Table 1.
Main mechanisms of lncRNAs expressed in macrophages during development and polarization
| Phases | Positive regulated | Mechanisms and models | Refs | Negative regulated | Mechanisms and models | Refs |
|---|---|---|---|---|---|---|
| Monocyte/macrophage differentiation | lnc‐MC | Act as miR‐199a‐5p sponge, releases it suppressor, THP‐1, HL‐60 cells and CD34+ HSPCs | 45, 46 | ‐ | ||
| M1‐like macrophages induced by inflammatory response | lncRNA‐Nfkb2, lncRNA‐Rel | Unknown, BMDMs | 57 | lncRNA Lethe | Keep p65 subunit away from DNA and inhibit inflammatory genes expression. NOX2 expression and ROS production, RAW264.7cells | 71 |
| AS‐IL1α | Recruit RNPII to the IL‐1α promoter, and elevate H3K9, BMDMs | 58 | lincRNA‐p21 | Sequester p65 mRNA and attenuate the translation of p65, human Jurkat T cell and THP‐1 monocyte lines | 72 | |
| lncRNA cox‐2(PACER) | Interacte with the p50/p50 homodimeric and act in cis‐ as a decoy to activate the promoter of cox‐2, human and mouse macrophages | 49, 59 | lnc‐IL7R | Enhance trimethylation of H3K27, lead to transcriptional silence, THP‐1 | 73 | |
| IL1β‐eRNA, IL1β‐RBT46 | Act as eRNAs to promote the expression of IL1‐β and CXCL8, THP‐1 | 60 | lincRNA THRIL | Interact with hnRNPL at the promoter of Tnfα to make sure the expression in dose control, human macrophages | 74, 75 | |
| lincRNA‐Tnfaip3 | Interact with the HMGB1 protein and facilitate Hmgb1‐associated histone modification, murine macrophages | 61, 62 | lncRNA SeT | Attenuate the stability of Tnfα mRNA levels, murine macrophages | 20 | |
| lncRNA‐CCL2 | Suppress histone deacetylase Sirtuin‐1, sepsis mice and LPS‐ stimulated macro phages | 64 | NKILA | Modify the phosphorylation motifs of IĸBα to block its degradation, breast cancer cell lines | 77 | |
| lncRNA FIRRE | Interact with hnRNPU and enhance stability of several inflammatory mRNAs, human macrophages and intestinal epithelial cells | 65 | lincRNA‐EPS | Function as a scaffold to bind hnRNPL, BMDMs | 78 | |
| lncRNA SNHG16 | Act as a ceRNA to up‐regulate TLR4 by down‐regulating the miR‐15a/16 cluster, RAW264.7 cells | 66 | MALAT1 | Interact with NF‐κB in the nucleus, keep it away from DNA and decrease inflammatory cytokines, THP‐1, RAW264.7 cells | 79 | |
| lincRNA‐Cox2 | Assemble into SWI/SNF complex; affecting IκBα degradation in the cytoplasm; interact with hnRNP‐A2/B1 and hnRNP‐A/B to suppress inflammation; promote recruitment of Mi‐2/NuRD repressor complex, which led to increased H3K27 dimethylation at Il12b promoter, BMDMs | 67, 68, 69, 70 | MacORIS | A repressor of IFN‐γ signalling, human THP‐1 macrophages | 81 | |
| lncRNA MALAT1 | Suppression of inflammatory responses by up‐regulating miR‐146a, murine alveolar macrophage cell line MH‐S | 80 | ||||
| M2‐like macrophages | lncRNA Mirt2 | Inhibit TRAF6 oligomerization and ubiquitination, RAW264.7 cells | 53 | ‐ | ||
| HOTTIP | Unknown, endotoxin‐tolerized macrophages | 50 | ‐ | |||
| lncRNA KCNQ1OT1 | Function as a miR‐21a‐5p decoy to up‐regulate IL‐10, PMMA‐induced BMDMs. | 83, 84 | ‐ | |||
| M1/M2 switch | lncRNA TCONS_00019715 | Decrease when M1 type is converted to M2, THP‐1, MDMs | 85 | PAK1 | Be helpful to M1 macrophage polarization, THP‐1, MDMs | 85 |
Abbreviations: BMDMs, bone marrow‐derived macrophages; H3K9, acetylation of histone H3 at lysine 9; HMGB1, high‐mobility group box 1 protein; hnRNPU, heterogeneous nuclear ribonucleoprotein; MDMs, monocyte‐derived macrophages; Mi‐2/NuRD, Mi‐2/nucleosome remodelling and deacetylase; NOX2, NADPH oxidase 2; PMMA, polymethyl methacrylate; ROS, reactive oxygen species; SWI/SNF, SWItch/Sucrose Non‐Fermentable; TRAF6, TNF receptor‐associated factor 6.