Cardiac stem cell populations for repair of cardiac tissue

Abstract

Method for the isolation, expansion and preservation of cardiac stem cells from human or animal tissue biopsy samples to be employed in cell transplantation and functional repair of the myocardium or other organs. Cells may also be used in gene therapy for treating cardiomyopathies, for treating ischemic heart diseases and for setting in vitro models to study drugs.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. application Ser. No. 10 / 567,008 filed Jul. 13, 2006 which is the U.S. National Phase application under 35 U.S.C. §371 of International Application PCT / IT2004 / 000421 filed Jul. 29, 2004, which claims priority to Italian Application RM2003 A 000376, filed Jul. 31, 2003. The entirety of each of these applications is hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention concerns a method for the isolation and expansion of cardiac stem cells derived from postnatal cardiac tissue biopsy.[0004]The invention deals with a method for the isolation, expansion and preservation of cardiac stem cells from human or animal tissue biopsy samples to be employed in cell transplantation and functional repair of the myocardium or other organs.[0005]The cells may also be used in gene therapy, for treating genetic cardiomyopathies by expressing the healthy gene i...

AI Technical Summary

Benefits of technology

[0020]These cells are able to multiply, while maintaining their origin characteristics for a period (at least 60 days) that is long enough to markedly enrich the cell population. Mechanical disaggregation of the cardiospheres (CS) by repeated pipetting and changing the medium every 3 days increases the number of CS (about 100-fold every 10 days) for at least the first 20 days. Given the number of SC that can be derived from a biopsy and their ability to multiply in vitro, it is thought that they can be used to replace a greater amount of tissue than that removed.

[0041]Experts in the field will understand that the CS derived with the procedure of the invention may be able to generate continuous cell lines following spontaneous transformation or transformation induced by chemical, physical or biologic agents.

Problems solved by technology

The limited ability of adult cardiomyocytes to undergo mitosis and to regenerate the myocardium after injury leads to a permanent deficiency in the number of functioning cells, with the development and progression of cardiac insufficiency.

However, the problem of having a source and an availability of SC remains (5-7).

While embryonic SC (undifferentiated cells from the embryo that can produce a wide range of specialized cells and that can be derived from the cell mass inside blastocytes which, in humans, form 4-5 days after fertilization of the ovum) have a marked capability to proliferate and differentiate, their potential immunogenicity, arrhythmogenicity, and ethical issues in particular, have limited their use.

Moreover, embryonic SC are pluripotent, consequently their use carries a potential risk of generating teratomas (as occurs in animal models).

Embryonic SC have the potential capability to generate these cardiomyocyte phenotypes in vitro but the yield is insufficient.

Furthermore, the in vivo proliferative capability of cardiomyocytes derived from embryonic SC appears to be limited by the growth of multinucleate cells.

The inability of skeletal myoblasts to transdifferentiate into cardiomyocytes and to couple with them could give rise to arrhythmias or other anomalies

But the functional and electrophysiologic properties of HSC- and MSC-derived cardiomyocytes are not well characterized, and the use of undifferentiated cells instead of cardiomyocytes could give rise to in vivo differentiation into fibroblasts rather than muscle cells or to the development of tumors.

Furthermore, there is no in vivo evidence from cardiomyopathic animals that supports the applicability of the method.

Adherent cells cloned by limiting dilution give rise to mesenchymal cells, including osteoblasts, chondrocytes, adipocytes and myocytes, although they cannot be clearly identified due to often inappropriate morphologic criteria and markers.

However, no data are given about the characteristics of the isolated SC.

Furthermore, the cells isolated with the previous method do not give rise to the formation of an essential component of the heart tissues, i.e. vessels and endothelium.

Images