Purine analogues bearing a nitrate ester motif were previously discovered as cardioprotective and anti-inflammatory agents, but the anti-inflammatory mechanism remains to be established. We therefore investigated the anti-inflammatory effect of two purine analogues, MK118 bearing a nitrate ester moiety and the methyl-substituted analogue MK196 in Aortic Smooth Muscle Cells (AoSMCs), with emphasis on IL-1β release. The AoSMCs were stimulated with LPS with or without purine analogue, followed by ELISA, Olink proteomics, Western blot and real time PCR of NLRP3 inflammasome components. Both purine analogues inhibited the release of proteins involved in inflammation, such as TRAIL, CCL4, CSF1 and IL-1β in AoSMCs, as well as intracellular gene and protein expression of IL-1β and NLRP3 inflammasome components. MK196, but not MK118, also inhibited the LPS-induced release of IL-7, CXCL10, PD-L1, FLT3L and CCL20. We also showed that MK118 and possibly MK196 act via inhibition of JAKs. In silico studies showed that the purine moiety is a competent hinge binding motif and that the purine-piperazine scaffold is well accommodated in the lipophilic groove of JAK1-3. Both compounds establish interactions with catalytic amino acids in the active site of JAK1-3 and the terminal nitrate ester of MK118 was revealed as a promising pharmacophore. Our data suggest that MK118 and MK196 inhibit the release of proinflammatory proteins in AoSMCs, and targets JAK1-3 activation. Purine analogues also inhibit the expression of NLRP3 inflammasome genes and proteins and may in the future be evaluated for anti-inflammatory aspects on inflammatory diseases.
|Number of pages||10|
|Journal||European Journal of Pharmacology|
|Early online date||2 Jul 2022|
|Publication status||Published - 15 Aug 2022|
Bibliographical noteCopyright © 2022 The Authors. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
This work was supported by grants from The Knowledge Foundation HOG2017 ¨ #20170191 (PI Karin Frans´en); The Knowledge Foundation HOG2019 ¨ #20190088 (PI Karin Frans´en); Orebro ¨ University, Faculty of Medicine and Health #2019-06-13 (PI Karin Frans´en). Dimitra Pournara was supported by Alexander S Onassis Public Benefit Foundation fellowship, PI Maria Koufaki.
- Purine analogue
- NLRP3 inflammasome
- JAK inhibitor