Non-classical human monocytes are characterized by high-level expression of cytokines like TNF, but the mechanisms involved are elusive. We have identified miRNAs and CpG-methylation sites that are unique to non-classical monocytes, defined via CD14 and CD16 expression levels. For down-regulated miRNAs that are linked to up-regulated mRNAs the dominant gene ontology term was intracellular signal transduction. This included down-regulated miRNA-20a-5p and miRNA-106b-5p, which both are linked to increased mRNA for the TRIM8 signaling molecule. Methylation analysis revealed 16 hypo-methylated CpG sites upstream of 14 differentially increased mRNAs including 2 sites upstream of TRIM8. Consistent with a positive role in signal transduction, high TRIM8 levels went along with high basal TNF mRNA levels in non-classical monocytes. Since cytokine expression levels in monocytes strongly increase after stimulation with toll-like-receptor ligands, we have analyzed non-classical monocytes (defined via slan expression) after stimulation with lipopolysaccharide (LPS). LPS-stimulated cells continued to have low miRNA-20a and miRNA-106b and high TRIM8 mRNA levels and they showed a 10-fold increase in TNF mRNA. These data suggest that decreased miRNAs and CpG hypo-methylation is linked to enhanced expression of TRIM8 and that this can contribute to the increased TNF levels in non-classical human monocytes.

非经典人类单核细胞的特点是高水平表达细胞因子，如 TNF，但所涉及的机制尚不清楚。我们已经确定了非经典单核细胞特有的 miRNA 和 CpG 甲基化位点，通过 CD14 和 CD16 表达水平定义。对于与上调 mRNA 相关的下调 miRNA，显性基因本体术语是细胞内信号转导。这包括下调的 miRNA-20a-5p 和 miRNA-106b-5p，它们都与 TRIM8 信号分子的 mRNA 增加有关。甲基化分析揭示了 14 个差异增加的 mRNA 上游的 16 个低甲基化 CpG 位点，包括 TRIM8 上游的 2 个位点。与在信号转导中的积极作用一致，高 TRIM8 水平伴随着非经典单核细胞中高基础 TNF mRNA 水平。由于用 toll 样受体配体刺激后单核细胞中的细胞因子表达水平强烈增加，我们分析了用脂多糖 (LPS) 刺激后的非经典单核细胞（通过 slan 表达定义）。LPS 刺激的细胞继续具有较低的 miRNA-20a 和 miRNA-106b 以及较高的 TRIM8 mRNA 水平，并且它们的 TNF mRNA 增加了 10 倍。这些数据表明，减少的 miRNA 和 CpG 低甲基化与 TRIM8 的表达增强有关，这可能导致非经典人类单核细胞中 TNF 水平的增加。LPS 刺激的细胞继续具有较低的 miRNA-20a 和 miRNA-106b 以及较高的 TRIM8 mRNA 水平，并且它们的 TNF mRNA 增加了 10 倍。这些数据表明，减少的 miRNA 和 CpG 低甲基化与 TRIM8 的表达增强有关，这可能导致非经典人类单核细胞中 TNF 水平的增加。LPS 刺激的细胞继续具有较低的 miRNA-20a 和 miRNA-106b 以及较高的 TRIM8 mRNA 水平，并且它们的 TNF mRNA 增加了 10 倍。这些数据表明，减少的 miRNA 和 CpG 低甲基化与 TRIM8 的表达增强有关，这可能导致非经典人类单核细胞中 TNF 水平的增加。