GPR40 agonist inhibits NLRP3 inflammasome activation via modulation of nuclear factor-ΚB and sarco/endoplasmic reticulum Ca2+-ATPase

The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome is a multi-protein intracellular complex that activates proinflammatory cytokines, including interleukin (IL)-1 beta and IL-18. Inflammasome activation is related to metabolic inflammation, such as the progression of non-alcoholic steatohepatitis. Fasiglifam (TAK875), a selective G-protein coupled receptor 40 (GPR40) agonist with high affinity, significantly improves glucose-dependent insulin secretion and weight gain without hypoglycemia. Interestingly, we found that two GPR40 agonists, TAK875 and AMG1638, suppressed activation of the NLRP3 inflammasome in bone marrow-derived macrophages (BMDMs). TAK875 inhibited inflammasome activation by blocking formation of apoptosis-associated speck-like protein containing a CARD (ASC), an inflammasome component. TAK875 also suppressed NLRP3 inflammasome-induced pyroptosis of BMDMs. Moreover, nuclear factor-kappa B (NF-kappa B)dependent priming of the NLRP3 inflammasome was partially inhibited by TAK875 and AMG1638. The intracellular Ca2+ increase caused by ATP, nigericin (pore-forming toxin), or endoplasmic reticulum stress activates the NLRP3 inflammasome. Pre-exposure of BMDMs to TAK875 suppressed the ATP-induced intracellular Ca2+ increase, which was reversed by thapsigargin, a sarco/endoplasmic reticulum Ca2+-ATPase inhibitor. Oral administration of mice with TAK875 suppressed the increase in serum IL-1 beta in mice treated with lipopolysaccharide/D-galactosamine in vivo. These findings indicate that the free fatty acid-sensing GPR40 plays a key role in the NLRP3 inflammasome pathway.

Automated summary

Activation of the NLRP3 inflammasome is related to metabolic inflammation and can be suppressed by inhibiting the GPR40. TAK875 inhibits NLRP3 inflammasome activation by blocking the formation of the inflammasome component ASC. This suggests that GPR40 plays a key role in the NLRP3 inflammasome pathway.