Electrical stimulation drives chondrogenesis of mesenchymal stem cells in the absence of exogenous growth factors

Abstract

Electrical stimulation (ES) is known to guide the development and regeneration of many tissues. However, although preclinical and clinical studies have demonstrated superior effects of ES on cartilage repair, the effects of ES on chondrogenesis remain elusive. Since mesenchyme stem cells (MSCs) have high therapeutic potential for cartilage regeneration, we investigated the actions of ES during chondrogenesis of MSCs. Herein, we demonstrate for the first time that ES enhances expression levels of chondrogenic markers, such as type II collagen, aggrecan, and Sox9, and decreases type I collagen levels, thereby inducing differentiation of MSCs into hyaline chondrogenic cells without the addition of exogenous growth factors. ES also induced MSC condensation and subsequent chondrogenesis by driving Ca2+/ATP oscillations, which are known to be essential for prechondrogenic condensation. In subsequent experiments, the effects of ES on ATP oscillations and chondrogenesis were dependent on extracellular ATP signaling via P2X4 receptors, and ES induced significant increases in TGF-β1 and BMP2 expression. However, the inhibition of TGF-β signaling blocked ES-driven condensation, whereas the inhibition of BMP signaling did not, indicating that TGF-β signaling but not BMP signaling mediates ES-driven condensation. These findings may contribute to the development of electrotherapeutic strategies for cartilage repair using MSCs.

Liquid Metal‐Based Multifunctional Micropipette for 4D Single Cell Manipulation

“…Note that, the proliferation rate is higher when the applied voltage is higher. Their findings agree with what prior works have suggested that electrical stimulation may induce cell proliferation or even differentiation 27, 28, 29. The proposed multifunctional pipette could have a potential use as a highly localized single cell electrical stimulator for biological studies and other applications, in addition to examples demonstrated in the current work.…”

Expression of miR-145-5p During Chondrogenesis of Mesenchymal Stem Cells

“…For example, timely application of TGF-β3 and BMP-2 in sequence is crucial for successful MSC chondrogenesis [19,20]. In addition, mechanical, electrical, or other material/ structural stimulations can initiate MSC chondrogenesis without the key stimuli such as TGF-βs or other molecules [21–23]. Real-time feedback with the miR-145-5p responsive reporter could help enhance timing of these events/stimuli to potentially facilitate these mechano-dynamic TE cartilage optimizations.…”

Diverse effects of pulsed electrical stimulation on cells - with a focus on chondrocytes and cartilage regeneration

“…For example, a pulse-number-dependent downregulation of mitochondrial function and cell numbers was observed by Hall et al (2007) for nsPEFs. 3 d of PES would not cause significant cell death, while 7 d of PES would cause significant cell death (Kwon et al, 2016). The formation of pores caused by PES increases due to the increase in pulse number (Yogesh, 2016).…”

“…PES has the unique ability to induce reversible pore formation in plasma membranes within seconds, (Pakhomov et al, 2015). Pores that form on plasma membranes are temporary and reversible when an electric field strength of about 0.1-20 kV/cm and pulse durations of 10 ns-10 ms are applied (Kirawanich et al, 2010;Kotnik et al, 2015). These temporary pores have been widely used in biomedical applications, including delivery of biomolecules, such as DNA, RNA, and proteins -commonly referred to as electroporation or electrofusion (Cemazar et al, 2013;Schoellhammer et al, 2014) -as well as drugs (Okino and Mohri, 1987).…”