Chondrogenic potential of animal adult stem cells through electrical stimulation

Abstract

Background & Aim Mesenchymal stem cells (MSCs) represent an appealing alternative cell source for cartilage repair. There are studies that induce differentiation into cartilage cells by treating the growth factors in MSCs or altering the properties of MSCs by genetic modification. Electrical stimulation (ES) is known to guide the development and regeneration of many tissues. Use of low-frequency ES for therapeutic purposes has been increasing during the last decades. In this study, we exposed equine adipose tissue-derived MSCs (eAD-MSCs) to ES and assessed changes in the chondrogenic differentiation potential. Methods, Results & Conclusion The cells obtained from equine adipose tissue attached to culture plates and expanded in vitro. Flow cytometric analysis at third passage indicated that the cells were strongly positive for CD44, CD90, and CD105, but negative for CD13, CD34, and CD45. ES was applied to eAD-MSCs cultured under condition of high-density micro-mass under ES of 10 V/cm, with duration of 10 ms and a frequency of 2.0 Hz for three days. We compared chondrogenic differentiation potential of non-ES and ES condition. Expression levels of chondrogenic potential-related markers were examined by quantitative real-time RT-PCR. Articular cartilage is divided into a hyaline cartilage layer and a fibrous cartilage layer. Osteoarthritis (OA) is a disease caused by the natural degeneration of cartilage layer. From the beginning, OA of the middle stage leads to damage of the hyaline cartilage, and damage of the fibrous cartilage at the last stage. We observed the differentiation potential of eAD-MSCs into chondrocytes by specific ES in absence of exogenous growth factors. Gene expression of chondrogenic markers such as type II collagen (COL2A1), Aggrecan, and Sox9 was analyzed at 3 days of ES. Based on the mechanism that chondrocyte formation in articular cavity starts from the aggregation of cells, we observed the differentiation potential of eAD-MSCs into chondrocytes by specific ES in absence of exogenous growth factors. Therefore, this study might contribute to the differentiation of stem cells into cartilage cells by inducing pre-chondrogenic condensation under specific ES.