Proliferation and differentiation of human tenocytes in response to platelet rich plasma: an in vitro and in vivo study

A review of modern management of lateral epicondylitis

Lateral epicondylitis, or tennis elbow, is the most common cause of elbow pain. This degenerative condition can manifest as an acute process lasting < 3 months or a chronic process often refractory to treatment. Symptom resolution occurs in 70% to 80% of patients within the first year. A "watch-and-wait" approach can be an appropriate treatment option, although physical therapy has been shown to be an effective first-line therapy. Corticosteroids, while providing relief of pain in the acute setting, may be detrimental to recovery in the long term. Platelet-rich plasma injections, although recently well publicized, have not been proven by well-controlled clinical trials to be effective therapy. For patients with symptoms refractory to conservative management, surgical intervention has shown to be a successful treatment modality.

Characterization of the cytokine profile of platelet rich plasma (PRP) and PRP-induced cell proliferation and migration: Upregulation of matrix metalloproteinase-1 and -9 in HaCaT cells

Background

The underlying rationale of platelet rich plasma (PRP) therapy is that an injection of concentrated PRP at the site of injury may promote tissue repair via cytokine release from platelets. The molecular mechanisms of PRP therapy in the skin wound healing process are not well understood at present, and would benefit from clarification.

Methods

PRP was stimulated with angonists for 5 min, and cytokine profile analysis was performed. To investigate the wound healing activity of PRP, cell proliferation and migration analyses were performed in skin cells. The effects of PRP were analyzed on the expression and activity of matrix metalloproteinase (MMP)-1, -2, -9, and the activation of transcription factors.

Results

Thrombin was found to be a strong stimulator of PRP activation to release growth factors and chemokines. PRP induced cell proliferation and migration in HUVECs, HaCaT cells, and HDFs, as well as MMP-1and MMP-9 expression in HaCaT cells, but PRP did not have a significant effect on the expression or activity of MMPs in HDFs. The transcription factors, including signal transducer and activator of transcription-3 (STAT-3) were found to be phosphorylated following PRP treatment in HaCaT cells.

Conclusion

In this study, we have identified the cytokine profile of activated PRP after agonist stimulation. We have shown that PRP plays an active role in promoting the proliferation and migration of skin cells via the regulation of MMPs, and this may be applicable to the future development of PRP therapeutics to enhance skin wound healing.