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Sinha RA, Yen PM. Metabolic Messengers: Thyroid Hormones. Nat Metab 2024; 6:639-650. [PMID: 38671149 PMCID: PMC7615975 DOI: 10.1038/s42255-024-00986-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 01/15/2024] [Indexed: 04/28/2024]
Abstract
Thyroid hormones (THs) are key hormones that regulate development and metabolism in mammals. In man, the major target tissues for TH action are the brain, liver, muscle, heart, and adipose tissue. Defects in TH synthesis, transport, metabolism, and nuclear action have been associated with genetic and endocrine diseases in man. Over the past few years, there has been renewed interest in TH action and the therapeutic potential of THs and thyromimetics to treat several metabolic disorders such as hypercholesterolemia, dyslipidaemia, non-alcoholic fatty liver disease (NAFLD), and TH transporter defects. Recent advances in the development of tissue and TH receptor isoform-targeted thyromimetics have kindled new hope for translating our fundamental understanding of TH action into an effective therapy. This review provides a concise overview of the historical development of our understanding of TH action, its physiological and pathophysiological effects on metabolism, and future therapeutic applications to treat metabolic dysfunction.
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Affiliation(s)
- Rohit A Sinha
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
| | - Paul M Yen
- Laboratory of Hormonal Regulation, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore.
- Div. Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA.
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Marino L, Kim A, Ni B, Celi FS. Thyroid hormone action and liver disease, a complex interplay. Hepatology 2023:01515467-990000000-00521. [PMID: 37535802 DOI: 10.1097/hep.0000000000000551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023]
Abstract
Thyroid hormone action is involved in virtually all physiological processes. It is well known that the liver and thyroid are intimately linked, with thyroid hormone playing important roles in de novo lipogenesis, beta-oxidation (fatty acid oxidation), cholesterol metabolism, and carbohydrate metabolism. Clinical and mechanistic research studies have shown that thyroid hormone can be involved in chronic liver diseases, including alcohol-associated or NAFLD and HCC. Thyroid hormone action and synthetic thyroid hormone analogs can exert beneficial actions in terms of lowering lipids, preventing chronic liver disease and as liver anticancer agents. More recently, preclinical and clinical studies have indicated that some analogs of thyroid hormone could also play a role in the treatment of liver disease. These synthetic molecules, thyromimetics, can modulate lipid metabolism, particularly in NAFLD/NASH. In this review, we first summarize the thyroid hormone signaling axis in the context of liver biology, then we describe the changes in thyroid hormone signaling in liver disease and how liver diseases affect the thyroid hormone homeostasis, and finally we discuss the use of thyroid hormone-analog for the treatment of liver disease.
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Affiliation(s)
- Luigi Marino
- Department of Medicine, UConn Health, University of Connecticut, Farmington, Connecticut, USA
| | - Adam Kim
- Division of Gastroenterology and Hepatology, Department of Medicine, UConn Health, University of Connecticut, Farmington, Connecticut, USA
| | - Bin Ni
- Alliance Pharma, Philadelphia, Pennsylvania, USA
| | - Francesco S Celi
- Department of Medicine, UConn Health, University of Connecticut, Farmington, Connecticut, USA
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3
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Copur S, Yavuz F, Kanbay M. Thyroid hormone Beta receptor agonists for treatment of kidney disease: A promising agent? Eur J Clin Invest 2023; 53:e13939. [PMID: 36537819 DOI: 10.1111/eci.13939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 01/03/2023]
Abstract
BACKGROUND Chronic kidney disease is a common disorder affecting a significant portion of the adult population with high mortality and morbidity. Obesity and hyperlipidemia are prevalent in chronic kidney disease, and they may trigger fat accumulation in renal parenchyma and eventually fatty kidney. Chronic kidney disease and fatty kidney are also strongly associated with nonalcoholic fatty liver disease. Because they both lead to detrimental effects on organ function, they both need to be treated effectively to improve the outcome. AIM In this narrative review, we have hypothesized that thyroid hormone beta receptor agonists, a novel drug group, may potentially be beneficial in the management of chronic kidney disease due to its promising outcomes among patients with nonalcoholic fatty liver disease, a condition sharing multiple common underlying pathophysiological mechanisms. RESULTS AND CONCLUSION Thyroid hormone beta receptors are abundantly expressed in liver and kidney tissues, while both nonalcoholic fatty liver disease and chronic kidney disease share various similar pathophysiological mechanisms and triggers. Therefore, thyroid hormone beta receptor agonists may become a promising tool in the management of patients with chronic kidney disease.
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Affiliation(s)
- Sidar Copur
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Furkan Yavuz
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Mehmet Kanbay
- Department of Medicine, Division of Nephrology, Koc University School of Medicine, Istanbul, Turkey
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Eom YS, Wilson JR, Bernet VJ. Links between Thyroid Disorders and Glucose Homeostasis. Diabetes Metab J 2022; 46:239-256. [PMID: 35385635 PMCID: PMC8987680 DOI: 10.4093/dmj.2022.0013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/21/2022] [Indexed: 12/13/2022] Open
Abstract
Thyroid disorders and diabetes mellitus often coexist and are closely related. Several studies have shown a higher prevalence of thyroid disorders in patients with diabetes mellitus and vice versa. Thyroid hormone affects glucose homeostasis by impacting pancreatic β-cell development and glucose metabolism through several organs such as the liver, gastrointestinal tract, pancreas, adipose tissue, skeletal muscles, and the central nervous system. The present review discusses the effect of thyroid hormone on glucose homeostasis. We also review the relationship between thyroid disease and diabetes mellitus: type 1, type 2, and gestational diabetes, as well as guidelines for screening thyroid function with each disorder. Finally, we provide an overview of the effects of antidiabetic drugs on thyroid hormone and thyroid disorders.
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Affiliation(s)
- Young Sil Eom
- Division of Endocrinology, Department of Internal Medicine, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon, Korea
| | - Jessica R. Wilson
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic, Jacksonville, FL, USA
| | - Victor J. Bernet
- Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic, Jacksonville, FL, USA
- Corresponding author: Victor J. Bernet https://orcid.org/0000-0002-2477-5631 Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA E-mail:
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Chen Q, Wu C, Yao Z, Cai L, Ni Y, Mao S. Elevated thyroid hormones caused by high concentrate diets participate in hepatic metabolic disorders in dairy cows. Anim Biosci 2022; 35:1184-1194. [PMID: 34991199 PMCID: PMC9262717 DOI: 10.5713/ab.21.0397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/17/2021] [Indexed: 11/27/2022] Open
Abstract
Objective High concentrate diets are widely used to satisfy high-yielding dairy cows; however, long-term feeding of high concentrate diets can cause subacute ruminal acidosis (SARA). The endocrine disturbance is one of the important reasons for metabolic disorders caused by SARA. However, there is no current report about thyroid hormones involved in liver metabolic disorders induced by a high concentrate diet. Methods In this study, 12 mid-lactating dairy cows were randomly assigned to HC (high concentrate) group (60% concentrate of dry matter, n = 6) and LC (low concentrate) group (40% concentrate of dry matter, n = 6). All cows were slaughtered on the 21st day, and the samples of blood and liver were collected to analyze the blood biochemistry, histological changes, thyroid hormones, and the expression of genes and proteins. Results Compared with LC group, HC group showed decreased serum triglyceride, free fatty acid, total cholesterol, low-density lipoprotein cholesterol, increased hepatic glycogen, and glucose. For glucose metabolism, the gene and protein expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the liver were significantly up-regulated in HC group. For lipid metabolism, the expression of sterol regulatory element-binding protein 1, long-chain acyl-CoA synthetase 1, and fatty acid synthase in the liver was decreased in HC group, whereas carnitine palmitoyltransferase 1α and peroxisome proliferator activated receptor α were increased. Serum triiodothyronine, thyroxin, free triiodothyronine (FT3), and hepatic FT3 increased in HC group, accompanied by increased expression of thyroid hormone receptor (THR) in the liver. Conclusion Taken together, thyroid hormones may increase hepatic gluconeogenesis, β-oxidation and reduce fatty acid synthesis through the THR pathway to participate in the metabolic disorders caused by a high concentrate diet.
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Affiliation(s)
- Qu Chen
- Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Chen Wu
- Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhihao Yao
- Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Liuping Cai
- Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Yingdong Ni
- Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, China
| | - Shengyong Mao
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
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Birru RL, Liang HW, Farooq F, Bedi M, Feghali M, Haggerty CL, Mendez DD, Catov JM, Ng CA, Adibi JJ. A pathway level analysis of PFAS exposure and risk of gestational diabetes mellitus. Environ Health 2021; 20:63. [PMID: 34022907 PMCID: PMC8141246 DOI: 10.1186/s12940-021-00740-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/27/2021] [Indexed: 05/12/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) have been found to be associated with gestational diabetes mellitus (GDM) development, a maternal health disorder in pregnancy with negative effects that can extend beyond pregnancy. Studies that report on this association are difficult to summarize due to weak associations and wide confidence intervals. One way to advance this field is to sharpen the biologic theory on a causal pathway behind this association, and to measure it directly by way of molecular biomarkers. The aim of this review is to summarize the literature that supports a novel pathway between PFAS exposure and GDM development. Epidemiological studies demonstrate a clear association of biomarkers of thyroid hormones and glucose metabolism with GDM development. We report biologic plausibility and epidemiologic evidence that PFAS dysregulation of maternal thyroid hormones and thyrotropin (TSH) may disrupt glucose homeostasis, increasing the risk of GDM. Overall, epidemiological studies demonstrate that PFAS were positively associated with TSH and negatively with triiodothyronine (T3) and thyroxine (T4). PFAS were generally positively associated with glucose and insulin levels in pregnancy. We propose dysregulation of thyroid function and glucose metabolism may be a critical and missing component in the accurate estimation of PFAS on the risk of GDM.
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Affiliation(s)
- Rahel L. Birru
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
| | - Hai-Wei Liang
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
| | - Fouzia Farooq
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
| | - Megha Bedi
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA USA
| | - Maisa Feghali
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Catherine L. Haggerty
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
| | - Dara D. Mendez
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
| | - Janet M. Catov
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Carla A. Ng
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA USA
- Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
| | - Jennifer J. Adibi
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA USA
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
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Chen J, Dou P, Xiao H, Dou D, Han X, Kuang H. Application of Proteomics and Metabonomics to Reveal the Molecular Basis of Atractylodis Macrocephalae Rhizome for Ameliorating Hypothyroidism Instead of Hyperthyroidism. Front Pharmacol 2021; 12:664319. [PMID: 33959028 PMCID: PMC8095350 DOI: 10.3389/fphar.2021.664319] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/12/2021] [Indexed: 12/28/2022] Open
Abstract
As the treatments of diseases with Chinese herbs are holistic and characterized by multiple components, pathways, and targets, elucidating the efficacy of Chinese herbs in treating diseases, and their molecular basis, requires a comprehensive, network-based approach. In this study, we used a network pharmacology strategy, as well as in vivo proteomics and metabonomics, to reveal the molecular basis by which Atractylodis macrocephalae rhizome (AMR) ameliorates hypothyroidism. Eighteen main compounds from AMR and its fractions (volatile oil fraction, crude polysaccharides fraction, lactones fraction, oligosaccharide fraction, and atractyloside fraction) were identified by HPLC, and their targets were screened using the TCMSP database and Swiss Target Prediction. Disease targets were gathered from the TTD, CTD and TCMSP databases. Hub targets were screened by different plug-ins, such as Bisogene, Merge, and CytoNCA, in Cytoscape 3.7.1 software and analyzed for pathways by the DAVID database. Hypothyroidism and hyperthyroidism pharmacological models were established through systems pharmacology based on proteomic and metabolomic techniques. Finally, AMR and its fractions were able to ameliorate the hypothyroidism model to different degrees, whereas no significant improvements were noted in the hyperthyroidism model. The lactones fraction and the crude polysaccharides fraction were considered the most important components of AMR for ameliorating hypothyroidism. These amelioration effects were achieved through promoting substance and energy metabolism. In sum, the integrative approach used in this study demonstrates how network pharmacology, proteomics, and metabolomics can be used effectively to elucidate the efficacy, molecular basis, and mechanism of action of medicines used in TCM.
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Affiliation(s)
- Jing Chen
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Da Lian, China.,Department of Pharmacy, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, Zhejiang, China
| | - Peiyuan Dou
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Da Lian, China
| | - Hang Xiao
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Da Lian, China
| | - Deqiang Dou
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Da Lian, China
| | - Xueying Han
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Da Lian, China
| | - Haixue Kuang
- College of Pharmacy, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang, China
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Ha J, Lee J, Lim DJ, Lee JM, Chang SA, Kang MI, Kim MH. Association of serum free thyroxine and glucose homeostasis: Korea National Health and Nutrition Examination Survey. Korean J Intern Med 2021; 36:S170-S179. [PMID: 32506867 PMCID: PMC8009147 DOI: 10.3904/kjim.2019.160] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/07/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND/AIMS Thyroid hormones are involved in wide range of glucose metabolism functions. Overt thyroid dysfunctions are related to altered glucose homeostasis. However, it is not conclusive as to whether subtle changes in thyroid hormones within normal ranges can induce alterations in glucose homeostasis. The aim of this study was to evaluate the association between thyroid hormone and glucose homeostasis parameters in subjects without overt thyroid dysfunction based on nationwide population data. METHODS In the Sixth Korea National Health and Nutrition Examination Survey 2015 (n = 7,380), data were collected from subjects with insulin and thyroid function measurements who were older than 19-years-old. After the exclusion of 5,837 subjects, a total of 1,543 patients were included in the analysis. Subjects were categorized into the quartiles of the free thyroxine (FT4). Fasting glucose, insulin, homeostatic model assessment of insulin resistance and hemoglobin A1c (HbA1c) levels were considered to be glucose homeostasis parameters. RESULTS Subjects with the highest FT4 quartile showed significantly lower fasting insulin and HbA1c levels. A significant inverse correlation FT4 and HbA1c levels was observed (β = -0.261, p = 0.025). In the logistic regression analysis, the highest quartile of FT4 was demonstrated to lower the risk of HbA1c to a greater degree than the median by approximately 40%, after adjusting for confounders, compared to the lowest quartile (p = 0.028). CONCLUSION We demonstrated subjects with a lower FT4 quartile exhibited high risk of HbA1c levels above the median value in a representative Korean population. Subjects with the lowest FT4 quartile should be cautiously managed in terms of altered glucose homeostasis.
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Affiliation(s)
- Jeonghoon Ha
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jeongmin Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Dong-Jun Lim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jung-Min Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sang-Ah Chang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Moo-Il Kang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Min-Hee Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Correspondence to Min-Hee Kim, M.D. Division of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 1021 Tongil-ro, Eunpyeong-gu, Seoul 03312, Korea Tel: +82-2-961-4537 Fax: +82-2-968-7250 E-mail:
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Gauthier BR, Sola‐García A, Cáliz‐Molina MÁ, Lorenzo PI, Cobo‐Vuilleumier N, Capilla‐González V, Martin‐Montalvo A. Thyroid hormones in diabetes, cancer, and aging. Aging Cell 2020; 19:e13260. [PMID: 33048427 PMCID: PMC7681062 DOI: 10.1111/acel.13260] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/27/2020] [Accepted: 09/13/2020] [Indexed: 12/18/2022] Open
Abstract
Thyroid function is central in the control of physiological and pathophysiological processes. Studies in animal models and human research have determined that thyroid hormones modulate cellular processes relevant for aging and for the majority of age‐related diseases. While several studies have associated mild reductions on thyroid hormone function with exceptional longevity in animals and humans, alterations in thyroid hormones are serious medical conditions associated with unhealthy aging and premature death. Moreover, both hyperthyroidism and hypothyroidism have been associated with the development of certain types of diabetes and cancers, indicating a great complexity of the molecular mechanisms controlled by thyroid hormones. In this review, we describe the latest findings in thyroid hormone research in the field of aging, diabetes, and cancer, with a special focus on hepatocellular carcinomas. While aging studies indicate that the direct modulation of thyroid hormones is not a viable strategy to promote healthy aging or longevity and the development of thyromimetics is challenging due to inefficacy and potential toxicity, we argue that interventions based on the use of modulators of thyroid hormone function might provide therapeutic benefit in certain types of diabetes and cancers.
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Affiliation(s)
- Benoit R. Gauthier
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
- Biomedical Research Network on Diabetes and Related Metabolic Diseases‐CIBERDEM Instituto de Salud Carlos III Madrid Spain
| | - Alejandro Sola‐García
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
| | - María Ángeles Cáliz‐Molina
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
| | - Petra Isabel Lorenzo
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
| | - Nadia Cobo‐Vuilleumier
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
| | - Vivian Capilla‐González
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
| | - Alejandro Martin‐Montalvo
- Department of Cell Therapy and Regeneration Andalusian Center for Molecular Biology and Regenerative Medicine‐CABIMER Junta de Andalucía‐University of Pablo de Olavide‐University of Seville‐CSIC Seville Spain
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Ritter MJ, Amano I, Hollenberg AN. Thyroid Hormone Signaling and the Liver. Hepatology 2020; 72:742-752. [PMID: 32343421 DOI: 10.1002/hep.31296] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/30/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022]
Abstract
Thyroid hormone (TH) plays a critical role in maintaining metabolic homeostasis throughout life. It is well known that the liver and thyroid are intimately linked, with TH playing important roles in de novo lipogenesis, beta-oxidation (fatty acid oxidation), cholesterol metabolism, and carbohydrate metabolism. Indeed, patients with hypothyroidism have abnormal lipid panels with higher levels of low-density lipoprotein levels, triglycerides (triacylglycerol; TAG), and apolipoprotein B levels. Even in euthyroid patients, lower serum-free thyroxine levels are associated with higher total cholesterol levels, LDL, and TAG levels. In addition to abnormal serum lipids, the risk of nonalcoholic fatty liver disease (NAFLD) increases with lower free thyroxine levels. As free thyroxine rises, the risk of NAFLD is reduced. This has led to numerous animal studies and clinical trials investigating TH analogs and TH receptor agonists as potential therapies for NAFLD and hyperlipidemia. Thus, TH plays an important role in maintaining hepatic homeostasis, and this continues to be an important area of study. A review of TH action and TH actions on the liver will be presented here.
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Affiliation(s)
- Megan J Ritter
- Division of Endocrinology, Weill Cornell Medicine, New York, NY
| | - Izuki Amano
- Division of Endocrinology, Weill Cornell Medicine, New York, NY.,Department of Integrative Physiology, Gunma University Graduate School of Medicine, Maebashi, Japan
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11
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Keshavarz R, Akhlaghi A, Zamiri MJ, Jafarzadeh Shirazi MR, Saemi F, Akhlaghi AA, Zhandi M, Afrouziyeh M, Zuidhof MJ. The long-term oral administration of thyroxine: effects on blood hematological and biochemical features in broiler breeder hens. Poult Sci 2020; 98:7003-7008. [PMID: 31287884 PMCID: PMC8914009 DOI: 10.3382/ps/pez331] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 05/24/2019] [Indexed: 12/12/2022] Open
Abstract
Published data on the beneficial effect of short-term administration of thyroxine (T4) in broiler breeder hens to reduce the ascites incidence in their progeny chicks raises the question as to what extent might the long-term maternal administration of T4 affect the blood hematological and biochemical attributes in breeder hens. A total of 70 broiler breeder hens (47-wk-old) were randomly allotted to control or thyroxine treated (T4) groups. Pure T4 (0.3 mg/bird per day) was orally administered to T4 birds for 14 successive weeks, whereas the control group received the drinking water only. Blood samples were obtained from the brachial vein prior to the initiation of the trial as well as weeks 50, 53, 55, 57, 59, and 61 of age. Body weight was decreased but egg production was not affected by T4 treatment. Plasma concentration of T4, but not triiodothyronine (T3), was increased in T4-treated hens (P < 0.05). The total number of leukocytes and erythrocytes were also higher in T4 birds. A significant effect of time was observed for erythrocyte number and plasma cholesterol concentration (P < 0.05). The long-term administration of T4 did not affect the concentrations of serum calcium and plasma total protein, albumin, globulin, cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, very low density lipoprotein, alanine amino transferase, and aspartate amino transferase (P > 0.05). However, serum concentrations of phosphorus, glucose, and alkaline phosphatase were higher in T4 hens as compared to their control counterparts. In spite of differences in circulatory concentrations of a number of traits between the experimental groups, the recorded values were within their reference ranges. Therefore, the administration of T4 for an extended period of time had no apparent adverse effect on the clinical profile in subjected hens, which may practically support the implementation of this preventative treatment as an approach to decrease the ascites incidence; however, a lower incidence rate in the progeny chicks produced from hens receiving T4 for long-term periods of time remains to be elucidated.
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Affiliation(s)
- R Keshavarz
- Department of Animal Science, School of Agriculture, Shiraz University, Shiraz 71441-65186, Fars Province, Iran
| | - A Akhlaghi
- Department of Animal Science, School of Agriculture, Shiraz University, Shiraz 71441-65186, Fars Province, Iran
| | - M J Zamiri
- Department of Animal Science, School of Agriculture, Shiraz University, Shiraz 71441-65186, Fars Province, Iran
| | - M R Jafarzadeh Shirazi
- Department of Animal Science, School of Agriculture, Shiraz University, Shiraz 71441-65186, Fars Province, Iran
| | - F Saemi
- Department of Animal Science, School of Agriculture, Shiraz University, Shiraz 71441-65186, Fars Province, Iran
| | - A A Akhlaghi
- Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran 16635-148, Tehran Province, Iran
| | - M Zhandi
- Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj 31587-77871, Tehran Province, Iran
| | - M Afrouziyeh
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada
| | - M J Zuidhof
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada
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Tigani W, Rossi MP, Artimagnella O, Santo M, Rauti R, Sorbo T, Ulloa Severino FP, Provenzano G, Allegra M, Caleo M, Ballerini L, Bozzi Y, Mallamaci A. Foxg1 Upregulation Enhances Neocortical Activity. Cereb Cortex 2020; 30:5147-5165. [PMID: 32383447 DOI: 10.1093/cercor/bhaa107] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/03/2020] [Accepted: 04/05/2020] [Indexed: 12/19/2022] Open
Abstract
Foxg1 is an ancient transcription factor gene orchestrating a number of neurodevelopmental processes taking place in the rostral brain. In this study, we investigated its impact on neocortical activity. We found that mice overexpressing Foxg1 in neocortical pyramidal cells displayed an electroencephalography (EEG) with increased spike frequency and were more prone to kainic acid (KA)-induced seizures. Consistently, primary cultures of neocortical neurons gain-of-function for Foxg1 were hyperactive and hypersynchronized. That reflected an unbalanced expression of key genes encoding for ion channels, gamma aminobutyric acid and glutamate receptors, and was likely exacerbated by a pronounced interneuron depletion. We also detected a transient Foxg1 upregulation ignited in turn by neuronal activity and mediated by immediate early genes. Based on this, we propose that even small changes of Foxg1 levels may result in a profound impact on pyramidal cell activity, an issue relevant to neuronal physiology and neurological aberrancies associated to FOXG1 copy number variations.
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Affiliation(s)
- Wendalina Tigani
- Laboratory of Cerebral Cortex Development, Neuroscience Area, SISSA, Trieste 34136, Italy
| | - Moira Pinzan Rossi
- Laboratory of Cerebral Cortex Development, Neuroscience Area, SISSA, Trieste 34136, Italy.,AgenTus Therapeutics, Inc., Cambridge CB4 OWG, United Kingdom
| | - Osvaldo Artimagnella
- Laboratory of Cerebral Cortex Development, Neuroscience Area, SISSA, Trieste 34136, Italy
| | - Manuela Santo
- Laboratory of Cerebral Cortex Development, Neuroscience Area, SISSA, Trieste 34136, Italy
| | - Rossana Rauti
- Laboratory of Neurons and Nanomaterials, Neuroscience Area, SISSA, Trieste 34136, Italy.,Dept. Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Teresa Sorbo
- Laboratory of Neurons and Nanomaterials, Neuroscience Area, SISSA, Trieste 34136, Italy
| | - Francesco Paolo Ulloa Severino
- Laboratory of Bionanotechnologies, Neuroscience Area, SISSA, Trieste 34136, Italy.,Cell Biology Dept, Duke University Medical Center, Duke University, Durham NC-27710, USA
| | - Giovanni Provenzano
- Department of Cellular, Computational, and Integrative Biology (CIBIO), University of Trento, Trento 38123, Italy
| | - Manuela Allegra
- Neuroscience Institute, Neurophysiology Section, National Research Council (CNR), Pisa 56124, Italy.,Laboratory G5 Circuits Neuronaux, Institut Pasteur, Paris 75015, France
| | - Matteo Caleo
- Neuroscience Institute, Neurophysiology Section, National Research Council (CNR), Pisa 56124, Italy.,Department of Biomedical Sciences, University of Padua, Padua 35121, Italy
| | - Laura Ballerini
- Laboratory of Neurons and Nanomaterials, Neuroscience Area, SISSA, Trieste 34136, Italy
| | - Yuri Bozzi
- Neuroscience Institute, Neurophysiology Section, National Research Council (CNR), Pisa 56124, Italy.,Center for Mind/Brain Sciences, University of Trento, Trento 38068, Italy
| | - Antonello Mallamaci
- Laboratory of Cerebral Cortex Development, Neuroscience Area, SISSA, Trieste 34136, Italy
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13
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Biondi B, Kahaly GJ, Robertson RP. Thyroid Dysfunction and Diabetes Mellitus: Two Closely Associated Disorders. Endocr Rev 2019; 40:789-824. [PMID: 30649221 PMCID: PMC6507635 DOI: 10.1210/er.2018-00163] [Citation(s) in RCA: 232] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 10/15/2018] [Indexed: 12/13/2022]
Abstract
Thyroid dysfunction and diabetes mellitus are closely linked. Several studies have documented the increased prevalence of thyroid disorders in patients with diabetes mellitus and vice versa. This review critically discusses the different underlying mechanisms linking type 1 and 2 diabetes and thyroid dysfunction to demonstrate that the association of these two common disorders is unlikely a simple coincidence. We assess the current state of knowledge on the central and peripheral control of thyroid hormone on food intake and glucose and lipid metabolism in target tissues (such as liver, white and brown adipose tissue, pancreatic β cells, and skeletal muscle) to explain the mechanism linking overt and subclinical hypothyroidism to type 2 diabetes and metabolic syndrome. We also elucidate the common susceptibility genes and the pathogenetic mechanisms contributing to the autoimmune mechanism involved in the onset of type 1 diabetes mellitus and autoimmune thyroid disorders. An untreated thyroid dysfunction can impair the metabolic control of diabetic patients, and this association can have important repercussions on the outcome of both of these disorders. Therefore, we offer recommendations for the diagnosis, management, and screening of thyroid disorders in patients with diabetes mellitus, including the treatment of diabetic patients planning a pregnancy. We also discuss the major causes of failure to achieve an optimal management of thyroid dysfunction in diabetic patients and provide recommendations for assessing and treating these disorders during therapy with antidiabetic drugs. An algorithm for a correct approach of these disorders when linked is also provided.
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Affiliation(s)
- Bernadette Biondi
- Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy
| | - George J Kahaly
- Department of Medicine I, Johannes Gutenberg University Medical Center, Mainz, Germany
| | - R Paul Robertson
- Department of Medicine, Division of Endocrinology and Metabolism, University of Washington School of Medicine, Seattle, Washington.,Department of Pharmacology, University of Washington, Seattle, Washington
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14
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Li M, Chen Y, Jiang J, Lu Y, Song Z, Zhang S, Sun C, Ying H, Fan X, Song Y, Yang J, Zhao L. Elevated serum neuregulin 4 levels in patients with hyperthyroidism. Endocr Connect 2019; 8:728-735. [PMID: 31063974 PMCID: PMC6547303 DOI: 10.1530/ec-19-0175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 05/07/2019] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Recent studies have shown that neuregulin 4 (Nrg4), a member of the epidermal growth factor (EGF) family of extracellular ligands, plays an important role in the prevention of obesity, insulin resistance and nonalcoholic fatty liver disease (NAFLD). Considering that thyroid hormone (TH) has profound effects on whole-body energy metabolism, we speculate that circulating Nrg4 levels might be altered in patients with hyperthyroidism. DESIGN AND METHODS A total of 129 hyperthyroid patients and 100 healthy subjects were recruited. Of them, 39 hyperthyroid patients received thionamide treatment for 3 months until euthyroidism. Serum Nrg4 levels were determined using the ELISA method. To further confirm the relationship between TH and Nrg4, C57BL/6 mice were treated with T3 and quantitative real-time PCR was performed to detect Nrg4 gene expression. RESULTS Serum Nrg4 levels were significantly elevated in hyperthyroid patients as compared with normal controls (3.84 ± 1.63 vs 2.21 ± 1.04 ng/mL, P < 0.001). After achieving euthyroidism by thionamide treatment, serum Nrg4 levels dropped markedly from 3.57 ± 1.26 to 1.94 ± 0.72 ng/ml (P < 0.001). After adjustment for potential confounders, serum Nrg4 levels were independently associated with hyperthyroidism. The upregulation of Nrg4 expression in the livers and white adipose tissues by T3 was further confirmed by animal and cell culture experiments. CONCLUSIONS Serum Nrg4 levels were increased in patients with hyperthyroidism. The liver and white adipose tissue might be primary sources contributing to elevated serum Nrg4 concentrations.
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Affiliation(s)
- Min Li
- Department of Endocrinology and Metabolism, Fudan Institute of Metabolic Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ying Chen
- Department of Endocrinology and Metabolism, Fudan Institute of Metabolic Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jingjing Jiang
- Department of Endocrinology and Metabolism, Fudan Institute of Metabolic Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yan Lu
- Department of Endocrinology and Metabolism, Fudan Institute of Metabolic Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhiyi Song
- Department of Endocrinology and Metabolism, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shengjie Zhang
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Chao Sun
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Hao Ying
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Xiaofang Fan
- Department of Endocrinology and Metabolism, Minhang Branch, Zhongshan Hospital, Central Hospital of Minhang District, Shanghai Minhang Hospital, Fudan University, Shanghai, China
| | - Yuping Song
- Department of Endocrinology and Metabolism, Minhang Branch, Zhongshan Hospital, Central Hospital of Minhang District, Shanghai Minhang Hospital, Fudan University, Shanghai, China
- Correspondence should be addressed to Y Song or J Yang or L Zhao: or or
| | - Jialin Yang
- Department of Endocrinology and Metabolism, Minhang Branch, Zhongshan Hospital, Central Hospital of Minhang District, Shanghai Minhang Hospital, Fudan University, Shanghai, China
- Correspondence should be addressed to Y Song or J Yang or L Zhao: or or
| | - Lin Zhao
- Department of Endocrinology and Metabolism, Fudan Institute of Metabolic Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
- Correspondence should be addressed to Y Song or J Yang or L Zhao: or or
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15
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Lakshmana Perumal N, Selvi J, Sridharan K, Sahoo J, Kamalanathan S. Insulin Sensitivity and Beta-Cell Function in Graves' Disease and Their Changes with the Carbimazole-Induced Euthyroid State. Eur Thyroid J 2019; 8:59-63. [PMID: 31192143 PMCID: PMC6514524 DOI: 10.1159/000496924] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/14/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND AND OBJECTIVE Thyroid hormones play an important role in intermediate metabolism, and abnormal glucose tolerance is often observed in patients with hyperthyroidism. Several pathogenic mechanisms have been proposed as contributors. However, there is no conclusive evidence in the existing literature regarding the predominant underlying pathophysiology. Our objective was to determine the changes in insulin resistance parameters and beta-cell function in patients with Graves' disease following restoration of a euthyroid state. METHODOLOGY This was an observational study with a before-after study design. Forty-five treatment-naïve adults with Graves' diseases were included and 36 completed the study. An oral glucose tolerance test was performed at baseline and after 3 months of achieving a stable euthyroid state to assess glucose tolerance, insulin sensitivity, and beta-cell function. All patients were treated with antithyroid medication. The outcome measures studied were the Homeostasis Model Assessment-2 Insulin Resistance (HOMA2-IR), Matsuda index, and Insulin Secretion-Sensitivity Index (ISSI)-2. RESULTS Two-thirds of the patients had abnormal glucose tolerance at baseline. Among those with abnormal glucose tolerance at baseline, 34.7% had persistent abnormality during follow-up. During follow-up, no significant change was noted in the indices of insulin resistance. Patients with abnormal glucose tolerance had a significantly lower ISSI-2 index at baseline and it improved after achieving a euthyroid state. CONCLUSIONS Abnormal glucose tolerance is a significant metabolic consequence in patients with Graves' disease. Decreased beta-cell function was observed among those with abnormal glucose tolerance and it improved during follow-up. In a proportion of patients, abnormal glucose tolerance persisted after 3 months, emphasizing the need for continued follow-up.
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Affiliation(s)
| | | | | | | | - Sadishkumar Kamalanathan
- *Sadishkumar Kamalanathan, Additional Professor and Head, Department of Endocrinology and Metabolism, 4th Floor, Super Specialty Block, Puducherry 605006 (India), E-Mail
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16
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Insights into Transcriptional Regulation of Hepatic Glucose Production. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 318:203-53. [DOI: 10.1016/bs.ircmb.2015.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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17
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Sinha RA, Singh BK, Yen PM. Thyroid hormone regulation of hepatic lipid and carbohydrate metabolism. Trends Endocrinol Metab 2014; 25:538-45. [PMID: 25127738 DOI: 10.1016/j.tem.2014.07.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 06/21/2014] [Accepted: 07/07/2014] [Indexed: 02/07/2023]
Abstract
Thyroid hormone (TH) has important roles in regulating hepatic lipid, cholesterol, and glucose metabolism. Recent findings suggest that clinical conditions such as non-alcoholic fatty liver disease and type 2 diabetes mellitus, which are associated with dysregulated hepatic metabolism, may involve altered intracellular TH action. In addition, TH has key roles in lipophagy in lipid metabolism, mitochondrial quality control, and the regulation of metabolic genes. In this review, we discuss recent findings regarding the functions of TH in hepatic metabolism, the relationship between TH and metabolic disorders, and the potential therapeutic use of thyromimetics to treat metabolic dysfunction in the liver.
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Affiliation(s)
- Rohit A Sinha
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169547, Singapore
| | - Brijesh K Singh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169547, Singapore
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169547, Singapore; Sarah W. Stedman Nutrition and Metabolism Center, Departments of Medicine and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27705, USA.
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18
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Abstract
Thyroid hormone (TH) is required for normal development as well as regulating metabolism in the adult. The thyroid hormone receptor (TR) isoforms, α and β, are differentially expressed in tissues and have distinct roles in TH signaling. Local activation of thyroxine (T4), to the active form, triiodothyronine (T3), by 5'-deiodinase type 2 (D2) is a key mechanism of TH regulation of metabolism. D2 is expressed in the hypothalamus, white fat, brown adipose tissue (BAT), and skeletal muscle and is required for adaptive thermogenesis. The thyroid gland is regulated by thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH). In addition to TRH/TSH regulation by TH feedback, there is central modulation by nutritional signals, such as leptin, as well as peptides regulating appetite. The nutrient status of the cell provides feedback on TH signaling pathways through epigentic modification of histones. Integration of TH signaling with the adrenergic nervous system occurs peripherally, in liver, white fat, and BAT, but also centrally, in the hypothalamus. TR regulates cholesterol and carbohydrate metabolism through direct actions on gene expression as well as cross-talk with other nuclear receptors, including peroxisome proliferator-activated receptor (PPAR), liver X receptor (LXR), and bile acid signaling pathways. TH modulates hepatic insulin sensitivity, especially important for the suppression of hepatic gluconeogenesis. The role of TH in regulating metabolic pathways has led to several new therapeutic targets for metabolic disorders. Understanding the mechanisms and interactions of the various TH signaling pathways in metabolism will improve our likelihood of identifying effective and selective targets.
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19
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Thakran S, Sharma P, Attia RR, Hori RT, Deng X, Elam MB, Park EA. Role of sirtuin 1 in the regulation of hepatic gene expression by thyroid hormone. J Biol Chem 2012; 288:807-18. [PMID: 23209300 DOI: 10.1074/jbc.m112.437970] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sirtuin 1 (SIRT1) is a nuclear deacetylase that modulates lipid metabolism and enhances mitochondrial activity. SIRT1 targets multiple transcription factors and coactivators. Thyroid hormone (T(3)) stimulates the expression of hepatic genes involved in mitochondrial fatty acid oxidation and gluconeogenesis. We reported that T(3) induces genes for carnitine palmitoyltransferase (cpt1a), pyruvate dehydrogenase kinase 4 (pdk4), and phosphoenolpyruvate carboxykinase (pepck). SIRT1 increases the expression of these genes via the activation of several factors, including peroxisome proliferator-activated receptor α, estrogen-related receptor α, and peroxisome proliferator-activated receptor γ coactivator (PGC-1α). Previously, we reported that PGC-1α participates in the T(3) induction of cpt1a and pdk4 in the liver. Given the overlapping targets of T(3) and SIRT1, we investigated whether SIRT1 participated in the T(3) regulation of these genes. Resveratrol is a small phenolic compound whose actions include the activation of SIRT1. Addition of resveratrol increased the T(3) induction of the pdk4 and cpt1a genes in hepatocytes. Furthermore, expression of SIRT1 in hepatocytes mimicked resveratrol in the regulation of gene expression by T(3). The deacetylase activity of SIRT1 was required and PGC-1α was deacetylated following addition of T(3). We found that SIRT1 interacted directly with T(3) receptor (TRβ). Knockdown of SIRT1 decreased the T(3) induction of cpt1a and pdk4 and reduced the T(3) inhibition of sterol response element binding protein (srebp-1c) both in isolated hepatocytes and in rat liver. Our results indicate that SIRT1 contributes to the T(3) regulation of hepatic genes.
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Affiliation(s)
- Shalini Thakran
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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20
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Meyer zu Schwabedissen HE, Ware JA, Finkelstein D, Chaudhry AS, Lemay S, Leon-Ponte M, Strom SC, Zaher H, Schwarz UI, Freeman DJ, Schuetz EG, Tirona RG, Kim RB. Hepatic organic anion transporting polypeptide transporter and thyroid hormone receptor interplay determines cholesterol and glucose homeostasis. Hepatology 2011; 54:644-54. [PMID: 21538436 PMCID: PMC3164486 DOI: 10.1002/hep.24391] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 04/15/2011] [Indexed: 12/07/2022]
Abstract
UNLABELLED The role of organic anion transporting polypeptides (OATPs), particularly the members of OATP1B subfamily, in hepatocellular handling of endogenous and exogenous compounds is an important and emerging area of research. Using a mouse model lacking Slco1b2, the murine ortholog of the OATP1B subfamily, we have demonstrated previously that genetic ablation causes reduced hepatic clearance capacity for substrates. In this study, we focused on the physiological function of the hepatic OATP1B transporters. First, we studied the influence of the Oatp1b2 deletion on bile acid (BA) metabolism, showing that lack of the transporter results in a significantly reduced expression of Cyp7a1, the key enzyme of BA synthesis, resulting in elevated cholesterol levels after high dietary fat challenge. Furthermore, Slco1b2-/- mice exhibited delayed clearance after oral glucose challenge resulting from reduced hepatic glucose uptake. In addition to increased hepatic glycogen content, Slco1b2-/- mice exhibited reduced glucose output after pyruvate challenge. This is in accordance with reduced hepatic expression of phosphoenolpyruvate carboxykinase (PEPCK) in knockout mice. We show that this phenotype is due to the loss of liver-specific Oatp1b2-mediated hepatocellular thyroid hormone entry, which then leads to reduced transcriptional activation of target genes of hepatic thyroid hormone receptor (TR), including Cyp7a1 and Pepck but also Dio1 and Glut2. Importantly, we assessed human relevance using a cohort of archived human livers in which OATP1B1 expression was noted to be highly associated with TR target genes, especially for glucose facilitating transporter 2 (GLUT2). Furthermore, GLUT2 expression was significantly decreased in livers harboring a common genetic polymorphism in SLCO1B1. CONCLUSION Our findings reveal that OATP1B-mediated hepatic thyroid hormone entry is a key determinant of cholesterol and glucose homeostasis.
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Affiliation(s)
| | - Joseph A. Ware
- Pfizer Global Research and Development, Ann Arbor, MI, USA
| | - David Finkelstein
- Information Sciences Department, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Amarjit S. Chaudhry
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Sara Lemay
- Division of Clinical Pharmacology, Department of Medicine, The University of Western Ontario, London, ON, Canada
| | - Matilde Leon-Ponte
- Division of Clinical Pharmacology, Department of Medicine, The University of Western Ontario, London, ON, Canada
| | - Stephen C. Strom
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hani Zaher
- Pfizer Global Research and Development, Ann Arbor, MI, USA
| | - Ute I. Schwarz
- Division of Clinical Pharmacology, Department of Medicine, The University of Western Ontario, London, ON, Canada, Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada
| | - David J. Freeman
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada
| | - Erin G. Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Rommel G. Tirona
- Division of Clinical Pharmacology, Department of Medicine, The University of Western Ontario, London, ON, Canada, Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada
| | - Richard B. Kim
- Division of Clinical Pharmacology, Department of Medicine, The University of Western Ontario, London, ON, Canada, Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada
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21
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Attia RR, Sharma P, Janssen RC, Friedman JE, Deng X, Lee JS, Elam MB, Cook GA, Park EA. Regulation of pyruvate dehydrogenase kinase 4 (PDK4) by CCAAT/enhancer-binding protein beta (C/EBPbeta). J Biol Chem 2011; 286:23799-807. [PMID: 21586575 DOI: 10.1074/jbc.m111.246389] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The conversion of pyruvate to acetyl-CoA in mitochondria is catalyzed by the pyruvate dehydrogenase complex (PDC). Activity of PDC is inhibited by phosphorylation via the pyruvate dehydrogenase kinases (PDKs). Here, we examined the regulation of Pdk4 gene expression by the CCAAT/enhancer-binding protein β (C/EBPβ). C/EBPβ modulates the expression of multiple hepatic genes including those involved in metabolism, development, and inflammation. We found that C/EBPβ induced Pdk4 gene expression and decreased PDC activity. This transcriptional induction was mediated through two C/EBPβ binding sites in the Pdk4 promoter. C/EBPβ participates in the hormonal regulation of gluconeogenic genes. Previously, we reported that Pdk4 was induced by thyroid hormone (T(3)). Therefore, we investigated the role of C/EBPβ in the T(3) regulation of Pdk4. T(3) increased C/EBPβ abundance in primary rat hepatocytes. Knockdown of C/EBPβ with siRNA diminished the T(3) induction of the Pdk4 and carnitine palmitoyltransferase (Cpt1a) genes. CPT1a is an initiating step in the mitochondrial oxidation of long chain fatty acids. Our results indicate that C/EBPβ stimulates Pdk4 expression and participates in the T(3) induction of the Cpt1a and Pdk4 genes.
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Affiliation(s)
- Ramy R Attia
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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22
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STAT3/NF-κB interactions determine the level of haptoglobin expression in male rats exposed to dietary restriction and/or acute phase stimuli. Mol Biol Rep 2011; 39:167-76. [DOI: 10.1007/s11033-011-0722-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 04/23/2011] [Indexed: 10/18/2022]
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23
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Attia RR, Connnaughton S, Boone LR, Wang F, Elam MB, Ness GC, Cook GA, Park EA. Regulation of pyruvate dehydrogenase kinase 4 (PDK4) by thyroid hormone: role of the peroxisome proliferator-activated receptor gamma coactivator (PGC-1 alpha). J Biol Chem 2009; 285:2375-85. [PMID: 19948729 DOI: 10.1074/jbc.m109.039081] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PDK4 (pyruvate dehydrogenase kinase 4) regulates pyruvate oxidation through the phosphorylation and inhibition of the pyruvate dehydrogenase complex (PDC). PDC catalyzes the conversion of pyruvate to acetyl-CoA and is an important control point in glucose and pyruvate metabolism. PDK4 gene expression is stimulated by thyroid hormone (T(3)), glucocorticoids, and long chain fatty acids. The effects of T(3) on gene expression in the liver are mediated via the thyroid hormone receptor. Here, we have identified two binding sites for thyroid hormone receptor beta in the promoter of the rat PDK4 (rPDK4) gene. In addition, we have investigated the role of transcriptional coactivators and found that the PGC-1 alpha (peroxisome proliferator-activated receptor gamma coactivator) enhances the T(3) induction of rPDK4. Following T(3) administration, there is an increase in the association of PGC-1 alpha with the rPDK4 promoter. Interestingly, this increased association is with the proximal rPDK4 promoter rather than the distal region of the gene that contains the T(3) response elements. Administration of T(3) to hypothyroid rats elevated the abundance of PGC-1 alpha mRNA and protein in the liver. In addition, we observed greater association of PGC-1 alpha not only with the rPDK4 gene but also with phosphoenolpyruvate carboxykinase and CPT-1a (carnitine palmitoyltransferase 1a) genes. Knockdown of PGC-1 alpha in rat hepatocytes reduced the T(3) induction of PDK4, PEPCK, and CPT-1a genes. Our results indicate that T(3) regulates PGC-1 alpha abundance and association with hepatic genes, and in turn PGC-1 alpha is an important participant in the T(3) induction of selected genes.
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Affiliation(s)
- Ramy R Attia
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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24
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Wang H, Peiris TH, Mowery A, Le Lay J, Gao Y, Greenbaum LE. CCAAT/enhancer binding protein-beta is a transcriptional regulator of peroxisome-proliferator-activated receptor-gamma coactivator-1alpha in the regenerating liver. Mol Endocrinol 2008; 22:1596-605. [PMID: 18467525 DOI: 10.1210/me.2007-0388] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The transcriptional coactivator peroxisome-proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) is induced in the liver in response to fasting and coordinates the activation of targets necessary for increasing energy production for gluconeogenesis and ketogenesis. After partial hepatectomy, the liver must restore its mass while maintaining metabolic homeostasis to ensure survival. Here we report that PGC-1alpha is rapidly and dramatically induced after hepatectomy, with an amplitude of induction that exceeds the fasting response. Maximal activation of PGC-1alpha after hepatectomy is dependent on the basic leucine zipper transcription factor, CCAAT/enhancer binding protein-beta (C/EBPbeta), a critical factor in hepatocyte proliferation. We demonstrate in vivo C/EBPbeta binding to C/EBP and cAMP response element sites in the PGC-1alpha promoter and show that the C/EBP site is essential for PGC-1alpha activation. Expression of the PGC-1alpha target, carnitine palmitoyl transferase 1a, the rate-limiting enzyme in fatty acid beta-oxidation, and of long-chain acyl-coenzyme A dehydrogenase, an enzyme involved in beta-oxidation of long chain fatty acids, was significantly reduced in C/EBPbeta(-/-) livers after hepatectomy. These findings identify C/EBPbeta as a direct activator of PGC-1alpha in the regenerating liver. The demonstration of a functional link between C/EBPbeta and PGC-1alpha activation provides a likely mechanism for how upstream signaling pathways in the regenerating liver can enable the adaptation to the changed metabolic status.
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Affiliation(s)
- Haitao Wang
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Ghosh AK, Bhattacharyya S, Mori Y, Varga J. Inhibition of collagen gene expression by interferon-gamma: novel role of the CCAAT/enhancer binding protein beta (C/EBPbeta). J Cell Physiol 2006; 207:251-60. [PMID: 16331681 DOI: 10.1002/jcp.20559] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
By inhibiting collagen synthesis, interferon-gamma (IFN-gamma) plays a key role in maintaining connective tissue homeostasis, but the mechanisms are not well-understood. In addition to intracellular signaling through the canonical JAK-STAT transduction pathway, IFN-gamma was recently shown to regulate gene expression via the CCAAT/enhancer-binding protein beta (C/EBPbeta) as well. Because C/EBPbeta is a crucial mediator of immune and inflammatory responses, and has been implicated in regulation of collagen synthesis by tumor necrosis factor-alpha, we examined its role in the inhibitory effects of IFN-gamma. The results demonstrated that IFN-gamma caused increased C/EBPbeta expression in dermal fibroblasts and enhanced its binding to cognate DNA sequences in the alpha2(I) procollagen gene (COL1A2) promoter in vitro and in vivo. Disruption of C/EBP binding by deletion or site-directed mutagenesis abrogated the inhibition of collagen promoter activity in transient transfection assays, as did cotransfection with dominant negative C/EBPbeta, indicating a functional role of cellular C/EBPbeta in mediating the IFN-gamma response. Rapid phosphorylation of the ERK1/2 MAP kinases induced by IFN-gamma was accompanied by phosphorylation and nuclear translocation of cellular C/EBPbeta, and pretreatment of fibroblasts with ERK1/2 kinase inhibitor blocked C/EBPbeta phosphorylation, as well as inhibition of COL1A2 promoter activity, elicited by IFN-gamma. These results provide compelling evidence for a novel C/EBPbeta-dependent IFN-gamma signaling pathway responsible for inhibition of collagen gene transcription. Taken together with recent reports, the findings indicate that intracellular pathways mediating negative regulation of collagen synthesis in response to distinct inflammatory signals that converge on C/EBPbeta.
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Affiliation(s)
- Asish K Ghosh
- Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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McFie PJ, Wang GL, Timchenko NA, Wilson HL, Hu X, Roesler WJ. Identification of a Co-repressor That Inhibits the Transcriptional and Growth-Arrest Activities of CCAAT/Enhancer-binding Protein α. J Biol Chem 2006; 281:18069-80. [PMID: 16644732 DOI: 10.1074/jbc.m512734200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We used a yeast two-hybrid screening approach to identify novel interactors of CCAAT/enhancer-binding protein alpha (C/EBPalpha) that may offer insight into its mechanism of action and regulation. One clone obtained was that for CA150, a nuclear protein previously characterized as a transcriptional elongation factor. In this report, we show that CA150 is a widely expressed co-repressor of C/EBP proteins. Two-hybrid and co-immunoprecipitation analyses indicated that CA150 interacts with C/EBPalpha. Overexpression of CA150 inhibited the transactivation produced by C/EBPalpha and was also able to reverse the enhancing effect of the co-activator p300 on C/EBPbeta-mediated transactivation. Analysis of C/EBPalpha mutants indicated that CA150 interacts with C/EBPalpha primarily through a domain spanning amino acids 135-150. Chromatin immunoprecipitation assays showed that CA150 was present on a promoter that is repressed by C/EBPalpha but not present on a promoter that is activated by C/EBPalpha. Finally, we showed that in cells in which growth arrest had been induced by ectopic expression of C/EBPalpha, CA150 was able to release them from growth arrest. Interestingly, CA150 could not reverse the growth arrest produced by the minimal growth-arrest domain of C/EBPalpha (amino acids 175-217), suggesting that the effect of CA150 was directed at a region of C/EBPalpha outside of this minimal domain, consistent with our two-hybrid analysis. Taken together, these data indicate that CA150 is a co-repressor of C/EBP proteins and provides a possible mechanism for how C/EBPalpha can repress transcription of specific genes.
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Affiliation(s)
- Pamela J McFie
- Department of Biochemistry, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada
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Yin L, Wang Y, Dridi S, Vinson C, Hillgartner FB. Role of CCAAT/enhancer-binding protein, histone acetylation, and coactivator recruitment in the regulation of malic enzyme transcription by thyroid hormone. Mol Cell Endocrinol 2005; 245:43-52. [PMID: 16293364 DOI: 10.1016/j.mce.2005.10.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 10/07/2005] [Accepted: 10/11/2005] [Indexed: 11/23/2022]
Abstract
In chick embryo hepatocytes, activation of malic enzyme gene transcription by triiodothyronine (T3) is mediated by a T3 response unit (T3RU) that contains five T3 response elements (T3REs) plus five accessory elements that enhance T3 responsiveness conferred by the T3REs. Results from in vitro binding assays indicate that one of the accessory elements (region F) binds CCAAT/enhancer-binding protein-alpha (C/EBPalpha). Here, we investigated the role of C/EBPalpha in the regulation of malic enzyme transcription by T3. Transfection analyses demonstrated that the stimulation of T3RE function by region F did not require the presence of additional malic enzyme gene promoter sequences. Expression of a dominant negative C/EBP inhibited the ability of region F to stimulate T3 responsiveness. In chromatin immunoprecipitation assays, C/EBPalpha and TR associated with the malic enzyme T3RU in the absence and presence of T3 with the extent of the association being greater in the presence of T3. These observations indicate that C/EBPalpha interacts with TR on the malic enzyme T3RU to enhance T3 regulation of malic enzyme gene transcription. T3 treatment increased the acetylation of histones, decreased the recruitment of nuclear receptor corepressor and increased the recruitment of steroid receptor coactivator-1, CREB binding protein, and the thyroid hormone associated protein/mediator complex at the malic enzyme T3RU. In contrast, T3 treatment had no effect on the acetylation of histones and the recruitment of corepressors and coactivators at the T3RU that mediates the T3 activation of acetyl-CoA carboxylase-alpha gene transcription. We propose that differences between the malic enzyme T3RU and the ACCalpha T3RU in the ability of T3 to modulate histone acetylation and coregulatory protein recruitment are due to differences in the composition of the nuclear receptor complexes that bind these regulatory regions.
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Affiliation(s)
- Liya Yin
- Department of Biochemistry and Molecular Pharmacology, School of Medicine, P.O. Box 9142, West Virginia University, Morgantown, 26506-9142, USA
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Dhawan P, Peng X, Sutton ALM, MacDonald PN, Croniger CM, Trautwein C, Centrella M, McCarthy TL, Christakos S. Functional cooperation between CCAAT/enhancer-binding proteins and the vitamin D receptor in regulation of 25-hydroxyvitamin D3 24-hydroxylase. Mol Cell Biol 2005; 25:472-87. [PMID: 15601867 PMCID: PMC538756 DOI: 10.1128/mcb.25.1.472-487.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
1,25-Dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] induces the synthesis of 25-hydroxyvitamin D(3) 24-hydroxylase [24(OH)ase], an enzyme involved in its catabolism, thereby regulating its own metabolism. Here we demonstrate that CCAAT enhancer binding protein beta (C/EBPbeta) is induced by 1,25(OH)(2)D(3) in kidney and in osteoblastic cells and is a potent enhancer of vitamin D receptor (VDR)-mediated 24(OH)ase transcription. Transfection studies indicate that 1,25(OH)(2)D(3) induction of 24(OH)ase transcription is enhanced a maximum of 10-fold by C/EBPbeta. Suppression of 1,25(OH)(2)D(3)-induced 24(OH)ase transcription was observed with dominant negative C/EBP or osteoblastic cells from C/EBPbeta(-/-) mice. A C/EBP site was identified at positions -395 to -388 (-395/-388) in the rat 24(OH)ase promoter. Mutation of this site inhibited C/EBPbeta binding and markedly attenuated the transcriptional response to C/EBPbeta. We also report the cooperation of CBP/p300 with C/EBPbeta in regulating VDR-mediated 24(OH)ase transcription. We found that not only 1,25(OH)(2)D(3) but also parathyroid hormone (PTH) can induce C/EBPbeta expression in osteoblastic cells. PTH potentiated the induction of C/EBPbeta and 24(OH)ase expression in response to 1,25(OH)(2)D(3) in osteoblastic cells. Data with the human VDR promoter (which contains two putative C/EBP sites) indicate a role for C/EBPbeta in the protein kinase A-mediated induction of VDR transcription. From this study a fundamental role has been established for the first time for cooperative effects and cross talk between the C/EBP family of transcription factors and VDR in 1,25(OH)(2)D(3)-induced transcription. These findings also indicate a novel role for C/EBPbeta in the cross talk between PTH and 1,25(OH)(2)D(3) that involves the regulation of VDR transcription.
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Affiliation(s)
- Puneet Dhawan
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
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Gautier-Stein A, Mithieux G, Rajas F. A Distal Region Involving Hepatocyte Nuclear Factor 4α and CAAT/Enhancer Binding Protein Markedly Potentiates the Protein Kinase A Stimulation of the Glucose-6-Phosphatase Promoter. Mol Endocrinol 2005; 19:163-74. [PMID: 15388792 DOI: 10.1210/me.2004-0105] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
AbstractGlucose-6-phosphatase (Glc6Pase) is the last enzyme of gluconeogenesis and is only expressed in the liver, kidney, and small intestine. In these tissues, the mRNA and its activity are increased when cAMP levels increased (e.g. in fasting or diabetes). We first report that a proximal region (within −200 bp relative to the transcription start site) and a distal region (−694/−500 bp) are both required for a potent cAMP and a protein kinase A (PKA) responsiveness of the Glc6Pase promoter. Using different molecular approaches, we demonstrate that hepatocyte nuclear factor (HNF4α), CAAT/ enhancer-binding protein-α (C/EBPα), C/EBPβ, and cAMP response element-binding protein (CREB) are involved in the potentiated PKA responsiveness: in the distal region, via one HNF4α- and one C/EBP-binding sites, and in the proximal region, via two HNF4α and two CREB-binding sites. We also show that HNF4α, C/EBPα, and C/EBPβ are constitutively bound to the endogenous Glc6Pase gene, whereas CREB and CREB-binding protein (CBP) will be bound to the gene upon stimulation by cAMP. These data strongly suggest that the cAMP responsiveness of the Glc6Pase promoter requires a tight cooperation between a proximal and a distal region, which depends on the presence of several HNF4α-, C/EBP-, and CREB-binding sites, therefore involving an intricate association of hepatic and ubiquitous transcription factors.
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Affiliation(s)
- Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, Unité 449/Institut National de la Recherche Agronomique 1235/Université Claude Bernard Lyon 1, Insitut Fédératif de Recherche Laennec, 69372 Lyon cedex 08, France.
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30
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Yeagley D, Quinn PG. 3',5'-cyclic adenosine monophosphate response element-binding protein and CCAAT enhancer-binding protein are dispensable for insulin inhibition of phosphoenolpyruvate carboxykinase transcription and for its synergistic induction by protein kinase A and glucocorticoids. Mol Endocrinol 2004; 19:913-24. [PMID: 15604115 DOI: 10.1210/me.2004-0281] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Phosphoenolpyruvate carboxykinase (PEPCK) transcription is induced by cAMP/protein kinase A (PKA) and glucocorticoids [dexamethasone (Dex)] and is inhibited by insulin to regulate blood glucose. Recent reports suggested that CCAAT enhancer binding protein (C/EBP) binding to the PEPCK cAMP response element (CRE) plays a role in Dex induction and that insulin-induces inhibitory forms of C/EBPbeta to inhibit transcription. Here, we assessed the roles of CRE-binding protein (CREB) and C/EBP factors in mediating hormone-regulated transcription. Neither cAMP nor insulin regulated the phosphorylation of C/EBP. Cycloheximide did not block insulin inhibition, indicating that alternate translation of C/EBPbeta is not required. Dominant-negative CREB or C/EBP blocked induction by PKA, but neither affected regulation by Dex or insulin. Tethering the activation domains of CREB or C/EBP to a CRE-->Gal4 (G4) site mediated varying extents of basal and PKA-inducible activity, but neither activation domain affected induction by Dex or inhibition by insulin. Surprisingly, synergistic induction by PKA and Dex did not require the CRE and was unaffected by dominant-negative CREB or C/EBP. PKA and Dex also synergistically induced a minimal 3 x glucocorticoid response element promoter, but inhibited Dex induction of the mouse mammary tumor virus and IGF-binding protein 1 promoters, even though PKA alone did not regulate these promoters. These results suggest that PKA modifies the activity of other factors involved in Dex induction to mediate synergistic induction or inhibition in a promoter-specific manner. Our data indicate that the roles of CREB and C/EBP are restricted to mediating PEPCK induction by PKA, and that other factors mediate PEPCK induction by Dex, synergism between PKA and Dex, and inhibition by insulin.
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Affiliation(s)
- David Yeagley
- The Pennsylvania State University, College of Medicine, Department of Cellular and Molecular Physiology, C4718, 500 University Drive, Hershey, Pennsylvania 17033, USA
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31
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Fang HL, Abdolalipour M, Duanmu Z, Smigelski JR, Weckle A, Kocarek TA, Runge-Morris M. Regulation of glucocorticoid-inducible hydroxysteroid sulfotransferase (SULT2A-40/41) gene transcription in primary cultured rat hepatocytes: role of CCAAT/enhancer-binding protein liver-enriched transcription factors. Drug Metab Dispos 2004; 33:147-56. [PMID: 15502011 DOI: 10.1124/dmd.104.000281] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanism responsible for glucocorticoid receptor (GR)-mediated induction of rat hepatic hydroxysteroid sulfotransferase (SULT2A-40/41) gene transcription was investigated. We previously reported that the region of the SULT2A-40/41 5'-flanking region delimited by -158 to -77 nucleotides relative to the transcription start site was sufficient to support GR-inducible expression. This region of the SULT2A-40/41 gene does not contain a consensus glucocorticoid receptor-responsive element, but does contain two consensus sites for liver-enriched CCAAT/enhancer-binding protein (C/EBP) transcription factors. In the present study, incubation of primary cultured rat hepatocytes with a GR-activating concentration (10(-7) M) of a potent glucocorticoid, dexamethasone or triamcinolone acetonide (TA), rapidly produced increases in C/EBPalpha and C/EBPbeta nuclear protein contents, as measured by Western blot or in vitro DNA-binding activity analysis, that preceded increases in SULT2A-40/41 mRNA and protein levels. Transient cotransfection of SULT2A-40/41 reporter plasmids with a dominant negative C/EBP expression plasmid completely blocked TA-inducible SULT2A-40/41 reporter gene expression. Linker scanning and site-directed mutagenesis of the proximal SULT2A-40/41 5'-flanking region, complemented by in vitro DNA-binding analyses, indicated that the more distal C/EBP site was important for controlling SULT2A-40/41 promoter activity. These data support a role for GR-inducible C/EBPalpha and C/EBPbeta expression in the transactivation of hepatic SULT2A-40/41 expression.
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Affiliation(s)
- Hai-Lin Fang
- Institute of Environmental Health Sciences, Wayne State University, 2727 Second Avenue, Room 4000, Detroit, MI 48201, USA
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32
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Wilson HL, McFie PJ, Roesler WJ. Different transcription factor binding arrays modulate the cAMP responsivity of the phosphoenolpyruvate carboxykinase gene promoter. J Biol Chem 2002; 277:43895-902. [PMID: 12237288 DOI: 10.1074/jbc.m203169200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cAMP responsiveness of the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter is mediated by a cAMP response unit, which includes three CCAAT/enhancer-binding protein (C/EBPs) sites, and a cAMP response element (CRE). Because both the CRE-binding protein and several C/EBP isoforms can to bind to the CRE with similar affinity, a variety of transcription factor bindings arrays in the cAMP response unit are possible that may affect the protein kinase A (PKA) responsivity of the promoter. To explore this issue, we have designed PEPCK promoter variants that have the native cis-elements within the cAMP response unit replaced with one or more LexA- and/or GAL4-binding sites. We also engineered the corresponding C/EBP and CRE-binding protein chimeras, which have their basic region leucine zipper domains replaced with LexA or GAL4 DNA-binding domains. Using this approach, we have reconstituted the PKA responsiveness of permissive PEPCK promoters in hepatoma cells and have characterized the PKA responsivity of the promoter under defined transcription factor occupancy patterns. Furthermore, analysis of deletion mutants of C/EBPalpha indicated that the domains that mediate its constitutive and PKA-inducible activities vary depending on which cis-element it occupies on the PEPCK promoter. These results suggest that promoter context may influence which domains within a transcription factor are employed to mediate transactivation.
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Affiliation(s)
- Heather L Wilson
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Canada
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Kanda N, Watanabe S. Ketoconazole suppresses interleukin-4 plus anti-CD40-induced IgE class switching in surface IgE negative B cells from patients with atopic dermatitis. J Invest Dermatol 2002; 119:590-9. [PMID: 12230500 DOI: 10.1046/j.1523-1747.2002.01864.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We previously reported that antimycotic agent ketoconazole suppressed interleukin-4 production in T cells from patients with atopic dermatitis. We herein studied if ketoconazole may suppress B cell IgE class switching. Interleukin-4 plus anti-CD40-induced IgE secretion was enhanced in peripheral blood surface IgE- B cells from atopic dermatitis patients compared to those from normal donors, and the secretion was inhibited by ketoconazole. Ketoconazole suppressed interleukin-4 plus anti-CD40-induced germline and mature epsilon transcripts in surface IgE- B cells. Ketoconazole also inhibited interleukin-4 plus anti-CD40-induced activation of germline epsilon promoter in human Burkitt lymphoma Ramos cells. The regions -171/-155 bp containing CCAAT/enhancer-binding protein element and -155/-109 bp containing Stat6 and nuclear factor kappaB elements were required for the ketoconazole-induced inhibition of the germline epsilon promoter activity. Ketoconazole inhibited interleukin-4 plus anti-CD40-induced enhancer activities of CCAAT/enhancer-binding protein and nuclear factor kappaB, and those of composite elements of CCAAT/enhancer-binding protein/Stat6 or of Stat6/nuclear factor kappaB, but did not alter that of Stat6 in Ramos cells. cAMP analog reversed the inhibitory effects of ketoconazole on interleukin-4 plus anti-CD40-induced IgE secretion, germline and mature epsilon transcripts, and epsilon germline promoter activation. Interleukin-4 plus anti-CD40 increased intracellular cAMP by activating cAMP-synthesizing adenylate cyclase in surface IgE- B cells, and the increase was greater in the cells from atopic dermatitis patients than in those from normal donors. Ketoconazole suppressed interleukin-4 plus anti-CD40-induced activation of adenylate cyclase in surface IgE- B cells. These results suggest that ketoconazole may suppress interleukin-4 plus anti-CD40-induced B cell IgE class switching by inhibiting cAMP signal, and stress its prophylactic effects on allergic diseases.
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Affiliation(s)
- Naoko Kanda
- Department of Dermatology, Teikyo University, School of Medicine, Tokyo, Japan.
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34
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Jurado LA, Song S, Roesler WJ, Park EA. Conserved amino acids within CCAAT enhancer-binding proteins (C/EBP(alpha) and beta) regulate phosphoenolpyruvate carboxykinase (PEPCK) gene expression. J Biol Chem 2002; 277:27606-12. [PMID: 11997389 DOI: 10.1074/jbc.m201429200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thyroid hormone and cAMP stimulate transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK). CCAAT enhancer-binding proteins (C/EBP(alpha) and beta) are involved in multiple aspects of the nutritional, developmental and hormonal regulation of PEPCK gene expression. Previously, we have identified a thyroid hormone response element in the PEPCK promoter and demonstrated that C/EBP proteins bound to the P3(I) site are participants in the induction of PEPCK gene expression by thyroid hormone and cAMP. Here, we identify several peptide regions within the transactivation domain of C/EBP(alpha) that enhance the ability of T(3) to stimulate gene transcription. We also demonstrate that several conserved amino acids in the transactivation domain of C/EBP(alpha) and C/EBPbeta are required for the stimulation of basal gene expression and identify amino acids within C/EBPbeta that participate in the cAMP induction of the PEPCK gene. Finally, we show that the CREB-binding protein (CBP) enhanced the induction of PEPCK gene transcription by thyroid hormone and that CBP is associated with the PEPCK gene in vivo. Our results indicate that both C/EBP proteins and CBP participate in the regulation of PEPCK gene transcription by thyroid hormone.
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Affiliation(s)
- Luis A Jurado
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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35
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Yin L, Zhang Y, Hillgartner FB. Sterol regulatory element-binding protein-1 interacts with the nuclear thyroid hormone receptor to enhance acetyl-CoA carboxylase-alpha transcription in hepatocytes. J Biol Chem 2002; 277:19554-65. [PMID: 11907029 DOI: 10.1074/jbc.m111771200] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In previous work, we characterized a 3,5,3'-triiodothyronine response element (T3RE) in acetyl-CoA carboxylase-alpha (ACCalpha) promoter 2 that mediated 3,5,3'-triiodothyronine (T3) regulation of ACCalpha transcription in chick embryo hepatocytes. Sequence comparison analysis revealed the presence of sterol regulatory element-1 (SRE-1) located 5 bp downstream of the ACCalpha T3RE. Here, we investigated the role of this SRE-1 in modulating T3 regulation of ACCalpha transcription. Transfection analyses demonstrated that the SRE-1 enhanced T3-induced ACCalpha transcription by more than 2-fold in hepatocytes. The effect of the SRE-1 on T3 responsiveness required the presence of the T3RE in its native orientation. In pull-down experiments, the mature form of sterol regulatory element-binding protein-1 (SREBP-1) specifically bound the alpha-isoform of the nuclear T3 receptor (TR), and the presence of T3 enhanced this interaction. A region of TRalpha containing the DNA-binding domain plus flanking sequences (amino acids 21-157) was required for interaction with SREBP-1, and a region of SREBP-1 containing the basic helix-loop-helix-leucine zipper domain (amino acids 300-389) was required for interaction with TRalpha. In gel mobility shift experiments, TRalpha, retinoid X receptor-alpha, and mature SREBP-1 formed a tetrameric complex on a DNA probe containing the ACCalpha T3RE and SRE-1, and the presence of T3 enhanced the formation of this complex. Formation of the tetrameric complex stabilized the binding of SREBP-1 to the SRE-1. These results indicate that SREBP-1 directly interacts with TR-retinoid X receptor in an orientation-specific manner to enhance T3-induced ACCalpha transcription in hepatocytes. T3 regulation of ACCalpha transcription in nonhepatic cell cultures such as chick embryo fibroblasts is markedly reduced compared with that of chick embryo hepatocytes. Here, we also show that alterations in SREBP expression play a role in mediating cell type-dependent differences in T3 regulation of ACCalpha transcription.
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Affiliation(s)
- Liya Yin
- Department of Biochemistry and Molecular Pharmacology, School of Medicine, West Virginia University, Morgantown, West Virginia 26506, USA
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36
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Bini E, Blum P. Archaeal catabolite repression: a gene regulatory paradigm. ADVANCES IN APPLIED MICROBIOLOGY 2002; 50:339-66. [PMID: 11677688 DOI: 10.1016/s0065-2164(01)50009-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- E Bini
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588-0666, USA
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37
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Abstract
CCAAT/enhancer binding proteins (C/EBPs) are transcription factors that are enriched in tissues which play a central role in energy metabolism, such as adipose and liver. Structure/function analyses of these proteins have identified several transactivation domains, some of which can physically interact with general transcription factors present in the preinitiation complex. C/EBPs are generally considered to be constitutively-acting factors, unlike other transcription factors whose activities can be regulated by covalent modification, binding of a specific ligand, etc. However, studies of the regulatory property of the phosphoenolpyruvate carboxykinase gene promoter have uncovered a role for C/EBPs in mediating cAMP responsiveness, and identified specific domains within the proteins, which mediate this effect. Interestingly, a number of other gene promoters that are activated in response to cAMP also contain binding sites for C/EBP, and these binding sites are often located within the region of the promoter that is responsible for mediating the acute responsiveness to cAMP. The evidence presented in this review provides compelling support for the hypothesis that C/EBPs have both constitutive and cAMP-inducible activities, and should be considered as a cAMP-responsive nuclear regulator.
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Affiliation(s)
- Heather L Wilson
- Department of Biochemistry, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK, Canada S7N 5E5
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38
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Abstract
C/EBPs are a family of transcription factors that play important roles in energy metabolism. Although initially thought to be constitutive regulators of transcription, an increasing amount of evidence indicates that their transactivating capacity within the cell can be modulated by nutrients and hormones. There are several mechanisms whereby this occurs. First, hormones/nutrients are known to directly alter the expression of C/EBPs. Second, hormones/nutrients may cause an alteration in the phosphorylation state of C/EBPs, which can affect their DNA-binding activity or transactivating capacity. Third, C/EBPs can function as accessory factors on gene promoters within a hormone response unit, interacting with other transcription factors to enhance the degree of responsiveness to specific hormones. Given their role in regulating genes involved in a wide variety of metabolic events, advancing our understanding of the molecular mechanism of action of C/EBPs will undoubtedly further our appreciation for the role these transcription factors play in both health and disease.
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Affiliation(s)
- W J Roesler
- Department of Biochemistry, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E5.
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Liu X, Wall QT, Taylor L, Curthoys NP. C/EBPbeta contributes to cAMP-activated transcription of phosphoenolpyruvate carboxykinase in LLC-PK(1)-F+ cells. Am J Physiol Renal Physiol 2001; 281:F649-57. [PMID: 11553511 DOI: 10.1152/ajprenal.2001.281.4.f649] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Phosphoenolpyruvate carboxykinase (PEPCK) is a key regulatory enzyme in renal gluconeogenesis. Activation of various PEPCK(-2300)Luc reporter constructs in LLC-PK(1)-F+ cells, a gluconeogenic line of porcine renal proximal tubule-like cells, by protein kinase A (PKA) is mediated, in part, through the cAMP-response element (CRE)-1 of the PEPCK promoter. Incubation of a CRE-1 containing oligonucleotide with nuclear extracts from LLC-PK(1)-F+ cells produced multiple bands, all of which were blocked by antibodies that are specific for C/EBPbeta but not for C/EBPalpha or C/EBPdelta. Treatment of cells with cAMP did not affect the expression of C/EBPbeta, but the observed binding activity was increased nearly threefold. Mutation of CRE-1 to a Gal-4 binding site reduced the PKA-dependent activation of PEPCK(-2300)Luc to 40% of that observed with the wild-type construct. Coexpression of a chimeric protein containing a Gal-4 binding domain and the transactivation domain of C/EBPbeta, but not of C/EBPalpha or CRE binding protein (CREB), restored full activation by PKA. A deletion construct that lacks the activation domain of C/EBPbeta functions as a dominant negative inhibitor. Thus the binding of C/EBPbeta to the CRE-1 may contribute to the cAMP-dependent activation of the PEPCK promoter in kidney cells.
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Affiliation(s)
- X Liu
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
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40
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Yoon JC, Puigserver P, Chen G, Donovan J, Wu Z, Rhee J, Adelmant G, Stafford J, Kahn CR, Granner DK, Newgard CB, Spiegelman BM. Control of hepatic gluconeogenesis through the transcriptional coactivator PGC-1. Nature 2001; 413:131-8. [PMID: 11557972 DOI: 10.1038/35093050] [Citation(s) in RCA: 1409] [Impact Index Per Article: 61.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Blood glucose levels are maintained by the balance between glucose uptake by peripheral tissues and glucose secretion by the liver. Gluconeogenesis is strongly stimulated during fasting and is aberrantly activated in diabetes mellitus. Here we show that the transcriptional coactivator PGC-1 is strongly induced in liver in fasting mice and in three mouse models of insulin action deficiency: streptozotocin-induced diabetes, ob/ob genotype and liver insulin-receptor knockout. PGC-1 is induced synergistically in primary liver cultures by cyclic AMP and glucocorticoids. Adenoviral-mediated expression of PGC-1 in hepatocytes in culture or in vivo strongly activates an entire programme of key gluconeogenic enzymes, including phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase, leading to increased glucose output. Full transcriptional activation of the PEPCK promoter requires coactivation of the glucocorticoid receptor and the liver-enriched transcription factor HNF-4alpha (hepatic nuclear factor-4alpha) by PGC-1. These results implicate PGC-1 as a key modulator of hepatic gluconeogenesis and as a central target of the insulin-cAMP axis in liver.
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Affiliation(s)
- J C Yoon
- Dana-Farber Cancer Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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41
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Jacob KK, Stanley FM. Elk-1, C/EBPalpha, and Pit-1 confer an insulin-responsive phenotype on prolactin promoter expression in Chinese hamster ovary cells and define the factors required for insulin-increased transcription. J Biol Chem 2001; 276:24931-6. [PMID: 11340077 DOI: 10.1074/jbc.m102826200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcription factor(s) that mediate insulin-increased gene transcription are not well defined. These studies use phenotypic conversion of Rat2 and Chinese hamster ovary (CHO) cells with transcription factors to identify components required for regulation of prolactin promoter activity and its control by insulin. The pituitary-derived GH4 cells contain all of the transcription factors required for insulin-increased prolactin-chloramphenicol acetyltransferase (CAT) expression while HeLa cells require only Pit-1, a pituitary-specific factor. However, Rat2 and CHO cells require additional factors. We had determined previously that the transcription factor that mediates insulin-increased prolactin gene expression was likely an Ets-related protein. Elk-1 and Sap-1 were the only Ets-related transcription factors tested as chimeras with LexA DNA-binding domain that were able to mediate insulin-increased expression of a LexA-CAT reporter plasmid. Elk-1 and Sap-1 are expressed in GH4 and HeLa cells but Rat2 and CHO cells express Sap-1, but not Elk-1. Expression of Elk-1 made Rat2 cells (but not CHO cells) insulin responsive. C/EBPalpha also binds to the prolactin promoter at a sequence overlapping the binding site for Elk-1. Expression of both C/EBPalpha and Pit-1 in CHO cells is required for high basal transcription of prolactin-CAT. Expression of Elk-1 converts CHO cells into a phenotype in which prolactin gene expression is increased by insulin treatment. Finally, antisense mediated reduction of Elk-1 in GH4 cells decreased insulin-increased prolactin gene expression and confirmed the requirement for Elk-1 for insulin-increased prolactin gene expression. Thus, both C/EBPalpha and Pit-1 were required for high basal transcription while insulin sensitivity required Elk-1.
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Affiliation(s)
- K K Jacob
- Department of Medicine, New York University School of Medicine, 550 First Ave., New York, NY 10016, USA
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42
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Wilson HL, McFie PJ, Roesler WJ. Characterization of domains in C/EBPalpha that mediate its constitutive and cAMP-inducible activities. Mol Cell Endocrinol 2001; 181:27-34. [PMID: 11476938 DOI: 10.1016/s0303-7207(01)00540-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Structure/function analysis of CCAAT/enhancer binding proteins (C/EBP) alpha and beta have shown that they possess both constitutive and cAMP inducible activities. Three regions conserved between C/EBPalpha and beta were identified which lie within the cAMP inducible domains of each protein. Deletion analysis of these conserved regions within C/EBPalpha show that conserved region 2 plays a particularly critical role in mediating the PKA inducible activity of the protein, however, the constitutive activity of conserved region 2 depends on promoter context. This data supports previous findings that constitutive and cAMP responsiveness are mediated by domains of the protein that do not directly overlap, suggesting that they occur through distinct mechanisms.
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Affiliation(s)
- H L Wilson
- Department of Biochemistry, University of Saskatchewan, 107 Wiggins Road, Saskatoon, S7N 5E5, Saskatchewan, Canada
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Wang Y, Yin L, Hillgartner FB. The homeodomain proteins PBX and MEIS1 are accessory factors that enhance thyroid hormone regulation of the malic enzyme gene in hepatocytes. J Biol Chem 2001; 276:23838-48. [PMID: 11331288 DOI: 10.1074/jbc.m102166200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Triiodothyronine (T3) stimulates a robust increase (>40-fold) in transcription of the malic enzyme gene in chick embryo hepatocytes. Previous work has shown that optimal T3 regulation of malic enzyme transcription is dependent on the presence of an accessory element (designated as region E) that immediately flanks a cluster of five T3 response elements in the malic enzyme gene. Here, we have analyzed the binding of nuclear proteins to region E and investigated the mechanism by which region E enhances T3 responsiveness. In nuclear extracts from hepatocytes, region E binds heterodimeric complexes consisting of the homeodomain proteins PBX and MEIS1. Region E contains four consecutive PBX/MEIS1 half-sites. PBX-MEIS1 heterodimers bind the first and second half-sites, the third and fourth half-sites, and the first and fourth half-sites. The configuration conferring the greatest increase in T3 responsiveness consists of the first and fourth half-sites that are separated by 7 nucleotides. Stimulation of T3 response element functions by region E does not require the presence of additional malic enzyme sequences. In pull-down experiments, PBX1a and PBX1b specifically bind the nuclear T3 receptor-alpha, and this interaction is enhanced by the presence of T3. A T3 receptor-alpha region containing the DNA binding domain plus flanking sequences (amino acids 21-157) is necessary and sufficient for binding to PBX1a and PBX1b. These results indicate that PBX-MEIS1 complexes interact with nuclear T3 receptors to enhance T3 regulation of malic enzyme transcription in hepatocytes.
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Affiliation(s)
- Y Wang
- Department of Biochemistry, School of Medicine, West Virginia University, Morgantown, West Virginia 26506, USA
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Xu K, Yen T, Geczy CL. Il-10 up-regulates macrophage expression of the S100 protein S100A8. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:6358-66. [PMID: 11342660 DOI: 10.4049/jimmunol.166.10.6358] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The murine calcium binding protein S100A8 (A8) is a leukocyte chemoattractant, but high levels may be protective and scavenge hypochlorite. A8 is induced by LPS, IFN-gamma, and TNF in elicited macrophages. Th2 cytokines generally suppress proinflammatory gene expression, and IL-4 and IL-13 partially decreased A8 induction in macrophages and endothelial cells stimulated by LPS or IFN. In contrast, IL-10 synergized with LPS and IFN to increase mRNA levels > or =9-fold and secreted A8 levels approximately 4-fold. IL-10 decreased the optimal time of mRNA expression induced by LPS from 24 to 8 h. Blocking experiments indicated that endogenous IL-10 contributes to gene induction by LPS. Cooperation between IL-10 and LPS was not due to altered mRNA stability but was dependent on de novo protein synthesis. Transfection analysis with A8 luciferase constructs confirmed that synergy was due to increased transcription. The region of the promoter involved was localized to a 178-bp fragment flanking the transcription start site of the gene. This region was also responsible for the suppressive effects of IL-4 and IL-13. Forskolin, CTP-cAMP, and PGE(2) also enhanced LPS- and IFN-induced A8 mRNA, whereas indomethacin significantly reduced synergy between IL-10 and LPS. Mitogen-activated protein kinase/cyclooxygenase 2/cAMP pathways involving CCAAT-enhancing binding protein, located within the active promoter, may mediate A8 gene up-regulation in a manner mechanistically distinct to genes regulated by IL-10 via the STAT pathway. A8 exhibits pleiotropic effects, and the high levels secreted as a result of IL-10 synergy may regulate untoward inflammatory damage by virtue of its an antioxidant capacity.
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Affiliation(s)
- K Xu
- Cytokine Research Unit, School of Pathology, Faculty of Medicine, University of New South Wales, Sydney, Australia
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Ghosh AK, Lacson R, Liu P, Cichy SB, Danilkovich A, Guo S, Unterman TG. A nucleoprotein complex containing CCAAT/enhancer-binding protein beta interacts with an insulin response sequence in the insulin-like growth factor-binding protein-1 gene and contributes to insulin-regulated gene expression. J Biol Chem 2001; 276:8507-15. [PMID: 11116147 DOI: 10.1074/jbc.m008541200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Highly related insulin response sequences (IRSs) mediate effects of insulin on the expression of multiple genes in the liver, including insulin-like growth factor binding protein-1 (IGFBP-1) and phosphoenolpyruvate carboxykinase (PEPCK). Gel shift studies reveal that oligonucleotide probes containing an IRS from the IGFBP-1 or PEPCK gene form a similar complex with hepatic nuclear proteins. Unlabeled competitors containing the IGFBP-1 or PEPCK IRS or a binding site for C/EBP proteins inhibit the formation of this complex. Antibody against C/EBPbeta (but not other C/EBP proteins) supershifts this complex, and Western blotting of affinity purified proteins confirms that C/EBPbeta is present in this complex. Studies with affinity purified and recombinant protein indicate that C/EBPbeta does not interact directly with the IRS, but that other factors are required. Gel shift assays and reporter gene studies with constructs containing point mutations within the IRS reveal that the ability to interact with factors required for the formation of this complex correlates well with the ability of insulin to regulate promoter activity via this IRS (r = 0.849, p < 0.01). Replacing the IRS in reporter gene constructs with a C/EBP-binding site (but not an HNF-3/forkhead site or cAMP response element) maintains the effect of insulin on promoter activity. Together, these findings indicate that a nucleoprotein complex containing C/EBPbeta interacts with IRSs from the IGFBP-1 and PEPCK genes in a sequence-specific fashion and may contribute to the ability of insulin to regulate gene expression.
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Affiliation(s)
- A K Ghosh
- Departments of Medicine, and Physiology and Biophysics, University of Illinois at Chicago College of Medicine and Veterans Affairs Chicago Health Care System (West Side Division), Chicago, Illinois 60612, USA
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46
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Guo S, Cichy SB, He X, Yang Q, Ragland M, Ghosh AK, Johnson PF, Unterman TG. Insulin suppresses transactivation by CAAT/enhancer-binding proteins beta (C/EBPbeta). Signaling to p300/CREB-binding protein by protein kinase B disrupts interaction with the major activation domain of C/EBPbeta. J Biol Chem 2001; 276:8516-23. [PMID: 11116148 DOI: 10.1074/jbc.m008542200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CAAT/enhancer-binding proteins (C/EBPs) play an important role in the regulation of gene expression in insulin-responsive tissues. We have found that a complex containing C/EBPbeta interacts with an insulin response sequence in the insulin-like growth factor-binding protein-1 (IGFBP-1) gene and that a C/EBP-binding site can mediate effects of insulin on promoter activity. Here, we examined mechanisms mediating this effect of insulin. The ability of insulin to suppress promoter activity via a C/EBP-binding site is blocked by LY294002, a phosphatidylinositol 3-kinase inhibitor, but not by rapamycin, which blocks activation of p70(S6 kinase). Dominant negative phosphatidylinositol 3-kinase and protein kinase B (PKB) block the effect of insulin, while activated PKB suppresses promoter function via a C/EBP-binding site, mimicking the effect of insulin. Coexpression studies indicate that insulin and PKB suppress transactivation by C/EBPbeta, but not C/EBPalpha, and that N-terminal transactivation domains in C/EBPbeta are required. Studies with Gal4 fusion proteins reveal that insulin and PKB suppress transactivation by the major activation domain in C/EBPbeta (AD II), located between amino acids 31 and 83. Studies with E1A protein indicate that interaction with p300/CBP is required for transactivation by AD II and the effect of insulin and PKB. Based on a consensus sequence, we identified a PKB phosphorylation site (Ser(1834)) within the region of p300/CBP known to bind C/EBPbeta. Mammalian two-hybrid studies indicate that insulin and PKB disrupt interactions between this region of p300 and AD II and that Ser(1834) is critical for this effect. Signaling by PKB and phosphorylation of Ser(1834) may play an important role in modulating interactions between p300/CBP and transcription factors and mediate effects of insulin and related growth factors on gene expression.
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Affiliation(s)
- S Guo
- University of Illinois at Chicago College of Medicine and Veterans Affairs Chicago Health Care System, Chicago, Illinois 60612, USA
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47
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Abstract
The major transcriptional factors involved in the adipogenic process include proteins belonging to the CCAAT/enhancer binding protein family, peroxisome proliferator-activated receptor gamma, and adipocyte determination and differentiation dependent factor 1, also known as sterol regulatory element-binding protein 1. This process has been characterized with the aid of cell lines that represent various stages in the path of adipocyte commitment, ranging from pluripotent mesodermal fibroblasts to preadipocytes. Molecular analyses have led to a cascade model for adipogenesis based on timed expression of CCAAT/enhancer-binding proteins and peroxisome proliferator-activated receptor gamma. Gene targeting and transgenic-mouse technologies, which allow the manipulation of endogenous genes for these transcription factors, have also contributed to the understanding of adipogenesis. This review aims to integrate this information to gain an understanding of the transcriptional regulation of fat cell formation.
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Affiliation(s)
- S M Rangwala
- Departments of Medicine and Genetics and The Penn Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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48
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Croniger CM, Millward C, Yang J, Kawai Y, Arinze IJ, Liu S, Harada-Shiba M, Chakravarty K, Friedman JE, Poli V, Hanson RW. Mice with a deletion in the gene for CCAAT/enhancer-binding protein beta have an attenuated response to cAMP and impaired carbohydrate metabolism. J Biol Chem 2001; 276:629-38. [PMID: 11024029 DOI: 10.1074/jbc.m007576200] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fifty percent of the mice homozygous for a deletion in the gene for CCAAT/enhancer-binding protein beta (C/EBP beta-/- mice; B phenotype) die within 1 to 2 h after birth of hypoglycemia. They do not mobilize their hepatic glycogen or induce the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK). Administration of cAMP resulted in mobilization of glycogen, induction of PEPCK mRNA, and a normal blood glucose; these mice survived beyond 2 h postpartum. Adult C/EBP beta-/- mice (A phenotype) also had difficulty in maintaining blood glucose levels during starvation. Fasting these mice for 16 or 30 h resulted in lower levels of hepatic PEPCK mRNA, blood glucose, beta-hydroxybutyrate, blood urea nitrogen, and gluconeogenesis when compared with control mice. The concentration of hepatic cAMP in these mice was 50% of controls, but injection of theophylline, together with glucagon, resulted in a normal cAMP levels. Agonists (glucagon, epinephrine, and isoproterenol) and other effectors of activation of adenylyl cyclase were the same in liver membranes isolated from C/EBP beta-/- mice and littermates. The hepatic activity of cAMP-dependent protein kinase was 80% of wild type mice. There was a 79% increase in the concentration of RI alpha and 27% increase in RII alpha in the particulate fraction of the livers of C/EBP beta-/- mice relative to wild type mice, with no change in the catalytic subunit (C alpha). Thus, a 45% increase in hepatic cAMP (relative to the wild type) would be required in C/EBP beta-/- mice to activate protein kinase A by 50%. In addition, the total activity of phosphodiesterase in the livers of C/EBP beta-/- mice, as well as the concentration of mRNA for phosphodiesterase 3A (PDE3A) and PDE3B was approximately 25% higher than in control animals, suggesting accelerated degradation of cAMP. C/EBP beta influences the regulation of carbohydrate metabolism by altering the level of hepatic cAMP and the activity of protein kinase A.
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Affiliation(s)
- C M Croniger
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4935, USA.
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Waltner-Law M, Daniels MC, Sutherland C, Granner DK. NF-kappa B inhibits glucocorticoid and cAMP-mediated expression of the phosphoenolpyruvate carboxykinase gene. J Biol Chem 2000; 275:31847-56. [PMID: 10913132 DOI: 10.1074/jbc.m003656200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription of the phosphoenolpyruvate carboxykinase (PEPCK) gene is regulated by a variety of agents. Glucocorticoids, retinoic acid, and glucagon (via its second messenger, cAMP) stimulate PEPCK gene transcription, whereas insulin, phorbol esters, cytokines, and oxidative stress have an opposing effect. Stimulation of PEPCK gene expression has been extensively studied, and a number of important DNA elements and binding proteins that regulate the transcription of this gene have been identified. However, the mechanisms utilized to turn off expression of this gene are not well-defined. Many of the negative regulators of PEPCK gene transcription also stimulate the nuclear localization and activation of the transcription factor NF-kappaB, so we hypothesized that this factor could be involved in the repression of PEPCK gene expression. We find that the p65 subunit of NF-kappaB represses the increase of PEPCK gene transcription mediated by glucocorticoids and cAMP in a concentration-dependent manner. The mutation of an NF-kappaB binding element identified in the PEPCK gene promoter fails to abrogate this repression. Further analysis suggests that p65 represses PEPCK gene transcription through a protein.protein interaction with the coactivator, CREB binding protein.
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Affiliation(s)
- M Waltner-Law
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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50
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Yeagley D, Moll J, Vinson CA, Quinn PG. Characterization of elements mediating regulation of phosphoenolpyruvate carboxykinase gene transcription by protein kinase A and insulin. Identification of a distinct complex formed in cells that mediate insulin inhibition. J Biol Chem 2000; 275:17814-20. [PMID: 10748164 DOI: 10.1074/jbc.m909842199] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The in vivo pattern of induction of phosphoenolpyruvate carboxykinase (PEPCK) gene transcription by cAMP and its inhibition by insulin is reproduced in H4IIe cells and is mediated by a bipartite cAMP/insulin response unit (C/IRU) consisting of a cAMP response element (-95/-87) and an upstream enhancer, AC (-271/-225). Studies in HepG2 cells showed that binding of AP-1 and CAAT/enhancer-binding protein (C/EBP) to AC is required for induction by cAMP, but insulin did not inhibit cAMP-induced PEPCK expression in HepG2 cells. Binding of H4IIe nuclear proteins to an AC element probe was inhibited by antibodies or a consensus site for C/EBP, but not AP-1. Transfection with dominant negative bZIP factors, which prevent endogenous factors from binding to DNA, showed that elimination of cAMP regulatory element-binding protein CREB or C/EBP activity blocked induction by protein kinase A (PKA), whereas elimination of AP-1 activity had no effect. In addition, promoters with multiple CREB sites, or a single CREB site and multiple C/EBP sites, mediated PKA induction, but this was inhibited to no greater extent than basal activity was by insulin. These results indicate that an AC factor other than C/EBP must mediate insulin inhibition. An A-site probe (-265/-247) or a probe across the middle of the AC element (-256/-237) competed for complexes formed by factors other than AP-1 or C/EBP. However, analysis of competitor oligonucleotides and antibodies for candidate factors failed to identify other factors. Scanning mutations throughout the AC element interfered with induction but allowed us to define five overlapping sites for regulatory factors in AC and to design probes binding just one or two factors. Comparison of the protein-DNA complexes formed on these smaller probes revealed that a specific complex present in rat liver and H4IIe cell nuclear extracts differed from those formed by HepG2 cell nuclear extracts. Our results suggest that multiple factors binding the AC element of the C/IRU interact with each other and CREB to regulate PEPCK induction by cAMP and inhibition by insulin and that the unique factor expressed in H4IIe cells is a candidate for involvement in insulin regulation of PKA-induced PEPCK gene transcription.
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Affiliation(s)
- D Yeagley
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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