Platelet-Derived Growth Factor-BB Promotes Proliferation and Osteogenic Differentiation of Rat Bone Marrow Mesenchymal Stem Cells

Abstract

Background: Previous research has indicated that platelet-rich plasma (PRP) promotes fracture healing and aids in the treatment of nonunion. A key component of PRP, platelet-derived growth factor BB (PDGF-BB), may play a crucial role in PRP, enhancing the biological functions of bone marrow mesenchymal stem cells (BMSCs). This study aims to investigate whether PDGF-BB is a key effector in PRP that promotes proliferation and osteogenic differentiation of BMSCs. Methods: Rat BMSCs were isolated and cultured, then expanded to the third generation for morphological observation. Flow cytometry analysis was conducted to assess the expression of CD44, CD29, CD45, and CD11b. The BMSCs were cultured under different conditions: the control group received only basic culture medium, while experimental groups received 10 ng/mL, 25 ng/mL, 50 ng/mL, 100 ng/mL, and 200 ng/mL PDGF-BB. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay at 1, 3, 5, 7, and 10 days. The optimal PDGF-BB concentration was determined based on the CCK-8 results for subsequent experiments. Blood was collected from the rats heart and used to prepare and activate platelet-rich plasma (PRP), which was then stored in liquid nitrogen for later use. According to the culture conditions for BMSCs, the experimental groups were as follows: a blank control group, a 10% PRP group, a 50 ng/mL PDGF-BB group, and a 10% PRP + 100 μM AG1295 [platelet-derived growth factor β receptor (PDGFR-β) inhibitor] group. Each experimental group was replicated three times. Cell proliferation was assessed using the CCK-8 assay, the cell cycle was analyzed using flow cytometry, and the expression of osteogenic differentiation markers was evaluated by Western blot. Results: The cell viability of BMSCs treated with 50 ng/mL of PDGF-BB for 5 days was significantly higher than that of other concentration groups and time points. CCK-8 and flow cytometry results indicated that compared to the control group, both 10% PRP and 50 ng/mL PDGF-BB significantly promoted BMSCs proliferation and increased the proportion of BMSCs in the S phase of the cell cycle. Western blot results demonstrated that compared to the control group, both 10% PRP and 50 ng/mL PDGF-BB significantly upregulated the protein expression levels of osteogenic differentiation markers. The use of the PDGFR-β inhibitor AG1295 markedly attenuated the proliferative and osteogenic effects of 10% PRP on BMSCs. Conclusions: A concentration of 50 ng/mL PDGF-BB significantly enhances the proliferation and osteogenic differentiation of rat BMSCs. PDGF-BB may play a key role in PRP, contributing to the enhancement of BMSCs proliferation and osteogenic differentiation.