The purpose of this study was to observe whether human peripheral dervied monouncleas cells (hMNCs) could participate in the regeneration process of the ischemic hearts in the way of differentiating into cardiomyocytes, vascular endothelial cells and smooth muscle cells. hMNCs were transplanted into the bodies of the mice with myocardial infarction through the tail vein injection. Hearts were harvested 2-12 weeks after injection then sliced up into frozen sections of 5 micron thickness. Double immunofluorescence staining was used to test the differentiation of the grafted cells into cardiomyocytes, smooth muscle cells and vascular endothelial cells which revealed that cells expressing both HLA and TNT, HLA and alpha-SMA, HLA and vWF existed in the hearts of the mice. According to the study, it is probable that hMNCs could participate in the regeneration process of the infarcted hearts in the way of differentiation.
Animals ; Cell Differentiation ; physiology ; Humans ; Leukocytes, Mononuclear ; transplantation ; Mice ; Mice, Nude ; Myocardial Infarction ; pathology ; therapy ; Myocytes, Cardiac ; cytology ; Transplantation, Heterologous

OBJECTIVETo investigate whether injectable engineering heart tissue (EHT) can survive and improve heart function after transplantation into infarct area.

METHODSVentricular cardiomyocytes from 1-3 day-old Sprague-Dawley (SD) rats were isolated by using trypsin method, and then labeled and cultured. The left coronary of female SD rats was ligated to create a myocardial infarct model. Three weeks later, the qualified animals were randomized into four groups: EHT group (n = 12), which were transplanted with both cardiomyocytes and matrix; cell transplantation group (n = 12); matrix group (n = 12), control (n = 11). Four weeks after implantation, echocardiography and Langendorff model were used to assess heart function, and then the hearts were harvested for pathological examination. Meanwhile polymerase chain reaction (PCR) was performed to detect SRY gene on Y chromosome.

RESULTSThe grafted cells were identified in both EHT and cell transplantation group by either pathology or PCR. But in EHT group, transplanted cells formed more condensed tissue, and produced definite connected protein. Data of fraction shortness from echocardiography are showed as follows: EHT group, (22.82 +/- 3.44)%; cell transplantation group, (20.55 +/- 4.11)%, matrix group, (17.05 +/- 4.57)%; control, (19.80 +/- 3.98)% (P = 0.012). Langendorff examination revealed significant differences among four groups when left ventricular balloon volume was at the level of 0.06 ml, 0.08 ml and 0.10 ml, in which EHT group had the highest developed pressure and dp/dt.

CONCLUSIONIt is feasible to fabricate injectable EHT in vitro. The fabricated EHT could survive in the myocardial infarct area after transplantation in a rat model and improve heart function due to better histological configuration.

Animals ; Cell Transplantation ; methods ; Echocardiography ; Female ; Myocardial Infarction ; physiopathology ; surgery ; Myocytes, Cardiac ; transplantation ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering

OBJECTIVETo investigate whether heart tissue-derived extracellular matrix (ECM) promotes the differentiation of cardiosphere-derived cells (CDCs) implanted in rat infracted myocardium to improve the cardiac structure and function.

METHODSRat CDCs were cultured by cardiac explant methods, and ECM was prepared by decelluariztion method. In a Wistar rat model of acute myocardial infarction established by ligating the left anterior descending branch, IMDM solution, ECM suspension, 10CDCs in IMDM solution, or 10CDCs in ECM suspension were injected into the infracted rat myocardium (6 rats in each group). The cardiac function of the rats was evaluated by cardiac ultrasonography, and the percentage of positive heart fibrosis area after infarction was determined with Masson staining. The differentiation of implanted CDCs in the infarcted myocardium was detected using immunofluorescence assay for the markers of cardiac muscle cells (α-SA), vascular endothelial cells (vWF) and smooth muscle cells (α-SMA).

RESULTSThree weeks after acute myocardial infarction, the rats with injection of CDCs in ECM showed the highest left ventricular ejection fraction (LVEF) and percentage of fraction shortening with the lowest percentage of positive heart fibrosis area; implantation of CDCs with ECM resulted in significantly higher rates of CDC differentiation into cardiac muscle cells, vascular endothelial cells and smooth muscle cell (P<0.05).

CONCLUSIONHeart-tissue derived ECM significantly promotes the differentiation of CDCs implanted in the infracted myocardium into cardiac muscle cells, vascular endothelial cells and smooth muscle cells to improve the cardiac structure and cardiac functions in rats.

Animals ; Cell Differentiation ; Cells, Cultured ; Disease Models, Animal ; Endothelial Cells ; cytology ; Extracellular Matrix ; transplantation ; Myocardial Infarction ; therapy ; Myocardium ; Myocytes, Cardiac ; transplantation ; Myocytes, Smooth Muscle ; cytology ; Rats ; Rats, Wistar

In developed countries, in which people have nutrient-rich diets, convenient environments, and access to numerous medications, the disease paradigm has changed. Nowadays, heart failure is one of the major causes of death. In spite of this, the therapeutic efficacies of medications are generally unsatisfactory. Although whole heart transplantation is ideal for younger patients with heart failure, many patients are deemed to be unsuitable for this type of surgery due to complications and/or age. The need for therapeutic alternatives to heart transplantation is great. Regenerative therapy is a strong option. For this purpose, several cell sources have been investigated, including intrinsic adult stem or progenitor cells and extrinsic pluripotent stem cells. Most intrinsic stem cells seem to contribute to a regenerative environment via paracrine factors and/or angiogenesis, whereas extrinsic pluripotent stem cells are unlimited sources of cardiomyocytes. In this review, we summarize the various strategies for using regenerative cardiomyocytes including our recent progressions: non-genetic approaches for the purification of cardiomyocytes and efficient transplantation. We expect that use of intrinsic and extrinsic stem cells in combination will enhance therapeutic effectiveness.
Animals ; Embryonic Stem Cells/cytology ; Humans ; Myocardium/*cytology/*metabolism ; Myocytes, Cardiac/*cytology ; *Regeneration ; Stem Cell Transplantation ; Tissue Engineering

OBJECTIVETo evaluate the therapeutic potential of marrow-derived cardiac stem cell (MCSC) transplantation after myocardial infarction (MI) in rats.

METHODSMCSC were selected from the marrow mesenchymal stem cell (MMSC) of male SD rats by single-cell cloning culture. MI was induced by left anterior descending artery ligating in female SD rats. Equal volume PBS, MMSC and MCSC were transplanted at the border zone of the infarct one week after MI. Cardiac function was assessed by echocardiography at four weeks after cell transplantation. The hearts were removed and morphological changes of scar tissue were examined with HE staining and Masson trichrome staining, VEGFR-1(+) capillary vessels were labeled with immunohistochemical staining. Scar area and vessel density were measured by image analyzer. MCSC containing Y chromosome were examined using in situ fluorescent hybridization, and cardiomyocyte cTnT expression was also analyzed.

RESULTSCardiac transcription factor Nkx2.5 was expressed at low level in c-kit(+) MCSC. Four weeks after cell transplantation, left ventricular fractional shortening and ejection fraction were significantly higher while scar area was significantly lower in MCSC group compared to MMSC group and control group. cTnT was expressed in cells containing Y chromosome and these cells were connected with myocardium of recipient rats in the rats transplanted with MCSC. Vessel density around the infarcted tissue in MCSC group was similar as that in MMSC group and significantly higher than that in control group.

CONCLUSIONMSCS could effectually differentiate into functional cardiomyocytes at the border zone of the infarct, and MCSC transplantation post MI significantly improved cardiac functions and promoted angiogenesis.

Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Disease Models, Animal ; Female ; Myocardial Infarction ; therapy ; Myocytes, Cardiac ; transplantation ; Rats ; Rats, Sprague-Dawley ; Stem Cell Transplantation

Congestive heart failure (CHF) has emerged as a major worldwide epidemic and its main causes seem to be the aging of the population and the survival of patients with post-myocardial infarction. Cardiomyocyte dropout (necrosis and apoptosis) plays a critical role in the progress of CHF; thus treatment of CHF by exogenous cell implantation will be a promising medical approach. In the acute phase of cardiac damage cardiac stem cells (CSCs) within the heart divide symmetrically and/or asymmetrically in response to the change of heart homeostasis, and at the same time homing of bone marrow stem cells (BMCs) to injured area is thought to occur, which not only reconstitutes CSC population to normal levels but also repairs the heart by differentiation into cardiac tissue. So far, basic studies by using potential sources such as BMCs and CSCs to treat animal CHF have shown improved ventricular remodelling and heart function. Recently, however, a few of randomized, double-blind, placebo-controlled clinical trials demonstrated mixed results in heart failure with BMC therapy during acute myocardial infarction.
Animals ; Clinical Trials as Topic ; trends ; Heart Failure ; pathology ; surgery ; Humans ; Mesenchymal Stem Cell Transplantation ; methods ; trends ; Myocytes, Cardiac ; transplantation ; Practice Guidelines as Topic ; Practice Patterns, Physicians' ; trends

We observed in a pilot study that there was a transient elevation of brain natriuretic peptide (BNP) level shortly after the transplantation in the patient with ischemic heart failure, which is unexplainable by the simultaneous increase of the cardiac output and six-minute walk distance. Similar findings were observed in the phase I trial. We postulated on the basis of the finding of Fukuda in vitro that this transient elevation of BNP level against the improvement of cardiac function and exercise capacity might indicate cardiomyogenesis in patients after mesenchymal stem cell transplantation. Further study is warranted to verify the hypothesis.
Adult ; Aged ; Female ; Humans ; Male ; Mesenchymal Stem Cell Transplantation ; Middle Aged ; Muscle Development ; Myocytes, Cardiac ; physiology ; Natriuretic Peptide, Brain ; physiology ; Transplantation, Autologous ; Ventricular Remodeling

Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Humans ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; Myocardial Infarction ; surgery ; Myocytes, Cardiac ; cytology

OBJECTIVETo explore the feasibility of magnetic resonance imaging (MR) on detecting transplanted nanometer small superparamagnetic iron oxides (SPIO) labeled mesenchymal stem cells (MSCs) in swine model with acute myocardial infarction (MI).

METHODSMSCs isolated from swine were incubated with nanometer SPIO for 24 hours and the third-passage MSCs were labeled with DNA dye 4'-6-diamidino-2-phenylindole (DAPI) and aliphatic red fluorescent dye PKH(26)-GL. Presence of small particles of SPIO in MSCs was assessed by Prussian Blue staining and electron microscopy. Three animals in each group received SPIO-labeled MSCs (5 x 10(5); 1 x 10(6); 2 x 10(6)) and MSCs without SPIO (1 x 10(6)) injections into the infarcted myocardium approximately 1 hour following left anterior descending coronary artery. MRI (1.5-T) was performed 20 to 24 hours post infarction in all animals and the animals were subsequently sacrificed for histology 1 hour post MRI.

RESULTSIn vitro Prussian Blue staining and electron microscopy examination revealed numerous iron particles in the cytoplasm of MSCs. Low signal intensity spots with the scanning T(2)(*)WI-Flash 2d sequence were detected in all SPIO-MSCs but not in SPIO-negative-MSCs injected myocardial sites in vivo with the clinical 1.5 T scanner. Prussian blue, DAPI and PKH(26) positive cells were detected histologically in sections corresponding to low signal intensity spots area shown on MRI.

CONCLUSIONMagnetically labeled MSCs transplanted in myocardial ischemia area of swine can be visualized in vivo with a clinical 1.5-T MRI and could be used for tracking SPIO-MSCs clinically.

Animals ; Biomarkers ; Disease Models, Animal ; Ferrosoferric Oxide ; Magnetic Resonance Imaging ; methods ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; Myocardial Infarction ; pathology ; surgery ; Myocytes, Cardiac ; Nanoparticles ; Swine

The effects of cardiomyocyte grafting on left ventricular (LV) remodeling and function in rats with chronic myocardial infarction were evaluated using high-frequency ultrasound. Chronic myocardial infarction was induced in 50 Wister rats by ligating the left anterior descending artery. They were randomized into two groups: a trial group that received neonatal rat cardiomyocyte transplantation (n=25) and a control group which were given intramyocardial injection of culture medium (n=25). The left ventricular (LV) geometry and function were evaluated by high-frequency ultrasound before and 4 weeks after the cell transplantation. After the final evaluation, all rats were sacrificed for histological study. The results showed that 4 weeks after the cell transplantation, as compared with the control group, the LV end-systolic dimension, end-diastolic dimension, end-systolic volume and end-diastolic volume were significantly decreased and the LV anterior wall end-diastolic thickness, LV ejection fraction and fractional shortening were significantly increased in the trial group (P<0.01). Histological study showed that transplanted neonatal rat cardiomyocytes were found in all host hearts and identified by Brdu staining. It was suggested that transplantation of neonatal rat cardiomyocytes can reverse cardiac remodeling and improve heart function in chronic myocardial infarction rats. High-frequency ultrasound can be used as a reliable technique for the non-invasive evaluation of the effect of cardiomyocyte transplantation.
Animals, Newborn ; Echocardiography/*methods ; Myocardial Infarction/physiopathology ; Myocardial Infarction/*therapy ; Myocardial Infarction/ultrasonography ; Myocytes, Cardiac/*transplantation ; Random Allocation ; Rats, Wistar ; Ventricular Function, Left/*physiology ; Ventricular Remodeling