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Park SS, Choi H, Kim SJ, Chang C, Kim E. CREB/GSK-3β signaling pathway regulates the expression of TR4 orphan nuclear receptor gene. Mol Cell Endocrinol 2016; 423:22-9. [PMID: 26762765 DOI: 10.1016/j.mce.2015.12.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 12/31/2015] [Indexed: 12/24/2022]
Abstract
In this study, we show that reduction of glucose concentration increases TR4 expression in 3T3-L1 cells via stimulation of the GSK-3β-CREB pathway. While GSK-3β and CREB increased TR4 expression in 3T3-L1 cells, inhibition of CREB expression or activity resulted in loss of GSK-3β-mediated enhancement of TR4 expression. In addition, CREB enhanced murine TR4 promoter activity via direct binding to a cAMP response element located in the promoter, and this CREB effect was further strengthened by GSK-3β. Moreover, silencing of TR4 expression by a gene-specific microRNA inhibited CREB-induced lipid accumulation in 3T3-L1 adipocytes, suggesting that TR4 could be a key mediator of CREB-induced lipogenesis.
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Affiliation(s)
- Sung-Soo Park
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, South Korea
| | - Hojung Choi
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, South Korea
| | - Seung-Jin Kim
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, South Korea
| | - Chawnshang Chang
- George Whipple Laboratory for Cancer Research, Departments of Pathology, Urology and Radiation Oncology, and Caner Center, University of Rochester Medical Center, Rochester, NY, USA
| | - Eungseok Kim
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, South Korea.
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Lala-Tabbert N, Fu D, Wiper-Bergeron N. Induction of CCAAT/Enhancer-Binding Protein β Expression With the Phosphodiesterase Inhibitor Isobutylmethylxanthine Improves Myoblast Engraftment Into Dystrophic Muscle. Stem Cells Transl Med 2016; 5:500-10. [PMID: 26941360 DOI: 10.5966/sctm.2015-0169] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/25/2015] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is the most common muscular dystrophy. Characterized by rounds of muscle degeneration and regeneration, DMD features progressive muscle wasting and is fatal. One approach for treatment is transplantation of muscle progenitor cells to repair and restore dystrophin expression to damaged muscle. However, the success of this approach has been limited by difficulties in isolating large numbers of myogenic progenitors with strong regenerative potential, poor engraftment, poor survival of donor cells, and limited migration in the diseased muscle. We demonstrate that induction of the transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) using the cyclic adenosine monophosphate phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) results in enhanced myoblast expansion in culture and increased satellite cell marker expression. When equal numbers of IBMX-treated cells were transplanted into dystrophic muscle, they contributed to muscle repair more efficiently than did vehicle-treated cells and engrafted into the satellite cell niche in higher numbers, demonstrating improved cell migration from the site of injury and enhanced survival after transplantation. Thus, pharmacologic stimulation of C/EBPβ expression reprograms myoblasts to a more stem cell-like state, promotes expansion in culture, and improves engraftment such that better transplantation outcomes are achieved. SIGNIFICANCE Duchenne muscular dystrophy is a genetic disorder for which no cure exists. One therapeutic approach is transplantation of myogenic progenitors to restore dystrophin to damaged muscle, but this approach is limited by poor engraftment of cultured myoblasts. Transient upregulation of CCAAT/enhancer-binding protein β in primary myoblasts using the phosphodiesterase isobutylmethylxanthine (IBMX) increases satellite cell marker expression in cultured myoblasts, improves their migration, and increases their survival after transplantation. When transplanted into C57BL/10ScSn-mdx/J mice , IBMX-treated myoblasts restored dystrophin expression and were able to occupy the satellite cell niche more efficiently than controls. A myoblast culture approach that reprograms myoblasts to a more primitive state, resulting in improved transplantation outcomes and reinvigorating research into myoblast transplantation as a viable therapeutic approach, is described.
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Affiliation(s)
- Neena Lala-Tabbert
- Graduate Program in Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Dechen Fu
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Nadine Wiper-Bergeron
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Abstract
It has long been established that the transcriptional activity of retinoic acid (RA) is mediated by members of the nuclear receptor family of ligand-activated transcription factors termed RA receptors (RARs). More recent observations have established that RA also activates an additional nuclear receptor, PPARβ/δ. Partitioning RA between RARs and PPARβ/δ is governed by different intracellular lipid-binding proteins: cellular RA binding protein 2 (CRABP2) delivers RA to nuclear RARs and a fatty acid binding protein (FABP5) delivers the hormone from the cytosol to nuclear PPARβ/δ. Consequently, RA signals through RARs in CRABP2-expressing cells, but activates PPARβ/δ in cells that express a high level of FABP5. RA elicits different and sometimes opposing responses in cells that express different FABP5/CRABP2 ratios because PPARβ/δ and RARs regulate the expression of distinct sets of genes. An overview of the observations that led to the discovery of this non-classical activity of RA are presented here, along with a discussion of evidence demonstrating the involvement of the dual transcriptional activities of RA in regulating energy homeostasis, insulin responses, and adipocyte and neuron differentiation.
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Interleukin-1B signalling leads to increased survival of gastric carcinoma cells through a CREB-C/EBPβ-associated mechanism. Gastric Cancer 2016; 19:74-84. [PMID: 25740226 DOI: 10.1007/s10120-014-0448-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/17/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND Polymorphisms in inflammation-related genes have been associated with a risk of gastric carcinoma (GC). However, the biological mechanisms underlying these associations are still elusive. Our objective was to determine whether chronic inflammation-associated IL1Β signalling, as seen in the context of Helicobacter pylori infection, could be linked to gastric carcinogenesis by modulating the behaviour of gastric epithelial cells. METHODS The effect of IL1B was assessed by studying the expression and activation status of the IL1Β-activated transcription factors C/EBPβ and CREB in GC cell lines. Interaction between CREB and C/EBPβ was explored through interference RNA, chromatin immunoprecipitation and chemical inhibition. CREB and C/EBPβ expression was analysed in 66 samples of primary GC and in normal gastric mucosa. GC cell growth was analysed in vitro by BrdU incorporation and in vivo employing a chicken embryo chorioallantoic membrane model. RESULTS We found that IL1B regulates the expression/activation status of both C/EBPβ and CREB in GC cells through an ERK1/2-dependent mechanism. Our results show that CREB is a direct transactivator of CEBPB, acting as an upstream effector in this regulatory mechanism. Furthermore, we found CREB to be overexpressed in 94 % of GC samples and significantly associated with C/EBPβ expression (P < 0.05). Finally, we demonstrated both in vitro and in vivo that CREB can mediate IL1B-induced GC cell proliferation. CONCLUSIONS Our results support the hypothesis that the effect of chronic inflammation on gastric carcinogenesis, as seen in the context of genetically susceptible individuals infected with Helicobacter pylori, includes the modulation of signalling pathways that regulate survival mechanisms in epithelial cells. IL1B is able to increase the expression/activation status of CREB and its target gene C/EBPβ, which are mandatory for GC cell survival. Our results may help inform new strategies for the prevention and treatment of GC, including the control of chronic inflammation.
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Wang X, Hai C. Redox modulation of adipocyte differentiation: hypothesis of "Redox Chain" and novel insights into intervention of adipogenesis and obesity. Free Radic Biol Med 2015; 89:99-125. [PMID: 26187871 DOI: 10.1016/j.freeradbiomed.2015.07.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/19/2015] [Accepted: 07/08/2015] [Indexed: 02/08/2023]
Abstract
In view of the global prevalence of obesity and obesity-associated disorders, it is important to clearly understand how adipose tissue forms. Accumulating data from various laboratories implicate that redox status is closely associated with energy metabolism. Thus, biochemical regulation of the redox system may be an attractive alternative for the treatment of obesity-related disorders. In this work, we will review the current data detailing the role of the redox system in adipocyte differentiation, as well as identifying areas for further research. The redox system affects adipogenic differentiation in an extensive way. We propose that there is a complex and interactive "redox chain," consisting of a "ROS-generating enzyme chain," "combined antioxidant chain," and "transcription factor chain," which contributes to fine-tune the regulation of ROS level and subsequent biological consequences. The roles of the redox system in adipocyte differentiation are paradoxical. The redox system exerts a "tridimensional" mechanism in the regulation of adipocyte differentiation, including transcriptional, epigenetic, and posttranslational modulations. We suggest that redoxomic techniques should be extensively applied to understand the biological effects of redox alterations in a more integrated way. A stable and standardized "redox index" is urgently needed for the evaluation of the general redox status. Therefore, more effort should be made to establish and maintain a general redox balance rather than to conduct simple prooxidant or antioxidant interventions, which have comprehensive implications.
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Affiliation(s)
- Xin Wang
- Department of Toxicology, Shaanxi Key Lab of Free Radical Biology and Medicine, the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, 710032, China.
| | - Chunxu Hai
- Department of Toxicology, Shaanxi Key Lab of Free Radical Biology and Medicine, the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, 710032, China.
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Armani A, Marzolla V, Fabbri A, Caprio M. Cellular mechanisms of MR regulation of adipose tissue physiology and pathophysiology. J Mol Endocrinol 2015; 55:R1-10. [PMID: 26272942 DOI: 10.1530/jme-15-0122] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/13/2015] [Indexed: 12/13/2022]
Abstract
In addition to the well-documented expression and activity of the mineralocorticoid receptor (MR) in the kidney, in the last decade research on MR has also revealed its important role in regulating functions of extrarenal tissues, including adipose tissue, where MR is involved in adipocyte fundamental processes such as differentiation, autophagy and adipokine secretion. MR expression is increased in adipose tissue of murine models of obesity and in obese human subjects, suggesting that over-activation of the mineralocorticoid signaling leads to dysfunctional adipocyte and associated metabolic disorders. Notably, pharmacological blockade of MR prevents metabolic dysfunctions observed in obese mice and suggests a potential therapeutic use of MR antagonists in the treatment of obesity and metabolic syndrome. However, the molecular pathways affected by MR blockade have been poorly investigated. This review summarizes the functions of MR in the adipocyte, discusses potential signaling pathways mediating MR action, and describes post-translational modifications regulating its activity.
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Affiliation(s)
- Andrea Armani
- Laboratory of Cardiovascular Endocrinology IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, Rome, Italy Endocrinology Unit Department of Systems Medicine, S. Eugenio and CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy University San Raffaele Rome, Italy
| | - Vincenzo Marzolla
- Laboratory of Cardiovascular Endocrinology IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, Rome, Italy Endocrinology Unit Department of Systems Medicine, S. Eugenio and CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy University San Raffaele Rome, Italy
| | - Andrea Fabbri
- Laboratory of Cardiovascular Endocrinology IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, Rome, Italy Endocrinology Unit Department of Systems Medicine, S. Eugenio and CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy University San Raffaele Rome, Italy
| | - Massimiliano Caprio
- Laboratory of Cardiovascular Endocrinology IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, Rome, Italy Endocrinology Unit Department of Systems Medicine, S. Eugenio and CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy University San Raffaele Rome, Italy Laboratory of Cardiovascular Endocrinology IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, Rome, Italy Endocrinology Unit Department of Systems Medicine, S. Eugenio and CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy University San Raffaele Rome, Italy
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Regnier SM, El-Hashani E, Kamau W, Zhang X, Massad NL, Sargis RM. Tributyltin differentially promotes development of a phenotypically distinct adipocyte. Obesity (Silver Spring) 2015; 23:1864-71. [PMID: 26243053 PMCID: PMC4551608 DOI: 10.1002/oby.21174] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/07/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Environmental endocrine disrupting chemicals (EDCs) are increasingly implicated in the pathogenesis of obesity. Evidence implicates various EDCs as being proadipogenic, including tributyltin (TBT), which activates the peroxisome proliferator activated receptor-γ (PPARγ). However, the conditions required for TBT-induced adipogenesis and its functional consequences are incompletely known. METHODS The costimulatory conditions necessary for preadipocyte-to-adipocyte differentiation were compared between TBT and the pharmacological PPARγ agonist troglitazone (Trog) in the 3T3-L1 cell line; basal and insulin-stimulated glucose uptake were assessed using radiolabeled 2-deoxyglucose. RESULTS TBT enhanced expression of the adipocyte marker C/EBPα with coexposure to either isobutylmethylxanthine or insulin in the absence of other adipogenic stimuli. Examination of several adipocyte-specific proteins revealed that TBT and Trog differentially affected protein expression despite comparable PPARγ stimulation. In particular, TBT reduced adiponectin expression upon maximal adipogenic stimulation. Under submaximal stimulation, TBT and Trog differentially promoted adipocyte-specific gene expression despite similar lipid accumulation. Moreover, TBT attenuated Trog-induced adipocyte gene expression under conditions of cotreatment. Finally, TBT-induced adipocytes exhibited altered glucose metabolism, with increased basal glucose uptake. CONCLUSIONS TBT-induced adipocytes are functionally distinct from those generated by a pharmacological PPARγ agonist, suggesting that obesogen-induced adipogenesis may generate dysfunctional adipocytes with the capacity to deleteriously affect global energy homeostasis.
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Affiliation(s)
- Shane M. Regnier
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, IL
- Pritzker School of Medicine, University of Chicago, Chicago, IL
| | - Essam El-Hashani
- Kovler Diabetes Center, University of Chicago, Chicago, IL
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago, Chicago, IL
| | - Wakanene Kamau
- Kovler Diabetes Center, University of Chicago, Chicago, IL
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago, Chicago, IL
| | - Xiaojie Zhang
- Kovler Diabetes Center, University of Chicago, Chicago, IL
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago, Chicago, IL
| | - Nicole L. Massad
- Kovler Diabetes Center, University of Chicago, Chicago, IL
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago, Chicago, IL
| | - Robert M. Sargis
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, IL
- Pritzker School of Medicine, University of Chicago, Chicago, IL
- Kovler Diabetes Center, University of Chicago, Chicago, IL
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago, Chicago, IL
- Corresponding Author: Robert M. Sargis, MD, PhD, University of Chicago, Section of Endocrinology, Diabetes and Metabolism, 900 E. 57 ST, KCBD 8120, Chicago, IL 60637, Phone: 773-834-1915, Fax: 773-834-0851,
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Stohn JP, Wang Q, Siviski ME, Kennedy K, Jin YR, Kacer D, DeMambro V, Liaw L, Vary CP, Rosen CJ, Prudovsky I, Lindner V. Cthrc1 controls adipose tissue formation, body composition, and physical activity. Obesity (Silver Spring) 2015; 23:1633-42. [PMID: 26148471 PMCID: PMC4509980 DOI: 10.1002/oby.21144] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/17/2015] [Accepted: 04/17/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE This study investigated the effects of loss of Cthrc1 on adipogenesis, body composition, metabolism, physical activity, and muscle physiology. METHODS Complete metabolic and activity monitoring as well as grip strength measurements and muscle myography was performed in Cthrc1 null and wildtype mice. RESULTS Compared to wildtypes, Cthrc1 null mice had similar body weights but significantly reduced energy expenditure, decreased lean mass, and increased fat mass, especially visceral fat. In vitro studies demonstrated that Cthrc1 inhibited adipocyte differentiation as well as PPAR and CREB reporter activity, while preadipocytes isolated from Cthrc1 null mice exhibited enhanced adipogenic differentiation. Voluntary physical activity in Cthrc1 null mice as assessed by wheel running was reduced to approximately half the distance covered by wildtypes. Reduced grip strength was observed in Cthrc1 null mice at the age of 15 weeks or older with reduced performance and mass of hyphenate muscle. In the brain, Cthrc1 expression was most prominent in neurons of thalamic and hypothalamic nuclei with evidence for secretion into the circulation in the median eminence. CONCLUSIONS Our data indicate that Cthrc1 regulates body composition through inhibition of adipogenesis. In addition, central Cthrc1 may be a mediator of muscle function and physical activity.
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Affiliation(s)
- J Patrizia Stohn
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Qiaozeng Wang
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Matthew E Siviski
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Kevin Kennedy
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Yong-Ri Jin
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Doreen Kacer
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Victoria DeMambro
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Lucy Liaw
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Calvin P Vary
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Clifford J Rosen
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Igor Prudovsky
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Volkhard Lindner
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
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Pulido-Salgado M, Vidal-Taboada JM, Saura J. C/EBPβ and C/EBPδ transcription factors: Basic biology and roles in the CNS. Prog Neurobiol 2015; 132:1-33. [PMID: 26143335 DOI: 10.1016/j.pneurobio.2015.06.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/08/2015] [Accepted: 06/16/2015] [Indexed: 02/01/2023]
Abstract
CCAAT/enhancer binding protein (C/EBP) β and C/EBPδ are transcription factors of the basic-leucine zipper class which share phylogenetic, structural and functional features. In this review we first describe in depth their basic molecular biology which includes fascinating aspects such as the regulated use of alternative initiation codons in the C/EBPβ mRNA. The physical interactions with multiple transcription factors which greatly opens the number of potentially regulated genes or the presence of at least five different types of post-translational modifications are also remarkable molecular mechanisms that modulate C/EBPβ and C/EBPδ function. In the second part, we review the present knowledge on the localization, expression changes and physiological roles of C/EBPβ and C/EBPδ in neurons, astrocytes and microglia. We conclude that C/EBPβ and C/EBPδ share two unique features related to their role in the CNS: whereas in neurons they participate in memory formation and synaptic plasticity, in glial cells they regulate the pro-inflammatory program. Because of their role in neuroinflammation, C/EBPβ and C/EBPδ in microglia are potential targets for treatment of neurodegenerative disorders. Any strategy to reduce C/EBPβ and C/EBPδ activity in neuroinflammation needs to take into account its potential side-effects in neurons. Therefore, cell-specific treatments will be required for the successful application of this strategy.
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Affiliation(s)
- Marta Pulido-Salgado
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain
| | - Jose M Vidal-Taboada
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain
| | - Josep Saura
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain.
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Kanao M, Kanda H, Huang W, Liu S, Yi H, Candiotti KA, Lubarsky DA, Levitt RC, Hao S. Gene Transfer of Glutamic Acid Decarboxylase 67 by Herpes Simplex Virus Vectors Suppresses Neuropathic Pain Induced by Human Immunodeficiency Virus gp120 Combined with ddC in Rats. Anesth Analg 2015; 120:1394-404. [PMID: 25851180 DOI: 10.1213/ane.0000000000000729] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Human immunodeficiency virus (HIV)-related painful sensory neuropathies primarily consist of the HIV infection-related distal sensory polyneuropathy and antiretroviral toxic neuropathies. Pharmacotherapy provides only partial relief of pain in patients with HIV/acquired immune deficiency syndrome because little is known about the exact neuropathological mechanisms for HIV-associated neuropathic pain (NP). Hypofunction of γ-aminobutyric acid (GABA) GABAergic inhibitory mechanisms has been reported after peripheral nerve injury. In this study, we tested the hypothesis that HIV gp120 combined with antiretroviral therapy reduces spinal GABAergic inhibitory tone and that restoration of GABAergic inhibitory tone will reduce HIV-related NP in a rat model. METHODS The application of recombinant HIV-1 envelope protein gp120 into the sciatic nerve plus systemic ddC (one antiretroviral drug) induced mechanical allodynia. The hind paws of rats were inoculated with replication-defective herpes simplex virus (HSV) vectors genetically encoding gad1 gene to express glutamic acid decarboxylase 67 (GAD67), an enzyme that catalyzes the decarboxylation of glutamate to GABA. Mechanical threshold was tested using von Frey filaments before and after treatments with the vectors. The expression of GAD67 in both the lumbar spinal cord and the L4-5 dorsal root ganglia was examined using western blots. The expression of mitochondrial superoxide in the spinal dorsal horn was examined using MitoSox imaging. The immunoreactivity of spinal GABA, pCREB, and pC/EBPβ was tested using immunohistochemistry. RESULTS In the gp120 with ddC-induced neuropathic pain model, GAD67 expression mediated by the HSV vector caused an elevation of mechanical threshold that was apparent on day 3 after vector inoculation. The antiallodynic effect of the single HSV vector inoculation expressing GAD67 lasted >28 days. The area under the time-effect curves in the HSV vector expressing GAD67 was increased compared with that in the control vectors (P = 0.0005). Intrathecal GABA-A/B agonists elevated mechanical threshold in the pain model. The HSV vectors expressing GAD67 reversed the lowered GABA immunoreactivity in the spinal dorsal horn in the neuropathic rats. HSV vectors expressing GAD67 in the neuropathic rats reversed the increased signals of mitochondrial superoxide in the spinal dorsal horn. The vectors expressing GAD67 reversed the upregulated immunoreactivity expression of pCREB and pC/EBPβ in the spinal dorsal horn in rats exhibiting NP. CONCLUSIONS Based on our results, we suggest that GAD67 mediated by HSV vectors acting through the suppression of mitochondrial reactive oxygen species and transcriptional factors in the spinal cord decreases pain in the HIV-related neuropathic pain model, providing preclinical evidence for gene therapy applications in patients with HIV-related pain states.
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Affiliation(s)
- Megumi Kanao
- From the *Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, Florida; †Department of Anesthesiology, Asahikawa Medical University, Asahikawa, Japan; ‡Hussman Institute of Human Genomics, University of Miami Miller School of Medicine, Miami, Florida; and §Veterans Affairs Medical Center, Miami, Florida
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Shi C, Zhang M, Tong M, Yang L, Pang L, Chen L, Xu G, Chi X, Hong Q, Ni Y, Ji C, Guo X. miR-148a is Associated with Obesity and Modulates Adipocyte Differentiation of Mesenchymal Stem Cells through Wnt Signaling. Sci Rep 2015; 5:9930. [PMID: 26001136 PMCID: PMC4441322 DOI: 10.1038/srep09930] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 02/25/2015] [Indexed: 12/19/2022] Open
Abstract
Obesity results from numerous, interacting genetic, behavioral, and physiological factors. Adipogenesis is partially regulated by several adipocyte-selective microRNAs (miRNAs) and transcription factors that regulate proliferation and differentiation of human adipose-derived mesenchymal stem cells (hMSCs-Ad). In this study, we examined the roles of adipocyte-selective miRNAs in the differentiation of hMSCs-Ad to adipocytes. Results showed that the levels of miR-148a, miR-26b, miR-30, and miR-199a increased in differentiating hMSCs-Ad. Among these miRNAs, miR-148a exhibited significant effects on increasing PPRE luciferase activity (it represents PPAR-dependent transcription, a major factor in adipogenesis) than others. Furthermore, miR-148a expression levels increased in adipose tissues from obese people and mice fed high-fat diet. miR-148a acted by suppressing its target gene, Wnt1, an endogenous inhibitor of adipogenesis. Ectopic expression of miR-148a accelerated differentiation and partially rescued Wnt1-mediated inhibition of adipogenesis. Knockdown of miR-148a also inhibited adipogenesis. Analysis of the upstream region of miR-148a locus identified a 3 kb region containing a functional cAMP-response element-binding protein (CREB) required for miR-148a expression in hMSCs-Ad. The results suggest that miR-148a is a biomarker of obesity in human subjects and mouse model, which represents a CREB-modulated miRNA that acts to repress Wnt1, thereby promoting adipocyte differentiation.
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Affiliation(s)
- Chunmei Shi
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
- Institute of Pediatrics, Nanjing Medical University,
Nanjing 210029, China
| | - Min Zhang
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
| | - Meiling Tong
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
| | - Lei Yang
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
- Institute of Pediatrics, Nanjing Medical University,
Nanjing 210029, China
| | - Lingxia Pang
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
- Institute of Pediatrics, Nanjing Medical University,
Nanjing 210029, China
| | - Ling Chen
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
- Institute of Pediatrics, Nanjing Medical University,
Nanjing 210029, China
| | - Guangfeng Xu
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
| | - Xia Chi
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
| | - Qin Hong
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
| | - Yuhui Ni
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
| | - Chenbo Ji
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
- Institute of Pediatrics, Nanjing Medical University,
Nanjing 210029, China
| | - Xirong Guo
- Department of Children Health Care, Nanjing Maternity and
Child Health Care Hospital Affiliated to Nanjing Medical University,
Nanjing 210029, China
- Institute of Pediatrics, Nanjing Medical University,
Nanjing 210029, China
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112
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Zhang J, Tang H, Deng R, Wang N, Zhang Y, Wang Y, Liu Y, Li F, Wang X, Zhou L. Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity. PLoS One 2015; 10:e0125667. [PMID: 25928058 PMCID: PMC4415922 DOI: 10.1371/journal.pone.0125667] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/23/2015] [Indexed: 11/25/2022] Open
Abstract
Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, has been demonstrated to lower blood glucose, blood lipid, and body weight in patients with type 2 diabetes mellitus. The anti-obesity effect of berberine has been attributed to its anti-adipogenic activity. However, the underlying molecular mechanism remains largely unknown. In the present study, we found that berberine significantly suppressed the expressions of CCAAT/enhancer-binding protein (C/EBP)α, peroxisome proliferators-activated receptor γ2 (PPARγ2), and other adipogenic genes in the process of adipogenesis. Berberine decreased cAMP-response element-binding protein (CREB) phosphorylation and C/EBPβ expression at the early stage of 3T3-L1 preadipocyte differentiation. In addition, CREB phosphorylation and C/EBPβ expression induced by 3-isobutyl-1-methylxanthine (IBMX) and forskolin were also attenuated by berberine. The binding activities of cAMP responsive element (CRE) stimulated by IBMX and forskolin were inhibited by berberine. The binding of phosphorylated CREB to the promoter of C/EBPβ was abrogated by berberine after the induction of preadipocyte differentiation. These results suggest that berberine blocks adipogenesis mainly via suppressing CREB activity, which leads to a decrease in C/EBPβ-triggered transcriptional cascades.
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Affiliation(s)
- Juan Zhang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hongju Tang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ruyuan Deng
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ning Wang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yuqing Zhang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yao Wang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yun Liu
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Fengying Li
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiao Wang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Libin Zhou
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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113
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Yamamoto J, Yamane T, Oishi Y, Shimizu M, Tadaishi M, Kobayashi-Hattori K. Chrysanthemum Promotes Adipocyte Differentiation, Adiponectin Secretion and Glucose Uptake. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2015; 43:255-67. [DOI: 10.1142/s0192415x15500172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The adipose tissue is an endocrine organ, and its endocrine function is closely related to type 2 diabetes. Edible Chrysanthemum morifolium Ramat. (ECM) possesses several biological properties; however, its effect on adipocytes remains unclear. We investigated the effect of the hot water extract of ECM (HW-ECM) on 3T3-L1 adipocytes. HW-ECM enhanced adipocyte differentiation, adiponectin secretion, and glucose uptake in 3T3-L1 cells. It also increased the mRNA levels of peroxisome proliferator-activated receptor γ (PPARγ), a regulator of adipocyte differentiation, adiponectin transcription, and GLUT4 expression. In addition, HW-ECM increased the mRNA levels of CCAAT/enhancer-binding protein-delta (C/EBPδ), which induces PPARγ expression, but not C/EBPβ, during early adipocyte differentiation. These results suggest that HW-ECM enhances adipocyte differentiation, adiponectin secretion, and glucose uptake through C/EBPδ-induced PPARγ expression. These effects of HW-ECM on adipocytes suggest that HW-ECM is potentially beneficial for type 2 diabetes.
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Affiliation(s)
- Junpei Yamamoto
- Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan
| | - Takumi Yamane
- Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan
| | - Yuichi Oishi
- Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan
| | - Makoto Shimizu
- Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan
| | - Miki Tadaishi
- Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan
| | - Kazuo Kobayashi-Hattori
- Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan
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114
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Abstract
The discovery of the Klotho (KL) gene, which was originally identified as a putative aging-suppressor gene, has generated tremendous interest and has advanced understanding of the aging process. In mice, the overexpression of the KL gene extends the life span, whereas mutations to the KL gene shorten the life span. The human KL gene encodes the α-Klotho protein, which is a multifunctional protein that regulates the metabolism of phosphate, calcium, and vitamin D. α-Klotho also may function as a hormone, although the α-Klotho receptor(s) has not been found. Point mutations of the KL gene in humans are associated with hypertension and kidney disease, which suggests that α-Klotho may be essential to the maintenance of normal renal function. Three α-Klotho protein types with potentially different functions have been identified: a full-length transmembrane α-Klotho, a truncated soluble α-Klotho, and a secreted α-Klotho. Recent evidence suggests that α-Klotho suppresses the insulin and Wnt signaling pathways, inhibits oxidative stress, and regulates phosphatase and calcium absorption. In this review, we provide an update on recent advances in the understanding of the molecular, genetic, biochemical, and physiological properties of the KL gene. Specifically, this review focuses on the structure of the KL gene and the factors that regulate KL gene transcription, the key sites in the regulation of α-Klotho enzyme activity, the α-Klotho signaling pathways, and the molecular mechanisms that underlie α-Klotho function. This current understanding of the molecular biology of the α-Klotho protein may offer new insights into its function and role in aging.
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Affiliation(s)
- Yuechi Xu
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
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115
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Eisenstein A, Carroll SH, Johnston-Cox H, Farb M, Gokce N, Ravid K. An adenosine receptor-Krüppel-like factor 4 protein axis inhibits adipogenesis. J Biol Chem 2015; 289:21071-81. [PMID: 24928509 DOI: 10.1074/jbc.m114.566406] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Adipogenesis represents a key process in adipose tissue development and remodeling, including during obesity. Exploring the regulation of adipogenesis by extracellular ligands is fundamental to our understanding of this process. Adenosine, an extracellular nucleoside signaling molecule found in adipose tissue depots, acts on adenosine receptors. Here we report that, among these receptors, the A2b adenosine receptor (A2bAR) is highly expressed in adipocyte progenitors. Activation of the A2bAR potently inhibits differentiation of mouse stromal vascular cells into adipocytes, whereas A2bAR knockdown stimulates adipogenesis. The A2bAR inhibits differentiation through a novel signaling cascade involving sustained expression of Krüppel-like factor 4 (KLF4), a regulator of stem cell maintenance. Knockdown of KLF4 ablates the ability of the A2bAR to inhibit differentiation. A2bAR activation also inhibits adipogenesis in a human primary preadipocyte culture system. We analyzed the A2bARKLF4 axis in adipose tissue of obese subjects and, intriguingly, found a strong correlation between A2bAR and KLF4 expression in both subcutaneous and visceral human fat. Hence, our study implicates the A2bAR as a regulator of adipocyte differentiation and the A2bAR-KLF4 axis as a potentially significant modulator of adipose biology.
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116
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ATM Regulates Adipocyte Differentiation and Contributes to Glucose Homeostasis. Cell Rep 2015; 10:957-967. [DOI: 10.1016/j.celrep.2015.01.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 12/16/2014] [Accepted: 01/09/2015] [Indexed: 01/13/2023] Open
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117
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Kang SI, Shin HS, Kim SJ. Sinensetin enhances adipogenesis and lipolysis by increasing cyclic adenosine monophosphate levels in 3T3-L1 adipocytes. Biol Pharm Bull 2015; 38:552-8. [PMID: 25735898 DOI: 10.1248/bpb.b14-00700] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sinensetin is a rare polymethoxylated flavone (PMF) found in certain citrus fruits. In this study, we investigated the effects of sinensetin on lipid metabolism in 3T3-L1 cells. Sinensetin promoted adipogenesis in 3T3-L1 preadipocytes growing in incomplete differentiation medium, which did not contain 3-isobutyl-1-methylxanthine. Sinensetin up-regulated expression of the adipogenic transcription factors peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein (C/EBP) α, and sterol regulatory element-binding protein 1c. It also potentiated expression of C/EBPβ and activation of cAMP-responsive element-binding protein. Sinensetin enhanced activation of protein kinase A and increased intracellular cAMP levels in 3T3-L1 preadipocytes. In mature 3T3-L1 adipocytes, sinensetin stimulated lipolysis via a cAMP pathway. Taken together, these results suggest that sinensetin enhances adipogenesis and lipolysis by increasing cAMP levels in adipocytes.
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118
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Arnaboldi L, Corsini A. Could changes in adiponectin drive the effect of statins on the risk of new-onset diabetes? The case of pitavastatin. ATHEROSCLEROSIS SUPP 2015; 16:1-27. [DOI: 10.1016/s1567-5688(14)70002-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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119
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Nishizuka M, Hayashi T, Asano M, Osada S, Imagawa M. KCNK10, a tandem pore domain potassium channel, is a regulator of mitotic clonal expansion during the early stage of adipocyte differentiation. Int J Mol Sci 2014; 15:22743-56. [PMID: 25501330 PMCID: PMC4284734 DOI: 10.3390/ijms151222743] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/10/2014] [Accepted: 11/26/2014] [Indexed: 01/13/2023] Open
Abstract
KCNK10, a member of tandem pore domain potassium channel family, gives rise to leak K+ currents. It plays important roles in stabilizing the negative resting membrane potential and in counterbalancing depolarization. We previously demonstrated that kcnk10 expression is quickly elevated during the early stage of adipogenesis of 3T3-L1 cells and that reduction of kcnk10 expression inhibits adipocyte differentiation. However, the molecular mechanism of KCNK10 in adipocyte differentiation remains unclear. Here we revealed that kcnk10 is induced by 3-isobutyl-1-methylxanthine, a cyclic nucleotide phosphodiesterase inhibitor and a potent inducer of adipogenesis, during the early stage of adipocyte differentiation. We also demonstrated that KCNK10 functions as a positive regulator of mitotic clonal expansion (MCE), a necessary process for terminal differentiation. The reduction of kcnk10 expression repressed the expression levels of CCAAT/enhancer-binding protein β (C/EBPβ) and C/EBPδ as well as the phosphorylation level of Akt during the early phase of adipogenesis. In addition, knockdown of kcnk10 expression suppressed insulin-induced Akt phosphorylation. These results indicate that KCNK10 contributes to the regulation of MCE through the control of C/EBPβ and C/EBPδ expression and insulin signaling.
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Affiliation(s)
- Makoto Nishizuka
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Takahiro Hayashi
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Mami Asano
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Shigehiro Osada
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Masayoshi Imagawa
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
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120
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Gormand A, Berggreen C, Amar L, Henriksson E, Lund I, Albinsson S, Göransson O. LKB1 signalling attenuates early events of adipogenesis and responds to adipogenic cues. J Mol Endocrinol 2014; 53:117-30. [PMID: 24859970 DOI: 10.1530/jme-13-0296] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
cAMP-response element-binding protein (CREB) is required for the induction of adipogenic transcription factors such as CCAAT/enhancer-binding proteins (C/EBPs). Interestingly, it is known from studies in other tissues that LKB1 and its substrates AMP-activated protein kinase (AMPK) and salt-inducible kinases (SIKs) negatively regulate gene expression by phosphorylating the CREB co-activator CRTC2 and class IIa histone deacetylases (HDACs), which results in their exclusion from the nucleus where they co-activate or inhibit their targets. In this study, we show that AMPK/SIK signalling is acutely attenuated during adipogenic differentiation of 3T3-L1 preadipocytes, which coincides with the dephosphorylation and nuclear translocation of CRTC2 and HDAC4. When subjected to differentiation, 3T3-L1 preadipocytes in which the expression of LKB1 was stably reduced using shRNA (Lkb1-shRNA), as well as Lkb1-knockout mouse embryonic fibroblasts (Lkb1(-/-) MEFs), differentiated more readily into adipocyte-like cells and accumulated more triglycerides compared with scrambled-shRNA-expressing 3T3-L1 cells or Wt MEFs. In addition, the phosphorylation of CRTC2 and HDAC4 was reduced, and the mRNA expression of adipogenic transcription factors Cebpa, peroxisome proliferator-activated receptor γ (Pparg) and adipocyte-specific proteins such as hormone-sensitive lipase (HSL), fatty acid synthase (FAS), aP2, GLUT4 and adiponectin was increased in the absence of LKB1. The mRNA and protein expression of Ddit3/CHOP10, a dominant-negative member of the C/EBP family, was reduced in Lkb1-shRNA-expressing cells, providing a potential mechanism for the up-regulation of Pparg and Cebpa expression. These results support the hypothesis that LKB1 signalling keeps preadipocytes in their non-differentiated form.
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Affiliation(s)
- Amélie Gormand
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
| | - Christine Berggreen
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
| | - Lahouari Amar
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
| | - Emma Henriksson
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
| | - Ingrid Lund
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
| | - Sebastian Albinsson
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
| | - Olga Göransson
- Department of Experimental Medical ScienceLund University, BMC C11, 221 84 Lund, SwedenDepartment of BiomedicineKarolinska Institute, Stockholm, Sweden
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121
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A novel PPARγ2 modulator sLZIP controls the balance between adipogenesis and osteogenesis during mesenchymal stem cell differentiation. Cell Death Differ 2014; 21:1642-55. [PMID: 24948012 DOI: 10.1038/cdd.2014.80] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 04/22/2014] [Accepted: 05/09/2014] [Indexed: 02/08/2023] Open
Abstract
Mesenchymal stem cells (MSCs), also known as multipotent stromal cells, are used in clinical trials. However, the use of MSCs for medical treatment of patients poses a potential problem due to the possibility of transdifferentiation into unwanted tissues. Disruption of the balance during MSC differentiation leads to obesity, skeletal fragility, and osteoporosis. Differentiation of MSCs into either adipocytes or osteoblasts is transcriptionally regulated by the two key transcription factors PPARγ2 and Runx2. PPARγ2 is highly expressed during adipocyte differentiation and regulates expression of genes involved in adipogenesis. Runx2 induces osteogenic gene expression and, thereby, increases osteoblast differentiation. Although transcriptional modulation of PPARγ2 has been investigated in adipogenesis, the underlying molecular mechanisms to control the balance between adipogenesis and osteogenesis in MSCs remain unclear. In this study, the role of sLZIP in regulation of PPARγ2 transcriptional activation was investigated along with sLZIP's involvement in differentiation of MSCs into adipocytes and osteoblasts. sLZIP interacts with PPARγ2 and functions as a corepressor of PPARγ2. sLZIP enhances formation of the PPARγ2 corepressor complex through specific interaction with HDAC3, resulting in suppression of PPARγ2 transcriptional activity. We found that sLZIP prevents expression of PPARγ2 target genes and adipocyte differentiation both in vitro and in vivo. sLZIP also upregulates Runx2 transcriptional activity via inhibition of PPARγ2 activity, and promotes osteoblast differentiation. sLZIP transgenic mice exhibited enhanced bone mass and density, compared with wild-type mice. These results indicate that sLZIP has a critical role in the regulation of osteogenesis and bone development. However, sLZIP does not affect chondrogenesis and osteoclastogenesis. We propose that sLZIP is a novel PPARγ2 modulator for control of the balance between adipogenesis and osteogenesis during MSC differentiation, and that sLZIP can be used as a therapeutic target molecule for treatment of obesity, osteodystrophy, and osteoporosis.
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122
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Zhu Y, Zhang X, Ding X, Wang H, Chen X, Zhao H, Jia Y, Liu S, Liu Y. miR-27 inhibits adipocyte differentiation via suppressing CREB expression. Acta Biochim Biophys Sin (Shanghai) 2014; 46:590-6. [PMID: 24903074 DOI: 10.1093/abbs/gmu036] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
miR-27 plays a negative role in the regulation of adipogenesis. However, the molecular mechanism still remains to be clarified. In the present study, we found that miR-27 inhibits adipogenesis partially by repressing the early adipogenic transcription factor cAMP response element-binding protein by directly targeting its 3' untranslated region. In addition, we demonstrated that tumor necrosis factor-α (TNF-α) treatment up-regulates miR-27 through the NF-κB pathway. Furthermore, anti-miR-27 reduces the TNF-α-induced inhibition of adipogenesis. Simultaneously, the levels of miR-27 expression were decreased in mature adipocytes of obese mice when compared with lean mice. Our data revealed a novel mechanism of miR-27 in the regulation of adipogenesis.
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Affiliation(s)
- Yingjie Zhu
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Xiaodong Zhang
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Xingpo Ding
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Huichao Wang
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Xiantao Chen
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Hanzheng Zhao
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Yudong Jia
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
| | - Sanhong Liu
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200031, China
| | - Youwen Liu
- Luoyang Orthopedic-Traumatological Hospital, Luoyang 471000, China
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123
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Yu K, Mo D, Wu M, Chen H, Chen L, Li M, Chen Y. Activating transcription factor 4 regulates adipocyte differentiation via altering the coordinate expression of CCATT/enhancer binding protein β and peroxisome proliferator-activated receptor γ. FEBS J 2014; 281:2399-409. [PMID: 24673832 DOI: 10.1111/febs.12792] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 03/18/2014] [Accepted: 03/24/2014] [Indexed: 12/28/2022]
Abstract
Adipose tissue is crucial for energy homeostasis and is a topic interest with respect to investigating the regulation of adipose tissue formation for the ever-increasing health concerns of obesity and type 2 diabetes. Adipocyte differentiation is tightly regulated by the characteristic sequential expression change of adipocyte genes, including members of the CCATT/enhancer binding protein (C/EBP) family of transcription factors, peroxisome proliferator-activated receptor γ and tribbles homolog 3. In the present study, we demonstrate that C/EBPβ and peroxisome proliferator-activated receptor γ (but not tribbles homolog 3) are targeted for activation by activating transcription factor 4 (ATF4), a member of cAMP response element-binding/activator transcription factor family. Importantly, overexpression of ATF4 in 3T3-L1 cells enhanced adipogenesis, whereas small-interfering ATF4 blocked conversion of preadipocytes to adipocytes. These findings were accomplished by altering the coordinate expression of adipogenic transcription factors. Taken together, our results suggest that ATF4 is a positive regulator of adipocyte differentiation. This notion is also supported by the results of the present study showing that the expression of ATF4 is induced during adipocyte differentiation. Thus, ATF4 could be an important regulator of energy homeostasis.
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Affiliation(s)
- Kaifan Yu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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124
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Nosrati N, Kapoor NR, Kumar V. Combinatorial action of transcription factors orchestrates cell cycle-dependent expression of the ribosomal protein genes and ribosome biogenesis. FEBS J 2014; 281:2339-52. [DOI: 10.1111/febs.12786] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 03/01/2014] [Accepted: 03/17/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Nagisa Nosrati
- Virology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
| | - Neetu R. Kapoor
- Virology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
| | - Vijay Kumar
- Virology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
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125
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Isolation, culture and differentiation of duck (Anas platyrhynchos) preadipocytes. Cytotechnology 2014; 67:773-81. [PMID: 24696190 DOI: 10.1007/s10616-014-9715-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 03/04/2014] [Indexed: 02/06/2023] Open
Abstract
In the present study, we isolated preadipocytes from the adipose tissue of Peking duck and subsequently cultured them in vitro. Cell counting kit-8 assay was employed to establish the growth curve of duck primary preadipocytes. Meanwhile, after the cells reaching full confluency, they were induced to differentiate into mature adipocytes by the addition of a cocktail containing dexamethasone, insulin, 3-isobutyl-1-methylxanthine, and oleic acid for 8 days. Successful differentiation was demonstrated by the development of lipid droplets and the expression of key marker genes including peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein-α (CEBP/α) and adipocyte fatty acid-binding protein (FABP4). Our results showed that duck primary preadipocytes began to adhere 12 h after seeding as short spindle shapes or litter triangles, which grew quickly 3 days post attachment and maintained stable after day 7. After 8 days the preadipocytes were induced to differentiate into mature adipocytes, which were stained red by oil red O. Additionally, it showed that during preadipocyte differentiation PPARγ mRNA was highly expressed at day 3, while CEBP/α and FABP4 mRNA peaked at day 5 and 8, respectively. These results indicate that we have successfully isolated and cultured Peking duck preadipocytes and successfully induced them to differentiate into mature adipocytes. This work could lay a foundation for further research into waterfowl adipogenesis.
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126
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Rivera-Gonzalez G, Shook B, Horsley V. Adipocytes in skin health and disease. Cold Spring Harb Perspect Med 2014; 4:4/3/a015271. [PMID: 24591537 DOI: 10.1101/cshperspect.a015271] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Adipocytes are intimately associated with the dermal compartment of the skin, existing in a specialized dermal depot and displaying dynamic changes in size during tissue homeostasis. However, the roles of adipocytes in cutaneous biology and disease are not well understood. Traditionally, adipocytes within tissues were thought to act as reservoirs of energy, as thermal, or as structural support. In this review, we discuss recent studies revealing the cellular basis of the dynamic development and regenerative capacity of dermal adipocytes associated with the hair cycle and following injury. We discuss and speculate on potential roles of dermal adipocytes in cutaneous biology with an emphasis on communication during hair follicle growth and wound healing. Finally, we explore how alterations in the dermal adipose tissue may support clinical manifestations of cutaneous diseases such as lipodystrophy, obesity, and alopecia.
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Affiliation(s)
- Guillermo Rivera-Gonzalez
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520
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127
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Eisenstein A, Ravid K. G protein-coupled receptors and adipogenesis: a focus on adenosine receptors. J Cell Physiol 2014; 229:414-21. [PMID: 24114647 DOI: 10.1002/jcp.24473] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 09/12/2013] [Indexed: 12/20/2022]
Abstract
G-protein coupled receptors (GPCRs) are a large family of proteins that coordinate extracellular signals to produce physiologic outcomes. Adenosine receptors (AR) are one class of GPCRs that have been shown to regulate functions as diverse as inflammation, blood flow, and cellular differentiation. Adenosine signals through four GPCRs that either inhibit (A1AR and A3AR) or activate (A2aAR and A2bAR) adenylyl cyclase. This review will focus on the role of GPCRs, and in particular, adenosine receptors, in adipogenesis. Preadipocytes differentiate to mature adipocytes as the adipose tissue expands to compensate for the consumption of excess nutrients. These newly generated adipocytes contribute to maintaining metabolic homeostasis. Understanding the key drivers of this differentiation process can aid the development of therapeutics to combat the growing obesity epidemic and associated metabolic consequences. Although much literature has covered the transcriptional events that culminate in the formation of an adipocyte, less focus has been on receptor-mediated extracellular signals that direct this process. This review will highlight GPCRs and their downstream messengers as significant players controlling adipocyte differentiation.
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Affiliation(s)
- Anna Eisenstein
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts
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LeBlanc SE, Wu Q, Barutcu AR, Xiao H, Ohkawa Y, Imbalzano AN. The PPARγ locus makes long-range chromatin interactions with selected tissue-specific gene loci during adipocyte differentiation in a protein kinase A dependent manner. PLoS One 2014; 9:e86140. [PMID: 24465921 PMCID: PMC3896465 DOI: 10.1371/journal.pone.0086140] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 12/05/2013] [Indexed: 02/05/2023] Open
Abstract
Differentiation signaling results in reprogramming of cellular gene expression that leads to morphological changes and functional specialization of a precursor cell. This global change in gene expression involves temporal regulation of differentiation-specific genes that are located throughout the genome, raising the idea that genome structure may also be re-organized during cell differentiation to facilitate regulated gene expression. Using in vitro adipocyte differentiation as a model, we explored whether gene organization within the nucleus is altered upon exposure of precursor cells to signaling molecules that induce adipogenesis. The peroxisome proliferator-activated receptor gamma (PPARγ) nuclear hormone receptor is a master determinant of adipogenesis and is required for adipose differentiation. We utilized the chromosome conformation capture (3C) assay to determine whether the position of the PPARγ locus relative to other adipogenic genes is changed during differentiation. We report that the PPARγ2 promoter is transiently positioned in proximity to the promoters of genes encoding adipokines and lipid droplet associated proteins at 6 hours post-differentiation, a time that precedes expression of any of these genes. In contrast, the PPARγ2 promoter was not in proximity to the EF1α promoter, which drives expression of a constitutively active, housekeeping gene that encodes a translation elongation factor, nor was the PPARγ2 promoter in proximity to the promoter driving the expression of the C/EBPα regulatory protein. The formation of the long-range, intergenic interactions involving the PPARγ2 promoter required the regulatory factor C/EBPβ, elevated cyclic AMP (cAMP) levels, and protein kinase A (PKA) signaling. We conclude that genome organization is dynamically remodeled in response to adipogenic signaling, and we speculate that these transient inter-genic interactions may be formed for the purposes of selecting some of the transcriptionally silent tissue-specific loci for subsequent transcriptional activation.
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Affiliation(s)
- Scott E. LeBlanc
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Qiong Wu
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - A. Rasim Barutcu
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Hengyi Xiao
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Laboratory of Aging Research, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Yasuyuki Ohkawa
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Department of Advanced Medical Initiatives, JST-CREST, Faculty of Medicine, Kyushu University, Fukuoka, Japan
| | - Anthony N. Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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129
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Choi K, Ghaddar B, Moya C, Shi H, Sridharan GV, Lee K, Jayaraman A. Analysis of transcription factor network underlying 3T3-L1 adipocyte differentiation. PLoS One 2014; 9:e100177. [PMID: 25075860 PMCID: PMC4116336 DOI: 10.1371/journal.pone.0100177] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 05/23/2014] [Indexed: 11/28/2022] Open
Abstract
Lipid accumulation in adipocytes reflects a balance between enzymatic pathways leading to the formation and breakdown of esterified lipids, primarily triglycerides. This balance is extremely important, as both high and low lipid levels in adipocytes can have deleterious consequences. The enzymes responsible for lipid synthesis and breakdown (lipogenesis and lipolysis, respectively) are regulated through the coordinated actions of several transcription factors (TFs). In this study, we examined the dynamics of several key transcription factors (TFs) - PPARγ, C/EBPβ, CREB, NFAT, FoxO1, and SREBP-1c - during adipogenic differentiation (week 1) and ensuing lipid accumulation. The activation profiles of these TFs at different times following induction of adipogenic differentiation were quantified using 3T3-L1 reporter cell lines constructed to secrete the Gaussia luciferase enzyme upon binding of a TF to its DNA binding element. The dynamics of the TFs was also modeled using a combination of logical gates and ordinary differential equations, where the logical gates were used to explore different combinations of activating inputs for PPARγ, C/EBPβ, and SREBP-1c. Comparisons of the experimental profiles and model simulations suggest that SREBP-1c could be independently activated by either insulin or PPARγ, whereas PPARγ activation required both C/EBPβ as well as a putative ligand. Parameter estimation and sensitivity analysis indicate that feedback activation of SREBP-1c by PPARγ is negligible in comparison to activation of SREBP-1c by insulin. On the other hand, the production of an activating ligand could quantitatively contribute to a sustained elevation in PPARγ activity.
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Affiliation(s)
- KyungOh Choi
- Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Bassel Ghaddar
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
| | - Colby Moya
- Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Hai Shi
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
| | - Gautham V. Sridharan
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
| | - Kyongbum Lee
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
- * E-mail: (AJ); (KL)
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (AJ); (KL)
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130
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Arçari DP, Santos JC, Gambero A, Ribeiro ML. The in vitro and in vivo effects of yerba mate (Ilex paraguariensis) extract on adipogenesis. Food Chem 2013; 141:809-15. [DOI: 10.1016/j.foodchem.2013.04.062] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/12/2013] [Accepted: 04/19/2013] [Indexed: 01/11/2023]
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131
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Chen Y, Xue P, Hou Y, Zhang H, Zheng H, Zhou T, Qu W, Teng W, Zhang Q, Andersen ME, Pi J. Isoniazid suppresses antioxidant response element activities and impairs adipogenesis in mouse and human preadipocytes. Toxicol Appl Pharmacol 2013; 273:435-41. [PMID: 24128855 DOI: 10.1016/j.taap.2013.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/26/2013] [Accepted: 10/03/2013] [Indexed: 02/06/2023]
Abstract
Transcriptional signaling through the antioxidant response element (ARE), orchestrated by the Nuclear factor E2-related factor 2 (Nrf2), is a major cellular defense mechanism against oxidative or electrophilic stress. Here, we reported that isoniazid (INH), a widely used antitubercular drug, displays a substantial inhibitory property against ARE activities in diverse mouse and human cells. In 3T3-L1 preadipocytes, INH concentration-dependently suppressed the ARE-luciferase reporter activity and mRNA expression of various ARE-dependent antioxidant genes under basal and oxidative stressed conditions. In keeping with our previous findings that Nrf2-ARE plays a critical role in adipogenesis by regulating expression of CCAAT/enhancer-binding protein β (C/EBPβ) and peroxisome proliferator-activated receptor γ (PPARγ), suppression of ARE signaling by INH hampered adipogenic differentiation of 3T3-L1 cells and human adipose-derived stem cells (ADSCs). Following adipogenesis induced by hormonal cocktails, INH-treated 3T3-L1 cells and ADSCs displayed significantly reduced levels of lipid accumulation and attenuated expression of C/EBPα and PPARγ. Time-course studies in 3T3-L1 cells revealed that inhibition of adipogenesis by INH occurred in the early stage of terminal adipogenic differentiation, where reduced expression of C/EBPβ and C/EBPδ was observed. To our knowledge, the present study is the first to demonstrate that INH suppresses ARE signaling and interrupts with the transcriptional network of adipogenesis, leading to impaired adipogenic differentiation. The inhibition of ARE signaling may be a potential underlying mechanism by which INH attenuates cellular antioxidant response contributing to various complications.
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Affiliation(s)
- Yanyan Chen
- Institute for Chemical Safety Sciences, The Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709, USA; The First Affiliated Hospital, China Medical University, Shenyang 110001, China
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132
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Ragni E, Viganò M, Parazzi V, Montemurro T, Montelatici E, Lavazza C, Budelli S, Vecchini A, Rebulla P, Giordano R, Lazzari L. Adipogenic potential in human mesenchymal stem cells strictly depends on adult or foetal tissue harvest. Int J Biochem Cell Biol 2013; 45:2456-66. [PMID: 23942228 DOI: 10.1016/j.biocel.2013.07.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/08/2013] [Accepted: 07/31/2013] [Indexed: 12/25/2022]
Abstract
Cell-based therapies promise important developments for regenerative medicine purposes. Adipose tissue and the adipogenic process has become central to an increasing number of translational efforts in addition to plastic and reconstructive surgical applications. In recent experimental clinical trials, human mesenchymal stem cells (MSC) have been proven to be well tolerated because of their low immunoreactivity. MSC are multipotent cells found among mature cells in different tissues and organs with the potentiality to differentiate in many cell types, including osteocytes, chondrocytes and adipocytes, thus being a suitable cell source for tissue engineering strategies. We compared the adipogenic potential of MSC originated from two adult sources as fat pads and bone marrow, and from four foetal sources as umbilical cord blood, Wharton's jelly, amniotic fluid and preterm umbilical cord perivascular cells. Surprisingly, adult MSC displayed higher differentiation capacities confirmed by gene expression analysis on a selected panel of adipogenesis-related genes. Further, an in-depth molecular analysis highlighted the early and vigorous activation of the PPARγ transcription factor-cascade in adipose-derived MSC that resulted to be both delayed and reduced in foetal MSC accounting for their lack of adipogenic potential. Thus, MSC show a different degree of phenotypic plasticity depending on the source tissue, that should be taken into consideration for the selection of the most appropriate MSC type for specific tissue regeneration purposes.
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Affiliation(s)
- Enrico Ragni
- Cell Factory "Franco Calori", Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122 Milano, Italy.
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133
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Chen L, Song J, Cui J, Hou J, Zheng X, Li C, Liu L. microRNAs regulate adipocyte differentiation. Cell Biol Int 2013; 37:533-46. [PMID: 23504919 DOI: 10.1002/cbin.10063] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Accepted: 01/22/2013] [Indexed: 02/05/2023]
Abstract
The number of adipocytes is relevant to the extent of differentiation from pluripotent stem cells into pre-adipocytes, whereas the size of adipocytes relates to the extent of differentiation from pre-adipocytes into mature fat cells and the accumulation of triglyceride. Investigation of the molecular regulatory mechanism of adipocyte differentiation is not only essential for understanding the physiological processes of adipogenesis, but it is also important for identifying new biomarkers and therapeutic targets for some metabolic diseases, such as obesity and diabetes. microRNAs (miRNAs) appear to play important roles in adipocyte differentiation. During adipogenesis, miRNAs can accelerate or inhibit adipocyte differentiation by acting on transcription factors, regulating signalling pathways related to adipogenesis, or blocking the mitotic clonal expansion stage, thus regulating adipocyte development. The regulatory role of some miRNAs varies in different species or different cells. In this review, the biological characteristics of miRNA and the adipocyte differentiation process are concisely discussed. Recent advances in our understanding of the role of miRNAs in adipocytes development or adipogenesis are discussed.
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Affiliation(s)
- Lin Chen
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
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134
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Honda T, Ishii A, Inui M. Regulation of adipocyte differentiation of 3T3-L1 cells by PDZRN3. Am J Physiol Cell Physiol 2013; 304:C1091-7. [DOI: 10.1152/ajpcell.00343.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PDZRN3, a member of the PDZRN (or LNX) family of proteins, is essential for the differentiation of mesenchymal stem cells into myotubes, but it plays an inhibitory role in the differentiation of these cells into osteoblasts. Given that mesenchymal stem cells also differentiate into adipocytes, we examined the possible role of PDZRN3 in adipogenesis in mouse 3T3-L1 preadipocytes. The expression of PDZRN3 decreased at both the mRNA and protein levels during adipogenic differentiation. RNAi-mediated depletion of PDZRN3 enhanced the differentiation of 3T3-L1 cells into adipocytes as assessed on the basis of lipid accumulation. The upregulation of aP2 and CCAAT/enhancer-binding protein (C/EBP)-β during adipocyte differentiation was also enhanced in the PDZRN3-depleted cells, as was the induction of peroxisome proliferator-activated receptor-γ (PPARγ), an upstream regulator of aP2 and C/EBPα, at both the mRNA and protein levels. Among transcription factors that control the expression of PPARγ, we found that STAT5b, but not STAT5a, was upregulated in PDZRN3-depleted cells at both mRNA and protein levels. Tyrosine phosphorylation of STAT5b, but not that of STAT5a, was also enhanced at an early stage of differentiation by PDZRN3 depletion. In addition, the expression of C/EBPβ during the induction of differentiation was enhanced at the mRNA and protein levels in PDZRN3-depleted cells. Our results thus suggest that PDZRN3 negatively regulates adipogenesis in 3T3-L1 cells through downregulation of STAT5b and C/EBPβ and consequent suppression of PPARγ expression.
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Affiliation(s)
- Takeshi Honda
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Aiko Ishii
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Makoto Inui
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
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135
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Hirai H, Kamio N, Huang G, Matsusue A, Ogino S, Kimura N, Satake S, Ashihara E, Imanishi J, Tenen DG, Maekawa T. Cyclic AMP responsive element binding proteins are involved in 'emergency' granulopoiesis through the upregulation of CCAAT/enhancer binding protein β. PLoS One 2013; 8:e54862. [PMID: 23382991 PMCID: PMC3559830 DOI: 10.1371/journal.pone.0054862] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 12/19/2012] [Indexed: 11/18/2022] Open
Abstract
In contrast to the definitive role of the transcription factor, CCAAT/Enhancer binding protein α (C/EBPα), in steady-state granulopoiesis, previous findings have suggested that granulopoiesis during emergency situations, such as infection, is dependent on C/EBPβ. In this study, a novel lentivirus-based reporter system was developed to elucidate the molecular switch required for C/EBPβ-dependency. The results demonstrated that two cyclic AMP responsive elements (CREs) in the proximal promoter region of C/EBPβ were involved in the positive regulation of C/EBPβ transcription during granulocyte-macrophage colony-stimulating factor (GM-CSF)–induced differentiation of bone marrow cells. In addition, the transcripts of CRE binding (CREB) family proteins were readily detected in hematopoietic stem/progenitor cells. CREB was upregulated, phosphorylated and bound to the CREs in response to GM-CSF stimulation. Retroviral transduction of a dominant negative CREB mutant reduced C/EBPβ mRNA levels and significantly impaired the proliferation/differentiation of granulocyte precursors, while a constitutively active form of CREB facilitated C/EBPβ transcription. These data suggest that CREB proteins are involved in the regulation of granulopoiesis via C/EBPβ upregulation.
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Affiliation(s)
- Hideyo Hirai
- Department of Transfusion Medicine and Cell Therapy, Kyoto University Hospital, Kyoto, Japan.
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136
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Abstract
The two types of adipose tissue in humans, white and brown, have distinct developmental origins and functions. Human white adipose tissue plays a pivotal role in maintaining whole-body energy homeostasis by storing triglycerides when energy is in surplus, releasing free fatty acids as a fuel during energy shortage, and secreting adipokines that are important for regulating lipid and glucose metabolism. The size of white adipose mass needs to be kept at a proper set point. Dramatic expansion of white fat mass causes obesity—now become a global epidemic disease—and increases the risk for the development of many life-threatening diseases. The absence of white adipose tissue or abnormal white adipose tissue redistribution leads to lipodystrophy, a condition often associated with metabolic disorders. Brown adipose tissue is a thermogenic organ whose mass is inversely correlated with body mass index and age. Therapeutic approaches targeting adipose tissue have been proven to be effective in improving obesity-related metabolic disorders, and promising new therapies could be developed in the near future.
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Affiliation(s)
- Bin Feng
- Hallett Center for Diabetes and Endocrinology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA
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137
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Zhou H, Kaplan T, Li Y, Grubisic I, Zhang Z, Wang PJ, Eisen MB, Tjian R. Dual functions of TAF7L in adipocyte differentiation. eLife 2013; 2:e00170. [PMID: 23326641 PMCID: PMC3539393 DOI: 10.7554/elife.00170] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Accepted: 11/09/2012] [Indexed: 12/22/2022] Open
Abstract
The diverse transcriptional mechanisms governing cellular differentiation and development of mammalian tissue remains poorly understood. Here we report that TAF7L, a paralogue of TFIID subunit TAF7, is enriched in adipocytes and white fat tissue (WAT) in mouse. Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well. Ectopic expression of TAF7L in myoblasts reprograms these muscle precursors into adipocytes upon induction. Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPARγ at enhancers and TBP/Pol II at core promoters. In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPARγ. These findings suggest that TAF7L plays an integral role in adipocyte gene expression by targeting enhancers as a cofactor for PPARγ and promoters as a component of the core transcriptional machinery.DOI:http://dx.doi.org/10.7554/eLife.00170.001.
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Affiliation(s)
- Haiying Zhou
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
- Li Ka Shing Center For Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Berkeley, Berkeley, United States
| | - Tommy Kaplan
- Department of Molecular and Cell Biology, California Institute of Quantitative Biosciences, University of California, Berkeley, Berkeley, United States
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yan Li
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ivan Grubisic
- Li Ka Shing Center For Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Berkeley, Berkeley, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, Department of Molecular and Cell Biology, California Institute of Quantitative Biosciences, University of California, Berkeley, Berkeley, United States
| | - Zhengjian Zhang
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - P Jeremy Wang
- Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, United States
| | - Michael B Eisen
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
- Department of Molecular and Cell Biology, California Institute of Quantitative Biosciences, University of California, Berkeley, Berkeley, United States
| | - Robert Tjian
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
- Li Ka Shing Center For Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Berkeley, Berkeley, United States
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138
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Peverelli E, Ermetici F, Corbetta S, Gozzini E, Avagliano L, Zappa MA, Bulfamante G, Beck-Peccoz P, Spada A, Mantovani G. PKA regulatory subunit R2B is required for murine and human adipocyte differentiation. Endocr Connect 2013; 2:196-207. [PMID: 24145613 PMCID: PMC3847920 DOI: 10.1530/ec-13-0049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ADIPOGENESIS IS A COMPLEX PROCESS MODULATED BY SEVERAL FACTORS, INCLUDING CAMP SIGNALING. THE MAIN CAMP TARGET IS PROTEIN KINASE A (PKA), A TETRAMERIC ENZYME WITH FOUR REGULATORY SUBUNITS SHOWING TISSUE-SPECIFIC EXPRESSION AND FUNCTION: PRKAR2B is the main regulatory subunit in adipose tissue in mice and in adult humans. This study aimed to evaluate the expression of PKA regulatory subunits in human adipose tissue during fetal development and to investigate their role in the differentiation of 3T3-L1 and primary human preadipocytes. The expression of PKA regulatory subunits was evaluated in fetal adipose tissue (immunohistochemistry) and in cultured 3T3-L1 and primary human preadipocytes (western blot analysis). Cultured cells were transiently transfected with siRNA against PRKAR2B and induced to differentiate. Differentiation was evaluated by intracellular triglyceride staining (Oil Red O) and expression of molecular markers of adipocyte differentiation. In this study, we found that PRKAR2B is the main regulatory subunit in human adipose tissue during fetal development, from 12 weeks of gestation to the end of gestation, as well as in 3T3-L1 and primary human preadipocytes. The expression of PRKAR2B increases progressively during in vitro differentiation. The silencing of PRKAR2B abolishes the increase in the expression of peroxisome proliferator-activated receptor gamma (PPARγ (PPARG)), fatty acid synthase, aP2 (FABP4), and lipoprotein lipase, as well as intracellular triglyceride accumulation, resulting in impaired adipocyte differentiation in both mouse and human cell systems. In conclusion, PRKAR2B is the key PKA regulatory subunit involved in mouse and human adipose tissue development. The physiological increase in the expression of PRKAR2B is an essential event in adipogenesis in both mice and humans, and it might represent a possible target for future strategies for obesity treatment.
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Affiliation(s)
- Erika Peverelli
- Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community HealthUniversity of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoPad.Granelli Via F. Sforza 3520122, MilanItaly
| | - Federica Ermetici
- Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community HealthUniversity of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoPad.Granelli Via F. Sforza 3520122, MilanItaly
- Diabetology and Metabolic Disease UnitIRCCS Policlinico San DonatoSan Donato MilaneseItaly
| | - Sabrina Corbetta
- Endocrinology Unit, IRCCS Policlinico S.Donato, Department of Biomedical Sciences for HealthUniversity of MilanMilanItaly
| | - Ettore Gozzini
- Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community HealthUniversity of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoPad.Granelli Via F. Sforza 3520122, MilanItaly
| | - Laura Avagliano
- Department of Health Sciences, Unit of Human Pathology – San Paolo Hospital Medical SchoolUniversity of MilanMilanoItaly
| | - Marco A Zappa
- Surgical DepartmentOspedale Sacra Famiglia FatebenefratelliErbaItaly
| | - Gaetano Bulfamante
- Department of Health Sciences, Unit of Human Pathology – San Paolo Hospital Medical SchoolUniversity of MilanMilanoItaly
| | - Paolo Beck-Peccoz
- Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community HealthUniversity of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoPad.Granelli Via F. Sforza 3520122, MilanItaly
| | - Anna Spada
- Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community HealthUniversity of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoPad.Granelli Via F. Sforza 3520122, MilanItaly
| | - Giovanna Mantovani
- Endocrinology and Diabetology Unit, Department of Clinical Sciences and Community HealthUniversity of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoPad.Granelli Via F. Sforza 3520122, MilanItaly
- Correspondence should be addressed to G Mantovani
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139
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Mastrandrea LD. Role of sphingosine kinases and sphingosine 1-phosphate in mediating adipogenesis. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/jdm.2013.32009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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140
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Role of C/EBPβ-LAP and C/EBPβ-LIP in early adipogenic differentiation of human white adipose-derived progenitors and at later stages in immature adipocytes. Differentiation 2013; 85:20-31. [DOI: 10.1016/j.diff.2012.11.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/20/2012] [Accepted: 11/26/2012] [Indexed: 12/20/2022]
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141
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Plac8 is required for white adipocyte differentiation in vitro and cell number control in vivo. PLoS One 2012; 7:e48767. [PMID: 23155406 PMCID: PMC3498234 DOI: 10.1371/journal.pone.0048767] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 10/05/2012] [Indexed: 01/21/2023] Open
Abstract
Plac8 belongs to an evolutionary conserved family of proteins, mostly abundant in plants where they control fruit weight through regulation of cell number. In mice, Plac8 is expressed both in white and brown adipose tissues and we previously showed that Plac8−/− mice develop late-onset obesity, with abnormal brown fat differentiation and reduced thermogenic capacity. We also showed that in brown adipocytes, Plac8 is an upstream regulator of C/EBPβ expression. Here, we first assessed the role of Plac8 in white adipogenesis in vitro. We show that Plac8 is induced early after induction of 3T3-L1 adipocytes differentiation, a process that is prevented by Plac8 knockdown; similarly, embryonic fibroblasts obtained from Plac8 knockout mice failed to form adipocytes upon stimulation of differentiation. Knockdown of Plac8 in 3T3-L1 was associated with reduced expression of C/EBPβ, Krox20, and Klf4, early regulators of the white adipogenic program, and we show that Plac8 could transactivate the C/EBPβ promoter. In vivo, we show that absence of Plac8 led to increased white fat mass with enlarged adipocytes but reduced total number of adipocytes. Finally, even though Plac8−/− mice showed impaired thermogenesis due to brown fat dysfunction, this was not associated with changes in glycemia or plasma free fatty acid and triglyceride levels. Collectively, these data indicate that Plac8 is an upstream regulator of C/EBPβ required for adipogenesis in vitro. However, in vivo, Plac8 is dispensable for the differentiation of white adipocytes with preserved fat storage capacity but is required for normal fat cell number regulation.
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142
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Liu GS, Chan EC, Higuchi M, Dusting GJ, Jiang F. Redox mechanisms in regulation of adipocyte differentiation: beyond a general stress response. Cells 2012; 1:976-93. [PMID: 24710538 PMCID: PMC3901142 DOI: 10.3390/cells1040976] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 10/26/2012] [Accepted: 10/31/2012] [Indexed: 02/07/2023] Open
Abstract
In this review, we summarize advances in our understanding of redox-sensitive mechanisms that regulate adipogenesis. Current evidence indicates that reactive oxygen species may act to promote both the initiation of adipocyte lineage commitment of precursor or stem cells, and the terminal differentiation of preadipocytes to mature adipose cells. These can involve redox regulation of pathways mediated by receptor tyrosine kinases, peroxisome proliferator-activated receptor γ (PPARγ), PPARγ coactivator 1α (PGC-1α), AMP-activated protein kinase (AMPK), and CCAAT/enhancer binding protein β (C/EBPβ). However, the precise roles of ROS in adipogenesis in vivo remain controversial. More studies are needed to delineate the roles of reactive oxygen species and redox signaling mechanisms, which could be either positive or negative, in the pathogenesis of obesity and related metabolic disorders.
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Affiliation(s)
- Guei-Sheung Liu
- Centre for Eye Research Australia, University of Melbourne, Victoria 3002, Australia.
| | - Elsa C Chan
- Centre for Eye Research Australia, University of Melbourne, Victoria 3002, Australia.
| | - Masayoshi Higuchi
- Centre for Eye Research Australia, University of Melbourne, Victoria 3002, Australia.
| | - Gregory J Dusting
- Centre for Eye Research Australia, University of Melbourne, Victoria 3002, Australia.
| | - Fan Jiang
- Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan 250-012, Shandong, China.
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143
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Su H, Lau WB, Ma XL. Hypoadiponectinaemia in diabetes mellitus type 2: molecular mechanisms and clinical significance. Clin Exp Pharmacol Physiol 2012; 38:897-904. [PMID: 21916932 DOI: 10.1111/j.1440-1681.2011.05606.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. This review focuses on the regulatory mechanisms of adiponectin (APN) gene expression during physiologic conditions and both the clinical significance and underlying molecular mechanisms of hypoadiponectinaemia during pathologic conditions. 2. Adiponectin is a versatile cardiovascular protective factor. It plays an important role in regulating insulin sensitivity and energy homeostasis, with anti-inflammatory and anti-atherosclerotic properties. 3. Adiponectin gene expression is downregulated in both obesity and diabetes mellitus type 2. Hypoadiponectinaemia is an independent risk factor for coronary artery disease in type 2 diabetic patients. 4. Exogenous supplementation of recombinant APN attenuates insulin resistance, improving metabolic disorders. Therefore, APN-targeted pharmaceutical strategies increasing circulating APN levels may be therapeutic against type 2 diabetes. 5. There is great value in elucidating the regulatory mechanisms of APN gene expression during physiologic and pathologic conditions. APN biosynthesis regulation includes transcriptional expression and post-translational modification, oligomerization, and secretion. Under pathological conditions, including obesity and diabetes mellitus type 2, hypoxia, oxidative stress, and inflammation suppress APN mRNA levels and its secretion.
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Affiliation(s)
- Hui Su
- Department of Geriatrics, Xijing Hospital, Xi-an, China
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144
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Kadota Y, Yanagawa M, Nakaya T, Kawakami T, Sato M, Suzuki S. Gene expression of mesoderm-specific transcript is upregulated as preadipocytes differentiate to adipocytes in vitro. J Physiol Sci 2012; 62:403-11. [PMID: 22753118 PMCID: PMC10717349 DOI: 10.1007/s12576-012-0217-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 06/04/2012] [Indexed: 12/01/2022]
Abstract
Mesoderm-specific transcript (Mest) is a distinct gene associated with adipocyte differentiation and proliferation. The mechanisms regulating expression of the Mest gene are not established. Therefore, we investigated Mest gene expression during adipogenic differentiation in murine 3T3-L1 preadipocytes and adipose-derived stromal cells (ADCs) from C57BL/6J mouse adipose tissue. Expression of Mest mRNA increased significantly in 3T3-L1 cells during differentiation. Additionally, Mest mRNA expression levels were additively enhanced by the inhibition of DNA methylation. Expression levels of the Mest gene were also markedly elevated in differentiating ADCs in vitro. Additionally, we showed that Mest mRNA can be upregulated by increasing intracellular cAMP, and that Mest expression is suppressed by inhibition of protein kinase A (PKA). Mest expression was regulated through cAMP-dependent PKA pathways during differentiation of preadipocytes into adipocytes in vitro, supporting the critical role of Mest in proliferation and differentiation of adipocytes.
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Affiliation(s)
- Yoshito Kadota
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Yamashiro-cho, Tokushima, 770-8514, Japan.
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145
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vom Saal FS, Nagel SC, Coe BL, Angle BM, Taylor JA. The estrogenic endocrine disrupting chemical bisphenol A (BPA) and obesity. Mol Cell Endocrinol 2012; 354:74-84. [PMID: 22249005 PMCID: PMC3306519 DOI: 10.1016/j.mce.2012.01.001] [Citation(s) in RCA: 290] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/30/2011] [Accepted: 01/02/2012] [Indexed: 11/29/2022]
Abstract
There is increasing experimental and epidemiological evidence that fetal programming of genetic systems is a contributing factor in the recent increase in adult obesity and other components of metabolic syndrome. In particular, there is evidence that epigenetic changes associated with the use of manmade chemicals may interact with other factors that influence fetal and postnatal growth in contributing to the current obesity epidemic. The focus of this review is on the developmental effects of estrogenic endocrine disrupting chemicals (EDCs), and more specifically on effects of exposure to the estrogenic EDC bisphenol A (BPA), on adipocytes and their function, and the ultimate impact on adult obesity; BPA exposure also results in impaired reproductive capacity. We discuss the interaction of EDCs with other factors that impact growth during fetal and neonatal life, such as placental blood flow and nutrient transport to fetuses, and how these influence fetal growth and abnormalities in homeostatic control systems required to maintain normal body weight throughout life.
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Affiliation(s)
- Frederick S. vom Saal
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, MO, 65211 USA
| | - Susan C. Nagel
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri-Columbia, Columbia, MO, 65211 USA
| | - Benjamin L. Coe
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, MO, 65211 USA
| | - Brittany M. Angle
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, MO, 65211 USA
| | - Julia A. Taylor
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, MO, 65211 USA
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146
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Tang Z, Shi D, Jia B, Chen J, Zong C, Shen D, Zheng Q, Wang J, Tong X. Exchange protein activated by cyclic adenosine monophosphate regulates the switch between adipogenesis and osteogenesis of human mesenchymal stem cells through increasing the activation of phosphatidylinositol 3-kinase. Int J Biochem Cell Biol 2012; 44:1106-20. [PMID: 22497928 DOI: 10.1016/j.biocel.2012.03.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Revised: 03/24/2012] [Accepted: 03/26/2012] [Indexed: 11/28/2022]
Abstract
Epac, exchange protein activated by cyclic adenosine monophosphate (cAMP), could regulate the trans-differentiation between adipogenesis and osteogenesis of human mesenchymal stem cells (hMSCs). Epac activated by 8-pCPT-2'-O-Me-cAMP, a cAMP analog preferentially activating Epac, resulted in the increase of adipogenic gene expression and the decrease of osteogenic gene expression. The pro-adipogenic and anti-osteogenic effect of 8-pCPT-2'-O-Me-cAMP was attributed to that 8-pCPT-2'-O-Me-cAMP led to the activation of protein kinase B (PKB) and cAMP response element-binding protein (CREB) as well as the inhibition of Ras homolog gene family member A (RhoA), focal adhesion kinase (FAK), extracellular-signal-regulated kinase (ERK) and runt-related transcription factor 2 (Runx2) activities. Inhibition of Epac by a dominant-negative form of Epac1 resulted in the decrease of phosphatidylinositol 3-kinase (PI3K), PKB and CREB activities as well as down-regulation of peroxisome proliferator activated receptor-γ (PPARγ) expression. Inhibition of PI3K by a specific inhibitor or inhibition of Arf and Rho GAP adapter protein 3 (ARAP3, a phosphatidylinositol (PtdIns)(3,4,5)P(3) binding protein) by ARAP3 siRNA led to the recovery of RhoA and FAK activities. RhoA-V14, a constitutively active form of RhoA, could activate the MEK/ERK/Runx2 signaling. Therefore, we conclude that PI3K activated by Epac leads to the activation of PKB/CREB signaling and the up-regulation of PPARγ expression, which in turn activate the transcription of adipogenic genes; whereas osteogenesis is driven by Rho/FAK/MEK/ERK/Runx2 signaling, which can be inhibited by Epac via PI3K. These results should be helpful to provide new targets for treatment of osteoporosis and related bone-wasting diseases.
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Affiliation(s)
- Zihua Tang
- Institute of Cell and Development Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China
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147
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Abstract
Excessive caloric intake without a rise in energy expenditure promotes adipocyte hyperplasia and adiposity. The rise in adipocyte number is triggered by signaling factors that induce conversion of mesenchymal stem cells (MSCs) to preadipocytes that differentiate into adipocytes. MSCs, which are recruited from the vascular stroma of adipose tissue, provide an unlimited supply of adipocyte precursors. Members of the BMP and Wnt families are key mediators of stem cell commitment to produce preadipocytes. Following commitment, exposure of growth-arrested preadipocytes to differentiation inducers [insulin-like growth factor 1 (IGF1), glucocorticoid, and cyclic AMP (cAMP)] triggers DNA replication and reentry into the cell cycle (mitotic clonal expansion). Mitotic clonal expansion involves a transcription factor cascade, followed by the expression of adipocyte genes. Critical to these events are phosphorylations of the transcription factor CCATT enhancer-binding protein β (C/EBPβ) by MAP kinase and GSK3β to produce a conformational change that gives rise to DNA-binding activity. "Activated" C/EBPβ then triggers transcription of peroxisome proliferator-activated receptor-γ (PPARγ) and C/EBPα, which in turn coordinately activate genes whose expression produces the adipocyte phenotype.
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Affiliation(s)
- Qi Qun Tang
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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148
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Hallenborg P, Feddersen S, Francoz S, Murano I, Sundekilde U, Petersen RK, Akimov V, Olson MV, Lozano G, Cinti S, Gjertsen BT, Madsen L, Marine JC, Blagoev B, Kristiansen K. Mdm2 controls CREB-dependent transactivation and initiation of adipocyte differentiation. Cell Death Differ 2012; 19:1381-9. [PMID: 22388350 DOI: 10.1038/cdd.2012.15] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The role of the E3 ubiquitin ligase murine double minute 2 (Mdm2) in regulating the stability of the p53 tumor suppressor is well documented. By contrast, relatively little is known about p53-independent activities of Mdm2 and the role of Mdm2 in cellular differentiation. Here we report a novel role for Mdm2 in the initiation of adipocyte differentiation that is independent of its ability to regulate p53. We show that Mdm2 is required for cAMP-mediated induction of CCAAT/enhancer-binding protein δ (C/EBPδ) expression by facilitating recruitment of the cAMP regulatory element-binding protein (CREB) coactivator, CREB-regulated transcription coactivator (Crtc2)/TORC2, to the c/ebpδ promoter. Our findings reveal an unexpected role for Mdm2 in the regulation of CREB-dependent transactivation during the initiation of adipogenesis. As Mdm2 is able to promote adipogenesis in the myoblast cell line C2C12, it is conceivable that Mdm2 acts as a switch in cell fate determination.
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Affiliation(s)
- P Hallenborg
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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149
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Siersbæk R, Nielsen R, Mandrup S. Transcriptional networks and chromatin remodeling controlling adipogenesis. Trends Endocrinol Metab 2012; 23:56-64. [PMID: 22079269 DOI: 10.1016/j.tem.2011.10.001] [Citation(s) in RCA: 214] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 10/07/2011] [Accepted: 10/12/2011] [Indexed: 12/12/2022]
Abstract
Adipocyte differentiation is tightly controlled by a transcriptional cascade, which directs the extensive reprogramming of gene expression required to convert fibroblast-like precursor cells into mature lipid-laden adipocytes. Recent global analyses of transcription factor binding and chromatin remodeling have revealed 'snapshots' of this cascade and the chromatin landscape at specific time-points of differentiation. These studies demonstrate that multiple adipogenic transcription factors co-occupy hotspots characterized by an open chromatin structure and specific epigenetic modifications. Such transcription factor hotspots are likely to represent key signaling nodes which integrate multiple adipogenic signals at specific chromatin sites, thereby facilitating coordinated action on gene expression.
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Affiliation(s)
- Rasmus Siersbæk
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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150
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Berardinelli-seip congenital lipodystrophy 2/seipin is a cell-autonomous regulator of lipolysis essential for adipocyte differentiation. Mol Cell Biol 2012; 32:1099-111. [PMID: 22269949 DOI: 10.1128/mcb.06465-11] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Mutations in BSCL2 underlie human congenital generalized lipodystrophy. We inactivated Bscl2 in mice to examine the mechanisms whereby absence of Bscl2 leads to adipose tissue loss and metabolic disorders. Bscl2(-/-) mice develop severe lipodystrophy of white adipose tissue (WAT), dyslipidemia, insulin resistance, and hepatic steatosis. In vitro differentiation of both Bscl2(-/-) murine embryonic fibroblasts (MEFs) and stromal vascular cells (SVCs) reveals normal early-phase adipocyte differentiation but a striking failure in terminal differentiation due to unbridled cyclic AMP (cAMP)-dependent protein kinase A (PKA)-activated lipolysis, which leads to loss of lipid droplets and silencing of the expression of adipose tissue-specific transcription factors. Importantly, such defects in differentiation can be largely rescued by inhibitors of lipolysis but not by a gamma peroxisome proliferator-activated receptor (PPARγ) agonist. The residual epididymal WAT (EWAT) in Bscl2(-/-) mice displays enhanced lipolysis. It also assumes a "brown-like" phenotype with marked upregulation of UCP1 and other brown adipose tissue-specific markers. Together with decreased Pref1 but increased C/EBPβ levels, these changes highlight a possible increase in cAMP signaling that impairs terminal adipocyte differentiation in the EWAT of Bscl2(-/-) mice. Our study underscores the fundamental role of regulated cAMP/PKA-mediated lipolysis in adipose differentiation and identifies Bscl2 as a novel cell-autonomous determinant of activated lipolysis essential for terminal adipocyte differentiation.
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