Conde, JavierScotece, MorenaAbella, VanessaLois, AnaLópez, VerónicaGarcía-Caballero Parada, TomásPino, JesúsGómez-Reino Carnota, Juan JesúsGómez, RodolfoLago Paz, María FranciscaGualillo, Oreste2020-05-112020-05-112015Conde, J., Scotece, M., Abella, V. et al. IL-36α: a novel cytokine involved in the catabolic and inflammatory response in chondrocytes. Sci Rep 5, 16674 (2015). https://doi.org/10.1038/srep166742045-2322http://hdl.handle.net/10347/22193Recent studies confer to IL-36α pro-inflammatory properties. However, little is known about the expression and function of IL-36α in cartilage. This study sought to analyze the expression of IL-36α in healthy and OA cartilage. Next, we determined the effects of recombinant IL-36α on catabolism and inflammation in chondrocytes. For completeness, part of the signaling pathway elicited by IL-36α was also explored. IL-36α expression was evaluated by immunohistochemistry and RT-qPCR. Expression of MMP-13, NOS2 and COX-2 was also determined in OA articular chondrocytes treated with recombinant IL-36α. IκB-α and P-p38 was explored by western blot. We observed a low constitutive expression of IL-36α in healthy human chondrocytes. However, OA chondrocytes likely expressed more IL-36α than healthy chondrocytes. In addition, immune cells infiltrated into the joint and PBMCs express higher levels of IL-36α in comparison to chondrocytes. OA chondrocytes, treated with IL-36α, showed significant increase in the expression of MMP-13, NOS2 and COX-2. Finally, IL-36α stimulated cells showed NFκB and p38 MAPK activated pathways. IL-36α acts as a pro-inflammatory cytokine at cartilage level, by increasing the expression of markers of inflammation and cartilage catabolism. Like other members of IL-1 family, IL-36α acts through the activation of NFκB and p38 MAPK pathway.eng© 2015 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/https://creativecommons.org/licenses/by/4.0/journal article10.1038/srep16674open access