Biological Characteristics and Osteogenic Differentiation of Ovine Bone Marrow Derived Mesenchymal Stem Cells Stimulated with FGF-2 and BMP-2

Abstract

Cell-based therapies using mesenchymal stem cells (MSCs) are a promising tool in bone tissue engineering. Bone regeneration with MSCs involves a series of molecular processes leading to the activation of the osteoinductive cascade supported by bioactive factors, including fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 (BMP-2). In this study, we examined the biological characteristics and osteogenic differentiation potential of sheep bone marrow MSCs (BM-MSCs) treated with 20 ng/mL of FGF-2 and 100 ng/mL BMP-2 in vitro. The biological properties of osteogenic-induced BM-MSCs were investigated by assessing their morphology, proliferation, phenotype, and cytokine secretory profile. The osteogenic differentiation was characterized by Alizarin Red S staining, immunofluorescent staining of osteocalcin and collagen type I, and expression levels of genetic markers of osteogenesis. The results demonstrated that BM-MSCs treated with FGF-2 and BMP-2 maintained their primary MSC properties and improved their osteogenic differentiation capacity, as confirmed by increased expression of osteocalcin and collagen type I and upregulation of osteogenic-related gene markers BMP-2, Runx2, osterix, collagen type I, osteocalcin, and osteopontin. Furthermore, sheep BM-MSCs produced a variety of bioactive factors involved in osteogenesis, and supplementation of the culture medium with FGF-2 and BMP-2 affected the secretome profile of the cells. The results suggest that sheep osteogenic-induced BM-MSCs may be used as a cellular therapy to study bone repair in the preclinical large animal model.

Mesenchymal Stem Cells, Bioactive Factors, and Scaffolds in Bone Repair: From Research Perspectives to Clinical Practice

“…In particular, the BMP signaling pathway plays a crucial role in the differentiation of MSCs into the osteochondroprogenitor cells [53], after which they allow the differentiated osteoblasts to secrete the bone formatting matrix [54]. Moreover, BMPs have been shown to increase the expression of osteogenic markers in MSCs, including the early osteogenic markers alkaline phosphatase (Alp), Runtrelated transcription factor 2 (Runx2), osterix (Osx), and type I collagen (ColI) and the late markers osteopontin (Opn) and osteocalcin (Ocl) [53,[55][56][57]. Currently, BMP-2 (Medtronic) and BMP-7 (Stryker Biotech) are approved by the Food and Drug Administration (FDA) and available for clinical use in a recombinant form for bone fracture treatment and intervertebral disk regeneration enhancement [57].…”

“…They can stimulate osteoblast proliferation, promote differentiation into the osteogenic cell lineage, as well as induce angiogenesis [59]. Studies showed that FGF-2 and BMP-2 could act synergistically in bone regeneration, enhancing the effectiveness of bone formation [56,60,61].…”

The Potential of FGF-2 in Craniofacial Bone Tissue Engineering: A Review

“…The combination of FGF-2 and BMP-2 has already been tested at various concentrations and kinetics actions. A recent in vitro study suggests that sheep BMSCs supplemented with 20 ng/mL of FGF-2 and 100 ng/mL of BMP-2 may be a feasible cellular therapy for bone regeneration [233]. In vivo, the association of 10 µg of FGF-2 and 10 µg of BMP-2 in transfected human MSCs yielded a significantly increased bone regeneration of critical size calvarial defects of nude mice [234].…”

A Dual-Factor Releasing Hydrogel for Rotator Cuff Injury Repair

“…The most abundant fibroblast growth factors in normal adult tissues are FGF-1 and FGF-2. FGF-2 has a stronger mitotic promoting effect (Marquez et al, 2017;Gromolak et al, 2020;Sedlar et al, 2021), and can effectively promote the proliferation of stem cells in the process of tendon repair (Ide et al, 2009;Tokunaga et al, 2015;Guo et al, 2020). Previous reports have proved the effect of FGF-2 on the regeneration of tendons and other soft tissues (Tokunaga et al, 2015;Zhao et al, 2019).…”