METHODS AND MATERIALS FOR USING CELLS TO TREAT HEART TISSUE

BACKGROUND I. Technical Field

This document relates to methods and materials involved in obtaining cardiac cells. For example, this document relates to methods and materials for providing mammalian heart tissue with cells (e.g., differentiated cardioprogenitor cells) that incorporate into the heart tissue as functional cardiomyocytes.

2. Background Information

Cardiovascular disease is a leading cause of morbidity and mortality worldwide, despite advances in patient management (Towbin and Bowles, Nature, 415:227-233 (2002)). In contrast to tissues with high reparative capacity, heart tissue is vulnerable to irreparable damage (Anversa and Nadal-Ginard, Nature, 415 :240-243 (2002)). Cell- based regenerative cardiovascular medicine is, therefore, being pursued in the clinical setting (Dimmeler et al., JClin Invest, 115:572-583 (2005); Wollert and Drexler, Circ Res, 96:151-163 (2005); Caplice et al, Nat Clin Pract Cardiovasc Med, 2:37-43 (2005)).

SUMMARY

This document provides methods and materials relating to cardiac cells. For example, this document provides methods and materials that can be used to obtain cells (e.g., differentiated cardioprogenitor cells) having the ability to incorporate into heart tissue as functional cardiomyocytes. Such cells can be used to repair damaged heart tissue. For example, cells having the ability to incorporate into heart tissue as functional cardiomyocytes can be used to repair or regenerate heart tissue in patients with a cardiac condition (e.g., ischemic cardiomyopathy, myocardial infarction, or heart failure).

In general, one aspect of this document features a method for obtaining differentiated cells expressing an elevated level of MEF2c mRNA, MESP-I mRNA, Tbx- 5 mRNA, GATA6 mRNA, or Fog 2 mRNA. The method comprises, or consists essentially of, culturing mesenchymal stem cells in the presence of medium comprising,

or consisting essentially of, TGFβ-1, BMP4, cardiotrophin, α-thrombin, and cardiogenol C under conditions wherein the mesenchymal stem cells differentiate into the differentiated cells. The mesenchymal stem cells can be human mesenchymal stem cells. The method can comprise obtaining differentiated cells expressing an elevated level of MEF2c mRNA and MESP-I mRNA. The method can comprise obtaining differentiated cells expressing an elevated level of MEF2c mRNA, MESP-I mRNA, Tbx-5 mRNA, GAT A6 mRNA, and Fog 2 mRNA. The mesenchymal stem cells can express CD 105, CD 166, CD29, and CD44 on the cell surface. The mesenchymal stem cells can lack expression of CD 14, CD34, and CD45 on the cell surface. The medium can comprise serum. The medium can comprise fetal calf serum. The medium can comprise a platelet lysate. The medium can comprise FGF2, IGF-I, or activin-A. The medium can comprise FGF2, IGF-I, and activin-A. The medium can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, or retinoic acid. The medium can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, and retinoic acid. In another aspect, this document features a method for delivering differentiated cells to a mammal. The method comprises, or consists essentially of, (a) determining that a sample of cells from a population of differentiated cells obtained from mesenchymal stem cells comprises cells that express an elevated level of MEF2c mRNA, MESP-I mRNA, Tbx-5 mRNA, GATA6 mRNA, or Fog2 mRNA, and (b) administering cells from the population of differentiated cells to the mammal. The step (a) can comprise determining that the sample of cells comprises cells that express an elevated level of MEF2c mRNA, MESP-I mRNA, Tbx-5 mRNA, GATA6 mRNA, and Fog2 mRNA. The population of differentiated cells can be obtained from mesenchymal stem cells cultured in the presence of medium comprising TGFβ-1, BMP4, cardiotrophin, α-thrombin, and cardiogenol C. The medium can comprise serum. The medium can comprise fetal calf serum. The medium can comprise a platelet lysate. The medium can comprise FGF2, IGF-I, or activin-A. The medium can comprise FGF2, IGF-I, and activin-A. The medium can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, or retinoic acid. The medium can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, and retinoic acid. The mesenchymal stem cells can express CD105, CD166, CD29, and CD44 on the cell surface. The mesenchymal stem cells can lack expression of CD 14, CD34, and CD45 on the cell surface. The step

(a) can comprise using a reverse transcription polymerase chain reaction. The administering step can comprise administering about 300,000 to about 3,000,000 cells to the mammal. The administering step can comprise administering the cells via a systemic administration. The administering step can comprise administering the cells via an intracardiac administration.

In another aspect, this document features a method for delivering differentiated cells to a mammal. The method comprises, or consists essentially of, (a) determining that a sample of cells from a population of differentiated cells obtained from mesenchymal stem cells comprises cells having Nkx2.5 polypeptides associated with the nuclei of the cells or MEF2C polypeptides associated with the nuclei of the cells, and (b) administering cells from the population of differentiated cells to the mammal. The step (a) can comprise determining that the sample of cells comprises cells having Nkx2.5 polypeptides associated with the nuclei of the cells and MEF2C polypeptides associated with the nuclei of the cells. The population of differentiated cells can be obtained from mesenchymal stem cells cultured in the presence of medium comprising TGFβ-1, BMP4, cardiotrophin, α-thrombin, and cardiogenol C. The medium can comprise serum. The medium can comprise fetal calf serum. The medium can comprise a platelet lysate. The medium can comprise FGF2, IGF-I, or activin-A. The medium can comprise FGF2, IGF-I, and activin-A. The medium can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, or retinoic acid. The medium can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, and retinoic acid. The mesenchymal stem cells can express CD 105, CD 166, CD29, and CD44 on the cell surface. The mesenchymal stem cells can lack expression of CD14, CD34, and CD45 on the cell surface. The step (a) can comprise using immunocytochemistry. The administering step can comprise administering about 300,000 to about 3,000,000 cells to the mammal. The administering step can comprise administering the cells via a systemic administration. The administering step can comprise administering the cells via an intracardiac administration.

In another aspect, this document features a method for providing heart tissue with cardiomyocytes. The method comprises, or consists essentially of, administering, to the heart tissue, cells obtained by contacting stem cells with a composition, wherein the

composition comprises, or consists essentially of, TGFβ-1, BMP4, cardiotrophin, α- thrombin, and cardiogenol C.

In another aspect, this document features a composition comprising, consisting essentially of, TGFβ-1, BMP4, cardiotrophin, α-thrombin, and cardiogenol C. The composition can comprise between 1 and 5 ng of the TGFβ-1 per mL, between 1 and 10 ng of the BMP4 per mL, between 0.5 and 5 ng of the cardiotrophin per mL, between 0.5 and 5 units of the α-thrombin per mL, and between 50 and 500 nM of the cardiogenol C. The composition can comprise FGF2, IGF-I, and activin-A. The composition can comprise between 1 and 10 ng of the FGF2 per mL, between 10 and 100 ng of the IGF-I per mL, between 1 and 50 ng of the activin-A per mL. The composition can comprise TNF-α, FGF-4, IL-6, LIF, VEGF-A, or retinoic acid. The composition can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, or retinoic acid. The composition can lack TNF-α, FGF-4, IL-6, LIF, VEGF-A, and retinoic acid.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and from the claims.

DETAILED DESCRIPTION

This document provides methods and materials related to cardiac cells (e.g., differentiated cardioprogenitor cells). For example, this document provides cells having the ability to incorporate into heart tissue as functional cardiomyocytes, methods for making such cells, compositions for making such cells, and methods for determining whether or not a population of cells (e.g., differentiated cardioprogenitor cells) contains

cells having the ability to incorporate into heart tissue as functional cardiomyocytes. This document also provides methods and materials for providing heart tissue (e.g., human heart tissue) with functional cardiomyocytes.

The differentiated cardioprogenitor cells provided herein can be from any species including, without limitation, humans, monkeys, horses, dogs, cats, rats, or mice. For example, differentiated cardioprogenitor cells can be mammalian (e.g., human) differentiated cardioprogenitor cells. In some cases, differentiated cardioprogenitor cells provided herein have the ability to incorporate into heart tissue as functional cardiomyocytes. Any appropriate method can be used to obtain differentiated cardioprogenitor cells. For example, differentiated cardioprogenitor cells can be derived from stem cells such as mammalian (e.g., human) stem cells. In some cases, differentiated cardioprogenitor cells can be derived from embryonic stem cells. In some cases, differentiated cardioprogenitor cells can be derived from mesenchymal stem cells. Mesenchymal stem cells can be obtained from any source. For example, mesenchymal stem cells can be obtained from mammalian (e.g., human) tissue such as bone marrow and trabecular bone. Mesenchymal stem cells can be cultured in vitro. For example, mesenchymal stem cells can be expanded in number in vitro. Mesenchymal stem cells can express or not express a polypeptide marker on the cell surface. For example, mesenchymal stem cells can express CD 105, CD 166, CD29, and CD44 on the cell surface and not express CD 14, CD34, and CD45 on the cell surface.

Any appropriate method can be used to derive differentiated cardioprogenitor cells from stem cells (e.g., mesenchymal stem cells). For example, differentiated cardioprogenitor cells can be derived from mesenchymal stem cells by incubating the mesenchymal stem cells with a composition (e.g., culture media). The composition can be any appropriate composition containing one or more factors. The factors can be any type of factors such as polypeptides, steroids, hormones, and small molecules. Examples of such factors include, without limitation, TGFβ, BMP, FGF2, IGF-I, activin-A, cardiotrophin, α-thrombin, and cardiogenol C. In one embodiment, media containing TGFβ, BMP, cardiotrophin, α-thrombin, and cardiogenol C can be used to obtain differentiated cardioprogenitor cells from stem

cells (e.g., mesenchymal stem cells). In such cases, FGF2, IGF-I, activin-A, or a combination thereof can be added to the medium after an initial culture period (e.g., one or two days) with medium containing TGFβ, BMP, cardiotrophin, α-thrombin, and cardiogenol C. TGFβ can be any polypeptide having TGFβ activity, such as human TGFβ. For example, TGFβ can be recombinant TGFβ or synthetic TGFβ. In one embodiment, TGFβ can be TGFβ-1. Any appropriate concentration of TGFβ can be used. For example, between 1 and 10 ng of TGF-β per mL (e.g., about 2.5 ng of TGFβl per mL) can be used. BMP can be any polypeptide having BMP activity, such as human BMP. For example, BMP can be recombinant BMP or synthetic BMP. In one embodiment, BMP can be BMP4. Any concentration of BMP can be used. For example, between 1 and 20 ng of BMP per mL (e.g., about 5 ng of BMP4 per mL) can be used. FGF2 can be any polypeptide having FGF2 activity, such as human FGF2. For example, FGF2 can be recombinant FGF2 or synthetic FGF2. Any concentration of FGF2 can be used. For example, between 1 and 20 ng of FGF2 per mL (e.g., about 5 ng of FGF2 per mL) can be used. IGF-I can be any polypeptide having IGF-I activity, such as human IGF-I. For example, IGF-I can be recombinant IGF-I or synthetic IGF-I. Any concentration of IGF-I can be used. For example, between 10 and 100 ng of IGF-I per mL (e.g., about 50 ng of IGF-I per mL) can be used. Activin-A can be any polypeptide having activin-A activity, such as human activin-A. For example, activin-A can be recombinant activin-A or synthetic activin-A. Any concentration of activin-A can be used. For example, between 1 and 50 ng of activin-A per mL (e.g., about 10 ng of activin-A per mL) can be used. Cardiotrophin can be any polypeptide having cardiotrophin activity, such as human cardiotrophin- 1. For example, cardiotrophin can be recombinant cardiotrophin or synthetic cardiotrophin. Any concentration of cardiotrophin can be used. For example, between 0.5 and 10 ng of cardiotrophin per mL (e.g., about 1 ng of cardiotrophin- 1 per mL) can be used. α-Thrombin can be any polypeptide having α-thrombin activity, such as human α-thrombin. For example, α-thrombin can be recombinant α-thrombin or synthetic α-thrombin. Any concentration of α-thrombin can be used. For example, between 0.5 and 10 units of α-thrombin per mL (e.g., about 1 unit of α-thrombin per mL) can be used. Any concentration of cardiogenol C or a pharmaceutically acceptable salt

thereof (e.g., cardiogenol C hydrochloride) can be used. For example, between 10 and 1000 nM of cardiogenol C (e.g., about 100 nM of cardiogenol C) can be used.

In some cases, serum-containing or serum- free media supplemented with TGFβ-1 (e.g., 2.5 ng/niL), BMP4 (e.g., 5 ng/niL), FGF2 (e.g., 5 ng/mL), IGF-I (e.g., 50 ng/niL), activin-A (e.g., 10 ng/mL), cardiotrophin (e.g., 1 ng/mL), α-thrombin (e.g., 1 Unit/mL), and cardiogenol C (e.g., 100 nM) can be used to obtain differentiated cardioprogenitor cells from stem cells (e.g., mesenchymal stem cells). In some cases, the media (e.g., serum-containing or serum-free media) can contain platelet lysate (e.g., a human platelet Iy sate). In some cases, the composition used to obtain differentiated cardioprogenitor cells from mesenchymal stem cells can contain additional optional factors such as TNF-α, IL- 6, LIF, VEGF-A, and retinoic acid. TNF-α can be any polypeptide having TNF-α activity, such as human TNF-α. For example, TNF-α can be recombinant TNF-α or synthetic TNF-α. Any concentration of TNF-α can be used. For example, between 5 and 50 ng of TNF-α per mL can be used. IL-6 can be any polypeptide having IL-6 activity, such as human IL-6. For example, IL-6 can be recombinant IL-6 or synthetic IL-6. Any concentration of IL-6 can be used. For example, between 100 and 200 ng of IL-6 per mL can be used. LIF can be any polypeptide having LIF activity, such as human LIF. For example, LIF can be recombinant LIF or synthetic LIF. Any concentration of LIF can be used. For example, between 2.5 and 100 ng of LIF per mL can be used. VEGF-A can be any polypeptide having VEGF-A activity, such as human VEGF-A. For example, VEGF-A can be recombinant VEGF-A or synthetic VEGF-A. Any concentration of VEGF-A can be used. For example, between 5 and 200 ng of VEGF-A per mL can be used. Retinoic acid can be any molecule having retinoic acid activity, such as synthetic retinoic acid, natural retinoic acid, a vitamin A metabolite, a natural derivative of vitamin A, or a synthetic derivative of vitamin A. Any concentration of retinoic acid can be used. For example, between 1 x 10 ^"6 and 2 x 10 ^"6 μM of retinoic acid can be used.

A composition provided herein can contain any combination of factors. For example, a composition provided herein can contain TGFβ-1, BMP4, activin-A, cardiotrophin, α-thrombin, and cardiogenol C. In some cases, a composition provided herein can contain TGFβ-1, BMP4, FGF2, IGF-I, cardiotrophin, α-thrombin, and

cardiogenol C. In some cases, a composition provided herein can contain TGFβ-1, BMP4, FGF2, IGF-I, cardiotrophin, α-thrombin, and cardiogenol C. In some cases, a composition provided herein can lack TNF-α, IL-6, LIF, VEGF-A, retinoic acid, or any combination thereof (e.g., IL-6, LIF, VEGF-A, and retinoic acid; LIF, VEGF-A, and retinoic acid; or TNF-α, IL-6, LIF, and VEGF-A).

A composition provided herein can be prepared using any appropriate method. For example, a composition provided herein can be prepared using commercially available factors. In some cases, a composition provided herein can be prepared to contain cells lysates (e.g., a platelet lysate) or conditioned media from cells such as cardiomyocyte cells or TNF-α-stimulated endodermal cells. For example, a composition provided herein can be prepared using a platelet lysate supplemented with commercially available factors. In some cases, a composition provided herein can be prepared using factors isolated from conditioned medium. In some cases, the factors can be dissolved in media such as cell culture media that does or does not contain serum. Any appropriate method can be used to incubate stem cells (e.g., mesenchymal stem cells) with a composition provided herein to obtain differentiated cardioprogenitor cells having the ability to incorporate into heart tissue as functional cardiomyocytes. For example, mesenchymal stem cells can be incubated with a composition provided herein for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, or 50 days. In some cases, a composition provided herein and used to incubate mesenchymal stem cells can be replaced every day or every 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, or 50 days. In some cases, mesenchymal stem cells can be incubated with a composition provided herein in the presence or absence of serum. Any appropriate cell density can be used when incubating stem cells with a composition provided herein. For example, between about 1000 and 2000 mesenchymal stem cells per cm ² (e.g., between about 1500-2000 cells/cm ² ) can be incubated with a composition provided herein to obtain differentiated cardioprogenitor cells.

Once stem cells (e.g., mesenchymal stem cells) have been incubated with a composition provided herein or otherwise treated with differentiation factors, the state of differentiation can be monitored to determine whether or not the stem cells differentiated

into differentiated cardioprogenitor cells having the ability to incorporate into heart tissue as functional cardiomyocytes. For example, a sample of cells can be collected and assessed using techniques such as Western blotting, fluorescence-activated cell sorting (FACS), immunostaining, laser confocal microscopy, and reverse transcription polymerase chain reaction (RT-PCR) techniques (e.g., quantitative RT-PCR). In some cases, cells found to express an elevated level of MEF2c, MESP-I, Tbx-5, Nkx2.5, GAT A6, or Fog2 polypeptides or mRNA can be selected for administration into a mammal to treat heart tissue. As described herein, differentiated cardioprogenitor cells derived from mesenchymal stem cells cultured with a platelet lysate containing TGFβ-1, BMP4, FGF2, IGF-I, activin-A, cardiotrophin, α-thrombin, and cardiogenol C exhibited a 2 to 4-fold increase in MEF2c mRNA, MESP-I mRNA, Tbx-5 mRNA, GAT A6 mRNA, or Fog2 mRNA levels as compared to the levels observed with pre -treated mesenchymal stem cells. These differentiated cardioprogenitor cells also exhibited the ability to incorporate into heart tissue as functional cardiomyocytes when injected intramyocardially, subcutaneously, or intravascularly with heart pump function improvement directly correlated with structural repair in both ischemic and non-ischemic settings. Functional benefit was documented both echocardiographically in vivo, and histologically on autopsy through staining of human specific proteins. Also as described herein, differentiated cardioprogenitor cells derived from mesenchymal stem cells cultured with serum containing TGFβ-1, BMP4, FGF2, IGF-I, activin-A, cardiotrophin, α-thrombin, and cardiogenol C exhibited a 5 to 10-fold increase in MEF2c mRNA, MESP-I mRNA, and Tbx-5 mRNA levels as compared to the levels observed with pre- treated mesenchymal stem cells. These differentiated cardioprogenitor cells also exhibited the ability to incorporate into heart tissue as functional cardiomyocytes when injected intramyocardially (e.g., through endocardial or epicardial routes), into the coronary arteries, infused in the heart, or administered systemically (e.g., subcutaneously), with heart pump function improvement directly correlated with structural repair in both ischemic and non-ischemic settings. Functional benefit was documented by cardiac ultrasound in vivo, and by microscopic analysis on autopsy through staining of human specific proteins. Thus, release criteria such as elevated

polypeptide or mRNA levels of MEF2c, MESP-I, Tbx-5, GAT A6, Fog2, or combinations thereof can be used to evaluate cells prior to administration into a mammal.

The term "elevated level" as used herein with respect to polypeptide or mRNA levels of MEF2c, MESP-I, Tbx-5, GATA6, or Fog2 within a cell population refers to any level that is greater than a reference level for that polypeptide or mRNA. The term

"reference level" as used herein with respect to polypeptide or mRNA levels of MEF2c, MESP-I, Tbx-5, GAT A6, or Fog2 within a cell population refers to the level typically found in pre-treated cells (e.g., pre-treated mesenchymal stem cells). For example, an MEF2c mRNA reference level, an MESP-I mRNA reference level, a Tbx-5 mRNA reference level, a GAT A6 mRNA reference level, and a Fog2 mRNA reference level can be the average level of MEF2c, MESP-I, Tbx-5, GAT A6, and Fog2 mRNA, respectively, that is present in a random sampling of mesenchymal stem cells not treated with a composition provided herein or otherwise treated with differentiation factors. It will be appreciated that levels from comparable samples are used when determining whether or not a particular level is an elevated level.

Elevated polypeptide or mRNA levels of MEF2c, MESP-I, Tbx-5, GATA6, or Fog2 can be any level provided that the level is greater than a corresponding reference level. For example, an elevated level of Tbx-5 mRNA can be 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more fold greater than the reference level Tbx-5 mRNA observed in untreated mesenchymal stem cells. It is noted that a reference level can be any amount. For example, a reference level for Tbx-5 mRNA can be zero. In this case, any level of Tbx-5 mRNA greater than zero would be an elevated level.

In some cases, release criteria can include microscopic analysis of cells prior to administration into a mammal. Such microscopic analysis can include assessing the cells for transcription factor polypeptides associated with the nucleus. For example, cells appropriate for release into a mammal can be assessed for the presence of Nkx2.5, MEF2c, GAT A4, MESP-I, Tbx-5, or any combination thereof associated with the nucleus before being released into the mammal.

Any appropriate method can be used to provide heart tissue with differentiated cardioprogenitor cells having the ability to incorporate into heart tissue as functional cardiomyocytes. For example, differentiated cardioprogenitor cells can be injected

intramyocardially (e.g., through endocardial or epicardial routes), into the coronary arteries, infused in the heart, or administered systemically (e.g., subcutaneously). Any heart tissue can be provided with differentiated cardioprogenitor cells. For example, mammalian (e.g., human) heart tissue can be provided with differentiated cardioprogenitor cells. In some cases, heart tissue that has suffered from ischemic cardiomyopathy, myocardial infarction, or heart failure can be provided with differentiated cardioprogenitor cells. Any type of differentiated cardioprogenitor cells can be administered to heart tissue. For example, autologous or heterologous differentiated cardioprogenitor cells can be administered to heart tissue. In some cases, stem cells (e.g., mesenchymal stem cells) that were incubated with a composition provided herein can be administered to heart tissue. The stem cells can be incubated with a composition provided herein for any length of time before being administered to heart tissue. For example, the stem cells can be incubated with a composition provided herein for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, or 50 days before being administered to heart tissue. In some cases, stem cells that were incubated with a composition provided herein can be administered to heart tissue together with a composition provided herein. The stem cells can be incubated with a composition provided herein for any length of time before being administered to heart tissue together with a composition provided herein. For example, the stem cells can be incubated with a composition provided herein for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, or 50 days before being administered to heart tissue together with a composition provided herein.

In some cases, differentiated cardioprogenitor cells can be assessed to determine whether or not they meet particular release criteria prior to being administered to a mammal. For example, differentiated cardioprogenitor cells can be assessed using RT- PCR to confirm that the differentiated cardioprogenitor cells express an elevated polypeptide or mRNA level of MEF2c, MESP-I, Tbx-5, GAT A6, Fog2, or combinations thereof before being administered into a mammal.

The invention will be further described in the following examples, which do not limit the scope of the invention described in the claims.

EXAMPLES

Example 1 - Obtaining and Using Differentiated Cardioprogenitor Cells Mesenchymal stem cells were derived from human bone marrow withdrawn from the posterior iliac crest of the pelvic bone of 18- to 45-year-old healthy individuals (Cambrex, East Rutherford, New Jersey). Based on flow cytometry analysis, the mesenchymal stem cells expressed CD 105, CD 166, CD29, and CD44, and did not express CD 14, CD34, and CD45.

Human bone marrow-derived mesenchymal stem cells were cultured in either platelet lysate or serum supplemented with TGFβ-1 (2.5 ng/niL), BMP4 (5 ng/niL), FGF2 (5 ng/mL), IGF-I (50 ng/mL), activin-A (10 ng/mL), cardiotrophin (1 ng/mL), α- thrombin (1 Unit/mL), and cardiogenol C (100 nM). After 4-10 days in the platelet lysate-containing culture at a density of about 1000-2000 cells per cm ² , the cells were found to express 2-4-fold more MEF2c mRNA, MESP-I mRNA, Tbx-5 mRNA, GAT A6 mRNA, or Fog2 mRNA than untreated mesenchymal stem cells. After 5-15 days in the serum-containing culture at a density of about 1000-2000 cells per cm ² , the cells were found to express 5- 10-fold more MEF2c mRNA, MESP-I mRNA, Tbx-5 mRNA, GAT A6 mRNA, or Fog2 mRNA than untreated mesenchymal stem cells. The primer pairs used for the RT-PCR analysis were standard primers obtained commercially from Applied Biosystems. Results demonstrating that the differentiated cardioprogenitor cells have the ability to incorporate into heart tissue as functional cardiomyocytes were obtained both in vivo within the beating heart, and in vitro following autopsy. In vivo, under isoflurane anesthesia, direct myocardial delivery of cardioprogenitor cells into diseased hearts improved cardiac performance as monitored by echocardiography in the short axis with a two-dimensional M-mode probing in the long axis, Doppler pulse wave analysis, and 12- lead electrocardiography. Harvested heart tissue was fixed in 3% paraformaldehyde, sectioned, and subjected to immuno-probing for human cell tracking. New human derived cardiomyocytes and vasculature, with functional improvement and scar resolution, was documented on analysis in mice treated with cardioprogenitor cells fulfilling release criteria (e.g., elevated expression of MEF2c mRNA, MESP-I mRNA,

Tbx-5 mRNA, GATA6 mRNA, or Fog2 mRNA), in contrast to absence of benefit with cells that did not pass the release criteria.

OTHER EMBODIMENTS

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.