Role of miR-223 in the pathophysiology of liver diseases

MiRNAs are small, noncoding RNAs, which can regulate gene expression posttranscriptionally, and they have emerged as key factors in disease biology by aiding in disease development and progression. MiR-223 is highly conserved during evolution and it was first described as a modulator of hematopoietic lineage differentiation. MiR-223 has an essential part in inflammation by targeting the nuclear factor-κB pathway and the nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome. Recent studies have shown that miR-223 expression is deregulated in various types of liver diseases, including hepatitis virus infections, alcohol-induced liver injury, drug-induced liver injury, non-alcoholic fatty liver disease, cirrhosis, and hepatocellular carcinoma. As inflammatory and immune factors are involved in the occurrence and progress of liver diseases, deregulated miR-223 may participate in the pathogenesis of these conditions by influencing neutrophil infiltration, macrophage polarization, and inflammasome activation. This review first summarizes the present understanding of the biological functions of miR-223, including its gene location and transcription regulation, as well as its physiological role in hematopoietic differentiation. This review then focuses on the role of miR-223 in liver pathophysiology and its potential applications as a diagnostic biomarker and therapeutic target in liver diseases. Liver disease: a tiny trigger for liver damage A tiny RNA molecule involved with gene regulation may offer an appealing target for diagnosing and treating various liver diseases. MicroRNA-223 (miR-223) was first identified as controlling gene activity in a wide variety of immune cells. A review from researchers led by Yanning Liu at China’s Zhejiang University in Hangzhou details how abnormal miR-223 also contributes to liver damage in a variety of conditions, although questions still remain about how it functions in different liver disorders. The authors highlight studies linking miR-223 with the development of fibrosis and cirrhosis, and with the inflammatory response to injury from drugs, alcohol, or infection. This could make this microRNA a useful diagnostic biomarker. The authors also identify therapeutic opportunities to modulate this molecule, referring to several studies on the manipulation of miR-223 to treat hepatitis.