Electrostimulation induces cardiomyocyte predifferentiation of fibroblasts

Cardiac Regeneration Laboratories, Heart, Lung, and Esophageal Surgery Institute, University of Pittsburgh Medical Center and McGowan Institute for Regenerative Medicine, 3025 Carson Street, Pittsburgh, PA 15203, USA.
Biochemical and Biophysical Research Communications (Impact Factor: 2.3). 07/2008; 370(3):450-5. DOI: 10.1016/j.bbrc.2008.03.115
Source: PubMed


Stem-cell therapy has become a promising therapeutic tool for myocardial repair. Cardiac pre-committed cells, which complete their differentiation in the myocardium, may reduce fibrosis and restore muscle function. However, many questions concerning a precise, functional integration of injected cells remain unanswered. Fibroblasts regulate the cardiac extracellular matrix and are the most abundant cell population in an infarcted area. Electrostimulation is a well-known trophic factor and can induce phenotypic changes in myoblasts. The objective of this study was to evaluate the effectiveness of electrical stimulation to induce pre-commitment of fibroblasts into cardiomyocytes in vitro. Using short-time electrostimulation in a cytokine-free culture system, we induced pre-commitment of two fibroblast cell lines to a cardiomyocyte phenotype. This partial differentiation in vitro may facilitate further differentiation within the cardiac environment and result in better electro-mechanical integration of the therapeutically introduced cells.

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Available from: Cristiano Spadaccio
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    • "While studies with several cell types have shown that acute electrical stimulation can promote differentiation of cells toward cardiomyocyte phenotype891011121314, we have now shown that acute electrical stimulation increased cardiac differentiation of human iPSCs. In iPS(Foreskin)-2 cell line, acute electrical stimulation at 200 mV/mm for 5 min modestly but significantly increased the rate of cardiac differentiation of human iPSCs by twofold (Figure 3(b)). "
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    ABSTRACT: Human induced pluripotent stem cells (iPSCs) are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods . Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs) for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results . In iPS(Foreskin)-2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1 , TNNT2 , MYH7 , and MYL7 . However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac-specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration-dependent manner. Conclusions . Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used.
    Full-text · Article · Jan 2016 · Stem cell International
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    • "Furthermore, cellular uptake of these electroactive nanoparticles [4] [5] provides a platform for the manipulation of MSC differentiation pathways using electrical stimulation. Previous studies have shown that electrical stimulation promotes a range of cell responses including reorientation and angiogenesis [6], muscle cell regeneration [7e9], myogenesis of fibroblasts [10] [11], cardiomyogenesis of embryonic stem cells [12e14] and enhanced cardiomyocyte phenotype [15e17]. Some of the initial attempts at promoting cardiomyogenesis using mesenchymal stem cells (MSC) involved the use of the controversial demethylating agent 5-azacytidine [18], which has been shown to induce apoptosis in vivo [19]. "
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    ABSTRACT: Once damaged, cardiac muscle has little intrinsic repair capability due to the poor regeneration potential of remaining cardiomyocytes. One method of overcoming this issue is to deliver functional cells to the injured myocardium to promote repair. To address this limitation we sought to test the hypothesis that electroactive carbon nanotubes (CNT) could be employed to direct mesenchymal stem cell (MSC) differentiation towards a cardiomyocyte lineage. Using a two-pronged approach, MSCs exposed to medium containing CNT and MSCs seeded on CNT based polylactic acid scaffolds were electrically stimulated in an electrophysiological bioreactor. After electrical stimulation the cells reoriented perpendicular to the direction of the current and adopted an elongated morphology. Using qPCR, an upregulation in a range of cardiac markers was detected, the greatest of which was observed for cardiac myosin heavy chain (CMHC), where a 40-fold increase was observed for the electrically stimulated cells after 14 days, and a 12-fold increase was observed for the electrically stimulated cells seeded on the PLA scaffolds after 10 days. Differentiation towards a cardioprogenitor cell was more evident from the western blot analysis, where upregulation of Nkx2.5, GATA-4, cardiac troponin t (CTT) and connexin43 (C43) was seen to occur. This was echoed in immunofluorescent staining, where increased levels of CTT, CMHC and C43 protein expression were observed after electrical stimulation for both cells and cell-seeded scaffolds. More interestingly, there was evidence of increased cross talk between the cells as shown by the pattern of C43 staining after electrical stimulation. These results establish a paradigm for nanoscale biomimetic cues that can be readily translated to other electroactive tissue repair applications.
    Full-text · Article · Jun 2012 · Biomaterials
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    • "Using 21 days of electrostimulation, cell proliferation was 40% higher than control non-stimulated cells (P=0.01). Previous studies showed a high incidence of cell death after electrostimulation.12–14 This is the first time that higher cell proliferation after three weeks of electrostimulation than control group has been demonstrated. "
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    ABSTRACT: Electrostimulation (ES) can be defined as a safe physical method to induce stem cell differentiation. The aim of this study is to evaluate the effectiveness of ES on bone marrow mesenchymal stem cells (BMSCs) seeded in collagen scaffolds in terms of proliferation and differentiation into cardiomyocytes. BMSCs were isolated from Wistar rats and seeded into 3D collagen type 1 templates measuring 25 × 25 × 6 mm. Bipolar in vitro ES was performed during 21 days. Electrical impedance and cell proliferation were measured. Expression of cardiac markers was assessed by immunocytochemistry. Viscoelasticity of collagen matrix was evaluated. Electrical impedance assessments showed a low resistance of 234±41 Ohms which indicates good electrical conductivity of collagen matrix. Cell proliferation at 570 nm as significantly increased in ES groups after seven day (ES 0.129±0.03 vs non-stimulated control matrix 0.06±0.01, P=0.002) and after 21 days, (ES 0.22±0.04 vs control 0.13±0.01, P=0.01). Immunocytoche mistry of BMSCs after 21 days ES showed positive staining of cardiac markers, troponin I, connexin 43, sarcomeric alpha-actinin, slow myosin, fast myosin and desmin. Staining for BMSCs marker CD29 after 21 days was negative. Electrostimulation of cell-seeded collagen matrix changed stem cell morphology and biochemical characteristics, increasing the expression of cardiac markers. Thus, MSC-derived differentiated cells by electrostimulation grafted in biological scaffolds might result in a convenient tissue engineering source for myocardial diseases.
    Full-text · Article · Jun 2012 · Heart International
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