Deciphering the role of taurine-upregulated gene 1 in liver diseases: Mechanisms, clinical relevance, and emerging therapeutic opportunities

Table 2 The regulatory axis of taurine upregulated gene 1 in non-cancerous liver disease

Function	Target miRNA	Target protein	Molecular mechanism	TUG1 role	Ref.
Liver injury
-	-	-	Overexpression of TUG1 suppresses endoplasmic reticulum stress, reduces apoptosis, and upregulates anti-apoptotic proteins	Cryoprotective	Su et al[134]
MiRNA sponge/ceRNA	MiR-194	SIRT1	TUG1 sequesters miR-194, a negative regulator of SIRT1	Anti-apoptotic, anti-inflammatory	Gu et al[135]
MiRNA sponge/ceRNA	MiR-140-5p	TNF	TUG1 sequesters miR-140-5p, a negative regulator of TNF-α	Pro-apoptotic, pro-inflammatory	Liu et al[136]
Liver fibrosis/cirrhosis
-	MiR-29b	COL1A1/α-SMA	Overexpression of TUG1 is positively correlated with expression of COL1A1 and α-SMA while negatively correlated with miR-29b	Pro-fibrotic	Han et al[137]
-	-	PDK4	Overexpression of TUG1 is positively correlated with expression of PDK4	Anti-ferroptotic	Zhang et al[138]
MiRNA sponge/ceRNA	MiR-142-3p	ATG5	TUG1 sequesters miR-142-3p, a negative regulator of ATG5	Pro-autophagic endothelial-mesenchymal transition-promoting	Zhang et al[139]
Metabolic dysfunction–associated steatotic liver disease
MiRNA sponge/ceRNA	MiR-1934-3p	SelenoF	TUG1 sequesters miR-1934-3p, a negative regulator of SelenoF	Glucose-lipid metabolism regulator	Wang et al[140]

A-SMA: Alpha-smooth muscle actin; ATG5: Autophagy protein 5; CeRNA: Competitive endogenous RNA; COL1A1: Collagen type I alpha 1; MiRNAs: MicroRNAs; PDK4: Pyruvate dehydrogenase kinase 4; SelenoF: Selenoprotein F; SIRT1: Sirtuin 1; TNF: Tumor necrosis factor; TUG1: Taurine upregulated gene 1.