PMID- 30189890 OWN - NLM STAT- MEDLINE DCOM- 20190718 LR - 20190816 IS - 1478-6362 (Electronic) IS - 1478-6354 (Print) IS - 1478-6354 (Linking) VI - 20 IP - 1 DP - 2018 Sep 6 TI - Arhalofenate acid inhibits monosodium urate crystal-induced inflammatory responses through activation of AMP-activated protein kinase (AMPK) signaling. PG - 204 LID - 10.1186/s13075-018-1699-4 [doi] LID - 204 AB - BACKGROUND: Arhalofenate acid, the active acid form of arhalofenate, is a non-agonist peroxisome proliferator-activated receptor gamma (PPARgamma) ligand, with uricosuric activity via URAT1 inhibition. Phase II studies revealed decreased acute arthritis flares in arhalofenate-treated gout compared with allopurinol alone. Hence, we investigated the anti-inflammatory effects and mechanisms of arhalofenate and its active acid form for responses to monosodium urate (MSU) crystals. METHODS: We assessed in-vivo responses to MSU crystals in murine subcutaneous air pouches and in-vitro responses in murine bone marrow-derived macrophages (BMDMs) by enzyme-linked immunosorbent assay (ELISA), SDS-PAGE/Western blot, immunostaining, and transmission electron microscopy analyses. RESULTS: Oral administration of arhalofenate (250 mg/kg) blunted total leukocyte ingress, neutrophil influx, and air pouch fluid interleukin (IL)-1beta, IL-6, and CXCL1 in response to MSU crystal injection (p < 0.05 for each). Arhalofenate acid (100 muM) attenuated MSU crystal-induced IL-1beta production in BMDMs via inhibition of NLRP3 inflammasome activation. In addition, arhalofenate acid dose-dependently increased activation (as assessed by phosphorylation) of AMP-activated protein kinase (AMPK). Studying AMPKalpha1 knockout mice, we elucidated that AMPK mediated the anti-inflammatory effects of arhalofenate acid. Moreover, arhalofenate acid attenuated the capacity of MSU crystals to suppress AMPK activity, regulated expression of multiple downstream AMPK targets that modulate mitochondrial function and oxidative stress, preserved intact mitochondrial cristae and volume density, and promoted anti-inflammatory autophagy flux in BMDMs. CONCLUSIONS: Arhalofenate acid is anti-inflammatory and acts via AMPK activation and its downstream signaling in macrophages. These effects likely contribute to a reduction of gout flares. FAU - McWherter, Charles AU - McWherter C AD - CymaBay Therapeutics, Inc., Newark, California, USA. FAU - Choi, Yun-Jung AU - Choi YJ AD - CymaBay Therapeutics, Inc., Newark, California, USA. FAU - Serrano, Ramon L AU - Serrano RL AD - VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA. AD - University of California San Diego, La Jolla, California, USA. FAU - Mahata, Sushil K AU - Mahata SK AD - VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA. AD - University of California San Diego, La Jolla, California, USA. FAU - Terkeltaub, Robert AU - Terkeltaub R AD - VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA. AD - University of California San Diego, La Jolla, California, USA. FAU - Liu-Bryan, Ru AU - Liu-Bryan R AUID- ORCID: 0000-0002-9611-8163 AD - VA San Diego Healthcare System, 111K, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA. ruliu@ucsd.edu. AD - University of California San Diego, La Jolla, California, USA. ruliu@ucsd.edu. LA - eng GR - I01 BX002234/BX/BLRD VA/United States GR - I01BX002234/BX/BLRD VA/United States GR - I01BX001660/BX/BLRD VA/United States GR - P50 AR060772-6/AR/NIAMS NIH HHS/United States GR - I01 BX001660/BX/BLRD VA/United States GR - P50 AR060772/AR/NIAMS NIH HHS/United States GR - I01 BX003934/BX/BLRD VA/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20180906 PL - England TA - Arthritis Res Ther JT - Arthritis research & therapy JID - 101154438 RN - 0 (Acetamides) RN - 0 (Inflammation Mediators) RN - 0 (Phenylacetates) RN - 1P01UJR9X1 (arhalofenate) RN - 268B43MJ25 (Uric Acid) RN - EC 2.7.11.31 (AMP-Activated Protein Kinases) SB - IM MH - AMP-Activated Protein Kinases/*metabolism MH - Acetamides/*pharmacology/therapeutic use MH - Animals MH - Bone Marrow Cells/drug effects/metabolism/pathology MH - Cells, Cultured MH - Inflammation/drug therapy/metabolism/pathology MH - Inflammation Mediators/antagonists & inhibitors/*metabolism MH - Mice MH - Mice, Inbred C57BL MH - Phenylacetates/*pharmacology/therapeutic use MH - Signal Transduction/*drug effects/physiology MH - Uric Acid/antagonists & inhibitors/*toxicity PMC - PMC6127987 OTO - NOTNLM OT - AMPK OT - Autophagy flux OT - Gout OT - Inflammation OT - Mitochondria COIS- ETHICS APPROVAL: The handing of mice and experimental procedures were in accordance with requirements of the Institutional Animal Care and Use Committee and this study was granted permission by the CymaBay Research Oversight Committee. CONSENT FOR PUBLICATION: Not applicable. COMPETING INTERESTS: RT has received research support jointly from Ardea/Astra-Zeneca and Ironwood, and has received payment as a consultant to SOBI, Selecta, and Horizon, and has a consulting agreement with CymaBay Therapeutics, Inc. RLB has received research funding from by CymaBay Therapeutics, Inc. The remaining authors declare that they have no competing interests. PUBLISHER'S NOTE: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. EDAT- 2018/09/08 06:00 MHDA- 2019/07/19 06:00 PMCR- 2018/09/06 CRDT- 2018/09/08 06:00 PHST- 2018/05/09 00:00 [received] PHST- 2018/08/14 00:00 [accepted] PHST- 2018/09/08 06:00 [entrez] PHST- 2018/09/08 06:00 [pubmed] PHST- 2019/07/19 06:00 [medline] PHST- 2018/09/06 00:00 [pmc-release] AID - 10.1186/s13075-018-1699-4 [pii] AID - 1699 [pii] AID - 10.1186/s13075-018-1699-4 [doi] PST - epublish SO - Arthritis Res Ther. 2018 Sep 6;20(1):204. doi: 10.1186/s13075-018-1699-4.