Table 1.

List of miRNAs that Are Differentially Expressed in Lung Diseases (COPD, asthma, lung cancer, IPF, and CF), with Their Respective Target Sites and Findings Listed Above

Lung Diseases	Specific miRNA	Expression Level	Target Site/Host Gene	Findings	References
COPD	miR-146a	high	COX-2	targets 3′ UTR of the Cox2 mRNA and suppresses the expression	1
	miR-149-3p	low	TLR-4, MyD88	reduced expression causes overexpression of TLR-4 and MyD88	2
	miR-145-5p	high	SMAD3, CFTR, SLC26A9	involved in Th2 response activation, blocks chloride ion channel	3, 4
	miR-199a-5p	low	Unfolded protein responses	intensification of the UPR	5
	miR-101 and miR-144	high	MKP-1, TGF-β signaling	induce inflammatory responses	6
	miR-15b	high	SMAD7	induces TGF-β signaling	7
Asthma	miR-126	high	TLRs	activation of inflammatory pathways	8
	miR-21	high	IL-12p35	modulates IL-12 expression and polarizes Th cells toward Th2 response	9
	miR-155 and miR-146a	high	transcription factor PU.1 and IL-4	contributes to immediate inflammation and allergic reactions	10
	miR-133a	low	RhoA	excessive bronchial smooth muscle (BSM) contraction	11
	miR-221 and miR-222	high	p21WAF1 and p27kip1	involved in mast cell activation and release several growth factors	12
	miR-106a	high	IL-10	increases pro-inflammatory cytokines release	13, 14
	miR-181	high	NF-κB	induces increased TCR sensitivity	15
	miR-19a	high	PI3K, JAK-STAT, NF-κB signaling	promotes allergic inflammatory phenotype	16, 17
Lung cancer	miR-193	low	KRAS	promotes cellular proliferation, differentiation, and migration	18
	miR-17-92	high	myc	promotes hyper-proliferation of lung epithelial cells	19
	miR-21	high	PTEN, PDCD4	promotes growth and invasion in NSCLC	20
	miR-137	low	SLC22A18	promotes aggressive tumor progression	21
	miR-451	low	RAB14	induces tumor differentiation and shorter survival	22
	miR-16	low	p27, Bcl-2, Bax, and caspase-3	induces cell proliferation and apoptosis	23
	miR-218	low	HMGB1	leads to aggressive cell proliferation, migration, and invasion	24
	miR-155	high	Apaf-1	resistance to therapy and associated with shorter survival	25
	miR-216	low	eIF4B, ZEB1	tumor growth, proliferation, metastasis, and chemoresistance	26
IPF	Let-7d	low	HMGA2	increases mesenchymal markers (ACTA2, VIM) and decreases epithelial markers (cytokeratin and TJP1)	27
	miR-21	high	SMAD7	promotes excessive extracellular matrix (ECM) gene transcription	28
	miR-96	high	FoxO3a	increases PI3K-Akt activity, thereby promoting IPF fibroblasts	29
	miR-326	low	3′ UTR of TGF-β	upregulates profibrotic genes	30
	miR-200	low	TGF-β signaling	induces epithelial-mesenchymal transition and tumor metastasis	31
CF	miR-126	low	TOM1	causes excessive inflammatory response and airway obstruction	32, 33
	miR-138	low	SIN3A	resuscitates the CFTR expression
	miR-155	high	MAPK and PI3K/Akt signaling	activates proinflammatory cytokine IL-8 to attract neutrophils	34
	miR-145 and miR-223	high	3′ UTR of CFTR	decrease CFTR expression and cause inflammation	35
	miR-509 and miR-494	high	NF-κB signaling	repress CFTR expression and induce pro-inflammatory cytokines	36
	miR-93 and miR-31	low	3′ UTR of IL-8, IRF-1	promote increased production of cathepsin S	37

High and low indicate whether the miRNA is elevated or reduced in lung-associated diseases, respectively. CF, cystic fibrosis; COPD, chronic obstructive pulmonary disease; IPF, idiopathic pulmonary fibrosis.