The developmental Wnt signaling pathway effector β-catenin/TCF mediates hepatic functions of the sex hormone estradiol in regulating lipid metabolism

• Published in: PLoS biology 2019-10, Vol.17 (10), p.e3000444
• Main Authors: Tian, Lili, Shao, Weijuan, Ip, Wilfred, Song, Zhuolun, Badakhshi, Yasaman, Jin, Tianru
• Format: Article
• Language: English
• Subjects: 17β-Estradiol; Activation; Animals; Attenuation; Benzodioxoles - pharmacology; beta Catenin - genetics; beta Catenin - metabolism; Biology and Life Sciences; Body weight gain; Diabetes; Diet; Diet, High-Fat - adverse effects; Endocrinology; Estradiol - pharmacology; Estrogens; Female; Gender; Gender aspects; Gene expression; Gene Expression Regulation, Developmental; Glucose; Glucose - metabolism; Glucose tolerance; Growth factors; Health care networks; Hepatocytes; Hepatocytes - drug effects; Hepatocytes - metabolism; High fat diet; Homeostasis; Hormones; Hospitals; Immunological tolerance; Insulin; Insulin Resistance; Intolerance; Kinases; Ligands; Lipid metabolism; Lipid Metabolism - drug effects; Lipid Metabolism - genetics; Lipids; Liver; Liver - drug effects; Liver - metabolism; Lymphocytes; Lymphocytes T; Male; Medicine; Medicine and Health Sciences; Metabolic disorders; Metabolism; Mice; Mice, Transgenic; Obesity - etiology; Obesity - genetics; Obesity - metabolism; Obesity - pathology; Ovariectomy; Peptide hormones; Peptides; Phosphorylation; Physiology; Proteins; Quinolines - pharmacology; Receptors, Estrogen - antagonists & inhibitors; Receptors, Estrogen - genetics; Receptors, Estrogen - metabolism; Receptors, G-Protein-Coupled - antagonists & inhibitors; Receptors, G-Protein-Coupled - genetics; Receptors, G-Protein-Coupled - metabolism; Research and Analysis Methods; Sex differences; Sex Factors; Sex hormones; Signal transduction; Signaling; Sterol Regulatory Element Binding Protein 1 - genetics; Sterol Regulatory Element Binding Protein 1 - metabolism; Sterol regulatory element-binding protein; Transcription Factor 7-Like 2 Protein - genetics; Transcription Factor 7-Like 2 Protein - metabolism; Transcription factors; Transgenic mice; Wnt protein; Wnt Signaling Pathway; β-Catenin
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.3000444

The bipartite transcription factor β-catenin (β-cat)/T cell factor (TCF), formed by free β-cat and a given TCF family member, serves as the effector of the developmental Wnt signaling cascade. β-cat/TCFs also serve as effectors of certain peptide hormones or growth factors during adulthood. We reported that liver-specific expression of dominant-negative Transcription factor 7 like 2 (TCF7L2DN) led to impaired glucose disposal. Here we show that, in this LTCFDN transgenic mouse model, serum and hepatic lipid contents were elevated in male but not in female mice. In hepatocytes, TCF7L2DN adenovirus infection led to stimulated expression of genes that encode lipogenic transcription factors and lipogenic enzymes, while estradiol (E2) treatment attenuated the stimulation, associated with Wnt-target gene activation. Mechanistically, this E2-mediated activation can be attributed to elevated β-cat Ser675 phosphorylation and TCF expression. In wild-type female mice, ovariectomy (OVX) plus high-fat diet (HFD) challenge impaired glucose disposal and insulin tolerance, associated with increased hepatic lipogenic transcription factor sterol regulatory element-binding protein 1-c (SREBP-1c) expression. In wild-type mice with OVX, E2 reconstitution attenuated HFD-induced metabolic defects. Some of the attenuation effects, including insulin intolerance, elevated liver-weight gain, and hepatic SREBP-1c expression, were not affected by E2 reconstitution in HFD-fed LTCFDN mice with OVX. Finally, the effects of E2 in hepatocytes on β-cat/TCF activation can be attenuated by the G-protein-coupled estrogen receptor (GPER) antagonist G15. Our study thus expanded the scope of functions of the Wnt pathway effector β-cat/TCF, as it can also mediate hepatic functions of E2 during adulthood. This study also enriches our mechanistic understanding of gender differences in the risk and pathophysiology of metabolic diseases.