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Abo-Zaid OA, Moawed FS, Ismail ES, Farrag MA. β-sitosterol attenuates high- fat diet-induced hepatic steatosis in rats by modulating lipid metabolism, inflammation and ER stress pathway. BMC Pharmacol Toxicol 2023; 24:31. [PMID: 37173727 PMCID: PMC10182633 DOI: 10.1186/s40360-023-00671-0] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic hepatic disorder. The naturally occurring phytosterol; β-sitosterol has antiobesogenic and anti-diabetic properties. The purpose of this study was to explore the role of β-sitosterol in preventing hepatic steatosis induced by a high-fat diet (HFD) in rats. In the current study, to induce NAFLD in the female Wister rats, an HFD was administered to them for 8 weeks. The pathogenic severity of steatosis in rats receiving an HFD diet was dramatically decreased by oral administration of β-sitosterol. After administering β-sitosterol to HFD-induced steatosis for three weeks, several oxidative stress-related markers were then assessed. We showed that β-sitosterol reduced steatosis and the serum levels of triglycerides, transaminases (ALT and AST) and inflammatory markers (IL-1β and iNOS) compared to HFD-fed rats. Additionally, β-sitosterol reduced endoplasmic reticulum stress by preventing the overexpression of inositol-requiring enzyme-1 (IRE-1α), X-box binding protein 1(sXBP1) and C/EBP homologous protein (CHOP) genes which, showing a function in the homeostatic regulation of protein folding. Also, it was found that the expression of the lipogenic factors; peroxisome proliferator-activated receptor (PPAR-α), sterol regulatory element binding protein (SREBP-1c) and carnitine palmitoyltransferase-1(CPT-1), which are involved in the regulation of the fatty acid oxidation process, may be regulated by β-sitosterol. It can be concluded that β-sitosterol may prevent NAFLD by reducing oxidative stress, endoplasmic reticulum stress and inflammatory responses, which supports the possibility of using β-sitosterol as an alternative therapy for NAFLD. Together, β-sitosterol may be an option for NAFLD prevention.
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Affiliation(s)
- Omayma Ar Abo-Zaid
- Molecular Biology Department, Faculty of Vet. Med, Benha University, Banha, Egypt
| | - Fatma Sm Moawed
- Health Radiation Research, National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority, Cairo, Egypt.
| | - Effet Soliman Ismail
- Molecular Biology Department, Faculty of Vet. Med, Benha University, Banha, Egypt
| | - Mostafa A Farrag
- Radiation Biology, National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority, Cairo, Egypt
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Niu X, Han P, Liu J, Chen Z, Zhang T, Li B, Ma X, Wu Q, Ma X. Regulation of PPARγ/ CPT-1 expression ameliorates cochlear hair cell injury by regulating cellular lipid metabolism and oxidative stress. Mol Genet Genomics 2023; 298:473-483. [PMID: 36639590 DOI: 10.1007/s00438-023-01993-8] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023]
Abstract
This study aimed to investigate the protective effects of PPARγ/CPT-1 regulation on cisplatin-induced cochlear hair cell injury. The viability, apoptosis and mitochondrial membrane potential of cisplatin-induced HEI-OC1 cells were determined by CCK-8 assay, TUNEL and JC-1 staining, respectively. The oxidative stress and lipid metabolism were detected by the assay kits of MDA, ROS, SOD, CAT, TG and FFA. The transfection efficiency of overexpression (OV)-PPARG and OV-CPT1A was examined by RT-qPCR and the expressions of apoptosis- and lipid metabolism-related proteins were detected by western blot. As a result, cisplatin with varying concentrations (5, 10, 30 μM) suppressed the viability, promoted the apoptosis and hindered the mitochondrial function of HEI-OC1 cells, accompanied with up-regulated expressions of Bax and cleaved caspase-3 and down-regulated expression of Bcl-2. The oxidative stress was aggravated and lipid metabolism was inhibited by cisplatin (5, 10, 30 μM) induction, evidenced by the increased levels of MDA, ROS, TG, FFA and the decreased levels of SOD and CAT. Overexpression of PPARG or CPT1A could improve the viability, mitochondrial function, lipid metabolism and suppress the oxidative stress and apoptosis of cisplatin-induced HEI-OC1 cells. In conclusion, up-regulation of PPARG or CPT1A ameliorated cochlear hair cell injury by improving cellular lipid metabolism and inhibiting oxidative stress.
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Affiliation(s)
- Xiaorong Niu
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Peng Han
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Junsong Liu
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Zichen Chen
- Department of Otorhinolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi, China
| | - Ting Zhang
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Baiya Li
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Xiaoyan Ma
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Qun Wu
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Xudong Ma
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, #227 Yanta West Road, Xi'an, 710061, Shaanxi, China.
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3
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Zheng Y, Hu Q, Wu J. Adiponectin ameliorates placental injury in gestational diabetes mice by correcting fatty acid oxidation/peroxide imbalance-induced ferroptosis via restoration of CPT-1 activity. Endocrine 2022; 75:781-793. [PMID: 34859390 DOI: 10.1007/s12020-021-02933-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [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] [Received: 09/11/2021] [Accepted: 10/28/2021] [Indexed: 01/18/2023]
Abstract
PURPOSE In gestational diabetes (GDM), abnormalities occur not only in glucose metabolism, but also in lipid metabolism. Adiponectin (ADPN) plays an important role in the regulation of lipid metabolism. In this paper, the role and mechanism of ADPN in GDM are discussed. METHODS GDM model was formed in pregnant mice induced by high-fat diet and streptozotocin, and blood glucose level was detected after ADPN treatment. The levels of TG, TC, HDL-C, and LDL-C in blood lipid of mice were detected by biochemical apparatus. HE staining was used to detect the placenta damage in mice. The expression of oxidative stress-related indexes in placental tissues was also detected by ELISA. Placental iron deposition was detected by Prussian blue staining. Redox capacity of placental tissue was detected by ELISA. Western blot was used to detect the expression of ferroptosis-related proteins in placental tissues. The expression of ADPN in placenta and peripheral blood was detected by ELISA, and the expression of ADPNR, downstream CPT-1, and GLUT4 of placenta were detected by RT-qPCR and western blot. Subsequently, trophoblast cells were induced by palmitic acid and glucose, and the cell activity was detected by CCK-8. The results in animal experiments were verified in cell experiments by RT-qPCR, western blot, and fluorescence labeling of iron ions. Finally, ADPN and CPT-1 inhibitor PM were given to trophoblast cells to further explore the mechanism. RESULTS ADPN inhibited blood glucose and lipid levels in GDM mice. ADPN inhibited oxidation/peroxide imbalance-induced ferroptosis in placental tissues of GDM mice. ADPN inhibited the expression of CPT-1 and GLUT4 in placental tissues of GDM mice. This result was also confirmed in cell experiments, and this process may be achieved by regulating CPT-1. CONCLUSIONS ADPN ameliorated placental injury in GDM by correcting fatty acid oxidation/peroxide imbalance-induced ferroptosis via restoration of CPT-1 activity.
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Affiliation(s)
- Yifang Zheng
- Department of Obstetrics and Gynecology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, Shanxi, 030002, China
| | - Qiaosheng Hu
- Department of Nutrition, Lianshui County People's Hospital, Lianshui, Jiangsu, 223400, China
| | - Jieli Wu
- Department of Obstetrics and Gynecology, Wenzhou Central Hospital, Wenzhou, Zhejiang, 325000, China.
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Zhou Y, Liu Z, Liu Z, Zhou H, Xu X, Li Z, Chen H, Wang Y, Zhou Z, Wang M, Lai Y, Zhou L, Zhou X, Jiang H. Ventromedial Hypothalamus Activation Aggravates Hypertension Myocardial Remodeling Through the Sympathetic Nervous System. Front Cardiovasc Med 2021; 8:737135. [PMID: 34733893 PMCID: PMC8558385 DOI: 10.3389/fcvm.2021.737135] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The ventromedial hypothalamus (VMH) is an important nuclei in responding to emotional stress, and emotional stress is a risk factor for cardiovascular diseases. However, the role of the VMH in cardiovascular diseases remains unknown. This study aimed to investigate the effects and underlying mechanisms of VMH activation on hypertension related cardiac remodeling in two-kidney-one-clip (2K1C) hypertension (HTN) rats. Methods: Eighteen male Sprague-Dawley rats were injected with AAV-hSyn-hM3D(Gq) into the VMH at 0 weeks and then randomly divided into three groups: (1) sham group (sham 2K1C + saline i.p. injection); (2) HTN group (2K1C + saline i.p. injection); (3) HTN+VMH activation group (2K1C + clozapine-N-oxide i.p. injection). One week later, rats were subjected to a sham or 2K1C operation, and 2 weeks later rats were injected with clozapine-N-oxide or saline for 2 weeks. Results: In the HTN+VMH activation group, FosB expression was significantly increased in VMH sections compared with those of the other two groups. Compared to the HTN group, the HTN+VMH activation group showed significant: (1) increases in systolic blood pressure (SBP); (2) exacerbation of cardiac remodeling; and (3) increases in serum norepinephrine levels and sympathetic indices of heart rate variability. Additionally, myocardial RNA-sequencing analysis showed that VMH activation might regulate the HIF-1 and PPAR signal pathway and fatty acid metabolism. qPCR results confirmed that the relative mRNA expression of HIF-1α was increased and the PPARα and CPT-1 mRNA expression were decreased in the HTN+VMH activation group compared to the HTN group. Conclusions: VMH activation could increase SBP and aggravate cardiac remodeling possibly by sympathetic nerve activation and the HIF-1α/PPARα/CPT-1 signaling pathway might be the underlying mechanism.
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Affiliation(s)
- Yuyang Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Zhihao Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Zihan Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Huixin Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Xiao Xu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Zeyan Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Hu Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yuhong Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Zhen Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Meng Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Yanqiu Lai
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Liping Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Xiaoya Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Hong Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiac Autonomic Nervous Research Center, Wuhan University, Wuhan, China.,Department of Cardiology Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
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Subramanian G, Shanmugamprema D, Subramani R, Muthuswamy K, Ponnusamy V, Tankay K, Velusamy T, Krishnan V, Subramaniam S. Anti-Obesity Effect of T. Chebula Fruit Extract on High Fat Diet Induced Obese Mice: A Possible Alternative Therapy. Mol Nutr Food Res 2021; 65:e2001224. [PMID: 33754444 DOI: 10.1002/mnfr.202001224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/18/2021] [Indexed: 12/23/2022]
Abstract
Occurrence of obesity and its associated metabolic disorders continues to escalate. The present study evaluates the anti-obesity effects of ethanolic fruit extract of Terminalia chebula (EETC) on high fat diet induced obese mice. The bioactive compounds present in the EETC is evaluated by Fourier-transform infrared (FT-IR), Gas chromatography-mass spectrometry (GC-MS), and Liquid chromatography-mass spectrometry (LC-MS) analysis. The effects of EETC on energy intake, glucose tolerance, and various biochemical parameters were analyzed using laboratory mice. Relative gene expression of Fatty acid synthase (FAS), Peroxisome proliferator-activated receptors α (PPARα), Carnitine palmitoyltransferase-1 (CPT-1), Tumor necrosis factor alpha (TNF-α) as well as Interleukin 6 (IL-6) were analyzed in liver and adipose tissues. The findings reveal the hypolipidemic and anti-obesity potential of EETC on high fat fed obese mice. EETC exerts its anti-obesity effects by suppressing lipogenesis through reduction in lipogenic enzyme (FAS) expression, increased fatty acid oxidation via PPARα and CPT-1 and by triggering the anti-inflammatory responses. To our knowledge, this is the first report of the effect of EETC on PPARα and CPT-1 in in vivo.
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Affiliation(s)
- Gowtham Subramanian
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Deepankumar Shanmugamprema
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Ramya Subramani
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Karthi Muthuswamy
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Vinithra Ponnusamy
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Kalpana Tankay
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Thirunavukkarasu Velusamy
- Department of Biotechnology, School of Biotechnology and Genetic Engineering, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Vasanth Krishnan
- Molecular Biology Laboratory, Department of Botany, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Selvakumar Subramaniam
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
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Yang X, Yuan Y, Xie D. Low Molecular Pectin Inhibited the Lipid Accumulation by Upregulation of METTL7B. Appl Biochem Biotechnol 2021; 193:1469-1481. [PMID: 33484445 DOI: 10.1007/s12010-021-03486-z] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 01/07/2021] [Indexed: 01/21/2023]
Abstract
Inhibition of lipid accumulation is the key step to prevent nonalcoholic fatty liver (NAFL) progressing to nonalcoholic steatohepatitis. We aimed to study the effect of low-molecular-weight citrus pectin (LCP) against lipid accumulation and the underlying mechanism. Oleic acid (OA)-induced lipid deposition in HepG2 cells was applied to mimic in vitro model of lipid accumulation. Oil Red O (ORO) stain result showed lipid accumulation was significantly reduced, and levels of adipose triglyceride lipase (ATGL) and carnitine palmitoyltransferase-1 (CPT-1), involved in triacylglycerol catabolism and fatty acid β-oxidation, detected by RT-qPCR were increased after OA-stimulated HepG2 cells treated with LCP. RNA sequencing analysis identified 740 differentially expressed genes (DEGs) in OA-stimulated HepG2 cells treated with the LCP group (OA+LCP group), and bioinformatics analysis indicated that some DEGs were enriched in lipid metabolism-related processes and pathways. The expression of the top 8 known DEGs in the OA+LCP group was then verified by RT-qPCR, which showed that fold change (abs) of METTL7B was the highest among the 8 candidates. In addition, overexpression of METTL7B in HepG2 cells significantly inhibited the lipid accumulation and enhanced levels of ATGL and CPT-1. In conclusion, LCP inhibited lipid accumulation through the upregulation of METTL7B, and further enhancement of ATGL and CPT-1 levels. LCP is expected to develop as a promising agent to ameliorate fat accumulation in NAFL.
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Affiliation(s)
- Xiaojin Yang
- Department of Infectious Diseases, Shanghai Fifth People's Hospital, Fudan University, No. 128 Ruili Road, Shanghai, 200240, China
| | - Yinghua Yuan
- Department of Infectious Diseases, Shanghai Fifth People's Hospital, Fudan University, No. 128 Ruili Road, Shanghai, 200240, China.
| | - Desheng Xie
- Department of Infectious Diseases, Shanghai Fifth People's Hospital, Fudan University, No. 128 Ruili Road, Shanghai, 200240, China
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Howard EE, Margolis LM. Intramuscular Mechanisms Mediating Adaptation to Low-Carbohydrate, High-Fat Diets during Exercise Training. Nutrients 2020; 12:E2496. [PMID: 32824957 DOI: 10.3390/nu12092496] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/15/2020] [Accepted: 08/17/2020] [Indexed: 12/01/2022] Open
Abstract
Interest in low-carbohydrate, high-fat (LCHF) diets has increased over recent decades given the theorized benefit of associated intramuscular adaptations and shifts in fuel utilization on endurance exercise performance. Consuming a LCHF diet during exercise training increases the availability of fat (i.e., intramuscular triglyceride stores; plasma free fatty acids) and decreases muscle glycogen stores. These changes in substrate availability increase reliance on fat oxidation for energy production while simultaneously decreasing reliance on carbohydrate oxidation for fuel during submaximal exercise. LCHF diet-mediated changes in substrate oxidation remain even after endogenous or exogenous carbohydrate availability is increased, suggesting that the adaptive response driving changes in fat and carbohydrate oxidation lies within the muscle and persists even when the macronutrient content of the diet is altered. This narrative review explores the intramuscular adaptations underlying increases in fat oxidation and decreases in carbohydrate oxidation with LCHF feeding. The possible effects of LCHF diets on protein metabolism and post-exercise muscle remodeling are also considered.
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Abstract
Significant advances have been made in deciphering the mechanisms underlying fuel-stimulated insulin secretion by pancreatic beta cells. The contribution of the triggering/ATP-sensitive potassium (KATP)-dependent Ca2+ signalling and KATP-independent amplification pathways, that include anaplerosis and lipid signalling of glucose-stimulated insulin secretion (GSIS), are well established. A proposed model included a key role for a metabolic partitioning 'switch', the acetyl-CoA carboxylase (ACC)/malonyl-CoA/carnitine palmitoyltransferase-1 (CPT-1) axis, in beta cell glucose and fatty acid signalling for insulin secretion. This model has gained overwhelming support from a number of studies in recent years and is now refined through its link to the glycerolipid/NEFA cycle that provides lipid signals through its lipolysis arm. Furthermore, acetyl-CoA carboxylase may also control beta cell growth. Here we review the evidence supporting a role for the ACC/malonyl-CoA/CPT-1 axis in the control of GSIS and its particular importance under conditions of elevated fatty acids (e.g. fasting, excess nutrients, hyperlipidaemia and diabetes). We also document how it is linked to a more global lipid signalling system that includes the glycerolipid/NEFA cycle.
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Affiliation(s)
- Marc Prentki
- Department of Nutrition, University of Montreal, Montréal, QC, Canada.
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montréal, QC, Canada.
- Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Viger Tour, 900 rue Saint Denis, Room R08-412, Montréal, QC, H2X 0A9, Canada.
| | - Barbara E Corkey
- Evans Department of Medicine, Obesity Research Center, Boston University School of Medicine, Boston, MA, USA
| | - S R Murthy Madiraju
- Department of Nutrition, University of Montreal, Montréal, QC, Canada
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montréal, QC, Canada
- Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Viger Tour, 900 rue Saint Denis, Room R08-412, Montréal, QC, H2X 0A9, Canada
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9
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Sun Y, Li Y, Liu C, Xue R, Dong B, Huang H, Peng L, Liu J, Dong Y. The role of angiopoietin-like protein 4 in phenylephrine-induced cardiomyocyte hypertrophy. Biosci Rep 2019; 39:BSR20171358. [PMID: 29339422 DOI: 10.1042/BSR20171358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/15/2018] [Accepted: 01/16/2018] [Indexed: 12/20/2022] Open
Abstract
Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional secreted protein that can be induced by fasting, hypoxia and glucocorticoids. ANGPTL4 has been associated with a variety of diseases; however, the role of ANGPTL4 in cardiac hypertrophy remains poorly understood. In our study, we aimed to explore the effect of ANGPTL4 on phenylephrine-induced cardiomyocyte hypertrophy. Our results showed that knockdown of ANGPTL4 expression significantly exacerbated cardiomyocyte hypertrophy, as demonstrated by increased hypertrophic marker expression, including ANP and cell surface area. Moreover, significantly reduced fatty acid oxidation, as featured by decreased CPT-1 levels, was observed in hypertrophic cardiomyocytes following ANGPTL4 down-regulation. Furthermore, knockdown of ANGPLT4 led to down-regulated expression of peroxisome proliferator-activated receptor α (PPARα), which is the key regulator of cardiac fatty acid oxidation. In addition, ANGPTL4 silencing promoted the activation of JNK1/2, and JNK1/2 signaling blockade could restore the level of PPARα and significantly ameliorate the ANGPTL4 knockdown-induced cardiomyocyte hypertrophy. Therefore, our study demonstrated that ANGPTL4 regulates PPARα through JNK1/2 signaling and is required for the inhibition of cardiomyocyte hypertrophy.
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Zheng F, Cai Y. Concurrent exercise improves insulin resistance and nonalcoholic fatty liver disease by upregulating PPAR-γ and genes involved in the beta-oxidation of fatty acids in ApoE-KO mice fed a high-fat diet. Lipids Health Dis 2019; 18:6. [PMID: 30611282 DOI: 10.1186/s12944-018-0933-z] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 11/27/2018] [Indexed: 12/16/2022] Open
Abstract
Objective To emphasize the mechanism of concurrent exercise effect on lipid disorders in insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD). Materials and methods Twenty male ApoE knockout mice were randomly divided into two groups: HFD group (n = 10) fed a high fat diet, and HFDE group (n = 10) with high-fat diet intervention for 12 weeks and swimming exercise. Other ten healthy male C57BL/6 J mice were fed a normal diet, and included as control group. Retro-orbital blood samples were collected for biochemical analysis. Oil red O staining of liver tissues was performed to confirm the exercise effect. Western blotting was performed to evaluate the expressions of PPAR-γ, CPT-1, MCAD. Results The levels of TG, TC, LDL, FFA, FIN, FPG and Homa-IRI in the HFD group were significantly higher than ND group, while these were markedly decreased in the HFDE group compared with HFD group. The Oil Red O staining of liver samples further confirmed the exercise effect on the change of lipid deposition in the liver. Western blotting showed increased expressions of PPAR-γ, CPT-1, MCAD induced by high fat diet were significantly downregulated by exercise. Conclusion A concurrent 12-week exercise protocol alleviated the lipid metabolism disorders of IR and NAFLD, probably via PPAR-γ/CPT-1/MCAD signaling.
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Liou CJ, Wei CH, Chen YL, Cheng CY, Wang CL, Huang WC. Fisetin Protects Against Hepatic Steatosis Through Regulation of the Sirt1/AMPK and Fatty Acid β-Oxidation Signaling Pathway in High-Fat Diet-Induced Obese Mice. Cell Physiol Biochem 2018; 49:1870-1884. [PMID: 30235452 DOI: 10.1159/000493650] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 09/12/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND/AIMS Fisetin is a naturally abundant flavonoid isolated from various fruits and vegetables that was recently identified to have potential biological functions in improving allergic airway inflammation, as well as anti-oxidative and anti-tumor properties. Fisetin has also been demonstrated to have anti-obesity properties in mice. However, the effect of fisetin on nonalcoholic fatty liver disease (NAFLD) is still elusive. Thus, the present study evaluated whether fisetin improves hepatic steatosis in high-fat diet (HFD)-induced obese mice and regulates lipid metabolism of FL83B hepatocytes in vitro. METHODS NAFLD was induced by HFD in male C57BL/6 mice. The mice were then injected intraperitoneally with fisetin for 10 weeks. In another experiment, FL83B cells were challenged with oleic acid to induce lipid accumulation and treated with various concentrations of fisetin. RESULTS NAFLD mice treated with fisetin had decreased body weight and epididymal adipose tissue weight compared to NAFLD mice. Fisetin treatment also reduced liver lipid droplet and hepatocyte steatosis, alleviated serum free fatty acid, and leptin concentrations, significantly decreased fatty acid synthase, and significantly increased phosphorylation of AMPKα and the production of sirt-1 and carnitine palmitoyltransferase I in the liver tissue. In vitro, fisetin decreased lipid accumulation and increased lipolysis and β-oxidation in hepatocytes. CONCLUSION This study suggests that fisetin is a potential novel treatment for alleviating hepatic lipid metabolism and improving NAFLD in mice via activation of the sirt1/AMPK and β-oxidation pathway.
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Affiliation(s)
- Chian-Jiun Liou
- Department of Nursing, Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Taoyuan, Taiwan.,Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Ciao-Han Wei
- Graduate Institute of Health Industry Technology, Research Center for Food and Cosmetic Safety, Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Ya-Ling Chen
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan.,Department of Nutrition and Health Sciences, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Ching-Yi Cheng
- Graduate Institute of Health Industry Technology, Research Center for Food and Cosmetic Safety, Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan.,Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan.,Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan
| | - Chia-Ling Wang
- Graduate Institute of Health Industry Technology, Research Center for Food and Cosmetic Safety, Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Wen-Chung Huang
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan.,Graduate Institute of Health Industry Technology, Research Center for Food and Cosmetic Safety, Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan
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12
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Divakaruni AS, Hsieh WY, Minarrieta L, Duong TN, Kim KKO, Desousa BR, Andreyev AY, Bowman CE, Caradonna K, Dranka BP, Ferrick DA, Liesa M, Stiles L, Rogers GW, Braas D, Ciaraldi TP, Wolfgang MJ, Sparwasser T, Berod L, Bensinger SJ, Murphy AN. Etomoxir Inhibits Macrophage Polarization by Disrupting CoA Homeostasis. Cell Metab 2018; 28:490-503.e7. [PMID: 30043752 PMCID: PMC6125190 DOI: 10.1016/j.cmet.2018.06.001] [Citation(s) in RCA: 213] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 04/20/2018] [Accepted: 06/02/2018] [Indexed: 12/12/2022]
Abstract
Long-chain fatty acid (LCFA) oxidation has been shown to play an important role in interleukin-4 (IL-4)-mediated macrophage polarization (M(IL-4)). However, many of these conclusions are based on the inhibition of carnitine palmitoyltransferase-1 with high concentrations of etomoxir that far exceed what is required to inhibit enzyme activity (EC90 < 3 μM). We employ genetic and pharmacologic models to demonstrate that LCFA oxidation is largely dispensable for IL-4-driven polarization. Unexpectedly, high concentrations of etomoxir retained the ability to disrupt M(IL-4) polarization in the absence of Cpt1a or Cpt2 expression. Although excess etomoxir inhibits the adenine nucleotide translocase, oxidative phosphorylation is surprisingly dispensable for M(IL-4). Instead, the block in polarization was traced to depletion of intracellular free coenzyme A (CoA), likely resulting from conversion of the pro-drug etomoxir into active etomoxiryl CoA. These studies help explain the effect(s) of excess etomoxir on immune cells and reveal an unappreciated role for CoA metabolism in macrophage polarization.
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Affiliation(s)
- Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Wei Yuan Hsieh
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lucía Minarrieta
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Tin N Duong
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Kristen K O Kim
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Brandon R Desousa
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Alexander Y Andreyev
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Caitlyn E Bowman
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kacey Caradonna
- Agilent Technologies, 5301 Stevens Creek Boulevard, Santa Clara, CA 95051, USA
| | - Brian P Dranka
- Agilent Technologies, 5301 Stevens Creek Boulevard, Santa Clara, CA 95051, USA
| | - David A Ferrick
- Agilent Technologies, 5301 Stevens Creek Boulevard, Santa Clara, CA 95051, USA
| | - Marc Liesa
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Linsey Stiles
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - George W Rogers
- Agilent Technologies, 5301 Stevens Creek Boulevard, Santa Clara, CA 95051, USA
| | - Daniel Braas
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; UCLA Metabolomics Center and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Theodore P Ciaraldi
- Veterans Affairs San Diego Healthcare System, La Jolla, CA 92161, USA; Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael J Wolfgang
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tim Sparwasser
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Luciana Berod
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Steven J Bensinger
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Anne N Murphy
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
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13
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Kim B, Woo MJ, Park CS, Lee SH, Kim JS, Kim B, An S, Kim SH. Hovenia Dulcis Extract Reduces Lipid Accumulation in Oleic Acid-Induced Steatosis of Hep G2 Cells via Activation of AMPK and PPARα/ CPT-1 Pathway and in Acute Hyperlipidemia Mouse Model. Phytother Res 2016; 31:132-139. [PMID: 27762456 DOI: 10.1002/ptr.5741] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/22/2016] [Accepted: 09/26/2016] [Indexed: 12/28/2022]
Abstract
Hovenia dulcis Thunb. (HDT) was known to have anti-fatigue, anti-diabetes, neuroprotective, and hepatoprotective effects. In the present study, the anti-fatty liver mechanism of HDT was elucidated in oleic acid (OA)-treated Hep G2 cells and acute hyperlipidemia mouse model using Triton WR-1339. Here, HDT activated p-AMP-activated protein kinase (p-AMPK), proliferator activated receptor-α, carnitine palmitoyltransferase and also inhibited the expression of lipogenesis and cholesterol synthesis proteins, such as 3-hydroxy-3-methylglutaryl-CoA reductase, sterol regulatory element binding protein-1c, SREBP-2, and fatty acid synthase in OA-treated Hep G2 cells. Conversely, AMPK inhibitor compound C blocked the anti-fatty liver effect of HDT to induce AMPK phosphorylation and decrease 3-hydroxy-3-methylglutaryl-CoA reductase and lipid accumulation by oil red O staining in OA-treated Hep G2 cells. Additionally, HDT pretreatment protected against the increase of serum total cholesterol, triglyceride, low-density lipoprotein cholesterol and phospholipid in an acute hyperlipidemia mouse model with enhancement of glutathione reductase, glutathione peroxidase, superoxide dismutase, and catalase activities. Taken together, HDT inhibits OA-induced hepatic lipid accumulation via activation of AMPK and proliferator activated receptor-α/carnitine palmitoyltransferase signaling and enhancement of antioxidant activity as a potent candidate for nonalcoholic fatty liver disease and hyperlipidemia. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Bonglee Kim
- College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Korea
| | - Moon-Jea Woo
- Kwang dong Pharmaceutical Co., Ltd., Seoul, 137-875, Korea
| | - Chul-Soo Park
- Kwang dong Pharmaceutical Co., Ltd., Seoul, 137-875, Korea
| | - Sang-Hun Lee
- Kwang dong Pharmaceutical Co., Ltd., Seoul, 137-875, Korea
| | - Jin-Soo Kim
- Kwang dong Pharmaceutical Co., Ltd., Seoul, 137-875, Korea
| | - Boim Kim
- College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Korea
| | - Seho An
- College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Korea
| | - Sung-Hoon Kim
- College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Korea
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14
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Tsukuda Y, Suda G, Tsunematsu S, Ito J, Sato F, Terashita K, Nakai M, Sho T, Maehara O, Shimazaki T, Kimura M, Morikawa K, Natsuizaka M, Ogawa K, Ohnishi S, Chuma M, Sakamoto N. Anti-adipogenic and antiviral effects of l-carnitine on hepatitis C virus infection. J Med Virol 2016; 89:857-866. [PMID: 27664407 DOI: 10.1002/jmv.24692] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2016] [Indexed: 12/11/2022]
Abstract
Hepatitis C virus (HCV) has been reported to hijack fatty acid metabolism in infected hepatocytes, taking advantage of lipid droplets for virus assembly. In this study, we analyzed the anti-HCV activity of l-carnitine, a substance involved in the transport of fatty acids into mitochondria. JFH-1 or HCV replicon-transfected Huh7.5.1 cells were treated with or without l-carnitine to examine its anti-HCV effects. The effects of l-carnitine on HCV entry, HCV-induced adipogenesis and lipid droplet formation, and HCV-induced oxidative stress were examined. Treatment of JFH-1-infected cells with l-carnitine inhibited HCV propagation in a concentration-dependent manner. In contrast, l-carnitine had no anti-HCV activity in the HCV replicon system, which is lacking viral assembly. In addition, l-carnitine did not affect HCV entry. However, l-carnitine treatment decreased intracellular lipid droplets, which are crucial for HCV assembly in JFH-1-infected cells. The expression level of CPT-1 was decreased in JFH-1-infected cells, and l-carnitine treatment restored this expression. HCV-infected cells exhibited increased production of reactive oxygen species and glutathione oxidation. l-carnitine decreased oxidative stress induced by JFH-1-infection, as shown by glutathione/glutathione disulfide assays and MitoSOX staining. l-carnitine exhibited anti-HCV activity, possibly by inhibiting HCV assembly and through its anti-adipogenic activity in HCV-infected cells. Moreover, l-carnitine has antioxidant properties in HCV-infected hepatocytes. Overall, these results indicated that l-carnitine may be an effective adjunctive agent in antiviral therapies to treat chronic hepatitis C. J. Med. Virol. 89:857-866, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Yoko Tsukuda
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Goki Suda
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | | | - Jun Ito
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Fumiyuki Sato
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Katsumi Terashita
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Masato Nakai
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Takuya Sho
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Osamu Maehara
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Tomoe Shimazaki
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Megumi Kimura
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Kenichi Morikawa
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Mitsuteru Natsuizaka
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Koji Ogawa
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Shunsuke Ohnishi
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Makoto Chuma
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
| | - Naoya Sakamoto
- Department of Gastroenterology and Hepatology, Hokkaido University, Sapporo, Japan
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15
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Toral M, Romero M, Jiménez R, Mahmoud AM, Barroso E, Gómez-Guzmán M, Sánchez M, Cogolludo Á, García-Redondo AB, Briones AM, Vázquez-Carrera M, Pérez-Vizcaíno F, Duarte J. Carnitine palmitoyltransferase-1 up-regulation by PPAR-β/δ prevents lipid-induced endothelial dysfunction. Clin Sci (Lond) 2015; 129:823-37. [PMID: 26253087 DOI: 10.1042/CS20150111] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Fatty acids cause endothelial dysfunction involving increased ROS (reactive oxygen species) and reduced NO (nitric oxide) bioavailability. We show that in MAECs (mouse aortic endothelial cells), the PPARβ/δ (peroxisome- proliferator-activated receptor β/δ) agonist GW0742 prevented the decreased A23187-stimulated NO production, phosphorylation of eNOS (endothelial nitric oxide synthase) at Ser1177 and increased intracellular ROS levels caused by exposure to palmitate in vitro. The impaired endothelium-dependent relaxation to acetylcholine in mouse aorta induced by palmitate was restored by GW0742. In vivo, GW0742 treatment prevented the reduced aortic relaxation, phosphorylation of eNOS at Ser1177, and increased ROS production and NADPH oxidase in mice fed on a high-fat diet. The PPARβ/δ antagonist GSK0660 abolished all of these protective effects induced by GW0742. This agonist enhanced the expression of CPT (carnitine palmitoyltransferase)-1. The effects of GW0742 on acetylcholine- induced relaxation in aorta and on NO and ROS production in MAECs exposed to palmitate were abolished by the CPT-1 inhibitor etomoxir or by siRNA targeting CPT-1. GW0742 also inhibited the increase in DAG (diacylglycerol), PKCα/βII (protein kinase Cα/βII) activation, and phosphorylation of eNOS at Thr495 induced by palmitate in MAECs, which were abolished by etomoxir. In conclusion, PPARβ/δ activation restored the lipid-induced endothelial dysfunction by up-regulation of CPT-1, thus reducing DAG accumulation and the subsequent PKC-mediated ROS production and eNOS inhibition.
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Abstract
The increased prevalence of hyperlipidemia, hypertriglyceridemia, hypercholesterolemia, and fatty liver disease has provided increasingly negative connotations toward lipids. However, it is important to remember that lipids are essential components supporting life. Lipids are a class of molecules defined by their inherent insolubility in water. In biological systems, lipids are either hydrophobic (containing only polar groups) or amphipathic (possess polar and nonpolar groups). These characteristics lend lipids to be highly diverse with a multitude of functions including hormone and membrane synthesis, involvement in numerous signaling cascades, as well as serving as a source of metabolic fuel supporting energy production. Exercise can induce changes in the lipid composition of membranes that effect fluidity and cellular function, as well as modify the cellular and circulating environment of lipids that regulate signaling cascades. The purpose of this chapter is to focus on lipid utilization as metabolic fuel in response to acute and chronic exercise training. Lipids utilized as an energy source during exercise include circulating fatty acids bound to albumin, triglycerides stored in very-low-density lipoprotein, and intramuscular triglyceride stores. Dynamic changes in these lipid pools during and after exercise are discussed, as well as key factors that may be responsible for regulating changes in fat oxidation in response to varying exercise conditions.
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Affiliation(s)
- Robert C Noland
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
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17
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Wang S, Moustaid-Moussa N, Chen L, Mo H, Shastri A, Su R, Bapat P, Kwun I, Shen CL. Novel insights of dietary polyphenols and obesity. J Nutr Biochem. 2014;25:1-18. [PMID: 24314860 DOI: 10.1016/j.jnutbio.2013.09.001] [Citation(s) in RCA: 594] [Impact Index Per Article: 59.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 07/15/2013] [Accepted: 09/04/2013] [Indexed: 12/14/2022]
Abstract
The prevalence of obesity has steadily increased over the past three decades both in the United States and worldwide. Recent studies have shown the role of dietary polyphenols in the prevention of obesity and obesity-related chronic diseases. Here, we evaluated the impact of commonly consumed polyphenols, including green tea catechins, especially epigallocatechin gallates, resveratrol and curcumin, on obesity and obesity-related inflammation. Cellular studies demonstrated that these dietary polyphenols reduce viability of adipocytes and proliferation of preadipocytes, suppress adipocyte differentiation and triglyceride accumulation, stimulate lipolysis and fatty acid β-oxidation, and reduce inflammation. Concomitantly, the polyphenols modulate signaling pathways including the adenosine-monophosphate-activated protein kinase, peroxisome proliferator activated receptor γ, CCAAT/enhancer binding protein α, peroxisome proliferator activator receptor gamma activator 1-alpha, sirtuin 1, sterol regulatory element binding protein-1c, uncoupling proteins 1 and 2, and nuclear factor-κB that regulate adipogenesis, antioxidant and anti-inflammatory responses. Animal studies strongly suggest that commonly consumed polyphenols described in this review have a pronounced effect on obesity as shown by lower body weight, fat mass and triglycerides through enhancing energy expenditure and fat utilization, and modulating glucose hemostasis. Limited human studies have been conducted in this area and are inconsistent about the antiobesity impact of dietary polyphenols probably due to the various study designs and lengths, variation among subjects (age, gender, ethnicity), chemical forms of the dietary polyphenols used and confounding factors such as other weight-reducing agents. Future randomized controlled trials are warranted to reconcile the discrepancies between preclinical efficacies and inconclusive clinic outcomes of these polyphenols.
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Mitsutomi K, Masaki T, Shimasaki T, Gotoh K, Chiba S, Kakuma T, Shibata H. Effects of a nonnutritive sweetener on body adiposity and energy metabolism in mice with diet-induced obesity. Metabolism 2014; 63:69-78. [PMID: 24140095 DOI: 10.1016/j.metabol.2013.09.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [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] [Received: 04/16/2013] [Revised: 08/29/2013] [Accepted: 09/04/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Nonnutritive sweeteners (NNSs) have been studied in terms of their potential roles in type 2 diabetes, obesity, and related metabolic disorders. Several studies have suggested that NNSs have several specific effects on metabolism such as reduced postprandial hyperglycemia and insulin resistance. However, the detailed effects of NNSs on body adiposity and energy metabolism have not been fully elucidated. We investigated the effects of an NNS on energy metabolism in mice with diet-induced obesity (DIO). METHODS DIO mice were divided into NNS-administered (4% NNS in drinking water), sucrose-administered (33% sucrose in drinking water), and control (normal water) groups. After supplementation for 4 weeks, metabolic parameters, including uncoupling protein (UCP) levels and energy expenditure, were assessed. RESULTS Sucrose supplementation increased hyperglycemia, body adiposity, and body weight compared to the NNS-administered and control groups (P<0.05 for each). In addition, NNS supplementation decreased hyperglycemia compared to the sucrose-administered group (P<0.05). Interestingly, NNS supplementation increased body adiposity, which was accompanied by hyperinsulinemia, compared to controls (P<0.05 for each). NNS also increased leptin levels in white adipose tissue and triglyceride levels in tissues compared to controls (P<0.05 for each). Notably, compared to controls, NNS supplementation decreased the UCP1 level in brown adipose tissue and decreased O2 consumption in the dark phase. CONCLUSIONS NNSs may be good sugar substitutes for people with hyperglycemia, but appear to influence energy metabolism in DIO mice.
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Affiliation(s)
- Kimihiko Mitsutomi
- Department of Endocrinology and metabolism, Faculty of Medicine, Oita University, Yufu, Oita, 879-5593, Japan
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Serviddio G, Bellanti F, Vendemiale G. Free radical biology for medicine: learning from nonalcoholic fatty liver disease. Free Radic Biol Med 2013; 65:952-968. [PMID: 23994574 DOI: 10.1016/j.freeradbiomed.2013.08.174] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [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] [Received: 03/04/2013] [Revised: 08/20/2013] [Accepted: 08/20/2013] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species, when released under controlled conditions and limited amounts, contribute to cellular proliferation, senescence, and survival by acting as signaling intermediates. In past decades there has been an epidemic diffusion of nonalcoholic fatty liver disease (NAFLD) that represents the result of the impairment of lipid metabolism, redox imbalance, and insulin resistance in the liver. To date, most studies and reviews have been focused on the molecular mechanisms by which fatty liver progresses to steatohepatitis, but the processes leading toward the development of hepatic steatosis in NAFLD are not fully understood yet. Several nuclear receptors, such as peroxisome proliferator-activated receptors (PPARs) α/γ/δ, PPARγ coactivators 1α and 1β, sterol-regulatory element-binding proteins, AMP-activated protein kinase, liver-X-receptors, and farnesoid-X-receptor, play key roles in the regulation of lipid homeostasis during the pathogenesis of NAFLD. These nuclear receptors may act as redox sensors and may modulate various metabolic pathways in response to specific molecules that act as ligands. It is conceivable that a redox-dependent modulation of lipid metabolism, nuclear receptor-mediated, could cause the development of hepatic steatosis and insulin resistance. Thus, this network may represent a potential therapeutic target for the treatment and prevention of hepatic steatosis and its progression to steatohepatitis. This review summarizes the redox-dependent factors that contribute to metabolism alterations in fatty liver with a focus on the redox control of nuclear receptors in normal liver as well as in NAFLD.
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Affiliation(s)
- Gaetano Serviddio
- C.U.R.E. Centre for Liver Disease Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy.
| | - Francesco Bellanti
- C.U.R.E. Centre for Liver Disease Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Gianluigi Vendemiale
- C.U.R.E. Centre for Liver Disease Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
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Hsu WH, Chen TH, Lee BH, Hsu YW, Pan TM. Monascin and ankaflavin act as natural AMPK activators with PPARα agonist activity to down-regulate nonalcoholic steatohepatitis in high-fat diet-fed C57BL/6 mice. Food Chem Toxicol 2013; 64:94-103. [PMID: 24275089 DOI: 10.1016/j.fct.2013.11.015] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 09/18/2013] [Accepted: 11/13/2013] [Indexed: 12/14/2022]
Abstract
Yellow pigments monascin (MS) and ankaflavin (AK) are secondary metabolites derived from Monascus-fermented products. The hypolipidemic and anti-inflammatory effects of MS and AK indicate that they have potential on preventing or curing nonalcoholic fatty liver disease (NAFLD). Oleic acid (OA) and high-fat diet were used to induce steatosis in FL83B hepatocytes and NAFLD in mice, respectively. We found that both MS and AK prevented fatty acid accumulation in hepatocytes by inhibiting fatty acid uptake, lipogenesis, and promoting fatty acid beta-oxidation mediated by activating peroxisome proliferator-activated receptor (PPAR)-α and AMP-activated kinase (AMPK). Furthermore, MS and AK significantly attenuated high-fat diet-induced elevation of total cholesterol (TC), triaceylglycerol (TG), free fatty acid (FFA), and low density lipoprotein-cholesterol (LDL-C) in plasma. MS and AK promoted AMPK phosphorylation, suppressed the steatosis-related mRNA expression and inflammatory cytokines secretion, as well as upregulated farnesoid X receptor (FXR), peroxisome proliferator-activated receptor gamma co-activator (PGC)-1α, and PPARα expression to induce fatty acid oxidation in the liver of mice. We provided evidence that MS and AK act as PPARα agonists to upregulate AMPK activity and attenuate NAFLD. MS and AK may be supplied in food supplements or developed as functional foods to reduce the risk of diabetes and obesity.
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Affiliation(s)
- Wei-Hsuan Hsu
- Department of Biochemical Science & Technology, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ting-Hung Chen
- Department of Biochemical Science & Technology, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Bao-Hong Lee
- Department of Biochemical Science & Technology, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ya-Wen Hsu
- R&D Division, SunWay Biotechnology Company Limited, Taipei, Taiwan
| | - Tzu-Ming Pan
- Department of Biochemical Science & Technology, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
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Chen H, Zhang L, Li X, Li X, Sun G, Yuan X, Lei L, Liu J, Yin L, Deng Q, Wang J, Liu Z, Yang W, Wang Z, Zhang H, Liu G. Adiponectin activates the AMPK signaling pathway to regulate lipid metabolism in bovine hepatocytes. J Steroid Biochem Mol Biol 2013; 138:445-54. [PMID: 23994141 DOI: 10.1016/j.jsbmb.2013.08.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [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] [Received: 04/10/2013] [Revised: 08/17/2013] [Accepted: 08/21/2013] [Indexed: 12/11/2022]
Abstract
Adiponectin (Ad) plays a crucial role in hepatic lipid metabolism. However, the regulating mechanism of hepatic lipid metabolism by Ad in dairy cows is unclear. Hepatocytes from a newborn female calf were cultured in vitro and treated with different concentrations of Ad and BML-275 (an AMPKα inhibitor). The results showed that Ad significantly increased the expression of two Ad receptors. Furthermore, the phosphorylation and activity of AMPKα, as well as the expression levels and transcriptional activity of peroxisome proliferator activated receptor-α (PPARα) and its target genes involved in lipid oxidation, showed a corresponding trend of upregulation. However, the expression levels and transcriptional activity of sterol regulatory element binding protein 1c (SREBP-1c) and carbohydrate-responsive element-binding protein (ChREBP) decreased in a similar manner. When BML-275 was added, the p-AMPKα level as well as the expression and activity of PPARα and its target genes were significantly decreased. However, the expression levels of SREBP-1c, ChREBP and their target genes showed a trend of upregulation. Furthermore, the triglyceride (TG) content was significantly decreased in the Ad-treated groups. These results indicate that Ad activates the AMPK signaling pathway and mediates lipid metabolism in bovine hepatocytes cultured in vitro by promoting lipid oxidation, suppressing lipid synthesis and reducing hepatic lipid accumulation.
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Affiliation(s)
- Hui Chen
- College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, Jilin 130062, China
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Saraswathi V, Ramnanan CJ, Wilks AW, Desouza CV, Eller AA, Murali G, Ramalingam R, Milne GL, Coate KC, Edgerton DS. Impact of hematopoietic cyclooxygenase-1 deficiency on obesity-linked adipose tissue inflammation and metabolic disorders in mice. Metabolism 2013; 62:1673-85. [PMID: 23987235 PMCID: PMC4845736 DOI: 10.1016/j.metabol.2013.07.007] [Citation(s) in RCA: 20] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 06/13/2013] [Accepted: 07/16/2013] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Adipose tissue (AT)-specific inflammation is considered to mediate the pathological consequences of obesity and macrophages are known to activate inflammatory pathways in obese AT. Because cyclooxygenases play a central role in regulating the inflammatory processes, we sought to determine the role of hematopoietic cyclooxygenase-1 (COX-1) in modulating AT inflammation in obesity. MATERIALS/METHODS Bone marrow transplantation was performed to delete COX-1 in hematopoietic cells. Briefly, female wild type (wt) mice were lethally irradiated and injected with bone marrow (BM) cells collected from wild type (COX-1+/+) or COX-1 knock-out (COX-1-/-) donor mice. The mice were fed a high fat diet for 16 weeks. RESULTS The mice that received COX-1-/- bone marrow (BM-COX-1-/-) exhibited a significant increase in fasting glucose, total cholesterol and triglycerides in the circulation compared to control (BM-COX-1+/+) mice. Markers of AT-inflammation were increased and were associated with increased leptin and decreased adiponectin in plasma. Hepatic inflammation was reduced with a concomitant reduction in TXB2 levels. The hepatic mRNA expression of genes involved in lipogenesis and lipid transport was increased while expression of genes involved in regulating hepatic glucose output was reduced in BM-COX-1-/- mice. Finally, renal inflammation and markers of renal glucose release were increased in BM-COX-1-/- mice. CONCLUSION Hematopoietic COX-1 deletion results in impairments in metabolic homeostasis which may be partly due to increased AT inflammation and dysregulated adipokine profile. An increase in renal glucose release and hepatic lipogenesis/lipid transport may also play a role, at least in part, in mediating hyperglycemia and dyslipidemia, respectively.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics; Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism; Department of Cellular and Integrative Physiology, University of Nebraska Medical Center; VA Nebraska Western Iowa Health Care System, Omaha, NE.
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de Sain-van der Velden MGM, Diekman EF, Jans JJ, van der Ham M, Prinsen BHCMT, Visser G, Verhoeven-Duif NM. Differences between acylcarnitine profiles in plasma and bloodspots. Mol Genet Metab 2013; 110:116-21. [PMID: 23639448 DOI: 10.1016/j.ymgme.2013.04.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [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] [Received: 04/04/2013] [Accepted: 04/04/2013] [Indexed: 10/27/2022]
Abstract
UNLABELLED Quantification of acylcarnitines is used for screening and diagnosis of inborn error of metabolism (IEM). While newborn screening is performed in dried blood spots (DBSs), general metabolic investigation is often performed in plasma. Information on the correlation between plasma and DBS acylcarnitine profiles is scarce. In this study, we directly compared acylcarnitine concentrations measured in DBS with those in the corresponding plasma sample. Additionally, we tested whether ratios of acylcarnitines in both matrices are helpful for diagnostic purpose when primary markers fail. STUDY DESIGN DBS and plasma were obtained from controls and patients with a known IEM. (Acyl)carnitines were converted to their corresponding butyl esters and analyzed using HPLC/MS/MS. RESULTS Free carnitine concentrations were 36% higher in plasma compared to DBS. In contrast, in patients with carnitine palmitoyltransferase 1 (CPT-1) deficiency free carnitine concentration in DBS was 4 times the concentration measured in plasma. In carnitine palmitoyltransferase 2 (CPT-2) deficiency, primary diagnostic markers were abnormal in plasma but could also be normal in DBS. The calculated ratios for CPT-1 (C0/(C16+C18)) and CPT-2 ((C16+C18:1)/C2) revealed abnormal values in plasma. However, normal ratios were found in DBS of two (out of five) samples obtained from patients diagnosed with CPT-2. CONCLUSIONS Relying on primary acylcarnitine markers, CPT-1 deficiency can be missed when analysis is performed in plasma, whereas CPT-2 deficiency can be missed when analysis is performed in DBS. Ratios of the primary markers to other acylcarnitines restore diagnostic recognition completely for CPT-1 and CPT-2 in plasma, while CPT-2 can still be missed in DBS.
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Affiliation(s)
- Monique G M de Sain-van der Velden
- Department of Medical Genetics, UMC Utrecht, The Netherlands Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, Utrecht, The Netherlands.
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Guebre-Egziabher F, Alix PM, Koppe L, Pelletier CC, Kalbacher E, Fouque D, Soulage CO. Ectopic lipid accumulation: A potential cause for metabolic disturbances and a contributor to the alteration of kidney function. Biochimie 2013; 95:1971-9. [PMID: 23896376 DOI: 10.1016/j.biochi.2013.07.017] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/18/2013] [Indexed: 01/06/2023]
Abstract
Ectopic lipid accumulation is now known to be a mechanism that contributes to organ injury in the context of metabolic diseases. In muscle and liver, accumulation of lipids impairs insulin signaling. This hypothesis accounts for the mechanism of insulin resistance in obesity, type 2 diabetes, aging and lipodystrophy. Increasing data suggest that lipid accumulation in the kidneys could also contribute to the alteration of kidney function in the context of metabolic syndrome and obesity. Furthermore and more unexpectedly, animal models of kidney disease exhibit a decreased adiposity and ectopic lipid redistribution suggesting that kidney disease may be a state of lipodystrophy. However, whether this abnormal lipid partitioning during chronic kidney disease (CKD) may have any functional impact in these tissues needs to be investigated. Here, we provide a perspective by defining the problem and analyzing the possible causes and consequences. Further human studies are required to strengthen these observations, and provide novel therapeutic approaches.
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Affiliation(s)
- Fitsum Guebre-Egziabher
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France; Hospices Civils de Lyon, Department of Nephrology, Hôpital E Herriot, Lyon F-69003, France.
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Gulvady AA, Ciolino HP, Cabrera RM, Jolly CA. Resveratrol inhibits the deleterious effects of diet-induced obesity on thymic function. J Nutr Biochem 2013; 24:1625-33. [PMID: 23561698 DOI: 10.1016/j.jnutbio.2013.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [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: 08/30/2012] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 01/06/2023]
Abstract
Obesity is associated with an increased risk of infectious diseases. It has been shown to have deleterious effects on cell-mediated immunity, including reducing thymocyte numbers and altering responses of thymocytes to pathogens. In the current study, we examined the efficacy of the antiobesity phytochemical resveratrol in preventing the deleterious effects of a high-fat diet on thymic anatomy and function. Compared to C57Bl/6 male mice fed a low-fat diet, mice on a high-fat diet had a significant increase in thymic weight and lipid content, and a disrupted anatomy, including a reduction of the medullary compartment and absence of a corticomedullary junction. There were a decrease in thymic cellularity and mature T-cell output, and a disrupted T-cell maturation, as evidenced by increased double-negative and decreased single- and double-positive thymocytes. Mice that had been fed resveratrol along with a high-fat diet had a dose-dependent reversal in all these parameters. Western blots from thymi showed that obese mice had lower levels of the key stimulators of lipid metabolism, phospho-5' adenosine monophosphate-activated protein kinase and its downstream target, carnitine palmitoyl transferase-1; this was restored to normal levels in resveratrol-fed mice. Resveratrol also reversed an increase in glycerol-3-phosphate acyltransferase-1, the enzyme that catalyzes the first step in triglycerol synthesis. Taken together, these results indicate that resveratrol is a potent inhibitor of the deleterious effects of diet-induced obesity on thymic anatomy and function, and this may hold promise in preventing obesity-related deficits in cell-mediated immunity.
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Affiliation(s)
- Apeksha A Gulvady
- Department of Nutritional Sciences, Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX 78723, USA
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