The role and possible mechanism of long noncoding RNA PVT1 in modulating 3T3-L1 preadipocyte proliferation and differentiation.

Obesity is considered as a high-risk susceptibility state for most metabolic disorders and is directly related to preadipocyte differentiation or adipogenesis. Long noncoding RNAs (lncRNAs) are the key factors which have regulatory functions on various critical physiological and biological processes. PVT1 was identified as an oncogenic lncRNA which could promote angiogenesis in gastric cancer. However, the functions and molecular pathways related to PVT1 in adipogenesis had not been clarified yet. In the current study, the purpose was to identify the effects of lncRNA PVT1 on adipogenesis and the relevant molecular processes. Quantitative real-time polymerase chain reaction (RT-qPCR) was used to quantify PVT1 expression. The mechanism for PVT1 to participate in 3T3-L1 adipogenesis was identified by lentivirus-mediated gain- and loss-of-function tests. The potential association of PVT1 with cell viability was checked by CCK-8 assay and EdU staining. The gene expression for cytokines was determined by quantitative PCR (qPCR) and western blotting. PVT1 expression level was strongly upregulated after 3T3-L1 preadipocytes differentiated. In mice, PVT1 was abundantly expressed in adipose tissue, and the obese mice had higher PVT1 expression in adipose tissue than that of nonobese mice. Predominantly, PVT1 was found inside the nuclei. Overexpressed PVT1 could promote 3T3-L1 adipocyte differentiation as proved, which was the cause for the ability to accelerate lipid accumulation, by upregulating the expression of peroxisome proliferator activated receptor gamma, CCAAT/enhancer-binding protein α, and adipocyte protein 2, while knockdown of PVT1 caused opposite effects. The RNA immunoprecipitation demonstrated the binding relationship between PVT1 and STAT3 suggesting the potential role of STAT3 in 3T3-L1 preadipocyte differentiation. Furthermore, PVT1 could promote fatty acid synthesis but inhibit fatty acid oxidation. PVT1 was positively associated with 3T3-L1 preadipocyte differentiation, which highlighted the potential of PVT1 as a therapeutic target for obesity treatment.