Marrow stromal cells for cellular cardiomyoplasty: feasibility and potential clinical advantages

Ectopic CD4+ T cells in choroid plexus mediate neuropsychiatric lupus symptoms in mice via interferon-γ induced microglia activation

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a disabling and potentially life-threatening complication of SLE. This study aims to investigate whether ectopic CD4+ T cells in the choroid plexus mediate NPSLE in mice. Intracerebroventricular (ICV) injection of anti-CD4 antibody effectively depleted CP-resident CD4+ T cells and alleviated NPSLE-like symptoms in MRL/lpr mice. Following ICV injection, the majority of isolated lupus CD4+ T cells from donor MRL/lpr mice predominantly stayed in the CP for at least 28 days in recipient C57BL/6 mice, while nearly all isolated CD4+ T cells from MRL/MpJ mice disappeared within 7 days. ICV injection of lupus CD4+ T cells resulted in NPSLE-like symptoms, including impaired behavioral performances, increased microglial activation, and abnormal microstructure changes. Flow cytometry analysis revealed that the majority of isolated lupus CD4+ T cells were positive for IFN-γ. Neutralizing intracerebral IFN-γ alleviated NPSLE-like symptoms in MRL/lpr mice. Moreover, ICV injection of anti-IFN-γ antibody or microglial depletion by PLX3397 benefited most NPSLE-like symptoms in lupus CD4+ T-treated mice, while ICV injection of IFN-γ mimicked most NPSLE-like symptoms. In conclusion, CP-resident lupus CD4+ T cells contribute to NPSLE-like symptoms in mice via Interferon-γ induced microglia activation. Depleting CP-resident lupus CD4+ T cells, interferon-γ, or activated microglia may be potential therapeutic targets for NPSLE.

The adipose-derived mesenchymal stem cell secretome promotes hepatic regeneration in miniature pigs after liver ischaemia-reperfusion combined with partial resection

Background

Hepatic ischaemia-reperfusion injury (HIRI) is inevitable in complicated liver surgery and is a major factor leading to postoperative complications and liver dysfunction. Studies have shown that the paracrine mechanisms of stem cell may be essential to tissue repair and functional improvement after transplantation. However, the role of the adipose-derived mesenchymal stem cell secretome (ASC-secretome) in liver regeneration in large animals remains to be determined.

Methods

Twenty-four miniature pigs were subjected to laparoscopic liver ischaemia-reperfusion combined with partial hepatectomy and divided into the following four groups: the saline group, the DMEM group, the ASC group and the ASC-secretome group. Serum and liver tissue samples were collected before the operation and at 1, 3 and 7 days after the operation, and changes in tissue pathology, serum inflammation, liver function, angiogenesis-related factors and liver tissue regeneration-related genes and proteins were evaluated.

Results

Detailed histological analysis showed that ASCs and the ASC-secretome changed pathological damage to liver tissue after liver ischaemia-reperfusion combined with partial hepatectomy (1 and 3 days: p < 0.01). Compared with the saline and DMEM control groups, the ASC-secretome group had significantly reduced expression levels of ALP (1 and 3 days: p < 0.05), ALT (1 day: p < 0.01; 3 days: p < 0.05) and AST (1 and 3 days: p < 0.01), which promoted the recovery of liver function. Moreover, detection of the expression levels of TNF-α and IL-1β (1 day: p < 0.01; 3 days: p < 0.05), IL-6 (1 and 3 days: p < 0.05) and IL-10 (1 and 3 days: p < 0.01) in serum confirmed that the ASC-secretome had obvious anti-inflammatory effects. In addition, the ASC-secretome increased the expression levels of ANG-1 (3 days: p < 0.01), ANG-2 (3 and 7 days: p < 0.01) and VEGF (1 and 7 days: p < 0.05; 3 days: p < 0.01) and promoted angiogenesis during liver regeneration. Moreover, it promoted the mRNA expression of HGF and Cyclin D1 (1 and 3 days: p < 0.01); increased the levels of p-STAT3 (1 and 3 days: p < 0.01), PCNA and Ki67 (1 and 3 days: p < 0.01; 7 days: p < 0.05); inhibited the negative feedback of SOCS3 (1 and 3 days: p < 0.01); and decreased the mRNA expression of TGF-β (3 days: p < 0.01). The cytokines and growth factors detected in the ASC-secretome included TNF-α, IL-6, IL-1β, ANG-1, ANG-2, VEGF and b-FGF.

Conclusion

The ASC-secretome alleviates the inflammatory response induced by ischaemia-reperfusion combined with partial hepatectomy in miniature pigs and promotes liver regeneration.

Acute Myocardial Infarction Reduces Respiration in Rat Cardiac Fibers, despite Adipose Tissue Mesenchymal Stromal Cell Transplant

Adipose-derived mesenchymal stromal cell (AD-MSC) administration improves cardiac function after acute myocardial infarction (AMI). Although the mechanisms underlying this effect remain to be elucidated, the reversal of the mitochondrial dysfunction may be associated with AMI recovery. Here, we analyzed the alterations in the respiratory capacity of cardiomyocytes in the infarcted zone (IZ) and the border zone (BZ) and evaluated if mitochondrial function improved in cardiomyocytes after AD-MSC transplantation. Female rats were subjected to AMI by permanent left anterior descending coronary (LAD) ligation and were then treated with AD-MSCs or PBS in the border zone (BZ). Cardiac fibers were analyzed 24 hours (necrotic phase) and 8 days (fibrotic phase) after AMI for mitochondrial respiration, citrate synthase (CS) activity, F₀F₁-ATPase activity, and transmission electron microscopy (TEM). High-resolution respirometry of permeabilized cardiac fibers showed that AMI reduced numerous mitochondrial respiration parameters in cardiac tissue, including phosphorylating and nonphosphorylating conditions, respiration coupled to ATP synthesis, and maximal respiratory capacity. CS decreased in IZ and BZ at the necrotic phase, whereas it recovered in BZ and continued to drop in IZ over time when compared to Sham. Exogenous cytochrome c doubled respiration at the necrotic phase in IZ. F₀F₁-ATPase activity decreased in the BZ and, to more extent, in IZ in both phases. Transmission electron microscopy showed disorganized mitochondrial cristae structure, which was more accentuated in IZ but also important in BZ. All these alterations in mitochondrial respiration were still present in the group treated with AD-MSC. In conclusion, AMI led to mitochondrial dysfunction with oxidative phosphorylation disorders, and AD-MSC improved CS temporarily but was not able to avoid alterations in mitochondria function over time.

Purified Human Bone Marrow Multipotent Mesenchymal Stem Cells Regenerate Infarcted Myocardium in Experimental Rats

Recent findings suggest the feasibility of cardiac repair by transplantation of bone marrow mesenchymal stem cell (MSCs). However, it remains controversial regarding which cell type is the best source for transplanting into the ischemic heart because of lack of well-defined cell markers. In this study, we investigated the in vitro and in vivo effects of the novel multipotent marrow mesenchymal stem cells (MMSCs) from human bone marrow. Pluripotent markers (Oct4, Bmi1, and Abcg2) and vascular endothelial growth factor (VEGF) were detected by RT-PCR and immunofluorescence in MMSCs. Myocardial differentiation was induced in the expanded MMSC cultures by treatment with 5-azacyline. Expressions of VEGF in the animals transplanted with MMSCs were markedly increased in comparison with the animals injected with fibroblasts or saline at both mRNA and protein levels. VEGF expression was observed in both transplanted MMSCs and recipient cardiomyocytes by immunofluorescence. Confocal immunofluorescence microscopy revealed the specific markers for cardiomyocytes and endothelial cells in transplanted MMSCs 14 days after transplantation. Vessel count was increased and left ventricular function improved post-MMSC transplantation. These results indicate that transplantation of purified MMSCs from human bone marrow upregulated VEGF expression, enhanced angiogenesis, and improved the functional recovery following myocardial infarction in rats.

Stem Cell Therapy for Ischemic Heart Disease: Beginning or End of the Road?

Despite improvements in emergency treatment, myocardial infarction is often the beginning of a downward spiral leading to congestive heart failure. Other than heart transplantation, current therapeutic means aim at enabling the organism to survive with a heart that is working at a fraction of its original capacity. It is therefore no surprise that cardiac stem cell therapy has raised many hopes. However, neither the ideal source and type of stem cell nor the critical cell number and mode of application have been defined so far. Early reports on myocardial repair by adult bone marrow stem cells from rodent models promoted an unparalleled boost of clinical and experimental cell therapy studies. The phenomenon of stem/progenitor cell-induced angiogenesis in ischemic myocardium has ever since been reproduced by numerous groups in a variety of small and large animal models. Myogenesis, however, is an altogether different matter. Many of the initial clinical studies were fueled by the suggestion that early hematopoietic stem cells have a plasticity high enough to enable cross-lineage differentiation into cells of cardiomyocyte phenotype, but the initial enthusiasm has largely faded. The myogenic potential of stroma cell-derived mesenchymal stem cells is much better documented in animal models, but transfer to the clinical setting faces a variety of obstacles. In clinical pilot trials, we and others have demonstrated the feasibility and safety of administering progenitor cells derived from autologous bone marrow to the myocardium of patients with ischemic heart disease. Clinical efficacy data are still rare, but the few controlled trials that have been completed uniformly show a tendency towards better heart function in cell-treated patients. This review is an attempt to describe the scientific basis for cardiac cell therapy from the point of view of the clinician, focusing on problems that arise with beginning translation into the clinical setting.

Tissue Engineering Strategies for Myocardial Regeneration: Acellular Versus Cellular Scaffolds?

Heart disease remains one of the leading causes of death in industrialized nations with myocardial infarction (MI) contributing to at least one fifth of the reported deaths. The hypoxic environment eventually leads to cellular death and scar tissue formation. The scar tissue that forms is not mechanically functional and often leads to myocardial remodeling and eventual heart failure. Tissue engineering and regenerative medicine principles provide an alternative approach to restoring myocardial function by designing constructs that will restore the mechanical function of the heart. In this review, we will describe the cellular events that take place after an MI and describe current treatments. We will also describe how biomaterials, alone or in combination with a cellular component, have been used to engineer suitable myocardium replacement constructs and how new advanced culture systems will be required to achieve clinical success.

Mesenchymal Stem Cells and the Treatment of Cardiac Disease

The ischemia-induced death of cardiomyocytes results in scar formation and reduced contractility of the ventricle. Several preclinical and clinical studies have supported the notion that cell therapy may be used for cardiac regeneration. Most attempts for cardiomyoplasty have considered the bone marrow as the source of the “repair stem cell(s),” assuming that the hematopoietic stem cell can do the work. However, bone marrow is also the residence of other progenitor cells, including mesenchymal stem cells (MSCs). Since 1995 it has been known that under in vitro conditions, MSCs differentiate into cells exhibiting features of cardiomyocytes. This pioneer work was followed by many preclinical studies that revealed that ex vivo expanded, bone marrow–derived MSCs may represent another option for cardiac regeneration. In this work, we review evidence and new prospects that support the use of MSCs in cardiomyoplasty.

Stem cell-derived cell-sheets for connective tissue engineering

Cell-sheet technology involves the recovery of cells with its secreted ECM and cell-cell junctions intact, and thereby harvesting them in a single contiguous layer. Temperature changes coupled with a thermoresponsive polymer grafted culture plate surface are typically used to induce detachment of this cell-matrix layer by controlling the hydrophobicity and hydrophilicity properties of the culture surface. This review article details the genesis and development of this technique as a critical tissue-engineering tool, with a comprehensive discussion on connective tissue applications. This includes applications in the myocardial, vascular, cartilage, bone, tendon/ligament, and periodontal areas among others discussed. In particular, further focus will be given to the use of stem cells-derived cell-sheets, such as those involving bone marrow-derived and adipose tissue-derived mesenchymal stem cells. In addition, some of the associated challenges faced by approaches using stem cells-derived cell-sheets will also be discussed. Finally, recent advances pertaining to technologies forming, detaching, and manipulating cell-sheets will be covered in view of the potential impact they will have on shaping the way cell-sheet technology will be utilized in the future as a tissue-engineering technique.

Low-Level Laser Irradiation Precondition for Cardiac Regenerative Therapy

OBJECTIVE

The purpose of this article was to review the molecular mechanisms of low-level laser irradiation (LLLI) preconditioning for heart cell therapy.

BACKGROUND DATA

Stem cell transplantation appears to offer a better alternative to cardiac regenerative therapy. Previous studies have confirmed that the application of LLLI plays a positive role in regulating stem cell proliferation and in remodeling the hostile milieu of infarcted myocardium. Greater understanding of LLLI's underlying mechanisms would be helpful in translating cell transplantation therapy into the clinic.

METHODS

Studies investigating LLLI preconditioning for cardiac regenerative therapy published up to 2015 were retrieved from library sources and Pubmed databases.

RESULTS

LLLI preconditioning stimulates proliferation and differentiation of stem cells through activation of cell proliferation signaling pathways and alteration of microRNA expression. It also could stimulate paracrine secretion of stem cells and alter cardiac cytokine expression in infarcted myocardium.

CONCLUSIONS

LLLI preconditioning provides a promising approach to maximize the efficacy of cardiac cell-based therapy. Although many studies have reported possible molecular mechanisms involved in LLLI preconditioning, the exact mechanisms are still not clearly understood.

Rebuilding the Damaged Heart: Mesenchymal Stem Cells, Cell-Based Therapy, and Engineered Heart Tissue

Mesenchymal stem cells (MSCs) are broadly distributed cells that retain postnatal capacity for self-renewal and multilineage differentiation. MSCs evade immune detection, secrete an array of anti-inflammatory and anti-fibrotic mediators, and very importantly activate resident precursors. These properties form the basis for the strategy of clinical application of cell-based therapeutics for inflammatory and fibrotic conditions. In cardiovascular medicine, administration of autologous or allogeneic MSCs in patients with ischemic and nonischemic cardiomyopathy holds significant promise. Numerous preclinical studies of ischemic and nonischemic cardiomyopathy employing MSC-based therapy have demonstrated that the properties of reducing fibrosis, stimulating angiogenesis, and cardiomyogenesis have led to improvements in the structure and function of remodeled ventricles. Further attempts have been made to augment MSCs' effects through genetic modification and cell preconditioning. Progression of MSC therapy to early clinical trials has supported their role in improving cardiac structure and function, functional capacity, and patient quality of life. Emerging data have supported larger clinical trials that have been either completed or are currently underway. Mechanistically, MSC therapy is thought to benefit the heart by stimulating innate anti-fibrotic and regenerative responses. The mechanisms of action involve paracrine signaling, cell-cell interactions, and fusion with resident cells. Trans-differentiation of MSCs to bona fide cardiomyocytes and coronary vessels is also thought to occur, although at a nonphysiological level. Recently, MSC-based tissue engineering for cardiovascular disease has been examined with quite encouraging results. This review discusses MSCs from their basic biological characteristics to their role as a promising therapeutic strategy for clinical cardiovascular disease.

Effects of Intracoronary Administration of Autologous Adipose Tissue-Derived Stem Cells on Acute Myocardial Infarction in a Porcine Model

PURPOSE

Adipose-derived stem cells (ADSCs) are known to be potentially effective in regeneration of damaged tissue. We aimed to assess the effectiveness of intracoronary administration of ADSCs in reducing the infarction area and improving function after acute transmural myocardial infarction (MI) in a porcine model.

MATERIALS AND METHODS

ADSCs were obtained from each pig's abdominal subcutaneous fat tissue by simple liposuction. After 3 passages of 14-days culture, 2 million ADSCs were injected into the coronary artery 30 min after acute transmural MI. At baseline and 4 weeks after the ADSC injection, 99mTc methoxyisobutylisonitrile-single photon emission computed tomography (MIBISPECT) was performed to evaluate the left ventricular volume, left ventricular ejection fraction (LVEF; %), and perfusion defects as well as the myocardial salvage (%) and salvage index. At 4 weeks, each pig was sacrificed, and the heart was extracted and dissected. Gross and microscopic analyses with specific immunohistochemistry staining were then performed.

RESULTS

Analysis showed improvement in the perfusion defect, but not in the LVEF in the ADSC group (n=14), compared with the control group (n=14) (perfusion defect, -13.0±10.0 vs. -2.6±12.0, p=0.019; LVEF, -8.0±15.4 vs. -15.9±14.8, p=0.181). There was a tendency of reducing left ventricular volume in ADSC group. The ADSCs identified by stromal cell-derived factor-1 (SDF-1) staining were well co-localized by von Willebrand factor and Troponin T staining.

CONCLUSION

Intracoronary injection of cultured ADSCs improved myocardial perfusion in this porcine acute transmural MI model.

Mesenchymal Stem Cells for Cardiac Regenerative Therapy: Optimization of Cell Differentiation Strategy

With the high mortality rate, coronary heart disease (CHD) has currently become a major life-threatening disease. The main pathological change of myocardial infarction (MI) is the induction of myocardial necrosis in infarction area which finally causes heart failure. Conventional treatments cannot regenerate the functional cell efficiently. Recent researches suggest that mesenchymal stem cells (MSCs) are able to differentiate into multiple lineages, including cardiomyocyte-like cells in vitro and in vivo, and they have been used for the treatment of MI to repair the injured myocardium and improve cardiac function. In this review, we will focus on the recent progress on MSCs derived cardiomyocytes for cardiac regeneration after MI.

Maintenance of HL-1 cardiomyocyte functional activity in PEGylated fibrin gels

Successful cellular cardiomyoplasty is dependent on biocompatible materials that can retain the cells in the myocardium in order to promote host tissue repair following myocardial infarction. A variety of methods have been explored for incorporating a cell-seeded matrix into the heart, the most popular options being direct application of an injectable system or surgical implantation of a patch. Fibrin-based gels are suitable for either of these approaches, as they are biocompatible and have mechanical properties that can be tailored by adjusting the initial fibrinogen concentration. We have previously demonstrated that conjugating amine-reactive homo-bifunctional polyethylene glycol (PEG) to the fibrinogen prior to crosslinking with thrombin can increase stability both in vivo and in vitro. Similarly, when mesenchymal stem cells are combined with PEGylated fibrin and injected into the myocardium, cell retention can be significantly increased and scar tissue reduced following myocardial infarction. We hypothesized that this gel system could similarly promote cardiomyocyte viability and function in vitro, and that optimizing the mechanical properties of the hydrogel would enhance contractility. In this study, we cultured HL-1 cardiomyocytes either on top of plated PEGylated fibrin (2D) or embedded in 3D gels and evaluated cardiomyocyte function by assessing the expression of cardiomyocyte specific markers, sarcomeric α-actin, and connexin 43, as well as contractile activity. We observed that the culture method can drastically affect the functional phenotype of HL-1 cardiomyocytes, and we present data suggesting the potential use of PEGylated fibrin gel layers to prepare a sheet-like construct for myocardial regeneration.

Mesenchymal stem cell insights: prospects in cardiovascular therapy

Ischemic heart damage usually triggers cardiomyopathological remodeling and fibrosis, thus promoting the development of heart functional failure. Mesenchymal stem cells (MSCs) are a heterogeneous group of cells in culture, with multipotent and hypoimmunogenic characters to aid tissue repair and avoid immune responses, respectively. Numerous experimental findings have proven the feasibility, safety, and efficiency of MSC therapy for cardiac regeneration. Despite that the exact mechanism remains unclear, the therapeutic ability of MSCs to treat ischemia heart diseases has been tested in phase I/II clinical trials. Based on encouraging preliminary findings, MSCs might become a potentially efficacious tool in the therapeutic options available to treat ischemic and nonischemic cardiovascular disorders. The molecular mechanism behind the efficacy of MSCs on promoting engraftment and accelerating the speed of heart functional recovery is still waiting for clarification. It is hypothesized that cardiomyocyte regeneration, paracrine mechanisms for cardiac repair, optimization of the niche for cell survival, and cardiac remodeling by inflammatory control are involved in the interaction between MSCs and the damaged myocardial environment. This review focuses on recent experimental and clinical findings related to cellular cardiomyoplasticity. We focus on MSCs, highlighting their roles in cardiac tissue repair, transdifferentiation, the MSC niche in myocardial tissues, discuss their therapeutic efficacy that has been tested for cardiac therapy, and the current bottleneck of MSC-based cardiac therapies.

Improvement of cardiac function by placenta-derived mesenchymal stem cells does not require permanent engraftment and is independent of the insulin signaling pathway

INTRODUCTION

The objective of this work was to evaluate the efficacy of placenta-derived mesenchymal stem cell (MSC) therapy in a mouse model of myocardial infarction (MI). Since MSCs can be obtained from two different regions of the human term placenta (chorionic plate or villi), cells obtained from both these regions were compared so that the best candidate for cell therapy could be selected.

METHODS

For the in vitro studies, chorionic plate MSCs (cp-MSCs) and chorionic villi MSCs (cv-MSCs) were extensively characterized for their genetic stability, clonogenic and differentiation potential, gene expression, and immunophenotype. For the in vivo studies, C57Bl/6 mice were submitted to MI and, after 21 days, received weekly intramyocardial injections of cp-MSCs for 3 weeks. Cells were also stably transduced with a viral construct expressing luciferase, under the control of the murine stem cell virus (MSCV) promoter, and were used in a bioluminescence assay. The expression of genes associated with the insulin signaling pathway was analyzed in the cardiac tissue from cp-MSCs and placebo groups.

RESULTS

Morphology, differentiation, immunophenotype, and proliferation were quite similar between these cells. However, cp-MSCs had a greater clonogenic potential and higher expression of genes related to cell cycle progression and genome stability. Therefore, we considered that the chorionic plate was preferable to the chorionic villi for the isolation of MSCs. Sixty days after MI, cell-treated mice had a significant increase in ejection fraction and a reduction in end-systolic volume. This improvement was not caused by a reduction in infarct size. In addition, tracking of cp-MSCs transduced with luciferase revealed that cells remained in the heart for 4 days after the first injection but that the survival period was reduced after the second and third injections. Quantitative reverse transcription-polymerase chain reaction revealed similar expression of genes involved in the insulin signaling pathway when comparing cell-treated and placebo groups.

CONCLUSIONS

Improvement of cardiac function by cp-MSCs did not require permanent engraftment and was not mediated by the insulin signaling pathway.

Cellular extracts from post-mortem human cardiac tissue direct cardiomyogenic differentiation of human adipose tissue-derived stem cells

BACKGROUND AIMS

Human adipose tissue-derived stem cells (hASCs) can be easily (and inexpensively) expanded in culture, and their high plasticity allows their conversion to different cell types. We study the potential capacity of postmortem cardiac tissue to direct cardiac differentiation of hASCs in vitro.

METHODS

Cardiac tissue collected from autopsies was used to obtain cell extracts and conditioned medium, and both approaches were tested for cardiac induction.

RESULTS

Gene expression analyses proved that post-mortem human cardiac tissue maintains genetic integrity. hASCs exposed to the cell extracts or conditioned medium for 2 weeks achieved the appearance of myotube-like structures and were positive for cardiac markers such as sarcomeric α-actinin, cardiac troponin I and T and desmin as proved by immunofluorescence. In addition, differentiated cells showed increased expression of cardiomyocyte-related genes analyzed by reverse transcriptase polymerase chain reaction (GATA-4, myocyte-enhancer factor-2c, α-cardiac actin and cardiac troponin I).

CONCLUSIONS

For the first time, post-mortem human cardiac tissue was used to induce hASC differentiation into myocardial-like cells. The methodology described here would serve as a useful model to obtain cardiomyocyte-like cells in vitro.

Buckled structures and 5-azacytidine enhance cardiogenic differentiation of adipose-derived stem cells

Aim: Myocardial infarction is caused after impairment of heart wall muscle following an immense cell loss and also when the myocardial tissue is lacking the inherent capacity to regenerate for normal functioning of myocardium. An immediate challenge in cardiac regeneration is to devise a strategy that leads to a reproducible degree of cardiac differentiation. We have speculated that ex vivo pretreatment of adipose-derived stem cells (ADSCs) using 5-azacytidine and a suitable patterned nanofibrous construct could lead to cardiomyogenic differentiation and results in superior biological and functional effects on cardiac regeneration of infarcted myocardium. Materials & methods: Polyglycerol sebacate/gelatin fibers were fabricated by core/shell electrospinning with polyglycerol sebacate as the core material and gelatin as the shell material. Patterning of the core/shell fibers to form orthogonal and looped buckled nanostructures was achieved. Results: Results demonstrated that the buckled fibers showing an orthogonal orientation and looped pattern had a Young’s modulus of approximately 3.59 ± 1.58 MPa and 2.07 ± 0.44 MPa, respectively, which was comparable to that of native myocardium. The ADSCs cultured on these scaffolds demonstrated greater expression of the cardiac-specific marker proteins actinin, troponin and connexin 43, as well as characteristic multinucleation as shown by immunocytochemical and morphological analysis, indicating complete cardiogenic differentiation of ADSCs. Conclusion: In the natural milieu, cardiomyogenic differentiation probably involves multiple signaling pathways and we have postulated that a buckled structure combination of chemical treatment and environment-driven strategy induces cardiogenic differentiation of ADSCs. The combination of patterned buckled fibrous structures with stem cell biology may prove to be a productive device for myocardial infarction.

Original submitted 8 March 2012; Revised submitted 23 November 2012

Evaluation of metabolomic changes as a biomarker of chondrogenic differentiation in 3D-cultured human mesenchymal stem cells using proton (1H) nuclear magnetic resonance spectroscopy

PURPOSE

The purpose of this study was to evaluate the metabolomic changes in 3D-cultured human mesenchymal stem cells (hMSCs) in alginate beads, so as to identify biomarkers during chondrogenesis using (1)H nuclear magnetic resonance (NMR) spectroscopy.

MATERIALS AND METHODS

hMSCs (2×10(6) cells/mL) were seeded into alginate beads, and chondrogenesis was allowed to progress for 15 days. NMR spectra of the chondrogenic hMSCs were obtained at 4, 7, 11, and 15 days using a 14.1-T (600-MHz) NMR with the water suppression sequence, zgpr. Real-Time polymerase chain reaction (PCR) was performed to confirm that that the hMSCs differentiated into chondrocytes and to analyze the metabolomic changes indicated by the NMR spectra.

RESULTS

During chondrogenesis, changes were detected in several metabolomes as hMSC chondrogenesis biomarkers, e.g., fatty acids, alanine, glutamate, and phosphocholine. The metabolomic changes were compared with the Real-Time PCR results, and significant differences were determined using statistical analysis. We found that changes in metabolomes were closely related to biological reactions that occurred during the chondrogenesis of hMSCs.

CONCLUSIONS

In this study, we confirm that metabolomic changes detected by (1)H-NMR spectroscopy during chondrogenic differentiation of 3D-cultured hMSCs in alginate beads can be considered as biomarkers of stem cell differentiation.

Hepatocyte growth factor gene-modified bone marrow-derived mesenchymal stem cells transplantation promotes angiogenesis in a rat model of hindlimb ischemia

Angiogenic gene therapy and cell-based therapy for peripheral arterial disease(PAD) have been studied intensively currently. This study aimed to investigate whether combining mesenchymal stem cells(MSCs) transplantation with ex vivo human hepatocyte growth factor(HGF) gene transfer was more therapeutically efficient than the MSCs therapy alone in a rat model of hindlimb ischemia. One week after establishing hindlimb ischemia models, Sprague-Dawley(SD) rats were randomized to receive HGF gene-modified MSCs transplantation(HGF-MSC group), untreated MSCs transplantation (MSC group), or PBS injection(PBS group), respectively. Three weeks after injection, angiogenesis was significantly induced by both MSCs and HGF-MSCs transplantation, and capillary density was the highest in the HGF-MSC group. The number of transplanted cell-derived endothelial cells was greater in HGF-MSC group than in MSC group after one week treatment. The expression of angiogenic cytokines such as HGF and VEGF in local ischemic muscles was more abundant in HGF-MSC group than in the other two groups. In vitro, the conditioned media obtained from HGF-MSCs cultures exerted proproliferative and promigratory effects on endothelial cells. It is concluded that HGF gene-modified MSCs transplantation therapy may induce more potent angiogenesis than the MSCs therapy alone. Engraftment of MSCs combined with angiogenic gene delivery may be a promising therapeutic strategy for the treatment of severe PAD.

Inhibition of apoptosis by knockdown of caspase-3 with siRNA in rat bone marrow mesenchymal stem cells

Transplantation of bone marrow mesenchymal stem cells is a promising new strategy for the repair of infarcted cardiac tissue. However, the majority of transplanted bone marrow mesenchymal stem cells (BMSCs) die soon after transplantation, due in part to oxidative stress in the ischemic region. Oxidative stress is known to induce apoptosis through the activation of caspase-3. The aim of this study is to determine whether small interfering RNA targeting caspase-3 can inhibit the apoptosis of rat BMSCs in vitro. Caspase-3 siRNA expression vectors were prepared and transfected into rat BMSCs in the presence of liposomes. Western blot assay and real-time polymerase chain reaction (RT-PCR) were performed to detect caspase-3 expression. A retrovirus packaging system was employed to package 293FT cells producing caspase-3 siRNA virus, which were transfected into rat BMSCs. Those stably expressing caspase-3 siRNA were screened by Western blot assay and RT-PCR to determine caspase-3 expression levels. Stable transfection of caspase-3 siRNA significantly decreased caspase-3 protein (0.26 ± 0.001 vs. 0.42 ± 0.004, P < 0.05) and mRNA expression (0.19 ± 0.002 vs. 1, P < 0.05) in BMSCs compared to non-transfected BMSCs. Cells were incubated in H2O2 to induce apoptosis, which was detected by TUNEL staining, and BMSC morphology was not altered by either transient or stable transfection of caspase-3 siRNA. H2O2-induced apoptosis of BMSCs stably transfected with caspase-3 siRNA was dramatically reduced compared to that of normal BMSCs (11.0 ± 3.2 vs. 25.8 ± 4.2, P < 0.05). Caspase-3 knockdown BMSCs are thus more resistant to apoptosis than normal BMSCs, potentially increasing their survival rates under conditions that cause oxidative stress.

Muscle-derived stem cell sheets support pump function and prevent cardiac arrhythmias in a model of chronic myocardial infarction

Direct intracardiac cell injection for heart repair is hindered by numerous limitations including: cell death, poor spreading of the injected cells, arrhythmia, needle injury, etc. Tissue-engineered cell sheet implantation has the potential to overcome some of these limitations. We evaluated whether the transplantation of a muscle-derived stem cell (MDSC) sheet could improve the regenerative capacity of MDSCs in a chronic model of myocardial infarction. MDSC sheet-implanted mice displayed a reduction in left ventricle (LV) dilation and sustained LV contraction compared with the other groups. The MDSC sheet formed aligned myotubes and produced a significant increase in capillary density and a reduction of myocardial fibrosis compared with the other groups. Hearts transplanted with the MDSC sheets did not display any significant arrhythmias and the donor MDSC survival rate was higher than the direct myocardial MDSC injection group. MDSC sheet implantation yielded better functional recovery of chronic infarcted myocardium without any significant arrhythmic events compared with direct MDSC injection, suggesting this cell sheet delivery system could significantly improve the myocardial regenerative potential of the MDSCs.

Bone marrow stem cells

The "mesenchymal stem cells (MSCs)" are cells adherent in the bone marrow, which can be isolated to induce differentiation. In contrast to the "embryonic stem cells" whose goal is to develop a new organism, the "MSC adult stem cells" can participate in tissue growth and repair throughout postnatal life. Addition of 5-azacytidine to MSCs in vitro induces the gradual increase in cellular size and begins spontaneous beatings, thereafter differentiating into cardiomyocytes. The "Methods" and "Protocols" to induce structural and functional maturations of MSCs, thus to achieve "Cellular Cardiomyoplasty," are described. With appropriate media, differentiations of MSCs to various kinds of cells such as chondrocytes, osteocytes, and adipocytes are also achievable.

Immune responses after mesenchymal stem cell implantation

Stem cell transplantation is a promising approach for improving cardiac function after severe myocardial damage for which use of autologous cells have been preferred to avoid immune rejection. Recently, however, rodent as well as human mesenchymal stromal cells (MSCs) have been reported to be uniquely immune tolerant, both in in vitro as well as in vivo transplant models. In this chapter, we summarize the current understanding of the underlying immunologic mechanisms, which can facilitate the use of such cells as "universal donor cells."

Cellular cardiomyoplasty: its past, present, and future

Cellular cardiomyoplasty is a cell therapy using stem cells or progenitor cells for myocardial regeneration to improve cardiac function and mitigate heart failure. Since we first published cellular cardiomyoplasty in 1989, this procedure became the innovative method to treat damaged myocardium other than heart transplantation. A significant improvement in cardiac function, metabolism, and perfusion is generally observed in experimental and clinical studies, but the improvement is mild and incomplete. Although safety, feasibility, and efficacy have been well documented for the procedure, the beneficial mechanisms remain unclear and optimization of the procedure requires further study. This chapter briefly reviews the stem cells used for cellular cardiomyoplasty and their clinical outcomes with possible improvements in future studies.

Improvement of cardiac contractile function in rats with postinfarction cardiosclerosis after transplantation of mononuclear and multipotent stroma bone marrow cells

We compared the efficiency of autologous mononuclear cells and multipotent stromal cells of the bone marrow after their non-selective intracoronary transplantation on day 30 after acute coronary infarction in rats. Improvement of hemodynamic parameters of myocardial contractility (rates of left ventricular pressure rise and drop) in comparison with the initial values and deceleration of postinfarction prolongation of QRS and QT intervals were observed in rats of the experimental group in contrast to controls in 4 weeks after transplantation. These functional changes were more intensive after transplantation of multipotent stromal cells and were accompanied by more pronounced morphological signs of reverse myocardial remodeling: thickening of the scarred left ventricular wall, shrinkage of the scar, and decrease in left ventricular dilatation index.

TGF-β family signaling in stem cells

BACKGROUND

The diversity of cell types and tissue types that originate throughout development derives from the differentiation potential of embryonic stem cells and somatic stem cells. While the former are pluripotent, and thus can give rise to a full differentiation spectrum, the latter have limited differentiation potential but drive tissue remodeling. Additionally cancer tissues also have a small population of self-renewing cells with stem cell properties. These cancer stem cells may arise through dedifferentiation from non-stem cells in cancer tissues, illustrating their plasticity, and may greatly contribute to the resistance of cancers to chemotherapies.

SCOPE OF REVIEW

The capacity of the different types of stem cells for self-renewal, the establishment and maintenance of their differentiation potential, and the selection of differentiation programs are greatly defined by the interplay of signaling molecules provided by both the stem cells themselves, and their microenvironment, the niche. Here we discuss common and divergent roles of TGF-β family signaling in the regulation of embryonic, reprogrammed pluripotent, somatic, and cancer stem cells.

MAJOR CONCLUSIONS

Increasing evidence highlights the similarities between responses of normal and cancer stem cells to signaling molecules, provided or activated by their microenvironment. While TGF-β family signaling regulates stemness of normal and cancer stem cells, its effects are diverse and depend on the cell types and physiological state of the cells.

GENERAL SIGNIFICANCE

Further mechanistic studies will provide a better understanding of the roles of TGF-β family signaling in the regulation of stem cells. These basic studies may lead to the development of a new therapeutic or prognostic strategies for the treatment of cancers. This article is part of a Special Issue entitled Biochemistry of Stem Cells.

Efficient cardiomyogenic differentiation of bone marrow mesenchymal stromal cells by combination of Wnt11 and bone morphogenetic protein 2

Wnt11 and bone morphogenetic protein 2 (BMP-2) are key signaling factors for stem cell differentiation into functional cardiomyocytes (CMs). In this study, we elucidate the biological effect of BMP-2 and Wnt11 on bone marrow mesenchymal stromal cells (BM-MSCs) that differentiate into myocardial-like cells in a simulated myocardial microenvironment in vitro. A cell co-culture system was established with recombinant Wnt11 treatment of NIH/3T3 cells and CMs. BMP-2 was added in a diverse schedule to induce cardiomyogenic differentiation of BM-MSCs co-cultured under various conditions. The levels of cardiac-specific markers Nkx2.5, α-myosin heavy chain ( α-MHC), β-myosin heavy chain ( β-MHC) and cardiac troponin I (cTnI) were determined by reverse transcriptase polymerase chain reaction and immunocytochemistry to evaluate cardiomyogenic differentiation. Wnt11 or BMP-2 used on their own to differentiate BM-MSCs resulted in no expression of α-MHC and cTnI. Wnt11 alone in a myocardial microenvironment enhanced cardiomyogenic differentiation. BMP-2 demonstrated a dose-dependent effect on BM-MSC differentiation into myocardial-like cells. Addition of BMP to BM-MSCs at various time points resulted in varying effects on cardiomyogenic differentiation. The combination of Wnt11 and BMP-2 treatment in a temporal manner significantly enhanced cardiomyogenic differentiation of BM-MSCs, with high expressions of α-MHC, β-MHC, Nkx2.5 and cTnI upon co-culture with CMs. Our study demonstrates that the combination of Wnt11 and BMP-2 effectively promotes cardiomyogenic differentiation of BM-MSCs in vitro. The synergistic effect of Wnt11 and BMP-2 on the cardiomyogenic differentiation of BM-MSCs is further enhanced in a myocardial microenvironment.

Transplantation with autologous mesenchymal stem cells after acute myocardial infarction evaluated by magnetic resonance imaging: an experimental study

PURPOSE

The purpose of this study was to track and investigate the effects of autologous bone marrow-derived mesenchymal stem cells (MSCs) transplantation after acute myocardial infarction in swine assessed by magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Twenty-four Chinese mini-pigs (27±3 kg) were divided into 4 groups, including control groups (groups 1 and 3) and MSCs transplantation groups (group 2, super paramagnetic iron oxide labeled and group 4, 4',6-diamidino-2-phenylindole labeled). Super paramagnetic iron oxide-labeled and 4',6-diamidino-2-phenylindole-labeled MSCs (3.0×10⁶ cells/mL) with a volume of 10 mL were injected into the left anterior descending artery by a catheter at 1 week after acute myocardial infarction, respectively. Cell distribution, cardiac functions, and scar tissue were quantitatively assessed by MRI.

RESULTS

The reduction of the T2* value in the myocardium, spleen, and liver in group 2 was significantly greater than that in group 1. MRI showed that function and scar size at baseline and 3 days after cell infusion were not significantly different between groups 1 and 2. Six weeks later left ventricular ejection fraction (P<0.0001), end-systolic volume (P<0.05), the number of dyskinetic segments (P<0.0001), left ventricular weight index (P<0.0001), and the infarcted size (P<0.0001) in group 4 were all improved comparing with those in group 3.

CONCLUSIONS

The majority of MSCs entrapped by the extracardial organs were mainly in the spleen. Catheter-based delivery of autologous bone marrow-derived MSCs into infarcted myocardium is feasible and effective.

Isogenic mesenchymal stem cells transplantation improves a rat model of chronic aristolochic acid nephropathy via upregulation of hepatic growth factor and downregulation of transforming growth factor β1

Chronic aristolochic acid (AA) nephropathy (CAAN) caused by intake of AA-containing herbs is difficult to treat. We evaluated the therapeutic effect of bone marrow (BM) mesenchymal stem cells (MSCs) on a rat model of CAAN. Female Wistar rats were fed with decoction of Caulis Aristolochia manshuriensis by intragastric administration. MSCs were prepared from BM of male Wistar rats and injected into female CAAN rats through tail vein. Body weight, renal function, and urinary excretion of these CAAN rats were monitored before killing at the end of the 20th week. Blood, urine, and tissue samples were collected from experimental (MSC and non-MSC) and normal control groups. All animals developed renal fibrosis after 12 weeks of intake of AA-containing decoction. Fibrosis in the MSC groups was significantly reduced as examined with light and electron microscopy. Blood urea nitrogen, serum creatinine, and urine protein levels were significantly reduced and hemoglobin levels were improved in the MSC group as compared with the non-MSC group (p < 0.01). The expression of TGF-β1 mRNA and protein was reduced but hepatic growth factor (HGF) was increased in the MSC group compared with the non-MSC group, but still higher than the normal control level as measured by immunochemical, RT-PCR, and western blotting assays (p < 0.01). The renal fibrosis of CAAN could be protected by isogenic MSC transplantation, probably via upregulation of HGF and downregulation of TGF-β1.

Pathophysiology of stroke and stroke-induced retinal ischemia: emerging role of stem cells

The current review focuses on pathophysiology, animal models and molecular analysis of stroke and retinal ischemia, and the role of stem cells in recovery of these disease conditions. Research findings associated with ischemic stroke and retinal ischemia have been discussed, and efforts towards prevention and limiting the recurrence of ischemic diseases, as well as emerging treatment possibilities with endothelial progenitor cells (EPCs) in ischemic diseases, are presented. Although most neurological diseases are still not completely understood and reliable treatment is lacking, animal models provide a major step in validating novel therapies. Stem cell approaches constitute an emerging form of cell-based therapy to treat ischemic diseases since it is an attractive source for regenerative therapy in the ischemic diseases. In this review, we highlight the advantages and limitations of this approach with a focus on key observations from preclinical animal studies and clinical trials. Further research, especially on treatment with EPCs is warranted.

Tendon-derived stem cells (TDSCs): from basic science to potential roles in tendon pathology and tissue engineering applications

Traditionally, tendons are considered to only contain tenocytes that are responsible for the maintenance, repair and remodeling of tendons. Stem cells, which are termed tendon-derived stem cells (TDSCs), have recently been identified in tendons. This review aims to summarize the current information about the in vitro characteristics of TDSCs, including issues related to TDSC isolation and culture, their cell morphology, immunophenotypes, proliferation and differentiation characteristics and senescence during in vitro passaging. The challenges in studying the functions of these cells are also discussed. The niche where TDSCs resided essentially provides signals that are conducive to the maintenance of definitive stem cell properties of TDSCs. Yet the niche may also induce pathologies by imposing an aberrant function on TDSCs or other targets. The possible niche factors of TDSCs are herein discussed. We presented current evidences supporting the potential pathogenic role of TDSCs in the development of tendinopathy with reference to the recent findings on the altered biological responses of these cells in response to their potential niche factors. The use of resident stem cells may promote engraftment and differentiation of transplanted cells in tendon and tendon-bone junction repair because the tendon milieu is an ideal and familiar environment to the transplanted cells. Evidences are presented to show the potential advantages and results of using TDSCs as a new cell source for tendon and tendon-bone junction repair. Issues pertaining to the use of TDSCs for tissue repair are also discussed.

Protective effects of trimetazidine on bone marrow mesenchymal stem cells viability in an ex vivo model of hypoxia and in vivo model of locally myocardial ischemia

Bone marrow mesenchymal stem cells (MSCs) have shown potential for cardiac repair following myocardial injury, but this approach is limited by their poor viability after transplantation. The present study was to investigate whether trimetazidine (TMZ) could improve survival of MSCs in an ex vitro model of hypoxia, as well as survival, differentiation, and subsequent activities of transplanted MSCs in rat hearts with acute myocardial infarction (AMI). MSCs at passage 3 were examined for their viability and apoptosis under a transmission electron microscope, and by using flow cytometry following culture in serum-free medium and exposure to hypoxia (5% CO(2), 95% N(2)) for 12 h with or without TMZ. Thirty Wistar rats were divided into 3 groups (n=10 each group), including group I (AMI control), group II (MSCs transplantation alone), and group III (TMZ+MSCs). Rat MSCs (4×10(7)) were injected into peri-infarct myocardium (MSCs group and TMZ+MSCs group) 30 min after coronary artery ligation. The rats in TMZ+MSCs group were additionally fed on TMZ (2.08 mg·kg(-1)·day(-1)) from day 3 before AMI to day 28 after AMI. Cardiac structure and function were assessed by echocardiography at 28th day after transplantation. Blood samples were collected before the start of TMZ therapy (baseline), and 24 and 48 h after AMI, and inflammatory cytokines (CRP, TNF-α) were measured. Then the survival and differentiation of transplanted cells in vivo were detected by immunofluorescent staining. The cellular apoptosis in the peri-infarct region was detected by using TUNEL assay. Furthermore, apoptosis-related proteins (Bcl-2, Bax) within the post-infarcted myocardium were detected by using Western blotting. In hypoxic culture, the TMZ-treated MSCs displayed a two-fold decrease in apoptosis under serum-free medium and hypoxia environment. In vivo, cardiac infarct size was significantly reduced, and cardiac function significantly improved in MSCs and TMZ+MSCs groups as compared with those in the AMI control group. Combined treatment of TMZ with MSCs implantation demonstrated further decreased MSCs apoptosis, further increased MSCs viability, further decreased infarct size, and further improved cardiac function as compared with MSCs alone. The baseline levels of inflammatory cytokines (CRP, TNF-α) had no significant difference among the groups. In contrast, all parameters at 24 h were lower in TMZ+MSCs group than those in MSCs group. Furthermore, Western blotting indicated that the expression of anti-apoptotic protein Bcl-2 was up-regulated, while the pro-apoptotic protein Bax was down-regulated in the TMZ+MSCs group, compared with that in the MSCs group. It is suggested that implantation of MSCs combined with TMZ treatment is superior to MSCs monotherapy for MSCs viability and cardiac function recovery.

Myocardial regeneration with bone-marrow-derived stem cells

Despite significant therapeutic advances, heart failure remains the predominant cause of mortality in the Western world. Ischaemic cardiomyopathy and myocardial infarction are typified by the irreversible loss of cardiac muscle (cardiomyocytes) and vasculature composed of endothelial cells and smooth muscle cells, which are essential for maintaining cardiac integrity and function. The recent identification of adult and embryonic stem cells has triggered attempts to directly repopulate these tissues by stem cell transplantation as a novel therapeutic option. Reports describing provocative and hopeful examples of myocardial regeneration with adult bone-marrow-derived stem and progenitor cells have increased the enthusiasm for the use of these cells, yet many questions remain regarding their therapeutic potential and the mechanisms responsible for the observed therapeutic effects. In this review article we discuss the current preclinical and clinical advances in bone-marrow-derived stem or progenitor cell therapies for regeneration or repair of the ischaemic myocardium and their multiple related mechanisms involved in myocardial repair and regeneration.

Immortalization of bone marrow-derived porcine mesenchymal stem cells and their differentiation into cells expressing cardiac phenotypic markers

Mesenchymal stem cells (MSCs) may be among the first stem cell types to be utilized in the clinic for cell therapy, because of their ease of isolation and extensive differentiation potential. Using a porcine model, we have established several cell lines from MSCs to facilitate in vitro and in vivo studies of their potential use for cellular therapy. Bone marrow-derived primary MSCs were immortalized using the pRNS-1 plasmid. We obtained four stable immortalized cell lines that exhibited higher proliferative capacities than the parental cells. All four cell lines displayed a common phenotype similar to that of primary mesenchymal cells, characterized by constitutively high expressions of CD90, CD29, CD44, SLA I and CD46, while CD172a, CD106 and CD56 were less expressed. Remarkably, treatment with 5-azacytidine-stimulated porcine MSCs lines to differentiate into cells that were positive for cardiac phenotypic markers, such as α-actin, connexin-43, sarcomeric actin, serca-2 and, to a lesser extent, desmin and troponin-T. These porcine MSC lines will be valuable biological tools for developing strategies for ex vivo expansion and differentiation of MSCs into a specific lineage.

Transplantation of induced bone marrow mesenchymal stem cells improves the cardiac function of rabbits with dilated cardiomyopathy via upregulation of vascular endothelial growth factor and its receptors

Bone marrow mesenchymal stem cells (BMMSCs) have shown promise in repairing injured myocardium. However, few studies have explored the potential of BMMSC transplantation for dilated cardiomyopathy (DCM). In this study we aimed to examine whether BMMSC transplantation improves the cardiac function of dilated cardiomyopathy and investigate the underlying mechanism. We established a DCM model in rabbit, then transplanted BMMSCs induced by 5-azacytidine into the rabbit, and determined the left ventricular pressure and the expression of vascular endothelial growth factor (VEGF) and its receptors. Immunohistochemisty, ultrastructural and reverse transcription polymerase chain reaction (RT-PCR) analysis proved that 5-azacytidine induced the differentiation of BMMSCs into cardiomyocyte-like cells. Upon transplantation of the induced BMMSCs into a DCM model, significantly higher maximum rates of rise and decline (±d p/d t) of left ventricular pressure and left ventricular systolic pressure, as well as much lower left ventricular diastolic pressure, were observed compared with the control group ( P < 0.05). After four weeks, deposition of collagen fibers in the myocardium of transplantation group was reduced, accompanied by increased expression of VEGF and its receptors as detected by RT-PCR. Taken together, our results suggest that BMMSC transplantation could alleviate DCM through angiogenesis via the upregulation of VEGF and its receptors.

Transdifferentiation: why and how?

Cell therapy is based on the replacement of damaged cells in order to restore injured tissues. The first consideration is that an abundant source of cells is needed; second, these cells should be immunologically compatible with the guest and third, there should be no real threat of these cells undergoing malignant transformation in the future. Given these requirements, already differentiated adult cells or adult stem cells obtained from the body of the patient appear to be the ideal candidates to meet all of these demands. The utilization of somatic cells also avoids numerous ethical and political drawbacks and concerns. Transdifferentiation is the phenomenon by which an adult differentiated cell switches to another differentiated cell. This paper reviews the importance of transdifferentiation, discussing the cells that are suitable for this process and the methods currently employed to induce the change in cell type.

Cardiac cell therapy and arrhythmias

Cardiac stem cell based therapy is a promising therapy for patients with severe heart failure. Many types of stem cells, such as embryonic stem cells, myoblasts, marrow-derived mesenchymal stem cells, circulating endothelial progenitor cells, and cardiac precursor cells etc, are known as cellular sources for cardiac stem cell therapy. Both in the clinical and experimental setting, stem cells are reported, and supposed, to cause some arrhythmogenic adverse effects. In order to overcome these serious adverse effects, it is necessary to know the electrophysiological properties of stem cell-derived cardiomyocytes, and have a profound insight into the mechanisms of arrhythmia to know whether such arrhythmogenic properties of the cells can cause serious arrhythmia in situ. In the present study, recent publications that focus on the electrophysiological aspect of stem cell based therapy are reviewed and, furthermore, a new perspective on cardiac stem cell therapy of arrhythmias is given.

Stromal vascular fraction transplantation as an alternative therapy for ischemic heart failure: anti-inflammatory role

BACKGROUND

The aims of this study were: (1) to show the feasibility of using adipose-derived stromal vascular fraction (SVF) as an alternative to bone marrow mono nuclear cell (BM-MNC) for cell transplantation into chronic ischemic myocardium; and (2) to explore underlying mechanisms with focus on anti-inflammation role of engrafted SVF and BM-MNC post chronic myocardial infarction (MI) against left ventricular (LV) remodelling and cardiac dysfunction.

METHODS

Four weeks after left anterior descending coronary artery ligation, 32 Male Lewis rats with moderate MI were divided into 3 groups. SVF group (n = 12) had SVF cell transplantation (6 × 10(6) cells). BM-MNC group (n = 12) received BM-MNCs (6 × 10(6)) and the control (n = 10) had culture medium. At 4 weeks, after the final echocardiography, histological sections were stained with Styrus red and immunohistochemical staining was performed for α-smooth muscle actin, von Willebrand factor, CD3, CD8 and CD20.

RESULTS

At 4 weeks, in SVF and BM-MNC groups, LV diastolic dimension and LV systolic dimension were smaller and fractional shortening was increased in echocardiography, compared to control group. Histology revealed highest vascular density, CD3+ and CD20+ cells in SVF transplanted group. SVF transplantation decreased myocardial mRNA expression of inflammatory cytokines TNF-α, IL-6, MMP-1, TIMP-1 and inhibited collagen deposition.

CONCLUSIONS

Transplantation of adipose derived SVF cells might be a useful therapeutic option for angiogenesis in chronic ischemic heart disease. Anti-inflammation role for SVF and BM transplantation might partly benefit for the cardioprotective effect for chronic ischemic myocardium.