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Isolation and Characterization of Three Sodium-Phosphate Cotransporter Genes and Their Transcriptional Regulation in the Grass Carp Ctenopharyngodon idella. Int J Mol Sci 2020; 21:ijms21218228. [PMID: 33153158 PMCID: PMC7662828 DOI: 10.3390/ijms21218228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 12/20/2022] Open
Abstract
It is important to explore the regulatory mechanism of phosphorus homeostasis in fish, which help avoid the risk of P toxicity and prevent P pollution in aquatic environment. The present study obtained the full-length cDNA sequences and the promoters of three SLC20 members (slc20a1a, slc20a1b and slc20a2) from grass carp Ctenopharyngodon idella, and explored their responses to inorganic phosphorus (Pi). Grass carp SLC20s proteins possessed conservative domains and amino acid sites relevant with phosphorus transport. The mRNAs of three slc20s appeared in the nine tissues, but their expression levels were tissue-dependent. The binding sites of three transcription factors (SREBP1, NRF2 and VDR) were predicted on the slc20s promoters. The mutation and EMSA analysis indicated that: (1) SREBP1 binding site (−783/−771 bp) negatively but VDR (−260/−253 bp) binding site positively regulated the activities of slc20a1a promoter; (2) SREBP1 (−1187/−1178 bp), NRF2 (−572/−561 bp) and VDR(615/−609 bp) binding sites positively regulated the activities of slc20a1b promoter; (3) SREBP1 (−987/−977 bp), NRF2 (−1469/−1459 bp) and VDR (−1124/−1117 bp) binding sites positively regulated the activities of the slc20a2 promoter. Moreover, Pi incubation significantly reduced the activities of three slc20s promoters, and Pi-induced transcriptional inactivation of slc20s promoters abolished after the mutation of the VDR element but not SREBP1 and NRF2 elements. Pi incubation down-regulated the mRNA levels of three slc20s. For the first time, our study elucidated the transcriptional regulatory mechanisms of SLC20s and their responses to Pi, which offered new insights into the Pi homeostatic regulation and provided the basis for reducing phosphorus discharge into the waters.
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Oriquat GA, Ali MA, Mahmoud SA, Eid RMHM, Hassan R, Kamel MA. Improving hepatic mitochondrial biogenesis as a postulated mechanism for the antidiabetic effect of Spirulina platensis in comparison with metformin. Appl Physiol Nutr Metab 2018; 44:357-364. [PMID: 30208279 DOI: 10.1139/apnm-2018-0354] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Various nutritional and medicinal potencies have been accredited to metabolites from the cyanobacteria, Spirulina platensis (Arthrospira platensis) sp. Hence, our study was designed to examine whether the Spirulina supplementation would possess beneficial effects in type 2 diabetes mellitus (T2DM) in comparison with metformin. High-fat diet/low-dose streptozotocin (HFD/STZ) model was adopted and the diabetic rats were orally treated with metformin (200 mg/kg) or Spirulina (250 or 500 or 750 mg/kg) for 30 days. Spirulina ameliorated the HFD/STZ-induced elevation of fasting blood glucose, insulin, and hepatic enzymes. Moreover, Spirulina successfully rectified disrupted serum lipid profile and exhibited an anti-inflammatory effect via tumor necrosis factor-α and adiponectin modulation. On the molecular level, Spirulina reduced the expression of hepatic sterol regulatory element binding protein-1c (SREBP-1c), confirming its lipotropic effect. Furthermore, Spirulina amended compromised hepatic mitochondrial biogenesis signaling by significantly increasing peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α), mitochondrial transcription factor A (Tfam), and mitochondrial DNA (mtDNA) copy number. On almost all parameters, the highest dose of Spirulina showed the best effects, which were comparable to that of metformin. To our knowledge, our study is the first to attribute the various aspects of the effect of Spirulina to the SREBP-1c and PGC-1α/Tfam/mtDNA pathways in liver. The present results clearly proved that Spirulina modulated glucose/lipid profile and exhibited prominent anti-inflammatory properties through SREBP-1c inhibition and hepatic mitochondrial biogenesis enhancement. Thus, Spirulina can be considered as an add-on to conventional antidiabetic agents and might influence the whole dynamics of the therapeutic approaches in T2DM.
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Affiliation(s)
- Ghaleb A Oriquat
- a Faculty of Pharmacy and Medical Sciences, Al-Ahliyya Amman University, Amman 19328, Jordan
| | - Mennatallah A Ali
- b Department of Pharmacology & Therapeutics, Faculty of Pharmacy and Drug Manufacturing, Pharos University in Alexandria, PO Box 37, Alexandria 21648, Egypt
| | - Shimaa A Mahmoud
- c Department of Biochemistry, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt
| | - Rania M H M Eid
- d Department of Physiology, Faculty of Medicine, Aswan University, Aswan 81528, Egypt
| | - Rania Hassan
- e Department of Biochemistry, Faculty of Physical Therapy, Pharos University in Alexandria, Alexandria 21648, Egypt
| | - Maher A Kamel
- c Department of Biochemistry, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt
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Rafeeq MM, Habib HS, Murad HAS, Gari MA, Gazzaz ZJ. Effect of genetic polymorphisms in SREBF-SCAP pathway on therapeutic response to rosuvastatin in Saudi metabolic syndrome patients. Pharmacogenomics 2018; 19:185-196. [PMID: 29318930 DOI: 10.2217/pgs-2017-0181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Genetic variants contribute to statins' therapeutic variability. SREBF-SCAP pathway is a key player in lipid homeostasis. Hence, effect of SREBF-SCAP polymorphisms on therapeutic response was studied. PATIENTS & METHODS Metabolic syndrome patients of either sex were prescribed rosuvastatin 10 mg for 24 weeks. Clinical, anthropometric and lipid measurements were done before and after treatment. Genotyping was done by pyrosequencing. RESULTS & CONCLUSION No associations of SCAP and SREBF-1a genotypes with baseline lipids but significant associations with lipid reductions were observed. Significant effect of SCAP (GG; B = -8.16, p = 0.001); SREBF-1a (GG; B = -7.47, p = 0.001) and SREBF-1a (-delG; B = -7.42, p = 0.001) was observed on total cholesterol reduction. Additive trend was found between SCAP genotypes and lipid reductions. A total of 88% responders have SCAP 'G' allele (p = 0.001). Patients carrying SCAP (GG) and SREBF-1a (GG and -delG) have 9.5-, 8.6- and 14.6-times more likelihood of being responders (p < 0.05). 'G' allele in SCAP and SREBF-1a is significant predictor of rosuvastatin response.
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Affiliation(s)
- Misbahuddin Mohd Rafeeq
- Department of Pharmacology, Faculty of Medicine, Rabigh Campus, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hamed Said Habib
- Department of Paediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hussam Aly Sayed Murad
- Department of Pharmacology, Faculty of Medicine, Rabigh Campus, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Pharmacology, Faculty of Medicine, Rabigh Campus, King Abdulaziz University, Jeddah, Saudi Arabia & Faculty of Medicine, Ainshams University, Cairo, Egypt
| | - Mamdouh Abdullah Gari
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Zohair Jamil Gazzaz
- Department of Internal Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
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Abudesimu A, Adi D, Siti D, Xie X, Yang YN, Li XM, Wang YH, Wang YT, Meng YJ, Liu F, Chen BD, Ma X, Fu ZY, Ma YT. Association of genetic variations in the lipid regulatory pathway genes FBXW7 and SREBPs with coronary artery disease among Han Chinese and Uygur Chinese populations in Xinjiang, China. Oncotarget 2017; 8:88199-88210. [PMID: 29152152 PMCID: PMC5675704 DOI: 10.18632/oncotarget.21082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/05/2017] [Indexed: 12/28/2022] Open
Abstract
Background Hyperlipidemia is a major risk factor for coronary artery disease (CAD). The current study was designed to explore the possible correlation between single nucleotide polymorphisms (SNPs) in the lipid homeostasis regulatory genes F-box and WD repeat domain-containing 7 (FBXW7) and sterol regulatory element-binding proteins (SREBPs) with CAD among Han Chinese and Uygur Chinese populations in Xinjiang, China. Results In the Uygur Chinese population, rs9902941 in SREBP-1 and rs10033601 in FBXW7 were found to be associated with CAD in a recessive model (TT vs. CT + CC, P = 0.032; GG vs. AG + AA, P = 0.010, respectively), and rs7288536 in SREBP-2 was found to be associated with CAD in an additive model (CT vs. CC + TT, P = 0.045). The difference was statistically significant in the Uygur Chinese population after multivariate adjustments [Odds ratio (OR) = 1.803, 95% confidence interval (CI): 1.036~3.137, P = 0.037; OR = 1.628, 95% CI: 1.080~2.454, P = 0.020; OR = 1.368; and 95% CI: 1.018~1.837, P = 0.037, respectively]. There were also significant interactions between the above-mentioned models in the Uygur Chinese population. However, these relationships were not observed before or after multivariate adjustment in the Han Chinese population. Materials and Methods A total of 1,312 Han Chinese (650 CAD patients and 662 controls) and 834 Uygur Chinese (414 CAD patients and 420 controls) were enrolled in this case-control study. Three SNPs (rs9902941 in SREBP-1, rs7288536 in SREBP-2 and rs10033601 in FBXW7) were selected and genotyped using the improved multiplex ligase detection reaction (iMLDR) method. Conclusions The results of this study indicate that variations in the lipid regulatory pathway genes FBXW7 and SREBPs (rs9902941 in SREBP-1, rs7288536 in SREBP-2 and rs10033601 in FBXW7) are associated with CAD in the Uygur Chinese population in Xinjiang, China.
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Affiliation(s)
- Asiya Abudesimu
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Dilare Adi
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Dilixiati Siti
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Xiang Xie
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Yi-Ning Yang
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Xiao-Mei Li
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Ying-Hong Wang
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Yong-Tao Wang
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Ya-Jie Meng
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Fen Liu
- Xinjiang Key Laboratory of Cardiovascular Disease, Clinical Medical Research Institute of First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Bang-Dang Chen
- Xinjiang Key Laboratory of Cardiovascular Disease, Clinical Medical Research Institute of First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Xiang Ma
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Zhen-Yan Fu
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
| | - Yi-Tong Ma
- Department of Cardiology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, PR China
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Paththinige CS, Sirisena ND, Dissanayake V. Genetic determinants of inherited susceptibility to hypercholesterolemia - a comprehensive literature review. Lipids Health Dis 2017; 16:103. [PMID: 28577571 PMCID: PMC5457620 DOI: 10.1186/s12944-017-0488-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/17/2017] [Indexed: 02/08/2023] Open
Abstract
Hypercholesterolemia is a strong determinant of mortality and morbidity associated with cardiovascular diseases and a major contributor to the global disease burden. Mutations in four genes (LDLR, APOB, PCSK9 and LDLRAP1) account for the majority of cases with familial hypercholesterolemia. However, a substantial proportion of adults with hypercholesterolemia do not have a mutation in any of these four genes. This indicates the probability of having other genes with a causative or contributory role in the pathogenesis of hypercholesterolemia and suggests a polygenic inheritance of this condition. Here in, we review the recent evidence of association of the genetic variants with hypercholesterolemia and the three lipid traits; total cholesterol (TC), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C), their biological pathways and the associated pathogenetic mechanisms. Nearly 80 genes involved in lipid metabolism (encoding structural components of lipoproteins, lipoprotein receptors and related proteins, enzymes, lipid transporters, lipid transfer proteins, and activators or inhibitors of protein function and gene transcription) with single nucleotide variants (SNVs) that are recognized to be associated with hypercholesterolemia and serum lipid traits in genome-wide association studies and candidate gene studies were identified. In addition, genome-wide association studies in different populations have identified SNVs associated with TC, HDL-C and LDL-C in nearly 120 genes within or in the vicinity of the genes that are not known to be involved in lipid metabolism. Over 90% of the SNVs in both these groups are located outside the coding regions of the genes. These findings indicates that there might be a considerable number of unrecognized processes and mechanisms of lipid homeostasis, which when disrupted, would lead to hypercholesterolemia. Knowledge of these molecular pathways will enable the discovery of novel treatment and preventive methods as well as identify the biochemical and molecular markers for the risk prediction and early detection of this common, yet potentially debilitating condition.
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Affiliation(s)
- C S Paththinige
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka.
| | - N D Sirisena
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka
| | - Vhw Dissanayake
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka
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Rafeeq MM, Ahmad F, Rahman SZ, Siddiqi SS, Shakil S. Effect of an SNP in SCAP gene on lipid-lowering response to rosuvastatin in Indian patients with metabolic syndrome. Pharmacogenomics 2016; 17:2015-2024. [PMID: 27885915 DOI: 10.2217/pgs.16.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
AIM Statins treat dyslipidemia associated with metabolic syndrome. Genetic factors contribute to variable response. Sterol regulatory element-binding factors cleavage-activating protein (SCAP) pathway regulates lipid homeostasis, so effect of SNP in SCAP gene on rosuvastatin response was studied. MATERIALS & METHODS Metabolic syndrome patients with low-density lipoprotein-cholesterol ≥130 mg/dl, were prescribed rosuvastatin 5 mg for 3 months. Lipids were measured initially and finally, and genotyping done. RESULTS & CONCLUSION Sixty-three patients completed the study. Twenty-three were homozygous for AA while 40 were heterozygous. Significant association was found between post-treatment lipid values and SCAP genotypes but not with baseline values. Cholesterol (p = 0.002) and low-density lipoprotein-cholesterol (p = 0.008) were significantly reduced in patients carrying G allele as compared with AA. There was a significant effect of G allele on cholesterol reduction (p = 0.043). Out of total responders (achieving >23.58% total cholesterol reduction), 80.5% were 2386G carriers (GG+GA) and only 19.5% were homozygous for A allele (p = 0.0048). SCAP 2386A>G gene polymorphism is a significant predictor of hypolipidemic response.
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Affiliation(s)
- Misbahuddin M Rafeeq
- Department of Pharmacology, Rabigh College of Medicine, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Farida Ahmad
- Department of Pharmacology, Faculty of Medicine, Aligarh Muslim University, Aligarh, 202002, India
| | - Syed Z Rahman
- Department of Pharmacology, Faculty of Medicine, Aligarh Muslim University, Aligarh, 202002, India
| | - Sheelu S Siddiqi
- Rajiv Gandhi Centre for Diabetes & Endocrinology, Faculty of Medicine, Aligarh Muslim University, Aligarh, 202002, India
| | - Shazi Shakil
- Centre for Innovation in Personalized Medicine, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
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Miranzadeh-Mahabadi H, Emadi-Baygi M, Nikpour P, Kelishadi R. Association Study Between Metabolic Syndrome and rs8066560 Polymorphism in the Promoter Region of Sterol Regulatory Element-binding Transcription Factor 1 Gene in Iranian Children and Adolescents. Int J Prev Med 2016; 7:41. [PMID: 27076879 PMCID: PMC4809125 DOI: 10.4103/2008-7802.177314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/22/2015] [Indexed: 11/17/2022] Open
Abstract
Background: Metabolic syndrome (MetS) is a prevalent disorder in pediatric age groups, described by a combination of genetic and environmental factors. Sterol regulatory element-binding transcription factor 1 (SREBF-1) induces the expression of a family of genes involved in fatty acid synthesis. Moreover, dysregulation of miR-33b, which is located within the intron 17 of the SREBF-1 gene, disrupts fatty acid oxidation and insulin signaling, thus leading to MetS. The aim of the present study was to investigate the association between SREBF-1 rs8066560 polymorphism and MetS in Iranian children and adolescents. Methods: This study includes 100 MetS and 100 normal individuals aged 9–19 years. Anthropological and biochemical indexes were measured. The -1099G > A polymorphism was genotyped by TaqMan real-time polymerase chain reaction. Results: Significant differences were observed in anthropometric measurements and lipid profiles between MetS and normal children. There were no differences in the genotype frequencies or allele distribution for -1099G > A polymorphism between MetS and control groups. High-density lipoprotein cholesterol levels were significantly higher in the MetS GG group than in the A allele carrier group. The genotype AA controls had significantly increased cholesterol and low-density lipoprotein cholesterol levels than AG genotypes. By logistic regression using different genetic models, no significant association was observed between SREBF-1 rs8066560 polymorphism and the risk of MetS. Conclusions: We conclude that the -1099G > A variant on SREBF-1 gene associated with serum lipid profiles, however, it may not be a major risk factor for the MetS in Iranian children and adolescents.
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Affiliation(s)
- Hajar Miranzadeh-Mahabadi
- Department of Genetics, School of Basic Sciences, Shahrekord University, Shahrekord, Iran; Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Modjtaba Emadi-Baygi
- Department of Genetics, School of Basic Sciences, Shahrekord University, Shahrekord, Iran; Research Institute of Biotechnology, Shahrekord University, Shahrekord, Iran
| | - Parvaneh Nikpour
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran; Applied Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Roya Kelishadi
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
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Zhao X, Xiaoli, Zong H, Abdulla A, Yang EST, Wang Q, Ji JY, Pessin JE, Das BC, Yang F. Inhibition of SREBP transcriptional activity by a boron-containing compound improves lipid homeostasis in diet-induced obesity. Diabetes 2014; 63:2464-73. [PMID: 24608444 PMCID: PMC4066337 DOI: 10.2337/db13-0835] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dysregulation of lipid homeostasis is intimately associated with obesity, type 2 diabetes, and cardiovascular diseases. Sterol regulatory-element binding proteins (SREBPs) are the master regulators of lipid biosynthesis. Previous studies have shown that the conserved transcriptional cofactor Mediator complex is critically required for the SREBP transcriptional activity, and recruitment of the Mediator complex to the SREBP transactivation domains (TADs) is through the MED15-KIX domain. Recently, we have synthesized several boron-containing small molecules. Among these novel compounds, BF175 can specifically block the binding of MED15-KIX to SREBP1a-TAD in vitro, resulting in an inhibition of the SREBP transcriptional activity and a decrease of SREBP target gene expression in cultured hepatocytes. Furthermore, BF175 can improve lipid homeostasis in the mouse model of diet-induced obesity. Compared with the control, BF175 treatment decreased the expression of SREBP target genes in mouse livers and decreased hepatic and blood levels of lipids. These results suggest that blocking the interaction between SREBP-TADs and the Mediator complex by small molecules may represent a novel approach for treating diseases with aberrant lipid homeostasis.
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Affiliation(s)
- Xiaoping Zhao
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NYDepartment of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaoli
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Haihong Zong
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Arian Abdulla
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Ellen S T Yang
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Qun Wang
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX
| | - Jeffrey E Pessin
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY
| | - Bhaskar C Das
- Division of Hematology and Oncology, Department of Medicine, University of Kansas Medical Center, Kansas City, KS
| | - Fajun Yang
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
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The gene-gene interaction of INSIG-SCAP-SREBP pathway on the risk of obesity in Chinese children. BIOMED RESEARCH INTERNATIONAL 2014; 2014:538564. [PMID: 25028659 PMCID: PMC4083216 DOI: 10.1155/2014/538564] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/26/2014] [Indexed: 11/20/2022]
Abstract
Background. Childhood obesity has become a global public health problem in recent years. This study aimed to explore the association of genetic variants in INSIG-SCAP-SREBP pathway with obesity in Chinese children. Methods. A case-control study was conducted, including 705 obese cases and 1,325 nonobese controls. We genotyped 15 single nucleotide polymorphisms (SNPs) of five genes in INSIG-SCAP-SREBP pathway, including insulin induced gene 1 (INSIG1), insulin induced gene 2 (INSIG2), SREBP cleavage-activating protein gene (SCAP), sterol regulatory element binding protein gene 1 (SREBP1), and sterol regulatory element binding protein gene 2 (SREBP2). We used generalized multifactor dimensionality reduction (GMDR) and logistic regression to investigate gene-gene interactions. Results. Single polymorphism analyses showed that SCAP rs12487736 and rs12490383 were nominally associated with obesity. We identified a 3-locus interaction on obesity in GMDR analyses (P = 0.001), involving 3 genetic variants of INSIG2, SCAP, and SREBP2. The individuals in high-risk group of the 3-locus combinations had a 79.9% increased risk of obesity compared with those in low-risk group (OR = 1.799, 95% CI: 1.475–2.193, P = 6.61 × 10−9). Conclusion. We identified interaction of three genes in INSIG-SCAP-SREBP pathway on risk of obesity, revealing that these genes affect obesity more likely through a complex interaction pattern than single gene effect.
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The Association Study between Twenty One Polymorphisms in Seven Candidate Genes and Coronary Heart Diseases in Chinese Han Population. PLoS One 2013; 8:e66976. [PMID: 23840567 PMCID: PMC3694109 DOI: 10.1371/journal.pone.0066976] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 05/13/2013] [Indexed: 12/23/2022] Open
Abstract
Previous genome-wide association studies (GWAS) in multiple populations identified several genetic loci for coronary heart diseases (CHD). Here we utilized a 2-stage candidate gene association strategy in Chinese Han population to shed light on the putative association between several metabolic-related candidate genes and CHD. At the 1st stage, 190 patients with CHD and 190 controls were genotyped through the MassARRAY platform. At the 2nd stage, a larger sample including 400 patients and 392 controls was genotyped by the High Resolution Melt (HRM) method to confirm or rule out the associations with CHD. MLXIP expression level was quantified by the real time PCR in 65 peripheral blood samples. From the 21 studied single nucleotide polymorphisms (SNPs) of seven candidate genes: MLXIPL, MLXIP, MLX, ADIPOR1, VDR, SREBF1 and NR1H3, only one tag SNP rs4758685 (T→C) was found to be statistically associated with CHD (P-value = 0.02, Odds ratio (OR) of 0.83). After adjustment for the age, sex, lipid levels and diabetes, the association remained significant (P-value = 0.03). After adjustment for the hypertension, P-value became 0.20 although there was a significant difference in the allele distribution between the CHD patients with hypertension and the controls (P-value = 0.04, 406 vs 582). In conclusion, among the 21 tested SNPs, we identified a novel association between rs4758685 of MLXIP gene and CHD. The C allele of common variant rs4758685 interacted with hypertension, and was found to be protective against CHD in both allelic and genotypic models in Chinese Han population.
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Abstract
The sterol regulatory element-binding proteins (SREBPs) play an important role in regulating lipid homeostasis. Translated as inactive precursors that are localized in the endoplasmic reticulum (ER) membrane, SREBPs are activated through a proteolytic process in response to intracellular demands for lipids. The cleaved amino-terminal fragments of SREBPs then translocate into the nucleus as homodimers and stimulate the transcription of target genes by binding to the sterol response elements (SREs) in their promoters. Numerous studies using cell culture or genetically modified mouse models have demonstrated that the major target genes of SREBPs include rate-limiting enzymes in the pathways of fatty acid and cholesterol biosynthesis as well as the low-density lipoprotein (LDL) receptor. The proteolytic maturation of SREBPs has been well studied in the past. However, recent studies have also improved our understanding on the regulation of nuclear SREBPs. In the nucleus, SREBPs interact with specific transcriptional cofactors, such as CBP/p300 and the Mediator complex, resulting in stimulation or inhibition of their transcriptional activities. In addition, nuclear SREBP protein stability is dynamically regulated by phosphorylation and acetylation. Such protein-protein interactions and post-translational modifications elegantly link the extracellular signals, such as insulin, or intracellular signals, such as oxidative stress, to lipid biosynthesis by modulating the transcriptional activity of SREBPs. Under normal physiological states, lipid homeostasis is strictly maintained. However, the SREBP pathways are often dysregulated in pathophysiological conditions, such as obesity, type 2 diabetes, and fatty liver diseases. Thus, the novel regulatory mechanisms of SREBPs may provide new opportunities for fighting these metabolic diseases.
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Adeli K. Translational control mechanisms in metabolic regulation: critical role of RNA binding proteins, microRNAs, and cytoplasmic RNA granules. Am J Physiol Endocrinol Metab 2011; 301:E1051-64. [PMID: 21971522 DOI: 10.1152/ajpendo.00399.2011] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Regulated cell metabolism involves acute and chronic regulation of gene expression by various nutritional and endocrine stimuli. To respond effectively to endogenous and exogenous signals, cells require rapid response mechanisms to modulate transcript expression and protein synthesis and cannot, in most cases, rely on control of transcriptional initiation that requires hours to take effect. Thus, co- and posttranslational mechanisms have been increasingly recognized as key modulators of metabolic function. This review highlights the critical role of mRNA translational control in modulation of global protein synthesis as well as specific protein factors that regulate metabolic function. First, the complex lifecycle of eukaryotic mRNAs will be reviewed, including our current understanding of translational control mechanisms, regulation by RNA binding proteins and microRNAs, and the role of RNA granules, including processing bodies and stress granules. Second, the current evidence linking regulation of mRNA translation with normal physiological and metabolic pathways and the associated disease states are reviewed. A growing body of evidence supports a key role of translational control in metabolic regulation and implicates translational mechanisms in the pathogenesis of metabolic disorders such as type 2 diabetes. The review also highlights translational control of apolipoprotein B (apoB) mRNA by insulin as a clear example of endocrine modulation of mRNA translation to bring about changes in specific metabolic pathways. Recent findings made on the role of 5'-untranslated regions (5'-UTR), 3'-UTR, RNA binding proteins, and RNA granules in mediating insulin regulation of apoB mRNA translation, apoB protein synthesis, and hepatic lipoprotein production are discussed.
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Affiliation(s)
- Khosrow Adeli
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Atrium 3653, 555 University Ave., Toronto, ON, M5G 1X8 Canada.
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Arazi SS, Genvigir FDV, Willrich MAV, Hirata MH, Dorea EL, Bernik M, Hirata RDC. Atorvastatin effects on SREBF1a and SCAP gene expression in mononuclear cells and its relation with lowering-lipids response. Clin Chim Acta 2008; 393:119-24. [PMID: 18435918 DOI: 10.1016/j.cca.2008.03.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 03/24/2008] [Accepted: 03/25/2008] [Indexed: 01/29/2023]
Abstract
BACKGROUND The transcription factors SREBP1 and SCAP are involved in intracellular cholesterol homeostasis. Polymorphisms of these genes have been associated with variations on serum lipid levels and response to statins that are potent cholesterol-lowering drugs. We evaluated the effects of atorvastatin on SREBF1a and SCAP mRNA expression in peripheral blood mononuclear cells (PBMC) and a possible association with gene polymorphisms and lowering-cholesterol response. METHODS Fifty-nine hypercholesterolemic patients were treated with atorvastatin (10 mg/day for 4 weeks). Serum lipid profile and mRNA expression in PBMC were assessed before and after the treatment. Gene expression was quantified by real-time PCR using GAPD as endogenous reference and mRNA expression in HepG2 cells as calibrator. SREBF1 -36delG and SCAP A2386G polymorphisms were detected by PCR-RFLP. RESULTS Our results showed that transcription of SREBF1a and SCAP was coordinately regulated by atorvastatin (r=0.595, p<0.001), and that reduction in SCAP transcription was associated with the 2386AA genotype (p=0.019). Individuals who responded to atorvastatin with a downregulation of SCAP had also a lower triglyceride compared to those who responded to atorvastatin with an upregulation of SCAP. CONCLUSION Atorvastatin has differential effects on SREBF1a and SCAP mRNA expression in PBMC that are associated with baseline transcription levels, triglycerides response to atorvastatin and SCAP A2386G polymorphism.
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Affiliation(s)
- Simone Sorkin Arazi
- School of Pharmaceutical Sciences - University of Sao Paulo, Sao Paulo, SP, Brazil.
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Friedlander Y, Schwartz SM, Durst R, Meiner V, Robertson AS, Erez G, Leitersdorf E, Siscovick DS. SREBP-2 and SCAP isoforms and risk of early onset myocardial infarction. Atherosclerosis 2008; 196:896-904. [PMID: 17383658 DOI: 10.1016/j.atherosclerosis.2007.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 01/09/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Cholesterol metabolism is mediated, in part, by the sterol-regulatory element binding proteins (SREBPs) that are activated by a SREBP cleavage-activating protein (SCAP). We examined whether coding variations in the interacting domains of both genes, are related to early-onset MI risk in a population-based case-control study from western Washington State. METHODS Cases were 257 women, aged 18-59 years, and 320 men, aged 18-49 years, with first acute non-fatal MI; controls were 353 women and 311 men, similar in age, identified from the community who had no history of clinical CHD or stroke. Genotyping of the SREBF-2 G1784C polymorphism (SREBP-2-595A/G isoforms), and the SCAP A2386G polymorphism (SCAP-796I/V isoforms), were performed. RESULTS After adjustment for age and race, the SREBP-2-595A isoform was associated with increased MI risk among men (OR=1.63, 95% CI=1.26-2.12). In contrast, there was little evidence for an association among women in a multiplicative model. However, compared to SREBP-2-595G homozygotes, homozygote women for the SREBP-2-595A isoform were at nearly two-fold increased risk (OR=1.95, 95% CI=1.07-3.54). Overall, SCAP genotypes were neither associated with MI in men nor in women. However, in men, SCAP genotypes were found to modify the association between SREBF-2 and MI (p-value for interaction=0.01). CONCLUSION The SREBP-2-595A isoform was associated with an increased risk of early-onset MI in U.S. men. The SCAP polymorphism appeared to modify the associations of SREBF-2 genotype with MI risk among men. These novel findings require confirmation in other populations.
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Affiliation(s)
- Yechiel Friedlander
- Unit of Epidemiology, Hebrew University-Hadassah School of Public Health, Jerusalem, Israel
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15
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Genotype of bovine sterol regulatory element binding protein-1 (SREBP-1) is associated with fatty acid composition in Japanese Black cattle. Mamm Genome 2007; 18:880-6. [PMID: 18049837 DOI: 10.1007/s00335-007-9072-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 10/10/2007] [Indexed: 10/22/2022]
Abstract
To investigate genetic factors that affect fatty acid composition in beef carcass, we previously investigated genetic profiles of stearoyl-CoA desaturase (SCD) and their effect on fatty acid composition in fat tissue of cattle. It has been known that sterol regulatory element binding protein (SREBP) is a transcription factor that regulates gene expression levels of SCD and other genes relevant to lipid and fatty acid metabolism in tissue. Therefore, we determined the full-length sequence of bovine SREBP-1 cDNA and then surveyed polymorphisms in whole exons and introns in the bovine genome. Large 84-bp insertion (long type: L) and deletion (short type: S) were found in intron 5 of bovine SREBP-1 in Japanese Black cattle, although there was no notable mutation in exon regions. The associations between the SREBP-1 genotypes and fatty acid compositions/fat melting points were analyzed by using genomic DNA with carcass trait information from 606 Japanese Black cattle. The S type contributed to 1.3% higher monounsaturated fatty acid (MUFA) proportion and 1.6 degrees C lower melting point in intramuscular fat. Genotyping of bovine SREBP-1 is considered to reflect a genetic variation which is associated with physiologic characteristics of fat tissue in Japanese black cattle.
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Raeder MB, Fernø J, Vik-Mo AO, Steen VM. SREBP activation by antipsychotic- and antidepressant-drugs in cultured human liver cells: relevance for metabolic side-effects? Mol Cell Biochem 2006; 289:167-73. [PMID: 16718372 DOI: 10.1007/s11010-006-9160-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 02/15/2006] [Indexed: 12/20/2022]
Abstract
Drug-induced weight gain is a major problem in the treatment of psychiatric disorders, especially with some antipsychotic- and antidepressant drugs. We have recently demonstrated that antipsychotic- and antidepressant drugs activate the SREBP (sterol regulatory element-binding proteins) transcription factors in human- and rat glial cells, with subsequent up-regulation of downstream genes involved in cholesterol- and fatty acid biosynthesis. Since stimulation of cellular lipogenesis in the liver could be of relevance for the metabolic side effects of these drugs, we have now investigated the effects of antidepressants, antipsychotic- and mood-stabilizing drugs on cell cultures of human liver cells. For several of the drugs being strongly associated with weight gain (clozapine, imipramine, and amitriptyline), we observed a very pronounced activation of SREBP. Ziprasidone and buproprion, however, which are not associated with weight gain, did hardly stimulate the SREBP system. For haloperidol, olanzapine and mirtazapine, the correspondence between metabolic side effects and SREBP stimulation in liver cells was less obvious. The mood-stabilizers did not increase SREBP activation. The results indicate a relationship between drug-induced activation of SREBP in cultured human liver cells and weight gain side-effects of antidepressant and antipsychotic drugs.
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Affiliation(s)
- Maria B Raeder
- Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Helse, Bergen HF, N-5021, Norway.
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Fiegenbaum M, Silveira FR, Van der Sand CR, Van der Sand LC, Ferreira MEW, Pires RC, Hutz MH. Determinants of variable response to simvastatin treatment: the role of common variants of SCAP, SREBF-1a and SREBF-2 genes. THE PHARMACOGENOMICS JOURNAL 2005; 5:359-64. [PMID: 16158080 DOI: 10.1038/sj.tpj.6500334] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We investigated the effect of single-nucleotide polymorphisms in sterol regulatory element-binding factors-1a and -2 (SREBF-1a and SREBF-2) and SREBF cleavage-activating protein (SCAP) genes on lipid-lowering response to simvastatin. In all, 146 hypercholesterolemic patients of European descent were prospectively treated with simvastatin 20 mg/day for over 6 months. Of these 99 subjects completed the 6-month follow-up. Plasma lipids and lipoproteins were measured before and throughout the study. The mean percentage decrease in plasma total cholesterol (TC) was greater in subject carriers of SCAP 2386G allele compared with those homozygous for 2386A allele (-29.6+/-13.4 vs -22.1+/-13.8%, P=0.007). About 61% of the 2386G carriers were above-average responders for TC levels (DeltaTC -27.8%), whereas only 29% of 2386A homozygous reached this reduction (P=0.009). Our data suggest that the SCAP 2386A>G gene polymorphism was a significant predictor of TC and triglyceride responses to simvastatin treatment.
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Affiliation(s)
- M Fiegenbaum
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS, Brazil
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Laaksonen R, Thelen KM, Päivä H, Matinheikki J, Vesalainen R, Janatuinen T, Knuuti J, Rontu R, von Bergmann K, Lütjohann D, Lehtimäki T. Genetic variant of the SREBF-1 gene is significantly related to cholesterol synthesis in man. Atherosclerosis 2005; 185:206-9. [PMID: 16005884 DOI: 10.1016/j.atherosclerosis.2005.06.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 05/27/2005] [Accepted: 06/02/2005] [Indexed: 11/23/2022]
Abstract
Sterol regulatory element binding proteins-1 and -2 (SREBPs) are transcription factors controlling lipid homeostasis in human cells. The G-allele carriers of the SREBF-1 gene C-G polymorphism in exon 18c and coding for glycine at the protein level (G952G) have shown to associate more frequently with obesity and type 2 diabetes than the C-allele carriers. However, the C-allele has suggested to be linked to dyslipidemia. Thus, our aim was to study effect of the SREBF-1 gene polymorphism (G952G) on sterol metabolism in man. Ninety-five subjects with moderate hypercholesterolemia participated in this study and 14 homozygous CC carriers of the SREBF-1 (G952G) gene were found. Plasma lathosterol concentration and lathosterol-to-cholesterol ratio, markers of endogenous cholesterol synthesis, were significantly higher in CC homozygous subject compared to others. Similarly muscle cholesterol (p=0.045) and lathosterol (p=0.054) concentrations were elevated in the CC homozygotes supporting the view that endogenous cholesterol synthesis rate is SREBF-1 genotype-dependent.
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Affiliation(s)
- Reijo Laaksonen
- Department of Internal Medicine, University Hospital of Tampere, Tampere, Finland.
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Allen A, Belton C, Patterson C, Horan P, McGlinchey P, Spence M, Evans A, Fogarty D, McKeown P. Family-based association studies of lipid gene polymorphisms in coronary artery disease. Am J Cardiol 2005; 96:52-5. [PMID: 15979432 DOI: 10.1016/j.amjcard.2005.02.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 02/28/2005] [Accepted: 02/28/2005] [Indexed: 11/29/2022]
Abstract
Dysfunction of lipid-metabolizing proteins is implicated in the pathogenesis of coronary artery disease. Single nucleotide polymorphisms in genes that encode sterol regulatory binding protein-1a, adenosine triphosphate binding cassette-A1, hepatic lipase, lipoprotein lipase, and cholesteryl ester transfer protein were assessed as potential markers of disease susceptibility in a family-based study of 1,012 patients from 386 families. Association between single nucleotide polymorphisms and coronary artery disease was tested by the combined transmission disequilibrium test/sib transmission disequilibrium test and pedigree disequilibrium test. After Bonferroni's correction, the pedigree disequilibrium test demonstrated significant excess transmission (p <0.0083) to affected patients of the hepatic lipase -514 T allele, which suggests that this may constitute a novel disease-susceptibility locus.
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Affiliation(s)
- Adrian Allen
- Department of Medicine, Queen's University Belfast, Belfast, Northern Ireland, UK
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Spell C, Kölsch H, Lütjohann D, Kerksiek A, Hentschel F, Damian M, von Bergmann K, Rao ML, Maier W, Heun R. SREBP-1a polymorphism influences the risk of Alzheimer's disease in carriers of the ApoE4 allele. Dement Geriatr Cogn Disord 2005; 18:245-9. [PMID: 15286454 DOI: 10.1159/000080023] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/14/2004] [Indexed: 11/19/2022] Open
Abstract
Sterol regulatory element-binding proteins (SREBPs) are transcription factors involved in cholesterol and fatty acid synthesis. Recently, a polymorphism in the 5'-region of the SREBP-1a gene has been described to be correlated with alterations in the plasma levels of cholesterol. Consequently the relationship between this SREBP-1a gene polymorphism and Alzheimer's disease (AD) alone and in combination with the apolipoprotein E (ApoE) 4 allele was evaluated. No association between SREBP-1a polymorphism alone and AD could be seen. However, in the group of healthy ApoE4 allele carriers, the number of homozygote SREBP-1a DeltaG allele carriers was significantly higher than in AD patients. Cerebrospinal fluid levels of cholesterol were lower in AD patients who were carriers of the SREBP-1a DeltaG allele, and the ratio of 24S-hydroxycholesterol to cholesterol was increased in these probands. Our data suggest a reduced risk of AD in carriers of an ApoE4 allele who are additionally homozygous for the SREBP-1a DeltaG allele, which is possibly due to the influence of SREBP-1a polymorphism on brain cholesterol metabolism. This is the first report on a genetic factor which prevents the deleterious effect of the ApoE4 allele and thus reduces the risk of AD.
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Duan X, Zhu W, Li Y, Zhang Z, Zhao Y, Dao J, Xiao Y. The effect of sterol regulatory element-binding protein 2 polymorphism on the serum lipid in northern Chinese subjects. J Lipid Res 2005; 46:252-7. [PMID: 15547298 DOI: 10.1194/jlr.m400166-jlr200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sterol regulatory element-binding protein 2 (SREBP-2) is an important nuclear transcription factor in the regulation of cellular cholesterol metabolism. To determine allele frequency of the 1784G>C polymorphism at the SREBP-2 locus and investigate the relationship between this polymorphism and serum lipid levels in Chinese people, we selected 486 individuals (118 men and 368 women) from the Xicheng District of Beijing. The subjects were divided into four groups: hypercholesterolemic subjects, hypertriglyceridemic subjects, combined hyperlipidemic subjects, and normal subjects. Serum lipid profiles were measured in all subjects, and 1784G>C was analyzed using polymerase chain reaction-restriction fragment length polymorphism analysis. There was no significant difference in genotype frequencies or allele frequencies of this polymorphism between the hyperlipidemic and control groups. The serum total cholesterol (TC) and LDL cholesterol (LDL-C) levels of the individuals carrying the C allele were higher than the noncarriers in both males and females in the hypercholesterolemic group, but statistical significance was only observed in females. The results of this study indicate that the SREBP-2 polymorphism is related to elevated concentrations of serum TC and LDL-C in hypercholesterolemic subjects. Further work is necessary to confirm the role of 1784G>C in the development of hyperlipidemia.
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Affiliation(s)
- Xueying Duan
- Department of Nutrition and Food Hygiene, Peking University Health Science Center, Beijing, China
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Eberlé D, Hegarty B, Bossard P, Ferré P, Foufelle F. SREBP transcription factors: master regulators of lipid homeostasis. Biochimie 2004; 86:839-48. [PMID: 15589694 DOI: 10.1016/j.biochi.2004.09.018] [Citation(s) in RCA: 1028] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Accepted: 09/27/2004] [Indexed: 02/08/2023]
Abstract
Sterol regulatory element binding proteins (SREBPs) are a family of transcription factors that regulate lipid homeostasis by controlling the expression of a range of enzymes required for endogenous cholesterol, fatty acid (FA), triacylglycerol and phospholipid synthesis. The three SREBP isoforms, SREBP-1a, SREBP-1c and SREBP-2, have different roles in lipid synthesis. In vivo studies using transgenic and knockout mice suggest that SREBP-1c is involved in FA synthesis and insulin induced glucose metabolism (particularly in lipogenesis), whereas SREBP-2 is relatively specific to cholesterol synthesis. The SREBP-1a isoform seems to be implicated in both pathways. SREBP transcription factors are synthetized as inactive precursors bound to the endoplasmic reticulum (ER) membranes. Upon activation, the precursor undergoes a sequential two-step cleavage process to release the NH(2)-terminal active domain in the nucleus (designated nSREBPs). SREBP processing is mainly controlled by cellular sterol content. When sterol levels decrease, the precursor is cleaved to activate cholesterogenic genes and maintain cholesterol homeostasis. This sterol-sensitive process appears to be a major point of regulation for the SREBP-1a and SREBP-2 isoforms but not for SREBP-1c. Moreover, the SREBP-1c isoform seems to be mainly regulated at the transcriptional level by insulin. The unique regulation and activation properties of each SREBP isoform facilitate the co-ordinate regulation of lipid metabolism; however, further studies are needed to understand the detailed regulation pathways that specifically regulate each SREBP isoform.
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Affiliation(s)
- Delphine Eberlé
- Inserm U465, Université Pierre et Marie Curie, 15, rue de l'Ecole de médecine, 75270 Paris cedex 06, France
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Manolio TA, Boerwinkle E, O'Donnell CJ, Wilson AF. Genetics of Ultrasonographic Carotid Atherosclerosis. Arterioscler Thromb Vasc Biol 2004; 24:1567-77. [PMID: 15256397 DOI: 10.1161/01.atv.0000138789.11433.c1] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The search for genes related to the cause of common complex disorders such as cardiovascular disease has been frustrating, partly because of the many factors known to contribute to cardiovascular disease and the potential "distance" of cardiovascular disease as a phenotype from genes and gene products. Linkage and association studies for phenotypes more proximal in the pathway from DNA sequence variation to overt clinical disease, such as ultrasound-defined carotid atherosclerosis, may potentially be more enlightening. Only one genetic variant previously reported to be associated with atherosclerosis or clinically evident cardiovascular disease, matrix metalloproteinase (MMP) 3, has shown consistently positive associations with carotid disease, although it has not been studied widely. Another, PON1 L55M, is weakly associated in subgroups only, and 2, ApoE and MTHFR, are equivocal. Genetic variants reported to be associated with clinical cardiovascular disease show weak or no relationship to carotid atherosclerosis. This may reflect the known inconsistency in associations of genetic variants with clinical cardiovascular disease itself. Alternatively, genetic determinants of ultrasound-defined carotid atherosclerosis may differ from those of clinically manifest cardiovascular disease and may require pursuit through large-scale genomic studies of carotid atherosclerosis as a distinct phenotype. Only 1 genetic variant, MMP 3, has shown consistently positive associations with ultrasonographic carotid disease, although it has not been studied widely. Another, PON1 L55 mol/L, is weakly associated in subgroups only. Genetic variants reported to be associated with clinical cardiovascular disease show weak or no relationship to carotid atherosclerosis.
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Affiliation(s)
- Teri A Manolio
- Division of Epidemiology and Clinical Applications, National Heart, Lung, and Blood Institute, 6701 Rockledge Drive, MSC 7934, Bethesda, MD 20892-7934, USA.
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Eberlé D, Clément K, Meyre D, Sahbatou M, Vaxillaire M, Le Gall A, Ferré P, Basdevant A, Froguel P, Foufelle F. SREBF-1 gene polymorphisms are associated with obesity and type 2 diabetes in French obese and diabetic cohorts. Diabetes 2004; 53:2153-7. [PMID: 15277400 DOI: 10.2337/diabetes.53.8.2153] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Sterol regulatory element-binding protein (SREBP)-1 transcription factors play a central role in energy homeostasis by promoting glycolysis, lipogenesis, and adipogenesis. The sterol regulatory element-binding protein gene (SREBF)-1 is a good candidate gene for obesity and obesity-related metabolic traits such as type 2 diabetes and dyslipidemia. The SREBF-1 molecular screening of 40 unrelated obese patients by PCR/single-strand conformation polymorphism revealed 19 single nucleotide polymorphisms (SNPs). Six SNPs were genotyped for an association study in large French obese and nonobese cohorts. Case-control studies using two independent nonobese cohorts indicated that SNP17 (54G/C, exon 18c) is associated with morbid obesity (odds ratio 1.5, P = 0.006 and P = 0.02, respectively). SNP3 (-150G/A, exon 1a), SNP5 (-36delG, exon 1a), and SNP17 are found in high linkage disequilibrium (D' > 0.8). The haplotype including wild-type alleles of these SNPs (C/G/G/T/C/G, HAP2) is identified as a risk factor for morbid obesity (P = 0.003). In the obese group, SNP3, SNP5, and SNP17 are associated with male-specific hypertriglyceridemia (P = 0.07, P = 0.01, and P = 0.05, respectively). SNP17 is also associated with type 2 diabetes (P = 0.03) and increased prevalence of nephropathy (P = 0.028) in a diabetic cohort. Our results indicate a role of the SREBF-1 gene in genetic predisposition of metabolic diseases such as obesity, type 2 diabetes, and dyslipidemia.
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Affiliation(s)
- Delphine Eberlé
- INSERM Unit 465, University Pierre et Marie Curie, Paris, France
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Abstract
BACKGROUND Apolipoprotein epsilon4 has been proposed as a genetic predictor for CHD. Peroxisome proliferator-activated receptors (PPAR), a recent identified nuclear transcription factor, is involved in regulation of many target genes and plays an important role in lipid metabolism, insulin sensitivity, obesity and atherosclerosis. PPARgamma gene polymorphisms may affect the profile of CHD-related risk factors. HYPOTHESIS Interaction between PPARgamma gene polymorphism and apoE polymorphisms affect the presence of CHD. METHOD This is a case-control study, which enrolled 150 cases with CHD and 157 controls without CHD. Polymerase chain reaction-restricted fragments length polymorphism was used to determine the apoE genotype and PPARgamma C161-->T substitution. RESULTS ApoE epsilon4 allele was significantly more prevalent in CHD patients than in controls (13.05 vs. 7.35%, P<0.05). The apoE epsilon4 carries had significant higher LDL-C levels than other apoE carriers and this tendency could be modified by PPARgamma CT genotype. ApoE genotype epsilon4 was an independent risk factor for CHD (OR=4.29, 95%CI: 1.6-11.48, P=0.004). A significant interaction between apoE epsilon4 and PPARgamma CT genotype was detected with respect to the effect on CHD (P=0.045). CONCLUSION This is the first study to explore the effect of interaction between PPARgamma C161-->T variant and apoE epsilon4 genotype. The result exhibited an interaction effect of two genes on serum cholesterol level. The association of CHD to apoE genotype was subjected to the attenuation effect of PPARgamma CT genotype.
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Affiliation(s)
- Dao-Quan Peng
- Department of Cardiology, The Second Xiang-Ya Hospital, Central South University, Changsha, Hunan 410011, China.
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Robinet P, Védie B, Chironi G, Gariépy J, Simon A, Moatti N, Paul JL. Characterization of polymorphic structure of SREBP-2 gene: role in atherosclerosis. Atherosclerosis 2003; 168:381-7. [PMID: 12801623 DOI: 10.1016/s0021-9150(03)00144-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sterol regulatory element binding proteins (SREBPs) are membrane-bound transcription factors that control the metabolism of cholesterol and fatty acids in mammalian cells. We postulated that polymorphisms (SNPs) in SREBP-2 gene might influence lipid parameters and the risk of coronary atherosclerosis. PCR-SSCP analysis and direct sequencing of DNA from 64 asymptomatic hypercholesterolemic men revealed seven genetic SREBP-2 SNPs. The genotype distribution of four of these SNPs (1668G>T, 1784G>C, 3474T>C and 3705C>T), and their influence on plasma lipid values and clinical parameters was studied in 655 asymptomatic men previously selected for the presence of at least one cardiovascular risk factor (hypertension, hypercholesterolemia, tobacco consumption). No significant relation was found with lipid parameters but there was a significant association between the 1784G>C polymorphism and intima-media thickness (IMT) measured in 497 subjects. Thus, a common variation in the SREBP-2 gene is related with early-stage carotid atherosclerosis in subjects with a risk of cardiovascular events without detectable change in plasma lipid levels.
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Affiliation(s)
- Peggy Robinet
- Laboratoire de Biochimie Appliquée, UFR de pharmacie, Châtenay-Malabry, France
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Rios DLS, Vargas AF, Torres MR, Zago AJ, Callegari-Jacques SM, Hutz MH. Interaction between SREBP-1a and APOB polymorphisms influences total and low-density lipoprotein cholesterol levels in patients with coronary artery disease. Clin Genet 2003; 63:380-5. [PMID: 12752570 DOI: 10.1034/j.1399-0004.2003.00057.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this study, we examined the insertion/deletion (Ins/Del) and XbaI polymorphisms of the apolipoprotein B (APOB) gene and the -36delG polymorphism in the sterol regulatory element binding protein-1a (SREBP-1a) gene in 298 patients with non-diabetic angiographically assessed coronary artery disease (CAD), and 188 healthy controls, from a Brazilian population of European descent. Del/X+ haplotype carriers had higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in patients (TC, p = 0.05; LDL-C, p = 0.049) and controls (TC, p = 0.004; LDL-C, p = 0.013). No association was detected between the SREBP-1a-36delG polymorphism and lipid levels, but a significant interaction effect between APOB and SREBP-1a polymorphisms was observed in the patient sample on TC (p = 0.005) and on LDL-C (p = 0.019) levels. Carriers of the APOB Del/X+ haplotype and SREBP-1a G-G- genotype showed the highest levels of these lipid parameters. This effect of interaction was not observed in the control sample. Despite the associations with lipids, these polymorphisms were not associated with CAD risk or severity in this sample.
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Affiliation(s)
- D L S Rios
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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Salek L, Lutucuta S, Ballantyne CM, Gotto AM, Marian AJ. Effects of SREBF-1a and SCAP polymorphisms on plasma levels of lipids, severity, progression and regression of coronary atherosclerosis and response to therapy with fluvastatin. J Mol Med (Berl) 2002; 80:737-44. [PMID: 12436350 PMCID: PMC2896566 DOI: 10.1007/s00109-002-0381-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2002] [Accepted: 07/25/2002] [Indexed: 10/27/2022]
Abstract
Sterol regulatory elements binding factor-1a (SREBF-1a) and SREBF cleavage activating protein (SCAP) regulate lipids homeostasis. Polymorphisms in SREBF-1a and SCAP could affect plasma levels of lipids and risk of atherosclerosis. We determined association of SREBF-1a -36del/G and SCAP 2386A/G genotypes with plasma levels of lipids, severity and progression/regression of coronary atherosclerosis, and response to treatment with fluvastatin in a well-characterized Lipoprotein Coronary Atherosclerosis Study population. Plasma lipids and quantitative indices of coronary atherosclerosis were obtained at baseline and 2.5 years following randomization to fluvastatin or placebo in 372 subjects. Fluvastatin reduced plasma levels of total cholesterol by 16%, LDL-C by 25%, and ApoB by 16% and increased plasma levels of HDL-C by 9% and apoA-1 by 7%. Distributions of SREBF-1a SCAP genotypes were 60 GG, 172 del-G and 140 del-del and 88 GG, 188 GA and 96 AA, respectively. There were no significant differences in baseline plasma levels of lipids or indices of severity of atherosclerosis among the genotypes of each gene. There was a strong graded genotype-treatment interaction between SREBF-1a genotypes and change in apoA-I levels in response to fluvastatin (16.5% increase in GG, 10.5% in del/G, and 0.4% in del/del groups). Modest interactions between SREBF-1a genotypes and changes in HDL-C, and apoC-III levels in response to fluvastatin were also present. No genotype-treatment interaction for progression or regression of coronary atherosclerosis was detected. There were no significant interactions between SCAP genotypes and response to therapy. Thus we detected a strong graded interaction between SREBF-1a -36del/G genotypes and response of plasma apoA-I to treatment with fluvastatin.
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Affiliation(s)
- Lorraine Salek
- Section of Cardiology, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Drunat S, Moatti N, Demuth K. Homocysteine decreases endothelin-1 expression by interfering with the AP-1 signaling pathway. Free Radic Biol Med 2002; 33:659-68. [PMID: 12208352 DOI: 10.1016/s0891-5849(02)00957-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The increased cardiovascular risk associated with hyperhomocysteinemia has been linked to homocysteine-induced endothelial cell (EC) dysfunction. Endothelin-1 is a vasoactive peptide, synthesized mainly by vascular ECs. We have previously shown that homocysteine decreases endothelin-1 biosynthesis. Here we addressed the molecular mechanism of endothelin-1 regulation by homocysteine. Experiments with the transcription inhibitor actinomycin D indicated that the decrease in preproendothelin-1 mRNA content in homocysteine-treated cells did not result from transcript destabilization. Transient transfection assays demonstrated that homocysteine downregulated endothelin-1 at the transcriptional level by decreasing preproendothelin-1 promoter activity. Mutation of the activator protein-1 (AP-1) site of the promoter eliminated the repression induced by homocysteine. Western blot analysis showed that the homocysteine-induced decrease in promoter activity was not associated with reduced expression of the AP-1 components c-Fos and c-Jun. The inhibitory action of homocysteine on preproendothelin-1 mRNA expression was not prevented by cycloheximide. Electrophoretic mobility shift assays demonstrated that homocysteine reduced the binding activity of ECs nuclear extracts to an AP-1 consensus site. These results indicate that homocysteine downregulates endothelin-1 synthesis by inhibiting AP-1 activity, and that the AP-1 signaling pathway may be of major importance in homocysteine-induced endothelial dysfunction.
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Affiliation(s)
- Séverine Drunat
- Laboratoire de Biochimie Appliquée and IFR ISIT, Faculté de Pharmacie, Université Paris XI, Chatenay-Malabry, France
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