular, to study proteins involved in Ca2+ signaling.

Satellite cells (SC) are muscle stem cells located between the plasma membrane of muscle fibers and the surrounding basal lamina. They are essential for ...

Isolation and Differentiation of Primary Myoblasts from Mouse Skeletal Muscle Explants

Primary myoblasts are undifferentiated proliferating precursors of skeletal muscle. They can be cultured and studied as muscle precursors or induced to differentiate into later stages of muscle development. The protocol provided here describes a robust method for the isolation and culture of a highly proliferative population of myoblast cells from young adult mouse skeletal muscle explants. These cells are useful for the study of the metabolic properties of skeletal muscle of different mouse models, as well as in other downstream applications such as transfection with exogenous DNA or transduction with viral expression vectors. The level of differentiation and metabolic profile of these cells depends on the length of exposure, and composition of the media used to induce myoblast differentiation. These methods provide a robust system for the study of mouse muscle cell metabolism ex vivo. Importantly, unlike in vivo models, the methods described here provide a cell population that can be expanded and studied with high levels of reproducibility.

Myoblasts are proliferating precursor cells that differentiate to form polynucleated myotubes and eventually skeletal muscle myofibers. Here, we present a protocol for efficient isolation and culture of primary myoblasts from young adult mouse skeletal muscles. The method enables molecular, genetic, and metabolic studies of muscle cells in culture.

Primary myoblasts are undifferentiated proliferating precursors of skeletal muscle. They can be cultured and studied as muscle precursors or induced to ...

Isolation and Immortalization of Patient-derived Cell Lines from Muscle Biopsy for Disease Modeling

The generation of patient-specific cell lines represents an invaluable tool for diagnostic or translational research, and these cells can be collected from skin or muscle biopsy tissue available during the patient&#8217;s diagnostic workup. In this protocol, we describe a technique for live cell isolation from small amounts of muscle or skin tissue for primary cell culture. Additionally, we provide a technique for the immortalization of myogenic cell lines and fibroblast cell lines from primary cells. Once cell lines are immortalized, substantial expansion of patient-derived cells can be achieved. Immortalized cells are amenable to many downstream applications, including drug screening and in vitro correction of the genetic mutation. Altogether, these protocols provide a reliable tool to generate and preserve patient-derived cells for downstream applications.

This protocol describes techniques for live cell isolation and primary culture of myogenic and fibroblast cell lines from muscle or skin tissue. A technique for the immortalization of these cell lines is also described. Altogether, these protocols provide a reliable tool to generate and preserve patient-derived cells for downstream applications.

The generation of patient-specific cell lines represents an invaluable tool for diagnostic or translational research, and these cells can be collected ...

Medicine

Isolating Stem Cells from Soft Musculoskeletal Tissues

Adult stem cells have long been discussed in regards to their application in regenerative medicine. Adult stem cells have generated a great deal of excitement for treating injured and diseased tissues due to their impressive capabilities to undergo multi-lineage cell differentiation and their self-renewal ability. Most importantly, these qualities have made them advantageous for use in autologous cell transplantation therapies. The current protocol will introduce the readers to the modified preplate technique where soft tissues of the musculoskeletal system, e.g. tendon and muscle, are 1st enzymatically dissociated and then placed in collagen coated flasks with medium. The supernatant, which is composed of medium and the remaining floating cells, is serially transferred daily to new flasks. The stem cells are the slowest to adhere to the flasks which is usually takes 5-7 days (serial transfers or preplates) . By using this technique, adult stem cells present in these tissues can be easily harvested through fairly non-invasive procedures.

Isolating adult stem cells from musculoskeletal soft tissues based on the cell's adherence speed to flask.

Adult stem cells have long been discussed in regards to their application in regenerative medicine. Adult stem cells have generated a great deal of ...

Biology

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 ...

Purification of Progenitors from Skeletal Muscle

Skeletal muscle contains multiple progenitor populations of distinct embryonic origins and developmental potential. Myogenic progenitors, usually residing in a "satellite cell position" between the myofiber plasma membrane and the laminin-rich basement membrane that ensheaths it, are self-renewing cells that are solely committed to the myogenic lineage1,2. We have recently described a second class of vessel associated progenitors that can generate myofibroblasts and white adipocytes, which responds to damage by efficiently entering proliferation and provides trophic support to myogenic cells during tissue regeneration3,4. One of the most trusted assays to determine the developmental and regenerative potential of a given cell population relies on their isolation and transplantation5-7. To this end we have optimized protocols for their purification by flow cytometry from enzymatically dissociated muscle, which we will outline in this article. The populations obtained using this method will contain either myogenic or fibro/adipogenic colony forming cells: no other cell types are capable of expanding in vitro or surviving in vivo delivery. However, when these populations are used immediately after the sort for molecular analysis (e.g qRT-PCR) one must keep in mind that the freshly sorted subsets may contain other contaminant cells that lack the ability of forming colonies or engrafting recipients.

Method for the enzymatic dissociation, surface labeling and purification by flow cytometry of fibro/adipogenic and myogenic progenitors from murine skeletal muscle.

Skeletal muscle contains multiple progenitor populations of distinct embryonic origins and developmental potential. Myogenic progenitors, usually residing ...

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 of Blood-vessel-derived Multipotent Precursors from Human Skeletal Muscle

Since the discovery of mesenchymal stem/stromal cells (MSCs), the native identity and localization&#160;of MSCs have been obscured by their retrospective isolation in culture. Recently, using fluorescence-activated cell sorting (FACS), we and other researchers prospectively identified and purified three subpopulations of multipotent precursor cells associated with the vasculature of human skeletal muscle. These three cell populations: myogenic endothelial cells (MECs), pericytes (PCs), and adventitial cells (ACs), are localized respectively to the three structural layers of blood vessels: intima, media, and adventitia. All of these human blood-vessel-derived stem cell (hBVSC) populations not only express classic MSC markers but also possess mesodermal developmental potentials similar to typical MSCs. Previously, MECs, PCs, and ACs have been isolated through distinct protocols and subsequently characterized in separate studies. The current isolation protocol, through modifications to the isolation process and adjustments in the selective cell surface markers, allows us to simultaneously purify all three hBVSC subpopulations by FACS from a single human muscle biopsy. This new method will not only streamline the isolation of multiple BVSC subpopulations but also facilitate future clinical applications of hBVSCs for distinct therapeutic purposes.

Blood vessels within human skeletal muscle harbor several multi-lineage precursor populations that are ideal for regenerative applications. This isolation method allows simultaneous purification of three multipotent precursor cell populations respectively from three structural layers of blood vessels: myogenic endothelial cells from intima, pericytes from media, and adventitial cells from adventitia.

Since the discovery of mesenchymal stem/stromal cells (MSCs), the native identity and localization&#160;of MSCs have been obscured by their retrospective ...