The Effect of Autologous Protein Solution on the Inflammatory Cascade in Stimulated Equine Chondrocytes.

Renata L Linardi,Kyla F Ortved,Kaitlyn L Moss,Michael E Dodson,William J King

doi:10.3389/fvets.2019.00064

Renata L Linardi, Kyla F Ortved + Show 3 more

Open Access

https://doi.org/10.3389/fvets.2019.00064

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Abstract

Cartilage injury occurs commonly in equine athletes, often precipitating posttraumatic osteoarthritis (PTOA). Orthobiologics such as autologous conditioned serum (ACS) and autologous protein solution (APS) may be useful in decreasing posttraumatic inflammation, thereby preventing PTOA. The objective of this study was to quantify cytokine concentrations in ACS and APS and evaluate the protective effects of ACS and APS on inflamed chondrocytes cultured in vitro. We hypothesized that the combination of platelet-derived growth factors (PDGF) and anti-inflammatory cytokines present in APS would be superior in decreasing the inflammatory and catabolic cascade in inflamed chondrocytes when compared to ACS in which platelets are excluded from the preparation. Chondrocytes were isolated from the cartilage of femoral trochlear ridges of 6 horses and cultured in 12-well transwell plates. Treatment groups included: (1) control, (2) APS (Pro-Stride; Owl Manor), and (3) ACS (IRAP II; Arthrex). Each group was unstimulated or stimulated with IL-1β and TNF-α for 48 h. The concentration of IL-1β, IL-6, TNF-α, MMP-3, MMP-13, and IL-10 was quantified using a fluorescent bead-based multiplex assay. IL-1Ra concentration was quantified using ELISA. APS and ACS both had significantly increased concentrations of IL-1Ra without a concurrent increase in IL-1β concentration. After 48 h of culture, media from chondrocytes treated with APS contained significantly increased concentrations of IL-1Ra and IL-10. APS-treated cultures had increased concentrations of IL-6. Overall, APS effectively concentrated IL-1Ra without an incubation period and media from APS-treated chondrocytes had increased concentrations of chondroprotective (IL-1Ra and IL-10) and modulatory (IL-6) cytokines, which may be beneficial in the treatment of inflammatory conditions such as PTOA.

Highlights

Traumatic injury to articular cartilage occurs commonly in the equine athlete and, due to the poor intrinsic healing capabilities of cartilage, can lead to osteoarthritis (OA) [1, 2]
The concentration of other cytokines including IL-1β, IL-6, TNF-α, and IL-10 were similar in serum, autologous conditioned serum (ACS), and autologous protein solution (APS) (Figure 2)
Autologous protein solution, an orthobiologic that concentrates platelets and anti-inflammatory cytokines, has been shown to improve clinical symptoms associated with knee osteoarthritis in human patients [12, 13]

Summary

Introduction

Traumatic injury to articular cartilage occurs commonly in the equine athlete and, due to the poor intrinsic healing capabilities of cartilage, can lead to osteoarthritis (OA) [1, 2]. Posttraumatic inflammation occurs within the joint characterized by increased activity of catabolic cytokines and decreased activity of anabolic cytokines [3]. Uncontrolled inflammation leads to degradation of the extracellular matrix (ECM) and eventually, posttraumatic osteoarthritis (PTOA). Interleukin-1β (IL-1β) produced by inflamed chondrocytes and synoviocytes, is a central cytokine driving inflammation and leads to upregulation of degradative enzymes, including matrix metalloproteinases (MMPs) and aggrecanases, that actively degrade proteoglycans, and type II collagen in the ECM. Traditional methods for controlling joint inflammation and pain include administration of intraarticular corticosteroids and hyaluronic acid; more recently autologous blood products have been investigated as they aim to decrease inflammation while stimulating healing. The detrimental effects of long-term intra-articular corticosteroid administration can be avoided

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