Epigenetic regulation of lipoprotein lipase gene via BRD4, which is potentially associated with adipocyte differentiation and insulin resistance.

Abstract

Lipoprotein lipase (LPL) is the rate-controlling enzyme for the accumulation of triacylglycerol into adipocytes, which acts by digesting it into glycerol and fatty acids. In this study, we found that treatment with (+)-JQ1, an inhibitor of the bromodomain and extra-terminal (BET) family proteins, for 4 days from the end of stimulation to induce adipocyte differentiation reduced binding of BRD4, a BET family member, within the gene body of Lpl. This eventually downregulated the expression of Lpl in 3T3-L1 adipocytes. Longer treatment for 8 days reduced the acetylation of histones H3 and H4 within the gene body of Lpl and subsequent Lpl expression. Lpl expression in mesenteric adipose tissues was lower in Brd4+/- heterozygous mice at 14 days after birth than in wild-type mice at the same age. Furthermore, treatment with an inducer of insulin resistance, tumor necrosis factor-α, reduced BRD4 binding and histone acetylation in the gene body of Lpl and its expression. These results indicate that transcriptional elongation of Lpl controlled by BRD4 may be associated with adipocyte differentiation, and that its suppression is potentially associated with insulin resistance of adipocytes.

• Authors: Takuya Inoue, Natsuyo Hariya, Yuko Imamochi, Anup Dey, Keiko Ozato, Toshinao Goda, Takeo Kubota, Kazuki Mochizuki
• Journal: European journal of pharmacology (Eur J Pharmacol) Vol. 858 Pg. 172492 (Sep 05 2019) ISSN: 1879-0712 [Electronic] Netherlands
• PMID: 31233750 (Publication Type: Journal Article)
• Copyright: Copyright © 2019 Elsevier B.V. All rights reserved.

Chemical References

• (+)-JQ1 compound
• Azepines
• Brd4 protein, mouse
• Histones
• Nuclear Proteins
• Transcription Factors
• Triazoles
• Tumor Necrosis Factor-alpha
• Lipoprotein Lipase

Topics

• 3T3-L1 Cells
• Acetylation (drug effects)
• Adipocytes (cytology, drug effects)
• Adipose Tissue (cytology, drug effects)
• Animals
• Azepines (pharmacology)
• Cell Differentiation (drug effects, genetics)
• Epigenesis, Genetic
• Gene Expression Regulation, Enzymologic (drug effects, genetics)
• Heterozygote
• Histones (metabolism)
• Insulin Resistance (genetics)
• Lipoprotein Lipase (genetics)
• Mice
• Nuclear Proteins (metabolism)
• Transcription Factors (metabolism)
• Triazoles (pharmacology)
• Tumor Necrosis Factor-alpha (pharmacology)