Poster Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

IL-4 AND IL-10 ROLE IN HUMAN AND BOVINE INTERVERTEBRAL DISC DEGENERATION  (#23)

Paola Bermudez Lekerika 1 2 , Sofia Tseranidou 3 , Andrea Nüesch 4 , Katherine B. Crump 1 2 , Exarchos Kanelis 5 6 , Karin Wuertz 7 , Leonidas G. Alexopoulos 5 6 , Jérôme Noailly 3 , Christine Le Maitre 4 , Benjamin Gantenbein 1 8
  1. Tissue Engineering for Orthopaedics and Mechanobiology, Bone & Joint Program, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
  2. Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland
  3. BCN MedTech (Universitat Pompeu Fabra), Barcelona, Spain
  4. Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, United Kingdom
  5. School of Mechanical Engineering, National Technical University of Athens, Zografou, Athens, Greece
  6. Protavio Ltd, Agia Paraskevi, Athens, Greece
  7. Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, United States
  8. Inselspital, University of Bern and Department of Orthopedic Surgery & Traumatology, University of Bern, Bern, Switzerland

INTRODUCTION

Intervertebral disc (IVD) degeneration is a pathological process considered a major contributor to chronic back pain and leading cause of disability worldwide1. The IVD consists of an avascular proteoglycan-rich nucleus pulposus (NP) laterally constrained by the peripheral fibre-reinforced annulus fibrosus (AF), situated between two cartilage end plates (CEP) responsible for nutrient and oxygen transport2. During degeneration, progressive structural and biochemical changes occur including blood vessel and nerve ingrowth inside the IVD, leading to the cross-talk with immune system and promoting discogenic pain3. In the last decades, several cytokines have been studied in IVD to investigate their metabolic effect in the disc ECM. Particularly, IL-10 and IL-4 have been predicted as important anabolic factors in the IVD according to a regulatory network model based in silico approach4. Thus, we aim to investigate the potential presence and anabolic effect of IL-10 and IL-4 in human and bovine explants (ex vivo) under hypoxia (5% O2) after a catabolic induction.

 

METHODS

Bovine NP explants and human NP explants with IVD degeneration were harvested and cultured for five days under phenotype recovery media5 in 5% O2. Afterwards, explant cultures were i) cultured for two extra days and subsequently treated with 10 ng/ml IL-10 or IL-4 (single treatments) or ii) stimulated with 1 ng/ml IL-1β for two days and subsequently treated with 1 ng/ml IL-1β and 10 ng/ml IL-10 or IL-4 (combined treatments) under hypoxia environment. Finally, human and bovine explants were collected together with the culture media for downstream analysis of anabolic and catabolic gene expression and protein secretome analysis. Additionally, immunohistochemistry was used to determine the expression of IL-4 and IL-10 receptors in native human NP tissue. For statistical analysis, a nonparametric distribution was assumed and Kruskal–Wallis test followed by Dunn’s multiple comparisons test was performed in 3-4 human and bovine biological replicates each of them with 2-3 independent explant cultures.

 

RESULTS:

The presence of IL-4 and IL-10 receptors was confirmed in human NP tissue (Fig. 1A). Additionally, IL-4 single treatments induced a significant increase of proinflammatory mediators, including TNF protein secretion in human ex vivo system, while no significant differences were observed in the secretome between IL-10 single and combined treatments compared to control group (Fig. 1B). Moreover, IL-10 containing treatments showed an anti-catabolic and anti-inflamamtory effect at the gene level, as evidenced by a significant decreased in IL-8 gene expression compared to no treatment control (human explants) and in MMP3 gene expression compared to IL-1 treatment (bovine explants). However, IL-1and IL-10 combined treatment in both human and bovine explants showed a catabolic effect, with a decrease in ACAN gene expression (Fig. 1C).

 

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DISCUSSION:

Overall, IL-4 containing treatments promote human NP cell and explant catabolism at the secretome level in contrast to the previously reported anti-inflammatory performance of IL-4 6. Thus, a possible pleiotropic effect of IL-4 could occur depending on the IVD culture and environmental condition. In contrast, IL-10 containing treatments showed an anabolic effect in both human and bovine explants at the gene level, yet without protein evidence.

  1. 1. J. Hartvigsen et al (2018) The Lancet 391:2356-67.
  2. 2. P. Bermudez-Lekerika and K. Crump et al (2022) Front Cell Dev Biol 10:924692.
  3. 3. PPA. Vergroesen et al (2015) Osteoarthritis and Cartilage 23:1165-77
  4. 4. S. Tseranidou et al, EBS 2023 28th Congress, July 9-12, 2023, Maastricht, The Netherlands.
  5. 5. S. Basatvat et al (2023) JOR Spine 6:1238.
  6. 6. H. Kedong et al (2020) The Spine Journal 20:60−68.