title: Excitation propagation in three-dimensional engineered hearts using decellularized extracellular matrix.
abstract: Engineering of three-dimensional (3D) cardiac tissues using decellularized extracellular matrix could be a new technique to create an "organ-like" structure of the heart. To engineer artificial hearts functionally comparable to native hearts, however, much remain to be solved including stable excitation-propagation. To elucidate the points, we examined conduction properties of engineered tissues. We repopulated the decellularized hearts with neonatal rat cardiac cells and then, we observed excitation-propagation of spontaneous beatings using high resolution cameras. We also conducted immunofluorescence staining to examine morphological aspects. Live tissue imaging revealed that GFP-labeled-isolated cardiac cells were migrated into interstitial spaces through extravasation from coronary arteries. Engineered hearts repopulated with Ca(2+)-indicating protein (GCaMP2)-expressing cardiac cells were subjected to optical imaging experiments. Although the engineered hearts generally showed well-organized stable excitation-propagation, the hearts also demonstrated arrhythmogenic propensity such as disorganized propagation. Immunofluorescence study revealed randomly-mixed alignment of cardiomyocytes, endothelial cells and smooth muscle cells. The recellularized hearts also showed disarray of cardiomyocytes and markedly decreased expression of connexin43. In conclusion, we successfully demonstrated that the recellularized hearts showed dynamic excitation-propagation as a "whole organ". Our strategy could provide prerequisite information to construct a 3D-engineered heart, functionally comparable to the native heart.
authors: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Japan.
authors: Haruyo
authors: H
authors: Yasui
authors: Department of Cardiovascular Regenerative Medicine, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita 565-0871, Japan. Electronic address: jlee@cardiology.med.osaka-u.ac.jp.
authors: Jong-Kook
authors: JK
authors: Lee
authors: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Japan.
authors: Akira
authors: A
authors: Yoshida
authors: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Japan.
authors: Teruki
authors: T
authors: Yokoyama
authors: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Japan.
authors: Hiroyuki
authors: H
authors: Nakanishi
authors: Department of Cardiovascular Regenerative Medicine, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita 565-0871, Japan.
authors: Keiko
authors: K
authors: Miwa
authors: Department of Cardiovascular Medicine, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors: Atsuhiko T
authors: AT
authors: Naito
authors: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Japan.
authors: Toru
authors: T
authors: Oka
authors: Department of Cardiovascular Medicine, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors: Hiroshi
authors: H
authors: Akazawa
authors: Saitama University Brain Science Institute, Japan.
authors: Junichi
authors: J
authors: Nakai
authors: Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Japan.
authors: Shigeru
authors: S
authors: Miyagawa
authors: Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Japan.
authors: Yoshiki
authors: Y
authors: Sawa
authors: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Japan.
authors: Yasushi
authors: Y
authors: Sakata
authors: Department of Cardiovascular Medicine, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors: Issei
authors: I
authors: Komuro
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D002118:Calcium / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006321:Heart / Q000502:physiology*; D009206:Myocardium / Q000648:ultrastructure; D032383:Myocytes, Cardiac / Q000166:cytology / Q000637:transplantation; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D049452:Green Fluorescent Proteins; D002118:Calcium
keywords: Cardiac tissue engineering; ECM (extracellular matrix); Electrophysiology; Organ culture; Scaffold