T-L Tsai1, P A Manner, W-J Li. 1. Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, WI 53705, USA. tsai@ortho.wisc.edu
Abstract
OBJECTIVE: Effective induction of human mesenchymal stem cell (hMSC) differentiation for regenerative medicine applications remains a great challenge. While much research has studied hMSC activity during differentiation, it is unclear whether pre-differentiation culture can modulate differentiation capacity. We investigate the effect of glucose concentration in pre-differentiation/expansion culture on modulating chondrogenic capacity of hMSCs, and explore the underlying molecular mechanism. DESIGN: The extent of chondrogenesis of hMSCs previously cultured with different concentrations of glucose was evaluated. Transforming growth factor-beta (TGF-β) signaling molecules and protein kinase C (PKC) were analyzed to identify the role of these molecules in the regulation of glucose on chondrogenesis. In addition, hMSCs in high-glucose expansion culture were treated with the PKC inhibitor to modulate the activity of PKC and TGF-β signaling molecules. RESULTS: High-glucose maintained hMSCs were less chondrogenic than low-glucose maintained cells upon receiving differentiation signals. Interestingly, we found that high-glucose culture increased the phosphorylation of PKC and expression of type II TGF-β receptor (TGFβRII) in pre-differentiation hMSCs. However, low-glucose maintained hMSCs became more responsive to chondrogenic induction with increased PKC activation and TGFβRII expression than high-glucose maintained hMSCs during differentiation. Inhibiting the PKC activity of high-glucose maintained hMSCs during expansion culture upregulated the TGFβRII expression of chondrogenic cell pellets, and enhanced chondrogenesis. CONCLUSION: Our findings demonstrate the effect of glucose concentration on regulating the chondrogenic capability of pre-differentiation hMSCs, and provide insight into the mechanism of how glucose concentration regulates PKC and TGF-β signaling molecules to prime pre-differentiation hMSCs for subsequent chondrogenesis.
OBJECTIVE: Effective induction of human mesenchymal stem cell (hMSC) differentiation for regenerative medicine applications remains a great challenge. While much research has studied hMSC activity during differentiation, it is unclear whether pre-differentiation culture can modulate differentiation capacity. We investigate the effect of glucose concentration in pre-differentiation/expansion culture on modulating chondrogenic capacity of hMSCs, and explore the underlying molecular mechanism. DESIGN: The extent of chondrogenesis of hMSCs previously cultured with different concentrations of glucose was evaluated. Transforming growth factor-beta (TGF-β) signaling molecules and protein kinase C (PKC) were analyzed to identify the role of these molecules in the regulation of glucose on chondrogenesis. In addition, hMSCs in high-glucose expansion culture were treated with the PKC inhibitor to modulate the activity of PKC and TGF-β signaling molecules. RESULTS: High-glucose maintained hMSCs were less chondrogenic than low-glucose maintained cells upon receiving differentiation signals. Interestingly, we found that high-glucose culture increased the phosphorylation of PKC and expression of type II TGF-β receptor (TGFβRII) in pre-differentiation hMSCs. However, low-glucose maintained hMSCs became more responsive to chondrogenic induction with increased PKC activation and TGFβRII expression than high-glucose maintained hMSCs during differentiation. Inhibiting the PKC activity of high-glucose maintained hMSCs during expansion culture upregulated the TGFβRII expression of chondrogenic cell pellets, and enhanced chondrogenesis. CONCLUSION: Our findings demonstrate the effect of glucose concentration on regulating the chondrogenic capability of pre-differentiation hMSCs, and provide insight into the mechanism of how glucose concentration regulates PKC and TGF-β signaling molecules to prime pre-differentiation hMSCs for subsequent chondrogenesis.
Authors: Shailesh Agarwal; Shawn Loder; John Li; Cameron Brownley; Jonathan R Peterson; Eboda Oluwatobi; James Drake; David Cholok; Kavitha Ranganathan; Hsiao Hsin Sung; James Goulet; Shuli Li; Benjamin Levi Journal: Stem Cells Dev Date: 2015-10-01 Impact factor: 3.272
Authors: André Luiz A Pizzolatti; Florian Gaudig; Daniel Seitz; Carlos R M Roesler; Gean Vitor Salmoria Journal: Tissue Eng Regen Med Date: 2018-08-30 Impact factor: 4.169