Autologous bone marrow-derived progenitor cell transplantation for myocardial regeneration after acute infarction

Effects of Neuropeptide Y on Stem Cells and Their Potential Applications in Disease Therapy

Neuropeptide Y (NPY), a 36-amino acid peptide, is widely distributed in the central and peripheral nervous systems and other peripheral tissues. It takes part in regulating various biological processes including food intake, circadian rhythm, energy metabolism, and neuroendocrine secretion. Increasing evidence indicates that NPY exerts multiple regulatory effects on stem cells. As a kind of primitive and undifferentiated cells, stem cells have the therapeutic potential to replace damaged cells, secret paracrine molecules, promote angiogenesis, and modulate immunity. Stem cell-based therapy has been demonstrated effective and considered as one of the most promising treatments for specific diseases. However, several limitations still hamper its application, such as poor survival and low differentiation and integration rates of transplanted stem cells. The regulatory effects of NPY on stem cell survival, proliferation, and differentiation may be helpful to overcome these limitations and facilitate the application of stem cell-based therapy. In this review, we summarized the regulatory effects of NPY on stem cells and discussed their potential applications in disease therapy.

Generation and characterization of human cardiac resident and non-resident mesenchymal stem cell

Despite the surgical and other insertional interventions, the complete recuperation of myocardial disorders is still elusive due to the insufficiency of functioning myocardiocytes. Thus, the use of stem cells to regenerate the affected region of heart becomes a prime important. In line with this human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have gained considerable interest due to their potential use for mesodermal cell based replacement therapy and tissue engineering. Since MSCs are harvested from various organs and anatomical locations of same organism, thus the cardiac regenerative potential of human cardiac-derived MSCs (hC-MSCs) and human umbilical cord Wharton's Jelly derived MSC (hUC-MSCs) were tested concurrently. At in vitro culture, both hUC-MSCs and hC-MSCs assumed spindle shape morphology with expression of typical MSC markers namely CD105, CD73, CD90 and CD44. Although, hUC-MSCs and hC-MSCs are identical in term of morphology and immunophenotype, yet hUC-MSCs harbored a higher cell growth as compared to the hC-MSCs. The inherent cardiac regenerative potential of both cells were further investigated with mRNA expression of ion channels. The RT-PCR results demonstrated that both MSCs were expressing a notable level of delayed rectifier-like K(+) current (I KDR ) ion channel, yet the relative expression level was considerably varied between hUC-MSCs and hC-MSCs that Kv1.1(39 ± 0.6 vs 31 ± 0.8), Kv2.1 (6 ± 0.2 vs 21 ± 0.12), Kv1.5 (7.4 ± 0.1 vs 6.8 ± 0.06) and Kv7.3 (27 ± 0.8 vs 13.8 ± 0.6). Similarly, the Ca2(+)-activated K(+) current (I KCa ) channel encoding gene, transient outward K(+) current (I to ) and TTX-sensitive transient inward sodium current (I Na.TTX ) encoding gene (Kv4.2, Kv4.3 and hNE-Na) expressions were detected in both groups as well. Despite the morphological and phenotypical similarity, the present study also confirms the existence of multiple functional ion channel currents IKDR, IKCa, Ito, and INa.TTX in undifferentiated hUC-MSCs as of hC-MSCs. Thus, the hUC-MSCs can be exploited as a potential candidate for future cardiac regeneration.

Clinical application of adult stem cells for therapy for cardiac disease

INTRODUCTION

Cardiovascular disease is a major cause of death worldwide. Different medical and surgical therapeutic options are well established, but a significant number of patients are not amenable to standard therapeutic options. Cell-based therapies after clinical application have shown different results in recent years. Here, we are giving a comprehensive overview on major available clinical data regarding cell therapy.

BACKGROUND

Cell-based therapies and tissue engineering provide new promising platforms to develop upcoming therapeutic options. Initial clinical trials were able to generate promising results. A variety of different stem cell types have been used for the clinical application. Different adult cardiac stem cells and progenitor cells, including mesenchymal, CD34(+) and CD133(+) autologous human bone marrow-derived stem cells (BMCs), human myoblasts, and peripheral blood-derived stem and progenitor cells (PBSCs) have been used for the therapy for end-stage heart failure. Future experiments will show the importance of novel cell populations and clarify the mechanism causing cell therapy-mediated observed effects.

CONCLUSION

Several clinical trials have reported on sole therapy, as well as combined application of autologous adult stem cells with conventional revascularization. The reported promising findings encourage further research in the field of the translational research.

Introduction to stem cells and regenerative medicine

Stem cells are a population of undifferentiated cells characterized by the ability to extensively proliferate (self-renewal), usually arise from a single cell (clonal), and differentiate into different types of cells and tissue (potent). There are several sources of stem cells with varying potencies. Pluripotent cells are embryonic stem cells derived from the inner cell mass of the embryo and induced pluripotent cells are formed following reprogramming of somatic cells. Pluripotent cells can differentiate into tissue from all 3 germ layers (endoderm, mesoderm, and ectoderm). Multipotent stem cells may differentiate into tissue derived from a single germ layer such as mesenchymal stem cells which form adipose tissue, bone, and cartilage. Tissue-resident stem cells are oligopotent since they can form terminally differentiated cells of a specific tissue. Stem cells can be used in cellular therapy to replace damaged cells or to regenerate organs. In addition, stem cells have expanded our understanding of development as well as the pathogenesis of disease. Disease-specific cell lines can also be propagated and used in drug development. Despite the significant advances in stem cell biology, issues such as ethical controversies with embryonic stem cells, tumor formation, and rejection limit their utility. However, many of these limitations are being bypassed and this could lead to major advances in the management of disease. This review is an introduction to the world of stem cells and discusses their definition, origin, and classification, as well as applications of these cells in regenerative medicine.

5-Azacytidine induces cardiac differentiation of human umbilical cord-derived mesenchymal stem cells by activating extracellular regulated kinase

5-Azacytidine (5-Aza) induces differentiation of mesenchymal stem cells (MSCs) into cardiomyocytes. However, the underlying mechanisms are not well understood. Our previous work showed that 5-Aza induces human bone marrow-derived MSCs to differentiate into cardiomyocytes. Here, we demonstrated that 5-Aza induced cardiac differentiation of human umbilical cord-derived MSCs (hucMSCs) and explored the potential signaling pathway. Our results showed that hucMSCs had cardiomyocyte phenotypes after 5-Aza treatment. In addition, myogenic cells differentiated from hucMSCs were positive for mRNA and protein of desmin, β-myosin heavy chain, cardiac troponin T, A-type natriuretic peptide, and Nkx2.5. Human diploid lung fibroblasts treated with 5-Aza expressed no cardiac-specific genes. 5-Aza did not induce hucMSCs to differentiate into osteoblasts. Further study revealed that 5-Aza treatment activated extracellular signal related kinases (ERK) in hucMSCs, but protein kinase C showed no response to 5-Aza administration. U0126, a specific inhibitor of ERK, could inhibit 5-Aza-induced expression of cardiac-specific genes and proteins in hucMSCs. Increased phosphorylation of signal transducers and activators of transcription 3, and up-regulation of myocyte enhancer-binding factor-2c and myogenic differentiation antigen in 5-Aza-treated hucMSCs were also suppressed by U0126. Taken together, these results suggested that sustained activation of ERK by 5-Aza contributed to the induction of the differentiation of hucMSCs into cardiomyocytes in vitro.

[Evaluation of the therapeutic effect of hyperbaric oxygenation and erythropoietin in the treatment of chronic heart failure using myocardial perfusion scintigraphy G-SPECT]

BACKGROUND

The most important predictors of long-term survival in patients with cardiac ischemic disease are left ventricular ejection fraction, left ventricular volumes, infarction size, presence and extent of residual myocardial ischemia. One of the most important recent developments in single photon emission computed tomography (SPECT) myocardial perfusion imaging is the ability to acquire these studies in conjunction with electrocardiogram (ECG) gating (G-SPECT). The ability to asses radionuclide myocardial perfusion and function with ECG G-SPECT imaging has revolutionized this field of nuclear cardiology. Study with G-SPECT development algorithms permits to quantify measures of left ventricular (LV) volume, ejection fraction (LVEF) and even regional myocardial wall motion and thickening. The American Society of Nuclear Cardiology (ASNC) in its position paper from March 1999 recommends the routine incorporation of G-SPECT during cardiac perfusion scintigraphy.

CASE REPORT

We presented a 70-year-old male with ischemic heart disease (dilatative, cardiomyopathy and absolute arrhythmia). He was few times hospitally treated by medicamentous therapy with no evidence of improvement. After hospital treatment, we included hyperbaric oxygenation (HBO) and erythropoietin injections. Hyperbaric oxygenation was carried out in a monoplace hyperbaric chamber, BLK S-303, by a graduated protocol for patients with severe heart insufficiency, totally 15 treatments. Recombinant erythropoietin beta (RecormonR F. Hoffmann-La Roche) was applied deeply subcutaneously, every second day from 2000 IU to totally 16000 IU. Before the therapy G-SPECT study was performed with 99m technetium-MIBI, and we obtained the functional parameters and perfusion of the left ventricle to follow-up the therapy effects. The study was performed by an ADAC-VERTEX PLUS-EPIC two-head gamma camera with dedicated quantitatively algorithm Auto-QUANT. The results of LVEF were 15%, with severity abnormal motion and wall thickening for all segments. Left ventricle end-diastolic volume was 393 ml (normal < 142 ml), and LV end-systolic volume was 334 ml (normal < 65 ml). Four months after the therapy G-SPECT showed improvement in any parameters; LVEF 25%, with improvement in wall motion (normalized wall motion in the anterior, lateral area, and proximal septum) and wall thickening, LV end-diastolic volume was 390 ml, LV end-systolic volume was 289 ml.

CONCLUSION

Using G-SPECT method before and after the therapy with hyperbaric oxygenation and erythropoietin we obtained objective improvement and good therapy effects in the treatment of chronic heart insufficiency.

Bone marrow-derived stem/progenitor cells: their use in clinical studies for the treatment of myocardial infarction

Over the last six years, several centres around the world have started clinical trials to investigate the utilisation of bone marrow-derived cells for myocardial infarction. Different types and numbers of cells have been used assuming they possess a potential to originate new endothelial cells and/or cardiomyocytes to repair/regenerate the ailed heart. Despite diversity in number, clinical status of subjects, route of cell administration, and criteria to evaluate efficacy, the main conclusion drawn from these clinical studies was that such therapies were safe. However, attempts to unify efficacy data have yielded no clear answers, so far. This review offers an in-depth and critical analysis of these trials and intends to evaluate from the cellular biology and clinical cardiology viewpoints, the significant information that has been published since 2002, as well as that emerging from ongoing clinical trials. Emphasis will be placed on cellular types, research designs and methods to evaluate efficacy of each particular treatment modality.

Colony-forming cells in rat myocardium after destructive exposure and intramyocardial transplantation of bone marrow cells

The content of colony-forming cells in myocardial cell culture from the perinecrotic zone of rat heart was evaluated on day 40 after cryodestruction. The mean cellularity after cryodestruction was 12-fold lower than in intact animals. Intramyocardial transplantation of bone marrow cells (mononuclears, mesenchymal stem cells, and mesenchymal stem cells treated with 5-azacitidine) into the perinecrotic zone increased the content of colony-forming cells. After transplantation of mesenchymal stem cells and mesenchymal stem cells treated with 5-azacitidine, the number of colonies reached 33 +/- 7 and 11 +/- 3, the mean cellularity being 2975 +/- 80 and 1105 +/- 42 cells/cm2, respectively. Hence, intramyocardial transplantation of mesenchymal stem cells created an appreciable pool of colony-forming cells in the myocardial perinecrotic zone. Treatment with 5-azacitidine reduced survival of mesenchymal stem cells after intramyocardial transplantation.

[Stem cells use in the treatment of neurologic disorders--has the future already arrived?]

<zakljucak> Buducnost celijske terapije u lecenju neuroloskih bolesti je pocela. Ostaju vazna pitanja na koja odgovor mogu dati samo dobro osmisljene medjunarodne studije, a ticu se vrste celija, nacina njihovog umnozavanja i aplikacije, kao i optimalnog vremenskog okvira za ovakvu vrstu lecenja.

Peripheral blood hematopoietic stem cells: Biology, apheresis collection and cryopreservation

Introduction Hematopoiesis is a continuous, dynamic and highly complex process resulting in production of various mature blood cells from a small population of pluripotent stem and progenitor cells through diverse proliferative and differentiative events. Numerous studies have demonstrated that a complex network of interactive cytokines regulates the survival, maturation, and proliferation of hematopoietic stem and progenitor cells (HSPCs). Application of cell-mediated therapy Massive application of different cell-mediated therapeutic methods has resulted in an increased need for both specific HSPCs and operating procedures providing minimal cell damage during collection, processing and storage in a liquid or frozen state. Therefore, the basic aim of cell harvesting, selection, as well as cryopreservation is to minimize cell damage during these procedures. HSPCs are cells which exhibit extensive self-renewal and proliferative capacity, associated with the capacity to differentiate into all blood cells and other cell lineages (plasticity of HSPC). Thanks to these properties, stem cells can provide complete and permanent restoration of hematopoiesis, which is the basis for clinical employment of HSPC transplantation. In addition, totipotent stem cells can be used for the so called "cell-therapy" in different clinical settings (e.g. myocardial regeneration after acute infarction). Conclusion Despite the fact that HSPC transplantation is already in routine use, some questions related to the optimal blood progenitor/cell collection, selection, storage and clinical use are still unresolved. Therefore, this review only briefly discusses the therapeutic use of HSPCs in different clinical areas and focuses on the recommendations, as well as the specific transfusion policies related to HSPC collection, processing, and cryopreservation with an emphasis on quality control.

Autologous bone marrow-derived progenitor cell myocardial delivery for recent myocardial infarction patients following early angioplasty: results from a pilot study

PURPOSE

Cellular cardiomyoplasty is a potential therapeutic approach to preventing left ventricular remodeling after myocardial infarction and has shown encouraging results such as induction of neoangiogenesis and functional improvement of diseased hearts. We report the results of a pilot study on progenitor cells in five patients with acute myocardial infarction (AMI).

MATERIALS AND METHODS

Patients with single-vessel disease who had their first episode of myocardial infarction and underwent angioplasty after 48 h (an average of 17 days following myocardial infarction) were included in the study. Mononuclear cells (MNCs) (1x10(7)) were isolated by Ficoll Hypaque method from 60 ml of bone marrow (BM) obtained from the iliac crest of 5 patients (aspiration was performed under local anesthesia). The mean CD34 count was 1-4%. After confirming the patency of the affected vessel postangioplasty, cellular concentrate was injected into the affected artery in 3-ml boluses (three to four injections), with intermittent occlusion.

RESULTS

The mean age of all five male patients was 48.6+13.7 years. At 1 year, five patients were asymptomatic, and one had Class II dyspnea on exertion. The results of an echocardiogram performed at 6 months showed an improvement in ejection fraction (EF) from 35.3% to 43.13% and in fractional shortening from 24.75% to 28.33%. End-systolic volume decreased from 115.5 to 92.3 ml, end-diastolic volume decreased from 177.5 to 170 ml, and end-systolic dimensions also decreased from 4.26 to 4 mm, demonstrating positive left ventricular remodeling. Repeat echocardiogram at 1 year showed persistent improvement in EF. No adverse events were noted either before or after the procedure.

CONCLUSION

The injection of autologous BM MNCs is a safe and efficacious therapy following early revascularization in AMI patients.

Bone marrow mesenchymal stem cells differentiate into functional cardiac phenotypes by cardiac microenvironment

Heart attacks and congestive heart failure remain among the world's most prominent health challenges despite the many breakthroughs. Bone marrow mesenchymal stem cells (BMSCs) have the potential to transdifferentiate into myocytes if an appropriate cardiac environment is provided. This study is meant to investigate the ability of BMSCs to differentiate into cardiomyocytes in a conditioned medium. BMSCs were isolated from rat femurs and tibias using Percoll gradient centrifugation method. Cells were expanded as undifferentiated cells in culture for more than 3 passages and their phenotypes were identified with flow cytometer. BMSCs were cocultured with neonatal rat ventricular myocytes in a rate of 1:10 separated by semipermeable membrane. BMSCs marker of CD29 were highly expressed (98.89+/-1.2%); however, CD34 could hardly be identified (5.61+/-0.1%). After coculturing with myocytes, some of BMSCs showed contraction which became more regular and more vigorous. As assessed by RT-PCR, SERCA2 and RyR(2) were expressed by newly formed cells from 1 to 3 weeks. Immunostaining of newly differentiated BMSCs revealed positivity for cTnT. Some of these cells were positive for sarcomeric alpha-actinin, desmin, cTnT, and cTnI. Western blotting showed that cTnI protein expression was upregulated in these cells from 1 to 3 weeks. Newly formed BMSCs exhibited ultrastructural features of sarcomere formation and inward rectifier potassium current (I(K1)). It is concluded that BMSCs possess the potential to differentiate into cardiomyocytes in the cardiac environment. BMSCs provide an excellent model for development of stem cell therapeutics, and their potential in the cardiac repair under various pathological conditions.

Iron particles for noninvasive monitoring of bone marrow stromal cell engraftment into, and isolation of viable engrafted donor cells from, the heart

Stem cells offer a promising approach to the treatment of myocardial infarction and prevention of heart failure. We have used iron labeling of bone marrow stromal cells (BMSCs) to noninvasively track cell location in the infarcted rat heart over 16 weeks using cine-magnetic resonance imaging (cine-MRI) and to isolate the BMSCs from the grafted hearts using the magnetic properties of the donor cells. BMSCs were isolated from rat bone marrow, characterized by flow cytometry, transduced with lentiviral vectors expressing green fluorescent protein (GFP), and labeled with iron particles. BMSCs were injected into the infarct periphery immediately following coronary artery ligation, and rat hearts were imaged at 1, 4, 10, and 16 weeks postinfarction. Signal voids caused by the iron particles in the BMSCs were detected in all rats at all time points. In mildly infarcted hearts, the volume of the signal void decreased over the 16 weeks, whereas the signal void volume did not decrease significantly in severely infarcted hearts. High-resolution three-dimensional magnetic resonance (MR) microscopy identified hypointense regions at the same position as in vivo. Donor cells containing iron particles and expressing GFP were identified in MR-targeted heart sections after magnetic cell separation from digested hearts. In conclusion, MRI can be used to track cells labeled with iron particles in damaged tissue for at least 16 weeks after injection and to guide tissue sectioning by accurately identifying regions of cell engraftment. The magnetic properties of the iron-labeled donor cells can be used for their isolation from host tissue to enable further characterization.

Contemplating the bright future of stem cell therapy for cardiovascular disease

Not long ago, it was assumed that mammalian hearts were so differentiated that regeneration of cardiac tissue was not possible, but now an increasing amount of information suggests that the intrinsic regenerative capacity of the heart can be encouraged by stimulating resident stem cells or transplanting extracardiac progenitor cells. In the future, cardiovascular stem cell therapy may be administered to all patients. Here, we review what has happened and look at where we are going.

Improved graft mesenchymal stem cell survival in ischemic heart with a hypoxia-regulated heme oxygenase-1 vector

OBJECTIVES

The goal of this study was to modify mesenchymal stem cells (MSCs) cells with a hypoxia-regulated heme oxygenase-1 (HO-1) plasmid to enhance the survival of MSCs in acute myocardial infarction (MI) heart.

BACKGROUND

Although stem cells are being tested clinically for cardiac repair, graft cells die in the ischemic heart because of the effects of hypoxia/reoxygenation, inflammatory cytokines, and proapoptotic factors. Heme oxygenase-1 is a key component in inhibiting most of these factors.

METHODS

Mesenchymal stem cells from bone marrow were transfected with either HO-1 or LacZ plasmids. Cell apoptosis was assayed in vitro after hypoxia-reoxygen treatment. In vivo, 1 x 10(6) of male MSC(HO-1), MSC(LacZ), MSCs, or medium was injected into mouse hearts 1 h after MI (n = 16/group). Cell survival was assessed in a gender-mismatched transplantation model. Apoptosis, left ventricular remodeling, and cardiac function were tested in a gender-matched model.

RESULTS

In the ischemic myocardium, the MSC(HO-1) group had greater expression of HO-1 and a 2-fold reduction in the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end labeling-positive cells compared with the MSC(LacZ) group. At seven days after implantation, the survival MSC(HO-1) was five-fold greater than the MSC(LacZ) group; MSC(HO-1) also attenuated left ventricular remodeling and enhanced the functional recovery of infarcted hearts two weeks after MI.

CONCLUSIONS

A hypoxia-regulated HO-1 vector modification of MSCs enhances the tolerance of engrafted MSCs to hypoxia-reoxygen injury in vitro and improves their viability in ischemic hearts. This demonstration is the first showing that a physiologically inducible vector expressing of HO-1 genes improves the survival of stem cells in myocardial ischemia.

Apheresis in donor and therapeutic settings: Recruitments vs. possibilities—a multicenter study

In our country, the first apheresis was performed in the late 1960s (by manual technique), and the first cell separator was used in 1979. The number of blood component collections performed from 1994 to 2004 was: 11,170 (total), i.e., 8540 (NBTI), 1180 (IT-MMA), 1050 (BTI of Novi Sad) and 400 (BTI Nis). The number of PBSC harvests during 1996-2004 was 386 for treatment of 272 patients. For treatment of myocardial infarction, "cell-therapy" by autologous stem cells was introduced in 2004 at the MMA. The results of PE treatments performed (7632 sessions) by our group for various immune-mediated and other disorders were generally beneficial, but the effect is not associated with bone marrow remission. TC procedures (total number=1279) resulted in a significant fall in the blood cell counts and hemorheological improvement, as well as the removal and replacement of abnormal red blood cells. Greater standardization of different apheresis protocols is required.