Electrophysiological characteristics of cardiomyocyte-like cells from rat bone marrow derived mesenchymal stem cells by four inductors.

BACKGROUND: Bone marrow derived mesenchymal stem cells (BMdMSCs) can differentiate into cardiomyocyte-like cells induced by different inductors individually or collectively. In this study, by inducing BMdMSCs with p53 inhibitor (p-fifty three inhibitor-alpha, PFT-α), 5-azacytidine (5-AZA), angiotensin-II (Ang-II) and bone morphogenic protein-2 (BMP-2) we compared the influences of four inductors on the differentiation of rat BMdMSCs into caridomyocyte like-cells. METHODS: BMdMSCs were collected from the bone marrow of Sprague Dawley rats and after the fourth generation, the purified cells were divided into five groups: 5-AZA (10 µmol/L), Ang-II (0.1 µmol/L), PFT-α (20 µmol/L), BMP-2 (10 µg/L) and control. The purity of the BMdMSCs and the cardiac differentiation rates were obtained by flow cytometry. The expressions of cTnT in the BMdMSCs after four weeks of induction were detected by immunofluorescence and the expressions of cTnI and Cx43 detected by Western blotting. The green fluorescent levels reflecting intracellular calcium transient function were determined by laser scanning confocal microscopy. The total potassium current levels of cells were measured on patch clamp. RESULTS: All inductors affected to a different degree the differentiation of BMdMSCs into cardiomyocyte-like cells and the expressions of cTnT, cTnI and Cx43 suggesting that the combination of inductors could be an improved method for cardiac regenerative medicine. In addition, the total potassium current level and calcium transient in PFT-α cardiomyocyte-like cells were higher than other groups. CONCLUSIONS: The cardiac differentiation of BMdMSCs induced by PFT-α, 5-AZA, Ang-II and BMP-2 has been improved at different levels. PFT-α has an advantage of differentiation rate and electrophysiological function over other inductors.

Combination of BMP-2 and 5-AZA is advantageous in rat bone marrow-derived mesenchymal stem cells differentiation into cardiomyocytes.

Bone morphogenetic protein-2 (BMP-2) has a crucial role in the development of cardiogenesis, and is used in inducing bone marrow mesenchymal stem cells (BMMSCs) to differentiate into cardiomyocytes. We have examined a combination of BMP-2 and 5-azacytidine (5-AZA) in inducing these differentiation effects. BMMSCs were collected and purified from bone marrow of 4-week-old Sprague-Dawley (SD) rats by density-gradient centrifugation and differential attachment. The fourth passage subculture of BMMSCs, selected by cytometry for purity and identification, was divided into four groups: a control group, BMP-2 treated, 5-AZA treated, and a combination of BMP-2 and 5-AZA treatment. Expression of cardiac Troponin I (cTnI) and Connexin 43 (CX-43) in BMMSCs after induction were detected by immunofluorescence and Western blot. Flow cytometry analysis was used for differentiation rates and apoptosis of induced BMMSCs, through the expression of cardiac Troponin T (cTnT) and Annexin V-FITC & PI kit, respectively. BMP-2 can ameliorate apoptosis of BMMSCs caused by 5-AZA and promote the differentiation of BMMSCs into cardiomyocyte-like cells. Thus a combination of BMP-2 and 5-AZA can significantly improve the cardiac differentiation with fewer cell damage effects, making it a safe and effective method of induction in vitro.

Stress-induced growth-differentiation factor 15 plays an intriguing role in cardiovascular diseases.

OBJECTIVE: To provide an overview of the current knowledge of growth-differentiation factor 15 (GDF-15) in heart disease. DATA SOURCES: To identify relevant publications, we searched PubMED database combining the textual terms of heart, cardiac, cardiovascular disease with GDF-15. STUDY SELECTION: Well-controlled, relatively large-scale, retrospective studies as well as meaningful individual cases were all selected as materials. RESULTS: GDF-15 is a distant member of the transforming growth factor-ß cytokine superfamily. In myocardium, GDF-15 is weakly expressed under physiological conditions. However, its expression level is increased in response to pathological stress. Growing evidence indicate that elevated levels of GDF-15 is a promising prognostic biomarker in cardiovascular diseases. Moreover, GDF-15 exhibits the properties of endogenous anti-hypertrophy of cardiomyocytes and protecting the heart suffering from ischemia and reperfusion insult. CONCLUSION: Ve GDF-15 may be a promising biomarker for evaluation and management of patient with cardiovascular diseases, and have potential protective properties on myocardium.

Cardiac differentiation and electrophysiology characteristics of bone marrow mesenchymal stem cells.

OBJECTIVE: To review the progress of cardiac differentiation and electrophysiological characteristics of bone marrow mesenchymal stem cells. DATA SOURCES: The databases of PubMed, Springer Link, Science Direct and CNKI were retrieved for papers published from January 2000 to January 2012 with the key words of "bone marrow mesenchymal stem cells, cardiac or heart, electrophysiology or electrophysiological characteristics". STUDY SELECTION: The articles concerned cardiac differentiation and electrophysiological characteristics of bone marrow mesenchymal stem cells were collected. After excluding papers that study purposes are not coincident with this review or contents duplicated, 56 papers were internalized at last. RESULTS: For the treatment of myocardial infarction and myocardiac disease, the therapeutic effects of transplantation of bone marrow mesenchymal stem cells which have the ability to develop into functional myocardial cells by lots of methods have been proved by many researches. But the arrhythmogenic effect on ventricles after transplantation of bone marrow mesenchymal stem cells derived myocardial cells is still controversial in animal models. Certainly, the low differentiation efficiency and heterogeneous development of electrical function could be the most important risk for proarrhythmia. CONCLUSION: Many studies of cardiac differentiation of bone marrow mesenchymal stem cells have paid attention to improve the cardiac differentiation rate, and the electrophysiology characteristics of the differentiated cells should be concerned for the risk for proarrhythmia as well.