Platelet Lysate Induces in Human Osteoblasts Resumption of Cell Proliferation and Activation of Pathways Relevant for Revascularization and Regeneration of Damaged Bone

Abstract

To understand the regenerative effect of platelet-released molecules in bone repair one should investigate the cascade of events involving the resident osteoblast population during the reconstructive process. Here the in vitro response of human osteoblasts to a platelet lysate (PL) stimulus is reported. Quiescent or very slow dividing osteoblasts showed a burst of proliferation after PL stimulation and returned to a none or very slow dividing condition when the PL was removed. PL stimulated osteoblasts maintained a differentiation capability in vitro and in vivo when tested in absence of PL. Since angiogenesis plays a crucial role in the bone healing process, we investigated in PL stimulated osteoblasts the activation of hypoxia-inducible factor 1-alpha (HIF-1α) and signal transducer and activator of transcription 3 (STAT3) pathways, involved in both angiogenesis and bone regeneration. We observed phosphorylation of STAT3 and a strong induction, nuclear translocation and DNA binding of HIF-1α. In agreement with the induction of HIF-1α an enhanced secretion of vascular endothelial growth factor (VEGF) occurred. The double effect of the PL on quiescent osteoblasts, i.e., resumption of proliferation and activation of pathways promoting both angiogenesis and bone formation, provides a rationale to the application of PL as therapeutic agent in post-traumatic bone repair.

Molecular Research on Platelet Activity in Health and Disease 2.0

“…Furthermore, platelets activate STAT3, thus stimulating endothelial cells involved in angiogenesis and osteogenesis processes. These results corroborate the finding that, in regenerative medicine, platelets activate quiescent osteoblasts, while stimulating angiogenesis [ 10 ].…”

Platelet-to-Lymphocyte Ratio as an Independent Factor Was Associated With the Severity of Ankylosing Spondylitis

“…Quiescent or very slowly dividing osteoblasts showed a burst of proliferation after platelet stimulation and returned to a non-dividing or very slowly dividing condition when platelets were removed. Besides, freeze-dried PRP induced osteoblast proliferation via platelet-derived growth factor receptor- The red text means that the p value was < 0.05. mediated signal transduction (15). These studies demonstrated that platelet were strongly associated with bone formation.…”

Ceramic Scaffolds in a Vacuum Suction Handle for Intraoperative Stromal Cell Enrichment

“…Although the content of platelet lysates is highly promising for regenerative approaches in translational orthopedics [ 32 ] and these systems are also non-invasive (i. v. punction), they leave the surgical site and do not penetrate porous bone substitutes as a vacuum system can. At the very least, most systems designed for bone regeneration are at a pre-clinical stage [ 33 ].…”