Long Noncoding RNAGAS5Suppresses 3T3-L1 Cells Adipogenesis Through miR-21a-5p/PTEN Signal Pathway

Abstract

Emerging studies indicated that both long noncoding RNAs and micro-RNAs play crucial roles in the mediation of adipogenesis, which is closely linked to obesity-related diseases. However, the mechanisms of lncRNA-miRNAs coregulating in adipogenesis are still largely unknown. In this study, we determined that lncRNA growth arrest-specific 5 (GAS5) presented an opposite expression pattern with miR-21a-5p in 3T3-L1 adipocytes development. To explore the role of GAS5 in adipogenesis, pcDNA3.1-GAS5 expression vectors and GAS5-siRNAs were used to perform GAS5 overexpression and knockdown, respectively. Ectopic expression of GAS5 dramatically reduced miR-21a-5p level and suppressed the proliferation of 3T3-L1 preadipocytes, while silencing GAS5 slightly increased miR-21a-5p expression but had no significant influence on the cell viability. In addition, overexpression of GAS5 remarkably decreased the mRNA and protein levels of adipogenic marker genes, and resulted in a notable reduction of lipid accumulation. In contrast, overexpressing miR-21a-5p significantly facilitated differentiation of 3T3-L1 cells. By target gene prediction and luciferase reporter assay, we suggested that GAS5 might indirectly improve the expression of phosphatase and tensin homolog (PTEN) by repressing miR-21a-5p in a miRNA-based regulatory mechanism. Together, GAS5 plays a suppressive role in 3T3-L1 cells adipogenesis, which further highlights the importance of lncRNAs in adipogenesis.

Identification of Long Non-coding RNAs Expressed During Early Adipogenesis

“…Moreover, our differentiation was conducted at 100% confluence. Our data agreed well with the published data (Coccia et al, 1992;Liu et al, 2018).…”

“…Chen et al (2017) found that overexpression of U90926 remarkably inhibits 3T3-L1 preadipocyte differentiation. Another lncRNA, growth arrest-specific 5, or Gas5, was reported that its expression level increases along with the adipocyte differentiation after 24 to 96 hours of induction in 3T3-L1 cells and high cell density during culture also induces its expression (Coccia et al, 1992;Liu et al, 2018). We observed that Gas5 expression increased by 1.56-fold with FDR 0.3% after 2 days of differentiation.…”

“…Our data agreed with their findings. Interestingly, both Liu et al (2018) and studied Gas5 in adipogenesis in 3T3-L1 cells for 4 days differentiation induction and mesenchymal stem cells for 3 or more days induction, respectively. Both groups concluded that Gas5 suppresses adipogenesis, through other microRNAs, which is controversy to our results Liu et al, 2018).…”

“…Interestingly, both Liu et al (2018) and studied Gas5 in adipogenesis in 3T3-L1 cells for 4 days differentiation induction and mesenchymal stem cells for 3 or more days induction, respectively. Both groups concluded that Gas5 suppresses adipogenesis, through other microRNAs, which is controversy to our results Liu et al, 2018). However, this could be explained that both groups studied Gas5 for more than 3 days of differentiation (we did 2 days) and they used overexpression system and knockdown approach, which might result in cell fate during early adipogenesis.…”

Long non‑coding RNA GAS5 increases the radiosensitivity of A549 cells through interaction with the miR‑21/PTEN/Akt axis

“…miR-624-3p, miR-130a, and miR-21 (40)(41)(42). There are several potential binding sites of miR-21 on the PTEN 3'UTR, such as GAUAAG and UCUG*UG*GCUA (43,44). PTEN is an inhibitor of the PI3K/Akt signaling pathway (45), and the PTEN/Akt axis is a pivotal regulatory pathway in IR-induced cell apoptosis.…”