Equine suspensory ligament and tendon explants cultured with platelet-rich gel supernatants release different anti-inflammatory and anabolic mediators.

This research paper investigates how certain supernatants influence the release of different anti-inflammatory and anabolic mediators in horse suspensory ligament and tendon explants. It was observed that leukocyte-reduced platelet-rich gel supernatants (Lr-PRGS) can effectively reduce certain inflammatory cytokines while promoting the release of certain others, potentially providing therapeutic benefits.

Experimental Setup

• The subjects of the study were suspensory ligament explants (SLEs) and tendon explants (TEs) from six horses.
• The explants were independently incubated for 48 hours with two types of supernatants, leukocyte-reduced platelet-rich-gel supernatant (Lr-PRGS) and leukocyte-reduced plasma supernatant (Lr-PL), and at two different concentrations (25% and 50%).

Methodology

• Samples were collected from the incubated tissues at the 1-hour and 48-hour marks for testing.
• An Elisa determination was conducted on interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), IL-1 receptor antagonist (IL-1ra), platelet-derived growth factor isoform BB (PDGF-BB), transforming growth factor beta-1(TGF-β, and hyaluronic acid (HA).

Findings

• Lr-PRGS at 50% concentration induced significantly less IL-1β release than other hemoderivatives in both tissues.
• Both Lr-PRGS and 25% Lr-PL at 48 hours induced higher TNF-α concentrations in SLEs compared to TEs.
• Both concentrations of Lr-PRGS induced significantly higher IL-4 concentrations in SLEs compared to TEs.
• There was no significant difference in IL-1ra release between tissues. However, this cytokine’s release was significantly higher in tissue explants cultured with both concentrations of Lr-PRGS.
• HA concentration was lower in tissue explants cultured with all hemoderivatives at both concentrations compared to the control group.

Conclusions

• The positive impacts observed for ligaments and tendons treated with Lr-PRGS could be due to the inhibition of IL-1β release and increased release of IL-4 and IL-1ra.
• Furthermore, PDGF-BB could potentially mediate the release of anti-inflammatory cytokines in SLEs and TEs incubated with Lr-PRGS.