Noncoding RNAs as additional mediators of epigenetic regulation in nonalcoholic fatty liver disease

Table 1 Selected microRNAs shown to be highly involved in the pathogenesis of nonalcoholic fatty liver disease

miRNA	Circulation level	Tissue expression	Main functional and pathophysiological impacts	Ref.
miR-21	↑	↑	Promotes lipogenesis	[38-40,42,44]
			Involved in NASH, fibrosis, and HCC
			Targets several metabolic and inflammatory signaling pathways related to the pathogenesis of NAFLD
miR-29a	↑	↓	Highly connected with the diagnostic relevance of NAFLD, NASH, and HCC	[31,53, 52,58]
			Modulates oxidative stress and inflammation in the context of NAFLD
miR-33a/b	↑	↑	Involved in lipid metabolism, glucose homeostasis and hepatic lipogenesis	[61-63,65]
			Associated with steatosis and inflammation in patients with NAFLD/NASH
miR-34a	↑	↑	Regulates lipoprotein metabolism and promotes liver steatosis	[72,73,75]
			Involved in NAFLD/NASH
			Correlates with the severity of hepatic inflammatory activity
			Can serve as a biomarker to distinguish NAFLD from NASH patients
miR-122	↑	↓	Modulates several genes linked to chronic hepatic pathology and lipid metabolism	[74,82-84]
			Promotes hepatic steatosis
			Serum miR-122 correlates positively with markers of NAFLD severity as well as with NASH
miR-155	↑	↑	Regulates key cellular events in NAFLD/NASH	[96,97]
			Promotes insulin resistance
miR-192	↑	↓	Significantly elevated in NAFLD patients and positively associated with hepatic inflammatory activity score and disease progression	[32,80,100]
			Increased in serum from NASH patients compared with steatosis
			Could be a potential biomarker of NAFLD and NASH
miR-375	↑	↑	Involved in the pathogenesis of NAFLD/NASH/fibrosis	[80,102]
			Key regulator of glucose homeostasis and insulin secretion

HCC: Hepatocellular carcinoma; miRNAs: MicroRNAs; NAFLD: Nonalcoholic fatty liver disease; NASH: Nonalcoholic steatohepatitis.