Components of the endocannabinoid system: Hepatic expression levels of the cannabinoid receptors and microRNAs

Abstract

The endocannabinoid system includes cannabinoid receptors, endogenous ligands, and enzymes to maintain homeostasis in the human body. It is involved in the regulation of various physiological processes as food intake, lipogenesis, and inflammation. In addition, the endocannabinoid system has emerged as a major regulator associated with several diseases. It is known that cannabinoid receptors (CBRs) are expressed in the liver and hepatic immune cells during disease onset. A single microRNA (miRNA, miR) is estimated to target hundreds of different mRNAs, and a single mRNA can be regulated by more than one miRNA. Thus, miRNAs that regulate posttranscriptional gene expression are likely to be highly useful as biomarkers for treating acute or chronic liver disease.Studies over the past decade show that miRNAs are abundant in the liver and modulate a variety of liver functions. It is reported that mRNA targets of the over 30 miRNAs include many addiction-related genes. Studies suggest that especially miR-30b-5p, miR-22, miR-33a, miR-497, miR-145, miR-27b, and miR-155 among miRNAs in the liver interact with cannabinoid receptors. Consequently, studies have shown that some miRNAs control cannabinoid signaling by regulating the expression of CBRs. Therefore, CBRs agonist/antagonist can be used to treat liver disease and related complications. miRNA levels can be analyzed in blood and used in the near future as a diagnostic biomarker for different stages of liver diseases. © 2023 Elsevier Inc. All rights reserved.