Mitochondrial Mutations and Genetic Factors Determining NAFLD Risk

Abstract

NAFLD (non-alcoholic fatty liver disease) is a widespread liver disease that is often linked with other life-threatening ailments (metabolic syndrome, insulin resistance, diabetes, cardiovascular disease, atherosclerosis, obesity, and others) and canprogress to more severe forms, such as NASH (non-alcoholic steatohepatitis), cirrhosis, and HCC (hepatocellular carcinoma). In this review, we summarized and analyzed data about single nucleotide polymorphism sites, identified in genes related to NAFLD development and progression. Additionally, the causative role of mitochondrial mutations and mitophagy malfunctions in NAFLD is discussed. The role of mitochondria-related metabolites of the urea cycle as a new non-invasive NAFLD biomarker is discussed. While mitochondria DNA mutations and SNPs (single nucleotide polymorphisms) canbe used as effective diagnostic markers and target for treatments, age and ethnic specificity should be taken into account.

Keywords: NAFLD; NASH; SNPs; chronic inflammation; fibrosis; mitochondrial dysfunction; mitochondrial mutations; mitophagy; oxidative stress.

Figure 1

Involvement of the liver mitochondria in ammonia detoxification. Under NAFLD/NASH conditions, the expression and activities of CSP1 and OTC enzymes are reduced (magenta arrows) and the efficiency of the urea cycle is diminished, which leads to hyperammonemia (green arrows) and activation of pro-fibrotic and pro-inflammatory factors favoring the disease progression.