Subthreshold High-Frequency Electrical Field Stimulation Induces VEGF Expression in Cardiomyocytes

Abstract

Subthreshold electrical stimulation (SES) has been shown to induce an improvement of angiogenesis in ischemic and nonischemic skeletal muscles, mediated by increased VEGF expression. VEGF plays a key role in physiological and pathological angiogenesis. Cardiomyocytes possess the ability to synthesize and secrete VEGF. Thus, we thought to investigate the effect of SES on VEGF regulation in cultured neonatal rat ventricular myocytes (NRVMs), in the aim to reveal new techniques for therapeutic angiogenesis in ischemic heart disease. Cell cultures of NRVMs were electrically stimulated with field strengths below the myocyte depolarization threshold (0.5 V/cm with 1 ms bipolar impulse duration). Frequencies ranging from 5 Hz up to 25, 50, and 99 Hz were applied over a period of 48 h. The expression of VEGF and its receptor KDR was determined with Western blot and ELISA. To reveal the biological activity of the secreted VEGF amount, cultured human coronary artery endothelial cells (HCAECs) were treated with the cell culture supernatant of NRVMs exposed to SES. A dominant effect of SES was observed at 25 Hz. Within this particular frequency the VEGF protein amount in the cytoplasm as well as in the cell culture supernatant increased significantly. In parallel, the protein expression of the KDR receptor decreased in a significant manner. Moreover, cell culture supernatant of NRVMs exposed to SES augmented the growth of HCAECs. Cardiomyocytes respond to SES with an increase in biologically active VEGF expression that promotes cell proliferation of HCAECs. This mechanism may provide new approaches to develop therapeutic angiogenesis in the ischemic heart.

Production of bioactive recombinant human myeloid‐derived growth factor in Escherichia coli and its mechanism on vascular endothelial cell proliferation

“…Moreover, as we all known, VEGF is a highly specific pro-vascular endothelial growth factor with strong ability to promote vascular proliferation. 22 Interestingly, we observed that the proliferation of HCAECs induced by rhMYDGF was almost similar to that of VEGF treatment, and its EC 50 was 7.09 ± 0.04 ng/ mL. Notably, the results of the three independent experimental assays (CCK8, BrdU and MTT assays) for cell proliferation showed that…”

Maturation of human induced pluripotent stem cell derived engineered cardiac tissues using chief transfection and chronic optical pacing.

“…25 This result suggests electrical stimulation can induce angiogenesis through VEGF production. 25 Because electricity induces cardiac maturity, many clinical cell therapy and tissue engineering research methods apply electrical stimulation paradigms. Skeletal progenitor cells, used for cell therapy, respond to electrical pacing similarly to cardiac cell types.…”

“…24 Calcium signaling is complemented by VEGF production in the mechanistic response to electrical pacing, and this VEGF production can induce angiogenesis in immature cardiac cells. 25 Rackauskas et al, utilizing subthreshold high-frequency electrical field stimulation on NVRMs, induced secretion and protein expression of VEGF. 25 Furthermore, VEGF secretions into the cell media promoted proliferation of human coronary artery endothelial cells, promoting angiogenesis.…”

“…25 Rackauskas et al, utilizing subthreshold high-frequency electrical field stimulation on NVRMs, induced secretion and protein expression of VEGF. 25 Furthermore, VEGF secretions into the cell media promoted proliferation of human coronary artery endothelial cells, promoting angiogenesis. 25 This result suggests electrical stimulation can induce angiogenesis through VEGF production.…”

“…25 Furthermore, VEGF secretions into the cell media promoted proliferation of human coronary artery endothelial cells, promoting angiogenesis. 25 This result suggests electrical stimulation can induce angiogenesis through VEGF production. 25 Because electricity induces cardiac maturity, many clinical cell therapy and tissue engineering research methods apply electrical stimulation paradigms.…”