Using growth factors to help stem cells differentiate into chondrocytes, or cartilage cells has been shown to be an effective way to maintain cartilage tissue. However, there are several different types of growth factors, and little has previously been known about which growth factors may be most beneficial for help stem cells differentiate in a way that supports cartilage.
New research published in Stem Cell Reviews has addressed this issue by looking specifically at how four specific growth factors affect differentiation of mesenchymal stem cells – and particularly – how they affect chondrogenic differentiation. The four growth factors explored in this study were: transforming growth factor beta 1 (TGF-β1), bone morphogenetic protein 2 (BMP2), parathyroid hormone-related protein (PTHrP), and fibroblast growth factor 2 (FGF2).
The scientists used methods of analyzing the levels of growth factors as well as the extent of collagen content on days 16, 23, and 30 after implementing growth factor programs. The results showed that TGF-β1 and BMP-2, when used in combination, increased short-term collagen content and other indicators of well-maintained cartilage. When PTHrP or FGF2 was applied, the overall impact of TGF-β1 and BMP-2 on cartilage tissue was initially decreased. Nonetheless, successive applications of both PTHrP and FGF2 helped to maintain the effects of TGF-β1 and BMP-2.
These results help to clarify the ways in which growth factors can be used to improve the ability of bone marrow derived mesenchymal stem cells to differentiate into cells that are viable for supporting cartilage. The specific outcomes provide critical information that can help with protocols for chondrogenic differentiation of stem cells. Future research will likely build on these findings to help scientists and clinicians better understand the best formulas for how to use growth factors to achieve desired results with stem cells.