The Role of Growth Hormone in Mesenchymal Stem Cell Commitment

Abstract

Growth hormone (GH) is best known for its prominent role in promoting prepubertal growth and in regulating body composition and metabolism during adulthood. In recent years, the possible role of GH in the modulation of mesenchymal stem cell (MSC) commitment has gained interest. MSCs, characterized by active self-renewal and differentiation potential, express GH receptors. In MSCs derived from different adult tissues, GH induces an inhibition of adipogenic differentiation and favors MSC differentiation towards osteogenesis. This activity of GH indicates that regulation of body composition by GH has already started in the tissue progenitor cells. These findings have fostered research on possible uses of MSCs treated with GH in those pathologies, where a lack of or delays in bone repair occur. After an overview of GH activities, this review will focus on the research that has characterized GH's effects on MSCs and on preliminary studies on the possible application of GH in bone regenerative medicine.

Keywords: bone repair; cell differentiation; growth hormone; regenerative medicine.

Figure 1

Schematic representation of the main intracellular signaling pathways activated by the binding of growth hormone (GH) to its receptor (blue arrows: activation; red T-arrows: inhibition).

Figure 2

Schematic representation of antiadipogenic action of GH in human mesenchymal stem cells (MSCs) derived from trabecular bone (blue arrows indicate related effects).