N-cadherin mimetic hydrogel enhances MSC chondrogenesis through cell metabolism

Mesenchymal stem cells (MSCs) are ideal candidates for tissue engineering and regenerative medicine because of their proliferative capacity and differentiation potential. However, the hypertrophic phenotype occurring in late MSCs chondrogenic differentiation severely limits their clinical translation. While hypertrophy inhibition strategies have been explored, the role of cell metabolism in MSCs chondrogenesis has rarely been studied. In this study, we found that hypertrophy occurred in the late stage of MSCs chondrogenesis with increased fatty acid oxidation (FAO) and decreased glycolysis, as well as cell-cell junctions impairment. Therefore, a N-cadherin mimetic hydrogel was developed to enhance cell-cell junctions via N-cadherin mimetic peptides and high seeding density. The N-cadherin mimetic hydrogel attenuated hypertrophy through regulating glycolysis and FAO. The regulation of cell-cell junctions mechanotransduction on cell metabolism was partly mediated by Hif-1α. In addition, 2D and 3D culture of N-cadherin mimetic hydrogel had similar functions on N-cadherin expression and chondrogenesis in MSCs. Our study is the first to reveal that metabolic remodeling induced hypertrophy during MSCs chondrogenesis, and indicate the effect of N-cadherin mimetic hydrogel on hypertrophy inhibition of MSCs. STATEMENT OF SIGNIFICANCE: The development of hypertrophy during MSCs chondrogenesis severely limits its clinical translation. Various strategies have been explored to inhibit hypertrophy by chemical and/or mechanical stimulation. However, the role of cell metabolism in MSCs chondrogenesis has rarely been studied. In this study, we developed an RNA sequencing at day 0, 7, and 21 of MSCs chondrogenesis to clarify the mechanisms that mediate hypertrophy. We found that hypertrophy occurred in the late stage of MSCs chondrogenesis with increased FAO and decreased glycolysis, as well as impaired cell-cell junctions. We also found that N-cadherin mimetic hydrogel attenuated hypertrophy and enhanced chondrogenesis through regulating glycolysis and FAO. Our finding provides new insights into the application of MSCs in tissue engineering and regenerative medicine.