We are grateful to Prof. emeritus Jean-Claude Perriard and Evelyn Perriard (Swiss Federal Institute of Technology, Switzerland) for the introduction into isolation techniques for neonatal rat and mouse cardiomyocytes. We would like to thank Prof. Ju Chen and Prof. Sylvia Evans (UCSD, USA) for their support. Work in the laboratory of EE was funded by an MRC Career Establishment Grant. SL is supported by a K99/R00 pathway to independence award from the NIH/NHLBI (HL107744). TMM was supported by a postdoctoral fellowship from the American Heart Association (11POST7310066).

The following procedure describes a two-day protocol 16,17 for the isolation and culture of neonatal mouse cardiomyocytes. All solutions are sterile or sterile filtered. All tools are sterilized by surface sterilization with 75% ethanol. Except for the initial tissue extraction, all steps are performed in a sterile laminar flow cell culture hood. This protocol is intended for the isolation of neonatal mouse hearts from one-two litter(s) - approximately 5-14 pups, but may be adapted for larger litter sizes and rat neonatal cardiomyocytes. Scale media/enzyme usage as appropriate.
For work with neonatal rodents, refer to your local university guidelines and rules set forth by the legislature and/or animal care programs, and adhere to your institutionally approved animal protocol. All methods described in this protocol have been approved by the UC San Diego Institutional Animal Care and Use Committee (IACUC), and adhere to federal and state regulations.
Day 1.
1. Isolation of Cardiac Tissue from Neonatal Mice
<ol>
	<li>Prepare 50 ml of 1x PBS (without Ca2+, Mg2+) supplemented with 20 mM BDM 6-8, and disperse into two sterile bacterial dishes placed on ice.</li>
	<li>Prepare 10 ml of isolation medium in 50 ml sterile conical Falcon tube. Keep all solutions on ice. Sterilize scissors (one curved; one straight), and forceps (curved, Dumont No.7).</li>
	<li>1-3 days old neonatal mice are rinsed quickly in 75% ethanol solution for surface sterilization. Pups are decapitated using sterile scissors (straight), and the chest is opened along the sternum to allow access to the chest cavity and the heart (Figure 1A, Supplemental Movie S1). 
	Technical comment: Neonatal mice older than 3 days may be used, but result in fewer viable cells 2.</li>
	<li>Hearts are extracted from the body with curved scissors and transferred immediately into the bacterial dish containing 1x PBS (without Ca2+, Mg2+) with 20 mM BDM, on ice. All following steps are performed in the sterile cell-culture hood.</li>
	<li>Remove lung tissue, larger vessels (and atria, if desired). Wash hearts in the 1x PBS solution (without Ca2+, Mg2+) with 20 mM BDM (on ice) to remove blood. Transfer washed hearts from first dish into the second bacterial dish containing 1x PBS (without Ca2+, Mg2+) with 20 mM BDM (on ice) using forceps or a perforated spoon (Figure 1B).</li>
	<li>Transfer cleaned/washed hearts into a drop of isolation medium (approximately 250 &mu;l; Figure 1C) in a third bacterial dish (on ice) and use the curved scissors to mince hearts into small pieces (approximately 0.5-1 mm3, or smaller; Figure 1D, 1E).</li>
	<li>Transfer minced hearts into a conical tube containing 10 ml of the isolation medium (on ice), and incubate with gentle agitation at 4 &deg;C over night.</li>
</ol>
Day 2.
2. Enzymatic Tissue Digestion and Plating of Cells
<ol>
	<li>Weigh in 15 mg of collagenase/dispase mixture (Roche), and dissolve the enzyme mix in 10 ml L15-medium 5 supplemented with 20 mM BDM (digestion medium). Sterile filter the digestion medium in the cell culture hood into a new sterile 50 ml Falcon tube.</li>
	<li>Prepare 30 ml L-15 medium supplemented with 20 mM BDM, and plating medium.</li>
	<li>Coat cell-culture plates with collagen solution (Sigma C-8919) for a minimum of 1 hr. Remove collagen solution (can be reused) and dry collagen coated cell-culture dishes in sterile laminar flow cell-culture hood.</li>
	<li>Remove the conical tube containing the predigested hearts from 4 &deg;C. Tissue fragments should be aggregated (Figure 1G). Let the tissue fragments sink to the bottom of the tube and remove the supernatant (make sure not to loose any tissue fragments; normally, approx. 1 ml of the isolation medium may remain in the tube). Add 5 ml of digestion medium and 5 ml of L-15 supplemented with 20 mM BDM to tissue fragments and oxygenate suspension using oxygen or air for 1 min.</li>
	<li>Transfer the sealed conical tube containing the cardiac tissue fragments in digestion medium to 37 &deg;C water bath for about 2 min to adjust temperature of the digestion solution.</li>
	<li>Incubate cardiac tissue fragments at 37 &deg;C with gentle agitation for 20-30 min (e.g. shaker at 37 &deg;C, set to no more than 60rpm). Digestion times may greatly depend on enzyme mixture and lot number. Caution: longer incubation periods or higher enzyme concentrations may reduce cell viability. </li>
</ol>
Technical comment: We recommend usage of a collagenase/dispase mixture from Roche (Cat.No.: 10269638001) that has very little lot-to-lot variability. The classical enzyme for the isolation of mouse cardiomyocytes is trypsin and/or collagenase type II 3,16-20 available from Worthington (Cat No CLS-2). However, performance of collagenase II may differ substantially from lot-to-lot. Worthington typically allows for the testing of several collagenase lots to optimize digestion times and enzyme usage. Alternatively, Worthington sells a cardiomyocyte isolation kit with a pre-tested enzyme mixture included that can be adapted for the isolation of mouse cardiomyocytes 17 (Cat No.: NCIS).
<ol start="7">
	<li>Place sterile cell-strainer (40-100 &mu;m nylon mesh) in fresh sterile 50 ml conical falcon tube. Pre-wet cell strainer with 5 ml L-15 supplemented with 20 mM BDM. Gently triturate tissue fragments using a pre-wetted 10 ml cell-culture pipette for about 10-20 times. The tissue fragments should mostly disperse during this step, releasing the cells into suspension (Figure 1H).</li>
	<li>Let larger tissue fragments sediment and transfer supernatant containing suspended cells into fresh conical tube through cell-strainer (Figure 1I).</li>
	<li>Re-suspend the undigested tissue fragments in 5 ml digestion medium and incubate for an additional 5-10 min at 37 &deg;C with gentle agitation.</li>
	<li>After continuing digestion of remaining tissue fragments, gently triturate tissue for 10-20 times and add to conical tube containing cells from the first digest through cell strainer. Rinse cell-strainer with 5 ml L-15 supplemented with 20 mM BDM to allow passage of all digested cells.</li>
	<li>Centrifugate conical tube containing suspended cardiomyocytes for 5 min at 300 rpm (approx. 50-100 x g). Remove the supernatant (containing mostly fibroblasts and endothelial cells) and re-suspend cell pellet in 10 ml plating medium.</li>
	<li>Plate cells into 10 cm cell culture dish (Figure 2A) and incubate for 1-3 hr in cell culture incubator. This pre-plating step removes fibroblasts and endothelial cells (Figure 2B), which will adhere to the uncoated cell-culture dish (Figure 2C).</li>
	<li>After incubation, wash non-adherent cardiomyocytes from 10 cm culture dish (re-suspend cells by repeatedly pipetting the plating medium over the dish), and transfer resuspended cells to a sterile conical Falcon centrifuge tube (15 ml or 50 ml). 
	Optional: Repeat the pre-plating step to remove additional fibroblasts from cell-suspension. If desired, the adherent fibroblast and endothelial cells can be further cultured.</li>
	<li>Count cells (e.g. by using Neubauer hemocytometer, trypan blue exclusion staining 21).</li>
	<li>Plate cells into collagen coated cell culture dishes with a density of approximately 1.5 x 105 cells per cm2 (Figure 2D; see also comments in Table 1 on plating and coating). 
	Place dishes into cell culture incubator and leave undisturbed for 12-18 hr to allow for adherence and spreading of cardiomyocytes.</li>
</ol>
Day 3 - Culture of neonatal cardiomyocytes
<ol>
	<li>Prepare maintenance medium and prewarm in 37 &deg;C water bath. Refer to Table 1 for the addition of proliferation inhibitors or chronotropic agents, or the procedure for the liposomal transfection of neonatal mouse cardiomyocytes.</li>
	<li>One day after plating, cardiomyocytes should have adhered to the cell culture dish and optimally start spontaneously to contract (Figure 2E, 2F; Supplemental Movie S2; refer to Table 2 for common problems during the isolation/culture procedure). Replace plating medium with maintenance medium, and culture for additional 1-5 days. Change medium as necessary.</li>
</ol>

The use of animal models to study cardiac diseases has become standard in cardiovascular research. Closer biochemical characterization of these models (i.e. studying direct responses of cardiac cells to biochemical or biomechanical stimuli) typically requires the isolation of heart tissues or cardiomyocytes. Studies investigating physiological responses of the heart ex vivo (e.g. to acetylcholine 40, or in ischemia-reperfusion scenarios 41) generally utilize langendorff-pe...

The earliest reports for the successful dissociation and culture of rodent heart cells dates back to the 1960's 1,2. Even then, Harary and Farley noticed that cultured cardiomyocytes "may provide a unique system for the study of the requirements of the periodic contractility [, and may] provide a means of determining the contribution of various metabolic pathways for the [beating] process". Although Harary and Farley isolated and cultured cardiomyocytes from young rats, and the original protocol has been adapted and modified by many scientists over the years, the general isolation and culturing procedure has not greatly changed. However, better enzymes 3, standardized solutions 4,5, and the addition of the reversible channel and myosin ATPase inhibitor BDM to protect cells during the isolation procedure 6-9 has significantly improved cell-yield and viability.
Adult vs. neonatal cardiomyocytes
Cardiomyocytes isolated and cultured from neonatal mice or rats have several advantages over cultures of adult cardiomyocytes. Foremost, the isolation procedure for neonatal mouse or rat hearts is easier and less costly, when compared to the isolation of cardiomyocytes from adult mouse or rat 10. Neonatal cardiomyocytes are far less sensitive to reintroduction into a calcium-containing medium after dissociation, greatly increasing cell-yield. Another big advantage is that neonatal mouse cardiomyocytes undergo a more rapid dedifferentiation - redifferentiation cycle that typically results in spontaneously beating cells 20 hr after plating, while adult cardiomyocytes typically require pacing to induce contraction. Neonatal cardiomyocytes are also more readily transfectable with liposomal transfection methods, whereas adult cardiomyocytes require viral vectors for successful delivery of transgenic DNA. In contrast to neonatal cardiomyocytes, culture of adult rodent cardiomyocytes 11-13 allows for investigations of myofibrillar degradation and eventual reestablishment of the contractile apparatus. These characteristic morphological changes in adult cardiomyocytes occur over periods of 1-2 weeks. The dedifferentiation - redifferentiation cycle is accompanied by reexpression of the fetal gene program, thereby mimicking pathological changes observed in human cardiomyopathies 14. Another advantage of adult rat cardiomyocytes over the culture of neonatal cardiomyocytes is the ability to culture these cells for long periods of time.
Rat vs. mouse cardiomyocytes
The isolation and culture of rat neonatal cardiomyocytes has some benefits over that of mouse neonatal cardiomyocytes, including higher yields of viable cells and increased transfection rates. However, the wide usage of genetically modified mouse models for cardiac diseases (e.g. the muscle lim protein knockout mouse as model for dilated cardiomyopathy 15) has led to the adaptation of the isolation procedure for cardiomyocytes derived from neonatal mice. Although the protocols used to isolate neonatal rat and mouse cardiomyocytes are nearly identical, greater care must be taken in the selection of an appropriate enzyme mix for the latter. Indeed, neonatal mouse cardiomyocytes are generally more susceptible to overdigestion, resulting in a reduced cell-yield and viability. Moreover, the plating density should be adjusted, because cardiomyocytes derived from neonatal mice are somewhat smaller compared to cells derived from neonatal rat hearts.
With many uses for the investigation of morphological, electrophysiological, biochemical, cell-biological and biomechanical parameters as well as for the process of myofibrillogenesis, cultured neonatal cardiomyocytes have become one of the most versatile systems for the study of cardiac cell functions in vitro. The first step to a successful assay however, depends on an easy and reliable methodology to isolate neonatal mouse cardiomyocytes. Our protocol draws its methodology from many sources and was optimized for reproducibility and robustness. We discuss factors that influence cardiomyocyte-yield and viability, and provide a variety of options for the optimization of isolation and culture conditions.

<table border="1">
	<tbody>
		<tr>
			<td>Name of the reagent</td>
			<td>Company</td>
			<td>Catalogue number</td>
			<td>Comments (optional)</td>
		</tr>
		<tr>
			<td>BDM (2,3-Butanedione monoxime) 6-8</td>
			<td>Sigma</td>
			<td>B-0753</td>
			<td>prepare 0.2M stock solution in HBSS (without Ca2+, Mg2+), filter sterilize, can be kept at 4 &deg;C up to 6 months; Caution: Prolonged usage of BDM other than during isolation procedure may result in non-beating cells, decreased cell viability and/or significantly altered gene-expression during cardiomyocyte culture46,47.</td>
		</tr>
		<tr>
			<td>Collagenase/Dispase</td>
			<td>Roche</td>
			<td>10269638001</td>
			<td>can be substituted with collagenase type II from Worthington</td>
		</tr>
		<tr>
			<td>Collagenase type II3</td>
			<td>Worthington</td>
			<td>CLS-2</td>
			<td>substitute for Collagenase/Dispase mix from Roche</td>
		</tr>
		<tr>
			<td>1x trypsin solution (0.25%) with EDTA</td>
			<td>e.g. cellgro</td>
			<td>25-053-CI</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1x Penicillin/ Streptomycin solution with EDTA in HBSS</td>
			<td>e.g. cellgro</td>
			<td>30-002-Cl</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1x PBS (without Ca2+, Mg2+)</td>
			<td>e,g, cellgro</td>
			<td>21-040-CV</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>HBSS (Hank's balanced salt solution; without Ca2+, Mg2+) 4</td>
			<td>e.g. cellgro</td>
			<td>21-022-CV</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>DMEM high glucose</td>
			<td>e.g. cellgro</td>
			<td>10-013-CV</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>M-199</td>
			<td>e.g. cellgro</td>
			<td>10-060-CV</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>fetal bovine serum</td>
			<td>e.g. cellgro</td>
			<td>35-011-CV</td>
			<td>cell-culture grade</td>
		</tr>
		<tr>
			<td>horse serum</td>
			<td>e.g. cellgro</td>
			<td>35-030-CV</td>
			<td>cell-culture grade</td>
		</tr>
		<tr>
			<td>Leibovitz L-155</td>
			<td>e.g. cellgro</td>
			<td>10-045-CV</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>AraC (Cytosine-B-D-arabino-furanoside hydrochloride)</td>
			<td>Sigma</td>
			<td>C-6645</td>
			<td>proliferation inhibitor, prepare 1 mM stock solution in H2O, filter sterilize, store at 4 &deg;C</td>
		</tr>
		<tr>
			<td>phenylephrine</td>
			<td>Sigma</td>
			<td>P-6126</td>
			<td>chronotropic agent, prepare 100 mM stock solution in H2O, filter sterilize, store at 4 &deg;C or -20 &deg;C</td>
		</tr>
		<tr>
			<td>isoproterenol hydrochloride</td>
			<td>Sigma</td>
			<td>I-6501</td>
			<td>chronotropic agent, prepare 1 mM stock solution in H2O, filter sterilize, store at 4 &deg;C or -20 &deg;C</td>
		</tr>
		<tr>
			<td>0.1% collagen solution</td>
			<td>Sigma</td>
			<td>C-8919</td>
			<td>extracellular matrix for coating</td>
		</tr>
		<tr>
			<td>3 mg/ml collagen type 1 solution</td>
			<td>Advanced BioMatrix</td>
			<td>5005-B</td>
			<td>alternative to Sigma collagen solution</td>
		</tr>
		<tr>
			<td>cell strainer</td>
			<td>e.g. Fisherbrand</td>
			<td>22363548</td>
			<td>appropriate filter size:40 &mu;m-100 &mu;m</td>
		</tr>
		<tr>
			<td>syringe filter 0.2 &mu;m</td>
			<td>e.g. Fisherbrand</td>
			<td>09-719C</td>
			<td>for sterile filtration of digestion medium</td>
		</tr>
		<tr>
			<td>straight scissors</td>
			<td>e.g. Fine Sciences Tools</td>
			<td>91460-11</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>curved scissors</td>
			<td>e.g. Fine Science Tools</td>
			<td>91461-11</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Dumont No. 7 forceps</td>
			<td>e.g. Fine Science Tools</td>
			<td>91197-00</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>perforated spoon</td>
			<td>e.g. Fine Science Tools</td>
			<td>10370-19</td>
			<td>optional, for transfer of heart tissue</td>
		</tr>
		<tr>
			<td>Trypan blue</td>
			<td>e.g. Gibco</td>
			<td>15250-061</td>
			<td>live cell staining</td>
		</tr>
		<tr>
			<td>Neubauer hemocytometer</td>
			<td>e.g. Prosource Scientific</td>
			<td>3500</td>
			<td>alternatively use: disposable hemocytometer C-chip or automated cell counting systems</td>
		</tr>
		<tr>
			<td>50 ml Falcon tubes</td>
			<td>e.g. Fisherbrand</td>
			<td>14-432-23</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>15 ml Falcon tubes</td>
			<td>e.g. Fisherbrand</td>
			<td>05-527-90</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>20 ml syringe</td>
			<td>e.g. BD Medical</td>
			<td>14-820-19</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>10 ml serological pipette</td>
			<td>e.g. Falcon</td>
			<td>357551</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>30 mm cell culture dish</td>
			<td>e.g. Nunc</td>
			<td>153066</td>
			<td>for standard culture of cardiomyocytes</td>
		</tr>
		<tr>
			<td>30 mm cell culture dish, glass bottom</td>
			<td>MatTek</td>
			<td>P35G-0-10-C</td>
			<td>for live cell imaging with inverted microscope</td>
		</tr>
		<tr>
			<td>10 cm cell culture dish</td>
			<td>e.g. Nunc</td>
			<td>172958</td>
			<td>for preplating</td>
		</tr>
		<tr>
			<td>Escort III</td>
			<td>Sigma</td>
			<td>L3037</td>
			<td>for liposomal transfection, alternatively use lipofectamin 2000</td>
		</tr>
		<tr>
			<td>Lipofectamine 2000</td>
			<td>Life Technologies, Invitrogen</td>
			<td>52887</td>
			<td>substitute for Escort III</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Buffers and media: 
			<ul>
				<li>Isolation medium (filter sterilize) 
				20 mM BDM 
				0.0125% trypsin 
				in HBSS4 (without Ca2+, Mg2+)</li>
				<li>Digestion medium (filter sterilize) 
				20 mM BDM 
				1.5 mg/ml Roche Collagenase/Dispase enzyme mix 
				in L15 medium</li>
				<li>Plating medium 
				65% DMEM high glucose 
				19% M-199 
				10% horse serum 
				5% fetal calf serum 
				1% penicillin/streptomycin</li>
				<li>Maintenance medium 
				78% DMEM high glucose 
				17% M-199 
				4% horse serum 
				1% penicillin/streptomycin 
				optional: 
				1 &mu;M AraC 
				1 &mu;M isoproterenol or 0.1 mM phenylephrine</li>
			</ul>
			The plating and maintenance medium can be stored at 4 &deg;C for up to 6 months.</td>
		</tr>
	</tbody>
</table>

isolation and culture of neonatal mouse cardiomyocytes

Cultured neonatal cardiomyocytes have long been used to study myofibrillogenesis and myofibrillar functions. Cultured cardiomyocytes allow for easy investigation and manipulation of biochemical pathways, and their effect on the biomechanical properties of spontaneously beating cardiomyocytes.	
The following 2-day protocol describes the isolation and culture of neonatal mouse cardiomyocytes. We show how to easily dissect hearts from neonates, dissociate the cardiac tissue and enrich cardiomyocytes from the cardiac cell-population. We discuss the usage of different enzyme mixes for cell-dissociation, and their effects on cell-viability. The isolated cardiomyocytes can be subsequently used for a variety of morphological, electrophysiological, biochemical, cell-biological or biomechanical assays. We optimized the protocol for robustness and reproducibility, by using only commercially available solutions and enzyme mixes that show little lot-to-lot variability. We also address common problems associated with the isolation and culture of cardiomyocytes, and offer a variety of options for the optimization of isolation and culture conditions.

Using this protocol, we isolated hearts from 8 one day old neonatal mice (Figures 1A, 1B, Supplemental Movie S1). After washing and mincing the hearts with scissors (Figures 1C-1F), tissue fragments were predigested in isolation medium over night at 4 &deg;C with gentle agitation. Following predigestion (Figure 1G), we transferred the tissue fragments into freshly made digestion medium, and incubated the tissue fragments for 20 min at 37 &deg;C with gentle agitation. The...

Watch this Scientific Journal Video about Isolation and Culture of Neonatal Mouse Cardiomyocytes at JoVE.com

Isolation and Culture of Neonatal Mouse Cardiomyocytes

Primary mouse cardiomyocyte cultures are one of the pivotal tools for the investigation of myofibrillar organization and function. The following protocol describes the isolation and culture of primary cardiomyocytes from neonatal mouse hearts. The resulting cardiomyocyte cultures may be subsequently used for a variety of biomechanical, biochemical and cell-biological assays.

Cultured neonatal cardiomyocytes have long been used to study  myofibrillogenesis and myofibrillar functions. Cultured cardiomyocytes allow  for easy ...

isolation-and-culture-of-neonatal-mouse-cardiomyocytes

Research

JoVE Journal

Biology

62.3K Aufrufe.  King’s College London.  Primäre Maus-Kardiomyozyten-Kulturen sind eines der zentralen Werkzeuge für die Untersuchung von myofibrillären Organisation und Funktion. Das folgende Protokoll beschreibt die Isolierung und Kultur von primären Kardiomyozyten aus neonatalen Mäuseherzen. Die resultierenden Kulturen Kardiomyozyten können anschließend für eine Vielzahl von biomechanischen, biochemischen und zellbiologischen Assays verwendet werden. 

Serie: Isolation and Culture of Neonatal Mouse Cardiomyocytes

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 Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes

KCNE genes encode for a small family of Kv channel ancillary subunits that form heteromeric complexes with Kv channel alpha subunits to modify their functional properties. Mutations in KCNE genes have been found in patients with cardiac arrhythmias such as the long QT syndrome and/or atrial fibrillation. However, the precise molecular pathophysiology that leads to these diseases remains elusive. In previous studies the electrophysiological properties of the disease causing mutations in these genes have mostly been studied in heterologous expression systems and we cannot be sure if the reported effects can directly be translated into native cardiomyocytes. In our laboratory we therefore use a different approach. We directly study the effects of KCNE gene deletion in isolated cardiomyocytes from knockout mice by cellular electrophysiology - a unique technique that we describe in this issue of the Journal of Visualized Experiments. The hearts from genetically engineered KCNE mice are rapidly excised and mounted onto a Langendorff apparatus by aortic cannulation. Free Ca2+ in the myocardium is bound by EGTA, and dissociation of cardiac myocytes is then achieved by retrograde perfusion of the coronary arteries with a specialized low Ca2+ buffer containing collagenase. Atria, free right ventricular wall and the left ventricle can then be separated by microsurgical techniques. Calcium is then slowly added back to isolated cardiomyocytes in a multiple step comprising washing procedure. Atrial and ventricular cardiomyocytes of healthy appearance with no spontaneous contractions are then immediately subjected to electrophysiological analyses by patch clamp technique or other biochemical analyses within the first 6 hours following isolation.

Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays.

KCNE genes encode for a small family of Kv channel ancillary subunits that form heteromeric complexes with Kv channel alpha subunits to modify their ...

Isolation, Culture, and Functional Characterization of Adult Mouse Cardiomyoctyes

The use of primary cardiomyocytes (CMs) in culture has provided a powerful complement to murine models of heart disease in advancing our understanding of heart disease. In particular, the ability to study ion homeostasis, ion channel function, cellular excitability and excitation-contraction coupling and their alterations in diseased conditions and by disease-causing mutations have led to significant insights into cardiac diseases. Furthermore, the lack of an adequate immortalized cell line to mimic adult CMs, and the limitations of neonatal CMs (which lack many of the structural and functional biomechanics characteristic of adult CMs) in culture have hampered our understanding of the complex interplay between signaling pathways, ion channels and contractile properties in the adult heart strengthening the importance of studying adult isolated cardiomyocytes. Here, we present methods for the isolation, culture, manipulation of gene expression by adenoviral-expressed proteins, and subsequent functional analysis of cardiomyocytes from the adult mouse. The use of these techniques will help to develop mechanistic insight into signaling pathways that regulate cellular excitability, Ca2+ dynamics and contractility and provide a much more physiologically relevant characterization of cardiovascular disease.

Here we describe the isolation of adult mouse cardiomyoctyes using a Langendorff perfusion system. The resulting cells are Ca2+-tolerant, electrically quiescent and can be cultured and transfected with adeno- or lentiviruses to manipulate gene expression. Their functionality can also be analyzed using the MMSYS system and patch clamp techniques.

The use of primary cardiomyocytes (CMs) in culture has provided a powerful complement to murine models of heart disease in advancing our understanding of ...

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 and Physiological Analysis of Mouse Cardiomyocytes

Cardiomyocytes, the workhorse cell of the heart, contain exquisitely organized cytoskeletal and contractile elements that generate the contractile force used to pump blood. Individual cardiomyocytes were first isolated over 40 years ago in order to better study the physiology and structure of heart muscle. Techniques have rapidly improved to include enzymatic digestion via coronary perfusion. More recently, analyzing the contractility and calcium flux of isolated myocytes has provided a vital tool in the cellular and sub-cellular analysis of heart failure. Echocardiography and EKGs provide information about the heart at an organ level only. Cardiomyocyte cell culture systems exist, but cells lack physiologically essential structures such as organized sarcomeres and t-tubules required for myocyte function within the heart. In the protocol presented here, cardiomyocytes are isolated via Langendorff perfusion. The heart is removed from the mouse, mounted via the aorta to a cannula, perfused with digestion enzymes, and cells are introduced to increasing calcium concentrations. Edge and sarcomere detection software is used to analyze contractility, and a calcium binding fluorescent dye is used to visualize calcium transients of electrically paced cardiomyocytes; increasing understanding of the role cellular changes play in heart dysfunction. Traditionally used to test drug effects on cardiomyocytes, we employ this system to compare myocytes from WT mice and mice with a mutation that causes dilated cardiomyopathy. This protocol is unique in its comparison of live cells from mice with known heart function and known genetics. Many experimental conditions are reliably compared, including genetic or environmental manipulation, infection, drug treatment, and more. Beyond physiologic data, isolated cardiomyocytes are easily fixed and stained for cytoskeletal elements. Isolating cardiomyocytes via perfusion is an extremely versatile method, useful in studying cellular changes that accompany or lead to heart failure in a variety of experimental conditions.

Individual cardiomyocytes from wild type and mutant mice can be isolated from the heart in order to study their contractility and calcium transients. This allows characterization of the contribution of cellular dysfunction to heart dysfunction from any cause.

Cardiomyocytes, the workhorse cell of the heart, contain exquisitely organized cytoskeletal and contractile elements that generate the contractile force ...

Isolation and Culture of Adult Mouse Cardiomyocytes for Cell Signaling and in vitro Cardiac Hypertrophy

Technological advances have made genetically modified mice, including transgenic and gene knockout mice, an essential tool in many research fields. Adult cardiomyocytes are widely accepted as a good model for cardiac cellular physiology and pathophysiology, as well as for pharmaceutical intervention. Genetically modified mice preclude the need for complicated cardiomyocyte infection processes to generate the desired genotype, which are inefficient due to cardiomyocytes&#8217; terminal differentiation. Isolation and culture of high quantity and quality functional cardiomyocytes will dramatically benefit cardiovascular research and provide an important tool for cell signaling transduction research and drug development. Here, we describe a well-established method for isolation of adult mouse cardiomyocytes that can be implemented with little training. The mouse heart is excised and cannulated to an isolated heart system, then perfused with a calcium-free and high potassium buffer followed by type II collagenase digestion in Langendorff retrograde perfusion mode. This protocol yields a consistent result for the collection of functional adult mouse cardiomyocytes from a variety of genetically modified mice.

Isolation and Culture of Adult Mouse Cardiomyocytes for Cell Signaling and in vitro Cardiac Hypertrophy

We describe a reliable method for isolation of adult mouse cardiomyocytes. This protocol yields a consistent result for the culture of functional adult cardiomyocytes from a variety of genetically modified mice.

Technological advances have made genetically modified mice, including transgenic and gene knockout mice, an essential tool in many research fields. Adult ...

Isolation of Neonatal Extrahepatic Cholangiocytes

The intra and extrahepatic bile ducts of the liver are developmentally distinct, and may be differentially affected by certain diseases. However, differences between intra and extrahepatic cholangiocytes, and between neonatal and adult cells, are not well understood.
Methods for the isolation of cholangiocytes from intrahepatic bile ducts are well established1-4. Isolation of extrahepatic ductal cells, especially from the neonate, has not yet been described, although this would be of great benefit in understanding the differences between distinct cholangiocyte populations and in studying diseases such as biliary atresia that appear to target the extrahepatic ducts. Described here is an optimized technique to isolate both neonatal and adult mouse extrahepatic bile duct cells. This technique yields a pure cell population with minimal contamination from mesenchymal cells like fibroblasts.
This method is based on the removal of the extrahepatic ducts and gallbladder, followed by meticulous dissection and scraping to remove fat and fibroblast layers. Structures are embedded in thick layers of collagen and cultured for approximately 3 weeks to allow outgrowth of cholangiocytes in monolayers, which can then be trypsinized and re plated for experimental use.

A technique to isolate cholangiocytes from the extrahepatic bile ducts of neonatal mice is described. The ducts are meticulously dissected, and then cells are isolated by outgrowth in thick collagen gels. This method provides a useful tool for studying extrahepatic bile duct development and pathology.

The intra and extrahepatic bile ducts of the liver are developmentally distinct, and may be differentially affected by certain diseases. However, ...

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 ...

Isolation, Culture and Transduction of Adult Mouse Cardiomyocytes

Cultured cardiomyocytes can be used to study cardiomyocyte biology using techniques that are complementary to in vivo systems. For example, the purity and accessibility of in vitro culture enables fine control over biochemical analyses, live imaging, and electrophysiology. Long-term culture of cardiomyocytes offers access to additional experimental approaches that cannot be completed in short term cultures. For example, the in vitro investigation of dedifferentiation, cell cycle re-entry, and cell division has thus far largely been restricted to rat cardiomyocytes, which appear to be more robust in long-term culture. However, the availability of a rich toolset of transgenic mouse lines and well-developed disease models make mouse systems attractive for cardiac research. Although several reports exist of adult mouse cardiomyocyte isolation, few studies demonstrate their long-term culture. Presented here, is a step-by-step method for the isolation and long-term culture of adult mouse cardiomyocytes. First, retrograde Langendorff perfusion is used to efficiently digest the heart with proteases, followed by gravity sedimentation purification. After a period of dedifferentiation following isolation, the cells gradually attach to the culture and can be cultured for weeks. Adenovirus cell lysate is used to efficiently transduce the isolated cardiomyocytes. These methods provide a simple, yet powerful model system to study cardiac biology.

This protocol describes a step-by-step method for the reproducible isolation and long-term culture of adult mouse cardiomyocytes with high yield, purity, and viability.

Cultured cardiomyocytes can be used to study cardiomyocyte biology using techniques that are complementary to in vivo systems. For example, the purity and ...

Isolation and Culture of Primary Mouse Keratinocytes from Neonatal and Adult Mouse Skin

The keratinocyte (KC) is the predominant cell type in the epidermis, the outermost layer of the skin. Epidermal KCs play a critical role in providing skin defense by forming an intact skin barrier against environmental insults, such as UVB irradiation or pathogens, and also by initiating an inflammatory response upon those insults. Here we describe methods to isolate KCs from neonatal mouse skin and from adult mouse tail skin. We also describe culturing conditions using defined growth supplements (dGS) in comparison to chelexed fetal bovine serum (cFBS). Functionally, we show that both neonatal and adult KCs are highly responsive to high calcium-induced terminal differentiation, tight junction formation and stratification. Additionally, cultured adult KCs are susceptible to UVB-triggered cell death and can release large amounts of TNF upon UVB irradiation. Together, the methods described here will be useful to researchers for the setup of in vitro models to study epidermal biology in the neonatal mouse and/or the adult mouse.

Epidermal keratinocytes form a functional skin barrier and are positioned at the front line of host defense against external environmental insults. Here we describe methods for isolation and primary culture of epidermal keratinocytes from neonatal and adult mouse skin, and induction of terminal differentiation and UVB-triggered inflammatory response from keratinocytes.

The keratinocyte (KC) is the predominant cell type in the epidermis, the outermost layer of the skin. Epidermal KCs play a critical role in providing skin ...