Difluoromethylornithine stimulates early cardiac commitment of mesenchymal stem cells in a model of mixed culture with cardiomyocytes

Effect of a dianthin G analogue in the differentiation of rat bone marrow mesenchymal stem cells into cardiomyocytes

Loss of cardiomyocytes due to myocardial infarction results in ventricular remodeling which includes non-contractile scar formation, which can lead to heart failure. Stem cell therapy aims to replace the scar tissue with the functional myocardium. Mesenchymal stem cells (MSCs) are undifferentiated cells capable of self-renewal as well as differentiation into multiple lineages. MSCs can be differentiated into cardiomyocytes by treating them with small molecules and peptides. Here, we report for the first time, the role of a cyclic peptide, an analogue of dianthin G, [Glu²]-dianthin G (1) in the in vitro cardiac differentiation of rat bone marrow MSCs. In this study, [Glu²]-dianthin G (1) was synthesized using solid-phase total synthesis and characterized by NMR spectroscopy. MSCs were treated with two different concentrations (0.025 and 0.05 mM) of the peptide separately for 72 h and then incubated for 15 days to allow the cells to differentiate into cardiomyocytes. Treated cells were analyzed for the expression of cardiac-specific genes and proteins. Results showed significant upregulation of cardiac-specific genes GATA4, cardiac troponin T (cTnT), cardiac troponin I (cTnI), cardiac myosin heavy chain, and connexin 43 in the treated MSCs compared to the untreated control. For cardiac-specific proteins, GATA4, cTnT, and Nkx2.5 were analyzed in the treated cells and were shown to have significant upregulation as compared to the untreated control. In conclusion, this study has demonstrated the cardiac differentiation potential of [Glu²]-dianthin G (1)-treated rat bone marrow MSCs in vitro both at the gene and at the protein levels. Transplantation of pre-differentiated MSCs into the infarcted myocardium may result in the efficient regeneration of cardiac cells and restoration of normal cardiac function.

Caveolin-1 Plays an Important Role in the Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells into Cardiomyocytes

OBJECTIVES

Accumulating evidence has demonstrated that bone marrow-derived mesenchymal stem cells (BMSCs) may transdifferentiate into cardiomyocytes, making BMSCs a promising source of cardiomyocytes for transplantation. However, little is known about the molecular mechanisms underlying myogenic conversion of BMSCs.

METHODS

This study was designed to investigate the functional role of caveolin-1 in the cardiomyocyte differentiation of BMSCs and to explore the potential underlying molecular mechanisms.

RESULTS

BMSC differentiation was induced by treatment with 10 μM 5-azacytidine, and immunofluorescence assay showed that the expression of cardiomyocyte marker cardiac troponin T (cTnT) was significantly increased compared with a control group. Meanwhile, an increased caveolin-1 expression was found during the 5-azacytidine-induced BMSC differentiation. Additionally, the role of caveolin-1 in the differentiation process was then studied by using caveolin-1 siRNAs. We found that silencing caveolin-1 during induction remarkably enhanced the expression of cardiomyocyte marker genes, including cTnT, Nkx2.5 (cardiac-specific transcription factor), α-cardiac actin and α-myosin heavy chain (α-MHC). Moreover, we observed that downregulation of caveolin-1 was accompanied by inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation.

CONCLUSIONS

Taken together, these findings demonstrate that caveolin-1 plays an important role in the differentiation of BMSCs into cardiomyocytes in conjunction with the STAT3 pathway.

Oxytocin improves the expression of cardiac specific markers in porcine bone marrow stem cells differentiation

Bone marrow stem cells (BMSCs) treated with 5-azacytidine possess myogenic differentiation potential. Oxytocin (OT) induces cardiomyogenesis in murine embryonic and cardiac stem cells. We attempted to isolate, characterize, and induce OT-mediated cardiomyogenic differentiation of porcine pBMSCs. Cells were treated as: control, OT, and 5-azacytidine groups. During early passages, transcripts of Oct4, GATA4, OT receptor, and phospholamban were expressed. RT-PCR showed upregulation of GATA4 in OT and 5-azacytidine-induced groups. Immunocytochemistry revealed higher expressions of cardiac troponin T and myosin heavy chain in OT than in 5-azacytidine-induced groups (p < 0.01). Western blot analysis showed upregulation of cardiac troponin I in OT-induced pBMSCs (p < 0.01). We infer pBMSCs should be induced during early passages, when expressing transcription factors related to pluripotency and cardiomyogenesis, as well as OT receptor. The more abundant expression of cardiac specific proteins in OT-treated pBMSCs suggests OT could be a more potent cardiomyogenic inducer of pBMSC.

Matrix composition and mechanics direct proangiogenic signaling from mesenchymal stem cells

The secretion of trophic factors that promote angiogenesis from mesenchymal stem cells (MSCs) is a promising cell-based therapeutic treatment. However, clinical efficacy has proved variable, likely on account of ill-defined cell delivery formulations and the inherent complexity of cellular secretion. Here we show how controlling the mechanical properties and protein composition of the extracellular matrix (ECM) surrounding MSCs can guide proangiogenic signaling. Conditioned media from MSCs adherent to polyacrylamide hydrogel functionalized with fibronectin, collagen I, or laminin was applied to 3D matrigel cultures containing human microvascular endothelial cells (HMVECs). The degree of tubulogenesis in HMVECs is shown to depend on both the substrate rigidity and matrix protein composition. MSCs cultured on fibronectin-modified hydrogels show a stiffness dependence in proangiogenic signaling with maximum influence on tubulogenesis observed from 40 kPa conditioned media, twofold higher than commercially available cocktails of growth factors. Quantitative real-time-polymerase chain reaction reveals stiffness-dependent expression of multiple factors involved in angiogenesis that corroborate the functional tubulogenesis assay. Restricting cell spreading with micropatterned surfaces attenuates the conditioned media effects; however, small-molecule inhibitors of actomyosin contractility do not significantly reduce the functional outcome. This work demonstrates how controlling matrix rigidity and protein composition can influence the secretory profile of MSCs. Model systems that deconstruct the physical and biochemical cues involved in MSC secretion may assist in the design of hydrogel biomaterials for cell-based therapies.

Downregulation of HDAC1 is involved in the cardiomyocyte differentiation from mesenchymal stem cells in a myocardial microenvironment

Under myocardial microenvironment, bone marrow-derived mesenchymal stem cells (MSCs) can transdifferentiate into cardiomyocytes (CMs). However, the role of histone deacetylase 1 (HDAC1) in this directed differentiation process remains unclear. The current study is to determine the acetylation regulatory mechanisms that may be involved in the directed CM differentiation from MSCs. MSCs isolated from male Sprague-Dawley (SD) rats were marked with Ad-EGFP and co-cultured with CMs. Flow cytometry was used to sort EGFP-positive (EGFP+) MSCs from the co-culture system. Then, the expression of cardiac troponin T (cTnT) in these MSCs was detected by immunofluorescence assay. In addition, HDAC1 levels at different co-culture times were measured by quantitative real-time polymerase chain reaction (QT-PCR) and Western blotting. At 4 days after co-culture with CMs, the MSCs began to expression detectable levels of cTnT. The expression of HDAC1 in CMs was much lower than that in MSCs. After co-culture with CMs, the expression of HDAC1 in MSCs was significantly decreased in a time dependent manner. In addition, our recent study has also identified that knockdown of the HDAC1 could promote the directed differentiation of MSCs into CMs. The results suggest that HDAC1 has a negative correlation with cardiac cell differentiation from MSCs under a myocardial microenvironment. HDAC1 might play an important role in the directed differentiation of MSCs into CMs in heart.

Knockdown of the HDAC1 promotes the directed differentiation of bone mesenchymal stem cells into cardiomyocytes

Failure of the directed differentiation of the transplanted stem cells into cardiomyocytes is still a major challenge of cardiac regeneration therapy. Our recent study has demonstrated that the expression of histone deacetylase 1 (HDAC1) is decreased in bone mesenchymal stem cells (BMSCs) during their differentiation into cardiomyocytes. However, the potential roles of HDAC1 in cardiac cell differentiation of BMSCs, as well as the mechanisms involved are still unclear. In current study, the expression of HDAC1 in cultured rat BMSCs is knocked down by lentiviral vectors expressing HDAC1-RNAi. The directed differentiation of BMSCs into cardiomyocytes is evaluated by the expression levels of cardiomyocyte-related genes such as GATA-binding protein 4 (GATA-4), Nirenberg, Kim gene 2 homeobox 5 (Nkx2.5), cardiac troponin T (CTnT), myosin heavy chain (MHC), and connexin-43. Compared with that in control BMSCs, the expression of these cardiomyocyte-related genes is significantly increased in these HDAC1 deficient stem cells. The results suggest that HDAC1 is involved in the cardiomyocyte differentiation of BMSCs. Knockdown of the HDAC1 may promote the directed differentiation of BMSCs into cardiomyocytes.

In vitro protection of adipose tissue-derived mesenchymal stem cells by erythropoietin

Mobilization of stem cells and their differentiation into cardiomyocytes are known to have protective effects after myocardial infarction. The integrity of transplanted mesenchymal stem cells for cardiac regeneration is dependent on cell-cell or cell-matrix interaction, which is adversely affected by reactive oxygen species in an ischemic environment. Treatment with erythropoietin was shown to protect human adipose tissue derived mesenchymal stem cells in an ischemic injury in vitro model. The analyses indicated that expression of erythropoietin receptors played a pivotal role in erythropoietin mediated cell survival. In this study, the anti-apoptotic effect of erythropoietin on stem cells was analyzed in apoptosis-induced human mesenchymal stem cells. Apoptosis was induced in cultured adult human adipose tissue derived mesenchymal stem cells by hydrogen peroxide. A group of cultured cells was also treated with recombinant human erythropoietin in a concentration of 50 ng mL(-1). The degree of apoptosis was analyzed by flow-cytometry and immunohistochemical staining for Caspase 3. The average percentages of apoptotic cells were significantly higher in H2O2-induced stem cells than in cells co-cultured with erythropoietin (63.03 ± 4.96% vs 29 ± 3.41%, p<0.01). We conclude that preconditioning with erythropoietin suppresses apoptosis of mesenchymal stem cells and enhances their survival.

Chromatin remodeling by polyamines and polyamine analogs

Natural polyamines are involved in many molecular processes, including maintenance of DNA structure and RNA processing and translation. Our aim here is to present an overview of the literature concerning the significance of polyamines in the modulation of chromatin arrangement and the transcriptional regulation of gene expression. The pleiotropic picture emerging from the published data highlights that these polycations take part in apparently diverging effects, possibly depending on the heterogeneous experimental settings described, and on a methodological approach aimed at the evaluation of the global levels of the histone chemical modifications. Since the relevant changes observed appear to be rather local and gene specific, investigating histone modifications at the level of specific gene promoters of interest is thus to be recommended for future studies. Furthermore, decoding the multiple regulatory mechanisms by which polyamines exert their influence on chromatin-modifier enzymes will reasonably require focus on selected individual polyamine-regulated genes. The evaluation of the many known chromatin-remodeling enzymes for their individual susceptibility to polyamines or polyamine derivatives will also be helpful: determining how they discriminate between the different enzyme isoforms is expected to be a fruitful line of research for drug discovery, e.g., in cancer prevention and therapy. Indeed, polyamine derivatives acting as epigenetic modulators appear to be molecules with great potential as antitumor drugs. All these novel polyamine-based pharmacologically active molecules are thus promising tools, both as a stand-alone strategy and in combination with other anticancer compounds.

Distinct patterns of histone modifications at cardiac-specific gene promoters between cardiac stem cells and mesenchymal stem cells

Mesenchymal stem cells (MSCs) and cardiac stem cells (CSCs) possess different potential to develop into cardiomyocytes. The mechanism underlying cardiomyogenic capacity of MSCs and CSCs remains elusive. It is well established that histone modifications correlate with gene expression and contribute to cell fate commitment. Here we hypothesize that specific histone modifications accompany cardiac-specific gene expression, thus determining the differentiation capacity of MSCs and CSCs toward heart cells. Our results indicate that, at the promoter regions of cardiac-specific genes (Myh6, Myl2, Actc1, Tnni3, and Tnnt2), the levels of histone acetylation of H3 (acH3) and H4 (acH4), as a mark indicative of gene activation, were higher in CSCs (Sca-1(+)CD29(+)) than MSCs. Additionally, lower binding levels of histone deacetylase (HDAC) 1 and HDAC2 at promoter regions of cardiac-specific genes were noticed in CSCs than MSCs. Treatment with trichostatin A, an HDAC inhibitor, upregulated cardiac-specific gene expression in MSCs. Suppression of HDAC1 or HDAC2 expression by small interfering RNAs led to increased cardiac gene expression and was accompanied by enhanced acH3 and acH4 levels at gene loci. We conclude that greater levels of histone acetylation at cardiac-specific gene loci in CSCs than MSCs reflect a stronger potential for CSCs to develop into cardiomyocytes. These lineage-differential histone modifications are likely due to less HDAC recruitment at cardiac-specific gene promoters in CSCs than MSCs.

microRNA-124 regulates cardiomyocyte differentiation of bone marrow-derived mesenchymal stem cells via targeting STAT3 signaling

Accumulating evidence demonstrated that bone marrow-derived mesenchymal stem cells (BMSCs) may transdifferentiate into cardiomyocytes and replace apoptotic myocardium so as to improve functions of damaged hearts. However, little information is known about molecular mechanisms underlying myogenic conversion of BMSCs. microRNAs as endogenous noncoding small molecules function to inhibit protein translation post-transcriptionally by binding to complementary sequences of targeted mRNAs. Here, we reported that miR-124 was remarkably downregulated during cardiomyocyte differentiation of BMSCs induced by coculture with cardiomyocytes. Forced expression of miR-124 led to a significant downregulation of cardiac-specific markers-ANP, TNT, and α-MHC proteins as well as reduction of cardiac potassium channel currents in cocultured BMSCs. On the contrary, the inhibition of endogenous miR-124 with its antisense oligonucleotide AMO-124 obviously reversed the changes of ANP, TNT, and α-MHC proteins and increased cardiac potassium channel currents. Further study revealed that miR-124 targeted the 3'UTR of STAT3 gene so as to suppress the expression of STAT3 protein but did not affect its mRNA level. STAT3 inhibitors AG490, WP1066, and S3I-201 were shown to attenuate the augmented expression of ANP, TNT, α-MHC, GATA-4 proteins, and mRNAs in cocultured BMSCs with AMO-124 transfection. Moreover, GATA-4 siRNA reduced the expression of ANP, TNT, α-MHC, and GATA-4 proteins but did not impact STAT3 protein in cocultured BMSCs, indicating GATA-4 serves as an effector of STAT3. In summary, we found that miR-124 regulated myogenic differentiation of BMSCs via targeting STAT3 mRNA, which provides new insights into molecular mechanisms of cardiomyogenesis of BMSCs.

Oligoamine analogues in combination with 2-difluoromethylornithine synergistically induce re-expression of aberrantly silenced tumour-suppressor genes

Epigenetic gene silencing is an important mechanism in the initiation and progression of cancer. Abnormal DNA CpG island hypermethylation and histone modifications are involved in aberrant silencing of tumour-suppressor genes. LSD1 (lysine-specific demethylase 1) was the first enzyme identified to specifically demethylate H3K4 (Lys⁴ of histone H3). Methylated H3K4 is an important mark associated with transcriptional activation. The flavin adenine dinucleotide-binding amine oxidase domain of LSD1 is homologous with two polyamine oxidases, SMO (spermine oxidase) and APAO (N¹-acetylpolyamine oxidase). We have demonstrated previously that long-chain polyamine analogues, the oligoamines, are inhibitors of LSD1. In the present paper we report the synergistic effects of specific oligoamines in combination with DFMO (2-difluoromethylornithine), an inhibitor of ornithine decarboxylase, in human colorectal cancer cells. DFMO treatment depletes natural polyamines and increases the uptake of exogenous polyamines. The combination of oligoamines and DFMO results in a synergistic re-expression of aberrantly silenced tumour-suppressor genes, including SFRP2 (secreted frizzled-related protein 2), which encodes a Wnt signalling pathway antagonist and plays an anti-tumorigenic role in colorectal cancer. The treatment-induced re-expression of SFRP2 is associated with increased H3K4me2 (di-methyl H3K4) in the gene promoter. The combination of LSD1-inhibiting oligoamines and DFMO represents a novel approach to epigenetic therapy of cancer.

Trichostatin a promotes cardiomyocyte differentiation of rat mesenchymal stem cells after 5-azacytidine induction or during coculture with neonatal cardiomyocytes via a mechanism independent of histone deacetylase inhibition

This study was to investigate the effect of trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, on cardiac differentiation of bone marrow mesenchymal stem cells (MSCs) in vitro. Rat MSCs were isolated and divided into six groups: 1) control; 2) 5-azacytidine treatment (5-aza, 10 μM); 3) treatment with TSA (100, 300, and 500 nM); 4) treatment with 5-aza followed by incubation with TSA; 5) coculture with neonatal cardiomyocytes (CMs); and 6) treatment with TSA then coculture with CMs. HDAC activity was significantly inhibited in TSA-treated cells with the maximal inhibition after 24 h of exposure to TSA at 300 nM. No changes in HDAC activity were observed in control, 5-aza-treated, or coculture groups. Following 7 days of differentiation, the expression of early cardiac transcription factors GATA-4, NKx2.5, MEF2c, and cardiac troponin T (cTnT) was increased by 6-8 times in the cells in 5-aza-treated, coculture, or TSA-treated groups over control as determined using real-time PCR, immunofluorescence staining, and Western blotting. However, the percent cTnT-positive cells were dramatically different with 0.7% for control, 10% for 5-aza-treated, 25% for coculture, and 4% for TSA-treated group (500 nM). TSA treatment of the cells pretreated with 5-aza or cocultured with CMs dramatically increased the expression of GATA-4, NKx2.5, and MEF2c by 35-50 times over control. The cTnT protein expression was also significantly increased by over threefold by TSA treatment (500 nM) in both 5-aza-treated and coculture group over control. The percent cTnT-positive cells in both 5-aza-pre-treated and coculture groups were significantly increased by TSA treatment after 1 week of differentiation by up to 92.6% (from 10.3% to 19.8%) and 23.9% (from 24.5% to 30.2%), respectively. These data suggested that TSA enhanced the cardiac differentiation of MSCs after 5-aza induction or during coculture with CMs through a mechanism beyond the inhibition of HDAC activity.

Human cardiomyogenesis and the need for systems biology analysis

Cardiovascular disease remains the leading cause of death in the Western world and myocardial infarction is one of the primary facets of this disease. The limited natural self-renewal of cardiac muscle following injury and restricted supply of heart transplants has encouraged researchers to investigate other means to stimulate regeneration of damaged myocardium. The plasticity of stem cells toward multiple lineages offers the potential to repair the heart following injury. Embryonic stem cells have been extensively studied for their ability to differentiate into early cardiomyocytes, however, the pathway has only been partially defined and inadequate efficiency limits their clinical applicability. Some studies have shown cardiomyogenesis from adult mesenchymal stem cells, from both bone marrow and adipose tissue, but their differentiation pathway remains poorly detailed and these results remain controversial. Despite promising results using stem cells in animal models of cardiac injury, the driving mechanisms behind their differentiation down a cardiomyogenic pathway have yet to be determined. Currently, there is a paucity of information regarding cardiomyogenesis on the systemic level. Stem cell differentiation results from multiple signaling parameters operating in a tightly regulated spatiotemporal pattern. Investigating this phenomenon from a systems biology perspective could unveil the abstruse mechanisms controlling cardiomyogenesis that would otherwise require extensive in vitro testing.

Delayed enrichment of mesenchymal cells promotes cardiac lineage and calcium transient development

Bone marrow-derived mesenchymal stem cells (BM-MSCs) can be induced to differentiate into myogenic cells. Despite their potential, previous studies have not been successful in producing a high percentage of cardiac-like cells with a muscle phenotype. We hypothesized that cardiac lineage development in BM-MSC is related to cell passage, culture milieu, and enrichment for specific cell subtypes before and during differentiation. Our study demonstrated that Lin(-) BM-MSC at an intermediate passage (IP; P8-P12) expressed cardiac troponin T (cTnT) after 21 days in culture. Cardiac TnT expression was similar whether IP cells were differentiated in media containing 5-azacytidine+2% FBS (AZA; 14%) or 2% FBS alone (LS; 12%) and both were significantly higher than AZA+5% FBS. This expression was potentiated by first enriching for CD117/Sca-1 cells followed by differentiation (AZA, 39% and LS, 28%). A second sequential enrichment for the dihydropyridine receptor subunit alpha2delta1 (DHPR-alpha2) resulted in cardiac TnT expressed in 54% of cultured cells compared to 28% of cells after CD117/Sca-1(+) enrichment. Cells enriched for CD117/Sca-1 and subjected to differentiation displayed spontaneous intracellular Ca(2+) transients with an increase in transient frequency and a 60% decrease in the transient duration amplitude between days 14 and 29. In conclusion, IP CD117/Sca-1(+) murine BM-MSCs display robust cardiac muscle lineage development that can be induced independent of AZA but is diminished under higher serum concentrations. Furthermore, temporal changes in calcium kinetics commensurate with increased cTnT expression suggest progressive maturation of a cardiac muscle lineage. Enrichment with CD117/Sca-1 to establish lineage commitment followed by DHPR-alpha2 in lineage developing cells may enhance the therapeutic potential of these cells for transplantation.

Adenovirus-mediated hypoxia-inducible factor 1alpha double-mutant promotes differentiation of bone marrow stem cells to cardiomyocytes

The hypoxia-inducible factor 1alpha (HIF-1alpha) regulates transcriptional genes involved in cell proliferation, survival, and differentiation. Under normoxia, HIF-1alpha has a short half-life (t((1/2)) approximately 5 min) and low transcriptional activity. An HIF-1alpha mutant, produced by substitution of alanine (Ala) for proline (Pro) at position 564 and asparagine (Asp) at position 803, can prevent HIF-1alpha hydroxylation and results in a highly active form of HIF-1alpha (HIF-1alpha-Ala564-Ala803). We hypothesized that adenovirus (Ad)-mediated transfer of the active form of HIF-1alpha (pAd-HIF-1alpha-Ala564-Ala803) could effectively occur in bone marrow stem cells (MSCs) and promote MSC differentiation under normoxia. PCR-based site-specific mutagenesis was used to construct the Ad vector expressing HIF-1alpha-Ala564-Ala803. RT-PCR and immunostaining were used to study whether pAd-HIF-1alpha-Ala564-Ala803 affected MSC differentiation to cardiomyocyte (CMC). pAd-HIF-1alpha-Ala564-Ala803 exhibited higher transcriptional activity and stable HIF-1alpha protein expression. Under normoxia, an MSC-CMC co-culture treated with pAd-HIF1a-Ala564-Ala803 augmented TGF-beta(1), Smad4, NKx2.5, and GATA4 expression. Higher expression of cTnT and alpha-actinin was observed by immunostaining in MSCs, compared with the control and contrast groups. Adenovirus-mediated hypoxia-inducible factor 1alpha double-mutant, pAd-HIF-1alpha-Ala564-Ala803, can stably express HIF-1alpha and promote its downstream genes and MSC differentiation to CMC in the MSC-CMC co-culture system under normoxia.

Timing of induction of cardiomyocyte differentiation for in vitro cultured mesenchymal stem cells: a perspective for emergencies

Mesenchymal stem cells (MSCs) have the capacity to differentiate into osteoblasts, chondrocytes, adipocytes, myocytes, and cardiomyocytes. Several established methods are presently available for in vitro isolation of MSCs from bone marrow. However, the duration necessary to culture them can be a major handicap to cell-based therapies needed for such urgent cardiovascular conditions as acute myocardial infarction and acute hindlimb ischemia. The best timing of cardiomyocyte differentiation induction after MCS isolation and expansion is still an unresolved issue. Our goal was to investigate the possibility of obtaining functional cardiomyocytes from rat MSC within a shorter time period. We examined MSCs' colony-forming capacity, CD90 and CD34 immunoreactivity during the 14 days of culturing. Cardiomyocyte differentiation was induced by 5-azacytidine. Immunohistochemic staining, together with intracellular Ca2+ measurement experiments, revealed that MSCs do not differentiate into any specific cell lineage but show the characteristics of MSCs on both the 9th and 14th days of the culture. To check the potential for differentiation into cardiomyocytes, experiments with caffeine application and depolarization with KCl were performed. The cells possessed some of the specific biochemical features of contracting cells, with slightly higher capacities on the 14th day. Cells from 9th and 14th days of the culture that were treated with 5-azacytidine had a higher expression of cardiac-specific markers such as troponin I, alpha-sarcomeric actin, and MEF2D compared with the control groups. This study illustrates that it is possible to get functional cardiomyocytes from in vitro MSC culture in a shorter time period than previously achieved. This reduction in time may provide emergency cases with access to cell-based therapies that may have previously been unavailable.