PMID- 36467056
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20221206
IS  - 1663-9812 (Print)
IS  - 1663-9812 (Electronic)
IS  - 1663-9812 (Linking)
VI  - 13
DP  - 2022
TI  - Protein phosphatase 2A regulates xanthine oxidase-derived ROS production in 
      macrophages and influx of inflammatory monocytes in a murine gout model.
PG  - 1033520
LID - 10.3389/fphar.2022.1033520 [doi]
LID - 1033520
AB  - Background: Gout is a common arthritis, due to deposition of monosodium urate 
      (MSU) crystals which results in IL-1beta secretion by tissue-resident macrophages. 
      Xanthine oxidase (XO) catalyzes uric acid (UA) production and in the process, 
      reactive oxygen species (ROS) are generated which contributes to NLRP3 
      inflammasome activation. Protein phosphatase 2A (PP2A) may be involved in 
      regulating inflammatory pathways in macrophages. The objective of this study was 
      to investigate whether PP2A regulates gout inflammation, mediated by XO activity 
      modulation. We studied UA and ROS generations in MSU stimulated murine bone 
      marrow derived macrophages (BMDMs) in response to fingolimod phosphate, a PP2A 
      activator, and compared its anti-inflammatory efficacy to that of an XO 
      inhibitor, febuxostat. Methods: BMDMs were stimulated with MSU, GM-CSF/IL-1beta or 
      nigericin +/- fingolimod (2.5 muM) or febuxostat (200 muM) and UA levels, ROS, XO, 
      and PP2A activities, Xdh (XO) expression and secreted IL-1beta levels were 
      determined. PP2A activity and IL-1beta in MSU stimulated BMDMs +/- N-acetylcysteine 
      (NAC) (10 muM) +/- okadaic acid (a PP2A inhibitor) were also determined. M1 
      polarization of BMDMs in response to MSU +/- fingolimod treatment was assessed by a 
      combination of iNOS expression and multiplex cytokine assay. The in vivo efficacy 
      of fingolimod was assessed in a murine peritoneal model of acute gout where 
      peritoneal lavages were studied for pro-inflammatory classical monocytes (CMs), 
      anti-inflammatory nonclassical monocytes (NCMs) and neutrophils by flow cytometry 
      and IL-1beta by ELISA. Results: Fingolimod reduced intracellular and secreted UA 
      levels (p < 0.05), Xdh expression (p < 0.001), XO activity (p < 0.001), ROS 
      generation (p < 0.0001) and IL-1beta secretion (p < 0.0001), whereas febuxostat 
      enhanced PP2A activity (p < 0.05). NAC treatment enhanced PP2A activity and 
      reduced XO activity and PP2A restoration mediated NAC's efficacy as co-treatment 
      with okadaic acid increased IL-1beta secretion (p < 0.05). Nigericin activated 
      caspase-1 and reduced PP2A activity (p < 0.001) and fingolimod reduced caspase-1 
      activity in BMDMs (p < 0.001). Fingolimod reduced iNOS expression (p < 0.0001) 
      and secretion of IL-6 and TNF-alpha (p < 0.05). Fingolimod reduced CMs (p < 0.0001), 
      neutrophil (p < 0.001) and IL-1beta (p < 0.05) lavage levels while increasing NCMs 
      (p < 0.001). Conclusion: Macrophage PP2A is inactivated in acute gout by ROS and 
      a PP2A activator exhibited a broad anti-inflammatory effect in acute gout in 
      vitro and in vivo.
CI  - Copyright (c) 2022 Elsayed and Elsaid.
FAU - Elsayed, Sandy
AU  - Elsayed S
AD  - Department of Biomedical and Pharmaceutical Sciences, Chapman University School 
      of Pharmacy, Irvine, CA, United States.
FAU - Elsaid, Khaled A
AU  - Elsaid KA
AD  - Department of Biomedical and Pharmaceutical Sciences, Chapman University School 
      of Pharmacy, Irvine, CA, United States.
LA  - eng
PT  - Journal Article
DEP - 20221117
PL  - Switzerland
TA  - Front Pharmacol
JT  - Frontiers in pharmacology
JID - 101548923
PMC - PMC9712728
OTO - NOTNLM
OT  - fingolimod (FTY-720)
OT  - gout
OT  - macrophages
OT  - protein phosphatase 2a
OT  - xanthine oxidase
COIS- The authors declare that the research was conducted in the absence of any 
      commercial or financial relationships that could be construed as a potential 
      conflict of interest.
EDAT- 2022/12/06 06:00
MHDA- 2022/12/06 06:01
PMCR- 2022/11/17
CRDT- 2022/12/05 04:17
PHST- 2022/08/31 00:00 [received]
PHST- 2022/11/07 00:00 [accepted]
PHST- 2022/12/05 04:17 [entrez]
PHST- 2022/12/06 06:00 [pubmed]
PHST- 2022/12/06 06:01 [medline]
PHST- 2022/11/17 00:00 [pmc-release]
AID - 1033520 [pii]
AID - 10.3389/fphar.2022.1033520 [doi]
PST - epublish
SO  - Front Pharmacol. 2022 Nov 17;13:1033520. doi: 10.3389/fphar.2022.1033520. 
      eCollection 2022.