Abstract: SA-PO852
LncRNA GAS5 Regulates TGF-β-Induced Renal Fibrosis via Smad3-Dependent Pathway
Session Information
- Molecular Mechanisms of CKD - III
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1201 Glomerular Diseases: Fibrosis and Extracellular Matrix
Authors
- Zhang, Yingying, shanghai tongji hospital, Shanghai, China
- Yu, Chen, Shanghai Tongji Hospital, Shanghai, China
Background
Increasing evidence shows that long noncoding RNAs (lncRNAs) play an important role in kidney disease. It is well known that some lncRNAs have been reported in renal fibrosis and renal inflammation, such as PVT1 is the first identified lncRNA-associated kidney disease. In our previous study, we found lncRNA- growth arrest-specific 5 (GAS5) was highly decreased in the fibrotic kidney of mouse unilateral ureteral obstructive nephropathy (UUO), however, the underlying mechanism of GAS5 in the pathogenesis of kidney disease remain largely unclear.
Methods
Firstly, we detected GAS5 expression in UUO kidney by using realtime-PCR and in situ hybridization(ISH). Then, we tested whether TGF-β1 had any effect on GAS5 expression in mouse tubule epithelial cell (mTEC), since TGF-β signaling is one of the major mediators of renal fibrosis. Finally, we aimed to investigate the biological role of GAS5 after over-expression or silencing its expression in mTEC.
Results
ISH staining showed that GAS5 was expressed by mTECs, interstitial fibroblasts in normal renal tissue, both in the nucleus and cytoplasm pattern. In vitro, GAS5 was down-regulated by TGF-b1 as dose-dependent. Over-expression of GAS5 blocked TGF-b1-induced collagen I, fibronectin and alpha-smooth muscle actin (a-SMA) expressions, however, silencing GAS5 promoted the expressions of these markers. Mechanistic studies revealed that Smad3, not Smad2, drove the expression of GAS5. TGF-b1 reduced GAS5 expression in both of the Smad3 and Smad2 wild-type MEFs, which was blunted in Smad3 knock-out MEFs but still decreased in Smad2 knock-out MEFs. The addition of SIS3 recovered TGF-b1-induced expression of GAS5 in mTECs. Finally, we also found knockdown of GAS5 promoted TGF-β1-induced G2/M arrest, which might contribute to renal fibrosis via Smad3 pathway.
Conclusion
Taken together, our results have uncovered a GAS5-based mechanism that modulated TGF-β/Smad3 signaling by targeting extracellular matrix formation and cell cycle disruption.