Isolation and Cultivation of Adult Rat Cardiomyocytes

Summary

Here, we present a protocol for the isolation and cultivation of adult rat ventricular cardiomyocytes (ARVC). Isolated ARVC can be used for short and long-term cultivation. The isolation and cultivation of ARVC can play a key role in developing new treatment regimens for cardiac diseases.

Abstract

In an intact heart, adjacent cells influence adult cardiomyocytes. With the method of isolation and cultivation of adult cardiomyocytes, a precise investigation of the behavior of these cells under specific treatments and environments is possible. This manuscript presents a protocol for successful isolation and cultivation of adult rat ventricular cardiomyocytes (ARVC).

The rat is sacrificed by cervical dislocation under deep anesthesia. Then, the heart is extracted and the aorta is uncovered. Subsequently, perfusion on the Langendorff perfusion system with calcium depletion and collagenase treatment is performed. Afterwards, ventricular tissue gets minced, re-circulated, and filtered, followed by three centrifugation steps with gradual addition of CaCl₂ until physiological calcium concentration is reached. ARVC are plated on cell culture dishes. After refreshing the cell culture medium, ARVC can be cultivated for up to six days without changing the serum-containing culture medium. Isolation of ARVC is a calcium sensitive process. Small changes in the intracellular calcium concentration cause a decrease in the quality and viability of the isolated cells.

Freshly isolated ARVC are rod shaped. Within the first days of cultivation they lose the rod-shaped morphology and form pseudopodia-like structures (spreading). During this morphological formation ARVC initially degrade their contractile elements followed by a reformation through actin stress fibers and de novo sarcomerogenesis. After one week of cultivation, most ARVC show a widespread appearance with a clearly detectable cross striation. This process is sensitive to intracellular calcium concentration, as treatment with ionomycin attenuates spreading. Key markers in this process of de- and re-differentiation are β-myosin heavy chain (β-MHC), oncostatin M (OSM), and swiprosin-1 (EFHD2). Recent studies have suggested that cardiac re- and de-differentiation occurring under culture conditions mimics features seen in vivo during cardiac remodeling. Therefore, isolation and cultivation of ARVC play a key role in understanding the biology of cardiomyocytes.

Introduction

Adult cardiomyocytes in vivo work as an electrical syncytium based on cell-cell contacts between myocytes. In addition, they are influenced by adjacent cells like cardiac fibroblasts, endothelial cells, neurons, and inflammatory cells¹. In order to study the ability of cardiomyocytes to adapt their intracellular organization to altered load conditions, as seen during cardiac hypertrophy, which is an initial step leading to heart failure, the isolation and cultivation of adult ventricular rat cardiomyocytes (ARVC) is necessary^2,3,4. Historicall....

Protocol

The investigation is conducted according to the Guide for the Care and Use of Laboratory Animals published by the US National Institute of Health (NIH Publication No. 85-23, revised 1996). In general, male wistar rats aged 3 to 4 months and with an average weight of 250 - 350 g are used for this protocol. One rat heart is sufficient for 20 culture dishes (1 mL per dish; inner diameter: 35 mm) with an approximate cell density of 1.5 x 10⁴ cells/1000 mm².

1. Preparation of Media and Reagents

1. Creatine-carnitine-taurine medium (CCT medium)
   NOTE: CCT medium is a complex medium based on me....

Results

Adult cardiomyocytes in culture: Figure 1 shows an overview of freshly isolated adult cardiomyocytes 2 h after the last washing. Approximately 75% of all cardiomyocytes had a rod-shaped morphology. The remaining 25% showed an unusual appearance with a round morphology and no detectable intact cell membrane (Figure 1). At the end of cultivation (day 6), up to 15% of all cardiomyocytes showed spreading, about 10% r.......

Discussion

The behavior of adult cardiomyocytes in vivo is influenced by many interactions with other cells (e.g., neurons, endothelial cells, fibroblasts, inflammatory cells) and the electrical syncytium which they form¹. Therefore, studying stress adaptation of adult cardiomyocytes exclusively requires the isolation and cultivation of ARVC. The main effects of isolating and cultivating ARVC are: 1) disconnecting them from extracellular matrix and cell-cell contacts; 2) disconnecting them .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Langendorff perfusion system	inhouse construction		double-walled with a water based heating system
Tissue chopper Mc Ilwain	Cavey Laboratory Engeneering Co. Ltd.
Aortic Cannula, OD 1,8 mm	inhouse construction
Abdominal shears	Aeskulap	BC772R
Capsule forceps	Eickemeyer	171307
Dissecting scissor large	Aeskulap	BC562R
Dissecting scissor small	Aeskulap	BC163R
Mash with Polyamid	Neolab	4-1413	mash size 200 μm
plastic disc	Cavey Laboratory Engeneering Co. Ltd.
Collagenase Typ II	Worthington	LS004177