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Taghizadeh N, Mohammadi S, yousefi Z, Golpour P, Taheri A, Maleki MH, Nourbakhsh M, Nourbakhsh M, Azar MR. Assessment of global histone acetylation in pediatric and adolescent obesity: Correlations with SIRT1 expression and metabolic-inflammatory profiles. PLoS One 2023; 18:e0293217. [PMID: 37862340 PMCID: PMC10588878 DOI: 10.1371/journal.pone.0293217] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 10/07/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Epigenetic modifications, particularly histone acetylation-deacetylation and its related enzymes, such as sirtuin 1 (SIRT1) deacetylase, may have substantial roles in the pathogenesis of obesity and its associated health issues. This study aimed to evaluate global histone acetylation status and SIRT1 gene expression in children and adolescents with obesity and their association with metabolic and anthropometric parameters. METHODS This study included 60 children and adolescents, 30 with obesity and 30 normal-weight. The evaluation consisted of the analysis of global histone acetylation levels and the expression of the SIRT1 gene in peripheral blood mononuclear cells, by specific antibody and real-time PCR, respectively. Additionally, insulin, fasting plasma glucose, lipid profile and tumor necrosis factor α (TNF-α) levels were measured. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Metabolic syndrome was determined based on the diagnostic criteria established by IDF. RESULTS Individuals with obesity, particularly those with insulin resistance, had significantly higher histone acetylation levels compared to control group. Histone acetylation was positively correlated with obesity indices, TNF-α, insulin, and HOMA-IR. Additionally, a significant decrease in SIRT1 gene expression was found among obese individuals, which was negatively correlated with the histone acetylation level. Furthermore, SIRT1 expression levels showed a negative correlation with various anthropometric and metabolic parameters. CONCLUSION Histone acetylation was enhanced in children and adolescents with obesity, potentially resulting from down-regulation of SIRT1, and could play a role in the obesity-associated metabolic abnormalities and insulin resistance. Targeting global histone acetylation modulation might be considered as an epigenetic approach for early obesity management.
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Affiliation(s)
- Nima Taghizadeh
- Metabolic Disorders Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Soha Mohammadi
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Zeynab yousefi
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Pegah Golpour
- Department of Biochemistry, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Alemeh Taheri
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hasan Maleki
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mitra Nourbakhsh
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Finetech in Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mona Nourbakhsh
- Hazrat Aliasghar Children Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Razzaghy Azar
- Metabolic Disorders Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Hazrat Aliasghar Children Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Mengeste AM, Rustan AC, Lund J. Skeletal muscle energy metabolism in obesity. Obesity (Silver Spring) 2021; 29:1582-1595. [PMID: 34464025 DOI: 10.1002/oby.23227] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 01/22/2023]
Abstract
Comparing energy metabolism in human skeletal muscle and primary skeletal muscle cells in obesity, while focusing on glucose and fatty acid metabolism, shows many common changes. Insulin-mediated glucose uptake in skeletal muscle and primary myotubes is decreased by obesity, whereas differences in basal glucose metabolism are inconsistent among studies. With respect to fatty acid metabolism, there is an increased uptake and storage of fatty acids and a reduced complete lipolysis, suggesting alterations in lipid turnover. In addition, fatty acid oxidation is decreased, probably at the level of complete oxidation, as β -oxidation may be enhanced in obesity, which indicates mitochondrial dysfunction. Metabolic changes in skeletal muscle with obesity promote metabolic inflexibility, ectopic lipid accumulation, and formation of toxic lipid intermediates. Skeletal muscle also acts as an endocrine organ, secreting myokines that participate in interorgan cross talk. This review highlights interventions and some possible targets for treatment through action on skeletal muscle energy metabolism. Effects of exercise in vivo on obesity have been compared with simulation of endurance exercise in vitro on myotubes (electrical pulse stimulation). Possible pharmaceutical targets, including signaling pathways and drug candidates that could modify lipid storage and turnover or increase mitochondrial function or cellular energy expenditure through adaptive thermogenic mechanisms, are discussed.
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Affiliation(s)
- Abel M Mengeste
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
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Ait-Aissa K, Nguyen QM, Gabani M, Kassan A, Kumar S, Choi SK, Gonzalez AA, Khataei T, Sahyoun AM, Chen C, Kassan M. MicroRNAs and obesity-induced endothelial dysfunction: key paradigms in molecular therapy. Cardiovasc Diabetol 2020; 19:136. [PMID: 32907629 PMCID: PMC7488343 DOI: 10.1186/s12933-020-01107-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/28/2020] [Indexed: 01/17/2023] Open
Abstract
The endothelium plays a pivotal role in maintaining vascular health. Obesity is a global epidemic that has seen dramatic increases in both adult and pediatric populations. Obesity perturbs the integrity of normal endothelium, leading to endothelial dysfunction which predisposes the patient to cardiovascular diseases. MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that play important roles in a variety of cellular processes such as differentiation, proliferation, apoptosis, and stress response; their alteration contributes to the development of many pathologies including obesity. Mediators of obesity-induced endothelial dysfunction include altered endothelial nitric oxide synthase (eNOS), Sirtuin 1 (SIRT1), oxidative stress, autophagy machinery and endoplasmic reticulum (ER) stress. All of these factors have been shown to be either directly or indirectly caused by gene regulatory mechanisms of miRNAs. In this review, we aim to provide a comprehensive description of the therapeutic potential of miRNAs to treat obesity-induced endothelial dysfunction. This may lead to the identification of new targets for interventions that may prevent or delay the development of obesity-related cardiovascular disease.
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Affiliation(s)
- Karima Ait-Aissa
- Cardiovascular Division, Department of Medicine, and Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
| | - Quynh My Nguyen
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, USA
| | - Mohanad Gabani
- Cardiovascular Division, Department of Medicine, and Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Adam Kassan
- Department of Pharmaceutical Sciences, School of Pharmacy, West Coast University, Los Angeles, USA
| | - Santosh Kumar
- Cardiovascular Division, Department of Medicine, and Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Soo-Kyoung Choi
- Department of Physiology, College of Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Alexis A Gonzalez
- Instituto de Química, Pontificia, Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Tahsin Khataei
- Cardiovascular Division, Department of Medicine, and Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Amal M Sahyoun
- Department of Food Science and Agriculture Chemistry, McGill University, Montreal, QC, Canada
| | - Cheng Chen
- Department of emergency and Critical Care, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Modar Kassan
- Cardiovascular Division, Department of Medicine, and Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
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Sharma M, Molehin D, Castro-Piedras I, Martinez EG, Pruitt K. Acetylation of conserved DVL-1 lysines regulates its nuclear translocation and binding to gene promoters in triple-negative breast cancer. Sci Rep 2019; 9:16257. [PMID: 31700102 PMCID: PMC6838061 DOI: 10.1038/s41598-019-52723-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 10/22/2019] [Indexed: 12/15/2022] Open
Abstract
Dishevelled (DVL) proteins are central mediators of the Wnt signalling pathway and are versatile regulators of several cellular processes, yet little is known about their post-translational regulation. Acetylation is a reversible post-translational modification (PTM) which regulates the function of several non-histone proteins involved in tumorigenesis. Since we previously demonstrated that lysine deacetylase, SIRT-1, regulates DVL protein levels and its function, we reasoned that DVL could potentially be a substrate for SIRT-1 mediated deacetylation. To further examine the potential role of multiple families of lysine deacetylases in the post-translational regulation of DVL, we screened for novel acetylation sites using liquid chromatography mass-spectrometry (LC-MS/MS) analysis. Herein, we report 12 DVL-1 lysine residues that show differential acetylation in response to changes in oxygen tension and deacetylase inhibition in triple-negative breast cancer (TNBC). PTMs are well documented to influence protein activity, and cellular localization. We also identify that acetylation of two key lysine residues, K69 and K285, present on the DIX and PDZ domains respectively, promote nuclear over cytoplasmic localization of DVL-1, and influences its promoter binding and regulation of genes implicated in cancer. Collectively, these findings for the first time, uncover acetylation as a novel layer of regulation of DVL-1 proteins.
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Affiliation(s)
- Monica Sharma
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Deborah Molehin
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Isabel Castro-Piedras
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Edgar G Martinez
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Kevin Pruitt
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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Fernandes-Cardoso A, Santos-Furtado M, Grindler J, Ferreira LA, Andrade JL, Santo MA. Epicardial fat thickness correlates with P-wave duration, left atrial size and decreased left ventricular systolic function in morbid obesity. Nutr Metab Cardiovasc Dis 2017; 27:731-738. [PMID: 28739186 DOI: 10.1016/j.numecd.2017.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/20/2017] [Accepted: 05/22/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND AIM Epicardial fat (EF) is increased in obesity and has important interactions with atrial and ventricular myocardium. Most of the evidence in this scenario can be confused by the presence of comorbidities such as hypertension, diabetes and dyslipidemia, which are very common in this population. The influence of EF on atrial remodeling and cardiac function demands further investigation on morbidly obese without these comorbidities. METHODS AND RESULTS We prospectively recruited 20 metabolically healthy morbidly obese and 20 normo-weights controls. The maximum P-wave duration (PWD) was analyzed by 12-lead electrocardiogram. Left atrial diameter (LAD), left ventricular ejection fraction (LVEF) and EF thickness (EFT) were evaluated by two-dimensional echocardiography. The mean of maximum PWD and LAD were significantly larger in the obese group as compared to the control group: 109.55 ± 11.52 ms × 89.38 ± 11.19 ms and 36.12 ± 3.46 mm × 31.45 ± 2.64 mm, (p < 0.0001). The mean LVEF was lower in the obese group: 63.15 ± 4.25% × 66.17 ± 3.37% (p < 0.017). The mean EFT was higher in the obese group: 7.72 ± 1.60 mm × 3.10 ± 0.85 mm (p < 0.0001). A positive correlation was found between EFT and PWD (r = 0.70; p = 0.001) and LAD (r = 0.667; p = 0.001). An inverse correlation was found between EFT and LVEF (r = -0.523; p = 0.001). In a multiple multivariate regression analysis the EFT remains correlated with LAD and LVEF. CONCLUSIONS In a select group of morbidly obese, the excess of EF had a significant impact on atrial remodeling and cardiac function.
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MESH Headings
- Adipose Tissue/diagnostic imaging
- Adipose Tissue/physiopathology
- Adiposity
- Adult
- Arrhythmias, Cardiac/diagnosis
- Arrhythmias, Cardiac/etiology
- Arrhythmias, Cardiac/physiopathology
- Atrial Function, Left
- Atrial Remodeling
- Cross-Sectional Studies
- Echocardiography
- Electrocardiography
- Female
- Heart Atria/diagnostic imaging
- Heart Atria/physiopathology
- Humans
- Linear Models
- Male
- Middle Aged
- Multivariate Analysis
- Obesity, Metabolically Benign/complications
- Obesity, Metabolically Benign/diagnosis
- Obesity, Metabolically Benign/physiopathology
- Obesity, Morbid/complications
- Obesity, Morbid/diagnosis
- Obesity, Morbid/physiopathology
- Pericardium/diagnostic imaging
- Pericardium/physiopathology
- Predictive Value of Tests
- Prospective Studies
- Risk Factors
- Stroke Volume
- Systole
- Ventricular Dysfunction, Left/diagnosis
- Ventricular Dysfunction, Left/etiology
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
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Affiliation(s)
- A Fernandes-Cardoso
- Electrocardiology Service, Medical Clinic Department, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), Brazil.
| | - M Santos-Furtado
- Echocardiography Laboratory, Radiology Institute (InRad), HCFMUSP, Brazil
| | - J Grindler
- Electrocardiology Service, Medical Clinic Department, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), Brazil
| | - L A Ferreira
- Institute of Mathematics and Statistics, Department of Statistics, IMEUSP, Brazil
| | - J L Andrade
- Echocardiography Laboratory, Radiology Institute (InRad), HCFMUSP, Brazil
| | - M A Santo
- Bariatric Surgery Unit, Gastroenterology Department, HCFMUSP, Brazil
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Hosick PA, Weeks MF, Hankins MW, Moore KH, Stec DE. Sex-Dependent Effects of HO-1 Deletion from Adipocytes in Mice. Int J Mol Sci 2017; 18:ijms18030611. [PMID: 28287466 PMCID: PMC5372627 DOI: 10.3390/ijms18030611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 01/01/2023] Open
Abstract
Induction of heme oxygenase-1 (HO-1) has been demonstrated to decrease body weight and improve insulin sensitivity in several models of obesity in rodents. To further study the role of HO-1 in adipose tissue, we created an adipose-specific HO-1 knockout mouse model. Male and female mice were fed either a control or a high-fat diet for 30 weeks. Body weights were measured weekly and body composition, fasting blood glucose and insulin levels were determined every six weeks. Adipocyte-specific knockout of HO-1 had no significant effect on body weight in mice fed a high-fat diet but increased body weight in female mice fed a normal-fat diet. Although body weights were not different in females fed a high fat diet, loss of HO-1 in adipocytes resulted in significant alterations in body composition. Adipose-specific HO-1 knockout resulted in increased fasting hyperglycemia and insulinemia in female but not male mice on both diets. Adipose-specific knockout of HO-1 resulted in a significant loss of HO activity and a decrease in the protein levels of adiponectin in adipose tissue. These results demonstrate that loss of HO-1 in adipocytes has greater effects on body fat and fasting hyperglycemia in a sex-dependent fashion and that expression of HO-1 in adipose tissue may have a greater protective role in females as compared to males.
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Affiliation(s)
- Peter A Hosick
- Department of Physiology & Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA.
- Department of Exercise Science and Physical Education, Montclair State University, Montclair, NJ 07043, USA.
| | - Mary Frances Weeks
- Department of Physiology & Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA.
| | - Michael W Hankins
- Department of Physiology & Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA.
| | - Kyle H Moore
- Department of Physiology & Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA.
| | - David E Stec
- Department of Physiology & Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA.
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AAV-mediated Sirt1 overexpression in skeletal muscle activates oxidative capacity but does not prevent insulin resistance. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 5:16072. [PMID: 27909699 PMCID: PMC5111573 DOI: 10.1038/mtm.2016.72] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/15/2016] [Accepted: 09/29/2016] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes is characterized by triglyceride accumulation and reduced lipid oxidation capacity in skeletal muscle. SIRT1 is a key protein in the regulation of lipid oxidation and its expression is reduced in the skeletal muscle of insulin resistant mice. In this tissue, Sirt1 up-regulates the expression of genes involved in oxidative metabolism and improves mitochondrial function mainly through PPARGC1 deacetylation. Here we examined whether Sirt1 overexpression mediated by adeno-associated viral vectors of serotype 1 (AAV1) specifically in skeletal muscle can counteract the development of insulin resistance induced by a high fat diet in mice. AAV1-Sirt1-treated mice showed up-regulated expression of key genes related to β-oxidation together with increased levels of phosphorylated AMP protein kinase. Moreover, SIRT1 overexpression in skeletal muscle also increased basal phosphorylated levels of AKT. However, AAV1-Sirt1 treatment was not enough to prevent high fat diet-induced obesity and insulin resistance. Although Sirt1 gene transfer to skeletal muscle induced changes at the muscular level related with lipid and glucose homeostasis, our data indicate that overexpression of SIRT1 in skeletal muscle is not enough to improve whole-body insulin resistance and that suggests that SIRT1 has to be increased in other metabolic tissues to prevent insulin resistance.
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8
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Mariani S, Costantini D, Lubrano C, Basciani S, Caldaroni C, Barbaro G, Poggiogalle E, Donini LM, Lenzi A, Gnessi L. Circulating SIRT1 inversely correlates with epicardial fat thickness in patients with obesity. Nutr Metab Cardiovasc Dis 2016; 26:1033-1038. [PMID: 27378396 DOI: 10.1016/j.numecd.2016.06.001] [Citation(s) in RCA: 15] [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] [Received: 02/19/2016] [Revised: 05/25/2016] [Accepted: 06/08/2016] [Indexed: 01/03/2023]
Abstract
BACKGROUND AND AIM Obesity is increasing worldwide and is related to undesirable cardiovascular outcomes. Epicardial fat (EF), the heart visceral fat depot, increases with obesity and correlates with cardiovascular risk. SIRT1, an enzyme regulating metabolic circuits linked with obesity, has a cardioprotective effect and is a predictor of cardiovascular events. We aimed to assess the relationship of EF thickness (EFT) with circulating SIRT1 in patients with obesity. METHODS AND RESULTS Sixty-two patients affected by obesity and 23 lean controls were studied. Plasma SIRT1 concentration was determined by enzyme-linked immunosorbent assay (ELISA). EFT was measured by echocardiography. Body mass index (BMI), waist circumference, heart rate (HR), blood pressure, and laboratory findings (fasting glucose, insulin, HbA1c, cholesterol, and triglycerides) were assessed. SIRT1 was significantly lower (P = 0.002) and EFT was higher (P < 0.0001) in patients with obesity compared with lean controls. SIRT1 showed a negative correlation with EFT and HR in the obesity group (ρ = -0.350, P = 0.005; ρ = -0.303, P = 0.008, respectively). After adjustment for obesity-correlated variables, multiple linear regression analysis showed that EFT remained the best correlate of SIRT1 (β = -0.352, P = 0.016). CONCLUSIONS Circulating SIRT1 correlates with the visceral fat content of the heart. Serum SIRT1 levels might provide additional information for risk assessment of coronary artery disease in patients with obesity.
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Affiliation(s)
- S Mariani
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy.
| | - D Costantini
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - C Lubrano
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - S Basciani
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - C Caldaroni
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - G Barbaro
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - E Poggiogalle
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - L M Donini
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - A Lenzi
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
| | - L Gnessi
- Department of Experimental Medicine, Section of Medical Physiopathology, Food Science and Endocrinology, "Sapienza" University of Rome, 00161 Rome, Italy
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Pruitt K. Molecular and Cellular Changes During Cancer Progression Resulting From Genetic and Epigenetic Alterations. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 144:3-47. [PMID: 27865461 DOI: 10.1016/bs.pmbts.2016.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tumorigenesis is a complex process that involves a persistent dismantling of cellular safeguards and checkpoints. These molecular and cellular changes that accumulate over months or decades lead to a change in the fundamental identity of a cell as it transitions from normal to malignant. In this chapter, we will examine some of the molecular changes in the evolving relationship between the genome and epigenome and highlight some of the key changes that occur as normal cells progress to tumor cells. For many years tumorigenesis was almost exclusively attributed to mutations in protein-coding genes. This notion that mutations in protein-coding genes were a fundamental driver of tumorigenesis enabled the development of several novel therapeutics that targeted the mutant protein or overactive pathway responsible for driving a significant portion of the tumor growth. However, because many therapeutic challenges remained in the face of these advances, it was clear that other pieces to the puzzle had yet to be discovered. Advances in molecular and genomics techniques continued and the study of epigenetics began to expand and helped reshape the view that drivers of tumorigenesis extended beyond mutations in protein-coding genes. Studies in the field of epigenetics began to identify aberrant epigenetic marks which created altered chromatin structures and enabled protein expression in tissues that defied rules governing tissue-specificity. Not only were epigenetic alterations found to enable overexpression of proto-oncogenes, they also led to the silencing of tumor suppressor genes. With these discoveries, it became clear that tumor growth could be stimulated by much more than mutations in protein-coding genes. In fact, it became increasingly clear that much of the human genome, while transcribed, did not lead to proteins. This discovery further led to studies that began to uncover the role of noncoding RNAs in regulating chromatin structure, gene transcription, and tumor biology. In this chapter, some of the key alterations in the genome and epigenome will be explored, and some of the cancer therapies that were developed as a result of these discoveries will be discussed.
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Affiliation(s)
- K Pruitt
- Texas Tech University Health Sciences Center, Lubbock, TX, United States.
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10
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Role of nutraceutical SIRT1 modulators in AMPK and mTOR pathway: Evidence of a synergistic effect. Nutrition 2016; 34:82-96. [PMID: 28063518 DOI: 10.1016/j.nut.2016.09.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 08/04/2016] [Accepted: 09/23/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the effect of different natural substances on SIRT1 expression and on AMPK and mTOR phosphorylation. Moreover, we investigated the presence of a synergistic effect between the substances. METHODS Human cervical carcinoma cells were seeded in 12-well plates, then incubated with the nine tested substances (resveratrol, quercetin, berberine, catechin, tyrosol, ferulic acid, niclosamide, curcumin, and malvidin) at different concentrations and left in incubation for 3, 6, and 24 h. The targeting proteins' expression and phosphorylation were evaluated by immunoblotting, and cytotoxicity tests were performed by CellTiter-Blue Cell Viability Assay. RESULTS No statistically significant decrease (P > 0.05) in the number of viable cells was found. The expression of SIRT1 was significantly increased in all experimental groups compared with the control group (P < 0.001). Instead, the simultaneous administration involved a significant and synergistic increase in the expression of SIRT1 for some but not all of the tested compounds. Finally, the individual administration of berberine, quercetin, ferulic acid, and tyrosol resulted in a statistically significant increase in AMPK activation and mTOR inhibition, whereas their associated administration did not reveal a synergistic effect. CONCLUSIONS Our results provide evidence that all compounds have the potential to stimulate SIRT1 and sustain the stimulating action of resveratrol on SIRT1, already widely reported in the literature. In this regard, we confirm the interaction of these substances also with the pathway of AMPK and mTOR, in support of the studies that highlight the importance of SIRT1/AMPK and mTOR pathway in many diseases.
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11
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Abstract
Sirtuins are NAD(+)-dependent enzymes universally present in all organisms, where they play central roles in regulating numerous biological processes. Although early studies showed that sirtuins deacetylated lysines in a reaction that consumes NAD(+), more recent studies have revealed that these enzymes can remove a variety of acyl-lysine modifications. The specificities for varied acyl modifications may thus underlie the distinct roles of the different sirtuins within a given organism. This review summarizes the structure, chemistry, and substrate specificity of sirtuins with a focus on how different sirtuins recognize distinct substrates and thus carry out specific functions.
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Affiliation(s)
- Poonam Bheda
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France.,Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Hui Jing
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14850
| | - Cynthia Wolberger
- Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185;
| | - Hening Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14850.,Howard Hughes Medical Institute, Cornell University, Ithaca, New York 14850;
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Al-Wahab Z, Tebbe C, Chhina J, Dar SA, Morris RT, Ali-Fehmi R, Giri S, Munkarah AR, Rattan R. Dietary energy balance modulates ovarian cancer progression and metastasis. Oncotarget 2015; 5:6063-75. [PMID: 25026276 PMCID: PMC4171613 DOI: 10.18632/oncotarget.2168] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A high energy balance, or caloric excess, accounts as a tumor promoting factor, while a negative energy balance via caloric restriction, has been shown to delay cancer progression. The effect of energy balance on ovarian cancer progression was investigated in an isogeneic immunocompetent mouse model of epithelial ovarian cancer kept on a regimen of regular diet, high energy diet (HED) and calorie restricted diet (CRD), prior to inoculating the animals intraperitoneally with the mouse ovarian surface epithelial ID8 cancer cells. Tumor evaluation revealed that mice group on HED displayed the most extensive tumor formation with the highest tumor score at all organ sites (diaphragm, peritoneum, bowel, liver, kidney, spleen), accompanied with increased levels of insulin, leptin, insulin growth factor-1 (IGF-1), monocyte chemoattractant protein-1 (MCP-1), VEGF and interleukin 6 (IL-6). On the other hand, the mice group on CRD exhibited the least tumor burden associated with a significant reduction in levels of insulin, IGF-1, leptin, MCP-1, VEGF and IL-6. Immunohistochemistry analysis of tumors from HED mice showed higher activation of Akt and mTOR with decreased adenosine monophosphate activated kinase (AMPK) and SIRT1 activation, while tumors from the CRD group exhibited the reverse profile. In conclusion, ovarian cancer growth and metastasis occurred more aggressively under HED conditions and was significantly curtailed under CRD. The suggested mechanism involves modulated secretion of growth factors, cytokines and altered regulation of AMPK and SIRT1 that converges on mTOR inhibition. While the role of a high energy state in ovarian cancer has not been confirnmed in the literature, the current findings support investigating the potential impact of diet modulation as adjunct to other anticancer therapies and as possible individualized treatment strategy of epithelial ovarian cancer.
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Affiliation(s)
- Zaid Al-Wahab
- Division of Gynecology Oncology, Wayne State University, Detroit, MI
| | - Calvin Tebbe
- Department of Women's Health, Obstetrics and Gynecology, Wayne State University, Detroit, MI
| | - Jasdeep Chhina
- Department of Women's Health, Obstetrics and Gynecology, Wayne State University, Detroit, MI
| | - Sajad A Dar
- Department of Women's Health, Obstetrics and Gynecology, Wayne State University, Detroit, MI
| | - Robert T Morris
- Division of Gynecology Oncology, Wayne State University, Detroit, MI
| | - Rouba Ali-Fehmi
- Department of Pathology, Karmanos Cancer Institute, Wayne State Univeristy, Detroit, MI
| | | | - Adnan R Munkarah
- Department of Women's Health, Obstetrics and Gynecology, Wayne State University, Detroit, MI
| | - Ramandeep Rattan
- Department of Women's Health, Obstetrics and Gynecology, Wayne State University, Detroit, MI
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Diverse roles of SIRT1 in cancer biology and lipid metabolism. Int J Mol Sci 2015; 16:950-65. [PMID: 25569080 PMCID: PMC4307284 DOI: 10.3390/ijms16010950] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 12/24/2014] [Indexed: 12/18/2022] Open
Abstract
SIRT1, an NAD+-dependent deacetylase, has been described in the literature as a major player in the regulation of cellular stress responses. Its expression has been shown to be altered in cancer cells, and it targets both histone and non-histone proteins for deacetylation and thereby alters metabolic programs in response to diverse physiological stress. Interestingly, many of the metabolic pathways that are influenced by SIRT1 are also altered in tumor development. Not only does SIRT1 have the potential to regulate oncogenic factors, it also orchestrates many aspects of metabolism and lipid regulation and recent reports are beginning to connect these areas. SIRT1 influences pathways that provide an alternative means of deriving energy (such as fatty acid oxidation and gluconeogenesis) when a cell encounters nutritive stress, and can therefore lead to altered lipid metabolism in various pathophysiological contexts. This review helps to show the various connections between SIRT1 and major pathways in cellular metabolism and the consequence of SIRT1 deregulation on carcinogenesis and lipid metabolism.
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Theoretical approaches to identify the potent scaffold for human sirtuin1 activator: Bayesian modeling and density functional theory. Med Chem Res 2014. [DOI: 10.1007/s00044-014-0983-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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SIRT1 expression is associated with the chemotherapy response and prognosis of patients with advanced NSCLC. PLoS One 2013; 8:e79162. [PMID: 24223900 PMCID: PMC3818418 DOI: 10.1371/journal.pone.0079162] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/17/2013] [Indexed: 12/31/2022] Open
Abstract
Aim The role of Sirtuin 1 (SIRT 1) in carcinogenesis is controversial. This study was to explore the association between the SIRT1 expression and the clinical characteristics, the responsiveness to chemotherapy and prognosis in Non-small cell lung cancer (NSCLC). Methods We enrolled 295 patients with inoperable advanced stage of NSCLC, namely, stage III (A+B) and IV NSCLC. All patients had received platinum-based chemotherapy after diagnosis and the chemotherapy response were evaluated. All patients were followed up for overall survival (OS) and progression free survival (PFS). Invitro, H292 cells were tranfected with SIRT1 small interfering RNA (siRNA). The cell biological behaviors and chemosensitivity to cisplatin treatment were studied. The invivo tumorgenesis and metastasis assays were performed in nude mice. Results We found that the SIRT1 expressions were significantly associated with the tumor stage, tumor size and differentiation status. Patients with high SIRT 1 expressions had a significantly higher chance to be resistant to chemotherapy than those with low SIRT 1 expression. Patients with high expression of SIRT1 had significantly shorter OS and DFS than those with low expression. Cox analyses confirmed that the SIRT 1 expression was a strong predictor for a poor OS and PFS in NSCLC patients underwent Platinum-based chemotherapy. Invitro studies revealed that the reduced expression SIRT 1 by siRNA technique significantly inhibited cell proliferation, migration and invasion. More importantly, SIRT1 si-RNA significantly enhanced the chemosensitivity of H292 cells to cisplatin treatment. The invivo tumorgenesis and metastasis assays showed that SIRT1 knockdown dramatically reduced the tumor volume and the metastatic ability in nude mice. Conclusion Collectively, our data suggest that the SIRT1 expression may be a molecular marker associated with the NSLCLC clinical features, treatment responsiveness and prognosis of advanced NSCLC.
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Li M, Sun X, Hua L, Lai X, Lan X, Lei C, Zhang C, Qi X, Chen H. SIRT1 gene polymorphisms are associated with growth traits in Nanyang cattle. Mol Cell Probes 2013; 27:215-20. [PMID: 23871946 DOI: 10.1016/j.mcp.2013.07.002] [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: 05/07/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 11/25/2022]
Abstract
Growth is under complex genetic control and uncovering the molecular mechanisms how the genes and polymorphisms affect economic growth traits, are important for successful marker-assisted selection and more efficient management strategies in commercial cattle populations. SIRT1 is a NAD(+)-dependent deacetylase that belongs to the class III histone deacetylases. It plays an important role in numerous fundamental cellular processes including gene silencing, DNA repair, and metabolic regulation. In addition, SIRT1 acts as an inhibitor of adipogenesis and has been associated with body weight regulation. The objective of the present study was to identify single nucleotide polymorphisms (SNPs) of bovine SIRT1 using 1255 animals representing the five main Chinese breeds and to determine if these SNPs are associated with economically important traits in Nanyang cattle. The approach consisted of resequencing SIRT1 using a panel of DNA from unrelated animals of five different breeds and the process revealed five novel SNPs. SNPs g.17324T>C and g.17491G>A exhibited a high degree of linkage disequilibrium in all tested breeds. Seven major haplotypes accounting for 91.2% of the alleles were observed and the haplotype 'GCCGA' was the most common haplotype in NY, QC, LX and JX breeds. An association analysis was performed between the five SNPs and six performance traits. SNP g.-274C>G was demonstrated to have a strong effect on 24-months-old body weight and g.17379A>G polymorphism was related to 6 and 12-months-old body weight in NY population, although these effects did not remained significant after the Bonferroni correction. Our results provide evidence that polymorphisms in SIRT1 are associated with growth efficiency traits, and may be used for marker-assisted selection and management in feedlot cattle.
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Affiliation(s)
- Mingxun Li
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
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Calorie restriction and cancer prevention: a mechanistic perspective. Cancer Metab 2013; 1:10. [PMID: 24280167 PMCID: PMC4178215 DOI: 10.1186/2049-3002-1-10] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 01/11/2013] [Indexed: 12/18/2022] Open
Abstract
Calorie restriction (CR) is one of the most potent broadly acting dietary interventions for inducing weight loss and for inhibiting cancer in experimental models. Translation of the mechanistic lessons learned from research on CR to cancer prevention strategies in human beings is important given the high prevalence of excess energy intake, obesity, and metabolic syndrome in many parts of the world and the established links between obesity-associated metabolic perturbations and increased risk or progression of many types of cancer. This review synthesizes findings on the biological mechanisms underlying many of the anticancer effects of CR, with emphasis on the impact of CR on growth factor signaling pathways, inflammation, cellular and systemic energy homeostasis pathways, vascular perturbations, and the tumor microenvironment. These CR-responsive pathways and processes represent targets for translating CR research into effective cancer prevention strategies in human beings.
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Sirt1 attenuates camptothecin-induced apoptosis through caspase-3 pathway in porcine preadipocytes. Exp Cell Res 2013; 319:670-83. [DOI: 10.1016/j.yexcr.2012.12.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 12/07/2012] [Accepted: 12/31/2012] [Indexed: 11/22/2022]
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Lee H, Chu SH, Park JY, Park HK, Im JA, Lee JW. Visceral adiposity is associated with SIRT1 expression in peripheral blood mononuclear cells: a pilot study. Endocr J 2013; 60:1269-73. [PMID: 23933590 DOI: 10.1507/endocrj.ej13-0207] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Sirtuin1 (SIRT1) is activated during calorie restriction and appears to be related to energy balance through glucose or lipid metabolism and insulin signaling. These findings suggest that SIRT1 may play a role in the pathophysiology of visceral obesity. Therefore, we investigated the relationship between SIRT1 gene expression in circulating peripheral blood mononuclear cells (PBMCs) and abdominal visceral adiposity as measured by computed tomography. We recruited 43 men and women without history of diabetes or cardiovascular disease Biomarkers of metabolic disease and body composition by computed tomography were assessed. SIRT1 gene expression was determined using isolated PBMCs. SIRT1 expression levels negatively correlated with body mass index, waist circumference, abdominal visceral fat area, and homeostasis model of assessment of insulin resistance (HOMA-IR) and positively correlated with adiponectin levels. Results of step-wise multiple regression analysis revealed that abdominal visceral fat area and HOMA-IR were independently associated with SIRT1 expression. The significant association between abdominal visceral fat accumulation and SIRT1 gene expression in PBMCs suggests that SIRT1 may be a new therapeutic target for the prevention of disease related to obesity, especially visceral obesity.
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Affiliation(s)
- Hyangkyu Lee
- Department of Clinical Nursing Science, Yonsei University College of Nursing, Nursing Policy and Research Institute, Biobehavioral Research Center, Seoul 120-752, Korea
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Gul S, Gribbon P. Exemplification of the challenges associated with utilising fluorescence intensity based assays in discovery. Expert Opin Drug Discov 2012; 5:681-90. [PMID: 22823207 DOI: 10.1517/17460441.2010.495748] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Despite the advances in the understanding of biological processes, significant challenges still face those engaged in small molecule drug discovery. To complicate matters further, researchers are often overwhelmed with a range of off-the-shelf as well as bespoke assay formats to choose from when initiating a drug discovery programme. Although fluorescence intensity based assays have traditionally been adopted in drug discovery programmes for a wide range of target classes, it is essential to fully validate the chosen readouts to confirm that they accurately reflect the underlying biological mechanism under investigation. AREAS COVERED IN THIS REVIEW This review exemplifies the challenges that are often encountered with fluorescence intensity based assays and particular attention is paid to compound interference, the protease, deacetylating enzyme and kinase enzyme target classes. WHAT THE READER WILL GAIN Designing a critical path in early stage drug discovery, which combines several diverse and minimally overlapping readout modes, will maximise the chance that compound activities will translate between the primary assay (utilised in the initial screening campaign) and secondary assay (utilised to evaluate the confirmed hits identified in the primary assay, usually a cell based assay) formats in a meaningful way. However, this is not always the case as is amply demonstrated across both academia and the pharmaceutical industry. Paying insufficient attention to these points can lead to the early termination of drug discovery programmes, not for want of resources or confidence in the rationale underlying the target, but instead because decision making has been driven by assay data originating from a different biological mechanism than the one under investigation. TAKE HOME MESSAGE Although fluorescence intensity based assays are likely to remain popular for many target classes in drug discovery, in particular in small molecule screening campaigns, it is essential that at the outset they are sufficiently well validated so that compounds are likely to exhibit profiles that are confirmed in subsequent assays.
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Affiliation(s)
- Sheraz Gul
- European ScreeningPort GmbH, Schnackenburgallee 114, 22525 Hamburg, Germany
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Sakkiah S, Chandrasekaran M, Lee Y, Kim S, Lee KW. Molecular modeling study for conformational changes of Sirtuin 2 due to substrate and inhibitor binding. J Biomol Struct Dyn 2012; 30:235-54. [PMID: 22694102 DOI: 10.1080/07391102.2012.680026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Sirtuin is a member of NAD(+)-dependent deacetylase family. The structural details of Sirtuin 2 (SIRT2) complex will be very useful to discover the drug which might have beneficial effects on various diseases like cancer, diabetes, etc. Unfortunately, SIRT2 complex structure is not available yet, hence molecular docking was carried out to dock the substrate (NAD(+) and acetylated lysine) and inhibitor (sirtinol) in the NAD(+) binding site. The suitable binding orientation of substrate and inhibitor in the SIRT2 active site was selected and subjected to 5 ns molecular dynamics simulations to adjust the binding orientation of inhibitor and substrate as well as to identify the conformational changes in the active site. The result provides an insight about 3D SIRT2 structural details as well as the importance of F96 in deacetylation function. In addition, our simulations revealed the displacement of F96 upon substrate and inhibitor binding, inducing an extended conformation of loop3 and changing its interactions with the rest of SIRT2. We believe that our study could be helpful to gain a structural insight of SIRT2 and to design the receptor-based inhibitors.
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Affiliation(s)
- Sugunadevi Sakkiah
- Division of Applied Life Science (BK21 Program), Systems and Synthetic Agrobiotech Center (SSAAC), Gyeongsang National University (GNU), Gazha-dong, Jinju, Republic of Korea
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Palmer NO, Fullston T, Mitchell M, Setchell BP, Lane M. SIRT6 in mouse spermatogenesis is modulated by diet-induced obesity. Reprod Fertil Dev 2012; 23:929-39. [PMID: 21871212 DOI: 10.1071/rd10326] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 04/15/2011] [Indexed: 12/16/2022] Open
Abstract
Male obesity is associated with reduced sperm function and increased incidence of sperm DNA damage; however, the underlying molecular mechanisms have not yet been identified. Mammalian SIRT6 protein is involved in caloric-dependant DNA damage repair in other tissue types, yet a possible role for SIRT6 in male obesity and subfertility has not been investigated previously. To assess SIRT6 levels and activity in the testes, male mice (n=12 per diet) were fed either a control diet (CD; 6% fat) or a high-fat diet (HFD; 21% fat) for 16 weeks before the collection of testes and spermatozoa. SIRT6 protein was localised to the nucleus of transitional spermatids and the acrosome of mature spermatozoa, with levels significantly decreased in HFD-fed male mice (P<0.05). This decrease in SIRT6 protein was associated with transitional spermatids having increased levels of acetylated H3K9 in the nucleus (P<0.01) and increased DNA damage (P<0.001). We propose a role for SIRT6 in spermiogenesis and potentially protamination processes, which are known to be compromised by male obesity.
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Affiliation(s)
- Nicole O Palmer
- Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, SA 5005, Australia
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Abstract
The function of the human proteome is defined by the proteostasis network (PN) (Science 2008;319:916; Science 2010;329:766), a biological system that generates, protects, and, where necessary, degrades a protein to optimize the cell, tissue, and organismal response to diet, stress, and aging. Numerous human diseases result from the failure of proteins to fold properly in response to mutation, disrupting the proteome. In the case of the exocytic pathway, this includes proteostasis components that direct folding, and export of proteins from the endoplasmic reticulum (ER). Included here are serpin deficiencies, a class of related diseases that result in a significant reduction of secretion of serine proteinase inhibitors from the liver into serum. In response to misfolding, variants of the serine protease α(1)-antitrypsin (α1AT) fail to exit the ER and are targeted for either ER-associated degradation or autophagic pathways. The challenge for developing α1AT deficiency therapeutics is to understand the PN pathways involved in folding and export. Herein, we review the role of the PN in managing the protein fold and function during synthesis in the ER and trafficking to the cell surface or extracellular space. We highlight the role of the proteostasis boundary to define the operation of the proteome (Annu Rev Biochem 2009;78:959). We discuss how manipulation of folding energetics or the PN by pharmacological intervention could provide multiple routes for restoration of variant α1AT function to the benefit of human health.
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Hursting SD, Berger NA. Energy balance, host-related factors, and cancer progression. J Clin Oncol 2010; 28:4058-65. [PMID: 20697088 DOI: 10.1200/jco.2010.27.9935] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Obesity is associated with an increased risk and worsened prognosis for many types of cancer, but the mechanisms underlying the obesity-cancer progression link are poorly understood. Several energy balance-related host factors are known to influence tumor progression and/or treatment responsiveness after cancer develops, and these have been implicated as key contributors to the complex effects of obesity on cancer outcome. These host factors include leptin, adiponectin, steroid hormones, reactive oxygen species associated with inflammation, insulin, insulin-like growth factor-1, and sirtuins. Each of these host factors is considered in this article in the context of energy balance and cancer progression. In addition, future research directions in this field are discussed, including the importance of study designs addressing energy balance across the life course, the development and application of highly relevant animal models, potential roles of cancer stem cells in the response to energy balance modulation, and emerging pharmacologic approaches that target energy balance-related pathways.
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Affiliation(s)
- Stephen D Hursting
- The University of Texas, 1 University Station A2700, Painter Hall, Room 5.32, Austin, TX 78712, USA
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Chen YR, Fang SR, Fu YC, Zhou XH, Xu MY, Xu WC. Calorie restriction on insulin resistance and expression of SIRT1 and SIRT4 in rats. Biochem Cell Biol 2010; 88:715-22. [PMID: 20651844 DOI: 10.1139/o10-010] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The sirtuin proteins are nicotinamide adenine dinucleotide dependent deacetylases and adenosine diphosphate (ADP)-ribosyl transferases associated with metabolic balance and lifespan extension. Sirtuin 1 (SIRT1) and sirtuin 4 (SIRT4) have been reported to regulate insulin secretion, but their association with the development of insulin resistance and nonalcoholic fatty liver disease remain undefined. The aim of this study was to determine the expression of SIRT1 and SIRT4 in the liver and pancreas of rats fed with different diets and analyze the association of these proteins with insulin resistance and nonalcoholic fatty liver disease. Male Sprague-Dawley rats were randomly divided into the following 4 diet treatment groups: normal control (NC), calorie restriction (CR), high-fat (HFa), and high-fructose (HFr), and these groups were maintained for 12 weeks. Blood biochemical analysis and histopathology indicated that HFa and HFr groups were insulin resistant and developed nonalcoholic fatty livers. SIRT1 was present in the nucleus and cytoplasm of the pancreatic beta-cells, while SIRT4 was located in the cytoplasm. Treatment with the CR diet increased the expression of SIRT1 in both the pancreas and liver, while treatment with the HFa and HFr diets caused a decrease. SIRT4 was upregulated in the liver of rats treated with the HFa diet, but did not change with the CR diet treatment. These data suggest that SIRT1 and SIRT4 were both involved in the development of insulin resistance and nonalcoholic fatty liver disease.
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Affiliation(s)
- Yong-Ru Chen
- Department of Endocrinology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
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Does LKB1 mediate activation of hepatic AMP-protein kinase (AMPK) and sirtuin1 (SIRT1) after Roux-en-Y gastric bypass in obese rats? J Gastrointest Surg 2010; 14:221-8. [PMID: 19937189 DOI: 10.1007/s11605-009-1102-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 11/03/2009] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Roux-en-Y gastric bypass (RYGB) improves steatosis and reduces liver triglycerides in obese rats. Sirtuin1 (SIRT1) and AMP-activated protein kinase (AMPK) are key metabolic regulators that reduce lipogenesis and increase fatty acid oxidation. LKB1 phosphorylates AMPK and may activate SIRT1. We hypothesize that RYGB in obese rats is associated with an upregulation of the LKB1-AMPK-SIRT1 signaling pathway. METHODS Obese Sprague-Dawley male rats underwent RYGB or sham. Liver tissue was obtained at 9 weeks postoperatively. Protein levels of SIRT1, LKB1, p-LKB1, AMPKalpha, p-AMPKalpha, and p-protein kinase C-zeta (PKC-zeta ) were determined. Protein associations of LKB1 with each of SIRT1, AMPKalpha, and PKC-zeta were determined by coimmunoprecipitation.Data are mean +/- SD; for t test, p<0.05 was significant. RESULTS RYGB increased protein levels of hepatic AMPKalpha, p-AMPKalpha, and SIRT1 (all p<0.001 vs. sham); p-LKB1 but not LKB1 increased after RYGB (p<0.001 vs. sham). Physical interactions of LKB1-AMPK and LKB1-SIRT1 increased after RYGB (p<0.001 vs. sham). Although PKC-zeta mRNA and p-PKC-zeta did not change, interactions between LKB1 and PKC-zeta increased after RYGB (p<0.001 vs. sham). CONCLUSION RYGB increases hepatic levels of SIRT1, AMPK, and p-AMPK as well as increasing interactions of LKB1 with AMPK or SIRT1. p-PKC-zeta may play an intermediary role in the interaction between AMPK and SIRT. These findings demonstrate key signaling changes in powerful metabolic regulators that may account for the resolution of steatosis after RYGB.
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Hursting SD, Smith SM, Lashinger LM, Harvey AE, Perkins SN. Calories and carcinogenesis: lessons learned from 30 years of calorie restriction research. Carcinogenesis 2009; 31:83-9. [PMID: 19969554 DOI: 10.1093/carcin/bgp280] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Calorie restriction (CR) is arguably the most potent, broadly acting dietary regimen for suppressing the carcinogenesis process, and many of the key studies in this field have been published in Carcinogenesis. Translation of the knowledge gained from CR research in animal models to cancer prevention strategies in humans is urgently needed given the worldwide obesity epidemic and the established link between obesity and increased risk of many cancers. This review synthesizes the evidence on key biological mechanisms underlying many of the beneficial effects of CR, with particular emphasis on the impact of CR on growth factor signaling pathways and inflammatory processes and on the emerging development of pharmacological mimetics of CR. These approaches will facilitate the translation of CR research into effective strategies for cancer prevention in humans.
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Affiliation(s)
- Stephen D Hursting
- Department of Nutritional Sciences, The University of Texas at Austin, 103 West 24th Street, Austin, TX 78712, USA.
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Powers ET, Morimoto RI, Dillin A, Kelly JW, Balch WE. Biological and chemical approaches to diseases of proteostasis deficiency. Annu Rev Biochem 2009; 78:959-91. [PMID: 19298183 DOI: 10.1146/annurev.biochem.052308.114844] [Citation(s) in RCA: 841] [Impact Index Per Article: 56.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many diseases appear to be caused by the misregulation of protein maintenance. Such diseases of protein homeostasis, or "proteostasis," include loss-of-function diseases (cystic fibrosis) and gain-of-toxic-function diseases (Alzheimer's, Parkinson's, and Huntington's disease). Proteostasis is maintained by the proteostasis network, which comprises pathways that control protein synthesis, folding, trafficking, aggregation, disaggregation, and degradation. The decreased ability of the proteostasis network to cope with inherited misfolding-prone proteins, aging, and/or metabolic/environmental stress appears to trigger or exacerbate proteostasis diseases. Herein, we review recent evidence supporting the principle that proteostasis is influenced both by an adjustable proteostasis network capacity and protein folding energetics, which together determine the balance between folding efficiency, misfolding, protein degradation, and aggregation. We review how small molecules can enhance proteostasis by binding to and stabilizing specific proteins (pharmacologic chaperones) or by increasing the proteostasis network capacity (proteostasis regulators). We propose that such therapeutic strategies, including combination therapies, represent a new approach for treating a range of diverse human maladies.
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Affiliation(s)
- Evan T Powers
- Departments of Chemistry and Molecular and Experimental Medicine and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Association of SIRT1 gene variation with visceral obesity. Hum Genet 2008; 124:431-6. [PMID: 18820948 DOI: 10.1007/s00439-008-0567-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 09/20/2008] [Indexed: 10/21/2022]
Abstract
The sirtuin SIRT1 is an important regulator of energy metabolism through its impact on glucose and lipid metabolism and therefore we tested the hypothesis that genetic variation in SIRT1 may have an effect on adiposity in a Belgian case/control association study. This study included 1,068 obese patients (BMI > or = 30 kg/m(2)) from the outpatient obesity clinic and 313 lean controls (BMI between 18.5 and 25 kg/m(2)). Anthropometrics were assessed by classical methods and visceral (VFA), subcutaneous (SFA) and total abdominal (TFA) fat areas were determined by a CT scan. The extent of linkage disequilibrium in SIRT1 allowed us to reduce the number of SNPs to two, sufficient to cover the entire gene. The two tagSNPs (rs7069102 and rs3818292) were analyzed by LightSNiP assays in all subjects. Rs3818292 genotypes were similarly distributed in cases and controls, whereas rs7069102 was different for the additive (P = 0.007) and dominant (P = 0.01) model. The variant C-allele of rs7069102 reduced obesity risk with an OR of 0.74 (P = 0.025; 95% CI 0.57-0.96) under a dominant model. In obese male subjects, this variant allele was associated with increased waist circumference (P = 0.04), WHR (P = 0.02), TFA (P = 0.03) and VFA (P = 0.005) (dominant model; adjusted for age and BMI). Rs3818292 was related to VFA (P = 0.005; adjusted for age and BMI) in obese males while in obese women, no significant associations were detected. Our data suggest that genetic variation in SIRT1 increases the risk for obesity, and that SIRT1 genotype correlates with visceral obesity parameters in obese men.
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