IL-6 and TNF are Potential Inflammatory Biomarkers in Facioscapulohumeral Muscular Dystrophy

• Published in: Journal of neuromuscular diseases Vol. 11; no. 2; pp. 327 - 347
• Main Authors: Greco, Anna, Mul, Karlien, Jaeger, Martin H., dos Santos, Jéssica C., Koenen, Hans, de Jong, Leon, Mann, Ritse, Fütterer, Jurgen, Netea, Mihai G., Pruijn, Ger J.M., van Engelen, Baziel G.M., Joosten, Leo A.B.
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 05.03.2024; IOS Press BV; IOS Press
• Subjects: Biopsy; Cell activation; Cytokines; Inflammation; Interleukin 6; Magnetic resonance imaging; Monocyte chemoattractant protein 1; Monocytes; Muscular dystrophy; Myopathy; Pathology; Research Report; Therapeutic targets; Vascular endothelial growth factor; Facioscapulohumeral muscular dystrophy; inflammation; cytokines
• ISSN: 2214-3599; 2214-3602
• DOI: 10.3233/JND-230063

Background: FSHD is a highly prevalent inherited myopathy with a still poorly understood pathology. Objective: To investigate whether proinflammatory cytokines are associated with FSHD and which specific innate immune cells are involved in its pathology. Methods: First, we measured circulating cytokines in serum samples: IL-6 (FSHD, n = 150; HC, n = 98); TNF (FSHD, n = 150; HC, n = 59); IL-1α (FSHD, n = 150; HC, n = 66); IL-1β (FSHD, n = 150; HC, n = 98); MCP-1 (FSHD, n = 14; HC, n = 14); VEGF-A (FSHD, n = 14; HC, n = 14). Second, we tested trained immunity in monocytes (FSHD, n = 15; HC, n = 15) and NK cells (FSHD, n = 11; HC, n = 11). Next, we explored the cytokine production capacity of NK cells in response to different stimuli (FSHD, n = 39; HC, n = 22). Lastly, we evaluated the cytokine production of ex vivo stimulated MRI guided inflamed (TIRM+) and paired MRI guided non inflamed (TIRM–) muscle biopsies of 21 patients and of 8 HC muscle biopsies. Results: We included a total of 190 FSHD patients (N = 190, 48±14 years, 49% men) and of 135 HC (N = 135, 44±15 years, 47% men). We found that FSHD patients had higher concentrations of IL-6 and TNF measured (a) in the circulation, (b) after ex-vivo stimulation of NK cells, and (c) in muscle specimens. Besides, IL-6 circulating concentrations, as well as its production by NK cells and IL-6 content of FSHD muscle specimens, showed a mild correlation with disease duration, disease severity, and muscle weakness. Conclusion: These results show that IL-6 and TNF may contribute to FSHD pathology and suggest novel therapeutic targets. Additionally, the activation of NK cells in FSHD may be a novel pathway contributing to FSHD pathology.