1
|
Hauck AK, Mehmood R, Carpenter BJ, Frankfurter MT, Tackenberg MC, Inoue SI, Krieg MK, Cassim Bawa FN, Midha MK, Zundell DM, Batmanov K, Lazar MA. Nuclear receptor corepressors non-canonically drive glucocorticoid receptor-dependent activation of hepatic gluconeogenesis. Nat Metab 2024; 6:825-836. [PMID: 38622413 DOI: 10.1038/s42255-024-01029-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 03/07/2024] [Indexed: 04/17/2024]
Abstract
Nuclear receptor corepressors (NCoRs) function in multiprotein complexes containing histone deacetylase 3 (HDAC3) to alter transcriptional output primarily through repressive chromatin remodelling at target loci1-5. In the liver, loss of HDAC3 causes a marked hepatosteatosis largely because of de-repression of genes involved in lipid metabolism6,7; however, the individual roles and contribution of other complex members to hepatic and systemic metabolic regulation are unclear. Here we show that adult loss of both NCoR1 and NCoR2 (double knockout (KO)) in hepatocytes phenocopied the hepatomegalic fatty liver phenotype of HDAC3 KO. In addition, double KO livers exhibited a dramatic reduction in glycogen storage and gluconeogenic gene expression that was not observed with hepatic KO of individual NCoRs or HDAC3, resulting in profound fasting hypoglycaemia. This surprising HDAC3-independent activation function of NCoR1 and NCoR2 is due to an unexpected loss of chromatin accessibility on deletion of NCoRs that prevented glucocorticoid receptor binding and stimulatory effect on gluconeogenic genes. These studies reveal an unanticipated, non-canonical activation function of NCoRs that is required for metabolic health.
Collapse
Affiliation(s)
- Amy K Hauck
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Rashid Mehmood
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bryce J Carpenter
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maxwell T Frankfurter
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael C Tackenberg
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Shin-Ichi Inoue
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maria K Krieg
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Fathima N Cassim Bawa
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mohit K Midha
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Delaine M Zundell
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kirill Batmanov
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
2
|
Hong SH, Castro G, Wang D, Nofsinger R, Kane M, Folias A, Atkins AR, Yu RT, Napoli JL, Sassone-Corsi P, de Rooij DG, Liddle C, Downes M, Evans RM. Targeting nuclear receptor corepressors for reversible male contraception. Proc Natl Acad Sci U S A 2024; 121:e2320129121. [PMID: 38377195 PMCID: PMC10907271 DOI: 10.1073/pnas.2320129121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/06/2024] [Indexed: 02/22/2024] Open
Abstract
Despite numerous female contraceptive options, nearly half of all pregnancies are unintended. Family planning choices for men are currently limited to unreliable condoms and invasive vasectomies with questionable reversibility. Here, we report the development of an oral contraceptive approach based on transcriptional disruption of cyclical gene expression patterns during spermatogenesis. Spermatogenesis involves a continuous series of self-renewal and differentiation programs of spermatogonial stem cells (SSCs) that is regulated by retinoic acid (RA)-dependent activation of receptors (RARs), which control target gene expression through association with corepressor proteins. We have found that the interaction between RAR and the corepressor silencing mediator of retinoid and thyroid hormone receptors (SMRT) is essential for spermatogenesis. In a genetically engineered mouse model that negates SMRT-RAR binding (SMRTmRID mice), the synchronized, cyclic expression of RAR-dependent genes along the seminiferous tubules is disrupted. Notably, the presence of an RA-resistant SSC population that survives RAR de-repression suggests that the infertility attributed to the loss of SMRT-mediated repression is reversible. Supporting this notion, we show that inhibiting the action of the SMRT complex with chronic, low-dose oral administration of a histone deacetylase inhibitor reversibly blocks spermatogenesis and fertility without affecting libido. This demonstration validates pharmacologic targeting of the SMRT repressor complex for non-hormonal male contraception.
Collapse
Affiliation(s)
- Suk-Hyun Hong
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Glenda Castro
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Dan Wang
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Russell Nofsinger
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Maureen Kane
- Department of Nutritional Sciences and Toxicology, The University of California, Berkeley, CA94720
| | - Alexandra Folias
- Department of Nutritional Sciences and Toxicology, The University of California, Berkeley, CA94720
| | - Annette R. Atkins
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Ruth T. Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Joseph L. Napoli
- Department of Nutritional Sciences and Toxicology, The University of California, Berkeley, CA94720
| | - Paolo Sassone-Corsi
- Department of Biological Chemistry, Center for Epigenetics and Metabolism, U1233 INSERM, University of California, Irvine, CA92697
| | - Dirk G. de Rooij
- Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CHUtrecht, The Netherlands
| | - Christopher Liddle
- Storr Liver Centre, The Westmead Institute for Medical Research and Sydney Medical School, University of Sydney, Westmead, NSW2145, Australia
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| | - Ronald M. Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA92037
| |
Collapse
|
3
|
Paluvai H, Shanmukha KD, Tyedmers J, Backs J. Insights into the function of HDAC3 and NCoR1/NCoR2 co-repressor complex in metabolic diseases. Front Mol Biosci 2023; 10:1190094. [PMID: 37674539 PMCID: PMC10477789 DOI: 10.3389/fmolb.2023.1190094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023] Open
Abstract
Histone deacetylase 3 (HDAC3) and nuclear receptor co-repressor (NCoR1/2) are epigenetic regulators that play a key role in gene expression and metabolism. HDAC3 is a class I histone deacetylase that functions as a transcriptional co-repressor, modulating gene expression by removing acetyl groups from histones and non-histone proteins. NCoR1, on the other hand, is a transcriptional co-repressor that interacts with nuclear hormone receptors, including peroxisome proliferator-activated receptor gamma (PPARγ) and liver X receptor (LXR), to regulate metabolic gene expression. Recent research has revealed a functional link between HDAC3 and NCoR1 in the regulation of metabolic gene expression. Genetic deletion of HDAC3 in mouse models has been shown to improve glucose intolerance and insulin sensitivity in the liver, skeletal muscle, and adipose tissue. Similarly, genetic deletion of NCoR1 has improved insulin resistance and reduced adiposity in mouse models. Dysregulation of this interaction has been associated with the development of cardio-metabolic diseases such as cardiovascular diseases, obesity and type 2 diabetes, suggesting that targeting this pathway may hold promise for the development of novel therapeutic interventions. In this review, we summarize the current understanding of individual functions of HDAC3 and NCoR1/2 and the co-repressor complex formation (HDAC3/NCoR1/2) in different metabolic tissues. Further studies are needed to thoroughly understand the mechanisms through which HDAC3, and NCoR1/2 govern metabolic processes and the implications for treating metabolic diseases.
Collapse
Affiliation(s)
- Harikrishnareddy Paluvai
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Kumar D. Shanmukha
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Jens Tyedmers
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Johannes Backs
- Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| |
Collapse
|
4
|
Haftorn KL, Romanowska J, Lee Y, Page CM, Magnus PM, Håberg SE, Bohlin J, Jugessur A, Denault WRP. Stability selection enhances feature selection and enables accurate prediction of gestational age using only five DNA methylation sites. Clin Epigenetics 2023; 15:114. [PMID: 37443060 PMCID: PMC10339624 DOI: 10.1186/s13148-023-01528-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND DNA methylation (DNAm) is robustly associated with chronological age in children and adults, and gestational age (GA) in newborns. This property has enabled the development of several epigenetic clocks that can accurately predict chronological age and GA. However, the lack of overlap in predictive CpGs across different epigenetic clocks remains elusive. Our main aim was therefore to identify and characterize CpGs that are stably predictive of GA. RESULTS We applied a statistical approach called 'stability selection' to DNAm data from 2138 newborns in the Norwegian Mother, Father, and Child Cohort study. Stability selection combines subsampling with variable selection to restrict the number of false discoveries in the set of selected variables. Twenty-four CpGs were identified as being stably predictive of GA. Intriguingly, only up to 10% of the CpGs in previous GA clocks were found to be stably selected. Based on these results, we used generalized additive model regression to develop a new GA clock consisting of only five CpGs, which showed a similar predictive performance as previous GA clocks (R2 = 0.674, median absolute deviation = 4.4 days). These CpGs were in or near genes and regulatory regions involved in immune responses, metabolism, and developmental processes. Furthermore, accounting for nonlinear associations improved prediction performance in preterm newborns. CONCLUSION We present a methodological framework for feature selection that is broadly applicable to any trait that can be predicted from DNAm data. We demonstrate its utility by identifying CpGs that are highly predictive of GA and present a new and highly performant GA clock based on only five CpGs that is more amenable to a clinical setting.
Collapse
Affiliation(s)
- Kristine L Haftorn
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway.
- Institute of Health and Society, University of Oslo, Oslo, Norway.
| | - Julia Romanowska
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Global Public Health and Primary Care, University of Bergen, 5020, Bergen, Norway
| | - Yunsung Lee
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Christian M Page
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Division for Mental and Physical Health, Department of Physical Health and Aging, Norwegian Institute of Public Health, Oslo, Norway
| | - Per M Magnus
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Siri E Håberg
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Jon Bohlin
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Division for Infection Control and Environmental Health, Department of Infectious Disease Epidemiology and Modelling, Norwegian Institute of Public Health, Oslo, Norway
| | - Astanand Jugessur
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Global Public Health and Primary Care, University of Bergen, 5020, Bergen, Norway
| | - William R P Denault
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
| |
Collapse
|
5
|
English J, Orofino J, Cederquist CT, Paul I, Li H, Auwerx J, Emili A, Belkina A, Cardamone D, Perissi V. GPS2-mediated regulation of the adipocyte secretome modulates adipose tissue remodeling at the onset of diet-induced obesity. Mol Metab 2023; 69:101682. [PMID: 36731652 PMCID: PMC9922684 DOI: 10.1016/j.molmet.2023.101682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 01/22/2023] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVE Dysfunctional, unhealthy expansion of white adipose tissue due to excess dietary intake is a process at the root of obesity and Type 2 Diabetes development. The objective of this study is to contribute to a better understanding of the underlying mechanism(s) regulating the early stages of adipose tissue expansion and adaptation to dietary stress due to an acute, high-fat diet (HFD) challenge, with a focus on the communication between adipocytes and other stromal cells. METHODS We profiled the early response to high-fat diet exposure in wildtype and adipocyte-specific GPS2-KO (GPS2-AKO) mice at the cellular, tissue and organismal level. A multi-pronged approach was employed to disentangle the complex cellular interactions dictating tissue remodeling, via single-cell RNA sequencing and FACS profiling of the stromal fraction, and semi-quantitative proteomics of the adipocyte-derived exosomal cargo after 5 weeks of HFD feeding. RESULTS Our results indicate that loss of GPS2 in mature adipocytes leads to impaired adaptation to the metabolic stress imposed by HFD feeding. GPS2-AKO mice are significantly more inflamed, insulin resistant, and obese, compared to the WT counterparts. At the cellular level, lack of GPS2 in adipocytes impacts upon other stromal populations, with both the eWAT and scWAT depots exhibiting changes in the immune and non-immune compartments that contribute to an increase in inflammatory and anti-adipogenic cell types. Our studies also revealed that adipocyte to stromal cell communication is facilitated by exosomes, and that transcriptional rewiring of the exosomal cargo is crucial for tissue remodeling. Loss of GPS2 results in increased expression of secreted factors promoting a TGFβ-driven fibrotic microenvironment favoring unhealthy tissue remodeling and expansion. CONCLUSIONS Adipocytes serve as an intercellular signaling hub, communicating with the stromal compartment via paracrine signaling. Our study highlights the importance of proper regulation of the 'secretome' released by energetically stressed adipocytes at the onset of obesity. Altered transcriptional regulation of factors secreted via adipocyte-derived exosomes (AdExos), in the absence of GPS2, contributes to the establishment of an anti-adipogenic, pro-fibrotic adipose tissue environment, and to hastened progression towards a metabolically dysfunctional phenotype.
Collapse
Affiliation(s)
- Justin English
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA; Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA.
| | - Joseph Orofino
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA.
| | - Carly T. Cederquist
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Indranil Paul
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA; Center for Network Systems Biology, Boston University, Boston, MA, USA.
| | - Hao Li
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
| | - Johan Auwerx
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
| | - Andrew Emili
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA; Center for Network Systems Biology, Boston University, Boston, MA, USA.
| | - Anna Belkina
- Flow Cytometry Core Facility, Boston University School of Medicine, Boston, MA, USA; Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA.
| | - Dafne Cardamone
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA.
| | - Valentina Perissi
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA; School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
| |
Collapse
|
6
|
Nuclear corepressor SMRT acts as a strong regulator of both β-oxidation and suppressor of fibrosis in the differentiation process of mouse skeletal muscle cells. PLoS One 2022; 17:e0277830. [PMID: 36454860 PMCID: PMC9714868 DOI: 10.1371/journal.pone.0277830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 11/03/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Silencing Mediator of Retinoid and Thyroid hormone receptors (SMRT; NCoR2) is a transcriptional corepressor (CoR) which has been recognized as an important player in the regulation of hepatic lipogenesis and in somatic development in mouse embryo. SMRT protein is also widely expressed in mouse connective tissues, for example adipocytes and muscle. We recently reported that mice with global deletion of SMRT develop significant obesity and muscle wasting which are independent from thyroid hormone (TH) signaling and thermogenesis. However, the tissue specific role of SMRT in skeletal muscle is still not clear. METHODS To clarify role of SMRT in muscle differentiation, we made myogenic C2C12 clones which lack SMRT protein (C2C12-SKO) by using CRISPR-Cas9. Wild-type C2C12 (C2C12-WT) and C2C12-SKO cells were cultured in differentiation medium, and the resulting gene and protein profiles were compared between the two cell lines both before and after differentiation. We also analyzed muscle tissues which were dissected from whole body SMRT knockout (KO) mice and their controls. RESULTS We found significant up-regulation of muscle specific β-oxidation markers; Peroxisome proliferator-activated receptor δ (PPARδ) and PPARγ coactivator-1α (PGC-1α) in the C2C12-SKO cells, suggesting that the cells had a similar gene profile to what is found in exercised rodent skeletal muscle. On the other hand, confocal microscopic analysis showed the significant loss of myotubes in C2C12-SKO cells similar to the morphology found in immature myoblasts. Proteomics analysis also confirmed that the C2C12-SKO cells had higher expression of markers of fibrosis (ex. Collagen1A1; COL1A1 and Fibroblast growth factor-2; FGF-2), indicating the up-regulation of Transforming growth factor-β (TGF-β) receptor signaling. Consistent with this, treatment with a specific TGF-β receptor inhibitor ameliorated both the defects in myotube differentiation and fibrosis. CONCLUSION Taken together, we demonstrate that SMRT functions as a pivotal transcriptional mediator for both β-oxidation and the prevention for the fibrosis via TGF-β receptor signaling in the differentiation of C2C12 myoblasts. In contrast to the results from C2C12 cells, SMRT does not appear to play a role in adult skeletal muscle of whole body SMRT KO mice. Thus, SMRT plays a significant role in the differentiation of myoblasts.
Collapse
|
7
|
Barilla S, Treuter E, Venteclef N. Transcriptional and epigenetic control of adipocyte remodeling during obesity. Obesity (Silver Spring) 2021; 29:2013-2025. [PMID: 34813171 DOI: 10.1002/oby.23248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/27/2021] [Accepted: 05/07/2021] [Indexed: 01/05/2023]
Abstract
The rising prevalence of obesity over the past decades coincides with the rising awareness that a detailed understanding of both adipose tissue biology and obesity-associated remodeling is crucial for developing therapeutic and preventive strategies. Substantial progress has been made in identifying the signaling pathways and transcriptional networks that orchestrate alterations of adipocyte gene expression linked to diverse phenotypes. Owing to recent advances in epigenomics, we also gained a better appreciation for the fact that different environmental cues can epigenetically reprogram adipocyte fate and function, mainly by altering DNA methylation and histone modification patterns. Intriguingly, it appears that transcription factors and chromatin-modifying coregulator complexes are the key regulatory components that coordinate both signaling-induced transcriptional and epigenetic alterations in adipocytes. In this review, we summarize and discuss current molecular insights into how these alterations and the involved regulatory components trigger adipogenesis and adipose tissue remodeling in response to energy surplus.
Collapse
Affiliation(s)
- Serena Barilla
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden
| | - Eckardt Treuter
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden
| | - Nicolas Venteclef
- Cordeliers Research Center, Inserm, University of Paris, IMMEDIAB Laboratory, Paris, France
- Inovarion, Paris, France
| |
Collapse
|
8
|
Nuclear CoRepressors, NCOR1 and SMRT, are required for maintaining systemic metabolic homeostasis. Mol Metab 2021; 53:101315. [PMID: 34390859 PMCID: PMC8429965 DOI: 10.1016/j.molmet.2021.101315] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/20/2021] [Accepted: 08/09/2021] [Indexed: 02/07/2023] Open
Abstract
Objective The nuclear receptor corepressor 1 (NCOR1) and the silencing mediator of retinoic acid and thyroid hormone (SMRT, also known as NCOR2) play critical and specific roles in nuclear receptor action. NCOR1, both in vitro and in vivo specifically regulates thyroid hormone (TH) action in the context of individual organs such as the liver, and systemically in the context of the hypothalamic-pituitary-thyroid (HPT) axis. In contrast, selective deletion of SMRT in the liver or globally has shown that it plays very little role in TH signaling. However, both NCOR1 and SMRT have some overlapping roles in hepatic metabolism and lipogenesis. Here, we determine the roles of NCOR1 and SMRT in global physiologic function and find if SMRT could play a compensatory role in the regulation of TH action, globally. Methods We used a postnatal deletion strategy to disrupt both NCOR1 and SMRT together in all tissues at 8–9 weeks of age in male and female mice. This was performed using a tamoxifen-inducible Cre recombinase (UBC-Cre-ERT2) to KO (knockout) NCOR1, SMRT, or NCOR1 and SMRT together. We used the same strategy to KO HDAC3 in male and female mice of the same age. Metabolic parameters, gene expression, and thyroid function tests were analyzed. Results Surprisingly, adult mice that acquired NCOR1 and SMRT deletion rapidly became hypoglycemic and hypothermic and perished within ten days of deletion of both corepressors. Postnatal deletion of either NCOR1 or SMRT had no impact on mortality. NCOR1/SMRT KO mice rapidly developed hepatosteatosis and mild elevations in liver function tests. Additionally, alterations in lipogenesis, beta oxidation, along with hepatic triglyceride and glycogen levels suggested defects in hepatic metabolism. The intestinal function was intact in the NCOR1/SMRT knockout (KO) mice. The KO of HDAC3 resulted in a distinct phenotype from the NCOR1/SMRT KO mice, whereas none of the HDAC3 KO mice succumbed after tamoxifen injection. Conclusions The KO of NCOR1 and SMRT rapidly leads to significant metabolic abnormalities that do not survive – including hypoglycemia, hypothermia, and weight loss. Hepatosteatosis rapidly developed along with alterations in hepatic metabolism suggesting a contribution to the dramatic phenotype from liver injury. Glucose production and absorption were intact in NCOR1/SMRT KO mice, demonstrating a multifactorial process leading to their demise. HDAC3 KO mice have a distinct phenotype from the NCOR1/SMRT KO mice—which implies that NCOR1/SMRT together regulate a critical pathway that is required for survival in adulthood and is separate from HDAC3. The knockout of corepressors NCoR1 and SMRT is rapidly lethal. Metabolic abnormalities observed include hypoglycemia and hypothermia. Hepatic glucose production and intestinal absorption is intact despite hypoglycemia. The lethal action of NCoR1/SMRT deletion is independent of HDAC3.
Collapse
|
9
|
Chao Y, Jiang Y, Zhong M, Wei K, Hu C, Qin Y, Zuo Y, Yang L, Shen Z, Zou C. Regulatory roles and mechanisms of alternative RNA splicing in adipogenesis and human metabolic health. Cell Biosci 2021; 11:66. [PMID: 33795017 PMCID: PMC8017860 DOI: 10.1186/s13578-021-00581-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/24/2021] [Indexed: 12/15/2022] Open
Abstract
Alternative splicing (AS) regulates gene expression patterns at the post-transcriptional level and generates a striking expansion of coding capacities of genomes and cellular protein diversity. RNA splicing could undergo modulation and close interaction with genetic and epigenetic machinery. Notably, during the adipogenesis processes of white, brown and beige adipocytes, AS tightly interplays with the differentiation gene program networks. Here, we integrate the available findings on specific splicing events and distinct functions of different splicing regulators as examples to highlight the directive biological contribution of AS mechanism in adipogenesis and adipocyte biology. Furthermore, accumulating evidence has suggested that mutations and/or altered expression in splicing regulators and aberrant splicing alterations in the obesity-associated genes are often linked to humans’ diet-induced obesity and metabolic dysregulation phenotypes. Therefore, significant attempts have been finally made to overview novel detailed discussion on the prospects of splicing machinery with obesity and metabolic disorders to supply featured potential management mechanisms in clinical applicability for obesity treatment strategies.
Collapse
Affiliation(s)
- Yunqi Chao
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Yonghui Jiang
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Mianling Zhong
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Kaiyan Wei
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Chenxi Hu
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Yifang Qin
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Yiming Zuo
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Lili Yang
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Zheng Shen
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China
| | - Chaochun Zou
- Department of Endocrinology, The Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310052, Zhejiang, China.
| |
Collapse
|
10
|
Chakraborty S, Ong WK, Yau WWY, Zhou Z, Bhanu Prakash KN, Toh SA, Han W, Yen PM, Sugii S. CD10 marks non-canonical PPARγ-independent adipocyte maturation and browning potential of adipose-derived stem cells. Stem Cell Res Ther 2021; 12:109. [PMID: 33541392 PMCID: PMC7863460 DOI: 10.1186/s13287-021-02179-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/20/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Effective stem cell therapy is dependent on the stem cell quality that is determined by their differentiation potential, impairment of which leads to poor engraftment and survival into the target cells. However, limitations in our understanding and the lack of reliable markers that can predict their maturation efficacies have hindered the development of stem cells as an effective therapeutic strategy. Our previous study identified CD10, a pro-adipogenic, depot-specific prospective cell surface marker of human adipose-derived stem cells (ASCs). Here, we aim to determine if CD10 can be used as a prospective marker to predict mature adipocyte quality and play a direct role in adipocyte maturation. METHODS We first generated 14 primary human subject-derived ASCs and stable immortalized CD10 knockdown and overexpression lines for 4 subjects by the lentiviral transduction system. To evaluate the role of CD10 in adipogenesis, the adipogenic potential of the human subject samples were scored against their respective CD10 transcript levels. Assessment of UCP1 expression levels was performed to correlate CD10 levels to the browning potential of mature ASCs. Quantitative polymerase chain reaction (qPCR) and Western blot analysis were performed to determine CD10-dependent regulation of various targets. Seahorse analysis of oxidative metabolism and lipolysis assay were studied. Lastly, as a proof-of-concept study, we used CD10 as a prospective marker for screening nuclear receptor ligands library. RESULTS We identified intrinsic CD10 levels as a positive determinant of adipocyte maturation as well as browning potential of ASCs. Interestingly, CD10 regulates ASC's adipogenic maturation non-canonically by modulating endogenous lipolysis without affecting the classical peroxisome proliferator-activated receptor gamma (PPARγ)-dependent adipogenic pathways. Furthermore, our CD10-mediated screening analysis identified dexamethasone and retinoic acid as stimulator and inhibitor of adipogenesis, respectively, indicating CD10 as a useful biomarker for pro-adipogenic drug screening. CONCLUSION Overall, we establish CD10 as a functionally relevant ASC biomarker, which may be a prerequisite to identify high-quality cell populations for improving metabolic diseases.
Collapse
Affiliation(s)
- Smarajit Chakraborty
- Fat Metabolism and Stem Cell Group, Singapore Bioimaging Consortium (SBIC), Agency for Science, Technology and Research (A*STAR) Singapore, 11 Biopolis Way, Singapore, 138667, Singapore
- Xenobiology Division, Institute of Bioengineering and Nanotechnology (IBN) Singapore, A*STAR, 31 Biopolis Way, Singapore, 138669, Singapore
| | - Wee Kiat Ong
- Fat Metabolism and Stem Cell Group, Singapore Bioimaging Consortium (SBIC), Agency for Science, Technology and Research (A*STAR) Singapore, 11 Biopolis Way, Singapore, 138667, Singapore
- School of Pharmacy, Monash University Malaysia, 47500, Selangor, Malaysia
| | - Winifred W Y Yau
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857, Singapore
| | - Zhihong Zhou
- Fat Metabolism and Stem Cell Group, Singapore Bioimaging Consortium (SBIC), Agency for Science, Technology and Research (A*STAR) Singapore, 11 Biopolis Way, Singapore, 138667, Singapore
| | - K N Bhanu Prakash
- Signal and Image Processing Group, SBIC, A*STAR Singapore, 11 Biopolis Way, Singapore, 138667, Singapore
| | - Sue-Anne Toh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Weiping Han
- Laboratory of Metabolic Medicine, SBIC, A*STAR Singapore, 11 Biopolis Way, Singapore, 138667, Singapore
| | - Paul M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857, Singapore
| | - Shigeki Sugii
- Fat Metabolism and Stem Cell Group, Singapore Bioimaging Consortium (SBIC), Agency for Science, Technology and Research (A*STAR) Singapore, 11 Biopolis Way, Singapore, 138667, Singapore.
- Xenobiology Division, Institute of Bioengineering and Nanotechnology (IBN) Singapore, A*STAR, 31 Biopolis Way, Singapore, 138669, Singapore.
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857, Singapore.
| |
Collapse
|
11
|
An S, Kim G, Kim HJ, Ahn S, Kim HY, Ko H, Hyun YE, Nguyen M, Jeong J, Liu Z, Han J, Choi H, Yu J, Kim JW, Lee HW, Jacobson KA, Cho WJ, Kim YM, Kang KW, Noh M, Jeong LS. Discovery and Structure-Activity Relationships of Novel Template, Truncated 1'-Homologated Adenosine Derivatives as Pure Dual PPARγ/δ Modulators. J Med Chem 2020; 63:16012-16027. [PMID: 33325691 DOI: 10.1021/acs.jmedchem.0c01874] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Following our report that A3 adenosine receptor (AR) antagonist 1 exhibited a polypharmacological profile as a dual modulator of peroxisome proliferator-activated receptor (PPAR)γ/δ, we discovered a new template, 1'-homologated adenosine analogues 4a-4t, as dual PPARγ/δ modulators without AR binding. Removal of binding affinity to A3AR was achieved by 1'-homologation, and PPARγ/δ dual modulation was derived from the structural similarity between the target nucleosides and PPAR modulator drug, rosiglitazone. All the final nucleosides were devoid of AR-binding affinity and exhibited high binding affinities to PPARγ/δ but lacked PPARα binding. 2-Cl derivatives exhibited dual receptor-binding affinity to PPARγ/δ, which was absent for the corresponding 2-H derivatives. 2-Propynyl substitution prevented PPARδ-binding affinity but preserved PPARγ affinity, indicating that the C2 position defines a pharmacophore for selective PPARγ ligand designs. PPARγ/δ dual modulators functioning as both PPARγ partial agonists and PPARδ antagonists promoted adiponectin production, suggesting their therapeutic potential against hypoadiponectinemia-associated cancer and metabolic diseases.
Collapse
Affiliation(s)
- Seungchan An
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,Natural Products Research Institute, Seoul National University, Seoul 08826, Korea
| | - Gyudong Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 61186, Korea
| | - Hyun Jin Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Sungjin Ahn
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,Natural Products Research Institute, Seoul National University, Seoul 08826, Korea
| | - Hyun Young Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Hyejin Ko
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,Natural Products Research Institute, Seoul National University, Seoul 08826, Korea
| | - Young Eum Hyun
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Mai Nguyen
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 61186, Korea
| | - Juri Jeong
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 61186, Korea
| | - Zijing Liu
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 61186, Korea
| | - Jinhe Han
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 61186, Korea
| | - Hongseok Choi
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Jinha Yu
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Ji Won Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Hyuk Woo Lee
- Future Medicine Company Ltd., Seongnam, Gyeonggi-do 13449, Korea
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, and Digestive and Kidney Disease, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Won Jea Cho
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 61186, Korea
| | - Young-Mi Kim
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Gyeonggi-do 15588, Korea
| | - Keon Wook Kang
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| | - Minsoo Noh
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.,Natural Products Research Institute, Seoul National University, Seoul 08826, Korea
| | - Lak Shin Jeong
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea
| |
Collapse
|
12
|
Goodson ML, Knotts TA, Campbell EL, Snyder CA, Young BM, Privalsky ML. Specific ablation of the NCoR corepressor δ splice variant reveals alternative RNA splicing as a key regulator of hepatic metabolism. PLoS One 2020; 15:e0241238. [PMID: 33104749 PMCID: PMC7588069 DOI: 10.1371/journal.pone.0241238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/10/2020] [Indexed: 12/15/2022] Open
Abstract
The NCoR corepressor plays critical roles in mediating transcriptional repression by both nuclear receptors and non-receptor transcription factors. Alternative mRNA splicing of NCoR produces a series of variants with differing molecular and biological properties. The NCoRω splice-variant inhibits adipogenesis whereas the NCoRδ splice-variant promotes it, and mice bearing a splice-specific knockout of NCoRω display enhanced hepatic steatosis and overall weight gain on a high fat diet as well as a greatly increased resistance to diet-induced glucose intolerance. We report here that the reciprocal NCoRδ splice-specific knock-out mice display the contrary phenotypes of reduced hepatic steatosis and reduced weight gain relative to the NCoRω-/- mice. The NCoRδ-/- mice also fail to demonstrate the strong resistance to diet-induced glucose intolerance exhibited by the NCoRω-/- animals. The NCoR δ and ω variants possess both unique and shared transcriptional targets, with expression of certain hepatic genes affected in opposite directions in the two mutants, others altered in one but not the other genotype, and yet others changed in parallel in both NCoRδ-/- and NCoRω-/- animals versus WT. Gene set expression analysis (GSEA) identified a series of lipid, carbohydrate, and amino acid metabolic pathways that are likely to contribute to their distinct steatosis and glucose tolerance phenotypes. We conclude that alternative-splicing of the NCoR corepressor plays a key role in the regulation of hepatic energy storage and utilization, with the NCoRδ and NCoRω variants exerting both opposing and shared functions in many aspects of this phenomenon and in the organism as a whole.
Collapse
Affiliation(s)
- Michael L. Goodson
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
- * E-mail:
| | - Trina A. Knotts
- Department of Molecular Biosciences, School of Veterinary Medicine and Mouse Metabolic Phenotyping Center, Microbiome & Host Response Core, University of California at Davis, Davis, California, United States of America
| | - Elsie L. Campbell
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| | - Chelsea A. Snyder
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| | - Briana M. Young
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| | - Martin L. Privalsky
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| |
Collapse
|
13
|
Kahn JH, Goddi A, Sharma A, Heiman J, Carmona A, Li Y, Hoffman A, Schoenfelt K, Ye H, Bobe AM, Becker L, Hollenberg AN, Cohen RN. SMRT Regulates Metabolic Homeostasis and Adipose Tissue Macrophage Phenotypes in Tandem. Endocrinology 2020; 161:bqaa132. [PMID: 32770234 PMCID: PMC7478322 DOI: 10.1210/endocr/bqaa132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 07/30/2020] [Indexed: 12/17/2022]
Abstract
The Silencing Mediator of Retinoid and Thyroid Hormone Receptors (SMRT) is a nuclear corepressor, regulating the transcriptional activity of many transcription factors critical for metabolic processes. While the importance of the role of SMRT in the adipocyte has been well-established, our comprehensive understanding of its in vivo function in the context of homeostatic maintenance is limited due to contradictory phenotypes yielded by prior generalized knockout mouse models. Multiple such models agree that SMRT deficiency leads to increased adiposity, although the effects of SMRT loss on glucose tolerance and insulin sensitivity have been variable. We therefore generated an adipocyte-specific SMRT knockout (adSMRT-/-) mouse to more clearly define the metabolic contributions of SMRT. In doing so, we found that SMRT deletion in the adipocyte does not cause obesity-even when mice are challenged with a high-fat diet. This suggests that adiposity phenotypes of previously described models were due to effects of SMRT loss beyond the adipocyte. However, an adipocyte-specific SMRT deficiency still led to dramatic effects on systemic glucose tolerance and adipocyte insulin sensitivity, impairing both. This metabolically deleterious outcome was coupled with a surprising immune phenotype, wherein most genes differentially expressed in the adipose tissue of adSMRT-/- mice were upregulated in pro-inflammatory pathways. Flow cytometry and conditioned media experiments demonstrated that secreted factors from knockout adipose tissue strongly informed resident macrophages to develop a pro-inflammatory, MMe (metabolically activated) phenotype. Together, these studies suggest a novel role for SMRT as an integrator of metabolic and inflammatory signals to maintain physiological homeostasis.
Collapse
Affiliation(s)
- Jonathan H Kahn
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Anna Goddi
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Aishwarya Sharma
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Joshua Heiman
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Alanis Carmona
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Yan Li
- Center for Research Informatics, University of Chicago, Chicago, Illinois
| | - Alexandria Hoffman
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Kelly Schoenfelt
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Honggang Ye
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Alexandria M Bobe
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Lev Becker
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | | | - Ronald N Cohen
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
- Department of Medicine, University of Chicago, Chicago, Illinois
- Section of Endocrinology, Diabetes, and Metabolism; University of Chicago, Chicago, Illinois
| |
Collapse
|
14
|
Barilla S, Liang N, Mileti E, Ballaire R, Lhomme M, Ponnaiah M, Lemoine S, Soprani A, Gautier JF, Amri EZ, Le Goff W, Venteclef N, Treuter E. Loss of G protein pathway suppressor 2 in human adipocytes triggers lipid remodeling by upregulating ATP binding cassette subfamily G member 1. Mol Metab 2020; 42:101066. [PMID: 32798719 PMCID: PMC7509237 DOI: 10.1016/j.molmet.2020.101066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/05/2020] [Accepted: 08/11/2020] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Adipogenesis is critical for adipose tissue remodeling during the development of obesity. While the role of transcription factors in the orchestration of adipogenic pathways is already established, the involvement of coregulators that transduce regulatory signals into epigenome alterations and transcriptional responses remains poorly understood. The aim of our study was to investigate which pathways are controlled by G protein pathway suppressor 2 (GPS2) during the differentiation of human adipocytes. METHODS We generated a unique loss-of-function model by RNAi depletion of GPS2 in human multipotent adipose-derived stem (hMADS) cells. We thoroughly characterized the coregulator depletion-dependent pathway alterations during adipocyte differentiation at the level of transcriptome (RNA-seq), epigenome (ChIP-seq H3K27ac), cistrome (ChIP-seq GPS2), and lipidome. We validated the in vivo relevance of the identified pathways in non-diabetic and diabetic obese patients. RESULTS The loss of GPS2 triggers the reprogramming of cellular processes related to adipocyte differentiation by increasing the responses to the adipogenic cocktail. In particular, GPS2 depletion increases the expression of BMP4, an important trigger for the commitment of fibroblast-like progenitors toward the adipogenic lineage and increases the expression of inflammatory and metabolic genes. GPS2-depleted human adipocytes are characterized by hypertrophy, triglyceride and phospholipid accumulation, and sphingomyelin depletion. These changes are likely a consequence of the increased expression of ATP-binding cassette subfamily G member 1 (ABCG1) that mediates sphingomyelin efflux from adipocytes and modulates lipoprotein lipase (LPL) activity. We identify ABCG1 as a direct transcriptional target, as GPS2 depletion leads to coordinated changes of transcription and H3K27 acetylation at promoters and enhancers that are occupied by GPS2 in wild-type adipocytes. We find that in omental adipose tissue of obese humans, GPS2 levels correlate with ABCG1 levels, type 2 diabetic status, and lipid metabolic status, supporting the in vivo relevance of the hMADS cell-derived in vitro data. CONCLUSION Our study reveals a dual regulatory role of GPS2 in epigenetically modulating the chromatin landscape and gene expression during human adipocyte differentiation and identifies a hitherto unknown GPS2-ABCG1 pathway potentially linked to adipocyte hypertrophy in humans.
Collapse
Affiliation(s)
- Serena Barilla
- Department of Biosciences and Nutrition, Karolinska Institute, 14183 Huddinge, Sweden.
| | - Ning Liang
- Department of Biosciences and Nutrition, Karolinska Institute, 14183 Huddinge, Sweden
| | - Enrichetta Mileti
- Department of Biosciences and Nutrition, Karolinska Institute, 14183 Huddinge, Sweden
| | - Raphaëlle Ballaire
- Centre de Recherche des Cordeliers, Inserm, University of Paris, IMMEDIAB Laboratory, F-75006, Paris, France; Inovarion, Paris, France
| | - Marie Lhomme
- ICANalytics Lipidomic, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Maharajah Ponnaiah
- ICANalytics Lipidomic, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Sophie Lemoine
- École Normale Supérieure, PSL Research University, Centre National de la Recherche Scientifique (CNRS), Inserm, Institut de Biologie de l'École Normale Supérieure (IBENS), Plateforme Génomique, Paris, France
| | - Antoine Soprani
- Centre de Recherche des Cordeliers, Inserm, University of Paris, IMMEDIAB Laboratory, F-75006, Paris, France; Department of Digestive Surgery, Générale de Santé (GDS), Geoffroy Saint Hilaire Clinic, 75005, Paris, France
| | - Jean-Francois Gautier
- Centre de Recherche des Cordeliers, Inserm, University of Paris, IMMEDIAB Laboratory, F-75006, Paris, France; Lariboisière Hospital, AP-HP, Diabetology Department, University of Paris, Paris, France
| | - Ez-Zoubir Amri
- University of Côte d'Azur, CNRS, Inserm, iBV, Nice, France
| | - Wilfried Le Goff
- Sorbonne University, Inserm, Institute of Cardiometabolism and Nutrition (ICAN), UMR_S1166, Hôpital de la Pitié, Paris, F-75013, France
| | - Nicolas Venteclef
- Centre de Recherche des Cordeliers, Inserm, University of Paris, IMMEDIAB Laboratory, F-75006, Paris, France; Lariboisière Hospital, AP-HP, Diabetology Department, University of Paris, Paris, France
| | - Eckardt Treuter
- Department of Biosciences and Nutrition, Karolinska Institute, 14183 Huddinge, Sweden.
| |
Collapse
|
15
|
Kang Z, Fan R. PPARα and NCOR/SMRT corepressor network in liver metabolic regulation. FASEB J 2020; 34:8796-8809. [DOI: 10.1096/fj.202000055rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/22/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Zhanfang Kang
- Department of Basic Medical Research Qingyuan People's HospitalThe Sixth Affiliated Hospital of Guangzhou Medical University Qingyuan China
| | - Rongrong Fan
- Department of Biosciences and Nutrition Karolinska Institute Stockholm Sweden
| |
Collapse
|
16
|
Iemolo A, Montilla-Perez P, Lai IC, Meng Y, Nolan S, Wen J, Rusu I, Dulcis D, Telese F. A cell type-specific expression map of NCoR1 and SMRT transcriptional co-repressors in the mouse brain. J Comp Neurol 2020; 528:2218-2238. [PMID: 32072640 DOI: 10.1002/cne.24886] [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: 04/10/2019] [Revised: 12/12/2019] [Accepted: 02/12/2020] [Indexed: 12/11/2022]
Abstract
The ability to rapidly change gene expression patterns is essential for differentiation, development, and functioning of the brain. Throughout development, or in response to environmental stimuli, gene expression patterns are tightly regulated by the dynamic interplay between transcription activators and repressors. Nuclear receptor corepressor 1 (NCoR1) and silencing mediator for retinoid or thyroid-hormone receptors (SMRT) are the best characterized transcriptional co-repressors from a molecular point of view. They mediate epigenetic silencing of gene expression in a wide range of developmental and homeostatic processes in many tissues, including the brain. For instance, NCoR1 and SMRT regulate neuronal stem cell proliferation and differentiation during brain development and they have been implicated in learning and memory. However, we still have a limited understanding of their regional and cell type-specific expression in the brain. In this study, we used fluorescent immunohistochemistry to map their expression patterns throughout the adult mouse brain. Our findings reveal that NCoR1 and SMRT share an overall neuroanatomical distribution, and are detected in both excitatory and inhibitory neurons. However, we observed striking differences in their cell type-specific expression in glial cells. Specifically, all oligodendrocytes express NCoR1, but only a subset express SMRT. In addition, NCoR1, but not SMRT, was detected in a subset of astrocytes and in the microglia. These novel observations are corroborated by single cell transcriptomics and emphasize how NCoR1 and SMRT may contribute to distinct biological functions, suggesting an exclusive role of NCoR1 in innate immune responses in the brain.
Collapse
Affiliation(s)
- Attilio Iemolo
- Department of Medicine, University of California San Diego, La Jolla, California
| | | | - I-Chi Lai
- Department of Psychiatry, University of California San Diego, La Jolla, California
| | - Yinuo Meng
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Syreeta Nolan
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Junneng Wen
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Iulia Rusu
- Department of Medicine, University of California San Diego, La Jolla, California
| | - Davide Dulcis
- Department of Psychiatry, University of California San Diego, La Jolla, California
| | - Francesca Telese
- Department of Medicine, University of California San Diego, La Jolla, California
| |
Collapse
|
17
|
Shimizu H, Lu Y, Vella KR, Damilano F, Astapova I, Amano I, Ritter M, Gallop MR, Rosenzweig AN, Cohen RN, Hollenberg AN. Nuclear corepressor SMRT is a strong regulator of body weight independently of its ability to regulate thyroid hormone action. PLoS One 2019; 14:e0220717. [PMID: 31404087 PMCID: PMC6690520 DOI: 10.1371/journal.pone.0220717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/22/2019] [Indexed: 12/17/2022] Open
Abstract
Silencing Mediator of Retinoid and Thyroid Hormone Receptors (SMRT) and the nuclear receptor co-repressor1 (NCoR1) are paralogs and regulate nuclear receptor (NR) function through the recruitment of a multiprotein complex that includes histone deacetylase activity. Previous genetic strategies which deleted SMRT in a specific tissue or which altered the interaction between SMRT and NRs have suggested that it may regulate adiposity and insulin sensitivity. However, the full role of SMRT in adult mice has been difficult to establish because its complete deletion during embryogenesis is lethal. To elucidate the specific roles of SMRT in mouse target tissues especially in the context of thyroid hormone (TH) signaling, we used a tamoxifen-inducible post-natal disruption strategy. We found that global SMRT deletion causes dramatic obesity even though mice were fed a standard chow diet and exhibited normal food intake. This weight gain was associated with a decrease in energy expenditure. Interestingly, the deletion of SMRT had no effect on TH action in any tissue but did regulate retinoic acid receptor (RAR) function in the liver. We also demonstrate that the deletion of SMRT leads to profound hepatic steatosis in the setting of obesity. This is unlike NCoR1 deletion, which results in hepatic steatosis due to the upregulation of lipogenic gene expression. Taken together, our data demonstrate that SMRT plays a unique and CoR specific role in the regulation of body weight and has no role in TH action. This raises the possibility that additional role of CoRs besides NCoR1 and SMRT may exist to regulate TH action.
Collapse
Affiliation(s)
- Hiroaki Shimizu
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yu Lu
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kristen R. Vella
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Endocrinology, Diabetes and Metabolism, Weill Cornell Medicine, New York, New York, United States of America
| | - Federico Damilano
- Division of Cardiology Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Inna Astapova
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Izuki Amano
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Endocrinology, Diabetes and Metabolism, Weill Cornell Medicine, New York, New York, United States of America
| | - Megan Ritter
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Endocrinology, Diabetes and Metabolism, Weill Cornell Medicine, New York, New York, United States of America
| | - Molly R. Gallop
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Anthony N. Rosenzweig
- Division of Cardiology Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Ronald N. Cohen
- Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, Illinois, United States of America
| | - Anthony N. Hollenberg
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Endocrinology, Diabetes and Metabolism, Weill Cornell Medicine, New York, New York, United States of America
| |
Collapse
|
18
|
Liang N, Jakobsson T, Fan R, Treuter E. The Nuclear Receptor-Co-repressor Complex in Control of Liver Metabolism and Disease. Front Endocrinol (Lausanne) 2019; 10:411. [PMID: 31293521 PMCID: PMC6606711 DOI: 10.3389/fendo.2019.00411] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/07/2019] [Indexed: 12/21/2022] Open
Abstract
Hepatocytes are the major cell-type in the liver responsible for the coordination of metabolism in response to multiple signaling inputs. Coordination occurs primarily at the level of gene expression via transcriptional networks composed of transcription factors, in particular nuclear receptors (NRs), and associated co-regulators, including chromatin-modifying complexes. Disturbance of these networks by genetic, environmental or nutritional factors can lead to metabolic dysregulation and has been linked to the progression of non-alcoholic fatty liver disease (NAFLD) toward steatohepatitis and even liver cancer. Since there are currently no approved therapies, major efforts are dedicated to identify the critical factors that can be employed for drug development. Amongst the identified factors with clinical significance are currently lipid-sensing NRs including PPARs, LXRs, and FXR. However, major obstacles of NR-targeting are the undesired side effects associated with the genome-wide NR activities in multiple cell-types. Thus, of particular interest are co-regulators that determine NR activities, context-selectivity, and associated chromatin states. Current research on the role of co-regulators in hepatocytes is still premature due to the large number of candidates, the limited number of available mouse models, and the technical challenges in studying their chromatin occupancy. As a result, how NR-co-regulator networks in hepatocytes are coordinated by extracellular signals, and how NR-pathway selectivity is achieved, remains currently poorly understood. We will here review a notable exception, namely a fundamental transcriptional co-repressor complex that during the past decade has become the probably most-studied and best-understood physiological relevant co-regulator in hepatocytes. This multiprotein complex contains the core subunits HDAC3, NCOR, SMRT, TBL1, TBLR1, and GPS2 and is referred to as the "NR-co-repressor complex." We will particularly discuss recent advances in characterizing hepatocyte-specific loss-of-function mouse models and in applying genome-wide sequencing approaches including ChIP-seq. Both have been instrumental to uncover the role of each of the subunits under physiological conditions and in disease models, but they also revealed insights into the NR target range and genomic mechanisms of action of the co-repressor complex. We will integrate a discussion of translational aspects about the role of the complex in NAFLD pathways and in particular about the hypothesis that patient-specific alterations of specific subunits may determine NAFLD susceptibility and the therapeutic outcomes of NR-directed treatments.
Collapse
Affiliation(s)
- Ning Liang
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Tomas Jakobsson
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Rongrong Fan
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Eckardt Treuter
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
- *Correspondence: Eckardt Treuter
| |
Collapse
|
19
|
Corepressor SMRT is required to maintain Hox transcriptional memory during somitogenesis. Proc Natl Acad Sci U S A 2018; 115:10381-10386. [PMID: 30254164 PMCID: PMC6187131 DOI: 10.1073/pnas.1809480115] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Retinoic acid (RA) is an important transcriptional regulator during both vertebrate and invertebrate body pattern formation. The Homeobox (Hox) gene family is activated by a gradient of RA formed along the length of the embryo at specific time points during fetal development. Generation of a genetically modified mouse harboring mutations in the SMRT repressor demonstrated that SMRT-dependent repression of retinoic acid receptor (RAR) is critical to establish and maintain the somitic Hox code and segmental identity during fetal development via epigenetic marking of target loci. Nuclear hormone receptors (NRs), such as retinoic acid receptors (RARs), play critical roles in vertebrate development and homeostasis by regulating target gene transcription. Their activity is controlled by ligand-dependent release of corepressors and subsequent recruitment of coactivators, but how these individual receptor modes contribute to development are unknown. Here, we show that mice carrying targeted knockin mutations in the corepressor Silencing Mediator of Retinoid and Thyroid hormone receptor (SMRT) that specifically disable SMRT function in NR signaling (SMRTmRID), display defects in cranial neural crest cell-derived structures and posterior homeotic transformations of axial vertebrae. SMRTmRID embryos show enhanced transcription of RAR targets including Hox loci, resulting in respecification of vertebral identities. Up-regulated histone acetylation and decreased H3K27 methylation are evident in the Hox loci whose somitic expression boundaries are rostrally shifted. Furthermore, enhanced recruitment of super elongation complex is evident in rapidly induced non-Pol II-paused targets in SMRTmRID embryonic stem cells. These results demonstrate that SMRT-dependent repression of RAR is critical to establish and maintain the somitic Hox code and segmental identity during fetal development via epigenetic marking of target loci.
Collapse
|
20
|
Zhang F, Lu S, He J, Jin H, Wang F, Wu L, Shao J, Chen A, Zheng S. Ligand Activation of PPARγ by Ligustrazine Suppresses Pericyte Functions of Hepatic Stellate Cells via SMRT-Mediated Transrepression of HIF-1α. Am J Cancer Res 2018; 8:610-626. [PMID: 29344293 PMCID: PMC5771080 DOI: 10.7150/thno.22237] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 10/22/2017] [Indexed: 12/31/2022] Open
Abstract
Rationale: Hepatic stellate cells (HSCs) are liver-specific pericytes regulating vascular remodeling during hepatic fibrosis. Here, we investigated how ligustrazine affects HSC pericyte functions. Methods: Rat HSC-T6 and human HSC-LX2 cells were cultured, and multiple molecular experiments including real-time PCR, Western blot, flow cytometry, immunofluorescence, electrophoretic mobility shift assay and co-immunoprecipitation were used to elucidate the underlying mechanisms. Molecular simulation and site-directed mutagenesis were performed to uncover the target molecule of ligustrazine. Rats were intoxicated with CCl4 for evaluating ligustrazine's effects in vivo. Results: Ligustrazine inhibited angiogenic cytokine production, migration, adhesion and contraction in HSCs, and activated PPARγ. Selective PPARγ inhibitor GW9662 potently abrogated ligustrazine suppression of HSC pericyte functions. Additionally, HIF-1α inhibitor PX-478 repressed HSC pericyte functions, and ligustrazine inhibited the transcription of HIF-1α, which was diminished by GW9662. Moreover, ligustrazine downregulation of HIF-1α was rescued by knockdown of SMRT, and ligustrazine increased PPARγ physical interaction with SMRT, which was abolished by GW9662. These findings collectively indicated that activation of PPARγ by ligustrazine led to transrepression of HIF-1α via a SMRT-dependent mechanism. Furthermore, molecular docking evidence revealed that ligustrazine bound to PPARγ in a unique double-molecule manner via hydrogen bonding with the residues Ser289 and Ser342. Site-directed mutation of Ser289 and/or Ser342 resulted in the loss of ligustrazine transrepression of HIF-1α in HSCs, indicating that interactions with both the residues were indispensable for ligustrazine effects. Finally, ligustrazine improved hepatic injury, angiogenesis and vascular remodeling in CCl4-induced liver fibrosis in rats. Conclusions: We discovered a novel ligand activation pattern for PPARγ transrepression of the target gene with therapeutic implications in HSC pericyte biology and liver fibrosis.
Collapse
|
21
|
Vella KR, Hollenberg AN. The actions of thyroid hormone signaling in the nucleus. Mol Cell Endocrinol 2017; 458:127-135. [PMID: 28286327 PMCID: PMC5592130 DOI: 10.1016/j.mce.2017.03.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/27/2017] [Accepted: 03/02/2017] [Indexed: 12/15/2022]
Abstract
Thyroid hormones are a critical regulator of mammalian physiology. Much of their action is due to effects in the nucleus where T3 engages thyroid hormone receptor isoforms to mediate its effects. In order to function properly the TR isoforms must be recruited to regulatory sequences within genes that they up-regulate. On these positive regulated target genes the TR can activate or repress depending upon whether the receptor is bound to T3 or not and the type of co-regulatory proteins present in that cell type. In contrast to T3 mediated activation, the mechanism by which the TR represses transcription in the presence of T3 remains unclear. Herein we will review the components of the transcriptional response to T3 within the nucleus and attempt to highlight the outstanding questions in the field.
Collapse
Affiliation(s)
- Kristen R Vella
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Anthony N Hollenberg
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States.
| |
Collapse
|
22
|
Short S, Peterkin T, Guille M, Patient R, Sharpe C. Short linear motif acquisition, exon formation and alternative splicing determine a pathway to diversity for NCoR-family co-repressors. Open Biol 2016; 5:rsob.150063. [PMID: 26289800 PMCID: PMC4554918 DOI: 10.1098/rsob.150063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Vertebrate NCoR-family co-repressors play central roles in the timing of embryo and stem cell differentiation by repressing the activity of a range of transcription factors. They interact with nuclear receptors using short linear motifs (SLiMs) termed co-repressor for nuclear receptor (CoRNR) boxes. Here, we identify the pathway leading to increasing co-repressor diversity across the deuterostomes. The final complement of CoRNR boxes arose in an ancestral cephalochordate, and was encoded in one large exon; the urochordates and vertebrates then split this region between 10 and 12 exons. In Xenopus, alternative splicing is prevalent in NCoR2, but absent in NCoR1. We show for one NCoR1 exon that alternative splicing can be recovered by a single point mutation, suggesting NCoR1 lost the capacity for alternative splicing. Analyses in Xenopus and zebrafish identify that cellular context, rather than gene sequence, predominantly determines species differences in alternative splicing. We identify a pathway to diversity for the NCoR family beginning with the addition of a SLiM, followed by gene duplication, the generation of alternatively spliced isoforms and their differential deployment.
Collapse
Affiliation(s)
- Stephen Short
- Institute of Marine Sciences, School of Biological Science, University of Portsmouth, Portsmouth PO1 2DY, UK
| | - Tessa Peterkin
- The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Matthew Guille
- Institute of Biomolecular and Biomedical Science, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK European Xenopus Resource Centre, University of Portsmouth, St Michael's Building, Portsmouth PO1 2DT, UK
| | - Roger Patient
- The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Colin Sharpe
- Institute of Biomolecular and Biomedical Science, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK European Xenopus Resource Centre, University of Portsmouth, St Michael's Building, Portsmouth PO1 2DT, UK
| |
Collapse
|
23
|
Astapova I. Role of co-regulators in metabolic and transcriptional actions of thyroid hormone. J Mol Endocrinol 2016; 56:73-97. [PMID: 26673411 DOI: 10.1530/jme-15-0246] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/16/2015] [Indexed: 12/18/2022]
Abstract
Thyroid hormone (TH) controls a wide range of physiological processes through TH receptor (TR) isoforms. Classically, TRs are proposed to function as tri-iodothyronine (T3)-dependent transcription factors: on positively regulated target genes, unliganded TRs mediate transcriptional repression through recruitment of co-repressor complexes, while T3 binding leads to dismissal of co-repressors and recruitment of co-activators to activate transcription. Co-repressors and co-activators were proposed to play opposite roles in the regulation of negative T3 target genes and hypothalamic-pituitary-thyroid axis, but exact mechanisms of the negative regulation by TH have remained elusive. Important insights into the roles of co-repressors and co-activators in different physiological processes have been obtained using animal models with disrupted co-regulator function. At the same time, recent studies interrogating genome-wide TR binding have generated compelling new data regarding effects of T3, local chromatin structure, and specific response element configuration on TR recruitment and function leading to the proposal of new models of transcriptional regulation by TRs. This review discusses data obtained in various mouse models with manipulated function of nuclear receptor co-repressor (NCoR or NCOR1) and silencing mediator of retinoic acid receptor and thyroid hormone receptor (SMRT or NCOR2), and family of steroid receptor co-activators (SRCs also known as NCOAs) in the context of TH action, as well as insights into the function of co-regulators that may emerge from the genome-wide TR recruitment analysis.
Collapse
Affiliation(s)
- Inna Astapova
- Division of Endocrinology, Diabetes and MetabolismBeth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
24
|
Shibata S. Context-dependent mechanisms modulating aldosterone signaling in the kidney. Clin Exp Nephrol 2016; 20:663-670. [PMID: 26846783 DOI: 10.1007/s10157-016-1232-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/08/2016] [Indexed: 12/16/2022]
Abstract
The aldosterone-mineralocorticoid receptor (MR) system serves as the major regulator of fluid homeostasis, and is an important drug target for the treatment of hypertension, heart failure, and chronic kidney disease. While the ligand aldosterone plays a central role in facilitating MR activity, recent studies have revealed that MR signaling is modulated through distinct mechanisms at the levels of the receptor and the downstream targets. Notably, phosphorylation of the ligand-binding domain in MR regulates the ability of the receptor to bind to ligand in renal intercalated cells, providing an additional layer of regulation that allows the cell-selective control of MR signaling. These mechanisms are involved in the context-dependent effects of aldosterone in the distal nephron. In this article, the recent progress in the understanding of mechanisms regulating the action of aldosterone is discussed, focusing on the connecting tubules and collecting duct in the kidney.
Collapse
Affiliation(s)
- Shigeru Shibata
- Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan. .,Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
| |
Collapse
|
25
|
Youssef J, Badr M. Peroxisome Proliferator-Activated Receptors Features, Functions, and Future. NUCLEAR RECEPTOR RESEARCH 2015. [DOI: 10.11131/2015/101188] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
|
26
|
Snyder CA, Goodson ML, Schroeder AC, Privalsky ML. Regulation of corepressor alternative mRNA splicing by hormonal and metabolic signaling. Mol Cell Endocrinol 2015; 413:228-35. [PMID: 26166430 PMCID: PMC4556269 DOI: 10.1016/j.mce.2015.06.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/24/2015] [Accepted: 06/29/2015] [Indexed: 12/14/2022]
Abstract
Alternative mRNA splicing diversifies the products encoded by the NCoR and SMRT corepressor loci. There is a programmed alteration in NCoR mRNA splicing during adipocyte differentiation from an NCoRω isoform, which contains three nuclear receptor interaction domains, to an NCoRδ isoform that contains two nuclear receptor interaction domains. This alternative mRNA splicing of NCoR has profound effects on adiposity and on diabetes in mouse models. We report here that dexamethasone, a powerful regulator of metabolism and of adipocyte differentiation, confers this change in NCoR mRNA splicing in cultured adipocytes. We also demonstrate that changes in dietary components can consistently, if moderately, modulate the total transcript levels and the mRNA splicing of NCoR and SMRT in both cultured cells and intact mice. This ability of alternative corepressor mRNA splicing to respond to nutritional changes confirms its importance in regulating glucose and lipid metabolism, and its promise as a therapeutic candidate for metabolic disorders such as type 2 diabetes.
Collapse
Affiliation(s)
- Chelsea A Snyder
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, USA.
| | - Michael L Goodson
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, USA.
| | - Amy C Schroeder
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, USA.
| | - Martin L Privalsky
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, USA.
| |
Collapse
|
27
|
Imaging Fibrosis and Separating Collagens using Second Harmonic Generation and Phasor Approach to Fluorescence Lifetime Imaging. Sci Rep 2015; 5:13378. [PMID: 26293987 PMCID: PMC4543938 DOI: 10.1038/srep13378] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/24/2015] [Indexed: 01/13/2023] Open
Abstract
In this paper we have used second harmonic generation (SHG) and phasor approach to auto fluorescence lifetime imaging (FLIM) to obtain fingerprints of different collagens and then used these fingerprints to observe bone marrow fibrosis in the mouse femur. This is a label free approach towards fast automatable detection of fibrosis in tissue samples. FLIM has previously been used as a method of contrast in different tissues and in this paper phasor approach to FLIM is used to separate collagen I from collagen III, the markers of fibrosis, the largest groups of disorders that are often without any effective therapy. Often characterized by an increase in collagen content of the corresponding tissue, the samples are usually visualized by histochemical staining, which is pathologist dependent and cannot be automated.
Collapse
|
28
|
Martin KA, Mani MV, Mani A. New targets to treat obesity and the metabolic syndrome. Eur J Pharmacol 2015; 763:64-74. [PMID: 26001373 DOI: 10.1016/j.ejphar.2015.03.093] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 03/19/2015] [Accepted: 03/30/2015] [Indexed: 01/12/2023]
Abstract
Metabolic syndrome (MetS) is a cluster ofassociated metabolic traits that collectively confer unsurpassed risk for development of cardiovascular disease (CVD) and type 2 diabetes compared to any single CVD risk factor. Truncal obesity plays an exceptionally critical role among all metabolic traits of the MetS. Consequently, the prevalence of the MetS has steadily increased with the growing epidemic of obesity. Pharmacotherapy has been available for obesity for more than one decade, but with little success in improving the metabolic profiles. The serotonergic drugs and inhibitors of pancreatic lipases were among the few drugs that were initially approved to treat obesity. At the present time, only the pancreatic lipase inhibitor orlistat is approved for long-term treatment of obesity. New classes of anti-diabetic drugs, including glucagon-like peptide 1 receptor (GLP-1R) agonists and Dipeptidyl-peptidase IV (DPP-IV) inhibitors, are currently being evaluated for their effects on obesity and metabolic traits. The genetic studies of obesity and metabolic syndrome have identified novel molecules acting on the hunger and satiety peptidergic signaling of the gut-hypothalamus axis or the melanocortin system of the brain and are promising targets for future drug development. The goal is to develop drugs that not only treat obesity, but also favorably impact its associated traits.
Collapse
Affiliation(s)
- Kathleen A Martin
- Department of Internal Medicine, Yale University School of Medicine, USA
| | | | - Arya Mani
- Department of Internal Medicine, Yale University School of Medicine, USA; Department of Genetics, Yale University School of Medicine, USA.
| |
Collapse
|
29
|
Emont MP, Mantis S, Kahn JH, Landeche M, Han X, Sargis RM, Cohen RN. Silencing Mediator of Retinoid and Thyroid Hormone Receptors (SMRT) regulates glucocorticoid action in adipocytes. Mol Cell Endocrinol 2015; 407:52-6. [PMID: 25766503 PMCID: PMC4390535 DOI: 10.1016/j.mce.2015.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 02/28/2015] [Accepted: 03/02/2015] [Indexed: 11/15/2022]
Abstract
Local modulation of glucocorticoid action in adipocytes regulates adiposity and systemic insulin sensitivity. However, the specific cofactors that mediate glucocorticoid receptor (GR) action in adipocytes remain unclear. Here we show that the silencing mediator of retinoid and thyroid hormone receptors (SMRT) is recruited to GR in adipocytes and regulates ligand-dependent GR function. Decreased SMRT expression in adipocytes in vivo increases expression of glucocorticoid-responsive genes. Moreover, adipocytes with decreased SMRT expression exhibit altered glucocorticoid regulation of lipolysis. We conclude that SMRT regulates the metabolic functions of GR in adipocytes in vivo. Modulation of GR-SMRT interactions in adipocytes represents a novel approach to control the local degree of glucocorticoid action and thus influence adipocyte metabolic function.
Collapse
Affiliation(s)
- Margo P Emont
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA
| | - Stelios Mantis
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA
| | - Jonathan H Kahn
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA
| | - Michael Landeche
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA
| | - Xuan Han
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA
| | - Robert M Sargis
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA
| | - Ronald N Cohen
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Chicago, 900 E 57th Street, KCBD 8126, Chicago, IL 60637, USA.
| |
Collapse
|
30
|
Guo C, Li Y, Gow CH, Wong M, Zha J, Yan C, Liu H, Wang Y, Burris TP, Zhang J. The optimal corepressor function of nuclear receptor corepressor (NCoR) for peroxisome proliferator-activated receptor γ requires G protein pathway suppressor 2. J Biol Chem 2014; 290:3666-79. [PMID: 25519902 DOI: 10.1074/jbc.m114.598797] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Repression of peroxisome proliferator-activated receptor γ (PPARγ)-dependent transcription by the nuclear receptor corepressor (NCoR) is important for homeostatic expression of PPARγ target genes in vivo. The current model states that NCoR-mediated repression requires its direct interaction with PPARγ in the repressive conformation. Previous studies, however, have shown that DNA-bound PPARγ is incompatible with a direct, high-affinity association with NCoR because of the inherent ability of PPARγ to adopt the active conformation. Here we show that NCoR acquires the ability to repress active PPARγ-mediated transcription via G protein pathway suppressor 2 (GPS2), a component of the NCoR corepressor complex. Unlike NCoR, GPS2 can recognize and bind the active state of PPARγ. In GPS2-deficient mouse embryonic fibroblast cells, loss of GPS2 markedly reduces the corepressor function of NCoR for PPARγ, leading to constitutive activation of PPARγ target genes and spontaneous adipogenesis of the cells. GPS2, however, is dispensable for repression mediated by unliganded thyroid hormone receptor α or a PPARγ mutant unable to adopt the active conformation. This study shows that GPS2, although dispensable for the intrinsic repression function of NCoR, can mediate a novel corepressor repression pathway that allows NCoR to directly repress active PPARγ-mediated transcription, which is important for the optimal corepressor function of NCoR for PPARγ. Interestingly, GPS2-dependent repression specifically targets PPARγ but not PPARα or PPARδ. Therefore, GPS2 may serve as a unique target to manipulate PPARγ signaling in diseases.
Collapse
Affiliation(s)
- Chun Guo
- From the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Yali Li
- the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Chien-Hung Gow
- the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, the Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan
| | - Madeline Wong
- From the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104
| | - Jikun Zha
- From the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104
| | - Chunxia Yan
- the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, the College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710049, China, and
| | - Hongqi Liu
- the Infection and Immunity Research Group, Institute of Medical Biology, Chinese Academy of Medical Science, Peking Union Medical College, Kunming, Yunnan 650018, China
| | - Yongjun Wang
- From the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104
| | - Thomas P Burris
- From the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104
| | - Jinsong Zhang
- From the Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267,
| |
Collapse
|
31
|
Abstract
NCoR1 (nuclear receptor corepressor) and SMRT (silencing mediator of retinoid and thyroid hormone receptors; NCoR2) are well-recognized coregulators of nuclear receptor (NR) action. However, their unique roles in the regulation of thyroid hormone (TH) signaling in specific cell types have not been determined. To accomplish this we generated mice that lacked function of either NCoR1, SMRT, or both in the liver only and additionally a global SMRT knockout model. Despite both corepressors being present in the liver, deletion of SMRT in either euthyroid or hypothyroid animals had little effect on TH signaling. In contrast, disruption of NCoR1 action confirmed that NCoR1 is the principal mediator of TH sensitivity in vivo. Similarly, global disruption of SMRT, unlike the global disruption of NCoR1, did not affect TH levels. While SMRT played little role in TH-regulated pathways, when disrupted in combination with NCoR1, it greatly accentuated the synthesis and storage of hepatic lipid. Taken together, these data demonstrate that corepressor specificity exists in vivo and that NCoR1 is the principal regulator of TH action. However, both corepressors collaborate to control hepatic lipid content, which likely reflects their cooperative activity in regulating the action of multiple NRs including the TH receptor (TR).
Collapse
|
32
|
Abstract
In recent years white adipose tissue inflammation has been recognized to be associated with obesity. Adipocytes and adipose tissue associated macrophages (ATMs) secrete bioactive molecules, including adipokines, chemokines/cytokines and free fatty acids that modulate the development of low-grade inflammation and insulin resistance responsible for obesity-related metabolic and cardiovascular diseases. Nuclear receptors, notably peroxisome-proliferator-activated receptors, are sensors of dietary lipids and control transcriptional programs of key metabolic and inflammatory pathways in adipocytes and macrophages. This review focuses on mechanisms by which nuclear receptors maintain white adipose tissue homeostasis. The identification of ATMs as active players in the initiation of chronic inflammation and the links between inflammatory signaling and metabolic dysfunction will be presented, followed by discussion of recent evidence for nuclear receptors in ATM function, with an emphasis on the paracrine interaction between adipocytes and ATMs.
Collapse
|
33
|
Transcriptional coregulators: fine-tuning metabolism. Cell Metab 2014; 20:26-40. [PMID: 24794975 PMCID: PMC4079747 DOI: 10.1016/j.cmet.2014.03.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 12/21/2022]
Abstract
Metabolic homeostasis requires that cellular energy levels are adapted to environmental cues. This adaptation is largely regulated at the transcriptional level, through the interaction between transcription factors, coregulators, and the basal transcriptional machinery. Coregulators, which function as both metabolic sensors and transcriptional effectors, are ideally positioned to synchronize metabolic pathways to environmental stimuli. The balance between inhibitory actions of corepressors and stimulatory effects of coactivators enables the fine-tuning of metabolic processes. This tight regulation opens therapeutic opportunities to manage metabolic dysfunction by directing the activity of cofactors toward specific transcription factors, pathways, or cells/tissues, thereby restoring whole-body metabolic homeostasis.
Collapse
|
34
|
Gao H, Mejhert N, Fretz JA, Arner E, Lorente-Cebrián S, Ehrlund A, Dahlman-Wright K, Gong X, Strömblad S, Douagi I, Laurencikiene J, Dahlman I, Daub CO, Rydén M, Horowitz MC, Arner P. Early B cell factor 1 regulates adipocyte morphology and lipolysis in white adipose tissue. Cell Metab 2014; 19:981-92. [PMID: 24856929 PMCID: PMC4109056 DOI: 10.1016/j.cmet.2014.03.032] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 02/11/2014] [Accepted: 03/26/2014] [Indexed: 01/09/2023]
Abstract
White adipose tissue (WAT) morphology characterized by hypertrophy (i.e., fewer but larger adipocytes) associates with increased adipose inflammation, lipolysis, insulin resistance, and risk of diabetes. However, the causal relationships and the mechanisms controlling WAT morphology are unclear. Herein, we identified EBF1 as an adipocyte-expressed transcription factor with decreased expression/activity in WAT hypertrophy. In human adipocytes, the regulatory targets of EBF1 were enriched for genes controlling lipolysis and adipocyte morphology/differentiation, and in both humans and murine models, reduced EBF1 levels associated with increased lipolysis and adipose hypertrophy. Although EBF1 did not affect adipose inflammation, TNFα reduced EBF1 gene expression. High-fat diet intervention in Ebf1(+/-) mice resulted in more pronounced WAT hypertrophy and attenuated insulin sensitivity compared with wild-type littermate controls. We conclude that EBF1 is an important regulator of adipose morphology and fat cell lipolysis and may constitute a link between WAT inflammation, altered lipid metabolism, adipose hypertrophy, and insulin resistance.
Collapse
Affiliation(s)
- Hui Gao
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Niklas Mejhert
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Jackie A Fretz
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT 06520, USA
| | - Erik Arner
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden; RIKEN Center for Life Science Technologies (Division of Genomic Technologies), RIKEN Yokohama Institute, Yokohama, Kanagawa, 230-0045, Japan
| | | | - Anna Ehrlund
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Karin Dahlman-Wright
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, SE-141 86, Sweden; Science for Life Laboratory, Solna, SE-171 21, Sweden
| | - Xiaowei Gong
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Staffan Strömblad
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Iyadh Douagi
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Jurga Laurencikiene
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Ingrid Dahlman
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Carsten O Daub
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, SE-141 86, Sweden; RIKEN Center for Life Science Technologies (Division of Genomic Technologies), RIKEN Yokohama Institute, Yokohama, Kanagawa, 230-0045, Japan
| | - Mikael Rydén
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden
| | - Mark C Horowitz
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT 06520, USA.
| | - Peter Arner
- Department of Medicine (H7), Karolinska Institutet, Stockholm, SE-141 86, Sweden.
| |
Collapse
|
35
|
Gao Y, Hamers N, Rakhshandehroo M, Berger R, Lough J, Kalkhoven E. Allele compensation in tip60+/- mice rescues white adipose tissue function in vivo. PLoS One 2014; 9:e98343. [PMID: 24870614 PMCID: PMC4037199 DOI: 10.1371/journal.pone.0098343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 05/01/2014] [Indexed: 01/14/2023] Open
Abstract
Adipose tissue is a key regulator of energy homestasis. The amount of adipose tissue is largely determined by adipocyte differentiation (adipogenesis), a process that is regulated by the concerted actions of multiple transcription factors and cofactors. Based on in vitro studies in murine 3T3-L1 preadipocytes and human primary preadipocytes, the transcriptional cofactor and acetyltransferase Tip60 was recently identified as an essential adipogenic factor. We therefore investigated the role of Tip60 on adipocyte differentiation and function, and possible consequences on energy homeostasis, in vivo. Because homozygous inactivation results in early embryonic lethality, Tip60+/− mice were used. Heterozygous inactivation of Tip60 had no effect on body weight, despite slightly higher food intake by Tip60+/− mice. No major effects of heterozygous inactivation of Tip60 were observed on adipose tissue and liver, and Tip60+/− displayed normal glucose tolerance, both on a low fat and a high fat diet. While Tip60 mRNA was reduced to 50% in adipose tissue, the protein levels were unaltered, suggesting compensation by the intact allele. These findings indicate that the in vivo role of Tip60 in adipocyte differentiation and function cannot be properly addressed in Tip60+/− mice, but requires the generation of adipose tissue-specific knock out animals or specific knock-in mice.
Collapse
Affiliation(s)
- Yuan Gao
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Center, Leiden, The Netherlands
| | - Nicole Hamers
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Center, Leiden, The Netherlands
| | - Maryam Rakhshandehroo
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Ruud Berger
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Center, Leiden, The Netherlands
| | - John Lough
- Department of Cell Biology, Neurobiology and Anatomy and the Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Eric Kalkhoven
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands
- Netherlands Metabolomics Center, Leiden, The Netherlands
- * E-mail:
| |
Collapse
|
36
|
Picou F, Fauquier T, Chatonnet F, Richard S, Flamant F. Deciphering direct and indirect influence of thyroid hormone with mouse genetics. Mol Endocrinol 2014; 28:429-41. [PMID: 24617548 DOI: 10.1210/me.2013-1414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
T3, the active form of thyroid hormone, binds nuclear receptors that regulate the transcription of a large number of genes in many cell types. Unraveling the direct and indirect effect of this hormonal stimulation, and establishing links between these molecular events and the developmental and physiological functions of the hormone, is a major challenge. New mouse genetics tools, notably those based on Cre/loxP technology, are suitable to perform a multiscale analysis of T3 signaling and achieve this task.
Collapse
Affiliation(s)
- Frédéric Picou
- Université de Lyon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Claude Bernard Lyon 1, École Normale, Supérieure de Lyon, Institut de Génomique Fonctionnelle de Lyon, Lyon, France
| | | | | | | | | |
Collapse
|
37
|
Sun Z, Feng D, Fang B, Mullican SE, You SH, Lim HW, Everett LJ, Nabel CS, Li Y, Selvakumaran V, Won KJ, Lazar MA. Deacetylase-independent function of HDAC3 in transcription and metabolism requires nuclear receptor corepressor. Mol Cell 2013; 52:769-82. [PMID: 24268577 DOI: 10.1016/j.molcel.2013.10.022] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/17/2013] [Accepted: 10/14/2013] [Indexed: 11/30/2022]
Abstract
Histone deacetylases (HDACs) are believed to regulate gene transcription by catalyzing deacetylation reactions. HDAC3 depletion in mouse liver upregulates lipogenic genes and results in severe hepatosteatosis. Here we show that pharmacologic HDAC inhibition in primary hepatocytes causes histone hyperacetylation but does not upregulate expression of HDAC3 target genes. Meanwhile, deacetylase-dead HDAC3 mutants can rescue hepatosteatosis and repress lipogenic genes expression in HDAC3-depleted mouse liver, demonstrating that histone acetylation is insufficient to activate gene transcription. Mutations abolishing interactions with the nuclear receptor corepressor (NCOR or SMRT) render HDAC3 nonfunctional in vivo. Additionally, liver-specific knockout of NCOR, but not SMRT, causes metabolic and transcriptomal alterations resembling those of mice without hepatic HDAC3, demonstrating that interaction with NCOR is essential for deacetylase-independent function of HDAC3. These findings highlight nonenzymatic roles of a major HDAC in transcriptional regulation in vivo and warrant reconsideration of the mechanism of action of HDAC inhibitors.
Collapse
Affiliation(s)
- Zheng Sun
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dan Feng
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bin Fang
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shannon E Mullican
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Seo-Hee You
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hee-Woong Lim
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Logan J Everett
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christopher S Nabel
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yun Li
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vignesh Selvakumaran
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
38
|
Rescue of a primary myelofibrosis model by retinoid-antagonist therapy. Proc Natl Acad Sci U S A 2013; 110:18820-5. [PMID: 24191050 DOI: 10.1073/pnas.1318974110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Molecular targeting of the two receptor interaction domains of the epigenetic repressor silencing mediator of retinoid and thyroid hormone receptors (SMRT(mRID)) produced a transplantable skeletal syndrome that reduced radial bone growth, increased numbers of bone-resorbing periosteal osteoclasts, and increased bone fracture risk. Furthermore, SMRT(mRID) mice develop spontaneous primary myelofibrosis, a chronic, usually idiopathic disorder characterized by progressive bone marrow fibrosis. Frequently linked to polycythemia vera and chronic myeloid leukemia, myelofibrosis displays high patient morbidity and mortality, and current treatment is mostly palliative. To decipher the etiology of this disease, we identified the thrombopoietin (Tpo) gene as a target of the SMRT-retinoic acid receptor signaling pathway in bone marrow stromal cells. Chronic induction of Tpo in SMRT(mRID) mice results in up-regulation of TGF-β and PDGF in megakaryocytes, uncontrolled proliferation of bone marrow reticular cells, and fibrosis of the marrow compartment. Of therapeutic relevance, we show that this syndrome can be rescued by retinoid antagonists, demonstrating that the physical interface between SMRT and retinoic acid receptor can be a potential therapeutic target to block primary myelofibrosis disease progression.
Collapse
|
39
|
Liu S, Reilly SM, Lee CH. Transcriptional repression of mitochondrial function in aging: a novel role for the silencing mediator of retinoid and thyroid hormone receptors co-repressor. Antioxid Redox Signal 2013; 19:299-309. [PMID: 22703297 PMCID: PMC3691917 DOI: 10.1089/ars.2011.4413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE Mitochondrial function plays an important role in metabolic homeostasis and has been implicated in aging. Although there is still ongoing debate regarding whether mitochondrion-derived oxidative stress is causative to the aging process, interventions that increase oxidative metabolism and antioxidant pathways in animal models protect against age-related deterioration, such as metabolic diseases and neurodegenerative disorders. RECENT ADVANCES One of the well-characterized transcriptional networks known to improve mitochondrial activity is mediated by transcriptional co-activator peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α), which is activated by AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), two of the major energy sensing molecules that are responsible for the longevity effect of caloric restriction in certain model systems. PGC-1α co-activates several nuclear receptors, notably members of the peroxisome proliferator-activated receptor (PPAR) family, which are key regulators of mitochondrial oxidative metabolism. CRITICAL ISSUES Although the AMPK/SIRT1-PGC-1α-PPAR axis plays a prominent role in activating mitochondrial functions, their activities are down-regulated in older animals, suggesting the involvement of dominant negative regulatory mechanisms in the process of aging. FUTURE DIRECTIONS In this review, we will discuss the role of a transcriptional co-repressor, silencing mediator of retinoid and thyroid hormone receptors (SMRT), whose activity and expression are increased with age, as a negative regulator of mitochondrial function that promotes aging and age-related metabolic diseases.
Collapse
Affiliation(s)
- Sihao Liu
- Division of Biological Sciences, Department of Genetics and Complex Diseases, Harvard University School of Public Health, Boston, Massachusetts, USA
| | | | | |
Collapse
|
40
|
Mottis A, Mouchiroud L, Auwerx J. Emerging roles of the corepressors NCoR1 and SMRT in homeostasis. Genes Dev 2013; 27:819-35. [PMID: 23630073 DOI: 10.1101/gad.214023.113] [Citation(s) in RCA: 207] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Epigenetic regulation of gene expression is strongly influenced by the accessibility of nucleosomal DNA or the state of chromatin compaction. In this context, coregulators, including both coactivators and corepressors, are pivotal intermediates that bridge chromatin-modifying enzymes and transcription factors. NCoR1 (nuclear receptor corepressor) and SMRT (silencing mediator of retinoic acid and thyroid hormone receptor) are among the best-characterized corepressors from a molecular point of view. These coregulators have conserved orthologs in lower organisms, which underscores their functional importance. Here we summarize the results from recent in vivo studies that reveal the wide-ranging roles of NCoR1 and SMRT in developmental as well as homeostatic processes, including metabolism, inflammation, and circadian rhythms. We also discuss the potential implications of NCoR1 and SMRT regulation of pathways ranging from genomic stability and carcinogenesis to metabolic diseases such as type 2 diabetes.
Collapse
Affiliation(s)
- Adrienne Mottis
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | | | | |
Collapse
|
41
|
You SH, Lim HW, Sun Z, Broache M, Won KJ, Lazar MA. Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo. Nat Struct Mol Biol 2013; 20:182-7. [PMID: 23292142 PMCID: PMC3565028 DOI: 10.1038/nsmb.2476] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/26/2012] [Indexed: 12/11/2022]
Abstract
Histone deacetylase 3 (HDAC3) is an epigenome-modifying enzyme that is required for normal mouse development and tissue-specific functions. In vitro, HDAC3 protein itself has minimal enzyme activity but gains its histone-deacetylation function from stable association with the conserved deacetylase-activating domain (DAD) contained in nuclear receptor co-repressors NCOR1 and SMRT. Here we show that HDAC3 enzyme activity is undetectable in mice bearing point mutations in the DAD of both NCOR1 and SMRT (NS-DADm), despite having normal levels of HDAC3 protein. Local histone acetylation is increased, and genomic HDAC3 recruitment is reduced though not abrogated. Notably, NS-DADm mice are born and live to adulthood, whereas genetic deletion of HDAC3 is embryonic lethal. These findings demonstrate that nuclear receptor co-repressors are required for HDAC3 enzyme activity in vivo and suggest that a deacetylase-independent function of HDAC3 may be required for life.
Collapse
Affiliation(s)
- Seo-Hee You
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hee-Woong Lim
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zheng Sun
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Molly Broache
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A. Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
42
|
Zhao J, Pei G. Arrestins in metabolic regulation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 118:413-27. [PMID: 23764063 DOI: 10.1016/b978-0-12-394440-5.00016-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review summarizes the regulatory roles of β-arrestins in whole-body energy balance, body weight control, and carbohydrate and lipid homeostasis. Much research has pointed in the direction of the functions of β-arrestins in mediating desensitization and endocytosis of G protein-coupled receptors as well as in activating the receptor/β-arrestin/ERK signaling pathway being crucial for metabolic regulation. Furthermore, β-arrestins form diverse signal complexes for the activation of the downstream cassettes for the body's metabolic reactions. However, further studies are required to fully address the emerging roles of β-arrestins in metabolic regulation and related diseases.
Collapse
Affiliation(s)
- Jian Zhao
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, PR China
| | | |
Collapse
|
43
|
Toubal A, Clément K, Fan R, Ancel P, Pelloux V, Rouault C, Veyrie N, Hartemann A, Treuter E, Venteclef N. SMRT-GPS2 corepressor pathway dysregulation coincides with obesity-linked adipocyte inflammation. J Clin Invest 2012; 123:362-79. [PMID: 23221346 DOI: 10.1172/jci64052] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 10/04/2012] [Indexed: 12/17/2022] Open
Abstract
Low-grade chronic inflammation is a major characteristic of obesity and results from deregulated white adipose tissue function. Consequently, there is interest in identifying the underlying regulatory mechanisms and components that drive adipocyte inflammation. Here, we report that expression of the transcriptional corepressor complex subunits GPS2 and SMRT was significantly reduced in obese adipose tissue, inversely correlated to inflammatory status, and was restored upon gastric bypass surgery-induced weight loss in morbid obesity. These alterations correlated with reduced occupancy of the corepressor complex at inflammatory promoters, providing a mechanistic explanation for elevated inflammatory transcription. In support of these correlations, RNAi-mediated depletion of GPS2 and SMRT from cultured human adipocytes promoted derepression of inflammatory transcription and elevation of obesity-associated inflammatory markers, such as IL-6 and MCP-1. Furthermore, we identified a regulatory cascade containing PPARγ and TWIST1 that controlled the expression of GPS2 and SMRT in human adipocytes. These findings were clinically relevant, because treatment of diabetic obese patients with pioglitazone, an antidiabetic and antiinflammatory PPARγ agonist, restored expression of TWIST1, GPS2, and SMRT in adipose tissue. Collectively, our findings identify alterations in a regulatory transcriptional network in adipocytes involving the dysregulation of a specific corepressor complex as among the initiating events promoting adipose tissue inflammation in human obesity.
Collapse
Affiliation(s)
- Amine Toubal
- Institute of Cardiometabolism and Nutrition, Paris, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Transcriptional Regulation by Nuclear Corepressors and PGC-1α: Implications for Mitochondrial Quality Control and Insulin Sensitivity. PPAR Res 2012; 2012:348245. [PMID: 23304112 PMCID: PMC3523614 DOI: 10.1155/2012/348245] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 11/06/2012] [Accepted: 11/13/2012] [Indexed: 02/07/2023] Open
Abstract
The peroxisome proliferator-activated receptors (PPARs) and estrogen-related receptor (ERRα) are ligand-activated nuclear receptors that coordinately regulate gene expression. Recent evidence suggests that nuclear corepressors, NCoR, RIP140, and SMRT, repress nuclear receptors-mediated transcriptional activity on specific promoters, and thus regulate insulin sensitivity, adipogenesis, mitochondrial number, and activity in vivo. Moreover, the coactivator PGC-1α that increases mitochondrial biogenesis during exercise and calorie restriction directly regulates autophagy in skeletal muscle and mitophagy in the pathogenesis of Parkinson's disease. In this paper, we discuss the PGC-1α's novel role in mitochondrial quality control and the role of nuclear corepressors in regulating insulin sensitivity and interacting with PGC-1α.
Collapse
|
45
|
Abstract
Both genetic and environmental factors play critical roles in the development of diabetes. Epidemiological evidence and data from clinical studies suggest the persistence of a "metabolic memory" of past exposures to environmental factors or glycemic control. Epigenetic mechanisms are regarded as one of the likeliest candidates underlying these phenomena. On the other hand, owing to the recent elucidation of mechanisms that erase epigenetic marks, it has gradually become recognized that epigenetic regulation is a more dynamic process than previously thought. A technological breakthrough in epigenome research in the past decade was the development of high-throughput sequencing. This new technology lets us investigate the epigenome in a global and comprehensive manner, and provides previously unrecognized findings and insights. This review presents an overview of the recent progress in our understanding of epigenetic regulation in type 1 and type 2 diabetes research.
Collapse
Affiliation(s)
- Hironori Waki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo, Tokyo, 113-8655, Japan
| | | | | |
Collapse
|
46
|
A PPARγ-FGF1 axis is required for adaptive adipose remodelling and metabolic homeostasis. Nature 2012; 485:391-4. [PMID: 22522926 PMCID: PMC3358516 DOI: 10.1038/nature10998] [Citation(s) in RCA: 204] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 02/27/2012] [Indexed: 12/28/2022]
Abstract
Although feast and famine cycles illustrate that remodelling of adipose tissue in response to fluctuations in nutrient availability is essential for maintaining metabolic homeostasis, the underlying mechanisms remain poorly understood. Here we identify fibroblast growth factor 1 (FGF1) as a critical transducer in this process in mice, and link its regulation to the nuclear receptor PPARγ (peroxisome proliferator activated receptor γ), which is the adipocyte master regulator and the target of the thiazolidinedione class of insulin sensitizing drugs. FGF1 is the prototype of the 22-member FGF family of proteins and has been implicated in a range of physiological processes, including development, wound healing and cardiovascular changes. Surprisingly, FGF1 knockout mice display no significant phenotype under standard laboratory conditions. We show that FGF1 is highly induced in adipose tissue in response to a high-fat diet and that mice lacking FGF1 develop an aggressive diabetic phenotype coupled to aberrant adipose expansion when challenged with a high-fat diet. Further analysis of adipose depots in FGF1-deficient mice revealed multiple histopathologies in the vasculature network, an accentuated inflammatory response, aberrant adipocyte size distribution and ectopic expression of pancreatic lipases. On withdrawal of the high-fat diet, this inflamed adipose tissue fails to properly resolve, resulting in extensive fat necrosis. In terms of mechanisms, we show that adipose induction of FGF1 in the fed state is regulated by PPARγ acting through an evolutionarily conserved promoter proximal PPAR response element within the FGF1 gene. The discovery of a phenotype for the FGF1 knockout mouse establishes the PPARγ–FGF1 axis as critical for maintaining metabolic homeostasis and insulin sensitization.
Collapse
|
47
|
The in vivo role of nuclear receptor corepressors in thyroid hormone action. Biochim Biophys Acta Gen Subj 2012; 1830:3876-81. [PMID: 22801336 DOI: 10.1016/j.bbagen.2012.07.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 06/15/2012] [Accepted: 07/01/2012] [Indexed: 11/21/2022]
Abstract
BACKGROUND The thyroid hormone receptor (TR) isoforms interact with a variety of coregulators depending upon the availability of T3 to mediate their transcriptional effect. Classically, in the absence of ligand, the TRs recruit the nuclear corepressors, NCoR and SMRT, to mediate transcriptional repression on positively regulated TR target genes. However, new insight into the roles of NCoR and SMRT using in vivo models have better defined the role of nuclear corepressors both in the absence and presence of T3. SCOPE OF REVIEW This review will place the variety of in vivo nuclear corepressor mouse models developed to date in context of thyroid hormone action. Based on these models, we will also discuss how corepressor availability together with the levels of endogenous nuclear receptor ligands including T3 controls multiple signaling pathways. MAJOR CONCLUSIONS Nuclear corepressors mediate repression of positive TR targets in the absence of T3in vivo. Even more importantly they attenuate activation of these targets at the normal physiological levels of ligands by TR and other nuclear receptors. While the role of corepressors in the regulation of negative TR targets and HPT axis remains poorly understood, lack of corepressor recruitment to TR in the animals leads to a compensatory change in the set point of HPT axis that allows to balance the increased sensitivity to T3 action in other tissues. GENERAL SIGNIFICANCE Available data indicate that targeting specific interactions between corepressors and TR or other nuclear receptors presents a new therapeutic strategy for endocrine and metabolic disorders. This article is part of a Special Issue entitled Thyroid hormone signalling.
Collapse
|
48
|
Affiliation(s)
- Anthony N Hollenberg
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, USA
| |
Collapse
|
49
|
Mengeling BJ, Goodson ML, Bourguet W, Privalsky ML. SMRTε, a corepressor variant, interacts with a restricted subset of nuclear receptors, including the retinoic acid receptors α and β. Mol Cell Endocrinol 2012; 351:306-16. [PMID: 22266197 PMCID: PMC3288673 DOI: 10.1016/j.mce.2012.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 11/19/2011] [Accepted: 01/04/2012] [Indexed: 11/30/2022]
Abstract
The SMRT and NCoR corepressors bind to, and mediate transcriptional repression by, many nuclear receptors. Both SMRT and NCoR are expressed by alternative mRNA splicing, generating a series of structurally and functionally distinct corepressor "variants". We report that a splice variant of SMRT, SMRTε, recognizes a restricted subset of nuclear receptors. Unlike the other corepressor variants characterized, SMRTε possesses only a single receptor interaction domain (RID) and exhibits an unusual specificity for a subset of nuclear receptors that includes the retinoic acid receptors (RARs). The ability of the single RID in SMRTε to efficiently interact with RARs appears to be enhanced by a recently recognized β-strand/β-strand interaction between corepressor and receptor. We suggest that alternative mRNA splicing of corepressors can restrict their function to specific nuclear receptor partnerships, and we propose that this may serve to customize the transcriptional repression properties of different cell types for different biological purposes.
Collapse
Affiliation(s)
- Brenda J. Mengeling
- Department of Microbiology, One Shields Avenues, University of California at Davis, Davis, California USA 95616
| | - Michael L. Goodson
- Department of Microbiology, One Shields Avenues, University of California at Davis, Davis, California USA 95616
| | - William Bourguet
- Centre de Biochimie Structurale, INSERM, 29 rue de Navacelles, F-34090 Montpellier Cedex, France
| | - Martin L. Privalsky
- Department of Microbiology, One Shields Avenues, University of California at Davis, Davis, California USA 95616
| |
Collapse
|
50
|
NCoR1 is a conserved physiological modulator of muscle mass and oxidative function. Cell 2012; 147:827-39. [PMID: 22078881 DOI: 10.1016/j.cell.2011.10.017] [Citation(s) in RCA: 208] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 08/09/2011] [Accepted: 10/06/2011] [Indexed: 02/08/2023]
Abstract
Transcriptional coregulators control the activity of many transcription factors and are thought to have wide-ranging effects on gene expression patterns. We show here that muscle-specific loss of nuclear receptor corepressor 1 (NCoR1) in mice leads to enhanced exercise endurance due to an increase of both muscle mass and of mitochondrial number and activity. The activation of selected transcription factors that control muscle function, such as MEF2, PPARβ/δ, and ERRs, underpins these phenotypic alterations. NCoR1 levels are decreased in conditions that require fat oxidation, resetting transcriptional programs to boost oxidative metabolism. Knockdown of gei-8, the sole C. elegans NCoR homolog, also robustly increased muscle mitochondria and respiration, suggesting conservation of NCoR1 function. Collectively, our data suggest that NCoR1 plays an adaptive role in muscle physiology and that interference with NCoR1 action could be used to improve muscle function.
Collapse
|