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Research article - Peer-reviewed, 2022

Conditioned serum in vitro treatment of chondrocyte pellets and osteoarthritic explants

Lofgren, Maria; Ekman, Stina; Ekholm, Josefine; Engstrom, Mona; Fjordbakk, Cathrine T.; Svala, Emilia; Forsstrom, Karin Holm; Lindahl, Anders; Skioldebrand, Eva


Background: Autologous conditioned serum (ACS) is used to treat osteoarthritis in horses, although its effects are not fully investigated.Objectives: To investigate the effects of equine serum and conditioned serum on chondrocytes stimulated with interleukin (IL)-1 beta and cartilage explants with mild osteoarthritis.Study design: In vitro experimental study.Methods: The effect of three different serum preparations (unincubated control [PS], serum incubated 24 h [PS24h] and serum incubated 24 h in ACS containers [PCS]) pooled from lame horses were tested in two in vitro models. IL-1 beta and IL-1 receptor antagonist (IL-1Ra) concentrations were measured in all sera. In model 1, chondrocyte pellet cultures were stimulated with IL-1 beta prior to treatment with the serum preparations for 2 and 48 h. Microarray, polymerase chain reaction, and matrix metallopeptidase-13 analyses were performed. In model 2, cartilage explants from horses with structural osteoarthritis were treated with PS or PCS on days 0, 6 and 12, or left untreated, and evaluated at day 24 using the OARSI grading scale for histological evaluation of articular cartilage.Results: The IL-1Ra concentration in PS24h and PCS was significantly higher than in PS. In model 1, inflammation- and cartilage matrix degradation-related genes were upregulated after 48 h in all treatment groups versus untreated controls. Cartilage matrix molecules, aggrecan and collagens, were downregulated in PS24h- and PCS-treated pellets versus untreated controls. Growth factor signalling genes were upregulated-FGF7 in all treatment groups, BMP2 in PS24h-, and INHBA in PCS-treated-compared with untreated controls. In model 2, the OARSI score at day 24 was not significantly different between treatment groups.Main limitations: Results from in vitro models cannot be directly translated to in vivo situations.Conclusions: In vitro treatment with conditioned serum did not alleviate IL-1 beta-induced responses in chondrocyte pellets or lead to morphological improvement in osteoarthritic cartilage explants.


autologous conditioned serum; horse; IL-1 receptor antagonist; inflammation; interleukin 1 beta; osteoarthritis

Published in

Equine Veterinary Journal
Publisher: WILEY

Authors' information

Löfgren, Maria
Swedish University of Agricultural Sciences, Department of Biomedical Science and Veterinary Public Health
Ekholm, Josefine
Sahlgrenska University Hospital
Engstrom, Mona
Sahlgrenska University Hospital
Fjordbakk, Cathrine T.
Norwegian University of Life Sciences
Svala, Emilia
Swedish University of Agricultural Sciences, Department of Biomedical Science and Veterinary Public Health
Svala, Emilia
Sahlgrenska University Hospital
Swedish University of Agricultural Sciences, University Animal Hospital
Lindahl, Anders
Sahlgrenska University Hospital
Skioldebrand, Eva (Skiöldebrand, Eva)
Sahlgrenska University Hospital

UKÄ Subject classification

Clinical Science

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