MicroRNAs: New Regulators of Toll-Like Receptor Signalling Pathways

Table 1

miRNAs regulated by TLRs.

miRNA	TLRs	Signalling molecules	Transcription factors/cofactors	Cell types	Stimulus	Reference
Upregulated
miR-146a	TLR2, TLR3,; TLR4, TLR5	MyD88	NF-κB (P65)	THP1 cells, BMDMs, T cells, neural cells, MΦ, DCs, epithelial cells, PMN	LPS, TNF-α, IL-1β, LMP1, H2O2, VSV, RIG-I	[19–35]
miR-155	TLR2, TLR3,; TLR4, TLR9	MyD88, TRIF, KSRP	AP-1 (Fos/Jun), NF-κB (P65/P50)	BMDMs, THP1 cells, DCs, monocytes, MΦ, Treg cells	LPS, LMP1, TNF-α, KSHV, H. pylori, IFN-β, oxidized LDL, alcohol	[19, 28, 30, 33, 34, 36–48]
miR-132	TLR2, TLR4, TLR9	ND	cREB	THP1 cells, splenocytes, MΦ, monocytes, BMDMs,	KSHV	[19, 49–51]
miR-223	TLR4	ND	ND	Inflamed lung tissue, DCs	ND	[19, 38, 52–56]
miR-147	TLR2, TLR3, TLR4	MyD88, TRIF	NF-κB, IRF3	BMDMs, RAW264.7 cells, THP1 cells, alveolar MΦ	ND	[57]
miR-9	TLR2, TLR4,; TLR7, TLR8	MyD88	NF-κB	Monocytes, granulocytes, MΦ, PMN, biliary epithelial cells	LPS, TNF-α, IL-1β	[10, 58]
miR-27b	TLR4	ND	NF-κB (P65)	MΦ	LPS, C. parvum	[59–61]
let-7e	TLR4	AKT1	NF-κB	Peritoneal MΦ	ND	[62]
miR-21	TLR4	MyD88, TRIF	NF-κB (P65/P50); AP-1 (Fos/Jun)	RAW264.7 cells, BMDMs, B cells, PBMCs, H69 cholangiocytes, biliary epithelial cells, gastric and breast cancer cell line, promyelocytic leukemia cell line	LPS, LMP1, nicotine,; C. parvum, PMA; ectopic expression of HER2/neu	[23, 52, 60, 61, 63–68]
miR-125b	TLR4	ND	ND	Biliary epithelial cells, LPS-tolerized THP1 cells, fibroblast-like synoviocytes, H69 cholangiocytes	LPS, C. parvum	[61, 69]
miR-16	ND	ND	NF-κB (P65/P50)	Gastric cancer cells	Nicotine	[10, 64]
miR-23b	ND	ND	NF-κB (P65)	Biliary epithelial cells	LPS, C. parvum	[10, 60, 61]
miR-30b	ND	ND	NF-κB (P65)	Biliary epithelial cells	LPS, C. parvum	[10, 60, 61]
miR-301a	ND	ND	NF-κB (P65/P50)	Pancreatic cancer cells	TNF-α	[10, 70]
miR-212	ND	ND			KSHV, EtOH	[50]
miR-146b	ND	ND	AP-1 (Fos)	Glioblastoma cells, ovarian cancer cells	Platelet-derived growth factor	[71]
Downregulated
let-7i	TLR4	ND	NF-κB, C/EBPβ	H69 cholangiocytes	LPS, C. parvum	[72–75]
miR-98	TLR4	ND		H69 cholangiocytes	C. parvum	[75]
miR-125b	TLR4	AKT1	NF-κB	Splenocytes, BMDMs, DCs, RAW264.7 cells, macrophages	ND	[38, 40, 62]
miR-29b	ND	ND	NF-κB (P65), YY1, SP1, HDAC3,; HDAC1	Myoblast cell, acute myeloid leukemia cells	TNF-α	[76, 77]

MyD88: myeloid differentiation primary-response protein 88; BMDM: bone marrow-derived macrophage; PMN: polymorphonuclear neutrophil; LMP1: latent membrane protein 1; RIG-I: retinoic acid-inducible gene-I; VSV: vesicular stomatitis virus; TRIF: TIR domain-containing adaptor protein inducing IFN-β (also known as TICAM1, the TIR domain-containing adapter molecule 1); KSRP: KH-type splicing regulatory protein; JNK: JUN N-terminal kinase; C/EBPβ: CCAAT/enhancer-binding protein-β; KSHV: Kaposi’s sarcoma herpesvirus; LDL: low-density lipoprotein; Treg cell: regulatory T cell; C. parvum: Cryptosporidium parvum; YY1: Yin Yang 1; SP1: specificity protein 1; HDAC3: histone deacetylase 3; HDAC1: histone deacetylase 1; ND: not determined.