Long non-coding RNA H19 inhibition promotes hyperglycemia in mice by upregulating hepatic FoxO1 levels and promoting gluconeogenesis
In a previous report from our laboratory, it was reported that hepatic levels of the long non-coding RNA (lncRNA), H19 are decreased in diabetic mice which elevates hepatic gluconeogenesis and glucose output. But, the mechanisms of H19 inhibition in elevating gluconeogenic genes’ transcription and promoting hepatic glucose output were not known. In this study, we aimed to decipher this regulatory role of H19 on glucose metabolism and on FoxO1, an important transcriptional regulator of gluconeogenesis. While H19 inhibition in HepG2 cells increased the levels of FoxO1, its overexpression led to significant inhibition in FoxO1 levels, thereby identifying H19 as an important regulator of FoxO1. Our data also demonstrates that in the absence of H19, there is increased occupancy of p53 on the FoxO1 promoter that possibly is responsible for increased FoxO1 transcription. In vivo silencing of H19 in normal mice caused hyperglycemia, hyperinsulinemia and impaired glucose, insulin, and pyruvate tolerance. Serum triglyceride and cholesterol levels, however, did not show any change. H19 inhibition significantly elevated the hepatic levels of FoxO1 and all the gluconeogenic genes. While fasting increased gluconeogenic genes’ transcription, the levels of H19 were decreased and these patterns reversed upon refeeding the mice. Thus, gluconeogenic genes and H19 levels show inverse patterns of expression, and these results indicate towards an important regulatory role of the lncRNA, H19. It acts as an upstream regulator of gluconeogenesis by regulating the transcription of FoxO1, an important transcription factor of gluconeogenic genes, and hence, regulates hepatic glucose metabolism.
H19 regulates FoxO1 transcript and protein levels.
H19 inhibition increases p53 occupancy on the FoxO1 promoter that promotes FoxO1 transcription.
H19 inhibition in vivo induces hyperglycemia and impairs glucose, insulin, and pyruvate tolerance.
In vivo H19 inhibition increases the hepatic transcript levels of gluconeogenic genes and FoxO1.
Transcript levels of H19 and gluconeogenic genes are inversely regulated during fed and fasted states.
KeywordslncRNAs H19 FOXO1 p53 Liver Gluconeognenesis Diabetes
The authors acknowledge CSIR (NG and DK) and UGC (ST), New Delhi, India, for the fellowships. The authors thank the team of the Animal House facility of CSIR-IGIB for the assistance during the in vivo experiments. We thank Mr. Ananda K Mukherjee, CSIR-Institute of Genomics and Integrative Biology for his help in the chromatin-immunoprecipitation experiments.
This work was supported by funding from the Council of Scientific and Industrial Research (CSIR), New Delhi, India (BSC0123).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
- 10.Shao WJ, Tao LY, Gao C, Xie JY, Zhao RQ (2008) Alterations in methylation and expression levels of imprinted genes H19 and Igf2 in the fetuses of diabetic mice. Comp Med 58:341–346Google Scholar
- 12.Venkatraman A, He XC, Thorvaldsen JL, Sugimura R, Perry JM, Tao F, Zhao M, Christenson MK, Sanchez R, Yu JY, Peng L, Haug JS, Paulson A, Li H, Zhong XB, Clemens TL, Bartolomei MS, Li L (2013) Maternal imprinting at the H19-Igf2 locus maintains adult haematopoietic stem cell quiescence. Nature 500:345–349CrossRefGoogle Scholar
- 16.Gao Y, Wu F, Zhou J, Yan L, Jurczak MJ, Lee HY, Yang L, Mueller M, Zhou XB, Dandolo L, Szendroedi J, Roden M, Flannery C, Taylor H, Carmichael GG, Shulman GI, Huang Y (2014) The H19/let-7 double-negative feedback loop contributes to glucose metabolism in muscle cells. Nucleic Acids Res 42:13799–13811CrossRefGoogle Scholar
- 19.Kung CP, Murphy ME (2016) The role of the p53 tumor suppressor in metabolism and diabetes. J Endocrinol, 231:R61–R75Google Scholar
- 23.Li X, Gray SG, Flam F, Pietsch T, Ekstrom TJ (1998) Developmental-dependent DNA methylation of the IGF2 and H19 promoters is correlated to the promoter activities in human liver development. Int J Dev Biol 42:687–693Google Scholar
- 32.Abdul-Wahed A, Gautier-Stein A, Casteras S, Soty M, Roussel D, Romestaing C, Guillou H, Tourette JA, Pleche N, Zitoun C, Gri B, Sardella A, Rajas F, Mithieux G (2014) A link between hepatic glucose production and peripheral energy metabolism via hepatokines. Mol Metab 3:531–543CrossRefGoogle Scholar