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Gu R, Wang H, Wang CL, Lu M, Miao M, Huang MN, Chen Y, Dai YL, Zhu MQ, Zhou Q, Zou CC. Gene variants and clinical characteristics of children with sitosterolemia. Lipids Health Dis 2024; 23:83. [PMID: 38509578 PMCID: PMC10953262 DOI: 10.1186/s12944-024-02077-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/12/2024] [Indexed: 03/22/2024] Open
Abstract
OBJECTIVE To enhance the detection, management and monitoring of Chinese children afflicted with sitosterolemia by examining the physical characteristics and genetic makeup of pediatric patients. METHODS In this group, 26 children were diagnosed with sitosterolemia, 24 of whom underwent genetic analysis. Patient family medical history, physical symptoms, tests for liver function, lipid levels, standard blood tests, phytosterol levels, cardiac/carotid artery ultrasounds, fundus examinations, and treatment were collected. RESULTS The majority (19, 73.1%) of the 26 patients exhibited xanthomas as the most prevalent manifestation. The second most common symptoms were joint pain (7, 26.9%) and stunted growth (4, 15.4%). Among the 24 (92.3%) patients whose genetics were analyzed, 16 (66.7%) harbored ABCG5 variants (type 2 sitosterolemia), and nearly one-third (8, 33.3%) harbored ABCG8 variants (type 1 sitosterolemia). Additionally, the most common pathogenic ABCG5 variant was c.1166G > A (p.Arg389His), which was found in 10 patients (66.7%). Further analysis did not indicate any significant differences in pathological traits among those carrying ABCG5 and ABCG8 variations (P > 0.05). Interestingly, there was a greater abundance of nonsense variations in ABCG5 than in ABCG8 (P = 0.09), and a greater frequency of splicing variations in ABCG8 than ABCG5 (P = 0.01). Following a change in diet or a combination of ezetimibe, the levels of cholesterol and low-density lipoprotein were markedly decreased compared to the levels reported before treatment. CONCLUSION Sitosterolemia should be considered for individuals presenting with xanthomas and increased cholesterol levels. Phytosterol testing and genetic analysis are important for early detection. Managing one's diet and taking ezetimibe can well control blood lipids.
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Affiliation(s)
- Rui Gu
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
- Department of NICU, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Hui Wang
- Department of Rehabilitation, Children's Hospital of Zhejiang University School of Medicine, Zhejiang, China
| | - Chun-Lin Wang
- Department of Pediatrics, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Mei Lu
- Department of Pediatrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Miao Miao
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Meng-Na Huang
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Yi Chen
- Department of Pulmonology, Children's Hospital of Zhejiang University School of Medicine, Zhejiang, Hangzhou, China
| | - Yang-Li Dai
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Ming-Qiang Zhu
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Qiong Zhou
- Department of Pediatrics, Hangzhou Children's Hospital, Hangzhou, 310005, China
| | - Chao-Chun Zou
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China.
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Terasaki M, Izumi M, Yamagishi SI. A Clinical Case of Probable Sitosterolemia. Int J Mol Sci 2024; 25:1535. [PMID: 38338819 PMCID: PMC10855567 DOI: 10.3390/ijms25031535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Sitosterolemia is a rare genetic lipid disorder characterized by elevated plant sterols in the serum. A 24-year-old Japanese woman was referred to our hospital due to a high serum low-density lipoprotein cholesterol (LDL-C) level of 332 mg/dL. At first, she was suspected to suffer from familial hypercholesterolemia, and thus received lipid-lowering agents. Although her LDL-C level remained high (220 mg/dL) with diet therapy plus 10 mg/day rosuvastatin, it was drastically decreased to 46 mg/dL with the addition of 10 mg/day ezetimibe. Finally, her LDL-C level was well-controlled at about 70 mg/dL with 10 mg/day ezetimibe alone. Furthermore, while her serum sitosterol level was elevated at 10.5 μg/mL during the first visit to our hospital, it decreased to 3.6 μg/mL with the 10 mg/day ezetimibe treatment alone. These observations suggest that she might probably suffer from sitosterolemia. Therefore, targeted gene sequencing analysis was performed using custom panels focusing on the exome regions of 21 lipid-associated genes, including ABCG5, ABCG8, and familial hypercholesterolemia-causing genes (LDL receptor, LDLRAP1, PCSK9, and apolipoprotein B). We finally identified a heterozygous ABCG8 variant (NM_022437.2:c.1285A>G or NP_071882.1:p.Met429Val) in our patient. The same gene mutation was detected in her mother. We report here a rare case exhibiting probable sitosterolemia caused by a heterozygous Met429Val variant in the ABCG8 gene and additional unknown variants.
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Affiliation(s)
- Michishige Terasaki
- Division of Diabetes, Metabolism and Endocrinology, Showa University Graduate School of Medicine, 1-5-8 Shinagawa, Tokyo 142-8666, Japan;
| | - Mikiko Izumi
- Center for Clinical Genetics, Showa University Hospital, 1-5-8 Shinagawa, Tokyo 142-8666, Japan;
| | - Sho-ichi Yamagishi
- Division of Diabetes, Metabolism and Endocrinology, Showa University Graduate School of Medicine, 1-5-8 Shinagawa, Tokyo 142-8666, Japan;
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Zhao ZY, Li JY, Huang WH, Qiu LL, Qian BH, Zha ZS. [Child with sitosterolemia initially presenting with hemolytic anemia and thrombocytopenia: a case repore and literrature review]. Zhonghua Xue Ye Xue Za Zhi 2024; 45:90-93. [PMID: 38527845 DOI: 10.3760/cma.j.cn121090-20230915-0068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
This article focuses on a case study of sitosterolemia in a child who initially presented with hemolytic anemia and thrombocytopenia. Sitosterolemia is a rare autosomal recessive lipid metabolism disorder, difficult to diagnose due to its non-typical clinical manifestations. The 8-year-old patient was initially misdiagnosed with pyruvate kinase deficiency. Comprehensive biochemical and molecular biology analyses, including gene sequencing, eventually led to the correct diagnosis of sitosterolemia. This case highlights the complexity and diagnostic challenges of sitosterolemia, emphasizing the need for increased awareness and accurate diagnosis in patients presenting with similar symptoms.
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Affiliation(s)
- Z Y Zhao
- Department of Blood Transfusion, Changhai Hospital, The First Affiliated Hospital of PLA Naval Medical University, Research &Innovation Base of Pediatric Hemolytic Anemia, Shanghai 200433, China
| | - J Y Li
- Department of Blood Transfusion, Changhai Hospital, The First Affiliated Hospital of PLA Naval Medical University, Research &Innovation Base of Pediatric Hemolytic Anemia, Shanghai 200433, China
| | - W H Huang
- Department of Blood Transfusion, Changhai Hospital, The First Affiliated Hospital of PLA Naval Medical University, Research &Innovation Base of Pediatric Hemolytic Anemia, Shanghai 200433, China
| | - L L Qiu
- Department of Blood Transfusion, Changhai Hospital, The First Affiliated Hospital of PLA Naval Medical University, Research &Innovation Base of Pediatric Hemolytic Anemia, Shanghai 200433, China
| | - B H Qian
- Department of Blood Transfusion, Changhai Hospital, The First Affiliated Hospital of PLA Naval Medical University, Research &Innovation Base of Pediatric Hemolytic Anemia, Shanghai 200433, China
| | - Z S Zha
- Department of Blood Transfusion, Changhai Hospital, The First Affiliated Hospital of PLA Naval Medical University, Research &Innovation Base of Pediatric Hemolytic Anemia, Shanghai 200433, China
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Bydlowski SP, Levy D. Association of ABCG5 and ABCG8 Transporters with Sitosterolemia. Adv Exp Med Biol 2024; 1440:31-42. [PMID: 38036873 DOI: 10.1007/978-3-031-43883-7_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Sitosterolemia is a rare genetic lipid disorder, mainly characterized by the accumulation of dietary xenosterols in plasma and tissues. It is caused by inactivating mutations in either ABCG5 or ABCG8 subunits, a subfamily-G ATP-binding cassette (ABCG) transporters. ABCG5/G8 encodes a pair of ABC half transporters that form a heterodimer (G5G8). This heterodimeric ATP-binding cassette (ABC) sterol transporter, ABCG5/G8, is responsible for the hepatobiliary and transintestinal secretion of cholesterol and dietary plant sterols to the surface of hepatocytes and enterocytes, promoting the secretion of cholesterol and xenosterols into the bile and the intestinal lumen. In this way, ABCG5/G8 function in the reverse cholesterol transport pathway and mediate the efflux of cholesterol and xenosterols to high-density lipoprotein and bile salt micelles, respectively. Here, we review the biological characteristics and function of ABCG5/G8, and how the mutations of ABCG5/G8 can cause sitosterolemia, a loss-of-function disorder characterized by plant sterol accumulation and premature atherosclerosis, among other features.
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Affiliation(s)
- Sergio Paulo Bydlowski
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo, Brazil.
- National Institute of Science and Technology in Regenerative Medicine (INCT-Regenera) CNPq, Rio de Janeiro, Brazil.
| | - Debora Levy
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), Heart Institute (InCor), Faculdade de Medicina, Universidade de São Paulo, Sao Paulo, Brazil
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Jiang W, Xu Y, Fu Z, Hu M, Wu Q, Ji Y, Li JZ, Gong Y, Zhou H. Genetic analysis and functional study of a novel ABCG5 mutation in sitosterolemia with hematologic disease. Gene 2023; 879:147596. [PMID: 37390873 DOI: 10.1016/j.gene.2023.147596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/24/2023] [Accepted: 06/27/2023] [Indexed: 07/02/2023]
Abstract
Sitosterolemia is a rare autosomal recessive hereditary disease caused by loss-of-function genetic mutations in either ATP-binding cassette subfamily G member 5 or member 8 (ABCG5 or ABCG8). Here, we investigate novel variants in ABCG5 and ABCG8 that are associated with the sitosterolemia phenotype. We describe a 32-year-old woman with hypercholesterolemia, tendon and hip xanthomas, autoimmune hemolytic anemia and macrothrombocytopenia from early life, which make us highly suspicious of the possibility of sitosterolemia. A novel homozygous variant in ABCG5 (c.1769C>A, p.S590X) was identified by genomic sequencing. We also examined the lipid profile, especially plant sterols levels, using gas chromatography-mass spectrometry. Functional studies, including western blotting and immunofluorescence staining, showed that the nonsense mutation ABCG5 1769C>A hinders the formation of ABCG5 and ABCG8 heterodimers and the function of transporting sterols. Our study expands the knowledge of variants in sitosterolemia and provides diagnosis and treatment recommendations.
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Affiliation(s)
- Wanzi Jiang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Yiwen Xu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Zhenzhen Fu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Moran Hu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Qinyi Wu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Yong Ji
- Key Laboratory of Cardiovascular and Cerebrovascular Medicine, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Suzhou, China
| | - John Zhong Li
- The Key Laboratory of Rare Metabolic Disease, Department of Biochemistry and Molecular Biology, The Key Laboratory of Human Functional Genomics of Jiangsu Province, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, China
| | - Yingyun Gong
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China.
| | - Hongwen Zhou
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China.
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Abstract
PURPOSE OF REVIEW The purpose of this review was to summarize important and updated information on sitosterolemia. Sitosterolemia is an inherited lipid disorder consisting of high levels of plasma plant sterols. This sterol storage condition is caused by biallelic loss-of-function genetic variants in either ABCG5 or ABCG8, leading to increased intestinal absorption and decreased hepatic excretion of plant sterols. Clinically, patients with sitosterolemia usually exhibit xanthomatosis, high levels of plasma cholesterol, and premature atherosclerotic disease, but presentation can be highly heterogeneous. Therefore, recognition of this condition requires a high level of suspicion, with confirmation upon genetic diagnosis or through measurement of plasma phytosterols. Treatment of sitosterolemia with both a plant sterol-restricted diet and the intestinal cholesterol absorption inhibitor ezetimibe can reduce efficiently the levels of plasma plant sterols, consisting in the first-line therapy for this disease. RECENT FINDINGS Since hypercholesterolemia is often present in individuals with sitosterolemia, it is important to search for genetic variants in ABCG5 and ABCG8 in patients with clinical criteria for familial hypercholesterolemia (FH), but no variants in FH implicated genes. Indeed, recent studies have suggested that genetic variants in ABCG5/ABCG8 can mimic FH, and even when in heterozygosis, they may potentially exacerbate the phenotype of patients with severe dyslipidemia. Sitosterolemia is a genetic lipid disorder characterized by increased circulating levels of plant sterols and clinically manifested by xanthomatosis, hematologic disorders, and early atherosclerosis. Awareness about this condition, a rare, but commonly underdiagnosed and yet treatable cause of premature atherosclerotic disease, is imperative.
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Affiliation(s)
- Viviane Zorzanelli Rocha
- Lipid Clinic, Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil.
- Fleury Medicina E Saúde, São Paulo, SP, Brazil.
| | - Mauricio Teruo Tada
- Laboratory of Genetics and Molecular Cardiology (LIM13), Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil
| | - Ana Paula Marte Chacra
- Lipid Clinic, Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil
| | - Marcio Hiroshi Miname
- Lipid Clinic, Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil
| | - Marjorie H Mizuta
- Lipid Clinic, Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil
- Laboratory of Genetics and Molecular Cardiology (LIM13), Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil
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Xia Y, Duan Y, Zheng W, Liang L, Zhang H, Luo X, Gu X, Sun Y, Xiao B, Qiu W. Clinical, genetic profile and therapy evaluation of 55 children and 5 adults with sitosterolemia. J Clin Lipidol 2021; 16:40-51. [PMID: 34969652 DOI: 10.1016/j.jacl.2021.11.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/03/2021] [Accepted: 11/29/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Sitosterolemia is a rare autosomal recessive disease characterized by phytosterol accumulation in the blood and tissues. However, the detailed clinical and genetic spectra are lacking. OBJECTIVE To describe and compare the clinical, biochemical, genetic, therapeutic, and follow-up characteristics of 55 pediatric and five adult sitosterolemia patients. METHODS Clinical, genetic and therapeutic data from 60 patients at Xinhua Hospital from January 2016 to June 2021 were retrospectively collected. RESULTS Pediatric patients' manifestations included xanthomas(93%), hematological disorders(30%), arthralgia(24%), splenomegaly(11%), atherosclerosis(10%). Adult patients had symptoms such as atherosclerosis(5/5), xanthomas(4/5), hematological disorders(3/5), arthralgia(3/5), splenomegaly(3/5). Elevated total cholesterol(TC) and low-density lipoprotein cholesterol(LDL-C) were observed in 96% patients (pediatric 98%, adult 3/4), and phytosterol levels in 100% patients. The age of onset was also negatively correlated with blood TC (P < 0.0001, r = -0.5548) and LDL-C (P = 0.0001, r = -0.4859) levels. Targeted treatments resulted in symptomatic remission(pediatric 96%, adult 4/5), and significantly decreased lipid and phytosterol levels(all P<0.05). In the dietary-therapy cohort(n=34), blood lipid levels decreased(all P<0.05). In the 13 pediatric patients from the dietary-therapy cohort who switched from dietary to combination therapy with ezetimibe, dietary therapy decreased TC and LDL-C levels by 54% and 52%, and ezetimibe further decreased them by 18% and 20%, respectively. Further, we identified 15 novel ABCG5/ABCG8 variants. CONCLUSIONS This study expands the clinical and genetic spectra of sitosterolemia. The low-phytosterol diet is the cornerstone of sitosterolemia treatment. Ezetimibe can further decrease blood lipid levels and increase daily dietary phytosterol tolerance.
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Affiliation(s)
- Yu Xia
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Ying Duan
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Wanqi Zheng
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Lili Liang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Huiwen Zhang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Xiaomei Luo
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Yu Sun
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China.
| | - Bing Xiao
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China.
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China.
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Williams K, Segard A, Graf GA. Sitosterolemia: Twenty Years of Discovery of the Function of ABCG5ABCG8. Int J Mol Sci 2021; 22:2641. [PMID: 33807969 PMCID: PMC7961684 DOI: 10.3390/ijms22052641] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/19/2021] [Accepted: 02/26/2021] [Indexed: 02/06/2023] Open
Abstract
Sitosterolemia is a lipid disorder characterized by the accumulation of dietary xenosterols in plasma and tissues caused by mutations in either ABCG5 or ABCG8. ABCG5 ABCG8 encodes a pair of ABC half transporters that form a heterodimer (G5G8), which then traffics to the surface of hepatocytes and enterocytes and promotes the secretion of cholesterol and xenosterols into the bile and the intestinal lumen. We review the literature from the initial description of the disease, the discovery of its genetic basis, current therapy, and what has been learned from animal, cellular, and molecular investigations of the transporter in the twenty years since its discovery. The genomic era has revealed that there are far more carriers of loss of function mutations and likely pathogenic variants of ABCG5 ABCG8 than previously thought. The impact of these variants on G5G8 structure and activity are largely unknown. We propose a classification system for ABCG5 ABCG8 mutants based on previously published systems for diseases caused by defects in ABC transporters. This system establishes a framework for the comprehensive analysis of disease-associated variants and their impact on G5G8 structure-function.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily G, Member 5/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 5/history
- ATP Binding Cassette Transporter, Subfamily G, Member 5/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 8/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 8/history
- ATP Binding Cassette Transporter, Subfamily G, Member 8/metabolism
- Animals
- Cholesterol/metabolism
- Enterocytes/metabolism
- Enterocytes/pathology
- Hepatocytes/metabolism
- Hepatocytes/pathology
- History, 21st Century
- Humans
- Hypercholesterolemia/genetics
- Hypercholesterolemia/history
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Intestinal Diseases/genetics
- Intestinal Diseases/history
- Intestinal Diseases/metabolism
- Intestinal Diseases/pathology
- Lipid Metabolism, Inborn Errors/genetics
- Lipid Metabolism, Inborn Errors/history
- Lipid Metabolism, Inborn Errors/metabolism
- Lipid Metabolism, Inborn Errors/pathology
- Lipoproteins/genetics
- Lipoproteins/history
- Lipoproteins/metabolism
- Mutation
- Phytosterols/adverse effects
- Phytosterols/genetics
- Phytosterols/history
- Phytosterols/metabolism
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Affiliation(s)
- Kori Williams
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; (K.W.); (A.S.)
| | - Allison Segard
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; (K.W.); (A.S.)
| | - Gregory A. Graf
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; (K.W.); (A.S.)
- Saha Cardiovascular Research Center, Lexington, KY 40536, USA
- Barnstable Brown Diabetes and Obesity Center, Lexington, KY 40536, USA
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Shtratnikova VY, Sсhelkunov MI, Fokina VV, Bragin EY, Shutov AA, Donova MV. Different genome-wide transcriptome responses of Nocardioides simplex VKM Ac-2033D to phytosterol and cortisone 21-acetate. BMC Biotechnol 2021; 21:7. [PMID: 33441120 PMCID: PMC7807495 DOI: 10.1186/s12896-021-00668-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/14/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bacterial degradation/transformation of steroids is widely investigated to create biotechnologically relevant strains for industrial application. The strain of Nocardioides simplex VKM Ac-2033D is well known mainly for its superior 3-ketosteroid Δ1-dehydrogenase activity towards various 3-oxosteroids and other important reactions of sterol degradation. However, its biocatalytic capacities and the molecular fundamentals of its activity towards natural sterols and synthetic steroids were not fully understood. In this study, a comparative investigation of the genome-wide transcriptome profiling of the N. simplex VKM Ac-2033D grown on phytosterol, or in the presence of cortisone 21-acetate was performed with RNA-seq. RESULTS Although the gene patterns induced by phytosterol generally resemble the gene sets involved in phytosterol degradation pathways in mycolic acid rich actinobacteria such as Mycolicibacterium, Mycobacterium and Rhodococcus species, the differences in gene organization and previously unreported genes with high expression level were revealed. Transcription of the genes related to KstR- and KstR2-regulons was mainly enhanced in response to phytosterol, and the role in steroid catabolism is predicted for some dozens of the genes in N. simplex. New transcription factors binding motifs and new candidate transcription regulators of steroid catabolism were predicted in N. simplex. Unlike phytosterol, cortisone 21-acetate does not provide induction of the genes with predicted KstR and KstR2 sites. Superior 3-ketosteroid-Δ1-dehydrogenase activity of N. simplex VKM Ac-2033D is due to the kstDs redundancy in the genome, with the highest expression level of the gene KR76_27125 orthologous to kstD2, in response to cortisone 21-acetate. The substrate spectrum of N. simplex 3-ketosteroid-Δ1-dehydrogenase was expanded in this study with progesterone and its 17α-hydroxylated and 11α,17α-dihydroxylated derivatives, that effectively were 1(2)-dehydrogenated in vivo by the whole cells of the N. simplex VKM Ac-2033D. CONCLUSION The results contribute to the knowledge of biocatalytic features and diversity of steroid modification capabilities of actinobacteria, defining targets for further bioengineering manipulations with the purpose of expansion of their biotechnological applications.
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Affiliation(s)
- Victoria Yu Shtratnikova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie gory, h. 1, b. 40, Moscow, Russian Federation 119991
| | - Mikhail I. Sсhelkunov
- Skolkovo Institute of Science and Technology, Nobelya str., 3, Moscow, Russian Federation 121205
- Institute for Information Transmission Problems, Russian Academy of Sciences, Bolshoy Karetny per., h. 19, b. 1, Moscow, Russian Federation 127994
| | - Victoria V. Fokina
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Center for Biological Research of the Russian Academy of Sciences”, pr. Nauki, 5, Pushchino, Moscow Region, Russian Federation 142290
- Pharmins, Ltd., R&D, Institutskaya str, 4, Pushchino, Moscow Region, Russian Federation 142290
| | - Eugeny Y. Bragin
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Center for Biological Research of the Russian Academy of Sciences”, pr. Nauki, 5, Pushchino, Moscow Region, Russian Federation 142290
| | - Andrey A. Shutov
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Center for Biological Research of the Russian Academy of Sciences”, pr. Nauki, 5, Pushchino, Moscow Region, Russian Federation 142290
- Pharmins, Ltd., R&D, Institutskaya str, 4, Pushchino, Moscow Region, Russian Federation 142290
| | - Marina V. Donova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Center for Biological Research of the Russian Academy of Sciences”, pr. Nauki, 5, Pushchino, Moscow Region, Russian Federation 142290
- Pharmins, Ltd., R&D, Institutskaya str, 4, Pushchino, Moscow Region, Russian Federation 142290
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10
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Tanaka H, Watanabe Y, Hirano S, Tada H, Nomura A, Kawashiri MA, Takenaga M. Sitosterolemia Exhibiting Severe Hypercholesterolemia with Tendon Xanthomas Due to Compound Heterozygous ABCG5 Gene Mutations Treated with Ezetimibe and Alirocumab. Intern Med 2020; 59:3033-3037. [PMID: 32713907 PMCID: PMC7759703 DOI: 10.2169/internalmedicine.3811-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We herein report a rare case presenting with severe hypercholesterolemia, massive Achilles tendon xanthomas, and multi-vessel coronary artery disease. Initially, the patient was misdiagnosed with familial hypercholesterolemia. However, a genetic analysis using our custom sequencing panel covering genes associated with Mendelian lipid disorders revealed him to have a genetic basis of sitosterolemia with compound heterozygous mutations in the adenosine triphosphate binding cassette subfamily G5 (ABCG5) gene. A comprehensive genetic analysis can be particularly useful for diagnosing cases with severe phenotypes, leading to appropriate and medical therapies. Our patient was refractory to statins, whereas ezetimibe and PCSK9 inhibitor with a low-plant-sterol diet successfully reduced his serum levels of low-density lipoprotein cholesterol.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily G, Member 5/genetics
- Achilles Tendon/physiopathology
- Antibodies, Monoclonal, Humanized/therapeutic use
- Anticholesteremic Agents/therapeutic use
- Cholesterol, LDL/blood
- Cholesterol, LDL/drug effects
- Ezetimibe/therapeutic use
- Humans
- Hypercholesterolemia/complications
- Hypercholesterolemia/diagnosis
- Hypercholesterolemia/drug therapy
- Hypercholesterolemia/etiology
- Hypercholesterolemia/genetics
- Intestinal Diseases/complications
- Intestinal Diseases/diagnosis
- Intestinal Diseases/drug therapy
- Intestinal Diseases/genetics
- Lipid Metabolism, Inborn Errors/complications
- Lipid Metabolism, Inborn Errors/diagnosis
- Lipid Metabolism, Inborn Errors/drug therapy
- Lipid Metabolism, Inborn Errors/genetics
- Male
- Middle Aged
- Mutation
- Phytosterols/adverse effects
- Phytosterols/genetics
- Treatment Outcome
- Xanthomatosis/drug therapy
- Xanthomatosis/etiology
- Xanthomatosis/physiopathology
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Affiliation(s)
- Hiroki Tanaka
- Department of Cardiovascular Medicine, Fujimoto Central Hospital, Japan
| | - Yuki Watanabe
- Department of Cardiovascular Medicine, Fujimoto Central Hospital, Japan
| | - Shuji Hirano
- Department of Cardiovascular Medicine, Fujimoto Central Hospital, Japan
| | - Hayato Tada
- Department of Cardiology, Kanazawa University Graduate School of Medicine, Japan
| | - Akihiro Nomura
- Department of Cardiology, Kanazawa University Graduate School of Medicine, Japan
| | - Masa-Aki Kawashiri
- Department of Cardiology, Kanazawa University Graduate School of Medicine, Japan
| | - Makoto Takenaga
- Department of Cardiovascular Medicine, Fujimoto Central Hospital, Japan
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11
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Nakano Y, Komiya C, Shimizu H, Mishima H, Shiba K, Tsujimoto K, Ikeda K, Kashimada K, Dateki S, Yoshiura KI, Ogawa Y, Yamada T. A case of ezetimibe-effective hypercholesterolemia with a novel heterozygous variant in ABCG5. Endocr J 2020; 67:1099-1105. [PMID: 32641618 DOI: 10.1507/endocrj.ej20-0044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Sitosterolemia is caused by homozygous or compound heterozygous gene mutations in either ATP-binding cassette subfamily G member 5 (ABCG5) or 8 (ABCG8). Since ABCG5 and ABCG8 play pivotal roles in the excretion of neutral sterols into feces and bile, patients with sitosterolemia present elevated levels of serum plant sterols and in some cases also hypercholesterolemia. A 48-year-old woman was referred to our hospital for hypercholesterolemia. She had been misdiagnosed with familial hypercholesterolemia at the age of 20 and her serum low-density lipoprotein cholesterol (LDL-C) levels had remained about 200-300 mg/dL at the former clinic. Although the treatment of hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors was ineffective, her serum LDL-C levels were normalized by ezetimibe, a cholesterol transporter inhibitor. We noticed that her serum sitosterol and campesterol levels were relatively high. Targeted analysis sequencing identified a novel heterozygous ABCG5 variant (c.203A>T; p.Ile68Asn) in the patient, whereas no mutations were found in low-density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type 9 (PCSK9), or Niemann-Pick C1-like intracellular cholesterol transporter 1 (NPC1L1). While sitosterolemia is a rare disease, a recent study has reported that the incidence of loss-of-function mutation in the ABCG5 or ABCG8 gene is higher than we thought at 1 in 220 individuals. The present case suggests that serum plant sterol levels should be examined and ezetimibe treatment should be considered in patients with hypercholesterolemia who are resistant to HMG-CoA reductase inhibitors.
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Affiliation(s)
- Yujiro Nakano
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Chikara Komiya
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Hitomi Shimizu
- Department of Pediatrics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaski 852-8501, Japan
- Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Hiroyuki Mishima
- Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Kumiko Shiba
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Kazutaka Tsujimoto
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Kenji Ikeda
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Kenichi Kashimada
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Sumito Dateki
- Department of Pediatrics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaski 852-8501, Japan
| | - Koh-Ichiro Yoshiura
- Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan
| | - Yoshihiro Ogawa
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tetsuya Yamada
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
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12
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Xavier BM, Zein AA, Venes A, Wang J, Lee JY. Transmembrane Polar Relay Drives the Allosteric Regulation for ABCG5/G8 Sterol Transporter. Int J Mol Sci 2020; 21:ijms21228747. [PMID: 33228147 PMCID: PMC7699580 DOI: 10.3390/ijms21228747] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 12/16/2022] Open
Abstract
The heterodimeric ATP-binding cassette (ABC) sterol transporter, ABCG5/G8, is responsible for the biliary and transintestinal secretion of cholesterol and dietary plant sterols. Missense mutations of ABCG5/G8 can cause sitosterolemia, a loss-of-function disorder characterized by plant sterol accumulation and premature atherosclerosis. A new molecular framework was recently established by a crystal structure of human ABCG5/G8 and reveals a network of polar and charged amino acids in the core of the transmembrane domains, namely, a polar relay. In this study, we utilize genetic variants to dissect the mechanistic role of this transmembrane polar relay in controlling ABCG5/G8 function. We demonstrated a sterol-coupled ATPase activity of ABCG5/G8 by cholesteryl hemisuccinate (CHS), a relatively water-soluble cholesterol memetic, and characterized CHS-coupled ATPase activity of three loss-of-function missense variants, R543S, E146Q, and A540F, which are respectively within, in contact with, and distant from the polar relay. The results established an in vitro phenotype of the loss-of-function and missense mutations of ABCG5/G8, showing significantly impaired ATPase activity and loss of energy sufficient to weaken the signal transmission from the transmembrane domains. Our data provide a biochemical evidence underlying the importance of the polar relay and its network in regulating the catalytic activity of ABCG5/G8 sterol transporter.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily G, Member 5/chemistry
- ATP Binding Cassette Transporter, Subfamily G, Member 5/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 5/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 8/chemistry
- ATP Binding Cassette Transporter, Subfamily G, Member 8/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 8/metabolism
- Adenosine Triphosphatases/chemistry
- Adenosine Triphosphatases/genetics
- Adenosine Triphosphatases/metabolism
- Adenosine Triphosphate/chemistry
- Adenosine Triphosphate/metabolism
- Allosteric Regulation
- Binding Sites
- Biological Transport
- Cholesterol/chemistry
- Cholesterol/metabolism
- Cholesterol Esters/chemistry
- Cholesterol Esters/metabolism
- Cholic Acid/chemistry
- Cholic Acid/metabolism
- Gene Expression
- Humans
- Hypercholesterolemia/genetics
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Intestinal Diseases/genetics
- Intestinal Diseases/metabolism
- Intestinal Diseases/pathology
- Kinetics
- Lipid Metabolism, Inborn Errors/genetics
- Lipid Metabolism, Inborn Errors/metabolism
- Lipid Metabolism, Inborn Errors/pathology
- Lipoproteins/chemistry
- Lipoproteins/genetics
- Lipoproteins/metabolism
- Models, Molecular
- Mutation
- Phytosterols/adverse effects
- Phytosterols/genetics
- Phytosterols/metabolism
- Pichia/chemistry
- Pichia/genetics
- Pichia/metabolism
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Thermodynamics
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Affiliation(s)
- Bala M. Xavier
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (B.M.X.); (A.A.Z.); (A.V.)
| | - Aiman A. Zein
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (B.M.X.); (A.A.Z.); (A.V.)
| | - Angelica Venes
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (B.M.X.); (A.A.Z.); (A.V.)
- Biomedical Sciences Program, Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Junmei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15206, USA
- Correspondence: (J.W.); (J.-Y.L.); Tel.: +1-412-383-3268 (J.W.); +1-613-562-5800 (ext. 8308) (J.-Y.L.)
| | - Jyh-Yeuan Lee
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (B.M.X.); (A.A.Z.); (A.V.)
- Correspondence: (J.W.); (J.-Y.L.); Tel.: +1-412-383-3268 (J.W.); +1-613-562-5800 (ext. 8308) (J.-Y.L.)
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13
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Lee JH, Song DY, Jun SH, Song SH, Shin CH, Ki CS, Lee K, Song J. High prevalence of increased sitosterol levels in hypercholesterolemic children suggest underestimation of sitosterolemia incidence. PLoS One 2020; 15:e0238079. [PMID: 32845916 PMCID: PMC7449458 DOI: 10.1371/journal.pone.0238079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/10/2020] [Indexed: 01/26/2023] Open
Abstract
Background Sitosterolemia is an inherited lipid disorder which presents with elevated serum sitosterol and can result in an increased risk of premature cardiovascular disease. However, sitosterol cannot be accurately measured by routine diagnostic assays, meaning that sitosterolemia diagnosis can often be difficult, especially with many clinical features overlapping with familial hypercholesterolemia. With such complications resulting in increasing reports of misdiagnosis, the prevalence of sitosterolemia is predicted to be much higher than previously reported. Methods Gas chromatography-mass spectrometry was utilized to measure sitosterol levels of normocholesterolemic and hypercholesterolemic children. Subsequently, an epidemiologically determined cutoff level of sitosterol was calculated and applied to estimate the prevalence of children with increased sitosterol and identify potential sitosterolemia patients. Massively parallel sequencing was used to confirm the diagnosis in suspected patients. Results Samples from 109 normocholesterolemic and 220 hypercholesterolemic were tested for phytosterols. Sitosterol and campesterol levels were significantly increased in hypercholesterolemic children (mean 22.0±45.9 μmol/L for sitosterol and 26.0±32.8 μmol/L for campesterol) compared to normocholesterolemic children (mean 12.1±4.9 μmol/L for sistosterol and 14.8±6.7 μmol/L for campesterol). Via application of a cutoff of 35.9 μmol/L, the prevalence rates for increased and overtly increased sitosterol in hypercholesterolemic children were 6.4% and 1.4% respectively. Furthermore, 3 suspected sitosterolemia patients were identified, with 2 patients receiving molecular confirmation for sitosterolemia diagnosis. Conclusions Our findings reaffirm that the prevalence of sitosterolemia is probably much higher than previously reported, which also indicates the significant risk of misdiagnosis of sitosterolemia with familial hypercholesterolemia. Special lipid testing including sitosterol, especially in children with uncontrolled hypercholesterolemia, is recommended in children in order to identify potential sitosterolemia patients that would otherwise be neglected.
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Affiliation(s)
- Joon Hee Lee
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Da Young Song
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea
| | - Sun-Hee Jun
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Sang Hoon Song
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea
| | - Choong Ho Shin
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | | | - Kyunghoon Lee
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
- * E-mail: (KL); (JS)
| | - Junghan Song
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
- * E-mail: (KL); (JS)
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14
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Abstract
PURPOSE OF REVIEW Familial hypercholesterolemia has long been considered a monogenic disorder. However, recent advances in genetic analyses have revealed various forms of this disorder, including polygenic and oligogenic familial hypercholesterolemia. We review the current understanding of the genetic background of this disease. RECENT FINDINGS Mutations in multiple alleles responsible for low-density lipoprotein regulation could contribute to the development of familial hypercholesterolemia, especially among patients with mutation-negative familial hypercholesterolemia. In oligogenic familial hypercholesterolemia, multiple rare genetic variations contributed to more severe familial hypercholesterolemia. SUMMARY Familial hypercholesterolemia is a relatively common 'genetic' disorder associated with an extremely high risk of developing coronary artery disease. In addition to monogenic familial hypercholesterolemia, different types of familial hypercholesterolemia, including polygenic and oligogenic familial hypercholesterolemia, exist and have varying degrees of severity. Clinical and genetic assessments for familial hypercholesterolemia and clinical risk stratifications should be performed for accurate diagnosis, as should cascade screening and risk stratification for the offspring of affected patients.
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Affiliation(s)
- Hayato Tada
- Department of Cardiovascular and Internal Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
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15
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Sharma A, Rather GA, Misra P, Dhar MK, Lattoo SK. Jasmonate responsive transcription factor WsMYC2 regulates the biosynthesis of triterpenoid withanolides and phytosterol via key pathway genes in Withania somnifera (L.) Dunal. Plant Mol Biol 2019; 100:543-560. [PMID: 31090025 DOI: 10.1007/s11103-019-00880-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
Functional characterization of WsMYC2 via artificial microRNA mediated silencing and transient over-expression displayed significant regulatory role vis-à-vis withanolides and stigmasterol biosyntheses in Withania somnifera. Further, metabolic intensification corroborated well with higher expression levels of putative pathway genes. Additionally, copious expression of WsMYC2 in response to exogenous elicitors resulted in enhanced withanolides production. Withania somnifera, a high value multipurpose medicinal plant, is a rich reservoir of structurally diverse and biologically active triterpenoids known as withanolides. W. somnifera has been extensively pursued vis-à-vis pharmacological and chemical studies. Nonetheless, there exists fragmentary knowledge regarding the metabolic pathway and the regulatory aspects of withanolides biosynthesis. Against this backdrop, a jasmonate-responsive MYC2 transcription factor was identified and functionally characterized from W. somnifera. In planta transient over-expression of WsMYC2 showed significant enhancement of mRNA transcript levels which corroborated well with the enhanced content of withanolides and stigmasterol. Further, a comparative analysis of expression levels of some of the genes of triterpenoid pathway viz. WsCAS, WsCYP85A, WsCYP90B and WsCYP710A in corroboration with the over-expression and silencing of WsMYC2 suggested its positive influence on their regulation. These corroboratory approaches suggest that WsMYC2 has cascading effect on over-expression of multiple pathway genes leading to the increased triterpenoid biosynthesis in infiltered plants. Further, the functional validation of WsMYC2 was carried out by artificial micro-RNA mediated silencing. It resulted in significant reduction of withanolides and stigmasterol levels, indicative of crucial role of WsMYC2 in the regulation of their biosyntheses. Taken together, these non-complementary approaches provided unambiguous understanding of the regulatory role of WsMYC2 in context to withanolides and stigmasterol biosyntheses. Furthermore, the upstream promoter of WsMYC2 presented several cis-regulatory elements primarily related to phytohormone responsiveness. WsMYC2 displayed inducible nature in response to MeJA. It had substantial influence on the higher expression of WsMYC2 which was in consonance with enhanced accumulation of withanolides.
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Affiliation(s)
- Arti Sharma
- Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India
| | - Gulzar A Rather
- Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India
| | - Prashant Misra
- Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India
| | - Manoj K Dhar
- School of Biotechnology, Department of Life Sciences, University of Jammu, Jammu Tawi, 180006, India.
| | - Surrinder K Lattoo
- Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.
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16
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Abstract
RATIONALE Sitosterolemia is a rare autosomal recessive disorder of dyslipidemia due to mutations of genes ABCG5 and ABCG8, leading to highly elevated plasma levels of plant sterols and expanded body pools of cholesterol. PATIENT CONCERNS We present a 9-year-old and a 7-year-old Chinese boy with hypercholesterolemia and xanthomas of sitosterolemia due to ABCG5 gene mutations. We also make a literature review of another 30 sitosterolemic children cases that have been reported with virulence ABCG5 gene mutations. DIAGNOSIS We took peripheral blood samples from 2 patients and their parents to conduct genetic analysis by next-generation sequencing (NGS) technologies. INTERVENTIONS The 2 patients received dietary modifications without pharmaceuticals treatment. OUTCOMES A c.1166G>A (Arg389His) homozygosis mutation in exon 9 was observed in case 1, whereas a c.751C>T (Gln251*) homozygosis mutation in exon 6 was found in case 2. Literature review found another 30 pediatric cases with sitosterolemia due to ABCG5 gene mutation. The lipid profile was normalized and xanthomas got smaller with combined therapy of a combined low-cholesterol and low-phytosterols diet. LESSONS These suggested that in patients (especially Asian patients) with multiple xanthomas, severe hypercholesterolemia, or elevated low-density lipoprotein-cholesterol, sitosterolemia should be considered in the differential diagnosis. Early diagnosis is important, and restriction of both cholesterol and phytosterols diet should suggested for these patients.
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Affiliation(s)
- Dan Huang
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine
| | - Qiong Zhou
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine
- Department of Pediatrics, Hangzhou Children's Hospital, Hangzhou, China
| | - Yun-Qi Chao
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine
| | - Chao-Chun Zou
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine
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17
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Nahirñak V, Rivarola M, Almasia NI, Barrios Barón MP, Hopp HE, Vile D, Paniego N, Vazquez Rovere C. Snakin-1 affects reactive oxygen species and ascorbic acid levels and hormone balance in potato. PLoS One 2019; 14:e0214165. [PMID: 30909287 PMCID: PMC6433472 DOI: 10.1371/journal.pone.0214165] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/08/2019] [Indexed: 12/19/2022] Open
Abstract
Snakin-1 is a member of the Solanum tuberosum Snakin/GASA family. We previously demonstrated that Snakin-1 is involved in plant defense to pathogens as well as in plant growth and development, but its mechanism of action has not been completely elucidated yet. Here, we showed that leaves of Snakin-1 silenced potato transgenic plants exhibited increased levels of reactive oxygen species and significantly reduced content of ascorbic acid. Furthermore, Snakin-1 silencing enhanced salicylic acid content in accordance with an increased expression of SA-inducible PRs genes. Interestingly, gibberellic acid levels were also enhanced and transcriptome analysis revealed that a large number of genes related to sterol biosynthesis were downregulated in these silenced lines. Moreover, we demonstrated that Snakin-1 directly interacts with StDIM/DWF1, an enzyme involved in plant sterols biosynthesis. Additionally, the analysis of the expression pattern of PStSN1::GUS in potato showed that Snakin-1 is present mainly in young tissues associated with active growth and cell division zones. Our comprehensive analysis of Snakin-1 silenced lines demonstrated for the first time in potato that Snakin-1 plays a role in redox balance and participates in a complex crosstalk among different hormones.
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Affiliation(s)
- Vanesa Nahirñak
- Instituto de Biotecnología, CICVyA, CNIA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires, Argentina
| | - Máximo Rivarola
- Instituto de Biotecnología, CICVyA, CNIA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Natalia Inés Almasia
- Instituto de Biotecnología, CICVyA, CNIA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires, Argentina
| | | | - Horacio Esteban Hopp
- Instituto de Biotecnología, CICVyA, CNIA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires, Argentina
| | - Denis Vile
- LEPSE, Univ Montpellier, INRA, SupAgro, Montpellier, France
| | - Norma Paniego
- Instituto de Biotecnología, CICVyA, CNIA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Cecilia Vazquez Rovere
- Instituto de Biotecnología, CICVyA, CNIA, Instituto Nacional de Tecnología Agropecuaria (INTA), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- INTA LABINTEX Agropolis International, Montpellier, France
- * E-mail:
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18
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Tada H, Nohara A, Inazu A, Sakuma N, Mabuchi H, Kawashiri MA. Sitosterolemia, Hypercholesterolemia, and Coronary Artery Disease. J Atheroscler Thromb 2018; 25:783-789. [PMID: 30033951 PMCID: PMC6143779 DOI: 10.5551/jat.rv17024] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 05/24/2018] [Indexed: 12/31/2022] Open
Abstract
Sitosterolemia is a rare inherited disease characterized by increased levels of plant sterols, such as sitosterol. The cause of this disease is ATP-binding cassette (ABC) subfamily G member 5 or member 8 (ABCG5 or ABCG8, respectively) gene mutations. Recent advances in genetics have revealed that the prevalence of subjects with deleterious mutations in ABCG5 and/or ABCG8 genes could be more than 1 in ~200,000 individuals among the general population. Furthermore, accumulated evidence, including infantile cases exhibiting progression/regression of systemic xanthomas associated with LDL cholesterol levels, have shown that the elevation of LDL cholesterol seems to be the major cause of development of atherosclerosis and not the elevation of sitosterol. Regarding therapies, LDL apheresis, as well as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, could be useful for sitosterolemia, in addition to ezetimibe and/or colestimide. In this study, we provide the current understanding and future perspectives of sitosterolemia, which is currently considered an extremely rare disorder but is expected to be much more prevalent in clinical settings.
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Affiliation(s)
- Hayato Tada
- Department of Cardiovascular and Internal Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Atsushi Nohara
- Department of Cardiovascular and Internal Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Akihiro Inazu
- Department of Laboratory Science, Molecular Biochemistry and Molecular Biology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Nagahiko Sakuma
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroshi Mabuchi
- Department of Cardiovascular and Internal Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Masa-aki Kawashiri
- Department of Cardiovascular and Internal Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
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Bastida JM, Benito R, Janusz K, Díez-Campelo M, Hernández-Sánchez JM, Marcellini S, Girós M, Rivera J, Lozano ML, Hortal A, Hernández-Rivas JM, González-Porras JR. Two novel variants of the ABCG5 gene cause xanthelasmas and macrothrombocytopenia: a brief review of hematologic abnormalities of sitosterolemia. J Thromb Haemost 2017; 15:1859-1866. [PMID: 28696550 DOI: 10.1111/jth.13777] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Indexed: 12/24/2022]
Abstract
Essentials Diagnosis of sitosterolemia, a rare recessive or syndromic disorder, is usually delayed. Peripheral blood smear is extremely useful for establishing the suspicion of sitosterolemia. High-throughput sequencing technology enables the molecular diagnosis of inherited thrombocytopenias. Accurate characterization of sitosterolemia helps us determine appropriate management. SUMMARY Background Sitosterolemia (STSL) is a recessive inherited disorder caused by pathogenic variants in the ABCG5 and ABCG8 genes. Increased levels of plasma plant sterols (PSs) usually result in xanthomas and premature coronary atherosclerosis, although hematologic abnormalities may occasionally be present. This clinical picture is unfamiliar to many physicians, and patients may be at high risk of misdiagnosis. Objectives To report two novel ABCG5 variants causing STSL in a Spanish patient, and review the clinical and mutational landscape of STSL. Patient/Methods A 46-year-old female was referred to us with lifelong macrothrombocytopenia. She showed familial hypercholesterolemia-related xanthomas. Molecular analysis was performed with high-throughput sequencing. Plasma PS levels were evaluated with gas-liquid chromatography. The STSL landscape was reviewed with respect to specific online databases and all reports published since 1974. Results A blood smear revealed giant platelets and stomatocytes. Novel compound heterozygous variants were detected in exons 7 (c.914C>G) and 13 (c.1890delT) of ABCG5. The patient showed an increased plasma level of sitosterol. These findings support the diagnosis of STSL. In our review, we identified only 25 unrelated STLS patients who presented with hematologic abnormalities including macrothrombocytopenia. It remains unknown why only some patients develop hematologic abnormalities. Conclusions This is the first Spanish STSL patient to be reported and molecularly characterized. The early diagnosis of STLS is strongly supported by the presence of stomatocytes in blood smears. The definitive diagnosis of STSL by measurement of serum PS levels and molecular analyses prompted the use of ezetimibe therapy.
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Affiliation(s)
- J M Bastida
- Department of Hematology, Hospital Universitario de Salamanca-IBSAL-USAL, Salamanca, Spain
| | - R Benito
- IBSAL, IBMCC, CIC, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - K Janusz
- IBSAL, IBMCC, CIC, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - M Díez-Campelo
- Department of Hematology, Hospital Universitario de Salamanca-IBSAL-USAL, Salamanca, Spain
| | | | - S Marcellini
- Department of Hematology, Hospital General de Segovia, Segovia, Spain
| | - M Girós
- Secció d'Errors Congènits del Metabolisme-IBC, Servei de Bioquímica i Genètica Molecular Hospital Clínic Barcelona, IDIBAPS, CIBERER, Barcelona, Spain
| | - J Rivera
- Department of Hematology and Oncology, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, CB15/00055-CIBERER, Murcia, Spain
| | - M L Lozano
- Department of Hematology and Oncology, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, CB15/00055-CIBERER, Murcia, Spain
| | - A Hortal
- Department of Pediatrics, Hospital Universitario de Salamanca-IBSAL-USAL, Salamanca, Spain
| | - J M Hernández-Rivas
- Department of Hematology, Hospital Universitario de Salamanca-IBSAL-USAL, Salamanca, Spain
- IBSAL, IBMCC, CIC, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - J R González-Porras
- Department of Hematology, Hospital Universitario de Salamanca-IBSAL-USAL, Salamanca, Spain
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Abstract
The importance of the pathogenic mycobacteria has mainly focused the omic analyses on different aspects of their clinical significance. In contrast, those industrially relevant mycobacteria have received less attention, even though the steroids market sales in 2011, in example, were estimated in $8 billion.The extra-cellular proteome, due to its relevance in the sterols processing and uptake; as well as the intra-cellular proteome, because of its role in steroids bioconversion, are the core of the present chapter. As a proof of concept, the obtaining methods for both sub-proteomes of Mycobacterium neoaurum NRRL B-3805, a relevant industrial strain involved in steroids production, have been developed. Thus, procedures and relevant key points of these proteomes analyses are fully described.
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Affiliation(s)
- Carlos Barreiro
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Avda. Real 1, 24006, León, Spain.
- Área de Microbiología, Departamento de Biología Molecular, Campus de Ponferrada, Universidad de León, Avda. Astorga, s/n, 24400, Ponferrada, Spain.
| | - Alejandro Morales
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Avda. Real 1, 24006, León, Spain
| | - Inés Vázquez-Iglesias
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Avda. Real 1, 24006, León, Spain
| | - Alberto Sola-Landa
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Avda. Real 1, 24006, León, Spain
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Abstract
A young girl, age 8.5 years, presented with profound hypercholesterolemia and early xanthomatosis, suggesting homozygous familial (or type II) hypercholesterolemia. The patient's low density lipoprotein (LDL) receptor function and parental lipoprotein profiles were determined to be normal, prompting revision of the initial diagnosis to pseudohomozygous familial hypercholesterolemia. When she subsequently presented with giant platelets, the case was presented to colleagues on an electronic mailing list. It was recommended that plasma and sterol analysis be performed, which led to a diagnosis of sitosterolemia. The presentation of profound hypercholesterolomia in childhood that ultimately is not attributed as due to homozygous or compound heterozygous defects in the LDL receptor gene has been termed pseudohomozygous familial (or type II) hypercholesterolemia (PHT2HC). Patients diagnosed with PHT2HC subsequently confirmed to have sitosterolemia have been previously reported only rarely. The challenge of achieving accurate specific diagnosis and appropriate workup for these conditions in children is discussed in the context of this rare case and review of the historical literature concerning these conditions.
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Affiliation(s)
- Christian Renner
- Kinder und Jugendart Praxis, Pfleggasse 31, D-94469 Deggendorf, Germany
| | - William E Connor
- Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA
| | - Robert D Steiner
- Department of Pediatrics and Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA Marshfield Clinic Research Foundation, Marshfield, USA
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Abstract
Phytosterolemia (sitosterolemia) is a rare autosomal recessive sterol storage disease caused by mutations in either of the adenosine triphosphate (ATP) binding cassette transporter genes; (ABC) G5 or ABCG8, leading to impaired elimination of plant sterols and stanols, with their increased accumulation in the blood and tissues. Thus the disease is characterized by substantially elevated serum plant sterols and stanols, with moderate to high plasma cholesterol levels, and increased risk of premature atherosclerosis. Hematologic abnormalities including macrothrombocytopenia, stomatocytosis and hemolysis are frequently observed in sitosterolemia patients. Currently, ezetimibe, a sterol absorption inhibitor, is used as the routine treatment for sitosterolemia, with reported improvement in plant sterol levels and hemolytic parameters. This review summarizes the research related to the health impact of plant sterols and stanols on sitosterolemia.
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Affiliation(s)
- Bridget O. Ajagbe
- University of Manitoba, Department of Human Nutritional Sciences, Winnipeg, MB, Canada, R3T 2N2, and University of Manitoba, Richardson Centre for Functional Foods and Nutraceuticals, Winnipeg, MB, Canada, R3T 6C5
| | - Rgia A. Othman
- University of Manitoba, Department of Human Nutritional Sciences, Winnipeg, MB, Canada, R3T 2N2, and University of Manitoba, Richardson Centre for Functional Foods and Nutraceuticals, Winnipeg, MB, Canada, R3T 6C5
| | - Semone B. Myrie
- University of Manitoba, Department of Human Nutritional Sciences, Winnipeg, MB, Canada, R3T 2N2, and University of Manitoba, Richardson Centre for Functional Foods and Nutraceuticals, Winnipeg, MB, Canada, R3T 6C5
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Wang X, Chen D, Wang Y, Xie J. De novo transcriptome assembly and the putative biosynthetic pathway of steroidal sapogenins of Dioscorea composita. PLoS One 2015; 10:e0124560. [PMID: 25860891 PMCID: PMC4393236 DOI: 10.1371/journal.pone.0124560] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 03/16/2015] [Indexed: 11/19/2022] Open
Abstract
The plant Dioscorea composita has important applications in the medical and energy industries, and can be used for the extraction of steroidal sapogenins (important raw materials for the synthesis of steroidal drugs) and bioethanol production. However, little is known at the genetic level about how sapogenins are biosynthesized in this plant. Using Illumina deep sequencing, 62,341 unigenes were obtained by assembling its transcriptome, and 27,720 unigenes were annotated. Of these, 8,022 unigenes were mapped to 243 specific pathways, and 531 unigenes were identified to be involved in 24 secondary metabolic pathways. 35 enzymes, which were encoded by 79 unigenes, were related to the biosynthesis of steroidal sapogenins in this transcriptome database, covering almost all the nodes in the steroidal pathway. The results of real-time PCR experiments on ten related transcripts (HMGR, MK, SQLE, FPPS, DXS, CAS, HMED, CYP51, DHCR7, and DHCR24) indicated that sapogenins were mainly biosynthesized by the mevalonate pathway. The expression of these ten transcripts in the tuber and leaves was found to be much higher than in the stem. Also, expression in the shoots was low. The nucleotide and protein sequences and conserved domains of four related genes (HMGR, CAS, SQS, and SMT1) were highly conserved between D. composita and D. zingiberensis; but expression of these four genes is greater in D. composita. However, there is no expression of these key enzymes in potato and no steroidal sapogenins are synthesized.
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Affiliation(s)
- Xia Wang
- Institute of New Energy and New Materials, South China Agriculture University, Guangzhou, 510642, P. R. China
- Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, Guangzhou, 510642, P. R. China
- Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, P. R. China, Guangzhou, 510642, P. R. China
| | - Dijia Chen
- Institute of New Energy and New Materials, South China Agriculture University, Guangzhou, 510642, P. R. China
- Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, Guangzhou, 510642, P. R. China
- Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, P. R. China, Guangzhou, 510642, P. R. China
| | - Yuqi Wang
- Institute of New Energy and New Materials, South China Agriculture University, Guangzhou, 510642, P. R. China
- Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, Guangzhou, 510642, P. R. China
- Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, P. R. China, Guangzhou, 510642, P. R. China
| | - Jun Xie
- Institute of New Energy and New Materials, South China Agriculture University, Guangzhou, 510642, P. R. China
- Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, Guangzhou, 510642, P. R. China
- Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, P. R. China, Guangzhou, 510642, P. R. China
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Abstract
PURPOSE OF REVIEW To provide an update on recent advances made in our mechanistic and pathophysiological understanding of the rare human disease Sitosterolemia, the role of ABCG5/ABCG8 in sterol trafficking and how newer data implicate a more wider role in the body. RECENT FINDINGS Sitosterolemia is caused by a genetic defect of sterolins (ABCG5/ABCG8) mapped to the STSL locus. Polymorphic variations in STSL have been linked to lipid levels and gallstone disease in whites. Newer studies now link this locus to a more diverse ethnic group for gallstone disease, susceptibility to biliary cancer, and show variants that alter sterolin function. Intriguingly, carriers of a mutant allele seem to show protection against carotid wall disease. Although the 'promoter' region of the STSL is minimal, regulatory regions responsive to liver X receptor have remained elusive, but no longer; two intronic regions in ABCG8 have now been identified. Xenosterol accumulation leads to loss of abdominal fat, infertility, and premature death. Xenosterol accumulation in mouse platelet membranes leads to platelet hyperactivation, increased microparticle formation, and reduced αIIbβ3 surface expression. In humans, phytosterols may promote liver injury in parenteral nutrition-associated liver disease. SUMMARY Progress in understanding sterolin function is beginning to show that xenosterols can be toxic and are involved on pathogenesis, and the role of ABCG5/ABCG8 may extend into other metabolic processes by altering intracellular sterol metabolism.
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Affiliation(s)
- Shailendra B Patel
- aClement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, USA bDivision of Endocrinology, Metabolism and Clinical Nutrition, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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25
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Park JH, Chung IH, Kim DH, Choi MH, Garg A, Yoo EG. Sitosterolemia presenting with severe hypercholesterolemia and intertriginous xanthomas in a breastfed infant: case report and brief review. J Clin Endocrinol Metab 2014; 99:1512-8. [PMID: 24423340 DOI: 10.1210/jc.2013-3274] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CONTEXT Sitosterolemia is an autosomal recessive disorder characterized by increased intestinal absorption of plant sterols. It is caused by mutations in genes encoding ATP-binding cassette, subfamily G5 (ABCG5) or G8 (ABCG8), and clinical features include elevated plant sterol levels, xanthomas, and accelerated atherosclerosis. Although it was originally reported in patients with normolipemic xanthomas, patients with sitosterolemia also hyperabsorb cholesterol, and serum cholesterol levels tend to be elevated. OBJECTIVE We report an infant with sitosterolemia who presented with severe hypercholesterolemia and intertriginous xanthomas. CASE REPORT A 15-month-old Korean girl presented with yellow dermal plaques over flexural areas including the wrist, neck, and gluteal folds, which were consistent with intertriginous xanthomas. The lesions were first noticed at 3 months of age when she was being exclusively breastfed. Her total cholesterol and low-density lipoprotein-cholesterol levels were 675 and 540 mg/dL, respectively. A low-fat/low-cholesterol diet and cholestyramine therapy were introduced. Unexpectedly, her serum cholesterol level decreased dramatically and normalized in 2 months. Cholestyramine was tapered off. The xanthomas also regressed and disappeared by 3 years of age. Gas chromatography-mass spectrometric analysis was performed with serum drawn at 3 years of age when her low-density lipoprotein-cholesterol was 118 mg/dL, which revealed striking elevation of her sitosterol level at 19.36 mg/dL. Direct sequencing for ABCG5 revealed compound heterozygous null mutations c.904+1G>A (p.Met302Asnfs*82) and c.1336C>T(p.Arg446*). CONCLUSIONS Our case suggests that sitosterolemia can present with severe hypercholesterolemia and intertriginous xanthomas. Sitosterolemia should be suspected when a patient with hypercholesterolemia shows unexpectedly good response to dietary modification or bile acid sequestrant therapy.
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Affiliation(s)
- Joong Heum Park
- Departments of Pediatrics (J.H.P., I.H.C., E.-G.Y.) and Dermatology (D.H.K.), CHA University, Sungnam 463-712, Korea; Future Convergence Research Division (M.H.C.), Korea Institute of Science and Technology, Seoul 136-791, Korea; and Division of Nutrition and Metabolic Diseases (A.G.), Department of Internal Medicine, Center for Human Nutrition, UT Southwestern Medical Center, Dallas, Texas 75390
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26
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Nguyen HTM, Neelakadan AK, Quach TN, Valliyodan B, Kumar R, Zhang Z, Nguyen HT. Molecular characterization of Glycine max squalene synthase genes in seed phytosterol biosynthesis. Plant Physiol Biochem 2013; 73:23-32. [PMID: 24036394 DOI: 10.1016/j.plaphy.2013.07.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 07/29/2013] [Indexed: 05/21/2023]
Abstract
The reaction catalyzed by squalene synthase (EC.2.5.1.21) that converts two molecules of farnesyl pyrophosphate to squalene represents a crucial branch point of the isoprenoid pathway in diverting carbon flux towards the biosynthesis of sterols. In the present study two soybean squalene synthase genes, GmSQS1 and GmSQS2, were identified in the soybean genome and functionally characterized for their roles in sterol biosynthesis. Both genes encode a deduced protein of 413 amino acids. Complementation assays showed that the two genes were able to convert yeast sterol auxotrophy erg9 mutant to sterol prototrophy. Expression of GmSQS1 and GmSQS2 was ubiquitous in roots, stem, leaves, flower and young seeds of soybean, however GmSQS1 transcript was preferential in roots while GmSQS2 transcript was more in leaves. Their expression was lower in response to dehydration treatments suggesting they might be negative regulators of water stress adaptation. Transgenic Arabidopsis plants overexpressing GmSQS1 driven by either constitutive or seed-specific promoters showed increases in the major end product sterols: campesterol, sitosterol and stigmasterol, which resulted in up to 50% increase in total sterol content in the seeds. The increase in the end product sterols by GmSQS1 overexpression was at the level achievable by previously reported overexpression of individual or combination of other key enzymes in the sterol pathway. Together the data demonstrate that soybean SQS genes play an important role in diverting carbon flux to the biosynthesis of the end product sterols in the seeds.
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Affiliation(s)
- Hanh T M Nguyen
- Division of Plant Sciences and National Center for Soybean Biotechnology, University of Missouri, Columbia, MO 65211, USA
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27
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Behnke K, Ghirardo A, Janz D, Kanawati B, Esperschütz J, Zimmer I, Schmitt-Kopplin P, Niinemets Ü, Polle A, Schnitzler JP, Rosenkranz M. Isoprene function in two contrasting poplars under salt and sunflecks. Tree Physiol 2013; 33:562-578. [PMID: 23532135 DOI: 10.1093/treephys/tpt018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In the present study, biogenic volatile organic compound (BVOC) emissions and photosynthetic gas exchange of salt-sensitive (Populus x canescens (Aiton) Sm.) and salt-tolerant (Populus euphratica Oliv.) isoprene-emitting and non-isoprene-emitting poplars were examined under controlled high-salinity and high-temperature and -light episode ('sunfleck') treatments. Combined treatment with salt and sunflecks led to an increased isoprene emission capacity in both poplar species, although the photosynthetic performance of P. × canescens was reduced. Indeed, different allocations of isoprene precursors between the cytosol and the chloroplast in the two species were uncovered by means of (13)CO2 labeling. Populus × canescens leaves, moreover, increased their use of 'alternative' carbon (C) sources in comparison with recently fixed C for isoprene biosynthesis under salinity. Our studies show, however, that isoprene itself does not have a function in poplar survival under salt stress: the non-isoprene-emitting leaves showed only a slightly decreased photosynthetic performance compared with wild type under salt treatment. Lipid composition analysis revealed differences in the double bond index between the isoprene-emitting and non-isoprene-emitting poplars. Four clear metabolomics patterns were recognized, reflecting systemic changes in flavonoids, sterols and C fixation metabolites due to the lack/presence of isoprene and the absence/presence of salt stress. The studies were complemented by long-term temperature stress experiments, which revealed the thermotolerance role of isoprene as the non-isoprene-emitting leaves collapsed under high temperature, releasing a burst of BVOCs. Engineered plants with a low isoprene emission potential might therefore not be capable of resisting high-temperature episodes.
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Affiliation(s)
- K Behnke
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
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Wang G, Cao L, Wang Z, Jiang M, Sun X, Bai X, Ruan C. Macrothrombocytopenia/Stomatocytosis Specially Associated With Phytosterolemia. Clin Appl Thromb Hemost 2012; 18:582-7. [PMID: 22297561 DOI: 10.1177/1076029611435090] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Phytosterolemia is a rare autosomal recessive disease of plant sterol metabolism, the pathophysiological features of which are high plasma levels of plant sterols and xanthomatosis caused by mutations of ABCG5 and ABCG8 genes, and the combination of hemolysis and macrothrombocytopenia is an unusual clinical manifestation. All the patients of the 3 unrelated phytosterolemia first presented with prominent macrothrombocytopenia and stomatocytosis. They were either homozygous or compound heterozygous for ABCG5/ ABCG8 gene mutations and had significantly elevated serum plant sterols levels quantified using high-performance liquid chromatography. The in vitro study demonstrated that sitosterol can cause changes in shape and osmotic fragility of red blood cells. These findings suggest that macrothrombocytopenia and stomatocytosis could be initial and main features in some patients with phytosterolemia and that serum phytosterols and relevant genes should be analyzed in patients whose macrothrombocytopenia and/or stomatocytosis are unexplained, especially whose parents are of consanguineous marriage.
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Affiliation(s)
- Gaifeng Wang
- Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
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29
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Itkin M, Rogachev I, Alkan N, Rosenberg T, Malitsky S, Masini L, Meir S, Iijima Y, Aoki K, de Vos R, Prusky D, Burdman S, Beekwilder J, Aharoni A. GLYCOALKALOID METABOLISM1 is required for steroidal alkaloid glycosylation and prevention of phytotoxicity in tomato. Plant Cell 2011; 23:4507-25. [PMID: 22180624 PMCID: PMC3269880 DOI: 10.1105/tpc.111.088732] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 11/06/2011] [Accepted: 11/29/2011] [Indexed: 05/18/2023]
Abstract
Steroidal alkaloids (SAs) are triterpene-derived specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. Their biosynthesis involves the action of glycosyltransferases to form steroidal glycoalkaloids (SGAs). To elucidate the metabolism of SGAs in the Solanaceae family, we examined the tomato (Solanum lycopersicum) GLYCOALKALOID METABOLISM1 (GAME1) gene. Our findings imply that GAME1 is a galactosyltransferase, largely performing glycosylation of the aglycone tomatidine, resulting in SGA production in green tissues. Downregulation of GAME1 resulted in an almost 50% reduction in α-tomatine levels (the major SGA in tomato) and a large increase in its precursors (i.e., tomatidenol and tomatidine). Surprisingly, GAME1-silenced plants displayed growth retardation and severe morphological phenotypes that we suggest occur as a result of altered membrane sterol levels caused by the accumulation of the aglycone tomatidine. Together, these findings highlight the role of GAME1 in the glycosylation of SAs and in reducing the toxicity of SA metabolites to the plant cell.
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Affiliation(s)
- Maxim Itkin
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ilana Rogachev
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Noam Alkan
- Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Tally Rosenberg
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Sergey Malitsky
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Laura Masini
- Plant Research International, Wageningen 6700 AA, The Netherlands
| | - Sagit Meir
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yoko Iijima
- Kazusa DNA Research Institute, Kisarazu 292-0818, Japan
| | - Koh Aoki
- Kazusa DNA Research Institute, Kisarazu 292-0818, Japan
| | - Ric de Vos
- Plant Research International, Wageningen 6700 AA, The Netherlands
| | - Dov Prusky
- Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Saul Burdman
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Jules Beekwilder
- Plant Research International, Wageningen 6700 AA, The Netherlands
| | - Asaph Aharoni
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
- Address correspondence to
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30
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Mazorra LM, Holton N, Bishop GJ, Núñez M. Heat shock response in tomato brassinosteroid mutants indicates that thermotolerance is independent of brassinosteroid homeostasis. Plant Physiol Biochem 2011; 49:1420-8. [PMID: 22078379 DOI: 10.1016/j.plaphy.2011.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 09/09/2011] [Indexed: 05/11/2023]
Abstract
Brassinosteroids (BRs) are plant steroid hormones and, when applied exogenously, they induce physiological responses, including tolerance to heat shock (HS). How endogenous BR content and altered perception of BRs influence thermal tolerance is poorly understood. BR-induced thermotolerance in tomato seedlings with altered BR homeostasis was examined by assessing the survival, ion leakage and lipid peroxidation of seedlings from a BR-deficient mutant (extreme dwarf d(x)), a partially BR-insensitive mutant curl3(-abs) allele (curl3 altered brassinolide sensitivity) and a line overexpressing the Dwarf, BR-biosynthesis gene (35SD). We confirmed that treatment with 1 μM of epi-brassinolide (EBL) induces thermotolerance of wild type seedlings following a HS regime at 45 °C. The curl3(-abs) seedlings had the highest basal tolerance to heat, whereas the EBL-induced thermal tolerance of d(x) seedlings was greatest and responded to lower EBL concentrations. The d(x) and 35SD seedlings had similar thermal tolerance; however, they showed increased signs of oxidative stress. EBL reduced the induction of lipid peroxidation of seedlings after recovery from heat. Highest oxidative stress and peroxidase (POX) activity (EC 1.11.1.7) was in BR-deficient d(x) mutant seedlings. EBL was able of inducing POX activity but not other antioxidant enzymes; however, effects of HS on POX activity of seedlings were absent or less marked. Taking together, results indicate that thermal tolerance is independent of endogenous BR content, but HS-mediated oxidative stress depends on BR levels.
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Affiliation(s)
- Luis Miguel Mazorra
- National Institute of Agricultural Sciences, CP No.1, San José de las Lajas, Havana, Cuba.
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31
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Itkin M, Rogachev I, Alkan N, Rosenberg T, Malitsky S, Masini L, Meir S, Iijima Y, Aoki K, de Vos R, Prusky D, Burdman S, Beekwilder J, Aharoni A. GLYCOALKALOID METABOLISM1 is required for steroidal alkaloid glycosylation and prevention of phytotoxicity in tomato. Plant Cell 2011. [PMID: 22180624 DOI: 10.1105/tpc.111.08873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Steroidal alkaloids (SAs) are triterpene-derived specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. Their biosynthesis involves the action of glycosyltransferases to form steroidal glycoalkaloids (SGAs). To elucidate the metabolism of SGAs in the Solanaceae family, we examined the tomato (Solanum lycopersicum) GLYCOALKALOID METABOLISM1 (GAME1) gene. Our findings imply that GAME1 is a galactosyltransferase, largely performing glycosylation of the aglycone tomatidine, resulting in SGA production in green tissues. Downregulation of GAME1 resulted in an almost 50% reduction in α-tomatine levels (the major SGA in tomato) and a large increase in its precursors (i.e., tomatidenol and tomatidine). Surprisingly, GAME1-silenced plants displayed growth retardation and severe morphological phenotypes that we suggest occur as a result of altered membrane sterol levels caused by the accumulation of the aglycone tomatidine. Together, these findings highlight the role of GAME1 in the glycosylation of SAs and in reducing the toxicity of SA metabolites to the plant cell.
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Affiliation(s)
- Maxim Itkin
- Department of Plant Sciences, Weizman Institute of Science, Rehovot, Israel
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Wang GF, Wang ZY, Cao LJ, Jiang MH, Sun XH, Bai X, Ruan CG. [Clinical and gene study of three pedigrees of phytosterolemia associated with macrothrombocytopenia and hemolysis]. Zhonghua Xue Ye Xue Za Zhi 2011; 32:331-336. [PMID: 21729603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To study the clinical features and ABCG5/ABCG8 gene mutations of three pedigrees of phytosterolemia presented with macrothrombocytopenia and hemolysis. METHODS Erythrocyte and platelet morphology were examined under light microscope. Plasma sterol levels were measured by high pressure/performance liquid chromatography method. All of ABCG5 and ABCG8 exons and intron-exon boundaries were directly sequenced to identify mutations, the corresponding gene mutation sites of three families members and healthy individuals were detected. RESULTS All the patients presented macrothrombocytopenia, hemolysis, splenomegaly and xanthomas. The blood smears showed large platelets, some as large as erythrocytes, and abnormal erythrocyte shapes, such as stomatocytes. Plasma concentrations of phytosterols, especially sitosterol were markedly elevated (30 fold) in the affected patients. Four mutations were identified in these three pedigrees, ABCG5 C20896T (R446X) and A20883G, ABCG8 del43683-43724 and del1938C-1939G/ins1938T. The latter three were novel mutations reported for the first time. CONCLUSIONS Phytosterolemia associated with macrothrombocytopenia and hemolysis is a new subtype of this disease. Plasma phytosterols and related gene analysis should be performed when ever an unexplained macrothrombocytopenia, especially combined with haemolysis or/and stomatocytosis.
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Affiliation(s)
- Gai-feng Wang
- Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou 215006, China
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van den Kommer TN, Dik MG, Comijs HC, Lütjohann D, Lips P, Jonker C, Deeg DJH. The role of extracerebral cholesterol homeostasis and ApoE e4 in cognitive decline. Neurobiol Aging 2011; 33:622.e17-28. [PMID: 21482441 DOI: 10.1016/j.neurobiolaging.2011.02.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 02/15/2011] [Accepted: 02/24/2011] [Indexed: 01/07/2023]
Abstract
We examined the associations between extracerebral markers of cholesterol homeostasis and cognitive decline over 6 years of follow-up, and studied the modifying effect of apolipoprotein E (ApoE) e4. Data were collected in the Longitudinal Aging Study Amsterdam (n = 967, with longitudinal data on cognition, ages ≥ 65 years) and analyzed using linear mixed models. General cognition (Mini-Mental State Examination; MMSE), memory (Auditory Verbal Learning Test), and information processing speed (Coding task) were measured. The results show that ApoE e4 was a significant effect modifier. Significant associations were found only in ApoE e4 noncarriers (n = 718). We found a nonlinear negative association between the ratio of lanosterol to cholesterol (≤ 189.96 ng/mg), a marker for cholesterol synthesis, and general cognition. Lower cholesterol absorption, i.e., lower ratios of campesterol and sitosterol to cholesterol, as well as a higher rate of cholesterol synthesis relative to absorption were associated with lower information processing speed. In ApoE e4 carriers, the negative association between the ratio of campesterol to cholesterol and memory reached borderline significance. Future research should focus on the interaction between (disturbed) cholesterol homeostasis and ApoE e4 status with respect to dementia.
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Affiliation(s)
- Tessa N van den Kommer
- Longitudinal Aging Study Amsterdam and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
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