Multiple ASC-dependent inflammasomes drive differential pro-inflammatory cytokine production in a mouse model of tendinopathy.

Inflammasomes are multiprotein complexes that regulate the bioactive production of IL-1β and IL-18, being implicated in the inflammatory response of different diseases. The inflammasome formed by the cytosolic sensor NLRP3 is highly promiscuous, as it could be activated by different pathogen- and sterile-signals. However, few models have studied the implication of NLRP3 in tissue damage-induced inflammation, particularly the implication of NLRP3 in tendinopathies. Here, we aimed to investigate the implication of NLRP3 in a mouse model of tendinopathy by collagenase degradation of the extracellular matrix in the Achilles' mice tendon. We found that NLRP3 was involved in the production of IL-1β, but another ASC-dependent inflammasome was required to produce IL-18 during sterile tissue damage. Our study suggests that in the immune response to extracellular matrix degradation different inflammasomes, probably expressed in different cell compartments, were able to differentially control IL-1β and IL-18 production in vivo. These results suggest the potential use of therapies targeting ASC as beneficial in the treatment of tendinopathies.