1. Academic Validation
  2. PRMT4 inhibitor TP-064 inhibits the pro-inflammatory macrophage lipopolysaccharide response in vitro and ex vivo and induces peritonitis-associated neutrophilia in vivo

PRMT4 inhibitor TP-064 inhibits the pro-inflammatory macrophage lipopolysaccharide response in vitro and ex vivo and induces peritonitis-associated neutrophilia in vivo

  • Biochim Biophys Acta Mol Basis Dis. 2021 Nov 1;1867(11):166212. doi: 10.1016/j.bbadis.2021.166212.
Yiheng Zhang 1 Miriam de Boer 2 Ezra J van der Wel 2 Miranda Van Eck 2 Menno Hoekstra 2
Affiliations

Affiliations

  • 1 Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands. Electronic address: y.zhang.43@lacdr.leidenuniv.nl.
  • 2 Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands.
Abstract

Previous in vitro studies have shown that protein arginine N-methyltransferase 4 (PRMT4) is a co-activator for an array of cellular activities, including NF-κB-regulated pro-inflammatory responses. Here we investigated the effect of PRMT4 Inhibitor TP-064 treatment on macrophage inflammation in vitro and in vivo. Exposure of RAW 264.7 monocyte/macrophages to TP-064 was associated with a significant decrease in the production of pro-inflammatory cytokines upon a lipopolysaccharide challenge. Similarly, thioglycollate-elicited peritoneal cells isolated from wildtype mice treated with TP-064 showed lowered mRNA expression levels and cytokine production of pro-inflammatory mediators interleukin (IL)-1β, IL-6, IL-12p40, and tumor necrosis factor-α in response to lipopolysaccharide exposure. However, TP-064-treated mice exhibited an ongoing pro-inflammatory peritonitis after 5 days of thioglycollate exposure, as evident from a shift in the peritoneal macrophage polarization state from an anti-inflammatory LY6ClowCD206hi to a pro-inflammatory LY6ChiCD206low phenotype. In addition, TP-064-treated mice accumulated (activated) neutrophils within the peritoneum as well as in the blood (7-fold higher; P < 0.001) and major organs such as kidney and liver, without apparent tissue toxicity. TP-064 treatment downregulated hepatic mRNA expression levels of the PRMT4 target genes glucose-6-phosphatase catalytic subunit (-50%, P < 0.05) and the cyclin-dependent kinases 2 (-50%, P < 0.05) and 4 (-30%, P < 0.05), suggesting a direct transcriptional effect of PRMT4 also in hepatocytes. In conclusion, we have shown that the PRMT4 Inhibitor TP-064 induces peritonitis-associated neutrophilia in vivo and inhibits the pro-inflammatory macrophage lipopolysaccharide response in vitro and ex vivo. Our findings suggest that TP-064 can possibly be applied as therapy in NF-κB-based inflammatory diseases.

Keywords

CARM1; Gene expression; LPS; Pro-inflammatory cytokines; Thioglycollate-induced peritonitis.

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