Expression level of long non-coding RNA MALAT1, GAS5, DANCR and TUG1 in peripheral blood leukocytes of patients with non-alcoholic fatty liver disease

Purpose: Comparative analysis of the expression level of long non-coding RNAs MALAT1, GAS5, DANCR, TUG1 in peripheral blood leukocytes (PBL) of healthy people and patients with NAFLD (liver steatosis, NASH of varying activity, liver cirrhosis). Materials and methods: We examined 106 patients diagnosed with NAFLD for the first time: 31 patients with liver steatosis (LS), 64 patients with weak (WA), moderate (MA) and high (HA) NASH activity and 11 patients at the stage of liver cirrhosis (LC). The control group consisted of 30 healthy donors. The mRNA level of the TUG1, DANCR, MALAT1, GAS5 genes in PBL was determined by RT-PCR. Results: A higher level of expression of the TUG1 gene was registered in the PBL of patients with NASH-WA compared to LS, and a tendency was revealed to increase the level of TUG1 mRNA in the PBL with increasing NASH activity, which indicates the possibility of using the level of TUG1 expression in the PBL as a minimally invasive diagnostic (to distinguish between LS and NASH-WA) and a prognostic marker (with the progression of NAFLD). Analysis of the expression level of lncRNA MALAT1 showed no significant differences between all studied groups. Results were obtained indicating complex dynamics of the GAS5 expression level: the level of transcripts increases during the formation of liver steatosis and then decreases during the transition to NASH. It was shown that the level of DANCR expression in the PBL of patients with NASH-WA is significantly lower than in patients with liver steatosis and NASH-MA. Conclusion: New data were obtained on the expression level of the MALAT1, GAS5, DANCR, TUG1 lncRNAs in the PBL of patients with NAFLD, indicating the possibility of using the level of TUG1 expression in the PBL as a minimally invasive diagnostic and prognostic marker in NAFLD. It has also been shown that the level of DANCR mRNA in PBL may have some diagnostic value in distinguishing between LS and NASH-WA.