Inhibition of pro-inflammatory signalling in human primary macrophages by enhancing Arginase-2 via target site blockers
Ontology highlight
ABSTRACT: A favourable immunotherapeutic strategy in the treatment of chronic inflammatory disease, is to dampen the pro-inflammatory macrophage response and upregulate the anti-inflammatory macrophage response. Previous studies have shown that Arginase-2 (Arg2), a mitochondrial enzyme, is a key regulator of the macrophage anti-inflammatory response with an essential role in IL-10 signalling. Here we show that IL-10 in the presence of LPS increased Arg2 expression in human macrophages and peripheral blood mononuclear cells. Target site blockers (TSBs) (locked nucleic acid antisense oligonucleotides) specifically designed to target the 3’ UTR of Arg2 messenger RNA were used to inhibit binding of specific microRNAs thus enhancing Arg2 expression. Eleven Arg2-TSBs were screened and the TSB targeting miR-155 (TSB-155) and the TSB targeting miR-3202 (TSB-3202) were found to increase Arg2 expression in human macrophages resulting in decreased gene expression and cytokine production of TNF-α and CCL2. In addition, following TSB-3202 stimulation, there were statistically significant increases in the ‘M2-like’ macrophage marker, CD206; and CD16, associated with an IL-10 response, and a decrease in the ‘M1-like’ macrophage marker, HLA-DR, indicating a shift in the macrophage phenotype. Proteomic analysis demonstrated that multiple pro-inflammatory responsive proteins including Signal Transducer and Activator of Transcription 1 (STAT-1), Toll-like receptors, Signalling Lymphocytic Activation Molecule F7 (SLAMF7) and Interferon Induced Protein with Tetratricopeptide Repeats 3 (IFIT3), were downregulated by TSB-155 and TSB-3202 while Sequestomsome-1 (SQSTM1) was increased after treatment. In silico analysis of significantly dysregulated proteins predicted that TSB-3202 supressed several upstream pro-inflammatory regulators including STAT-1 and Interferon α2 (IFNA2) while enhancing anti-inflammatory associated interleukin 1 receptor antagonist (IL1RN) and STAT-3. Proteomic data was validated by confirming increased levels of SQSTM1, decreased levels of phosphoylated-STAT-1 and STAT-1, and downregulation of Ifit3 and Slamf7 by TSB treatment. In conclusion, upregulation of Arg2 protein by TSBs inhibits several pro-inflammatory signalling proteins resulting in reduced pro-inflammatory cytokine secretion, reduced ‘M1-like’ marker expression and enhanced ‘M2-like’ macrophage marker expression. Arg2 is a promising novel therapeutic target to modulate inflammatory signalling in macrophages.
INSTRUMENT(S): Q Exactive
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Blood Platelet, Macrophage
DISEASE(S): Multiple Sclerosis
SUBMITTER: Eugene Dillon
LAB HEAD: Claire McCoy
PROVIDER: PXD035018 | Pride | 2023-10-24
REPOSITORIES: Pride
ACCESS DATA