Yiyi Zhu1, Weiwei Gui1, Xihua Lin2, Hong Li3. 1. Department of Endocrinology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 7th Floor, Tower I, 3 East Qingchun Road, Hangzhou, ZJ 571, China. 2. Department of Endocrinology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 7th Floor, Tower I, 3 East Qingchun Road, Hangzhou, ZJ 571, China. Electronic address: linxihua@zju.edu.cn. 3. Department of Endocrinology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 7th Floor, Tower I, 3 East Qingchun Road, Hangzhou, ZJ 571, China. Electronic address: srrshnfm@zju.edu.cn.
Abstract
PURPOSE: The metabolic syndrome (MetS) is characterized of a cluster of medical disorders. Altered function of adipose tissue has a significant impact on whole-body metabolism and represents a key driver for MetS. In this study, we aim to explore the function of human circular RNA H19 (hsa_circH19) in human adipose-derived stem cells (hADSCs). METHODS: The blood samples from MetS patients and normal subjects were used to determine the expression level of the hsa_circH19. After knock-down of hsa_circH19 in hADSCs, we measured the expression of adipogenic genes. Oil red O, Nile red staining assay and triglyceride assessment were performed to examine the role of hsa_circH19 in hADSCs differentiation. Then, RNA Pull-down and RIP assays were conducted to explore the related RNA binding protein of hsa_circH19. IF was performed to determine the potential molecular regulatory mechanism. RESULTS: After accounting for confounding factors, high levels of hsa_circH19 remained an independent risk factor for MetS. Furthermore, the knockdown of hsa_circH19 significantly increased the expression of adipogenic genes and the formation of lipid droplets. Bioinformatics analyses revealed that has_circH19 shared multiple binding sites with polypyrimidine tract-binding protein 1 (PTBP1) and their interaction was validated by circRNA pull-down and RIP assays. Mechanistically, depletion of hsa_circH19 triggered translocation of sterol-regulatory element binding proteins (SREBP1) from cytoplasm to nucleus in the presence of PTBP1. CONCLUSION: Our experiments suggest that knockdown of hsa_circH19 promotes hADCSs adipogenic differentiation via targeting of PTBP1. In consequence, the expression of hsa_circH19 might correlated to lipid metabolism in adipose tissue from MetS.
PURPOSE: The metabolic syndrome (MetS) is characterized of a cluster of medical disorders. Altered function of adipose tissue has a significant impact on whole-body metabolism and represents a key driver for MetS. In this study, we aim to explore the function of human circular RNA H19 (hsa_circH19) in human adipose-derived stem cells (hADSCs). METHODS: The blood samples from MetSpatients and normal subjects were used to determine the expression level of the hsa_circH19. After knock-down of hsa_circH19 in hADSCs, we measured the expression of adipogenic genes. Oil red O, Nile red staining assay and triglyceride assessment were performed to examine the role of hsa_circH19 in hADSCs differentiation. Then, RNA Pull-down and RIP assays were conducted to explore the related RNA binding protein of hsa_circH19. IF was performed to determine the potential molecular regulatory mechanism. RESULTS: After accounting for confounding factors, high levels of hsa_circH19 remained an independent risk factor for MetS. Furthermore, the knockdown of hsa_circH19 significantly increased the expression of adipogenic genes and the formation of lipid droplets. Bioinformatics analyses revealed that has_circH19 shared multiple binding sites with polypyrimidine tract-binding protein 1 (PTBP1) and their interaction was validated by circRNA pull-down and RIP assays. Mechanistically, depletion of hsa_circH19 triggered translocation of sterol-regulatory element binding proteins (SREBP1) from cytoplasm to nucleus in the presence of PTBP1. CONCLUSION: Our experiments suggest that knockdown of hsa_circH19 promotes hADCSs adipogenic differentiation via targeting of PTBP1. In consequence, the expression of hsa_circH19 might correlated to lipid metabolism in adipose tissue from MetS.