Ubiquitin-Specific Protease 2 Modulates the Lipopolysaccharide-Elicited Expression of Proinflammatory Cytokines in Macrophage-like HL-60 Cells
The isopeptidase region of USP2A is required for the downregulation of cytokine expression in macrophage-like cells. Wild-type and isopeptidase-deficient USP2A mutants were overexpressed in USP2KD cells. Cells were treated with PMA (30 nM; 1 d) and then stimulated with LPS (2.5 μg/mL) for (a, b) 4 h or (c) 12 h. Transcripts for (a) USP2 variants and (b) cytokines were assessed by qRT-PCR. Data were normalized according to HPRT-1 transcript levels. (c) IL-6 concentration in the supernatant was determined by ELISA. Data are presented as means ± SD of (a, b) six or (c) eight samples. Mock, USP2KD cells with a mock vector; AR, USP2KD cells with a USP2A expression construct; C276AR, USP2KD cells with an isopeptidase-deficient USP2A mutant expression construct. versus mock-transfected control cells; § versus USP2AR cells.